ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

ELECTRONIC POSTER SESSION • NEURO A
2843 -2866 Parkinson's Neurodegenerative
2867 -2890 Advanced Imaging of Dementia
2891 -2914 Advanced Neuroimaging: Traumatic Brain Injury & Other Clinical Applications
2915 -2938 Animal Models & Clinical Studies of Stroke
2939 -2956 Normal Developing Brain
2957 -2980 Advanced Fetal & Pediatric CNS Imaging
2981 -3004 Neurovascular Diseases
3005 -3028 High Resolution Brain Anatomy & Morphology

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (10:45-11:45) Exhibition Hall
Parkinson's Neurodegenerative

  Computer #  
2843.   1 Study of Articulatory Movement from the Single Slice Dynamic Imaging of the Vocal Tract in Parkinsonism
S. Senthil Kumaran1, Sunita Gudwani1, Mohit Saxena2, and Madhuri Behari2
1Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of Neurology, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
Parkinsonism is a degenerative motor disorder where speech production is affected early prior to other voluntary motor functions. Due to this perceptual feature the communication becomes difficult progressively debilitating quality of life of the subject. Clinically assessment of vocal tract dynamics and acoustic analysis are essential for planning management. This study explores the use of single slice real time trufi sequence dynamic MR images as a diagnostic tool for spatial and temporal vocal tract shaping.

 
2844.   2 Short Term Visual Memory Dysfunction in Parkinsonism
Mohit Saxena1, S. Senthil Kumaran2, Madhuri Behari1, and Vinay Goyal1
1Department of Neurology, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
Non-motor cognitive impairment like dysfunctions in executive/ speech/ attention/ memory loss are evident in Parkinsonism due to loss of dopaminergic neurons, in nigrostriatal tracts and mesocortical pathway. Identifying cognitive decline may help us understand the short term working memory deficit among the three types of parkinsonism and response to Levodopa.

 
2845.   3 Differential Diffusivity in Parkinsonism
Mohit Saxena1, S. Senthil Kumaran2, Madhuri Behari1, and Vinay Goyal1
1Department of Neurology, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
Parkinson’s Disease presents difficulty in coordinated movements due to loss of dopaminergic neurons in the substantia nigra. We observed a significant loss in the whole brain fibers in PD subjects as compared to in controls. We observed significantly low FA values in the SMA and thalamus. DTI studies may offer a better understanding of the degeneration in the motor predominant areas like primary motor cortex and supplementary areas and striatum.

 
2846.   4 Preservation of Deep Gray Nuclear Tissue Contrast and Utility of Thalamus as an Internal Standard in Inversion Recovery MR Images at High and Low RF Power in Parkinson’s Patients Treated with Deep Brain Neurostimulators
Subhendra Sarkar1, Ron Alterman2, Rafael Rojas1, Douglas Teich1, Jeremy Stormann1, Ines Cabral-Goncalves1, David Hackney1, and Efstathios Papavassiliou2
1Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, BOSTON, Massachusetts, United States, 2Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, BOSTON, Massachusetts, United States

 
We have used a low-SAR modification to FSEIR sequence and proposed Thalamus as an internal standard to test tissue contrasts and borders of deep brain nuclei in Parkinson's Disease for neurostimulator implantation. With high quality at low-SAR this approach may offer direct MR usage and reduce the dependency on microelectrode recording during DBS surgery.

 
2847.   5 Functional Connectivity in Patients with Progressive Sopranuclear Palsy Is Modulated by Cerebellar Intermittent Theta Burst Stimulation
Chiara Mastropasqua1,2, Marco Bozzali3, Viviana Ponzo4, Mara Cercignani1,5, Carlo Caltagirone6,7, Livia Brusa8, and Giacomo Koch4,9
1Neuroimaging Laboratory, IRCCS Santa Lucia, Rome, Italy, 2Department of Neuroscience, Trieste University, Trieste, Italy, 3Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, 4Department of Clinical and Behavioural Neurology, IRCCS Santa Lucia, Rome, Italy, 5Clinical Imaging Sciences Centre, Brighton & Sussex Medical School, Falmer, United Kingdom, 6Department of Clinical and Behavioural Neurology, IRCCS Santa Lucia Foundation, Rome, Italy, 7Dep. of Neuroscience, University of Rome Tor Vergata, Rome, Italy, 8Dep. of Neurology, S. Eugenio Hospital, Rome, Italy, 9Stroke Unit, Department of Neuroscience, University of Rome Tor Vergata, Rome, Italy

 
Progressive Sopranuclear Palsy (PSP) is a degenerative parkinsonism clinically characterized by postural instability and sopranuclear gaze palsy. Repetitive Transcranial Magnetic Stimulation (rTMS) shows promising results when used as a therapeutic tool. We investigated the impact of cerebellar iTBS on Functional Connectivity (FC) in a group of PSP patients comparing Resting State fMRI, before and after iTBS treatment.We found a bilateral increase in FC in the caudate nucleus and in left parietal cortex, and a FC reduction in the right precuneus, after iTBS treatment. Our study provides new evidence that iTBS is able to induce modifications of FC in PSP patients.

 
2848.   6 Magnetisation Transfer Contrast to Enhance Detection of Neuromelanin Loss at 3T in Parkinson’s Disease.
Stefan T. Schwarz1, Nin Bajaj2, Paul S. Morgan3, Scott Reid4, Penelope A. Gowland5, and Dorothee P. Auer1
1Division of Radiological and Imaging Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Department of Neurology, Nottingham University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom, 3Medical Physics, Nottingham University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom, 4Clinical Science Development Group, GE Healthcare, Diagnostic Imaging, Hatfield, Hertfordshire, United Kingdom, 5School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

 
Parkinson’s disease (PD) is characterised by a progressive loss of pigmented neuromelanin containing dopaminergic neurons of the midbrain substantia nigra (SN). There is increasing evidence to suggest that specific T1 weighted MRI sequences with additional magnetisation transfer (MT) prepulses can be used to demonstrate neuromelanin pigment associated signal of the SN. The purpose of this study was to optimise previously published MRI protocols by investigating effects of ‘off-‘ and ‘on-resonance’ MT pulses on SN neuromelanin related MRI signal and on the signal reduction caused by neuromelanin depletion in PD. Robustness of protocols was assessed over different scanner platforms.

 
2849.   7 Detecting Alterations in Substantia Nigra in Parkinson’s Disease
Xiangchuan Chen1, Daniel Huddleston2,3, Jason Langley1, and Xiaoping P. Hu1
1Biomedical Imaging Technology Center, Emory University, Atlanta, GA, United States, 2Kaiser Permanente Center for Health Research Southeast, Atlanta, GA, United States, 3Department of Neurology, Emory University, Atlanta, GA, United States

 
Alterations in the substantia nigra (SN) in Parkinson’s disease (PD) were investigated with magnetic resonance imaging (MRI). By using a semi-automated approach, contrast-to-noise ratio and number of voxels of the SN were measured, which showed significant differences between a PD and a control group. These results suggest that loss of neuromelanin containing neurons, as occurs in PD, can be measured with this MRI approach. Moreover, these two MRI measures were significantly correlated with the orthostatic blood pressure drop, a phenotypic measure relevant to PD, implicating the role of SN in the pathophysiology of orthostatic hypotension in PD.

 
2850.   8 Frontal Lobe Dysfunction Correlates with Microstructural Alteration of Cerebral White Matter in Multiple System Atrophy. -permission withheld
Takaaki Hattori1, Kinya Ishikawa2, Kiyobumi Ota2, Shigeki Aoki3, Naoko Mitani4, and Hidehiro Mizusawa2
1NINDS, National Institute of Health, Chevy chase, MD, United States, 2Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Binkyo-ku, Tokyo, Japan, 3Radiology, Juntedo University, Bunkyo-ku, Tokyo, Japan, 4Otolaryngology, Kanto Central Hospital, Setagaya-ku, Tokyo, Japan

 
Pathology of multiple system atrophy (MSA) shows glial cell inclusions, predominantly found in the cerebral and cerebellar white matter. Although MSA patients complicate cognitive impairment, the underling substrates remain to be elucidated. Here, we aimed to elucidate the macro- and micro-structural alteration of brain and neuronal correlates of cognitive impairment in MSA patients by using voxel-based morphometry and diffusion tensor imaging. Out results suggest that there are localized white and grey matter atrophy as well as microstructural alteration in the broad white matter, and the frontal lobe dysfunction correlates with microstructural alteration of cerebral white matter in MSA patients.

 
2851.   9 Comparison of Brain Metabolite Changes in Manganese-Exposed Welders and Smelters
Zaiyang Long1,2, Yue-Ming Jiang3, Xiang-Rong Li4, Jun Xu1,2, Li-Ling Long4, Wei Zheng1, James B. Murdoch5, and Ulrike Dydak1,2
1School of Health Sciences, Purdue University, West Lafayette, Indiana, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Dept. of Occupational Health and Toxicology, Guangxi Medical University, Nanning, Guangxi, China,4Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China, 5Toshiba Medical Research Institute USA, Mayfair village, OH, United States

 
The aim of this study was to compare metabolite changes of welders and smelters following occupational manganese (Mn) exposure. Nine smelters, 14 welders and 23 controls were recruited. Short echo-time 1H spectra were acquired from frontal cortex, posterior cingulate cortex (PCC), hippocampus, and thalamus. Welders, with lower airborne Mn exposure, showed significantly decreased creatine (Cr) and glutamate (Glu) in the frontal cortex, and decreased myo-inositol (mI) in the PCC and in the hippocampus. Smelters showed decreased mI in the PCC and hippocampus, and increased Glu in the thalamus. Mn-induced brain metabolite changes seem regional and more extensive in welders.

 
2852.   10 Hemispheric Asymmetry of Hippocampus Perfusion and Its Response to Physostigmine Challenge in a Nationally Representative Sample of Gulf War Veterans
Xiufeng Li1,2, Jeffrey S. Spence3,4, David M. Buhner4, Robert W. Haley4, and Richard W. Briggs2,4
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Clinical Sciences, UT Southwestern Medical Center, Dallas, TX, United States, 4Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States

 
In previous ASL studies of Gulf War veterans from a Seabees battalion, the three major Haley syndrome groups of ill veterans had different patterns of laterality in hippocampus perfusion and in physostigmine-induced changes in hippocampus CBF, while healthy control veterans were absent laterality effects in hippocampus perfusion. This is now corroborated in a larger sample of veterans representative of all U.S. military personnel from the 1991 Persian Gulf War. The observed laterality of hippocampus perfusion at baseline and subsequent to cholinergic challenge with physostigmine and the differences in this laterality among ill syndrome groups may imply distinct pathological mechanisms of neurotoxic damage.

 
2853.   11 An Investigation of Functional Connectivity in the Inhibitory Control Network in Prodromal Huntington's Disease
Katherine A. Koenig1, Stephen M. Rao2, Mark J. Lowe1, Jian Lin1, Deborah L. Harrington3, Dawei Liu4, Ken E. Sakaie1, and Jane S. Paulsen5
1Imaging Sciences, Cleveland Clinic, Cleveland, OH, United States, 2Neurological Institute, Cleveland Clinic, Cleveland, Ohio, United States, 3Research, Neurology, and Radiology Services, Veterans Affairs San Diego Healthcare System, San Diego, CA, United States, 4Department of Biostatistics, The University of Iowa Carver College of Medicine, Iowa City, Iowa, United States, 5Department of Psychiatry, The University of Iowa Carver College of Medicine, Iowa City, Iowa, United States

 
The current study used a seed-based approach to examine resting state functional connectivity in the inhibitory control network in prodromal Huntington Disease. Our findings indicate that connectivity patterns are disrupted in the prodromal stages of HD, particularly to areas involved in task attention and motor intention.

 
2854.   12 Quantitative Susceptibility Mapping (QSM) in Wilsonprime or minutes Disease
Andreas Schäfer1, Dominik Fritzsch2, Peter Günther3, Robert Trampel1, Robert Turner1, and Karl-Titus Hoffmann2
1Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Department of Neuroradiology, University of Leipzig, Leipzig, Germany,3Department of Neurology, University of Leipzig, Leipzig, Germany

 
This study investigates whether copper accumulation in the brain of Wilson’s patients can be detected using QSM. We have measured 8 patients with Wilson’s disease and 10 age-matched healthy controls. Our data clearly show that the substantia nigra is more paramagnetic in Wilson’s disease patients compared to healthy controls. There is a trend that paramagnetic copper(II) induces the magnetic susceptibility changes in patients.

 
2855.   13 1H MRS Reveals Decreased Motor Cortex Glutathione in Patients with ALS
Nora Weiduschat1, Xiangling Mao1, Jonathan Hupf2, Nicole Armstrong2, Hiroshi Mitsumoto2, and Dikoma C. Shungu1
1Radiology, Weill Cornell Medical College, New York, NY, United States, 2Neurology, Columbia University College of Physicians and Surgeons, New York, NY, United States

 
Oxidative stress has been implicated in both sporadic and familial forms of amyotrophic lateral sclerosis (ALS), suggesting an inadequate antioxidant defense system, of which glutathione (GSH) is the most abundant and important component. While GSH deficiency has been documented and associated with cell pathology and survival in preclinical models of ALS, direct in vivo evidence in patients’ brain is lacking. In this study, 1H MRS was used to measure and compare in vivo levels of GSH in the motor cortex of ALS patients and matched healthy volunteers (HV), and found significant deficits of the antioxidant in the patient group.

 
2856.   14 Quantitative Susceptibility Mapping (QSM) of the Motor Cortex as a Potential Biomarker in Amyotrophic Lateral Sclerosis (ALS)
Tian Liu1,2, Andrew D. Schweitzer1, Karen S. Zheng1, Stephen Seedial1, Alexander Shtilbans3, Dale J. Lange3, Yi Wang1, and Apostolos John Tsirouis1
1Radiology, Weill Cornell Medical College, New York, New York, United States, 2MedImageMetric LLC, New York, New York, United States, 3Hospital for Special Surgery, New York, New York, United States

 
Amyotrophic lateral sclerosis (ALS) is an devastating disease yet there is currently no quantitative laboratory, imaging, or electrophysiological test that correlates with disease severity. In this study, we applied quantitative susceptibility mapping to ALS patients, and compared their susceptibility values in motor cortex to control subjects without ALS. Statistically significant increase in susceptibility was found in ALS patients, suggesting that QSM has the potential to be the first quantitative imaging biomarker for patients with ALS.

 
2857.   15 Assessing Regional Gray and White Matter Changes to Understand the CNS Related Symptoms of Myotonic Distrophy Type-1
Marco Bozzali1, Laura Serra2, Barbara Spanò2, Mario Torso2, L Lispi3, A Rosini3, S. Costanzi-Porrino3, M. Giacanelli3, Carlo Caltagirone4, and A Petrucci3
1Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, 2Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, 3Neurology and neurophysiopathology Unit, "San Camillo Forlanini" Hospital, Rome, Italy, 4Neurological and behavioural Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy

 
This voxel-based morphometry study investigates associations between regional grey (GM) and white matter (WM) volumes in patients with genetically confirmed Steinert disease (SD). Interesting associations between GM and WM atrophy, and clinical and neuropsychological features were found, which contribute to clarify some pathophysiological aspects of CNS involvement in SD.

 
2858.   
16 7T MRS Classification of Clinically Similar Ataxias (SCA1, SCA2, SCA3 and SCA6)
Uzay E. Emir1, Diane Hutter1, Khalaf O. Bushara1, Christopher M. Gomez2, Lynn E. Eberly1, and Gulin Oz1
1University of Minnesota, Minneapolis, MN, United States, 2University of Chicago, Chicago, IL, United States

 
Objective imaging markers that can differentiate genetic forms of spinocerebellar ataxias (SCAs) can help guide genetic testing for these neurodegenerative diseases. A prior MRS study suggested that neurochemical alterations can be utilized to differentiate SCA types. We measured neurochemical profiles in the cerebellum and brainstem of patients with SCA1, SCA2, SCA3, SCA6 and controls by 7T MRS. The patterns of neurochemical alterations differed between SCAs and lead to 88% accurate classification of all subjects (N=56), while the ataxia scores did not differ between patient groups. This study demonstrates the potential for MRS to classify neurodegenerative diseases with overlapping clinical presentation.

 
2859.   17 White Matter Abnormalities in Perinatally HIV-Infected Youths: A Diffusion Tensor Imaging Study
Manoj K. Sarma1, Margaret Keller2, Linda Chang3, Rajakumar Nagarajan1, Judy Hayes2, Karin Nielsen-Saines4, David E. Michalik5, Jaime Deville4, Joseph A. Church6, and M. Albert Thomas1
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, United States, 3Department of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, United States, 4Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, United States, 5Department of Infectious disease-Pediatrics, Miller’s Children’s Hospital of Long Beach, Long Beach, CA, United States, 6Department of Pediatrics, Children’s Hospital Los Angeles, Los Angeles, CA, United States

 
Neuropathological examinations show white matter (WM) involvement in the brains of HIV-infected patients. In this study we have compared diffusion tensor imaging (DTI) derived fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) across a group of perinatally HIV-infected youths and healthy controls. We performed structural DTI for six perinatally HIV-infected youths and five age-matched healthy controls. DTI analysis was done using the Large Deformation Diffeomorphic Metric Mapping (LDDMM) method. Our findings showed widespread brain regions of declined FA and increased AD values in perinatally HIV infected youths compared to healthy controls. Also we observed a trend of increasing MD and RD in HIV infected youths.

 
2860.   18 Whole-Brain MR Spectroscopic Imaging in Adults Perinatally-Infected with HIV
Varan Govind1, Anai Cuadra2, Elizabeth Willen2, Catherine Longa2, Kristopher Arheart3, M. Judy D. Post1, Monica Molina2, Carmen Velazquez2, Andrew A. Maudsley1, and Sulaiman Sheriff1
1Radiology, University of Miami, Miami, Florida, United States, 2Pediatrics, University of Miami, Miami, Florida, United States, 3Epidemiology, University of Miami, Miami, Florida, United States

 
The long term impact of HIV in the CNS and its antiretroviral treatment on proton MR-observed brain metabolites of adults perinatally-infected with HIV are not characterized completely. In this study, a unique whole-brain MRSI method is used to quantitate changes in brain metabolites, N-acetyl aspartate (NAA), total-creatine (Cre) and total-choline (Cho), in a group of adults perinatally-infected with HIV by comparing it to similar data from a matched community control group.

 
2861.   19 Dynamic Contrast Enhancement in a Mouse Model of Neuropsychiatric Systemic Lupus Erythematosus
Mark E. Wagshul1, Jing Wen2, Roman Fleysher3, Ariel Stock2, Craig A. Branch3, and Chaim Putterman4
1Radiology, Gruss MRRC, Albert Einstein College of Medicine, Bronx, NY, United States, 2Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, NY, United States, 3Radiology, Albert Einstein College of Medicine, Bronx, NY, United States, 4Medicine and Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, NY, United States

 
Neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the earliest manifestations in human lupus, and occurs in 60% of SLE patients. Major NPSLE symptoms in both human patients and in mouse models of the disease include mood disorders (especially depression) and cognitive dysfunction. However, the mechanisms of NPSLE are not fully understood. The purpose of this paper was to investigate early development of compromise of the blood brain barrier using dynamic contrast enhanced MRI in a mouse model of SLE. We show changes in gadolinium uptake in the hypothalamus as early as 9-10 weeks.

 
2862.   20 Assessment of Antiretroviral Therapy Effects in Early HIV Infection by Diffusion Tensor Imaging
Christina Louise Sammet1, Jordan S. Muraskin2, Riti J. Mahadevia1, Ying Wu3, Hongyan Du3, Leon Epstein1, Babafemi Taiwo1, and Ann B. Ragin1
1Northwestern University, Chicago, IL, United States, 2Columbia University, New York, NY, United States, 3NorthShore University Hospital, Evanston, IL, United States

 
Antiretroviral therapy (ART) has reduced AIDS-related deaths worldwide; however, neurocognitive impairment is evident in nearly 50% of patients receiving treatment. This may reflect limited penetration of ART through the blood brain barrier resulting in reduced treatment efficacy in the central nervous system. The neuroprotective benefit of ART, therefore, is not well characterized. Evidence suggests that some agents used in ART regimens may actually be neurotoxic. In order to assess the effects of treatment on the brain, this study used diffusion imaging to study treated and untreated HIV+ subjects and age matched controls.

 
2863.   21 Comprehensive Autoregional DTI and MTR of Asymptomatic HIV Brain
Ying Wu1,2, Ryan Hutten1, Yi Gao3, Hongyan Du3, Nadia Abbasi1, Robert R. Edelman1,4, and Ann B. Ragin4
1Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 2Department of Radiology, The University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 3Center for Clinical and Research Informatics (CCRI), NorthShore University HealthSystem, Evanston, IL, United States, 4Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States

 
We demonstrate the potential of an autoregional DTI and MTR framework as a sensitive strategy of brain assessment for preclinical populations. Compared to previous methods, this investigation addressed sensitivity and consistency through improved automation and comprehensive three dimensional standardized measurements of DTI and MTR. We found callosal abnormalities for both DTI and MTR in a cohort of asymptomatic HIV infection of less than one year. This autoregional framework holds promise as a sensitive tool for detecting early brain changes and monitoring disease progression.

 
2864.   22 Evidence for Structural Differences in Normal Appearing Brain Tissue of Those Carrying Different Alleles of APOE
Nicholas G. Dowell1, Simon L. Evans2, Torsten Ruest2, Paul S. Tofts1, Sarah L. King2, Naji Tabet3, and Jenny M. Rusted2
1CISC, Brighton and Sussex Medical School, Brighton, East Sussex, United Kingdom, 2School of Psychology, University of Sussex, Brighton, United Kingdom,3Brighton and Sussex Medical School, University of Brighton, Brighton, United Kingdom

 
Apolipoprotein E (APOE) is a protein involved in cholesterol and lipid transport. The gene coding for this protein has three different alleles: e2, e3 and e4. The e4 allele is recognized as a significant risk factor for developing Alzheimer’s disease in later life. Paradoxically, behavioural and functional evidence demonstrate the e4 allele may confer a cognitive advantage to the carrier in youth. We use qMT, DTI and VBM to identify subtle differences in the brain tissue of groups of young e4 and homozygous e3 carriers that might support that paradox.

 
2865.   23 CSF Biomarkers Associate with GM Volume and Brain Microstructural Changes Mainly from Default Mode Network in Alzheimer’s Disease
Xiaozhen Li1, Tie-Qiang Li2, Niels Andreasen3, Maria Kristoffersen Wiberg4, Eric Westman1, and Lars-Olof Wahlund1
1NVS Department, Karolinska Institutet, Stockholm, Stockholm, Sweden, 2Department of Medical Physics, Karolinska Institutet, Stockholm, Stockholm, Sweden, 3Alzheimer Disease Research Center, Karolinska Institutet, Stockholm, Stockholm, Sweden, 4Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm, Stockholm, Sweden

 
Alzheimer’s disease (AD) is the most common dementia in elderly people. The pathological hallmark of AD is amyloid plaques and neurofibrillary tangles, which are made up of Aβ42 and p-tau, respectively. Decreased levels of Aβ42 and increased levels of total tau protein (T-tau) and p-tau in CSF are useful and valid tool for the diagnosis and prognosis of AD. In this study, we investigated the correlation between AD CSF biomarkers and grey matter volume and brain microstructural changes using VBM analysis and DTI measurement.

