Amritha Nayak^1,2, Angela Bissoli³, Okan M Irfanoglu², Guiseppe Ricciardi³, Elisa Ciceri³, and Carlo Pierpaoli Pierpaoli^2
1Henry Jackson Foundation for advancement in Military Medicine Inc, Rockville, MD, United States, ²National Insitutes of Health, Bethesda, MD, United States, ³Azienda Ospedaliera Universitaria Integrata, Verona, Italy

This study evaluates the role of a high quality DTI in presurgical planning of MRgFUS for initial target localization.
 

Chao Wang¹, Shuyue Wang¹, Peiyu Huang¹, and Minming Zhang^1
1Department of Radiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China

 The insula, a cortical region that is thought to play a central role in this reward circuitry, has been implicated as an important role in the maintenance of nicotine addiction. However, it remains largely unclear about the alterations in white-matter tracts of insula circuits in nicotine addiction. Here, we further investigated the differences of insula white-matter tracts between smokers and nonsmokers. We found abnormal white matter tracts of insula subregions in smokers. These altered insula microstructural connectivity could interfere with the normal neural circuitry of reward processing, which might be the underlying neurobiology of nicotine addiction.

Lu Wang¹, Hing-Chiu Chang¹, Peng Cao¹, and Edward.S Hui^1
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China

In this study we acquired diffusion data and motor functions from stroke patients at within 1 week, 1, 3 and 6 months and found rich-club organization remerged one month after stroke and high order regions were found at 6 months when patients functionally recovered. Feeder connections showed middle cost and high capacity while rich-club connections showed high cost and middle capacity at 6 months after stroke. Together these results suggest that there could be a potential relation between reemergence of rich-club organization and brain motor recovery.

Gizem Temiz¹, Sophie Sébille¹, Chantal François¹, Eric Bardinet¹, and Carine Karachi^1,2
1CENIR, Institut du Cerveau et de la Moelle Epinière, Paris, France, ²AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Neurosurgery, Paris, France, Paris, France

The aim of this study is to analyze differences in the hyperdirect cortical connectivity between the subthalamic nucleus and its medial region, and the anatomo-functional organization of these regions using tractography. These analyzes were performed in healthy subjects and parkinsonian patients. Our results show that a dominant motor cluster was located in the posterolateral STN, a limbic cluster located medially in the MSR, and an intermediate motor-limbic cluster located in between for both cohorts. In conclusion, tractography based sub-parcellisation of subthalamic regions could be helpful to refine individual targeting for functional neurosurgery.

Junqi Xu¹, He Wang^1,2, Xueying Zhao¹, Hui Zhang¹, Xiaoyuan Feng³, and Ren Yan^3
1Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China, ²Human Phenome Institute, Fudan University, Shanghai, China, ³Radiology, Huashan Hospital, Fudan University, Shanghai, China

To offer a potential multiparameter-mapping platform for clinical pathological diagnosis using multi-diffusion models including mono-exponentional model, IVIM, SEM, FROC, CTRW, SM and DKI. The U-test and ROC analysis show the superiority of FROC, CTRW and DKI models in diagnostic accuracy for grading brain tumors (at 0.770, 0.780 and 0.817 respectively).

Julio Ernesto Villalon Reina¹, Talia Miriam Nir², Sophia Thomopoulos², Lauren E Salminen³, Neda M Jahanshad², Rutger Fick⁴, Matteo Frigo⁵, Rachid Deriche⁵, and Paul M Thompson^2
1USC Imaging Genetics Center, University of Southern California, Los Angeles, CA, United States, ²USC Stevens Neuroimaging and Informatics Institute, University of Southern California, Marina del Rey, CA, United States, ³USC Imaging Genetics Center, University of Southern California, Marina del Rey, CA, United States, ⁴Therapanacea, Paris, France, ⁵Athena Project Team, Inria Sophia-Antipolis Méditerranée, Université Côte d'Azur, Nice, France

To identify microstructure-based biomarkers sensitive to cognitive impairment, we used ADNI-3 multi-shell dMRI data to estimate 18 measures from seven dMRI models and assessed their ability to predict mild cognitive impairment (MCI). For each measure, we used TV-L1 regularized logistic regression to find cohesive clusters of brain tissue that contribute to correct classification. We found that tensor-based (DTI) diffusivity and multi-compartment spherical mean technique (MC-SMT) measures showed the highest prediction accuracy, but differential anatomical distributions of classifying voxels. MC-SMT may offer greater sensitivity and specificity to MCI than DTI as MC-SMT resulted in the highest recall and fewest classifying voxels.