 
2866.   24 A Preliminary Diffusional Kurtosis Imaging Study of Parkinson Disease: Comparison with Conventional Diffusion Tensor Imaging
Koji Kamagata1, Masaaki Hori1, Keigo Shimoji1, Michimasa Suzuki1, Atsushi Nakanishi1, Hiroyuki Tomiyama2, Yumiko Motoi2, Issei Fukunaga3, Humitaka Kumagai1, Nobutaka Hattori2, and Shigeki Aoki1
1Department of Radiology, Juntendo university, Tokyo, Japan, 2Department of Neurology, Juntendo university, Tokyo, Japan, 3Department of Radiology, Juntendo University, Tokyo, Japan

 
White matter abnormalities have been extensively investigated in Parkinson disease (PD). Diffusion tensor imaging (DTI) studies have reported diffusion abnormalities in the cerebral white matter in patients with PD, but these findings are controversial. The aims of this preliminary study were to investigate how the white matter is altered in PD as measured with DKI and to compare this to what is shown with DTI. DKI can detect changes in the cerebral white matter of PD patients more sensitively than conventional DTI. DKI may enable improved monitoring of disease progression and more effective treatment planning.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (11:45-12:45) Exhibition Hall
Advanced Imaging of Dementia

  Computer #  
2867.   1 Test-Retest Reliability of Brain Volume Measurements
Julian R. Maclaren1, Zhaoying Han1, Sjoerd B. Vos1,2, Christoph Seeger1,3, Alexander Brost1, Nancy J. Fischbein1, and Roland Bammer1
1Center for Quantitative Neuroimaging, Dept. of Radiology, Stanford University, Stanford, CA, United States, 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 3Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany

 
The monitoring of neurodegenerative disease progression may be assisted by quantitative measurement of the volume of structures in the human brain. We performed 120 scans on 3 volunteers over a period of 31 days. The resulting dataset is available online and is a valuable resource for quantifying the repeatability of brain volume measurements. Results show that lateral ventricle volume, in particular, varies significantly from day to day. This could potentially mask the effects of disease and should be taken into consideration in any analysis performed using ventricle volume.

 
2868.   2 Evolution of Hemispheric Asymmetry During Healthy Aging Revealed by Multivariate Analysis
Xiaojing Long1, Chunxiang Jiang1, Weiqi Liao1, and Lijuan Zhang1
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China

 
The hemispheric asymmetry of different age groups was measured using a multivariate model based on morphological variables to track the decennial evolution of cerebral laterality during healthy aging.

 
2869.   3 Comprehensive Autoregional and Autotract Based MTR Analysis of Alzheimer's Disease
Ryan Hutten1, Nadia Abbasi1, Michael Mercury2, Victoria Braund2, Zoran Grujic3, and Ying Wu1,4
1Department of Radiology, NorthShore University Health System, Evanston, IL, United States, 2Department of Psychiatry, NorthShore University Health System, Glenview, IL, United States, 3Department of Internal Medicine, University of Chicago Pritzker School of Medicine, Chicago, IL, United States,4Department of Radiology, The University of Chicago Pritzker School of Medicine, Chicago, IL, United States

 
Previous imaging studies of Alzheimer's disease have shown regional abnormalities in patients using both diffusion tensor imaging (DTI) and magnetization transfer ratio (MTR). We build upon the work of previous studies by combining two commonly used methods into one automated process. In this study, we utilize an autoregional method to isolate specific brain regions, and then perform an autotractography algorithm to target white matter tracts associated with the included brain regions. This procedure detects previously unseen MTR differences between the white matter fiber tracts of AD patients and healthy controls.

 
2870.   4 Mapping the Alzheimer’s Structural Connectome: Findings from the Alzheimer Disease Neuroimaging Initiative -permission withheld
Jeffrey William Prescott1, Arnaud Guidon2, Chunlei Liu2, Allen Song2, Murali Doraiswamy3, Jeffrey Petrella1, and for the Alzheimer’s Disease Neuroimaging Initiative1
1Radiology, Duke University, Durham, NC, United States, 2Brain Imaging Analysis Center, Duke University, Durham, NC, United States, 3Psychiatry & Behavioral Sciences, Duke University, Durham, NC, United States

 
The current analysis was designed to evaluate changes in the structural connections in the brain, as assessed by connectome mapping from diffusion tensor imaging (DTI) MR scans, among normal controls (NC), subjects with mild cognitive impairment (MCI), and subjects with AD in the Alzheimer's Disease Neuroimaging Intiative 2 (ADNI2). There were 101 ADNI2 subjects in the analysis. The bilateral insula weighted degree were significantly associated clinical diagnosis.

 
2871.   5 Relationship Between Cardiovascular Health, Cerebral Physiology and Cognition in Healthy Aging
Claudine Joëlle Gauthier1, Muriel Lefort2, Saïd Mekary3, Laurence Desjardins-Crépeau3, Cécile Madjar3, Louis Bherer4, Frédérique Frouin2, and Richard D. Hoge5
1Neurophysics, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Saxony, Germany, 2Inserm 678, UPMC, CHU Pitié Salpêtrière, Paris, Ile-de-France, France, 3CRIUGM, Montreal, Quebec, Canada, 4Concordia University, Montreal, Quebec, Canada, 5Physiology, CRIUGM/Université de Montréal, Montreal, Quebec, Canada

 
Arteries throughout the body stiffen with age, but vessel hardening may start at the level of the aorta and progress to other organs, including the brain. Vascular impairment may contribute to cognitive changes observed with aging. Furthermore, it may be that regular exercise acts as a modulator to partially attenuate the effects of age on vascular and metabolic physiology. Here we show imaging results indicative of a link between vascular health at the level of the aorta, the carotids and the brain with measures of cardiovascular fitness and cognition.

 
2872.   6 Age-Dependence of Hemodynamic Response Characteristics in Human FMRI
Claudine Joëlle Gauthier1,2, Cécile Madjar3,4, Laurence Desjardins-Crépeau3,5, Pierre Bellec3,6, Louis Bherer3,7, and Richard D. Hoge2
1Neurophysics, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Saxony, Germany, 2Physiology, CRIUGM/Université de Montréal, Montreal, Quebec, Canada, 3CRIUGM, Montreal, Quebec, Canada, 4Montreal Neurological Institute, Montreal, Quebec, Canada, 5Psychology, UQAM, Montreal, Quebec, Canada, 6Computer Science and Operations Research, Université de Montréal, Montreal, Quebec, Canada, 7Concordia University, Montreal, Quebec, Canada

 
The BOLD signal is often used as a direct index of neuronal activity to study changes with aging. However, profound changes in cerebrovascular properties in older adults may lead to biases in the interpretation of BOLD signal differences between young and old. Here we show that changes in baseline blood flow, reactivity to hypercapnia and calibration parameter M are present even in healthy aging. These changes may lead to underestimation of metabolic changes with aging.

 
2873.   7 Reproducibility of Brain Morphometry Results Derived at 3T: A Multi-Center European Study Comparing the Longitudinal and Cross-Sectional Freesurfer Segmentation Analyses
Jorge Jovicich1, Moira Marizzoni2, Roser Sala-Llonch3, Nuria Bargalló3, David Bartrés-Faz3, Jennifer Arnold4, Jens Benninghoff4, Jens Wiltfang4, Luca Roccatagliata5, Flavio Nobili5, Christian Zeeh6, Peter Schonknecht6, Giada Zoccatelli7, Franco Alessandrini7, Alberto Beltramello7, Hélène Gros-Dagnac8, Pierre Payoux8, Valérie Chanoine9,10, Jean-Philippe Ranjeva9,10, Mira Didic9,10, Melanie Leroy11, Regis Bordet11, and Giovanni Frisoni2
1University of Trento, Center for Mind/Brain Sciences, Mattarello, Trento, Italy, 2IRCCS San Giovanni di Dio Fatebenefratelli, LENITEM Lab of Epidem., Neuroim. & Telem, Brescia, Lombardia, Italy, 3Dept. Psychiatry and Clinical Psychobiology, Faculty of Medicine University of Barcelona, Barcelona, Barcelona, Spain, 4Department of Psychiatry and nuclear medicine, Universitaet Duisburg-Essen, Essen, Essen, Germany, 5Dept of Neuroscience, Ophthalmology and Genetics, University of Genoa, Genoa, Lombardia, Italy, 6Dept of Psychiatry and Dept of Neuroradiology, University of Leipzig, Leipzig, Leipzig, Germany, 7Dept of Neuroradiology, Verona General Hospital, Verona, Verona, Italy, 8U825 - Plateau Technique IRM, INSERM / Université Paul Sabatier, Toulouse, Toulouse, France, 9Hôpital La Timone CIC – UPCET, Marseille, Marseille, France, 10Centre de Resonance Magnetique Biologique et Medicale, Aix Marseille Université, Marseille, Marseille, France, 11Universitè Lille UL2, Lille, Lille, France

 
The success in finding clinically useful MRI-derived biomarkers is highly dependent on data acquisition and analysis strategies. In this brain morphometry study we show for the first time the across-session test-retest reproducibility advantages of the fully automated longitudinal FreeSurfer segmentation protocol relative to the cross-sectional analysis, when tested in a consortia using different 3T MRI scanners (Siemens, Philips, GE) acquiring standard 3D MPRAGE data, with 7 out of 8 sites using parallel imaging acquisition (about 5 min acquisition per volume) and no data averaging.

 
2874.   8 Tissue Cell Fraction (TCF) from Quantitative Sodium MR Imaging Does Not Change with Age in Cognitively Normal Subjects
Keith R. Thulborn1, Saad Jamil1, Aiming Lu1, and Ian C. Atkinson1
1Ctr Magnetic Resonance Research, University of Illinois, Chicago, IL, United States

 
Quantitative sodium MR imaging at 9.4 Tesla has been used to measure cell density in the brain of cognitively normal individuals (N=14) across the adult age range (20-65 years). Despite the known ongoing tissue loss with aging, the constant cell density suggests that this is a highly conserved structural parameter. The brain must shrink with age as cells are lost in order to preserve cell density and hence function. This may be related to the need to maintain the intra- and extra-cellular volumes to preserve the resting membrane potential at the same energy demand of the Na/K ion pumps.

 
2875.   9 T1rho Measurement in Rat Brain Tissue Changes Associated with Aging and Chronic Hypertension
Feng Zhao1, Li-Hong Zhang2, Jing Yuan1, Queenie Chan3, David Yew2, and Yi-Xiang Wang1
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, 2Brain Research Centre, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, 3Philips Healthcare, Hong Kong, Hong Kong

 
T1rho relaxation has been suggested as a sensitive biomarker to detect Alzheimer¡¯s disease and Parkinson¡¯s disease. Aging and hypertension are two major risk factors for common neurodegenerative diseases. Spontaneously hypertensive rat (SHR) is most extensively investigated for evaluating hypertensive brain damage. In this study, the T1rho values in thalamus, hippocampus and cortices of SHR and WKY control rats at the age of 6, 9 and 12-month were measured longitudinally. T1rho values in these regions of SHR were consistently higher than those in WKY rats. Meanwhile, the regional brain T1rho values of both SHR and WKY rats increased with aging process.

 
2876.   10 Voxel-Based Analysis of Cerebral Perfusion Changes in Alzheimer Disease and Mild Cognitive Impairment Measured with a Novel 3D Arterial Spin Labeling Technique
Yong Zhang1, He Wang1, Guang Cao1, Qing Mao1, Bei Ding2, and Hua-Wei Ling2
1GE Healthcare, Shanghai, Shanghai, China, 2Ruijin Hospital, Shanghai, Shanghai, China

 
This preliminary study investigated cerebral perfusion changes in Alzheimer¡¯s disease (AD) and mild cognitive impairment (MCI) measured with a novel 3D arterial spin labeling technique to facilitate more accurate voxel-wise comparison. Twenty-four AD patients, seventeen MCI patients and twenty-one healthy controls were recruited. In addition to the decreased CBF regions in the bilateral temporo-parieto-occipital cortex, increased CBF was observed in bilateral thalamus, right temporal lobe and paracentral lobule for AD patients and in bilateral frontal lobes and right temporal lobe for MCI patients. Our results suggested the existence of the different patterns of hyperperfusion along with the disease evolvement.

 
2877.   11 An Integrated Resting-State fMRI and DTI Based Connectivity Analysis to Understand Brain Alteration Affected by Alzheimer’s Disease and Amnestic Mild Cognitive Impairment
Shantanu Majumdar1 and David C. Zhu1,2
1Department of Radiology, Michigan State University, East Lansing, MI, United States, 2Department of Psychology, Michigan State University, East Lansing, MI, United States

 
Integration of resting-state functional connectivity analysis with the DTI based white matter connectivity analysis can provide overall neuronal connectivity information about the regions of interest involved. In Alzheimer’s disease (AD) and amestic mild cognitive impairment patients, certain specific brain regions are affected at early stages than other regions. In this work, we present a quantitative analysis of combined functional-structural connectivity to study the changes in certain cortical regions of the brain known to be affected in AD.

 
2878.   12 Regional Brain Stiffness Changes Across the Alzheimer's Disease Spectrum
Matthew C. Murphy1, John Huston1, Clifford R. Jack1, Kevin J. Glaser1, David T. Jones2, Matthew L. Senjem1, Armando Manduca3, Joel P. Felmlee1, and Richard Leroy Ehman1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, 2Department of Neurology, Mayo Clinic, Rochester, MN, United States, 3Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States

 
Building on a previous finding that global brain stiffness is a novel biomarker of Alzheimer’s disease (AD), the purpose of this work was to measure regional brain stiffness across the full AD spectrum (i.e. cognitively normal → mild cognitive impairment → AD dementia). Using a novel MR elastography pipeline, this work demonstrates that changes in brain stiffness follow the known topography of AD (frontal, parietal and temporal lobes significantly affected). Furthermore, brain stiffness may provide unique insights into the temporal dynamics of AD progression as it was shown to change non-monotonically with respect to disease severity.

 
2879.   13 ex-vivo MRI Detects T2 Alterations Associated with Alzheimer’s Disease, Comorbid Neuropathology, and Antemortem Cognition
Robert Dawe1, David A. Bennett1, Julie Schneider1, Sue Leurgans1, and Konstantinos Arfanakis1,2
1Rush University Medical Center, Chicago, IL, United States, 2Illinois Institute of Technology, Chicago, IL, United States

 
The transverse relaxation time constant T2 carries potentially valuable information regarding the condition of brain tissue. Postmortem T2 maps from 211 elderly human brain hemispheres were spatially normalized and voxelwise analysis of covariance (VANCOVA) was carried out, with histopathologic observations serving as explanatory variables. This analysis revealed significant associations between regionally prolonged T2 values and histopathologically confirmed Alzheimer’s disease, as well as gross infarcts. An additional VANCOVA showed that T2 in white matter of the frontal lobe can account for approximately 10% of the cross-sectional variance in semantic and working memory.

 
2880.   14 Sensitivity of Brain Volumetry: A FreeSurfer-Based Segmentation Study of Brain Data Acquired with the ADNI Protocol Vs. GE BRAVO
Zhaoying Han1, Julian R. Maclaren1, Alexander Brost1, Sjoerd B. Vos1,2, Christoph Seeger1,3, Nancy J. Fischbein1, and Roland Bammer1
1Center for Quantitative Neuroimaging, Department of Radiology, Stanford University, Palo Alto, CA, United States, 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 3Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany

 
Biomarkers for neurodegenerative diseases derived from MRI brain structures are promising to translate into clinical practice by comparing a patient’s brain to those in a database. The aim of this study was to choose the well-defined standard protocol from the ADNI project and compare it to the standard GE BRAVO sequence used in clinical routine at our institution and assess comparability of volumetric measurements. Statistical analysis shows that ADNI and our clinical BRAVO protocol – although tightly matched in terms of scan parameters – have statistically significant differences in estimated volumes of the lateral ventricles and hippocampus with Freesurfer segmentations.

 
2881.   15 Age-Related Changes in Regional Brain T1 and T2 Relaxation Times in the Healthy Mouse at 17.6 T
Firat Kara1, Fu Chen1, Itamar Ronen2, Huub J. M. de Groot1, Jorg Matysik1,3, and A Alia1,2
1Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands, 2Department of Radiology, Leiden University Medical Center, Leiden, Netherlands,3Institut fuer Analytische Chemie, Universitaet Leipzig, Leipzig, Germany

 
The estimates of in vivo T2 and T1 at 17.6 T will be useful to optimize pulse sequences for optimal image contrast and will serve as baseline values against which disease-related relaxation changes can be assessed in mice. This study establishes for the first time the normative T2 and T1 values at 17.6 T over different mouse brain regions with age. T2 values at 17.6 T typically increased with age in multiple brain regions except in the hypothalamus and the caudate-putamen, where a slight decrease was observed. Furthermore, T1 values in various brain regions of young and old mice are presented at 17.6 T.

 
2882.   16 2D L-COSY MR Spectroscopy Detects Changes in Brain Glucose Level in a Mouse Model of Alzheimer's Disease
A Alia1,2, Firat Kara1, Niels Braakman1, Mark A. van Buchem2, and Reinhard Schliebs3
1Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands, 2Department of Radiology, Leiden University Medical Center, Leiden, Netherlands,3University of Leipzig, Leipzig, Germany

 
Alzheimer’s disease (AD) is the most common neurodegerative disease afflicting mainly the elderly. Glucose metabolism and uptake has been shown to be impaired during AD which is proposed to be an important cause of neurodegeneration. However the cause of impairment of glucose uptake/metabolism in AD brain and its correlation with plaque deposition is not clear. The aim of this study is to investigate regional brain glucose levels changes with age using two dimensional correlated MR spectroscopy (L-COSY) at 9.4 T. Our results indicate that age dependent decline in glucose level occur primarily in plaque affected areas of TG2576 mice.

 
2883.   17 Comparing Differences in Alzheimer's Disease Classification Between Structural and Resting-State Functional MRI Biomarkers
Guangyu Chen1, Chunming Xie1, Guangyu Chen1, Wenjun Li1, B. Douglas Ward1, Jennifer L. Jones2, Malgorzata Franczak2, Piero G. Antuono2, and Shi-Jiang Li1
1Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States

 
Data from 65 Alzheimer's disease and 136 cognitively normal subjects were included in the study. We compared Alzheimer's disease classification techniques, using structural and resting-state functional MRI biomarkers. When the RfMRI classification result agreed with the structural MRI classification result, the subjects were classified with 90% accuracy. The incongruous classification results may predict disease conversion or treatment response.

 
2884.   18 Quantitative Susceptibility Mapping (QSM) in Alzheimerprime or minutes Disease - A Postmortem Study
Andreas Schäfer1, Solveig Tiepolt2, Elisabeth Roggenhofer1, Robert Trampel1, Carsten Stueber1, Vilia Zeisig2, Udo Grossmann2, Thies H. Jochimsen2, Osama Sabri2, Robert Turner1, and Henryk Barthel2
1Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany

 
In Alzheimer’s disease (AD) iron is accumulated in regions with beta-amyloid plaques. The aim of this study is to investigate whether a difference in quantitative magnetic susceptibility values in gray matter between postmortem tissue samples of AD patients and healthy controls can be detected using magnetic resonance imaging, via the high sensitivity of quantitative susceptibility mapping (QSM) to iron content. We have measured a significant susceptibility difference in the GM between beta-amyloid-positive AD and beta-amyloid-negative control tissue, with higher values for the AD tissue.

 
2885.   19 Gender-Specific Anatomical Alterations of Hemispheric Asymmetry During Healthy Aging of Human Brain
Xiaojing Long1, Chunxiang Jiang1, Weiqi Liao1, and Lijuan Zhang1
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China

 
A multivariate model based on morphological variates including cortical surface area, curvature index, thickness, and subjacent white matter volume, was developed to evaluate and track the differences of laterality alterations between male and female genders during healthy aging.

 
2886.   20 Comparison of Neuroimaging Biomarkers in Alzheimer’s Disease
Pablo Garcia-Polo1,2, Daniel Garcia-Frank3, Alicia Quiros4, Zhongmin Lin5, Litao Yan5, Gopal Avinash5, Roberto Garcia-Alvarez6, Juan Álvarez-Linera7, and Juan Antonio Hernandez-Tamames1,2
1DTE, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain, 2CIBERNED, Alzheimer's Project Queen Sofia Foundation, Madrid, Madrid, Spain, 3IDIPAZ, FIBHULP, Madrid, Madrid, Spain, 4Universidad Rey Juan Carlos, Fuenlabrada, Madrid, Spain, 5GE Healthcare, Waukesha, WI, United States, 6GE Healthcare, Madrid, Madrid, Spain, 7Hospital Ruber Internacional, Madrid, Madrid, Spain

 
This piece of work compares structural, metabolic and physiological biomarkers in order to characterize the Alzheimer’s disease, which is the most common cause of dementia, with neuroimaging methods. This study asks which biomarkers, or a combination of them, provide the most complete picture of the brain alterations in this pathology.

 
2887.   21 Neural Correlates of Constructional Apraxia in Patients with Alzheimer’s Disease.
Laura Serra1, Lucia Fadda2, Roberta Perri2, Barbara Spanò1, Mario Torso1, Diana Castelli3, Camillo Marra3, Carlo Caltagirone2, and Marco Bozzali4
1Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy, 2Neurological and behavioural laboratory, IRCCS Santa Lucia Foundation, Rome, Italy,3Institute of Neurology, Università Cattolica, Roma, Italy, 4Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy

 
Using voxel-based morphometry we investigated the pathophysioological substrate of constructive apraxia (CA) in patients Alzheimer's disease (AD). A peculiar pattern of regional GM atrophy was present in those patients with CA manifestations but not in the others. Our findings fit well with current anatomo-functional theories on CA.

 
2888.   22 Impact of Short-Term Administration of Oral Minocycline, a Repurposed Anti-Neuroinflammatory Agent, on MR and Neuropsychological Biomarkers of MCI and AD
Thao T. Tran1, Cherise Charleswell1, Nick O'Dell1, June Liu1, Michael Miller2, Michael Lindsey3, and Brian D. Ross1
1Clinical MR, HMRI, Pasadena, CA, United States, 2Webster's Community Pharmacy, Altadena, CA, United States, 3Huntington Memorial Hospital, Pasadena, CA, United States

 
We demonstrate the impact of minocycline on mild cognitive impairment (MCI) and Alzheimer's disease (AD) by employing quantified MR neuro-imaging (qMRI) and neurospectroscopy (MRS).

 
2889.   23 Iron-Related Microstructural Alterations in Deep Gray Matter: Correlations from Diffusional Kurtosis Imaging and Quantitative Susceptibility Mapping
Nan-Jie Gong1, Chun-Sing Wong1, Chun-Chung Chan2, Lam-Ming Leung2, and Queenie Chan3
1Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China, 2United Christian Hospital, Hong Kong, China, 3Philips Healthcare, Hong Kong, China

 
Using both quantitative susceptibility mapping (QSM) and diffusional kurtosis imaging (DKI) methods, we investigated age-related iron depositions in subcortical gray matters of globus pallidus (GP) and putamen (Pu). Besides, the contribution of iron deposition with aging to microstructural alterations in deep gray matter has also been studied by testing correlations between DKI parameters and susceptibility.

 
2890.   24 Investigation of Functional Connectivity Changes in Alzheimer Disease Using Degree Centrality
Yong Zhang1, He Wang1, Guang Cao1, Lin Zhang2, and Gui-Xiang Zhang2
1GE Healthcare, Shanghai, Shanghai, China, 2Shanghai First People's Hospital, Shanghai, Shanghai, China

 
This preliminary study investigated functional connectivity changes in Alzheimer¡¯s Disease (AD) using degree centrality (DC), a novel resting-state fMRI parameter to provide voxel-wise whole brain functional connectivity measurement. Six AD patients and nine age- and gender-matched healthy controls were recruited for comparison. In additional to the deceased DC regions in bilateral hippocampus and frontal lobe observed for normal aging controls and AD patients, the right insular showed increased DC for normal controls but decreased DC for AD patients, which might provide interesting insight into the mechanism of the disease.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (10:45-11:45) Exhibition Hall
Advanced Neuroimaging: Traumatic Brain Injury & Other Clinical Applications
  Computer #  
2891.   25 WITHDRAWN
 
2892.   
26 1H MRS Suggests Chronic and Acute Injury in High School Football Players
Victoria N. Poole1, Larry Leverenz2, Eric Nauman1,3, Thomas Talavage1,4, and Ulrike Dydak5,6
1School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States, 3School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States, 4School of Electrical Engineering, Purdue University, West Lafayette, IN, United States, 5School of Health Sciences, Purdue University, West Lafayette, IN, United States, 6Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, United States

 
To assess the consequence of repetitive hits on neural metabolism, proton magnetic resonance spectroscopy has been performed in high school American football athletes prior, during, and after their competition season. Our results in the dorsolateral prefrontal cortex, primary motor cortex, and cerebellum show that these contact sport athletes exhibit significant deviations in season from their pre-season scans that are consistent with glial cell damage and compromised functionality. When the pre-season measures are compared with preliminary data from non-contact athletes serving as controls, the data suggest the contact athletes began the season with incomplete recovery and, quite possibly, have chronic damage.

 
2893.   27 1H Metabolite Level Changes in Certain Brain Structures During Mild Traumatic Brain Injury
Michal Bittsansky1, Stefan Sivak1, Jan Grossmann1, Veronika Ilovska1, Petra Hnilicova1, Egon Kurca1, and Dusan Dobrota1
1Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia, Slovakia

 
In patients with mild traumatic brain injury (mTBI), our aim was to find correlations between clinical scores and proton metabolite concentrations in different parts of the brain. 21 patients within 2-3 days after injury and 21 matched volunteers were examined with cognitive tests, MR spectroscopic imaging (CSI) and single-voxel spectroscopy. NAA in lateral frontal areas was decreased in all patients, in brain stem only in the individuals with unconsciousness. Significant positive correlations of frontal lateral NAA with cognitive test results were observed. CSI revealed further spatial metabolite information. Our results help resolve the involvement of different brain parts during mTBI.

 
2894.   28 DTI Abnormalities Following Blast-Related TBI Across 4 Independent Cohorts: Regional Specificity for the Middle Cerebellar Peduncle
Christine MacDonald1, Ann Johnson1, Octavian Adam2, Dennis Rivet2, James Sorrell1, Brian Sammons1, Dana Cooper1, Linda Wierzechowski3, Yolanda Barnes3, John Ritter4, Todd May5, Maria Barefield2, Josh Duckworth2, Don Labarge2, Dean Asher2, Benjamin Drinkwine2, Joshua S. Shimony6, Matthew Parsons7, Abraham Snyder6, Michael Russell8, John Witherow3, Raymond Fang3, Stephen Flaherty3, and David L. Brody9
1Neurology, Washington University, Saint Louis, MO, United States, 2NATO Role 3 Kandahar Air Field, Kandahar, Afghanistan, 3Landstuhl Regional Medical Center, Landstuhl, Germany, 4Bastion Hospital, Helmond Province, Afghanistan, 5Camp Leatherneck, Helmond Province, Afghanistan, 6Radiology, Washington University, Saint Louis, MO, United States, 7Radiology, Washington University, Saint Louis, Missouri, United States, 8US Army, San Antonio, TX, United States, 9Neurology, Washington University in St. Louis, Saint Louis, MO, United States

 
Blast-related traumatic brain injury (TBI) has been called the ‘signature injury’ of the wars in Iraq and Afghanistan. In the current study, 4 independent cohorts of individuals exposed to blast were studied with diffusion tensor imaging. These cohorts provided a unique opportunity to compare and contrast imaging findings across patients following blast exposure at varying time points post injury; potentially documenting the temporal evolution of this injury. Although each cohort identified regions of reduced anisotropy indicative of white matter injury, only the left middle cerebellar peduncle was found to be abnormal across all 4 cohorts.

 
2895.   29 Long-Term Impact of Major Trauma on Brain Network Function in Traumatic Survivors
Mingying Du1, Wei Liao2, Su Lui1, Xiaoqi Huang1, and Qiyong Gong1
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China, 2Central for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, Zhejiang, China

 
Evidences had showed acute impact on the brain activity and functional connectivity in healthy trauma survivors, however, little is known about the long-term impact of trauma on the brain network function of healthy survivors. The aim of current study was to use graph theory analysis to evaluate the alteration of neural network function in survivors 2-year after trauma comparing with healthy controls without traumatic experience. Our results provide evidence that the major trauma has long-term impact on the brain network function in physically healthy survivors, highlighting the need for long-term evaluation and intervention for trauma survivors.

 
2896.   30 Global Diffusion Kurtosis Parameter Changes in Mild Traumatic Brain Injury Patients with Persistent Symptoms at Six Months
Jiachen Zhuo1, Teodora Stoica1, Steven Roys1, Chandler Sours1,2, Kathirkamanthan Shanmuganathan1, and Rao P. Gullapalli1
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, 2Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States

 
Patients with mild traumatic-brain-injury (mTBI) pose a special challenge as often the radiological diagnosis may underrepresent the true clinical condition of the patient. In this study, we use diffusion-kurtosis-imaging to study global white and gray matter changes following mTBI at sub-acute and chronic stages and examine their relationship to patients symptoms and cognitive status. mTBI patients with persistent post concussive symptoms showed greater changes in global tissue microstructures. Such changes persist into the chronic stage even when their cognitive performance has recovered. DKI parameters are sensitive to gray matter changes and myelin integrity hence may complement DTI in evaluating mTBI.

 
2897.   31 Improving the Reliability of Between Group Analyses in DTI-FA Analyses by Detecting and Removing Anatomical Anomalies
Ramtilak Gattu1, Zhifeng Kou2, Robert Welch3, Valerie Mika4, Hardik Doshi4, Ewart Mark Haacke2, and Randall Benson5
1Radiology, Wayne State University, Detroit, Michigan, United States, 2Biomedical Engineering, Radiology, Wayne State University, Detroit, Michigan, United States, 3Emergency Medicine, Wayne State University School of Medicine, Detroit, Michigan, United States, 4Biomedical Engineering, Wayne State University, Detroit, Michigan, United States, 5Center for Neurological Studies, Novi, Michigan, United States

 
A method of removing anomalous anatomy is described to be applied to diffusion tensor image processing involving between subject comparison. The method first attempts to spatially register all images into a common space but in some cases the registration is strained by anatomical anomalies which would result in artifactual results if not accounted for. The method described utilizes sampled voxelwise FA variance from controls in order to exclude or mask outlier values over spatial scales consistent with anatomical anomalies. The results reported indicated the value of the method in reducing false positive artifacts in DTI analysis.

 
2898.   32 Serial Atlas-Based DTI Study of Mild Traumatic Brain Injury in Adults
Khader M. Hasan1, Terrell D. Staewen1, Elisabeth A. Wilde2, Emmy R. Miller3, Melisa Frisby2, James J. McCarthy4, Jill V. Hunter5, Harvey S. Levin2, Claudia S. Peterson3, and Ponnada A. Narayana1
1Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, Texas, United States, 2Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas, United States, 3Neurosurgery, Baylor College of Medicine, Houston, Texas, United States,4Emergency Medicine, University of Texas Health Science Center at Houston, Houston, Texas, United States, 5Pediatric Radiology, Texas Children's Hospital, Houston, Texas, United States

 
In this report, we applied DTI methods serially on cohorts of healthy orthopedic controls and mTBI to characterize regional and global macrostructural and microstructural attributes of white matter, gray matter and cerebrospinal fluid to identify and differentiate patterns of acute and short-term recovery trends. Given that some previous DTI reports on mTBI in adults implicated the left anterior corona radiata, we analyzed this entire zone using atlas-based methods. Our analysis of the cross-sectional and serial data demonstrates dissociation between volumetric (macrostructural) and tissue integrity (microstructural) attributes and show the potential utility of DTI to capture a pattern of transient vasogenic edema using the DTI measurements of the corona radiata.

 
2899.   33 Identification of Mild Traumatic Brain Injuries by Comparison of Free-Water Corrected Z-Distributions
Ofer Pasternak1, Sylvain Bouix1, Yogesh Rathi1, Craig A. Branch2, Carl-Fredrik Westin1, Martha E. Shenton1,3, and Michael L. Lipton2
1Harvard Medical School, Boston, Massachusetts, United States, 2The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, United States, 3VA Boston Healthcare System, Brockton, MA, United States

 
Detection of brain abnormalities following mild traumatic brain injury (mTBI) is hard since tissue changes are subtle and heterogeneously located, thus not well suited to be detected using group analyses. We study a diagnosis approach in which free-water corrected diffusion MRIs of acute mTBI subjects are individually compared to a normative atlas. By analyzing the distribution of z-scores we are able to demonstrate significant group differences, which were not detected using conventional group analyses. We locate ranges in the distribution that are most specific to the injury, and these infer the types of abnormalities that can be expected in mTBI,

 
2900.   34 Functional and Structural Correlation of Hemispheric Language Lateralization Assessed by Functional MRI, Diffusion Tensor Imaging and Voxel Based Morphometry
Chandrasekharan Kesavadas1, Jija S. James, Bejoy Thomas, T. R. Kapilamoorthy, and Sankara Sarma
1Radiology, SCTIMST, Trivandrum, Kerala, India

 
A combination of functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI) and Voxel Based Morphometry (VBM) used together can give better information of the language lateralization than using a single technique alone.The combination of these three techniques provides an opportunity to study the relationship between brain structure and function. In patients especially small children who fail to perform the fMRI language tasks, the presurgical lateralization of language function may be done using diffusion tractography & volumetry of specific cortical structures.

 
2901.   35 Preliminary Cognitive Functional Imaging Study of Patients with Early Diabetes -permission withheld
Wei Tian1, Xiang Liu1, Jianhui Zhong1, and Sven Ekholm1
1Imaging Sciences, University of Rochester Medical Center, Rochester, NY, United States

 
There are few studies about cognitive functional imaging study in early diabetes Our study analyzed 20 patients with early type 2 diabetes mellitus and 15 demographically similar, healthy subjects. The microalbuminuria, hypoglycemia and ketonic acidosis, cerebral lesions were ruled out. A series psychological tests, nback task fMRI and single-voxel MRS with TE 30 on bilateral PFC were performed on both groups. Our results show decreased cognitive test scores and less activation especially on PFC in patient group. Increase of Glx and decrease of Cho could be detected, p<0.01; while there was no significant change of NAA. Transit memory was negatively correlated with Glx/Cho (F=-0.546, P value =0.013) and Glx/(Cr+Cho) (F=-0.471, P value = 0.036). The number of errors in trail making test A was positively related to NAA/Cr. Our study revealed cognitive dysfunction in early type 2 diabetic patients. The hypofunction in PFC plays an important role in cognitive dysfunction and the emotional abnormality. Increase of Glx and the degeneration of choline neuron system, which maybe contribute to the pathophysiological basis of PFC hypofunction.

 
2902.   36 Myelin Water Fraction Measurement Using Free Induction Decay and Refocused Gradient Echoes
Wendy W. Ni1,2, Thomas Christen1, and Greg Zaharchuk1
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Department of Electrical Engineering, Stanford University, Stanford, CA, United States

 
In this study, we demonstrate the feasibility of a novel myelin water fraction (MWF) measurement method that utilizes free induction decay (FID) and post-spin echo refocused gradient echoes acquired with the Gradient-Echo Sampling of FID and Echo (GESFIDE) sequence. Preliminary results are mostly consistent with literature values of MWF in several regions of interest. While the method needs further improvement of the signal model and optimization of imaging parameters, it demonstrates great potential for examining myelination state in the human brain.

 
2903.   37 Subcortical Brain Segmentation of Two-Dimensional T1w Data Sets with FIRST -permission withheld
Michael Amann1, Michaela Andelova2, Nicole Mueller-Lenke3,4, Julia Reinhardt3, Stefano Magon2,4, Stefan Traud4, Katrin Weier2, Ludwig Kappos2, Ernst-Wilhelm Radue4, Christoph Stippich3, and Till Sprenger2
1Neurology/Neuroradiology, Universitätsspital Basel, Basel, BS, Switzerland, 2Neurology, Universitätsspital Basel, Basel, BS, Switzerland, 3Neuroradiology, Universitätsspital Basel, Basel, BS, Switzerland, 4Medical Image Analysis Centre, Basel, BS, Switzerland

 
We investigated the feasibility of FIRST deep grey matter (DGM) segmentation of interpolated 2D T1w data sets by comparing the results with the respective segmentation of 3D data. 30 patients were included in this study. The MR scanning protocol included two T1-weighted scans: an isotropic 3D MPRAGE sequence and a 2D T1w-SE sequence. The 2D data were sinc-interpolated to an isotropic resolution of 1mm3. Then, both interpolated 2D data and 3D data were processed using FIRST. Intra-class correlation coefficients were calculated. Strong agreement was found between total DGM volumes and also for the larger subcortical structures.

 
2904.   38 Exploring Anterioposterior Differences of Hippocampus Perfusion Response to Physostigmine Using ASL
Xiufeng Li1,2, Jeffrey S. Spence3,4, David M. Buhner4, Robert W. Haley4, and Richard W. Briggs2,4
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Clinical Sciences, UT Southwestern Medical Center, Dallas, TX, United States, 4Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States

 
A substantial literature indicates distinct yet integrated anatomy and function along the longitudinal hippocampus axis. Some diseases also selectively affect anterior-posterior hippocampus regions. A number of rodent studies report cholinergic selectivity along the longitudinal (ventral-dorsal) axis of the hippocampus. Arterial spin labeling studies were performed to explore possible anterior-posterior differences in human hippocampus perfusion response to cholinergic challenge with the reversible cholinesterase inhibitor physostigmine. In agreement with the hypothesis suggested by the animal literature, a trend of larger rCBF response to physostigmine challenge in anterior hippocampus than in the rest of hippocampus was observed.

 
2905.   39 Subcortical Versus Cortical Effects of Anesthesia on Blood Oxygenation: in vivo Evidence from UHF MRI
Luisa Ciobanu1, Lynn Uhrig2, Boucif Djemai1, Denis Le Bihan1, and Béchir Jarraya2,3
1Neurospin, CEA, Gif sur Yvette, France, 2Equipe Avenir INSERM Bettencourt Schueller, Neurospin, CEA, Gif sur Yvette, France, 3Unité de Neurochirurgie Fonctionnelle, Henri-Mondor Hospital, Créteil, France

 
The non-invasive, in vivo monitoring of the effects of anesthetic agents on brain blood oxygenation remains highly challenging. Even when the systemic hemodynamics is kept stable, anesthetic agents can locally affect the cerebral hemodynamics and metabolism. Taking advantage of the increase in T2* contrast provided by UHF MRI (17.2 T) we study the effects of different anesthetic agents (isoflurane, propofol, midazolam, sevoflurane, ketamine and medetomidine) on the blood oxygenation in subcortical and cortical regions in a rat animal model.

 
2906.   40 in-vivo 19F Imaging of Sevoflurane in the Human Brain at Clinical-Relevant Concentrations
Maolin Qiu1, Ramachandran Ramani2, and Robert Todd Constable3
1Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States, 2Anesthesiology, Yale University School of Medicine, New Haven, CT, United States, 3Diagnostic Radiology, Yale University, New Haven, CT, United States

 
Direct Fluorine-19 imaging of anesthesia induced by Sevoflurane will provide important information about the pharmacokinetics of inhalational agents. Together with the pharmacology studies it may provide the whole picture of the neuronal mechanisms of general anesthesia. The extremely low cortical concentrations at clinically-relevant levels make in-vivo 19F imaging of cortical distributions in humans very challenging. With the aid of recent advances in imaging, we have successfully demonstrated in-vivo detecting regional Sevoflurane with a 1H/19F dual-tuned CP head coil during anesthesia at 0.5MAC. Our results not only support the observations from previous animal studies, but have provided new insight into the drug delivery of this agent.

 
2907.   41 Reliablity of MRSI Brain Temperature Mapping at 1.5T and 3T -permission withheld
Michael J. Thrippleton1, Jehill Parikh1, Bridget Harris2, Scott I. Semple3, Peter J. Andrews2, Joanna M. Wardlaw1, and Ian Marshall1
1Brain Research Imaging Centre, University of Edinburgh, Edinburgh, Lothian, United Kingdom, 2Department of Anaesthesia, Critical Care and Pain Management, University of Edinburgh, Edinburgh, Lothian, United Kingdom, 3Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, Lothian, United Kingdom

 
MRSI brain temperature mapping at 3T confers a small advantage compared with 1.5T with regard to precision. The largest source of variation arises between voxels.

 
2908.   42 MR Microscopy of Diseased Human Skin Using Phased-Array of Microcoils at 9.4 T: First Results -permission withheld
Katharina Göbel1, Oliver G. Gruschke2, Jochen Leupold1, Johannes S. Kern3, Cristina Has3, Jan G. Korvink2,4, Leena Bruckner-Tudermann3,4, Jürgen Hennig1, Dominik von Elverfeldt1, and Nicoleta Baxan1,5
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Lab. of Simulation, University of Freiburg - IMTEK, Freiburg, Germany, 3Dept. of Dermatology, University Medical Center Freiburg, Freiburg, Germany, 4Freiburg Institute for Advanced Studies, University of Freiburg, Freiburg, Germany, 5Bruker BioSpin MRI GmbH, Ettlingen, Germany

 
MRI of the skin as non invasive alternative to histopathology is challenging as dedicated approaches are required to overcome low sensitivity and contrast of standard MR investigations applied at microscale. The geometry of the skin with layers of large lateral dimensions and micrometre thickness demands high resolution over an enhanced FOV. Here, a home made MR detector arranged in a phased array geometry has been developed to surmount these challenges. Based on findings about coil performance and feasibility of high resolution imaging on healthy human skin, we present first results of diseased skin (Acne inversa) with direct comparison to histopathological sampling.

 
2909.   43 MR Imaging of Peripheral Nerves with Short and Ultrashort Echo Pulse Sequences
Graeme M. Bydder1, Richard M. Znamirowski2, Michael Carl3, and Nikolaus M. Szeverenyi2
1Radiology, University of California San Diego, San Diego, CA, United States, 2Radiology, University of California, San Diego, San Diego, CA, United States,3GE Healthcare, San Diego, CA, United States

 
In this study we describe imaging of peripheral nerves in tissue samples, intact cadavers and human subjects using short and ultrashort echo time (TE) pulse sequences. The emphasis was on detection of short T2 components within nerves. This is of particular interest in peripheral nerves because there is significant ordered collagen in all three layers of peripheral nerves and this tissue tends to have a short T2.

 
2910.   44 Cine 2D Phase-Contrast MRI Free of Blood Flow Artifacts to Study Cervical Cerebrospinal Fluid Flow.
Malek I. Makki1, Cyrile Cappel2, Bader Chaarani2, Catherine Gondry-Jouet3, and Olivier Baledent2
1MRI Research, University Children Hospital, Zurich, Switzerland, 2BioFlowImage, University Hospital Picardie Jules Verne, Amiens, France, 3Radiology, University Hospital Picardie Jules Verne, Amiens, France

 
The major source of errors affecting the assessment of cerebro-spinal fluid (CSF) dynamic with 2D cine phase-contrast MRI (cine-PC) in the aqueduct of Sylvius and the subarachnoid space are artifacts from blood leakage and inappropriate velocity encoding value. These make it difficult for an early and accurate diagnosis of impaired CSF flow and bias the quantification of velocity and volume leading to poor predictive outcome of surgical intervention. This investigation aims to develop a new 2D cine-PC sequence to assess CSF flow free of such artifacts and sensitive to slow CSF flow.

 
2911.   45 Effect of APOE4 on Partial Volume-Corrected Diffusion Anisotropy in Patients with AD and MCI®double prime
Kyung Mi Lee1, Min-Ji Kim2, Chang Woo Ryu2, Ji Seon Park1, Hak Young Rhee3, Eui Jong Kim1, and Geon-Ho Jahng2
1Radiology, Kyung Hee University Hospital, Kyung Hee University, Seoul, Seoul, Korea, 2Radiology, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Seoul, Korea, 3Neurology, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Seoul, Korea

 
To prospectively evaluate whether Apolipoprotein E4 (APOE4) carriers were altered in brain diffusion anisotropy compared with noncarriers in Alzheimer disease (AD), mild cognitive impairment (MCI) and cognitively normal (CN) subjects, 25 AD, 25 MCI, and 25 CN subjects were scanned DTI data. Furthermore, we applied a partial volume correction (PVC) method to minimize contributions of cerebrospinal fluid on FA and trace maps. We concluded that regional microstructural changes of brain in APOE4 carriers of AD and MCI subjects were found and application of the PVC should be helpful for accurate evaluation of microstructural changes in cognitive decline patients.

 
2912.   46 Microstructural Differences in the Aging White Matter of APOE Allele lower case Greek epsilon4 Carriers: A Diffusional Kurtosis Imaging and Diffusion Tensor Imaging Study
Jean-Philippe Coutu1,2, H. Diana Rosas1,3, and David H. Salat1,4
1MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States, 2Health Sciences and Technology, MIT/Harvard, Cambridge, Massachusetts, United States, 3Neurology, MGH, Harvard Medical School, Boston, Massachusetts, United States, 4Radiology, MGH, Harvard Medical School, Boston, Massachusetts, United States

 
Diffusion kurtosis imaging and diffusion tensor imaging have been used to investigate microstructural differences in the aging white matter of carriers of APOE allele lower case Greek epsilon4, a risk factor for sporadic Alzheimer's disease. Our study shows that carriers seem to have a greater cross-sectional increase in mean, axial and radial diffusivity and decrease in mean and radial diffusional kurtosis with increasing age, pointing to greater loss of diffusional heterogeneity. These findings could be observed as early as middle age, and might be related to the predisposition of carriers of APOE allele lower case Greek epsilon4 to sporadic Alzheimer’s disease.