Timo Roine^1,2, Oskari Kantonen³, Ulrika Roine¹, Sami Virtanen⁴, Jani Saunavaara^4,5, Riitta Parkkola⁴, Ruut Laitio⁶, Olli Arola⁶, Marja Hynninen⁷, Juha Martola⁸, Heli M Silvennoinen⁸, Marjaana Tiainen⁹, Risto O. Roine¹⁰, Harry Scheinin⁶, and Timo Laitio^6
1Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland, ²Turku Brain and Mind Center, University of Turku, Turku, Finland, ³Turku PET Centre, University of Turku and the Hospital District of Southwest Finland, Turku, Finland, ⁴Department of Radiology, Turku University Hospital, University of Turku, Turku, Finland, ⁵Department of Medical Physics, Turku University Hospital, University of Turku, Turku, Finland, ⁶Division of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, University of Turku, Turku, Finland, ⁷Division of Intensive Care Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, ⁸Department of Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, ⁹Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, ¹⁰Division of Clinical Neurosciences, Turku University Hospital, University of Turku, Turku, Finland

Mortality after out-of-hospital cardiac arrest is high, and there is a substantial need for new biomarkers to improve the identification of patients with poor outcome. Therefore, we investigated structural brain connectivity networks in patients after out-of-hospital cardiac arrest in order to detect differences related to survival. We found decreased global efficiency and strength from MRI scans acquired in a median of 53 hours (IQR 47-64) after OHCA to be related to mortality at 6 months after OHCA. In addition, several regions with decreased strength and local efficiency were found, most significantly in the pallidum, and superior frontal and supramarginal cortices.

Steven Jilings¹, Angelique Van Ombergen², Elena Tomilovskaya³, Alena Rumshiskaya⁴, Liudmila Litvinova⁴, Inna Nosikova³, Ekaterina Pechenkova⁵, Ilya Rukavishnikov³, Inessa Kozlovskaya³, Stefan Sunaert⁶, Paul M Parizel⁷, Valentin Sinitsyn⁸, Victor Petrovichev⁴, Steven Laureys⁹, Peter zu Eulenburg¹⁰, Jan Sijbers¹¹, Floris Wuyts¹, and Ben Jeurissen^11
1Lab for Equilibrium Investigations and Aerospace, Dept. of Physics, University of Antwerp, Antwerp, Belgium, ²Translations Neuroscience, Dept. of Medicine, University of Antwerp, Antwerp, Belgium, ³Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russian Federation, ⁴Dept. of Radiology, Federal Center of Treatment and Rehabilitation, Moscow, Russian Federation, ⁵Laboratory for Cognitive Research, National Research University Higher School of Economics, Moscow, Russian Federation, ⁶Dept. of Imaging and Pathology, KU Leuven, Leuven, Belgium, ⁷Dept. of Radiology, Royal Perth Hospital and University of Western Australia, Perth, Australia, ⁸Faculty of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russian Federation, ⁹Coma Science Group, Dept. of Neurology, University (Hospital) of Liège, Liège, Belgium, ¹⁰German Center for Vertigo and Balance Disorders, Dept. of Neurology, Ludwig-Maximilians-University Munich, Munich, Germany, ¹¹imec - Vision Lab, Dept. of Physics, University of Antwerp, Antwerp, Belgium

There is currently limited information on the effects of spaceflight on the human brain. Therefore, we investigated longitudinal changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) density and mass using diffusion MRI data acquired pre-flight, post-flight and at follow-up. Our results show redistributed CSF and concomitant GM morphological changes post-flight, which reverse at follow-up. At the same time, our results show no evidence of neurodegeneration. Moreover, GM and WM mass increased in sensorimotor brain regions post-flight, which largely persisted at follow-up. These results indicate, for the first time, sensorimotor neuroplasticity after spaceflight. 

Jieying Zhang¹, Chunjie Guo², Xinrui Liu³, Yishi Wang^1,4, Huimao Zhang², and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, ²Department of Radiology, the First Hospital of Jilin University, Changchun, China, ³Department of Neurosurgery, the First Hospital of Jilin University, Changchun, China, ⁴Philips Healthcare, Beijing, China

Differentiation between pituitary adenomas (PAs) and Rathke cleft cysts (RCCs) is important for treatment planning. Diffusion weighted imaging (DWI) has been reported for the differentiation. However, traditional single-shot echo planar imaging (EPI) DWI has limited resolution and suffers from image distortion near the skull base. High-resolution distortion-free DWI should be more suitable. We apply a recently developed fast point-spread-function encoded EPI on pituitary imaging. It generates high-resolution distortion-free DWI, in which the signals of the microadenoma and the RCCs are hyperintense and hypointense, respectively. This study shows the potential of this technique to distinguish between PAs and RCCs.