 
2913.   47 Across-Session Reproducibility of DTI Derived Metrics Measured at 3T: PharmaCog Consortium
Jorge Jovicich1, Moira Marizzoni2, Roser Sala-Llonch3, Nuria Bargalló3, David Bartrés-Faz3, Jennifer Arnold4, Jens Benninghoff4, Jens Wiltfang4, Luca Roccatagliata5, Flavio Nobili5, Christian Zeeh6, Peter Schonknecht6, Giada Zoccatelli7, Franco Alessandrini7, Alberto Beltramello7, Hélène Gros-Dagnac8, Pierre Payoux8, Valérie Chanoine9, Jean-Philippe Ranjeva9, Mira Didic9, Melanie Leroy10, Regis Bordet10, and Giovanni Frisoni2
1University of Trento, Center for Mind/Brain Sciences, Mattarello, Trento, Italy, 2IRCCS San Giovanni di Dio Fatebenefratelli, LENITEM Lab of Epidem., Neuroim. & Telem, Brescia, Lombardia, Italy, 3Dept. Psychiatry and Clinical Psychobiology, Faculty of Medicine University of Barcelona, Barcelona, Barcelona, Spain, 4Department of Psychiatry and nuclear medicine, Universitaet Duisburg-Essen, Essen, Essen, Germany, 5Dept of Neuroscience, Ophthalmology and Genetics, University of Genoa, Genoa, Lombardia, Italy, 6Dept of Psychiatry and Dept of Neuroradiology, University of Leipzig, Leipzig, Leipzig, Germany, 7Dept of Neuroradiology, Verona General Hospital, Verona, Verona, Italy, 8U825 - Plateau Technique IRM, INSERM / Université Paul Sabatier, Toulouse, Toulouse, France, 9Hôpital La Timone CIC – UPCET, Marseille, Marseille, France, 10Universitè Lille UL2, Lille, Lille, France

 
Multi-site longitudinal diffusion MRI studies are of interest in the search for biomarkers that can reliably predict disease progression and/or therapeutic treatment effects. Previous multi-site 3T MRI studies evaluating across-session reproducibility are limited to few sites or to long dedicated acquisitions with multiple DTI averages. In this study we evaluate and compare across-session test-retest reproducibility of fractional anisotropy, mean, axial and radial diffusivities across eight different 3T MRI sites (Siemens, Philips, GE), on a group of healthy elderly subjects, using a single DTI acquisition that is part of a protocol aimed at studying other anatomical and functional parameters.

 
2914.   48 Investigation of the Precision of a Commercial Brain Volume Quantification Software
Yong Zhou1
1Radiology Services, Spectrum Health, Grand Rapids, MI, United States

 
In this investigation we have evaluated the precision of the volumetric measurement attainable by some recently available FDA approved commercial software. The results have shown significant variation that would need to be taken into account if this methodology is widely used in clinical diagnosis and longer monitoring of patients with dementia, such as Alzheimer’s disease.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (11:45-12:45) Exhibition Hall
Animal Models & Clinical Studies of Stroke

  Computer #  
2915.   25 High-Intensity Focused Ultrasound (HIFU) for Dissolution of Clots in a Rabbit Model of Embolic Stroke
Alison Burgess1, Yuexi Huang1, David Goertz1,2, and Kullervo Hynynen1,2
1Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada, 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada

 
In this study, we examine if stand-alone, high-intensity focused ultrasound (HIFU), can induce clot dissolution in a rabbit model of acute ischemic stroke. Emboli were delivered through the internal carotid artery and angiography was used to confirm blockage of the proximal middle cerebral artery. MRI was used to further characterize and target the clot for HIFU. At the highest power tested, HIFU restored flow in 5 of 7 (~71%) of blocked vessels. Histology was used to show that the targeted vessels remained intact following sonication. These results suggest that HIFU warrants further investigation as a thrombolytic therapy for ischemic stroke.

 
2916.   26 Investigation of the Cytoarchitectural Changes in Ischemic Infarction Using Cerebral Microenviroment Modeling (CMM)
Edward S. Hui1,2, Jens H. Jensen1,2, Xingju Nie1,2, Ali Tabesh1,2, Maria F. Falangola1,2, Joseph A. Helpern1,2, and DeAnna L. Adkins3
1Center for Biomedical Imaging, Medical University of South Carolina, Charleston, South Carolina, United States, 2Dept of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, United States, 3Dept of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, United States

 
Diffusional kurtosis imaging (DKI) has been demonstrated to be a promising tool for ischemic stroke assessment. Diffusional kurtosis of ischemic tissue has been shown in prior studies to remain elevated during subacute ischemia, amid pseudonormalization of diffusivity. However, these bulk diffusion metrics lack information on specific microstructural properties such as the sizes, orientations, volume fractions, and diffusivities of prescribed cellular compartments. In this work, we employ a new tissue model, termed cerebral microenvironment modeling (CMM), which generalizes a previously proposed method so that specific microstructural properties of cortical infarction may be obtained with DKI.

 
2917.   27 Pulsed Arterial Spin Labeling for CBF MRI in Non-Human Primate Model of Stroke
Kai-Hsiang Chuang1, Elaine Manigbas2, Douglas Collins2, Flordeliza de Villa2, Rosario Perez2, and Lynn Collura2
1Magnetic Resonance Imaging Group, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore, Singapore, 2Maccine Pte Ltd, Singapore, Singapore, Singapore

 
We assessed using pulsed ASL for CBF measure in a middle cerebral artery occlusion (MCAO) model in the cynomolgus macaque. PICORE ASL was applied before and 24 hours after 3-hour transient MCAO. Good perfusion signal was obtained in all animals and showed extensive reduction of CBF comparable to ADC. However the large variation and very long transit time leaded to hyperintensity in artery and underestimation of CBF. Very long inversion time would be needed to quantify the CBF in this model.

 
2918.   28 Imaging of Tissue pH Response to Oxygen Therapy in a Rodent Model of Acute Stroke -permission withheld
Phillip Zhe Sun1, Yu Wang1, Jie Lu2, Xunming Ji2, and Eng H. Lo3
1Radiology, Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Radiology, Xuanwu Hospital, Beijing, Beijing, China, 3Radiology and Neurology, Martinos Center for Biomedical Imaging, Charlestown, MA, United States

 
Normobaric oxygen (NBO) treatment is a promising treatment strategy that may mitigate ischemic tissue damage. However, the mechanisms of NBO therapy are poorly understood, elucidation of which may assist development of more effective combinational treatment. Given that pH is a surrogate tissue metabolic marker, our study applied pH imaging to evaluate the emerging NBO treatment. Our pilot study found that whereas penumbral tissue showed pH recovery upon initiation of NBO therapy, its pH degraded significantly after the termination of NBO. Our pilot data suggest that NBO may transiently relieve ischemic tissue injury, and reperfusion is needed for long-term outcome improvement.

 
2919.   29 Assessment of Pharmacologically Induced Hypothermia Treatment in a Rodent Model of Focal Cerebral Ischemia by Using Diffusion Tensor Imaging
Silun Wang1, Xiaohuan Gu2, Ko-Eun Choi2, Yumei Yan1, Ling Wei2, Shan-Ping Yu2, and Xiaodong Zhang1
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Department of Anesthesiology and Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States

 
We evaluated the pharmacologically induced hypothermia treatment response in focal cerebral ischemia induced white matter injury in a mice model using DTI. Results indicated that significantly reduced infraction volume in the treatment group compared to control group. Significantly decreased FA and λ// were only found in the ipsilateral external capsule and fornix than contralateral sides in control group. Less reduction of FA and λ// were found in the hypothermia treated group. Our results support the use of DTI as a biomarker to non-invasively monitor the hypothermia treatment response in ischemia induced stroke injury.

 
2920.   30 Diffusion Tensor Imaging of Acute Axonal Degeneration Following Neonatal Cerebral Hypoxia-Ischemia in Rats
Ursula I. Tuor1,2, Melissa Morgunov1, Manasi Sule1, Min Qiao1, Tadeusz Foniok2, and Adam Kirton3
1Physiology and Pharmacology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada, 2Experimental Imaging Centre, University of Calgary, Calgary, Alberta, Canada, 3Pediatrics and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada

 
Cerebral hypoxia-ischemia (HI) in neonates causes perinatal brain damage and subsequent injury in descending tracts (e.g. cerebral peduncle). Diffusion tensor imaging (DTI) and histological changes were investigated at 2h,1d,2d and 7d post-HI in neonatal rats. In cerebral peduncle: ADC and eigenvalues were reduced acutely normalizing/increasing by 7d; FA ratios, fiber tracts and neurofilament staining were reduced ipsilaterally at all times; staining for myelin, microglia/macrophages or reactive astrocytes was unchanged acutely. Axonal changes in cerebral peduncle are detected within hours following hypoxia+unilateral ischemia using standard imaging and DTI. FA detects well axonal degenerative changes at acute and subacute time points.

 
2921.   31 Incorporating ADC Temporal Profiles to Predict Ischemic Tissue Fate in Acute Stroke
Qiang Shen1, Virendra Desai1, and Timothy O. Duong2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, Texas, United States

 
Acute diffusion data has been used to predict ischemic tissues fate on a pixel-by-pixel basis. Predictions however were made based on acute MRI data from a single time point. This study proposes a novel approach to incorporate the temporal characteristics of acute ADC (apparent diffusion coefficient) changes to characterize tissue fate based on a pixel by pixel basis. This approach was tested on rat stroke models subjected to permanent, 60-min and 30-min middle cerebral artery occlusion (MCAO). We concluded that there were distinct temporal patterns that determined tissue salvageability and incorporating temporal information can improve prediction accuracy.

 
2922.   32 Effects of Occlusion Duration on Infarct Volume and Tissue Fate in Ischemic Stroke
Qiang Shen1, Fang Du1, Shiliang Huang1, Yash Vardhan Tiwari1, and Timothy O. Duong2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, Texas, United States

 
We evaluated the initial lesion volume 30 mins after stroke and infarct volume at day 2 for multiple middle cerebral arterial occlusion (MCAO) durations in rats. Our results showed that the infarct volumes at day 2 were smaller than the initial lesion volumes at 30 mins after MCAO in 30- and 45-min MCAO groups but larger in 60- and 90-min groups. In the 30-min MCAO group, half the initial ADC lesion was reversed, whereas in the 60- and 90-min MCAO groups, only about 10% of the initial ADC lesion was reversed, and there was a weak dependence on duration.

 
2923.   33 Preclinical Study of Stroke Using T2relaxometry and Diffusion Weighted Imaging
Dushyant Kumar1,2, Peter Ludewig3, Ashish Raj4, Tim Magnus3, Jens Fiehler1, Christoph Heesen5, Susanne Siemonsen1,2, and Jan Sedlacik1
1Neuroradiology, University Medical Center, Hamburg, Hamburg, Germany, 2Multiple Sclerosis Imaging Center, University Medical Center, Hamburg, Hamburg, Germany, 3Neurology, University Medical Center, Hamburg, Hamburg, Germany, 4Radiology, Weill Cornell Medical College, Newyork, New York, United States,5Institute for Neuroimmunology and Clinical MS Research, University Medical Center, Hamburg, Hamburg, Germany

 
Problem: White matter (WM) lesions are shown to have prognostic values in predicting stroke occurrence and recurrence in patients. Though T2-weighted images can be used to detect the WM lesion and stroke core, it lacks in specificity. Methods: To gain better understanding of stroke lesion progression, we applied quantitative T2-relaxometry (QT2R) and diffusion weighted imaging in a mouse stroke model. Results & Conclusions: We demonstrate the feasibility of QT2R at moderate SNR and high resolution. We also demonstrate that by combining ADC data to QT2R analysis, it may be possible to gain better understanding of the progression of stroke lesions.

 
2924.   34 Evolution of Diffusion Tensor Parameters of Ischemic Penumbra and Infarct Core in a Rat MCA Occlusion Model
Duen-Pang Kuo1,2, Hsiao-Wen Chung3, Chen Chang4, Huan-Chu Lo2, and Cheng-Yu Chen5
1Electrical Engineering, National Taiwan University, Taipei, Taiwan, 2Department of Radiology, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan,3National Taiwan University, Taipei, Taiwan, 4Academia Sinica, Taipei, Taiwan, 5Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan

 
The aim of this research is to measure the FA in IP and IC regions respectively, as well as longitudinal observation of the FA in those regions.

 
2925.   35 Combination of SWI, DWI and 3D Capital Greek DeltaR2-Based Micro-MRA for Predicting Stroke Evolution in Rat with Middle Cerebral Artery Occlusion
Ping-Huei Tsai1,2, Yi-Hua Hsu3, Yu-Yin Tung3, Chien-Hsiang Huang3, Chiao-Chi Chen3, Wing P. Chan2, and Fong Y. Tsai1
1Imaging Research Center, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan,3Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan

 
The purpose of this study is using SWI, DWI and 3D £GR2-based micro-MRA to assess the relationship between them and stroke evolution in rats with middle cerebral artery occlusion (MCAO) during progression of stroke. Our preliminary finding demonstrates that the combination of SWI, DWI and 3D £GR2-based micro-MRA provides additional information for evaluation of rat brain with acute ischemic stroke, and may have a potential to contribute to determining the penumbra and predicting of the stroke prognosis, as well as further quantitative measurements.

 
2926.   36 Blood Volume in Response to Hypercapnia: MRI Study Using Spontaneously Breathing Mice
Ji-Yeon Suh1, Woo Hyun Shim1, Christian Thomas Farrar1, Jeong Kon Kim2, and Young Ro Kim1
1Athinoula A, Martinos Center for Biomedical Imaging, Massachusettes General Hospital, Charlestown, MA, United States, 2Department of medical imaging, Asan Medical Center, University of Ulsan, Seoul, Korea, Democratic People's Republic of

 
Cerebral vasoreactivity to hypercapnic stimulation has been used for assessing the cerebrovascular function altered by various pathophysiological states. In this study, in order to characterize hemodynamic changes during the inhalation of different CO2 gas concentration, multiple MRI-derived hemodynamic parameters were measured using an alternating GE/SE EPI and an intravascular contrast agent in the spontaneously breathing mice. Significant vasodilation was observed, in which the dynamic features of response curve and response magnitude were CO2 dose-dependent. Our results demonstrated the experimental setting that produces consistent vasoreactive responses in mice, thus validating the hypercapnic method that can be used to evaluate the altered hemodynamic function in various cerebrovascular disease models.

 
2927.   37 Differences in Iron Particle Enhanced MRI of Brain and Spinal Cord Lesions in MOG-Induced Eae Mice
Xiaowei Zhang1, Bill Siders2, Xiaoyou Ying2, and Russell E. Jacobs1
1Biological Imaging Center, California Institute of Technology, Pasadena, CA, United States, 2R&D Hub, Sanofi Boston, Boston, MA, United States

 
Brain and spinal cord EAE (experimental allergic encephalomyelitis) lesions in MOG35-55 induced EAE mice were imaged using a T2* weighted FLASH protocol at pre and post iron injection throughout the time course EAE acquisition. EAE lesions in the brain and spinal cord could be readily identified prior to iron injection. Comparison between the pre and post iron images revealed that administration of Feraheme had limited ability to improve MRI lesion detection.

 
2928.   38 A Digital White Matter Atlas of the Rhesus Macaque Brain
Elizabeth Zakszewski1, Nagesh Adluru1, Ned Kalin1, and Andrew L. Alexander1
1University of Wisconsin-Madison, Madison, WI, United States

 
Since ROI-based analysis of WM pathways in the rhesus macaque is useful in studies using diffusion tensor imaging (DTI) data, we have here created an atlas based on a publicly available DTI-based template of young rhesus macaques. The atlas was constructed to mimic the structure of an existing human atlas that is widely used, making results translatable between species. Parcellations were carefully hand-drawn on a principle-direction color coded fractional anisotropy image of the population template. The resulting atlas can be used as reference to which to register individual rhesus data for the purpose of white-matter parcellation, or individual regions from the atlas may be warped into individual space to be used in ROI-based analyses.

 
2929.   39 In Ovo MRI and MRS of the Turkey Embryo
Jürgen Baudewig1, Kristin Kötz1, Denis Schewe2, and Susann Boretius1
1Klinik für Diagnostische Radiologie, Sektion Biomedzinische Bildgebung, Christian-Albrechts-Universität, Kiel, Germany, 2Klinik für Allgemeine Pädiatrie, Christian-Albrechts-Universität, Kiel, Germany

 
Increasing awareness in animal protection creates a significant demand for alternatives to conventional animal experiments. Here, we wanted to evaluate the potential of MRI and MRS methods to study anatomical and metabolic changes of living turkey embryos in ovo. Immobilizations by cooling and by isoflurane anesthesia were compared concerning effects on motion artifacts and on brain metabolites. 10 min of ice-cooling allowed for almost motion-artifact-free MRI and MRS without any detectable impairment of viability. Moreover, as shown on the example of ethanol, localized proton magnetic resonance spectroscopy may be used in this model to obtain neurochemical profiles.

 
2930.   40 Characterization of a Novel MRI-Detectable Nanoantioxidant
Taeko Inoue1, Tabassum Majid2, Daniela Marcano3, Errol L. Samuel3, Helen Zheng3, James Tour3, and Robia G. Pautler2,4
1Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, United States, 2Interdepartmental Program for Translational Biology & Molecular Medicine, Baylor College of Medicine, Houston, TX, United States, 3Department of Chemistry, Rice University, Houston, TX, United States,4Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, United States

 
Oxidative stress is the imbalance of pro-oxidant and antioxidant molecules in favor of pro-oxidants. This imbalance leads to damage of DNA, proteins, lipids, interference of key signaling pathways and has been well documented to play a key role in pathogenesis of many neurodegenerative diseases such as Alzheimer’s disease. As a result, there have been many antioxidant-based therapies throughout the years targeted at fighting oxidative stress. They have, however, been largely ineffective due to low radical scavenging efficacy, as well as, poor localization in needed areas. As a result, we have developed a nanoantioxidant that can potentially meet several of the currently unmet needs.

 
2931.   41 Histological Correlation with Diffusion MRI to Monitor Transient and Permanent Cell Permeabilization in the Brain
Faisal Mahmood1, Rasmus H. Hansen2, Birgit Agerholm-Larsen3, Hanne Gissel4, Per Ibsen5, and Julie Gehl1
1Department of Oncology, Copenhagen University Hospital, Herlev, Denmark, 2Herlev Hospital, Herlev, Denmark, 3Glostrup Hospital, Glostrup, Denmark,4Aarhus University, Aarhus, Denmark, 5Hvidovre Hospital, Hvidovre, Denmark

 
Purpose: To evaluate diffusion weighted MRI (DW-MRI) as a non-invasive technique to monitor permeabilized zones in the brain. Methods: Using an in vivo rat brain model, electroporation was applied for inducing transient and permanent cell permeabilization in predefined zones. DW-MRI was acquired up till 48 hr after electroporation. Results: Significant changes in ADC and kurtosis were observed in the permeabilized zones, showing temporal differences between transiently and permanently permeabilized zones. These findings were correlated with histology. Conclusions: DW-MRI may potentially be used for response evaluation of membrane permeabilizing treatments, such as radiation therapy of cancer.

 
2932.   42 Neurotoxicity Biomarker Development Using T2 Mapping in Kainic Acid Excitotoxicity Rat Model
Serguei Liachenko1, Jaivijay Ramu1, Merle G. Paule1, Larry Schmued1, and Joseph Hanig2
1Division of Neurotoxicology, NCTR / FDA, Jefferson, AR, United States, 2CDER/FDA, White Oak, MD, United States

 
Assessing neurotoxicity is a very important part of the evaluation of new drug safety and is usually assessed using conventional histology and biochemistry. The current study utilizes non-invasive MRI techniques involving T2 mapping approach to enable the development of the sensitive early biomarkers of neurotoxicity. Acute changes in T2 values consistent with the neurotoxic mechanism of action of prototypic compounds were detected as early as 2 hours after injection of kainic acid. Such methodology has the potential to improve our understanding of brain toxicity and provide promising tools for the development and qualification of new biomarkers of neurotoxicity.

 
2933.   43 Behavior of the Statistical Distribution and Diffusion Kurtosis Models in Human Ischemic Stroke
Chu-Yu Lee1,2, Kevin M. Bennett3, and Josef P. Debbins1,2
1Neuroimaging Research, Barrow Neurological Institute, Phoenix, Arizona, United States, 2Electrical Engineering, Arizona State University, Tempe, Arizona, United States, 3School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona, United States

 
The apparent diffusion coefficient (ADC) of the monoexponential model has been shown to decrease following ischemic stroke. The underlying mechanisms of the reduction in the ADC remain unclear. The increased cell volume fraction is suggested to be one mechanism that results in more hindered extracellular diffusion. However, the intracellular diffusion was found to decrease or increase by separate studies. Another factor of reduced membrane permeability was shown to have a minor impact on the reduced ADC. Recently, with a b-value up to 2500 s/mm2, the statistical distribution model and diffusion kurtosis model (DKI) have been used to study biophysical and pathological changes, potentially exhibiting higher sensitivity compared to the ADC. The aim of this study was to investigate the relationship between the non-monoexponential models and microstructural changes in ischemic stroke. For this purpose, we studied the fitted parameters: σstat of the statistical distribution model (width of the distribution of diffusion rates) and Kapp of the DKI model (measure of non-Gaussian diffusion) in response to the simulated microstructural changes. We compared our simulation results to the in vivo measurements of human ischemic stroke (n = 6). The results suggest that the non-monoexponential models may be useful in identifying the biophysical mechanisms in ischemic stroke.

 
2934.   44 Myelin Plasticity Does Not Significantly Influence Diffusion Remodelling of the Uninjured Motor Network After Stroke
Ying-Chia Lin1, Alessandro Daducci2, Djalel Eddine Meskaldji2, Gloria Menegaz1, Jean-Philippe Thiran2,3, Reto Meuli3, Gunnar Krueger4,5, and Cristina Granziera5,6
1Computer Science, University of Verona, Verona, Italy, 2Signal Processing Lab 5 (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3Radiology, CHUV, Lausanne, Switzerland, 4Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, 5CIBM-AIT, Ecole Polytechnique Federal de Lausanne (EPFL), Lausanne, Switzerland, 6Neurology, CHUV, Lausanne, Switzerland

 
Connectivity plasticity in the uninjured hemisphere after stroke has been reported in a number of experimental and human studies with diffusion MRI. Whether the observed changes in diffusion properties (es. FA) are due to axonal remodeling or myelin plasticity remains however an open issue. In this context, we wanted to study the behaviour of the Magnetisation Transfer Ratio in the contra-lateral motor network and to correlate it to the longitudinal changes in diffusion anisotropy.

 
2935.   45 Diffusion Kurtosis Image of the Cerebral Infarction: Time Course of the Axial and Radial Kurtosis
Toshiaki Taoka1, Masayuki Fujioka2, Masahiko Sakamoto1, Toshiaki Akashi1, Toshiteru Miyasaka1, Tomoko Ochi1, Saeka Hori1, Takeshi Wada1, Masato Uchikoshi3, and Kimihiko Kichikawa1
1Radiology, Nara Medical University, Kashihara, Nara, Japan, 2Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan,3Siemens Japan KK, Shinagawa, Tokyo, Japan

 
Diffusion kurtosis reported to be increase in the lesions of acute cerebral infarction. However, time course of the diffusion kurtosis of the cerebral infarction is not investigated enough. The purpose of the current study is to evaluate the changes in diffusion kurtosis in the cases with early cerebral infarction. Diffusion kurtosis value which is axial to the eigenvector showed increase in the lesions of the early infarction and showed earlier decrease compared to the diffusion weighted images. Additional information for the tissue with very early infarction will be provided by diffusion kurtosis imaging.

 
2936.   46 Perfusion and Structural Characteristics in the Grey & White Matter of Young and Elderly Adults with White Matter Disease: A Pseudo-Continuous ASL and VBM Study
David E. Crane1, Sandra E. Black1,2, Anoop Ganda1, Deanna S. Reynolds3, and Bradley J. MacIntosh1,4
1Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Research Institute, Toronto, ON, Canada, 2Department of Medicine, Division of Neurology, University of Toronto, Toronto, ON, Canada, 3Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 4Medical Biophysics, University of Toronto, Toronto, ON, Canada

 
Unlike contrast-enhanced perfusion-weighted imaging techniques like Dynamic Susceptibility Contrast MRI or Single Photon Emission Computed Tomography, Arterial Spin Labeling (ASL) relies on tracer kinetics from magnetically labeled blood water to estimate perfusion. Two disadvantages of the ASL technique are 1) the low signal-to-noise ratio and 2) the relatively short half-life. In this aging study (total N=35 elderly, 16 young) we characterize perfusion signals in grey, white and white matter diseased tissues types. A voxel-based morphometry (VBM) analysis was performed to reveal hippocampal grey matter is negatively correlated with extent of white matter disease.

 
2937.   47 Intracellular Contributions to MR Diffusion Contrast in Stroke: Intraneuronal Viscosity and Neurite Beading
William M. Spees1,2, Dmitriy A. Yablonskiy1,3, G. Larry Bretthorst1, Alexander L. Sukstankii1, Jeffrey J. Neil1,4, and Joseph J.H. Ackerman1,5
1Department of Radiology, Washington University, St. Louis, MO, United States, 2Hope Center for Neurological Disorders, Washington University, St. Louis, MO, United States, 3Department of Physics, Washington University, St. Louis, MO, United States, 4Department of Pediatric Neurology, Washington University, St. Louis, MO, United States, 5Department of Chemistry, Washington University in St. Louis, St. Louis, MO, United States

 
The source of the post-ischemic drop in the apparent diffusion coefficient of water in brain remains in question. In the current work, the diffusion properties of the intraneuronal metabolite N-acetylaspartate are characterized according to a biophysical model in rat brain pre- and post-ischemia at 37 °C. Based on the model, which accounts for local, microscopic diffusion anisotropy and diffusion kurtosis, a ~19% increase in intraneuronal cytoplasmic viscosity post-ischemia and evidence (via the increase in the kurtosis term) for beading of neurites are observed. Neither occurrence appears of sufficient magnitude to account principally for the decrease in water diffusion with stroke.

 
2938.   48 Automatic Segmentation of Diffusion MRI from the Genes Associated with Stroke Risk and Outcomes Study
Steven Mocking1, Natalia S. Rost2, Kaitlin M. Fitzpatrick2, Allison Kanakis2, Lisa Cloonan2, Jonathan Rosand2, Karen L. Furie3, and Ona Wu1
1Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Department of Neurology, Massachusetts General Hospital, Boston, MA, United States, 3Department of Neurology, Brown University, Providence, RI, United States

 
Automated Algorithms for segmenting ischemic stroke lesions in diffusion MRI based on ADC thresholding and Naive Bayes classification are evaluated against manual outlines in independent data from stroke patients seen with 48 h of admission. Manual outlines took approximately 5-30 minutes/subject. Naive Bayes significantly outperformed ADC thresholding in terms of voxel-wise sensitivity and Dice similarity metric. Both automated algorithms took 20-40s/subject.Genome wide association studies seeking to link genetic variants with imaging phenotypes that require thousands of subjects would benefit from automated lesion segmentation techniques.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (10:45-11:45) Exhibition Hall
Normal Developing Brain

  Computer #  
2939.   49 A Quantitative Diffusion Tensor Magnetic Resonance Histology Atlas of Rat Brain Development
Evan Calabrese1, Alexandra Badea2, and G. Allan Johnson1,2
1Biomedical Engineering, Duke University, Durham, NC, United States, 2Radiology, Duke University, Durham, NC, United States

 
The rat is a powerful model system for studying neurodevelopment and neurotoxicology. However, the complex spatiotemporal changes that occur during rat neurodevelopment remain to be elucidated. This work establishes the first diffusion tensor magnetic resonance histology (DT-MRH) atlas of the developing rat brain. The atlas establishes a timeline of normal morphometric and diffusion tensor changes throughout neurodevelopment and represents a quantitative database of rat neurodevelopment for characterizing rat models of human neurologic disease. We demonstrate the use of the atlas as a database for quantitative morphometry and DTI tissue microstructural metrics throughout normal postnatal neurodevelopment.

 
2940.   50 in vivo Diffusion Tensor Imaging of the Neonatal Rat Brain Development -permission withheld
Markus Breu1,2, Dominik Maria Reisinger1,2, Dan Wu3, Yajing Zhang3, Ali Fatemi1,2, and Jiangyang Zhang4
1Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, United States, 2Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States

 
To investigate the relationships between diffusion tensor imaging (DTI) based markers and micro-structural changes in the developing brain, in vivo high resolution DTI was used to characterize neonatal rat brain development from postnatal day 2 (P2) to P10. The DTI contrasts allowed delineation and tracking of major structures in the neonatal rat brain. The results showed modest increases in apparent diffusion coefficient (ADC) and small increases in fractional anisotropy (FA) in major white matter structures at P2-P10. During the same period, rapid decline in FA and complex changes in ADC were found in the neonatal cortex.

 
2941.   51 Development of Cerebellar Connectivity in Human Fetal Brains Revealed by High Angular Resolution Diffusion Tractography -permission withheld
Emi Takahashi1, Emiko Hayashi1, Rebecca D. Folkerth2, Jeremy D. Schmahmann3, and Patricia Ellen Grant4
1Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Brigham and Women's Hospital, Boston, MA, United States,3Massachusetts General Hospital, Boston, MA, United States, 4Boston Children's Hospital, Boston, MA, United States

 
Our objective in this study was to further apply HARDI tracography to the developing human cerebellum ranging from fetal to toddler stages, to outline in broad strokes the 3-dimensional development of white matter and local gray matter organization in the cerebellum. Our results show the usefulness of HARDI tractography to image developing cerebellar connectivity. We observed regression of radial organization in the cerebellar cortex and the emergence of regional specificity of cerebellar peduncles that were similar to our previous observations on the development of cerebral cortex. Our results demonstrated the potential for HARDI tractography to improve our understanding of neuronal circuitry and connectivity in both white and gray matter in the developing cerebellum.

 
2942.   52 Regression Into Early Adulthood: A Data-Driven Perspective of NIH Longitudinal Pediatric DTI Study -permission withheld
Yasheng Chen1, Hongtu Zhu2, Hongyu An2, Dinggang Shen2, and Weili Lin2
1University of North Carolina, Chapel Hill, NC, United States, 2UNC-CH, Chapel Hill, NC, United States

 
Most of the current brain developmental studies model growth trajectory with a global parametric model such as nonlinear polynomials. These approaches may neglect subtle local temporal features in the data and the physiological meanings of the derived high order nonlinear polynomial terms may be elusive. To overcome these limitations, we proposed a powerful approach to model brain growth for large-scale longitudinal datasets from NIH pediatric DTI brain developmental study. Through the combination of the greater flexibility of the free-knot B-spline fitting with quasi-least squares longitudinal analysis, we are able to delineate the complex process of brain growth from newborns to early adulthood into a series of linear spans so that growth velocity based physiological inference can be made.

 
2943.   53 Diffusion Changes in Early Brain Development Beyond Diffusion Tensor Imaging -permission withheld
Yasheng Chen1, Hongtu Zhu2, Hongyu An2, Dinggang Shen2, John Gilmore2, and Weili Lin2
1University of North Carolina, Chapel Hill, NC, United States, 2UNC-CH, Chapel Hill, NC, United States

 
DTI based early brain developmental study has limitations in quantifying complex white matter structures. In this study, we have performed a large scale longitudinal analysis on diffusion profiles obtained with multiple encoding directions (HARDI). In early brain development, we found significant temporal changes of multiple HARDI parameters including the absolute power, relative weight and geometrical shapes of diffusion profiles represented by high order spherical harmonics. To the best of our knowledge, our study is the first diffusion based early brain developmental study moving beyond the DTI regime.

 
2944.   54 DTI Correlates of Brain Network Topology in a Pediatric Population
Vincent J. Schmithorst1, Ashok Panigrahy1, and Jessica L. Wisnowski1
1Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States

 
We investigated the relation between global functional network topology, as measured by intrinsic-connectivity fMRI (ic-fMRI), and DTI parameters, which reflect regional differences in white matter microstructure, in preadolescent Brazilian children. Changes were predominantly located in a single crossing-fiber region in the right hemisphere involving the corona radiata, superior longitudinal fasciculus, and callosal fiber. FA was positively correlated with network integration and negatively with network segregation. FA increases were due to increased AD and decreased RD, indicating increased fiber organization in a white matter region connecting distal regions of the brain is associated with more efficient cognitive function.

 
2945.   55 Small-World Brain Networks in Resting State in Typically Developing Children and Adolescents
Minjie Wu1, Alexander Kmicikewycz1, Donatello Arienzo1, Lisa Lu1,2, Shaolin Yang1, and Mani Pavuluri1
1Psychiatry, University of Illinois at Chicago, Chicago, IL, United States, 2Psychology, Roosevelt University, Chicago, IL, United States

 
Combining rs-fcMRI and graph theory analyses, this study aims to quantitatively characterize the organizational change of functional brain networks in normal development during childhood and adolescence. No significant correlation was found between age and global network metrices (small-worldness or global efficiency). Significant age-related changes were found in local efficiency and degree at node level at right lingual gyrus, left medial orbitofrontal area, pericalcarine, anterior cingulate gyri. These age-related changes in node-level metrices but not global metrices may suggest topological fine tuning of resting state brain networks in children and adolescents.

 
2946.   56 Unilateral Hearing Loss in Children Affects Development of the Default Mode Network
Vincent J. Schmithorst1,2, Scott Holland2, and Elena Plante3
1Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, 2Radiology, Children's Hospital Medical Center, Cincinnati, OH, United States, 3Speech, Language, and Hearing Sciences, University of Arizona - Tucson, Tucson, AZ, United States

 
Little is currently known about how subtle sensory deficits may affect the development of higher-order cognitive processing. Children with unilateral hearing loss (UHL) exhibit deficits in sound localization, as the additional information from binaural input is unavailable. We investigated the neural correlates of audio-visual association in children with UHL as compared with normal-hearing controls. While minimal differences in activation patterns were seen, children with UHL displayed reduced deactivation in anterior and posterior default-mode network (DMN) regions. This neurobiological deficit, also seen in ADHD and math disability, may underlie the academic and behavioral deficits seen in children with UHL.

 
2947.   57 Altered Metabolism in the Developing Auditory Cortex of Chicks Exposed to Chronic High Decibel Noise: A Proton NMR-Based Metabonomic Study
Vivek Kumar1, Pawan Kumar2, Uma Sharma2, T C. Nag1, Naranamangalam R. Jagannathan2, and Shashi Wadhwa1
1Department of Anatomy, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
Proper functional development of the auditory cortex and its synaptic connections require balance between excitatory and inhibitory neurotransmission, which is affected by the acoustic stimulation. Our proton NMR data showed that chronic noise exposure significantly decreases GABA level and increases the glutamate level. This NMR based metabonomic study revealed that chronic exposure of high decibel sound (110dB) significantly alters this balance in the developing auditory cortex. Further, results indicated that the sound characteristic [patterned (music) and un-patterned (noise)] has a profound effect on this balance. High sound pressure level also significantly affects the energy metabolism of the developing auditory cortex.

 
2948.   58 A Quantitative Analysis of the Very Preterm Brain at 30 and 40 Weeks Gestational Age; Correlation of Multi-Component T2 Relaxation and Diffusion Tensor Anisotropy.
Andrew Melbourne1, Giles Kendall2, Alan Bainbridge3, Manuel Jorge Cardoso1, Nicola Robertson2, Neil Marlow2, and Sebastien Ourselin1
1Centre for Medical Image Computing, University College London, London, United Kingdom, 2Institute for Womens Health, University College London, London, United Kingdom, 3University College London Hospitals NHS Foundation Trust, London, United Kingdom

 
This work investigates correlations between multi-component T2 imaging and diffusion imaging in the neonatal brain at 30 and 40 weeks equivalent gestational age.

 
2949.   
59 Generating a Human Neonatal Brain Atlas for Superior Normalization Accuracy
Yajing Zhang1, Linda Chang2, Thomas Ernst2, Jon Skranes3, Steven Buchthal2, Daniel Alicata2, Heather Johansen2, Antonette Hernandez2, Robyn Yamakawa2, Lillian Fujimoto4, Michael Miller1, Susumu Mori5, and Kenichi Oishi5
1Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States, 2University of Hawaii at Manoa, Honolulu, Hawaii, United States, 3Department of Laboratory Medicine, Children's & Women's Health, Norwegian Univ. of Science and Technology, Trondheim, Norway,4Straub Mililani Clinic, Mililani, Hawaii, United States, 5Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States

 
MRI is a sensitive method for detecting subtle anatomical abnormalities in neonatal brains. The tissue composition of the neonatal brain is substantially different from that of the adult, and therefore, the use of a neonate-specific atlas might be more appropriate. To optimize the normalization, we introduce a method to create a Bayesian neonatal brain atlas to represent the studied population. Anatomical parcellation can be obtained automatically, avoiding the labor-intensive manual drawings of 3D ROIs. This tool is expected to be applicable for whole-brain detection of subtle developmental abnormalities, and for identifying MRI-based markers of neurological disorders in neonatal brain development.

 
2950.   60 Quantitative Correlations Between Gray Matter Volume and White Matter Tracts in Frontal and Occipital Regions in Preschool Children: Assessment Combined 3D T1WI and DTI
Xue Luo1,2, Jie Gao1, Xianjun Li1,2, Mingxi Wan3, and Jian Yang1,2
1Department of Radiology, The First Affiliated Hospital of Medical College, Xi¡¯an Jiaotong University, Xi'an, Shannxi, China, 2School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shannxi, China, 3School of Life Science and Technology, Xi'an, Shannxi, China

 
The aim of this study is to combine 3D T1WI and DTI to primarily investigate the correlations between the variations of GM and WM in frontal lobe and occipital lobe during preschool period. FreeSurfer and MedINRI were used to analyze 3D T1WI and DTI data separately. The results of correlation analysis showed there were strong positive correlations between GM volume of frontal cortex, occipital cortex and numbers of fibers through these two cortexes and age. The correlation coefficients related with frontal cortex were all larger than them related with occipital cortex. This is the first study that demonstrated the positive relationship between GM volume in frontal cortex and occipital cortex and number of WM fibers through corresponding cortex in preschool children.

 
2951.   61 Quantitative Assessments of Growth Trajectories of Cortical Thickness During the First 18 Mons of Life
Weili Lin1, Li Wang1, Gang Li1, Feng Shi1, Jingxin Nie1, and Dinggang Shen1
1Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States

 
Healthy pediatric subjects were recruited for a longitudinal study. Each subject was scanned every three mons starting from birth to 1 yr-old and again at 18mons old. A novel approach taking advantage information available from the longitudinal design was employed for CTH measures. The CTH of the temporal and frontal lobes outgrow the parietal and occipital lobes and reach ~ 4mm at 18mons. The primary language and auditory areas exhibit the largest CTH increase CTH < 6mons of life when compared to motor/sensory/visual cortices. Interestingly, the visual cortex exhibits a relatively stable CTH throughout the first 18mons of life.

 
2952.   62 Coordinated Anatomical Growth of Motor, Sensory, and Visual Networks in Early Infancy
Weili Lin1, Wei Gao1, Feng Shi1, Li Wang1, Gang Li1, Jingxin Nie1, Hongtu Zhu1, and Dinggang Shen1
1Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

 
It has been suggested that brain regions with similar functions may exhibit a similar growth trajectory, also known as coordinated brain growth. Using gray and white matter volume and cortical thickness growth trajectories during the first 18mons of life through a longitudinal imaging study of normal pediatric subjects, brain structural networks of motor, sensory and visual functions were discerned. Results are consistent with the known brain regions possessing these functions. The existence of coordinated brain anatomical growth in early infancy may offer an invaluable tool to explore maturation processes of higher order brain functional networks during early brain development.

 
2953.   63 Developmental Trajectories of Global OEF, CBF, CMRO2 Using Susceptibility-Based Oximetry, Phase Contrast MRI and ASL
Mayank A. Jog1, Emily Kilroy2, Varsha Jain3, Felix Wehrli3, and Danny J.J. Wang2
1Biomedical Engineering, University of California Los Angeles, Los Angeles, California, United States, 2Neurology, University of California Los Angeles, Los Angeles, California, United States, 3Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, United States

 
This study explored the developmental trajectories of global oxygen extraction fraction (OEF), cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in 47 children aged 7 to 17. A novel non-invasive MRI method was utilized including susceptometry to quantify OEF, phase-contrast (PC) MRI to quantify CBF and Fick’s principle for CMRO2. CBF and CMRO2 were found to decrease with age while OEF did not vary with age. PC measurements of global CBF were positively correlated with pseudo-continuous ASL measurements, lending support to the validity of this method.

 
2954.   64 Using MRI to Quantify Forebrain Development of a Common Neurobehavioral Animal Model, the Zebrafish (Danio Rerio), Reared in Different Conditions
Thomas Neuberger1,2, Cairsty Grassie3, and Victoria Braithwaite3
1The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States, 2Department of Bioengineering, Pennsylvania State Univesity, University Park, PA, United States, 3The Center for Brain, Behavior, & Cognition, Department of Ecosystem Science & Management, Pennsylvania State University, University Park, PA, United States

 
The zebrafish is widely recognized as a key model organism in developmental and neurobehavioral research, yet very little is known about how housing and handling have an effect on brain development. Zebrafish were reared in four different treatments that varied in their exposure to environmental enrichment and a chronic mild stress (chasing with a net). After 78 days the fish were culled and imaged (14T system, 20microns resolution). The telencephalon (which processes spatial and emotional learning) was segmented. Our study demonstrates that the development of the zebrafish telencephalon is influenced by environmental factors, but is not affected by handling stress.

 
2955.   65 Non-Linear Modeling of T1, T2 and MWF Developmental Trajectories¿
Douglas C. Dean III1, Jonathan O'Muircheartaigh1,2, Lindsay Walker1, Holly Dirks1, Nicole Waskiewicz1, Katie Lehman1, Beth A. Jerskey1,3, and Sean C. L. Deoni1
1Advanced Baby Imaging Lab, School of Engineering, Brown University, Providence, RI, United States, 2Dept. of Neuroimaging Sciences, King's College London, Institute of Psychiatry, London, United Kingdom, 3Dept. Oof Psychiatry & Human Behavior, Brown University, Providence, RI, United States

 
Rapid neurodevelopmental changes can be investigated using magnetic resonance imaging (MRI). An anatomical model of development can be obtained by modeling quantitative maps of healthy infants and toddlers. In this work we modeled regional and whole-brain T1, T2, and MWF maps of healthy children under 5 years of age. This model can be used to characterize normal development and serve as a baseline of typical development.

 
2956.   66 Asymmetry of White Matter Pathways in the Human Brain: Fetal, Neonatal, and Toddler Stages -permission withheld
Jae W. Song1, Paul D. Michell1, James Kolasinski2, Rebecca D. Folkerth3, Patricia Ellen Grant4, Albert M. Galaburda5, and Emi Takahashi1
1Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Massachusetts General Hospital, Boston, MA, United States, 3Brigham and Women's Hospital, Boston, MA, United States, 4Boston Children's Hospital, Boston, MA, United States, 5Beth Israel Deaconess Medical Center, Boston, MA, United States

 
We aimed to describe and quantify emerging asymmetry of white matter pathways including limbic (cingulum, fornix) and association pathways (inferior longitudinal fasciculus [ILF], inferior fronto-occipital fasciculus [IFOF], and arcuate fasciculus [AF]) in fetal, newborn, and children younger than 3 years old, using high angular resolution diffusion imaging tractography. Our results suggest that the ILF compared to the IFOF and AF develops laterality during the early developmental stage before 3 years old. Leftward dominant myelination may proceed in ILF during the early developmental stage, and the development of the IFOF and AF may proceed differentially from that of the ILF.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (11:45-12:45) Exhibition Hall
Advanced Fetal & Pediatric CNS Imaging

  Computer #  
2957.   49 Coupling DTI and Histological Analysis to Examine the Multiple Layers of the Human Fetal Brain Cerebral Wall
Hao Huang1, Tina Jeon1, and Linda J. Richards2
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 2The Queesland Brain Institute, The University of Queesland, Brisbane, Queesland, Australia

 
The cerebral wall of human fetal brain is the place where active molecular and cellular activities take place during 2nd trimester fetal development, resulting in distinctive microstructures in different layers. High contrasts from DTI and histological staining are complementary to provide insight on microstructural configuration of different layers of the cerebral wall. In this study, we coupled quantitative measures from high resolution DTI data from postmortem 2nd trimester human fetal brain DTI and histology stained with hematoxylin or immunohistochemically labeled with anti-glial fibrillary acidic protein and neurofilament antibody. Differential FA values across the cerebral wall layers were quantified.

 
2958.   50 Exploring the Human Fetal Brain Network with Diffusion MRI and Graph Theory
Virendra Mishra1, Ni Shu2, Lina Chalak3, Nancy K. Rollins4, Cathy Halovanic5, Yong He2, and Hao Huang1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, Beijing, China, 3Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States, 4Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 5Children's Medical Center of Dallas, Dallas, TX, United States

 
Characterizing the normal prenatal brain network development will not only expand our understanding of formation of functionally significant brain circuits, but also shed light on understanding the abnormal network development associated with child mental health. However, prenatal brain network development has not been characterized in the literature. In this study, high resolution DTI data of ex vivo fetal brains at 20 weeks of gestation and in vivo neonatal brain at term were acquired. Graph theory analysis was conducted with the brain nodes parcellated from a template free algorithm and edges quantified based on DTI tractography.