Graham A. D. Archibald¹, Jordan A. Chad^1,2, David H. Salat^3,4, and J. Jean Chen^1,2
1Rotman Research Institute, Baycrest Health Sciences, Toronto, ON, Canada, ²Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ³MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, ⁴Neuroimaging Research for Veterans Center, VA Boston Healthcare System, Boston, MA, United States

The aging process in the cerebral cortex is typically measured in-vivo via MRI-based cortical thickness. Here we show that mean diffusivity (MD), a parameter derived from diffusion MRI, serves as a more sensitive measure of aging than thickness across the cortex. MD shows distinct age-related differences than thickness, suggesting that MD can provide insight into microscopic degeneration that cannot be detected with macroscopic structural MRI measures. While diffusion MRI microstructural analyses are typically limited to the white matter, this work suggests that additionally assessing age-related differences in cortical gray matter diffusivity can offer potentially valuable information on early cortical degeneration.

Madeleine T Dacey^1,2,3, Stefan E Poirier^1,3, Janice Gomes^2,4, Udunna C Anazodo^1,3, and Christopher W McIntyre^1,2
1Medical Biophysics, Western University, London, ON, Canada, ²Kidney Clinical Research Unit, Lawson Health Sciences Center, London, ON, Canada, ³Imaging, Lawson Health Research Insitute, London, ON, Canada, ⁴Pathology and Laboratory Medicine, Western University, London, ON, Canada

Cognitive impairment and white matter degeneration are common in hemodialysis patients. Hemodialysis can severely impede blood flow and create osmotic imbalances in the brain. This may cause brain injury by a mechanism similar to that of stroke. To investigate the acute effects of hemodialysis on the brain, we used a novel system to perform diffusion and T1 weighted MRI scans during hemodialysis. Several tracts exhibit diffusion tensor imaging markers for cytotoxic and ionic edema. Increased white and grey matter volume during hemodialysis further support the presence of ionic edema. Ionic and cytotoxic edema are evidence of acute brain injury.

Scott Kolbe¹, Meaghan Clough¹, Frederique Boonstra¹, Myrte Strik², Anneke van der Walt¹, Helmut Butzkueven¹, Owen White¹, Joanne Fielding¹, and Meng Law^1
1Monash University, Prahran, Australia, ²University of Melbourne, Parkville, Australia

Brain atrophy is currently the accepted method for measuring neurodegeneration in multiple sclerosis (MS) but is insensitive over short times and ignores changes in cellular density. Recent advances in diffusion weighted imaging provide markers of axonal fibre density and atrophy. This study aimed to study the longitudinal sensitivity of these markers in comparison to brain atrophy based on data acquired in a standard clinical MS study. Annualised within-patient change in fibre density was around seven times more sensitive than brain volume change. This supports the development of fibre density based methods for clinical monitoring of axonal loss in MS.

Shana Black^1,2, Andrew Janson^1,2, and Christopher R Butson^1,2,3
1Biomedical Engineering, University of Utah, Salt Lake City, UT, United States, ²Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States, ³Neurology, Neurosurgery, and Psychiatry, University of Utah, Salt Lake City, UT, United States

Fiber-specific white matter changes were compared using fixel-based analysis between spinal cord injured subjects with chronic neuropathic pain (n=17) and spinal cord injured subjects without any pain symptoms (n=15). Fiber density, fiber cross-section (FC), and a combined measurement of fiber density and cross section (FDC) were calculated and compared between groups using multi-shell, 3-tissue constrained spherical deconvolution and connectivity-based fixel enhancement. Statistically significant increases (FWE-corrected p<0.1) in FC and FDC were identified in a posterior-inferior commissural white matter pathway, corresponding to the splenium and major forceps of the corpus callosum and regions of the retrosplenial complex.

XiaoQiang Du¹, YunJing Xue¹, HuaJun Chen¹, and ZhongShuai Zhang^2
1Fujian Medical University Union Hospital, Fuzhou, China, ²SIEMENS Healthcare, Shanghai, China

This study used atlas-based region of interest analysis to assess WM microstructure in ALS by combining intra-voxel metrics, which included FA and MD, and an inter-voxel metric, i.e., LDH. We found WM abnormalities extending from the motor to the extra-motor regions in ALS and observed a correlation between distinct diffusion metrics and various clinical variables, supporting DTI metrics may be utilized as the diagnostic biomarker of ALS. Meanwhile, the extent of WM abnormalities in several tracts (e.g. ATR and LIFOF) were better revealed by LDH measurement, suggesting the supplementary role in reflecting ALS-related pathological process.

Bhaswati Roy¹, Sarah E Choi², Milena Lai³, Luke Ehlert³, Rashmi Mullur⁴, Matthew J. Freeby⁴, and Rajesh Kumar^3,5,6,7
1University of California at Los Angeles, LOS ANGELES, CA, United States, ²UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA, United States, ³Anesthesiology, University of California at Los Angeles, Los Angeles, CA, United States, ⁴Medicine, University of California at Los Angeles, Los Angeles, CA, United States, ⁵Radiology, University of California at Los Angeles, Los Angeles, CA, United States, ⁶Bioengineering, University of California at Los Angeles, Los Angeles, CA, United States, ⁷Brain Research Institute, University of California at Los Angeles, Los Angeles, CA, United States

Patients with Type 2 diabetes mellitus (T2DM) show brain tissue changes in mood and cognitive control sites, functions that are deficient in the condition. However, the nature and extent of brain injury in T2DM, and their progression with time along with functional deficits are unclear. Using diffusion tensor imaging based MD procedures, we showed wide-spread chronic tissue changes in T2DM subjects and their continued progression after 6 months follow-up in areas involve in mood and cognitive regulatory functions. These findings may have resulted from underlying metabolic dysfunction associated with the condition.

Maurizio Bergamino¹, Ashley Nespodzany¹, Leslie C Baxter^1,2, Anna Burke³, Richard Caselli², Marwan N Sabbagh⁴, Ryan R Walsh⁵, and Ashley M Stokes^1
1Division of Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, ²Mayo Clinic Arizona, Phoenix, AZ, United States, ³Department of Neuropsychiatry, Barrow Neurological Institute, Phoenix, AZ, United States, ⁴Lou Ruvo Center for Brain Health, Cleveland Clinic, Las Vegas, NV, United States, ⁵The Muhammad Ali Parkinson Center, Barrow Neurological Institute, Phoenix, AZ, United States

The objective of this study was to assess complementary metrics from voxel-based morphometry (VBM) and intravoxel incoherent motion diffusion-weighted images (IVIM-DWI) MRI methods in aging populations. Using voxel-based analysis, grey matter (GM) and white matter (WM) differences were analyzed across Alzheimer’s disease (AD), mild cognitive impairment (MCI), and cognitively normal (HC) individuals. IVIM-DWI demonstrated early significant differences between MCI and HC groups, while VBM did not. In addition, voxel-based correlations between neuroimaging metrics and cognitive assessments were assessed in the cognitively impaired groups (AD and MCI).

Yaru Sheng¹, Yan Sha¹, Rujian Hong¹, Zhongshuai Zhang², and Wenhu Huang^1
1Radiology, EENT Hospital of Fudan University, Shanghai, China, ²Siemens Healthcare, Shanghai, China

This study aimed to compare the performance of readout-segmented echo-planar imaging (RESOLVE) DWI and delayed gadolinium-enhanced T1-weighted MRI to diagnose cholesteatoma on 531 patients. The results showed that RESOLVE DWI can be an excellent tool for the detection of primary cholesteatoma. 

Benjamin T Newman^1,2, Ana Untaroiu¹, and T. Jason Druzgal^1,2
1Department of Radiology & Medical Imaging, Division of Neuroradiology, University of Virginia Health System, University of Virginia, Charlottesville, VA, United States, ²Brain Institute, University of Virginia, Charlottesville, VA, United States

We propose the use of the NTU-DSI-122 template as a flexible, diffusion specific, means of registering subject images to stereotaxic MNI-space for further analysis. This allows for registration to be performed based on matching white matter fiber orientation distributions, which create within tissue contrasts, unlike voxel intensity metrics. This advantage is demonstrated by observing the increased consistency of registration versus a leading intensity-based algorithm. The range of b-values present in the NTU-DSI-122 allows for tailoring to selectively register at b-values matching those acquired in an experimental cohort, providing flexibility for both single- and multi-shell acquisitions. 

Enping Lin¹, Yu Yang¹, Yuqing Huang¹, and Zhong Chen^1
1Department of Electronic Science, Xiamen University, Xiamen, China

DOSY (Diffusion-ordered NMR spectroscopy) presents an essential tool for the analysis of compound mixtures. However, existing DOSY reconstruction methods is limited by its relatively low resolution. Here, based on constraints on low rank and sparsity of DOSY data, we propose a reconstruction method to achieve high-resolution DOSY spectrum for measurements on complex mixtures, even when component signals are congested and mixed together along the spectral dimension. Experiment results indicate that our method is robust and possesses high-resolution reconstruction performance.

Chun-Xia Li¹, Yumei Yan¹, Longchuan Li², Todd Preuss³, James G Herndon³, Xiaoping Hu⁴, and Xiaodong Zhang^1,3
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, ²Department of Pediatric, Emory University School of Medicine, Atlanta, GA, United States, ³Division of Neuroscience and Neurological diseases, Emory University, Atlanta, GA, United States, ⁴Department of bioengineering, University of California, Riverside, Riverside, CA, United States

Aging effects on the optic nerve (ON) bundles of chimpanzees were investigated systematically with diffusion tensor imaging (DTI). Mean diffusivity (MD), axial diffusivity (AD or λ_ll), radial diffusivity (RD or λ_τ) and fractional anisotropy (FA) showed mild and proportional changes from youth to elder adulthood, and significant increase of MD and RD were seen in elder chimpanzees. However, the changes are much milder than previous studies in the ON of monkey and human brain white matter. The unique evolution pattern in chimpanzee white mater aging may grant further investigations to unveil the neural substrate mechanism of the human brain aging. 