 
2959.   51 Reliable Measurement Techniques for Motion Corrected Fetal Brain Volume
Devasuda Anblagan1,2, Kaiming Yin1, Rebecca Reynolds3, Fiona Denison2, Mark E. Bastin4, Colin Studholme5, Jane Norman2, Scott I. Semple1, and Neil Roberts1
1Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, Edinburgh, United Kingdom, 2MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom, 3Centre for Cardiovascular Sciences, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom, 4Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom, 5Department of Pediatrics Neonatology, University of Washington, Seattle, Washington, United States

 
Fetal MRI is increasingly used to study brain development, but is challenging due to fetal motion. While motion correction is now possible with fetal brain, it remains unclear what the ideal segmentation technique is to extract brain structures. Here, we report the practicality, time efficiency and precision of three stereology designs (Isotropic Cavalieri (IsoC), Invariator, and Nucleator) in estimating fetal brain volume on motion-corrected 3D fetal brain images, by comparing corresponding values obtained from the same MR images without motion correction. Our work suggests IsoC is the most precise and time efficient stereology method; Invariator and Nucleator may be convenient.

 
2960.   52 Altered Brain Morphology in Boys with Duchenne Muscular Dystrophy Compared to Healthy Age Matched Controls
Nathalie Doorenweerd1,2, Chiara S.M. Straathof2, Eve M. Dumas2, Beatrijs H.A. Wokke2, Erik H. Niks2, Janneke C. van den Bergen2, Debby G.M. Schrans3, Jos G.M. Hendriksen3, Andrew G. Webb1, Mark A. van Buchem1, Jan J.G.M. Verschuuren2, and Hermien E. Kan1
1Radiology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 2Neurology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 3Department of Neurological Learning Disabilities, Kempenhaeghe Epilepsy Centre, Heeze, Brabant, Netherlands

 
Brain morphology in boys with Duchenne muscular dystrophy (DMD) was studied and compared to healthy age-matched controls. Widespread differences were found such as lower grey matter volume and higher white matter tissue water content in DMD. The global spread of the morphological differences may be related to the (lack of) dystrophin isoforms in the brain in DMD. These data may also provide clues to understanding the etiology of the higher incidence of learning and behavioral problems in DMD.

 
2961.   53 Effects of Propofol on Cerebral Perfusion of White Matter Versus Gray Matter in Pediatric Brain.
Reem S. Awwad1, Wilburn E. Reddick1, Bryan Winter2, Yimei Li2, John O. Glass1, Roland N. Kaddoum3, Zoltan Patay1, Amar Gajjar4, and Julie H. Harreld1
1Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, United States, 2Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, United States, 3Anesthesiology, St. Jude Children's Research Hospital, Memphis, TN, United States, 4Oncology, St. Jude Children's Research Hospital, Memphis, TN, United States

 
We retrospectively reviewed DSC perfusion MRI of normal-appearing brain in 38 children to investigate whether, as in gray matter (GM), white matter (WM) or GM/WM ratios of CBF or CBV differed between propofol-sedated (IV) and non-sedated (NS) children. Differences in WM CBF & CBV between groups were not the same as in GM. CBVGM/WM did not differ between groups. NS CBFGM/WM > IV in PCA territory only. Age- and weight-related trends of all measures differed between groups. CBFGM/WM and CBVGM/WM, though less variable than GM or WM measures alone, should be used with caution, as age-related trends may differ with propofol.

 
2962.   54 The Increased Detectivity of Punctate White Matter Lesions in Neonatal Brains by Using Three-Dimensional High Spatial Resolution T1 Weighted Images
Qinli Sun1, Yumiao Zhang1, Jie Gao1, Jianghong Han1, Bolang Yu1, and Jian Yang1
1Department of Radiology, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shannxi Province, China

 
The purpose in this study is to compare detected numbers of punctate white matter lesion (PWML) between 3D-FSPGR T1WI and other MRI sequences. A total of 294 lesions were detected on 3D-FSPGR T1WI, while only 158, 131, 129, 85, 34 lesions were observed on ADC, T2WI, reconstructed T1WI, magnitude and phase maps respectively. The detectivity of PWML between 3D-FSPGR T1WI and other MR sequences showed significant difference. This study first demonstrates that 3D T1WI is more sensitive in detecting PWML in neonatal brains relative to other MRI sequences. It is greatly recommended to use 3D T1WI as a routine sequence for neonatal brain MR examination.

 
2963.   55 Functional Connectivity Among Resting State Networks Increases After Constraint-Induced Movement Therapy in Children with Brain Injury
Maria A. Rocca1, Sandra Strazzer2, Anna Turconi2, Paola Valsasina1, Martina Absinta1, Elena Beretta2, Monica Cazzagon3, Andrea Falini4, and Massimo Filippi1
1Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy,2Department of Neurology, IRCCS Eugenio Medea, La Nostra Famiglia, Bosisio Parini, LC, Italy, 3Department of Neurology, IRCCS Eugenio Medea, La Nostra Famiglia, Pasian di Prato, UD, Italy, 4Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy

 
From 14 children with acquired or congenital brain injury and 10 sex- and age-matched healthy controls, we acquired resting state (RS) functional MRI data before constraint-induced movement therapy (CIMT) (baseline), at the end of CIMT (week 10) and after 6 months. Functional network connectivity was used to assess significant interactions among resting state networks at baseline, and changes of association between networks at the two follow-up evaluations. Changes of resting state connectivity among sensory, motor and cognitive networks were detected in pediatric patients with chronic hemiplegia after CIMT. Such changes correlated with clinical improvement following treatment.

 
2964.   56 Extreme Prematurity and Intrauterine Growth Restriction Effects in Brain Network Topology at School Age
Elda Fischi-Gomez1,2, Djalel Eddine Meskaldji1, Lana Vasung2, François Lazeyras3,4, Jean-Philippe Thiran1,5, and Petra Susan Hüppi6
1École Polytechnique Fédérale de Lausanne (EPFL), Signal Processing Laboratory 5(LTS5), Lausanne, (VD), Switzerland, 2Division of Development and Growth. Department of Pediatrics. University of Geneva, Geneva, (GE), Switzerland, 3Center for Biomedical Imaging (CIBM), Lausanne and Geneva, Geneva, (GE), Switzerland, 4Department of Radiology, University of Geneva and University Hospital of Geneva, Geneva, (GE), Switzerland, 5Department of Radiology of the University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, (VD), Switzerland, 6University of Geneva, Geneva, (GE), Switzerland

 
In this study, we hypothesized that underlying changes in neurogenesis due to early exposure to environmental factors or due to altered in-utero environment are associated to axonal fiber development and white matter connectivity and organization. Using diffusion MRI-derived brain graphs we studied children born extreme preterm (EP) and born moderate preterm with intra-uterine growth restriction (IUGR) at school age. The localized significant differences found in node degree within some subcortical regions for both groups of subjects and in betweenness centrality in case of EP may suggest a direct link between events occurring in critical developmental periods and specific cognitive capacities.

 
2965.   57 Metabolic and Structural Correlates of Different Patterns of White Matter Injury in Preterm Infants
Ashok Panigrahy1,2, Jessica L. Wisnowski3,4, Rafael C. Ceschin5, and Stefan Bluml2
1Pediatric Radiology, Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States, 2Childrens Hospital Los Angeles, Los Angeles, California, United States,3Pediatric Radiology, Childrens Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States, 4Brain and Creativity Institute, University of Southern California, Los Angeles, California, United States, 5Children's Hospital of Pittsburgh, Pittsburgh, PA, United States

 
We used MRS to examine cerebral metabolism in the parietal white matter of a large cohort of high-risk preterm infants in relation to two MRI defined patterns of white matter injury and present the first evidence of altered NAA/MI ratio, T2 relaxation, and thalamic volume, in association with punctate white lesions, but not diffuse extensive high signal intensity (DESHI)

 
2966.   58 Lactate-Edited MRS in Neonatal Hypoxic Ischemic Encephalopathy
Ruth L. O'Gorman1, Carola Sabandal1, Vera Bernet1, Cornelia Hagmann2, Martin A. Janich3, and Ralph Noeske4
1University Children's Hospital, Zurich, CH, Switzerland, 2University Hospital, Zurich, CH, Switzerland, 3Diagnostics & Biomedical Tech Laboratory, GE Global Research, München, Germany, 4Applied Science Laboratory, GE Healthcare, Berlin, Germany

 
This study investigates the relative sensitivity of lactate editing in comparison to standard PRESS MRS for detecting lactate in neonates with suspected hypoxic ischemic encephalopathy (HIE). Measured lactate concentrations and Lac/NAA ratios were higher for the lactate-edited spectra relative to corresponding values from standard PRESS (TE=35/144 ms). The short TE (35 ms) and lactate-edited spectra show comparable sensitivity to lactate but the specificity and fit reliability was higher for the lactate-edited spectra. Therefore, lactate-edited MRS can improve the specificity and reliability of lactate detection in infants with suspected HIE, particularly in the presence of strong lipid signals.

 
2967.   59 Non-Invasive Assessment of Cerebral Metabolic Rate of Oxygen in Neonates.
Jill Britt De Vis1, Esben Thade Petersen1, Manon J.N.L. Benders2, Petra M.A. Lemmers2, Thomas Alderliesten2, Frank van Bel2, and Jeroen Hendrikse1
1Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Neonatology, Wilhelmina Children's Hospital, Utrecht, Utrecht, Netherlands

 
Evaluation of cerebral metabolic rate of oxygen (CMRO2) in neonates has been hampered due to the invasiveness of the available techniques. Here we propose a technique which enables non-invasive assessment of global CMRO2 in this population. Initial results are promising as we were able to show a decreased CMRO2 in infants diagnosed with asphyxia.

 
2968.   60 Assessment of Structural Connectivity in Congenital Hemiplegia: The Connectome in Unilateral Cerebral Palsy
Kerstin Pannek1, Simon Scheck2, Roslyn Boyd2, and Stephen Rose3
1The University of Queensland, Brisbane, Queensland, Australia, 2The University of Queensland, Brisbane, Australia, 3The Australian E-Health Research Centre, CSIRO, Brisbane, Australia

 
Alterations in connectivity in children with left and right cerebral palsy compared to typically developing children were assessed. Connections with altered FA or MD were identified automatically from the connectome. Only pathways within the ipsilesional hemisphere, and interhemispheric pathways showed reductions in FA and increases in MD compared to typically developing children. In both children with left and right hemiplegia, connections between the motor regions and the brain stem, the thalamus, cerebellum and posterior cingulate were altered, as well as fronto-parietal connections and the interhemispheric motor pathway.

 
2969.   61 Potential of Resting State Connectivity and Passive fMRI to Detect Precursors of Learning Disabilities in Infants: Preliminary Results with Infants at Familial Risk for Developmental Dyslexia
Mathieu Dehaes1,2, Nora M. Raschle1,3, Danielle D. Sliva2, Jennifer Zuk3, Marie Drottar2, Michelle Chang3, Barbara Peysakhovich3, Bryce Becker3, Sara Smith3, Rudolph Pienaar1,2, Nadine Gaab1,3, and Patricia Ellen Grant2,4
1Pediatrics, Harvard Medical School, Boston, MA, United States, 2Newborn Medicine, Boston Children's Hospital, Boston, MA, United States, 3Developmental Medicine, Boston Children's Hospital, Boston, MA, United States, 4Pediatrics, Boston Children's Hospital, Boston, MA, United States

 
Developmental dyslexia (DD) is a specific language-based learning disorder affecting 5-17% of all children, characterized by difficulties with word recognition, poor spelling and decoding. Currently DD can only be diagnosed around 3rd grade, restricting the implementation of early intervention. It remains unclear how early these differences manifest. Functional resting-state connectivity MRI is a safe technique that can reveal resting-state network (RSN). Here we used an independent component analysis to estimate RSNs in infants with and without familial risk for DD at 7-12 months. Results indicate successful detection of RSNs. fMRI maps may be used as seed regions to reveal RSNs.

 
2970.   62 Functional MRI Revealed the Decrease of Working-Memory Capacity and the Impaired Function of Working-Memory Circuits in 22q11.2 Deletion Syndrome
Ling Zou1,2, Waverly Harrel3, Zoe A. Englander4, Micah Johnson2, Allen W. Song2, and Vandana Shashi3
1CMRRC,Radiology Department, West China Hospital, Chengdu, Sichuan, China, 2Duke-UNC Brain Imaging and Analysis Center (BIAC), Duke University Medical Center, Durham, NC, United States, 3Department of Pediatrics, Duke University Medical Center, Durham, NC, United States, 4Duke-UNC Brain Imaging and Analysis Center (BIAC), Duke University, Durham, NC, United States

 
Patients with 22q11.2 deletion have significant neurocognitive deficits. Childhood cognitive difficulties such as working memory (WM) are universal in patients. Structure MRI studies have found multiple brain parenchyma abnormalities, most of which are inside the brain WM circuits. But brain activities under hierarchical WM loads in patients have not been explored so far. In the present study we explored the hierarchical impairment patterns of WM deficits of the disorder using consecutive n-back task based fMRI, which may potentially serve as functional imaging biomarkers of the disorder and contribute to the evaluation of cognitive remediation in patients.

 
2971.   63 Automatic Detection of Primary Motor Cortex and Corticospinal Tract Using Diffusion MRI Tractography: -permission withheld
Jeong-Won Jeong1,2, Eishi Asano1,2, Diane C. Chugani2,3, and Harry T. Chugani2,4
1Pediatrics and Neurology, Wayne State University, Detroit, Michigan, United States, 2PET center, Children's Hospital of Michigan, Detroit, Michigan, United States, 3Pediatrics and Radiology, Wayne State University, Detroit, Michigan, United States, 4Pediatrics, Neurology, and Radiology, Wayne State University, Detroit, Michigan, United States

 
Epilepsy is one of the most common neurologic disorders restricting the quality of life in affected individuals. The current gold standard for identifying primary motor areas in children with epilepsy is electrical stimulation mapping (ESM) which, however, is invasive and often not adequately sensitive in young children. To investigate whether DWI tractography can provide automatic localization of cortical areas and white matter pathways associated with movement of mouth/lip, fingers, and legs, the present study proposed a new method, a maximum a posteriori probability classification using neural connectivity of the cortico-spinal tract between precentral gyrus and posterior limb of internal capsule.

 
2972.   
64 Longitudinal Hippocampal Shape Changes Between Term-Equivalent and 7 Years in Very Preterm and Full-Term Children
Deanne K. Thompson1, Christopher Adamson1, Cristina G. Omizzolo1, Lex W. Doyle2, Gary F. Egan3, Terrie E. Inder4, and Peter J. Anderson1
1Murdoch Childrens Research Institute, Parkville, Victoria, Australia, 2Royal Women's Hospital, Parkville, Victoria, Australia, 3Monash University, Clayton, Victoria, Australia, 4St Louis Children's Hospital, St Louis, Missouri, United States

 
This study is the first to map the early developmental trajectory of regional hippocampal changes between infancy and childhood. Hippocampi were manually traced at term-equivalent and at 7 years on 24 full-term and 119 very preterm subjects. Longitudinal regional changes were observed using the spherical harmonic point distribution model, and a group comparison was made. Both full-term and very preterm infants’ hippocampi undergo infolding or ‘curling up’ between infancy and 7 years. Furthermore, the developmental trajectory of the hippocampus between infancy and 7 years in VPT children differs from that of FT children, particularly for the left side.

 
2973.   65 Localization of Function-Specific Segments of the Primary Motor Pathway in Children with Sturge-Weber Syndrome: A Multimodal Imaging Analysis -permission withheld
Jeong-Won Jeong1, Harry T. Chugani2, and Csaba Juhasz1
1Pediatrics and Neurology, Wayne State University, Detroit, Michigan, United States, 2Pediatrics, Neurology, and Radiology, Wayne State University, Detroit, Michigan, United States

 
Sturge-Weber syndrome is a rare disorder with a variety of nervous system problems, including motor deficit, visual field impairment, cognitive decline and seizures. The degree of motor cortex and corticospinal tract involvement is difficult to determine in children who are unable to cooperate with functional MRI. To investigate whether diffusion weighted imaging tractography can provide a functional localization of primary motor areas in-vivo, we developed a new method based on tract connectivity between precentral gyrus and posterior limb of internal capsule. This can provide localization of functionally specific segments of the primary motor area only by using the tractography information.

 
2974.   66 Reduced Field-Of-View DWI of the Fetal Brain with Adaptive Averaging
Suchandrima Banerjee1, Orit A. Glenn2, Emine U. Saritas3, Xin Mu2, Duan Xu2, Pauline W. Worters1, and Ajit Shankaranarayanan1
1Applied Science Lab, GE Healthcare, Menlo Park, CA, United States, 2University of California San Francisco, San Francisco, California, United States,3Bioengineering, University of California Berkeley, Berkeley, California, United States

 
Diffusion weighted imaging of fetal brain can help in assessment of brain development. Unfortunately, consistent image quality and high spatial resolution is difficult to achieve, even with current state of the art technology. In this work we use a reduced field-of-view (rFOV) technique based on 2D spatially selective RF excitation with the single-shot echo-planar imaging sequence to achieve high resolution in fetal brain DWI with less off-resonance artifacts. We also retrospectively employ adaptive averaging to mitigate fetal motion artifacts. Feasibility study in ten subjects demonstrates that the rFOV technique and adaptive averaging can improve image quality of fetal brain DWI.

 
2975.   67 White Matter Variations Associated with Severity of Punctate White Matter Lesions: Assessment by Diffusion Tensor Imaging Based on Tract-Based Spatial Statistics (TBSS)
Jie Gao1, Xianjun Li1,2, Yumiao Zhang1, Jianghong Han1, Xue Luo1,2, Gang Niu1, Bolang Yu1, Ed X. Wu3, and Jian Yang1,2
1Department of Radiology, The First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi'an, Shannxi, China, 2Biomedical Engineering, School of Life Science and Technology, Xi'an, Shannxi, China, 3Laboratory of Biomedical Imaging and Signal Processing, Hong Kong, Hong Kong SAR, China

 
This DTI study aimed to investigate and document the different white matter (WM) variations due to punctate white matter lesions (PWML) with varying severity using tract-based spatial statistics (TBSS) analysis. 21 normal preterm neonates and 36 preterm neonates with PWML (18 cases in grade I, 7 cases in grade II and 11 cases in grade III) underwent conventional MRI and DTI. The results showed that there were no significant increased or decreased DTI metrics in major WM tracts of PWML neonates of grade I. For grade II, there was decreased fractional anisotropy (FA) in optic radiation (OR), cerebral peduncle (CP), posterior limb of internal capsule (PLIC), splenium of corpus callosum (SCC) and body of corpus callosum (BCC). For grade III, there were decreased FA with increased radial diffusivity (RD) and mean diffusivity (MD) in OR, PLIC, SCC, BCC, genu of corpus callosum (GCC) and external capsule (EC). These findings indicated the different outcomes of neonates associated with specific severity grade in PWML. Further study will be carried out to follow up these neonates.

 
2976.   68 ASL Labeling Efficiency in Healthy Children
Dustin Kenneth Ragan1 and Jose A. Pineda1
1Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States

 
We investigated the reliability of ASL for studies in children. Because children have more rapid hemodynamics than adults, they are potentially susceptible to failure of the labeling process, particularly in neonates.

 
2977.   69 Cerebral Perfusion Levels Reflect White Matter Injury in Preterm Infants
Ruth L. O'Gorman1, Hans Ulrich Bucher2, Brigitte Koller2, Hadwig Speckbacher1, David C. Alsop3,4, Ajit Shankaranarayanan5, Jean-Claude Fauchere2, and Cornelia Hagmann2
1University Children's Hospital, Zurich, CH, Switzerland, 2University Hospital, Zurich, CH, Switzerland, 3Beth Israel Deaconess Medical Center, Boston, MA, United States, 4Harvard Medical School, Boston, MA, United States, 5Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States

 
This study investigates the link between cerebral perfusion and white matter injury in preterm infants. Cerebral perfusion images were acquired using a background suppressed pulsed continuous arterial spin labeling sequence, and white matter injury scores were derived from structural T1- and T2-weighted MRI using a standardized scoring system. The correlation between perfusion and white matter injury was assessed on a voxelwise basis by permutation testing. White matter injury scores were negatively correlated with perfusion in the cerebellum, basal ganglia, and thalamus, suggesting that perfusion may reflect a selective vulnerability to lesions in these areas and in the cerebral white matter.

 
2978.   70 Arterial Spin Labeled Perfusion MRI in Children with Chronic Kidney Disease -permission withheld
Hua-Shan Liu1, Abbas Jawad1, Nina Laney1, Robert Schultz1, Christos Davatzikos1, Divya Moodalbail1, Susan Furth1, and John A. Detre1
1University of Pennsylvania, Philadelphia, Pennsylvania, United States

 
Chronic Kidney Disease (CKD) is associated with systematic changes of physiological factors that can alter cerebral blood flow (CBF) and brain function. In the present study, we demonstrated the feasibility of measuring CBF with arterial spin labeling in pediatric patients with CKD. Our findings indicated that hematocrit is the most significant determinant of CBF changes. A deviation of correlation between age and white matter CBF observed in pediatric CKD patients may reflect developmental changes in regional brain function as compared with control subjects.

 
2979.   71 Evaluation of Multi-Component Diffusion Coeffcients in Pediatric Gliomas
He Wang1, Guang Cao2, Yuhua Li3, and Xiujie Duan3
1MR Research China, GE Healthcare, Shanghai, China, 2GE Healthcare, Shanghai, China, 3Radiology, Xinhua Hospital, Shanghai Jiaotong University, Shanghai, China

 
In this study, detailed diffusion measurements of pediatric glioma using multiple b-factors ranging up to 4000 s/mm2 have been made. 17 children with brain tumors underwent brain MR examinations at 3T scanner. Results showed that the biexponential and stretched-exponential model can all meet the WHO classification of the pediatric gliomas in the brain more accurately than the standard ADC. Multi-exponential diffusion decay functions are required for diffusion signal decay curves when sampled over an extended b-factor range, providing additional, unique tissue characterization parameters for pediatric gliomas in the brain.