Jeff A Stainsby¹, Chad T Harris¹, Andrew T Curtis¹, Philip J Beatty¹, and Curtis N Wiens^1
1Synaptive Medical, Toronto, ON, Canada

The feasibility of generating diffusion tractography from data obtained on a head-only 0.5T system is demonstrated and results are compared qualitatively to tractography generated from clinical 1.5T data. DTI data from 0.5T compares favorably in quantitative (FA, ADC) measures to literature values, and qualitative (segmented white matter tracts) measures to 1.5T.

Tiago Timoteo Fernandes¹, Marc Golub¹, Andreia Freitas¹, Sairam Geethanath^2,3, and Rita Gouveia Nunes^1
1ISR, IST - University of Lisbon, Lisbon, Portugal, ²Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore, India, ³Magnetic Resonance Research Center, Columbia University, NY, DC, United States

The primary goal of MR in acute stroke imaging  is to determine the ischemic tissue at risk. Since a narrow time window is available for treatment, an accessible point-of-care system is desirable. Ultra-low field MR (ULF) shows promise but suffers from low signal-to-noise ratios (SNR). We performed a theoretical study of the SNR and contrast-to-noise (CNR) ratios for a range of B0 fields, with corresponding tissue relaxation times, considering different gradient performances. Illustrative simulated DWI brain images are provided. Results suggest that despite the challenges, ULF is promising for imaging acute stroke lesions.

Jin Gao^1,2, Zachery Morrissey³, Alex Leow³, Orly Lazarov⁴, Danilo Erricolo¹, Richard Magin⁵, and Weiguo Li^2,5
1Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL, United States, ²Research Resources Center, University of Illinois at Chicago, Chicago, IL, United States, ³Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States, ⁴Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States, ⁵Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States

Alzheimer’s disease (AD) has a tremendous impact in terms of social and economic cost. White matter damage in the progression of AD and the associated cognitive symptoms and pathophysiology are of crucial interest. Diffusion MRI offers unique insights into the pathophysiology of AD in vivo. This feasibility study aims to assess and visualize the white matter changes using an ultrahigh b-value diffusion MRI.

Koji Sakai¹, Jun Tazoe¹, Kentaro Akazawa¹, Hiroyasu Ikeno², Toshiaki Nakagawa², and Kei Yamada^1
1Kyoto Prefectural University of Medicine, Kyoto, Japan, ²Kyoto Prefectural University of Medicine Hospital, Kyoto, Japan

Diffusion-weighted imaging (DWI) based thermometry has the potential to be a non-invasive method of temperature measurement for the deep inside of human brain. Nevertheless, the DWI at lateral ventricle in brain might be influenced by the pulsation flow of cerebrospinal fluid (CSF), which is motivated by heartbeat. The purpose of this study was to investigate the influence of pulsation flow on brain DWI thermometry for healthy subjects. Comparisons were performed between magnetic resonance spectroscopy and DWI based thermometry (ΔT) at three CSF speed selections. There was no significant difference on ΔT among the CSF speed and volume on healthy subjects.

Zhangxuan Hu¹, Zhe Zhang², Yishi Wang³, Yajing Zhang⁴, and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, ²China National Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ³Philips Healthcare, Beijing, China, ⁴MR Clinical Science, Philips Healthcare (Suzhou), Suzhou, China

MRI examinations usually contain multi-contrast images, which may share redundant information. For example, T2w-FLAIR contrast relies on the property of T2 relaxation and water component of the tissue, which also present in T2- and diffusion-weighted images. T2w-FLAIR acquisition is usually lengthy due to the long inversion time. In this study, point-spread-function (PSF) encoded EPI (PSF-EPI) DWI and T2-weighted images were used to generate T2w-FLAIR images by taking the advantages of high-resolution and distortion-free of PSF-EPI. This method has the potential to improve the acquisition efficiency of MRI.

Álvaro Planchuelo-Gómez¹, Rodrigo de Luis-García¹, Antonio Tristán-Vega¹, David García-Azorín², Ángel Luis Guerrero², and Santiago Aja-Fernández^1
1Imaging Processing Laboratory, Universidad de Valladolid, Valladolid, Spain, ²Headache Unit, Hospital Clínico Universitario de Valladolid, Valladolid, Spain

AMURA (Apparent Measures Using Reduced Acquisitions) is an alternative formulation to drastically reduce the number of samples needed for the estimation of diffusion properties related to the Ensemble Average diffusion Propagator (EAP). Although these measures were initially intended for medium-to-high b-values, in this work we evaluate their performance in DTI-like acquisitions. Fifty healthy controls, 54 episodic migraine (EM) and 56 chronic migraine (CM) patients were compared, using a single-shell diffusion scheme at b=1000 s/mm2. We compare AMURA measures (return-to-origin, return-to-axis and return-to-plane probabilities) to traditional DTI measures. Differences between EM and controls were only detectable using the return-to-origin probability.