 
2980.   
72 Comparison of Three Non-Gaussian Diffusion Models for Differentiation of Pediatric Brain Tumors
Yi Sui1,2, Guanzhong Liu1, He Wang3, Frederick C. Damen1,4, Yuhua Li5, and Xiaohong Joe Zhou1,6
1Center for MR Research, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Applied Science Lab, GE Healthcare, Shanghai, China, 4Department of Radiology, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, 5Department of Radiology, Xinhua Hospital, Shanghai, China, 6Departments of Radiology, Neurosurgery and Bioengineering, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States

 
A systematic comparison of non-Gaussian diffusion models is conducted in the context of differentiating pediatric brain tumors. Three non-Gaussian diffusion models - FROC, kurtosis and bi-exponential models - were selected for evaluation of their performance for differentiating low-grade from high-grade pediatric brain tumors. Our results suggested that FROC model had the best performance, although the other two models also produced excellent results. In conclusion, non-Gaussian diffusion models with high b-values (up to 4000 s/mm2) can provide valuable and reliable information for characterizing pediatric brain tumors.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (10:45-11:45) Exhibition Hall
Neurovascular Diseases

  Computer #  
2981.   73 ex vivo MRI of Carotid Plaque Excised by Endoarterectomy: Correlation Between T1 and Histologically Assessed Age and Degree of Hemorrhage in Lipid Rich Necrotic Core
Naoaki Yamada1, Yoshiaki Morita1, Koji Iihara2, Hatsue Ishibashi-Ueda3, Masahiro Higashi1, and Hiroaki Naito4
1Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Nuerosurgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 3Pathology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 4National Cerebral and Cardiovascular Center, Suita, Osaka, Japan

 
Relationship between high signals on T1-weighted imaging and age of intraplaque hemorrhage is not sufficiently solved. Sixty-four sections from 16 specimens excised by endoarterectomy were studied to compare ex vivo MRI and histology. In the 64 sections, 46 lipid rich necrotic cores (LRNCs) were identified. Ex vivo MRI was performed to make a T1 map on a 1.5 T system. After MRI, the specimens were processed for pathology and stained by HE, MT and Anti-glycopholin A antibody. In the results, T1 of LRNC with chronic hemorrhage was short that was similar to those with recent hemorrhage.

 
2982.   74 Ultrahigh-Resolution 0.11x0.11mm MR Imaging of the Intracranial Atherosclerotic Vessel Wall at 7.0 Tesla
Anja G. van der Kolk1, Jaco J.M. Zwanenburg1, Wim G.M. Spliet2, Fredy Visser1,3, Peter R. Luijten1, and Jeroen Hendrikse1
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands, 3Philips Healthcare, Best, Netherlands

 
Histopathological studies form the basis of our understanding of pathogenesis of atherosclerotic disease. However, they require ex vivo material, obtained by invasive techniques. Using ultrahigh-field 7T MRI, we might have the spatial resolution and high tissue contrast necessary to noninvasively image intracranial atherosclerosis. In this study, 5 Circle-of-Willis specimens were scanned at 7T with a protocol consisting of a 0.11x0.11mm in-plane resolution T1-, T2-, T2*- and PD-weighted sequence, and compared to histological cuts. On MR, several distinct areas could be identified within the atherosclerotic plaques, suggesting a future role of high-resolution 7T MRI for noninvasive assessment of intracranial atherosclerosis.

 
2983.   75 Penumbra-Imaging in Patients with Acute Stroke Using Susceptibility Weighted MR-Imaging -permission withheld
Alexander Radbruch1,2, Johanna Mucke1, Markus Graf2, Ralf Floca2, Matthias Roethke2, Heinz-Peter Schlemmer2, Sabine Heiland1, Martin Bendszus1, and Stefan Rohde1
1Department of Neuroradiology, Heidelberg University Medical Center, Heidelberg, Germany, 2Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

 
The penumbra concept based on MRI diffusion and perfusion imaging is frequently used within clinical practice. However, it has become under debate since perfusion MRI is supposed to overestimate the tissue at risk. Susceptibility Weighted imaging provides an alternative method for penumbra determination due to the appearance of hypointense vessels within the hypoxic area. In our study we compared the penumbra determined by either SWI or time to peak perfusion (TTP) maps and found the penumbra determined on SWI to be significantly smaller than TTP maps (p<0.0001). Hence SWI may determine the penumbra more accurately than TTP maps.

 
2984.   76 Dual Feature Based Receiver Operating Characteristic Analysis for Assessment of Acute Ischemic Stroke -permission withheld
Venkata Veerendranadh Chebrolu1, Suresh E. Joel1, Dattesh D. Shanbhag1, Ananda Narasimha Murthy1, Vivek Vaidya1, Patrice Hervo2, Marc-Antoine Labeyrie3, Catherine Oppenheim3,4, and Rakesh Mullick1
1Medical Image Analysis Lab, GE Global Research, Bangalore, Karnataka, India, 2GE Healthcare, Buc, France, 3Departments of Radiology and Neurology, Centre Hospitalier, Sainte-Anne, Paris, France, 4Université Paris Descartes, Paris, France

 
The classification of cerebral regions into normal and infarcted tissues based on Diffusion weighted imaging (DWI) characteristics plays a critical role in MRI based stroke patient management. The use of both DWI images and Apparent Diffusion Coefficient (ADC) maps may achieve better classification accuracy than using ADC or DWI alone. In this work, we presented a dual feature (ADC and DWI) based Receiver Operating Characteristic analysis and proposed a novel acute ischemic infarct classification criteria. Results demonstrate better agreement with ground-truth using dual features (specificity-98%; sensitivity-60%) as compared to ADC alone based infarct segmentation (specificity-96%; sensitivity-53%) in 65 subjects.

 
2985.   77 T1rho in Acute Cerebral Infarctions
Toshiaki Akashi1, Toshiaki Taoka1, Saeka Hori1, Tomoko Ochi1, Toshiteru Miyasaka1, Masahiko Sakamoto1, Megumi Takewa2, Tomoyuki Okuaki3, and Kimihiko Kichikawa1
1Radiology, Nara Medical University, Kashihara, Nara, Japan, 2Radiology, Heisei Memorial Hospital, Kashihara, Nara, Japan, 3Philips Electronics Japan, Minato-Ku, Tokyo, Japan

 
We evaluated T1rho of acute cerebral infarctions of human. Seven patients with 8 lesions were enrolled. T1rho MRI was acquired by 3.0T clinical scanner (spin lock pulse; 500 Hz for 1, 10, and 80ms). T1rho maps were compared with hyperintense areas on DWI (haDWI). Seven of all showed entirely prolonged T1rho. In 4 of 7 lesions, mild elevation of T1rho was found around haDWI. One cortical lesion showed variable T1rho values, and area with abnormal T1rho was much larger than the haDWI. These mismatches between T1rho map and DWI may indicate penumbra regions or other pathological processes.

 
2986.   78 Studying Brain Motor, Language and Auditory Functions and Associated Functional Connectivity on AVM Patients by fMRI and Resting State fMRI
Bob L. Hou1, Majid Haghighat Ahoar1, Sanjay Bhatia2, Rachel Lagos1, and Jeff S. Carpenter1
1Radiology, WVU, Morgantown, WV, United States, 2Surgery, WVU, Morgantown, WV, United States

 
Arteriovenous malformations (AVM) lesion cause venous hypertension within the draining vein and relative arterial hypotension in the surrounding brain tissue. This steal effect in which high blood volume and low pressure in the feeding arteries create hypoperfusion in surrounding normal brain has been reported to lead to brain functional reorganization. In this study, we investigated brain motor, language and auditory functions and associated functional connectivity for AVM patients by fMRI and resting state fMRI (rfMRI). We hypnotized that this condition results in changes (i.e., reorganization) in brain functions and or in brain functional connectivity

 
2987.   79 in vivo and Ex Vivo Multimodal Characterisation of Human Carotid Artery Atherosclerosis Plaques.
Mohamed Tachrount1, Fiona Kennedy1, David A. Doig1, Matthew Adams1, Tarek A. Yousry1, Xavier Golay2, David L. Thomas1, and Rolf H. Jager1
1Department od brain repair and rehabilitation, UCL Institute of Neurology, London, United Kingdom, 2Department od brain repair and rehabilitation, University College London, London, United Kingdom

 
Plaque ulceration, thrombosis and intraplaque haemorrhage are the main causes of stroke and clinical symptoms of atherosclerosis. In addition to the degree of luminal narrowing, characterisation of the plaque composition and ultrastructure is important for the assessment of stroke risk. Ex vivo MRI at very high magnetic field allows for detailed assessment of the plaques components. In this multimodal study, ex vivo plaque contrast and relaxation characteristics were analysed based on high spatial resolution images and compared to in vivo MRI and CT images.

 
2988.   80 Preoperative Evaluation of the Origins of the Perforating Arteries Using 7T MRI in Patients with Unruptured Aneurysms
Takahiro Koji1, Yoshitaka Kubo1, Toshiyuki Murakami1, Takamasa Nanba1, Makoto Sasaki2, Akira Ogawa1, and Kuniaki Ogasawara1
1Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan, 2Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Morioka, Iwate, Japan

 
This study investigated preoperative evaluation of the origins of the perforating arteries using 7-Tesla magnetic resonance image (7T MRI) in patients with unruptured aneurysms. Six patients underwent 3D time-of-flight spoiled gradient echo MRA (3D-TOF MRA) at 7T MR imager before surgery. In three of these 6 patients, relationship of the origins of the perforating arteries to the aneurysms was clearly displayed on the MRA. The relationship on the MRA corresponded with findings of intraoperative view through microscope. 3D-TOF MRA on 7T MR imager can evaluate relationship of the origins of the perforating arteries to the aneurysms.

 
2989.   81 The Value of Vessel-Encoded Pseudocontinuous Arterial Spin Labelling (VEPCASL) in Perfusion Assessment of Brain Arteriovenous Malformations: Comparison with Dynamic Susceptibility Contrast (DSC)-MRI
Meritxell Garcia1,2, Monika Gloor3, Michael A. Chappell4,5, Peter Jezzard5, James V. Byrne2, Oliver Bieri3, and Thomas W. Okell5
1Division of Diagnostic & Interventional Neuroradiology, Department of Radiology, Clinic of Radiology & Nuclear Medicine, University of Basel Hospital, Basel, Switzerland, 2Nuffield Department of Surgical Sciences and Department of Neuroradiology, University of Oxford, Oxford, United Kingdom, 3Division of Radiological Physics, Department of Medical Radiology, University of Basel Hospital, Basel, Switzerland, 4Institute of Biomedical Engineering, Department of Engineering, University of Oxford, Oxford, United Kingdom, 5Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, Oxford, United Kingdom

 
The efficacy of quantitative Vessel-Encoded Pseudocontinuous Arterial Spin Labelling (VEPCASL) in the assessment of regional perfusion alterations in arteriovenous malformations (AVMs) was analysed. VEPCASL perfusion was compared with Dynamic Susceptibility Contrast MRI (DSC-MRI). The lack of a need for contrast agent, lower data variation, and absent sensitivity to distortion artefacts makes ASL superior to DSC-MRI for perfusion assessment in AVMs. The ability to label different vascular territories separately with VEPCASL may be of significant use in the determination of perfusion normalisation between treatment stages. Different perfusion patterns in different AVM subtypes can be explained by differences in abnormal vessel composition.

 
2990.   
82 Brain Plasticity Changes in Motor Region and Dynamic Changes in White Matter After Stroke Induced by a Neural Activity-Triggered Rehabilitation Device
Jie Song1, Leo Walton2, Brittany Young2, Veena A. Nair3, Svyat Vergun4, HuiChun Chen5, Dorothy Farrar-Edwards5, Mitch E. Tyler1, Justin Sattin6, Justin C. Williams1, and Vivek Prabhakaran3
1Biomedical Engineering, UW-Madison, Madison, WI, United States, 2Neuroscience Training Program, UW-Madison, Madison, WI, United States, 3Radiology, UW-Madison, Madison, WI, United States, 4Medical Physics, UW-Madison, Madison, WI, United States, 5Kinesiology, UW-Madison, Madison, WI, United States, 6Neurology, UW-Madison, UW-Madison, WI, United States

 
We investigate a closed-loop neurological feedback device which combines Brain computer interface-EEG and functional electrical muscle stimulation together with tongue stimulation and combines the subject’s intention-to-move with the stimulated output thus providing patients with both visual and sensory feedback and direct control of the stimulus intensity. We use fMRI and DTI to elucidate the neural mechanisms by which the training with this device can facilitate brain reorganization and white matter change leading to greater functional recovery.

 
2991.   83 Measurement of Hemodynamic Parameters in Carotid Occlusive Disease Using Partial Volume Corrected PCASL fMRI
Iris Asllani1, Shazia Dharssi1, Marykay Pavol1, Ronald L. Lazar1, and Randolph S. Marshall1
1Columbia University, New York, NY, United States

 
There is converging evidence that cerebral hemodynamic failure affects cognitive function in carotid artery disease, but inconsistent methods of measuring both the behavioral and the hemodynamic state have hindered this line of inquiry from influencing clinical management. Here, we present preliminary data from patients with 100% carotid stenosis on whom we measured hemodynamic parameters such as baseline and activation CBF as well as arterial transit times (ATT) using PCASL fMRI.

 
2992.   84 Cerebral Hemodynamics Evaluation by ACZ Challenge DSC-MRI with VOF Rescaling Scheme
Shogo Oda1, Keiichi Kikuchi2, Kohsuke Kudo3, Yoshiyasu Hiratsuka2, Hitoshi Miki1, Teruhito Mochizuki2, Hideaki Watanabe4, and Yoshiaki Kumon4
1Radiology, Ehime Prefectual Central Hospital, Matsuyama, Ehime, Japan, 2Radiology, Ehime University School of Medicine, Toon City, Ehime, Japan,3Advanced Medical Science Center, Iwate Medical University, Morioka, Iwate, Japan, 4Neurosurgery, Ehime University School of Medicine, Toon City, Ehime, Japan

 
Evaluation of cerebral vascular reactivity with acetazolamide challenge DSC-MRI

 
2993.   85 High Resolution 3D Intracranial ASL Angiography Using Automatically Tuned Compressed Sensing
Huimin Wu1, Walter F. Block1,2, Patrick Turski3, Charles A. Mistretta1, and Kevin M. Johnson1
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 3Radiology, University of Wisconsin-Madison, Madison, WI, United States

 
Fully 3D compressed sensing was implemented with iterative soft thresholding (IST) and used for reconstruction of 3D intracranial angiograms obtained with PCASL-VIPR. A data-driven threshold selection method based on SURE (Stein’s Unbiased Risk Estimator) was utilized at each iteration to adaptively calculate the threshold. Standard non-iterative reconstruction, auto-tuned CS and manually tuned CS were compared on a static PCASL-VIPR dataset with an isotropic resolution of 0.43 mm. CS was able to greatly improve the SNR and vessel visualization with acceleration as high as 20X without manual parameter tuning.

 
2994.   86 Quantification of Macro- And Micro-Vascular Hemodynamics in Cerebral Arteriovenous Malformations During Staged Embolization
Can Wu1, Timothy J. Carroll1, Parmede Vakil1, Sameer A. Ansari2, Bernard R. Bendok2, Hunt Batjer3, and Michael Markl1
1Departments of Biomedical Engineering and Radiology, Northwestern University, Chicago, IL, United States, 2Departments of Radiology and Neurological Surgery, Northwestern University, Chicago, IL, United States, 3Department of Neurological Surgery, UT Southwestern, Dallas, TX, United States

 
4D flow and perfusion MRI were successfully employed to provide quantitative information on both macro- and micro-vascular hemodynamics in AVM patients during embolization. Schematic AVM models were built for macrovascular flow quantification. Contralateral and ipsilateral tissue perfusion was quantified to evaluate the impact of embolization on systemic hemodynamic changes. Spatial co-registration of the 4D flow and perfusion data provides a joint visualization of macrovascular 3D blood flow and microvascular tissue perfusion. The results demonstrate the potential of the joint 4D flow-perfusion MRI method for AVM pre-treatment planning and post-treatment evaluation.

 
2995.   87 MRI/A in the Evaluation of Changes Over Time in Untreated Aneuryms
David A. Saloner1, Alastair Martin2, Daniel Hurwit2, Sahand Sohrabi2, Andrew Lee2, Vitaliy L. Rayz2, William Young3, Wade Smith4, Randall Higashida2, Michael Lawton5, and Charles McCulloch6
1Radiology and Biomedical Imaging, VAMC/UCSF, San Francisco, CA, United States, 2Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 3Anesthesiology, UCSF, San Francisco, CA, United States, 4Neurology, UCSF, San Francisco, CA, United States, 5Neurological Surgery, UCSF, San Francisco, CA, United States, 6Epidemiology and Biostatistics, UCSF, San Francisco, CA, United States

 
This study reports on the serial imaging of subjects with untreated intracranial aneurysms. 74 aneurysms in 68 patients were thrombus-free and studies were conducted over a total of 226 intervals. The standard error of measurement was found to be 4.9%. Approximately 15% of aneurysms were found to grow over time.

 
2996.   88 A Parse-MRI Based Technique to Measure Cerebral Oxygen Extraction Fraction (OEF)
Rajiv G. Menon1, Edward G. Walsh2, Donald B. Twieg3, and Timothy J. Carroll1,4
1Radiology Department, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 2Neuroscience, Brown University, Providence, Rhode Island, United States, 3Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States, 4Biomedical Engineering, Northwestern University, Chicago, IL, United States

 
Oxygen extraction fraction (OEF) is shown to be an independent predictor of stroke. There is an unmet clinical need for a robust MR based OEF measurement technique. A novel PARSE (Parameter Assessment by Retrieval from Signal Encoding) MRI based technique is reported here to measure OEF. We tested the technique on 5 normal subjects and provide anecdotal evidence on an AVM (Arterio-Venous Malformation) patient. Calculated PARSE MR-OEF correlate well with published Positron Emission Tomography (PET) data. Further clinical validation on subjects is required to establish the efficacy of this technique to clinically diagnose stroke risk in a patient.

 
2997.   89 Mild Hypercapnia Causes a Measurable Change in Cerebral Oxygen Extraction Fraction (OEF)
Rajiv G. Menon1, Charles G. Cantrell1, Edward G. Walsh2, Donald B. Twieg3, and Timothy J. Carroll1
1Radiology Department, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 2Neuroscience, Brown University, Providence, Rhode Island, United States, 3Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States

 
OEF(Oxygen Extraction Fraction) is shown to be an independent predictor of stroke We previously reported an MR technique to measure OEF. Here we show that we can measure dynamic changes in OEF (OEF Reactivity) by inducing mild hypercapnia using a breath-hold experiment. We tested the method on 5 normal volunteers and demonstrate that we can measure OEF changes related to mild physiologic stress. OEF reactivity as a surrogate measure of cerebrovascular reserve would provide supplemental information in patients who receive diamox/acetazolamide challenge to determine information on collateralization, and correlate with more favorable outcomes in revascularization therapy.

 
2998.   90 Noncontrast Enhanced MRA with Compressed Sensing and Parallel Imaging for Evaluation of Branches of the Aortic Arch -permission withheld
Takayuki Masui1, Motoyuki Katayama1, Koji Yoneyama1, Masayoshi Sugimura1, Naoyuki Takei2, Kimihiko Sato1, Kei Tsukamoto1, Kenichi Mizuki1, and Hiroyuki Kabasawa2
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, 2GE Healthcare Japan, Hino, Tokyo, Japan

 
Noncontrast enhanced (NC)-MRA with inflow inversion recovery technique, IFIR FSE can be obtained for the evaluation of the arteries from the aortic arch to the skull base using peripheral pulse gating at 3T in combined use of compressed sensing and parallel imaging ARC. This technique may be used as a screening method covering the wide areas of the arteries within an acceptable short imaging time and image quality in the patients with cerebral vascular diseases. In those cases, robust imaging parameters have to be applied for stable NC-MRAs.

 
2999.   91 Diffusion Tensor and Volumetric Magnetic Resonance Imaging Using an MR Compatible Rehabilitation Hand Device Suggests Training-Induced Neuroplasticity in Chronic Stroke
Asimina Lazaridou1,2, Loukas Astrakas1,2, Dionyssios Mintzopoulos1,2, Azadeh Khanicheh3, Aneesh Singhal4, Michael Moskowitz2, Bruce Rosen2, and Aria A. Tzika1,2
1NMR Surgical Laboratory, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, MA, United States, 2Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States, 3Mechanical Engineering, Northeastern University, Boston, MA, United States, 4Department of Neurology, Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States

 
A large proportion of the focus of stroke research remains on novel rehabilitation interventions. Using volumetric and diffusion tensor imaging (DTI) at 3T in conjunction with a novel MR-compatible hand-induced robotic device (MR_CHIROD) we investigated neuroplasticity in chronic stroke by probing structural changes. New CST fiber tracts projecting progressively closer to motor cortex indicated structural neuroplasticity. Volumetric imaging showed significant increase in the cortical thickness of the ventral postcentral gyrus areas. The results demonstrate the potential of training-induced neuroplasticity in chronic stroke, where stroke rehabilitation is relatively new, having suffered from the longstanding view that lost functions were not recoverable.

 
3000.   92 Segmentation-Based Quantification of Brain SWI for Predicting the Stroke Evolution
Ping-Huei Tsai1,2, Chia-Yuen Chen2, Chin-I Chen3, Fong Y. Tsai1, Hsiao-Wen Chung4, and Wing P. Chan2
1Imaging Research Center, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, 3Department of Neurology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, 4Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan

 
The aim of this study is using an auto segmentation method based on data clustering to investigate the symmetry of brain SWI in normal subjects and facilitate the quantification of the asymmetric distribution of the deoxygenated vessels in patients with acute ischemic stroke for a better prediction of the evolution. Our preliminary finding demonstrates that the proposed method provides objective information for evaluation of the patients, and may have a potential to contribute to determining the penumbra and predicting of the stroke prognosis, as well as the following treatment.

 
3001.   93 Comprehensive Assessment of Cerebral Hemodynamic Parameters (Y, CVR, CBF, OEF and CMRO2) and Perfusion Territories for Patients with Cerebrovascular Disease.
Jill Britt De Vis1, Jeroen Hendrikse1, and Esben Thade Petersen1
1Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

 
In patients with cerebrovascular disease outcome can be predicted by evaluating hemodynamic parameters. Here we present a comprehensive protocol designed to evaluate all hemodynamic parameters.

 
3002.   94 Magnetic Resonance PWI-Derived Collateral Flow Index Is a Predictor of MCA-M1 Recanalization After Iv Thrombolysis : New Insight Using the Bayesian Method
Francois Nicoli1, Timothe Boutelier2, Fabrice Pautot2, and Nadine Girard3
1Medical Affairs, Olea Medical, La Ciotat, Bouches du Rhone, France, 2Research & Innovation, Olea Medical, La Ciotat, Bouches du Rhone, France,3Neuroradiology, La Timone University Hospital, Marseille, Bouches du Rhone, France

 
Recently, an index of collateral flow that is predictive of the rate of recanalization of MCA-M1 occlusions in patients treated with IV Thrombolysis (IVT) has been described. This index, named the normalized Collateral Circulation Deficit (nCCD), is based on Tmax maps at different time points (calculated using a block-circulant SVD). To confirm that the nCCD index determined using cSVD is significantly correlated with the speed of the supplying flow inside the MCA territory, we performed a Bayesian estimation of hemodynamic parameters in a cohort of patients with an acute MCA-M1 occlusion. The Bayesian method (BM) is a rigorous probabilistic estimation of hemodynamic parameters. From a quantitative point of view, this method outperforms deconvolution methods (standard, block-circulant or oscillating SVD).