Álvaro Planchuelo-Gómez¹, Santiago Aja-Fernández¹, David García-Azorín², Ángel Luis Guerrero², and Rodrigo de Luis-García^1
1Imaging Processing Laboratory, Universidad de Valladolid, Valladolid, Spain, ²Headache Unit, Hospital Clínico Universitario de Valladolid, Valladolid, Spain

The effect of changes in the acquisition parameters on Diffusion Tensor Imaging (DTI) has been studied, but for very specific situations. A whole-brain comparison of 54 episodic migraine (EM) and 56 chronic migraine (CM) patients, using diffusion schemes of 61, 40 and 21 gradient orientations, was performed. Statistical comparisons were repeated reducing the sample size until no significant differences were found. Higher number of regions with significant lower axial diffusivity in CM compared to EM were found using 61 gradient directions. With a larger sample size, results with 40 and 21 directions were equivalent to results acquired with 61 directions.

Huiqin Zhang¹, Hui Zhang¹, Franki Kai-Hei Tse ², Edward Sai-Kam Hui¹, Peng Cao¹, Kannie Wai Yan Chan³, Queenie Chan⁴, Karl HERRUP⁵, and Henry Ka Fung Mak^1
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, ²Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, Hong Kong, ³Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, Hong Kong, ⁴Philips Healthcare, Hong Kong, Hong Kong, ⁵Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States

Demyelination is a known pathology in AD, but it is unclear whether such myelin loss resembles primary or secondary demyelinating disease. Here, we retrospectively analysed the DTI data using voxel-wise TBSS analysis and made pair-wise comparisons between cohorts of AD, Relapsing-remitting MS(RRMS), NPSLE and normal controls (NC). In diffusion metrics analysis, widespread microstructural patterns were similarly found between AD and MS in terms of diffusion metrics, but not between AD and NPSLE. Our results indicate that the microstructural WM changes in AD may share similar pathological mechanisms in demyelinating disease of RRMS.

Jung-Sen Hsiao¹, Hung-Yu Fu¹, Pei-Lun Yu¹, Sheng-Min Huang¹, Kung-Chu Ho², and Fu-Nien Wang^1
1Biomedical Engineering and Envionmental Sciences, National Tsing-Hua University, Hsinchu City, Taiwan, ²Chang-Gung Memorial Hospital, Taoyuan City, Taiwan

Diffusion MRI has been regarded as an assessment in characterizing brain tissue integrity. However, the information of tissue heterogeneity is often overlooked. To investigate the feasibility of diffusional heterogeneity in gray matter through DKI derived diffusivities, six spontaneously-hypertensive rats (SHR) in different ages were scanned on a 7T small animal MR scanner. The differences of heterogeneity of diffusivities and kurtosis between different ages were revealed, which may imply its possibility for tissue characterization. Therefore, the diffusional heterogeneity could be suggested to be a potential image-based biomarker for evaluating tissue integrity.

Ethan A Cook¹, Shannon E Callen², Shilpa Buch², and Balasrinivasa R Sajja^3
1College of Medicine, University of Nebraska Medical Center, Omaha, NE, United States, ²Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States, ³Radiology, University of Nebraska Medical Center, Omaha, NE, United States

In vivo imaging-based biomarkers that can accurately detect the brain structural and functional changes due to chronic drug abuse play a significant role to understand and assess brain damage due to cocaine abuse and to determine the efficacy of the treatment. To this end, we have demonstrated that diffusion tensor MRI could detect brain structural changes, particularly demyelination in white matter structures, in chronic cocaine administered mice.

Kei Kikuchi¹, Minghui Tang², Ikuhiro Kida³, and Toru Yamamoto^2
1Graduate School of Health Sciences, Hokkaido University, Sapporo, Japan, ²Faculty of Health Sciences, Hokkaido University, Sapporo, Japan, ³National Institute of Information and Communications Technology, Osaka, Japan

Oxygen molecule is paramagnetic and its relaxation-time-shortening effect is strongly enhanced in viscous intracellular environment following the BPP theory. Therefore, DWI signal, which enhances intercellular signal, could reflect oxygen concentration changes in the cell. To verify this property, we formulated an equation of MR signal that includes signal increase/decrease by T1/T2 shortening by oxygen; there exists a TE (TE₀) at which the relaxation-time-shortening effect counterbalances showing no signal change. We obtained successive DWI signal of brain under resting-state, and observed the existence of TE₀ supporting that intracellular oxygen concentration changes are visible in DWI signal.  

Junxia Wang¹, Sichu Wu², Jilei Zhang³, and Bing Zhang^2
1Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China, ²Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China, ³Clinical Science, Philips Healthcare, Shanghai, Shanghai, China

We used voxel-based independent sample t-test to investigate differences of DKI and resting-state fMRI parametric maps between KIBRA rs17070145 polymorphism in 163 young adults. Mediation analysis was used to explore the association between the KIBRA polymorphism, brain and working memory. We observed that KIBRA C-allele carriers had increased AD, RD, MD and decreased FA, MK, RK, ALFF compared with KIBRA TT homozygotes. The MK, RK of the left precuneus mediated the association between the KIBRA polymorphism and the working memory performance. These findings may be useful in understanding the neural mechanisms of KIBRA and provide a biological pathway of gene-brain-behavior.

Bing Yao^1,2, Hannah Ovadia¹, Gail Forrest³, and Steven Kirshblum^2,4
1Rocco Ortenzio Neuroimaging Center, Kessler Foundation, West Orange, NJ, United States, ²Department of Physical Medicine and Rehabilitation, Rutgers University, Newark, NJ, United States, ³Center for Mobility and Rehabilitation Engineering Research, Kessler Foundation, West Orange, NJ, United States, ⁴Kessler Institute for Rehabilitation, West Orange, NJ, United States

Physicians rely on self-reports to monitor and evaluate the functional outcome in patients with spinal cord injury during their rehabilitation. These clinical and outcome measurements can be subjective and sometimes impractical if patients have cognitive difficulty. Traditional clinical MRI scans can provide doctors more objective information but they are not sensitive to detect the progression or repair during patient’s recovery. In this study, we investigated the sensitivity of DTI technique in detecting SCI injury and its progression or recovery over the course of rehabilitation in the individuals with SCI.

Bing Liu^1,2, Xiangtao Lin^1,2, Peng Zhao¹, Xianshun Yuan^1,2, Mengxiao Liu³, Xiang Feng⁴, Lei Xue⁵, Mimi Tian², Shuai Zhang^1,2, Dejuan Shan^1,2, and Xiaoli Li^1,2
1Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China, ²Shandong University, Jinan, China, ³MR Scientific Marketing, Diagnostic Imaging, Siemens Healthcare Ltd, Shanghai, China, ⁴MR Scientific Marketing, Diagnostic Imaging, Siemens Healthcare Ltd, Beijing, China, ⁵MR Application, Siemens Healthcare Ltd, Jinan, China

The aim of this study was to evaluate the diagnostic performance of three advanced diffusion techniques (IVIM, DKI and DWI) which based on ZOOMit in demonstrating lesions in thyroid and parathyroid area. Results showed that D* in IVIM, MK in DKI and ADC in DWI were superior than other diffusion parameters (D, F in IVIM, MD in DKI) in accurately locating lesions as well as differentiating between lesions and normal thyroid parenchyma.

Zhang Jiulong¹, Shi Nannan¹, Zhang Yijun¹, Ye Wen¹, Zhang yong², Shan fei¹, and Shi Yuxin^1
1radiology department, Shanghai public health clinical center, shanghai, China, ²General surgery, Shanghai public health clinical center, shanghai, China

This study used ivim-dwi combined with sDKI models to quantitatively evaluate the differential diagnosis and histological grading prediction of retroperitoneal liposarcoma subtypes. Our results indicated that IVIM-DWI combined with sDKI models could accurately differentiate partial subtypes of RPLS, which was helpful for clinical selection of the optimal treatment strategy.

Shao-Chieh Lin¹, Jui-Heng Lin¹, Chun-Jung Juan^2,3,4, Kai-Min Chien⁵, Teng-Yi Huang⁶, Yi-Jui Liu⁷, Chang Hsien Liu ⁵, Ya-Hui Li⁵, Szu Hsien Chou ⁵, and Chi-Feng Hsieh^5
1Master 's Program of Biomedical Informatics and Biomedical Engineering, Feng Chia University, Taichung, Taiwan, ²Department of Medical Imaging, China Medical University Hsinchu Hospital, Hsinchu, Taiwan, ³Department of Radiology, School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan, ⁴Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan, ⁵Department of Medical Imaging, Chinese Medical University Hsinchu Hospital, Hsinchu, Taiwan, ⁶Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ⁷Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan

The study is to quantitatively compare the diagnostic ability of ADC in distinguishing three types of parotid tumor between the ADC measurement on slice with the largest tumor and whole tumor. This retrospective study enrolled 13 patient for each PMAs, WTs and MTs. All participants underwent 1.5-T fat-saturated EP-DWI. Our results show that ADC and AUC on largest slice and whole tumor were similar in three tumors. ADC of the slice with the largest tumor, which tumor size over 1/3 whole tumor volume, could instead the ADC of whole tumor to diagnosis the PMA, WT and MT in parotid gland.