 
3003.   95 Quantitative Evaluation of Mismatch in Recanalized Acute Stroke Patients: Comparison Between Arterial Spin Labeling and Dynamic Susceptibility Contrast Perfusion
Kambiz Nael1, Arash Meshksar1, Benjamin Ellingson2, Pablo J. Villablanca2, and Noriko Salamon2
1Medical Imaging, University of Arizona, Tucson, AZ, United States, 2Radiological Sciences, UCLA, Los Angeles, CA, United States

 
Using a pseudo-continuous ASL with background suppression and a 2 second post-labeling delay, ASL performs with only moderate agreement with DSC in quantitative assessment of mismatch classification in revascularized patients with acute stroke. In particular ASL appears less sensitive for detection of reperfusion in successfully recanalized patients. Since the cerebral hemodynamics and arterial arrival time are different in pre and post revascularized patients, different post-labeling delay or ASL methods independent of arterial arrival time (velocity selective ASL) may be needed for better evaluation.

 
3004.   96 Correlation of MR Image Features and Hemorrhagic Transformation in Acute Cerebral Infarction: A Multi-Modal Study -permission withheld
Jun Liu1, Liang Xu1, Chunming Liu1, and Zhengchao Dong2,3
1Union Medical Center, Tianjin, Tianjin, China, 2Columbia University, New York, NY, United States, 3New York State of Psychiatric Institute, New York, NY, United States

 
Early prediction of Hemorrhagic transformation (HT) of acute cerebral infarction is crucially important but is very difficult due to the rapid development and the complexities of the pathophysiology of the disease. In this communication, we report a multimodal MRI approach to studying the HT in acute cerebral infarction. Our fundamental hypothesis is that each modality of the MRI techniques provide complimentary information about HT; by applying multimodal MRI techniques in a synergetic way, we would be able to obtain a stereoscopic picture of the HT and, thereby, to improve the prediction of HT in cerebral infarction.

 

ELECTRONIC POSTER SESSION • NEURO A
Monday, 22 April 2013 (11:45-12:45) Exhibition Hall
High Resolution Brain Anatomy & Morphology

  Computer #  
3005.   73 in vivo Identification of Human Optic Radiation and Stria of Gennari Using High-Resolution Phase Difference Enhanced Imaging at 3 Tesla
Li Yang1, Guangbin Wang1, Lili Li1, Queenie Chan2, and Weibo Chen3
1Shandong Medical Imaging Research Institute, Jinan, Shandong, China, 2Philips Healthcare, Hongkong, Hongkong, China, 3Philips Healthcare, Shanghai, Shanghai, China

 
Phase difference enhanced (PADRE) imaging technique uses three-dimensional (3D) principle of echo shifting with a train of observations (PRESTO) which can selectively enhance the phase difference between the targets and surrounding tissue. Our purpose is to evaluate the findings of the optic radiation and the myelinated layers in striate cortex (stria of Gennari) in vivo using PADRE and measure the phase values in optic radiation and striate cortex.The PADRE technique can differentiate the two layers of the optic radiation and identify the stria of Gennari, which, at least in part, seems to be associated with differential myelin content.

 
3006.   74 A Computer-Aided Detection of Cerebral Microbleeds on Minimum Intensity Projection MR Images of SWI
Wei Bian1,2, Christopher P. Hess2, Susan M. Chang3, Sarah J. Nelson1,2, and Janine M. Lupo2
1Graduate Program in Bioengineering, University of California San Francisco & Berkeley, San Francisco, CA, United States, 2Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3Neurological Surgery, University of California San Francisco, San Francisco, CA, United States

 
A computer-aided method is proposed to identify cerebral microbleeds on minimum intensity projected susceptibility-weighted MR images. It utilizes the 2D fast radial symmetry transform to initially detect nearly all possible putative CMBs. False positives are subsequently eliminated by examining geometric features measured after performing 3D region growing on the putative CMBs. The performance of the method was evaluated on 15 patients with total 420 CMBs induced by radiation treatment for resected gliomas. The evaluation showed that our method achieved a detection sensitivity of 88.3% using only 1 minute computation, which is much more sensitive and faster than previously published methods.

 
3007.   75 Atypical Sulcal Patterns in Pre-Readers and Beginning Readers with a Familial Risk for Developmental Dyslexia
Kiho Im1, Nora M. Raschle1, Jennifer Zuk1, Jennifer Minas2, Ola Ozranov-Palchik1, Nadine Gaab1, and Patricia Ellen Grant3
1Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Massachusetts Institute of Technology, Cambridge, MA, United States,3Boston Children's Hospital, Boston, MA, United States

 
Developmental dyslexia (DD) is one of the most prominent specific learning disabilities, affecting 5-17% of children. The goal of this study was to investigate possible structural pre-markers of DD in pre-readers as well as beginning readers using sulcal pattern analysis.

 
3008.   76 Dependence of R1 on Tissue Microstructure: A Group Study of 100 Subjects
Martina F. Callaghan1, Antoine Lutti1, Siawoosh Mohammadi1, and Nikolaus Weiskopf1
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom

 
Quantitative MRI aims to produce measurements of diagnostic value that are independent of scanner and acquisition protocol. Biophysical models can provide validation for these markers and bring us a step closer to accessing important biological parameters in vivo that are normally only available post mortem. We explored the validity of using quantitative transverse relaxation rate and magnetisation transfer maps as markers for macromolecular and iron content in a linear model of longitudinal relaxation rate in 100 subjects. The linear model fit with a high Pearson coefficient and exhibited stability in the coefficients across the large cohort.

 
3009.   77 High Quality Whole Brain MP2RAGE at 7T: Utilization of Thin Dielectric Pads
Kieran O'Brien1, Tobias Kober2, Jose Marques3, François Lazeyras1, Rolf Gruetter1,4, and Gunnar Krueger2
1CIBM, University of Geneva, Geneva, Switzerland, 2Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, 3CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne & Univertisy of Lausanne, Lausanne, Switzerland, 4CIBM-AIT, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

 
At ultra high fields (>3T), whole brain 3D MP2RAGE acquisition suffer from poor inversion in the Cerebellum. In particular, when a subject’s head size is large relative to the physical “z” coverage of the transmit coil, the radiofrequency (RF) power available is not sufficient to overcome the adiabatic condition. Introducing thin dielectric pads enables the RF distribution’s hot spot to be redistributed towards the cerebellum. This improves the RF power and ensures better inversion efficiency enabling high quality whole brain coverage in 3D MP2RAGE scans for all subjects to be obtained.

 
3010.   78 High-Resolution MRI of Persistent Metopic Suture
Martin Krämer1, Karl-Heinz Herrmann1, Martin Stenzel2, Hans-Joachim Mentzel2, and Jürgen R. Reichenbach1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany,2Pediatric Radiology, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

 
We report of a rare case of a persistent metopic suture in an adult male which was imaged using high resolution gradient echo magnetic resonance imaging. A curved surface reconstruction was performed along the cranial surface for an improved visualization of the suture. Although very rare clinicians and radiologists should be aware of this condition in order to avoid misdiagnoses, for example as vertical facture.

 
3011.   79 Longitudinal VBM of Regional Progression in Human Prion Disease -permission withheld
Enrico De Vita1,2, Harpreet Hyare3,4, Gerard R. Ridgway5, Marie-Claire Porter3,4, Andrew Thompson3,4, Chris Carswell3,4, Ana Lukic3,4, Rolf H. Jager1,2, Diana Caine3,4, Peter Rudge3,4, Tarek A. Yousry1,2, John Collinge3,4, Simon Mead3,4, and John Thornton1,2
1Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, United Kingdom,2Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 3MRC Prion Unit, Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, United Kingdom, 4National Prion Clinic, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, United Kingdom, 5Wellcome Department of Cognitive Neurology, UCL Institute of Neurology, London, United Kingdom

 
Human prion diseases (transmissible spongiform encephalopathies) are progressive and fatal neurodegenerative disorders. Voxel based morphometry (VBM) has only been used to study prion disease pathology in cross sectional studies. Only whole-brain summary measures have been employed to assess progressive degeneration longitudinally. Here we followed up a large numbr of prion disease patients with serial cerebral MRI and applied longitudinal VBM to characterize progressive structural change. We reveal significant regional changes in brain atrophy in prion patients consistent with known prion pathology and show correlation of rates of structural change with change in clinical assessment scores.

 
3012.   
80 in vivo 7T Imaging of Nigrosome Loss in Parkinson’s Disease
Anna I. Blazejewska1, Stefan T. Schwarz2, Alain Pitiot3, Mary C. Stephenson1, James Lowe4, Nin Bajaj5, Richard W. Bowtell1, Dorothee P. Auer2, and Penelope A. Gowland1
1SPMMRC, University of Nottingham, Nottingham, Notts, United Kingdom, 2Division of Radiological and Imaging Sciences, University of Nottingham, Nottingham, Notts, United Kingdom, 3School of Psychology, University of Nottingham, Nottingham, Notts, United Kingdom, 4Division of Pathology, Nottingham University Hospitals NHS Trust, Nottingham, Notts, United Kingdom, 5Division of Neurology, Nottingham University Hospitals NHS Trust, Nottingham, Notts, United Kingdom

 
Parkinson’s disease (PD) is caused by loss of dopaminergic cells particularly from the nigrosomes of the substantia nigra pars compacta (SNpc). In this study we correlated in vivo, post mortem MRI and histochemical data proving the ability of high resolution 7T MRI imaging to directly visualise nigrosome 1. Further assessment of T2*w scans of PD patients versus healthy controls by the neurologists suggested that the absence of nigrosome 1 in the SNpc on MR scans may provide a neuroimaging diagnostic test for the Parkinson's disease.

 
3013.   81 An Image Searching Engine to Utilize Past Clinical Data for the Future Diagnosis
Andreia V. Faria1, Shoko Yoshida1, Kenichi Oishi1, Kanako Sato1, Argye Hillis2, MIchael I. Miller3, and Susumu Mori1
1Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Neurology, Johns Hopkins Hospital, Baltimore, MD, United States, 3Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States

 
We report our attempt to develop a technology to structurize image features and facilitate image searching. The structurization was based on automated parcellation of the entire brain into 211 structures using T1-WIs and high-dimensional normalization method. We tested if the structurized anatomical data actually captured the anatomical features in a population with atrophy at different degrees and locations by comparing the results with trained clinicians evaluation. We explored the data and tested individual classifications using PCA and discriminant analysis. The structurization of image data through image-vector conversion was effective, and provides opportunities to mine clinical database for medical decision support

 
3014.   82 Improved Longitudinal Gray Matter Atrophy Assessment Via a Combination of SIENA and a 4-Dimensional Hidden Markov Random Field Model
Michael G. Dwyer1, Niels P. Bergsland1, and Robert Zivadinov1
1Buffalo Neuroimaging Analysis Center, University at Buffalo, Buffalo, NY, United States

 
We describe a novel technique for substantially improving the reliability of longitudinal gray matter atrophy measurement through the extension of SIENAX’s hidden Markov random field model from 3 dimensions to 4. We validate our approach using both simulation and real clinical data, and show a marked improvement in effect size and statistical power.

 
3015.   83 A Robust Brain Segmentation of Multispectral MRI Using a Supervised Hybrid Classifier
Jyh-Wen Chai1,2, Clayton Chi-Chang Chen3, Hsian-Min Chen4, Yi-Ying Wu1, Pei-Hua Lo1, Chu-Jing Song1, Yi-Hsin Tsai2, San-Kan Lee3, Yen-Chien Ouyang5, and Chein-I Chang6
1Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan, Taiwan, 2College of Medicine, China Medical University, Taichung, Taiwan, Taiwan, 3Taichung Veterans General Hospital, Taichung, Taiwan, Taiwan, 4Department of Biomedical Engineering, HungKuang University, Taichung, Taiwan, Taiwan, 5Department of Electrical Engineering, National Chung Hsin University, Taichung, Taiwan, Taiwan, 6Department of Computer Science and Electrical Engineering, University of Maryland, Baltimore, Baltimore, MD, United States

 
With no need of a prior knowledge about the tissue intensity or anatomical information, the supervised hybrid classifier was utilized for tissue classification of multispectral MRI in the native coordinate space by using only one small set of training samples. The preliminary results demonstrated that the proposed method can perform an accurate and reproducible brain volume morphometry of multispectral 3D high spatial resolution MRI in synthetic image data and in different groups of human subjects. This supervised method has shown potential in clinical applications, particularly promising for longitudinal studies of brain morphometry with multispectral MRI.

 
3016.   84 High Resolution Imaging of the Hippocampus with Spatially Selective Excitation and a Reduced FOV Readout at 7T
Ronald Mooiweer1, Alessandro Sbrizzi1, Fredy Visser1,2, Cornelis A.T. van den Berg1, Peter R. Luijten1, and Hans Hoogduin1
1UMC Utrecht, Utrecht, Utrecht, Netherlands, 2Philips Healthcare, Best, Noord-Brabant, Netherlands

 
High resolution T2* weighted images of the hippocampal formation are presented using spatially selective excitation combined with a reduced FOV readout at 7T.

 
3017.   85 Aging of the Central Nervous System: A Voxel-Based Quantification (VBQ) Study of 100 Volunteers
Martina F. Callaghan1, Patrick Freund1,2, Bogdan Draganski3, Marinella Cappelletti1, Thomas Fitzgerald1, Peter Smittenaar1, Antoine Lutti1, and Nikolaus Weiskopf1
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 2Spinal Cord Injury Center Balgrist, University Hospital Zurich, Zurich, Switzerland, 3LREN, Department des Neurosciences Cliniques, CHUV, Universite de Lausanne, Lausanne, Switzerland

 
Quantitative MR parameters reflect changes occurring in tissue on a microstructural level. We acquired quantitative maps of longitudinal relaxation rate (R1), transverse relaxation rate (R2*) and magnetisation transfer (MT) from a population of 100 healthy volunteers with an age range of 18-74 years. Voxel-based statistical analysis of the whole brain, incorporating spinal cord metrics, identified changes significantly correlated with age consistent with changes in myelination and iron content known to occur on a microstructural level during aging. Robust quantitative mapping will be of great benefit for establishing normative parameter values and gaining insight into the underlying causes of pathological conditions.

 
3018.   86 Optimally-Discriminative Voxel-Based Morphometry Significantly Increases the Ability to Detect Group Differences in Schizophrenia, Mild Cognitive Impairment, and Alzheimer’s Disease
Tianhao Zhang1 and Christos Davatzikos1
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

 
Voxel-Based Morphometry (VBM) has been widely applied for characterizing brain changes on structural Magnetic Resonance Imaging. However in the conventional VBM methods, Gaussian smoothing, which is always used prior to General Linear Model (GLM) to integrate imaging signals from a region, proves critical due to lack of the spatial adaptivity necessary to optimally match image filtering with an underlying region of interest. In this work, Optimally-Discriminative Voxel-Based Analysis (ODVBA), as a recently-developed method utilizing a new spatially adaptive smoothing scheme to determine group differences, is evaluated in comparison with the conventional VBM method, two other spatially adaptive smoothing methods, and two cluster enhancing methods, in three studies on schizophrenia, mild cognitive impairment, and Alzheimer’s disease.

 
3019.   87 Associating Neuropsychological Deficits with Decreased Gray and White Matter Density in Alcohol Dependents: A Voxel Based Morphometric Analysis Using DARTEL
Deepika Bagga1, Namita Singh1, Shilpi Modi1, Prabhjot Kaur1, Debajyoti Bhattacharya2, Mohan Lal Garg3, and subash khushu1
1NMR Research Centre, INMAS, New Delhi, New Delhi, India, 2Department of psychiatry, Base Hospital, New Delhi, New Delhi, India, 3Department of Biophysics, Panjab University, chandigarh, chandigarh, India

 
Chronic alcoholism leads to a number of transient or persistent neurological and psychiatric deficits. The aim of our study was to associate the cognitive deficits observed in visuospatial information processing as assessed by PGIBBD (PGI-Battery of Brain Dysfunction) in alcohol dependents with the brain morphometry changes and duration of alcohol consumption. To that end, VBM analysis was carried out in alcohol dependents and healthy controls. Significant gray and white matter volume loss in fronto-parietal regions was observed which could account for the impaired visuospatial information processing skills in alcohol dependents.

 
3020.   88 WITHDRAWN
 
3021.   89 Practical Quantitative Zoomed DTI of Medial Temporal Lobe Structures Using a 2-Channel Parallel Transmit Coil.
Timothy M. Shepherd1, Christopher B. Glielmi2, Christian Geppert3, and Josef Pfeuffer4
1Radiology, NYU Langone Medical Center, New York, NY, United States, 2Siemens Medical Solutions, New York, NY, United States, 3Siemens Medical Systems, New York, NY, United States, 4Siemens Healthcare, Erlangen, Germany

 
This presentation describes using 2D-selective RF excitation with a 2-channel parallel transmit coil to obtain zoomed DTI for interrogating diffusion and functional connectivity within the medial temporal lobe structures.

 
3022.   90 Diffusion Imaging of Post-Mortem Human Brains: DW-SSFP at 7T Provides Improved Crossing Fibre Estimates
Sean Foxley1, Saad Jbabdi1, Wilfred Lam1, and Karla Miller1
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom

 
Post-mortem human brain imaging is of interest both to validate in-vivo measures and to scan for long periods of time to achieve high spatial resolution. Use of diffusion weighted steady-state free precession (DW-SSFP) has been demonstrated to perform significantly better than diffusion-weighted spin echo techniques for post-mortem human brain tractography at 3T. However limitations in SNR have made voxel-by-voxel secondary fibre population estimation difficult. This indicates worse contrast-to-noise ratio than what is currently used for in-vivo protocols. In this work we explore DW-SSFP at 7T with two different beff values to investigate potential improvements in secondary fibre estimations.

 
3023.   91 in vivo Ultra-High Resolution Diffusion Tensor Imaging of the Medial Temporal Lobe in Patients with Epilepsy
Mansi B. Parekh1, Robert Fisher2, Kevin Graber2, Ryan Purcell3, Rishi Raman3, Leandro Bouzon3, Scott Atlas1, Samantha J. Holdsworth1, Stefan Skare1, Rolland Bammer1, and Michael Zeineh1
1Radiology, Stanford University, Stanford, California, United States, 2Neurology & Neurological Sciences, Stanford University, Stanford, California, United States, 3Stanford University, Stanford, California, United States

 
Discerning the microstructural abnormalities of the epileptogenic focus are not always possible with conventional MRI in patients with epilepsy. However, ultra-high resolution diffusion tensor imaging (DTI) may provide adequate microanatomical information to study subtle structural changes that underlie the epileptogenic focus. Recent published work from our group has shown promise in being able to study the mesial temporal lobe (MTL) structures using DTI. In this study, we further study fractional anisotropy, mean diffusivity and connectivity changes in the MTL structures of patients with unilateral mesial temporal sclerosis.

 
3024.   92 Structural Contrast Enhancements by Novel Way to Combine T1- And T2-Weighted MR Images
Masaya Misaki1, Jonathan Savitz1,2, Vadim Zotev1, Raquel Phillips1, Han Yuan1, Kymberly D. Young1, Wayne C. Drevets1, and Jerzy Bodurka1,3
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Tulsa School of Community Medicine, University of Tulsa, Tulsa, OK, United States,3College of Engineering, University of Oklahoma, Tulsa, OK, United States

 
We propose a new structural image contrast from a novel combination of T1- and T2-weighted images. A specific combination of T1 and T2 images, CI=(T1-T2)/(T1+T2), could reduce noise and enhance contrast between brain structures. The utility of the new contrast image was evaluated using automatic segmentation software: FAST in FSL for white and gray matter segmentation and FreeSurfer for segmenting subcortical regions. The combined image had significantly higher contrast between white and gray matters as well as between subcortical structures. The contrast enhancement offered by the combined image can improve accuracy of structural analysis of the human brain.

 
3025.   93 Multispectral Fusion-Based Detection of Virchow-Robin Spaces
Vikas Kotari1 and Vasiliki N. Ikonomidou2
1Electrical Engineering, George Mason University, Fairfax, Virginia, United States, 2Bioengineering, George Mason University, Fairfax, Virginia, United States

 
Virchow-Robin spaces are perivascular structures whose dilation can be a biomarker of microvascular disease, vascular dementia, hypertension etc; therefore their detection and characterization may prove useful for disease monitoring. In this study, we present a novel automatic detection technique for VRS detection based on multispectral fusion of information derived from a combination of MPRAGE and T2 weighted images. The approach minimizes noise-driven false positives, resulting in high sensitivity and specificity. The technique is fast and fully automated, making it appropriate for routine use.

 
3026.   94 Confounds in Image Registration
Sune Darkner1, Matthew George Liptrot1, and Jon Sporring1
1Department of Computer Science, University of Copenhagen, Copenhagen, Copenhagen, Denmark

 
Many of the analysis methods applied to neuroimaging are dependent upon correct co-registration of datasets. The direction in which the registration is applied (image A registered to image B, or vice-versa) may vary depending upon the topic of interest without consideration of possible confounds this may involve. Here we show how even affine registration is subject to “inverse inconsistency”, where the co-registration result is different depending upon the direction chosen. A difference of 0.5 voxels is demonstrated for a pure translational, affine registration. Care must therefore be taken when performing co-registration in order to minimize subsequent directionality-based confounds.

 
3027.   95 MRI Texture Spectral Similarity Detects White Matter Microstructure as Compared with Diffusion Tensor Imaging
Yunyan Zhang1, Lenora Brown1, and Luanne M. Metz1
1University of Calgary, Calgary, AB, Canada

 
T2-weighted MRI and DTI were performed in the white matter of five healthy volunteers. Fractional anisotropy (FA), radial and axial diffusivity were computed in 4 brain regions. Using T2 MRI, texture spectral similarity that dictates inter-voxel relationships was computed based on polar Stockwell transform. The genu and splenium of the corpus callosum demonstrated greater FA, axial diffusivity, and texture dissimilarity than the other structures, opposite to the pattern of radial diffusivity. With equivalent power to DTI indices, texture spectral similarity may be a sensitive measure of white matter architecture based on conventional MRI and embedded into clinical practice.

 
3028.   96 Voxel Misassignments and Their Consequences in DTI Skeleton-Based Group Analyses
Michael Bach1,2, Bram Stieltjes1, Frederik B. Laun1,2, Alexander Leemans3, and Klaus Hermann Fritzsche1,4
1Quantitative Imaging-based Disease Characterization, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Dpt. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 4Medical Imaging and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany

 
Considering the widespread and growing use of tract-based spatial statistics (TBSS), it is important to fully understand the potential limitations of this approach. In this work the voxels of the cingulum bundle (CB) and corpus callosum (CC) are followed up through the TBSS-process. Our results reveal that CB voxels are assigned to the CC-skeleton and vice versa. This strongly influences the statistical inference, as shown here for a group comparison between 15 Alzheimer’s diseases patients and 15 healthy controls. In conclusion the potential misassignment of adjacent white matter tracts must be born in mind when interpreting TBBS results.