Qing Xu¹, Weiqiang Dou², and Jing Ye^1
1Department of Radiology, Clinical Medical School of Yangzhou University, Northern Jiangsu People’s Hospital, Yangzhou, 457, China, ²GE Healthcare, MR Research China, Beijing, China

In this study, we aimed to investigate whether intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) techniques can be used to evaluate the pathological grade of clear cell renal cell carcinoma (ccRCC) patients preoperatively. As a result, the IVIM-related parameters (ADC, apparent diffusion coefficient; D, true diffusivity) and DKI-related parameters (MD, mean diffusivity; MK, mean kurtosis) have shown significant differences between low- and high-grade ccRCC(0.58±0.11 vs 0.48±0.08, 1.39±1.18 vs 0.98±0.21, 2.12±0.35 vs 1.59±0.32, 0.53±0.13 vs 1.59±0.32; p<0.05). Therefore, IVIM and DKI techniques can be used effective tools to differentiate low- and high-grade ccRCC. 

Kurt G Schilling¹, Kristin P O'Grady^1,2, Samantha By³, Haley Feiler¹, Francesca Bagnato⁴, Bennett A Landman^1,5,6,7, and Seth A Smith^1,5,8
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University Medial Center, Nashvillet, TN, United States, ³Hyperfine Research Inc, Guilford, CT, United States, ⁴Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, ⁵Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ⁶Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ⁷Electrical Engineering, Vanderbilt University, Nashville, TN, United States, ⁸Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States

We investigate multi-compartment diffusion MRI models in the in vivo spinal cord of multiple sclerosis (MS) patients. We find significant differences in diffusion measures of tissue microstructure and diffusivity indices between healthy controls (N=21) and MS patients (N=12). We also explore their relationships to clinical data, including disability scores, 25-foot walk tests, and disease duration, and note unique trends in these measures with increasing disability. These models may enable improved in vivo characterization of the spinal cord in MS patients and enable quantification of changes in meaningful tissue microstructure indices.

Eo-Jin Hwang ¹ and Moon Hyung Choi^2
1Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea, ²Eunpyeong St.Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea

Prostate Imaging-Reporting and Data System (PI-RADS) suggests acquiring multiple apparent diffusion coefficient (ADC) maps including the lowest b-values between 50-100s/mm² and highest b-values greater than 1400s/mm². Radiomics is a novel field in medical imaging to advance decision support by utilizing large amount of quantitative features. In this study, we employed radiomics from ADC maps and a linear regression model to differentiate prostate cancer from benign tissues and evaluated the effect of various b-value combinations on ADC maps. We discovered that ADC with the b-values of 100 and 1000s/mm² was most effective in discriminating prostate cancer with high accuracy.

Xin Li¹, Ryan Kopp^2,3, William D Rooney¹, Fergus Coakley⁴, and Mark Garzotto^2,3
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, ²Portland VA Medical Center, Portland, OR, United States, ³Urology, Oregon Health & Science University, Portland, OR, United States, ⁴Diagnostic Radiology, Oregon Health & Science University, Portland, OR, United States

The goal of this study is to investigate a new two-step approach in intra-voxel incoherent motion (IVIM) imaging data quantification. This methods first determines the slow diffusion constant (D) then the pseudo-perfusion parameters (D*, f) using the IVIM model fitting but holding D at pre-determined value.  Results show that the new approach returns more consistency parametric maps and the new modeling is favored by Akaike information criterion (AIC).

Gregory Lemberskiy^1,2, Yousef Mazaheri³, Herbert Alberto Vargas³, Ricardo Otazo³, Els Fieremans¹, and Dmitry S Novikov^1
1Radiology, New York University School of Medicine, New York, NY, United States, ²Microstructure Imaging INC, New York, NY, United States, ³Memorial Sloan Kettering Cancer Center, New York, NY, United States

For prostate cancer imaging, increasing the echo time selectively suppresses the cellular tissue, and emphasizes luminal water. We study the ADC dependence on echo time and diffusion time in 3 patients with PIRADS≥4 lesions, and propose a modeling strategy to interpret the changes in signal, as lumen diameter and volume fraction shrink during cancer progression. We evaluate cellular and luminal diffusivities, volume fractions, and luminal diameters as cancer biomarkers.

Mei Xue¹, Lizhi Xie², and Jing Li^3
1Radiology, Cancer Hospital Chinese Academy of Medical Sciences, Beijing, China, ²GE Healthcare, MR Research China, Beijing, Beijing, China, ³Cancer Hospital Chinese Academy of Medical Sciences, Beijing, China

Accurate identification of axillary lymph node(ALN) involvement in patients with breast cancer is crucial for prognosis and treatment strategy decisions. We developed a clinical model based on breast MR imaging and clinicopathologic characteristics to predict ALN metastasis. Our findings suggest that the clinicopathological features of breast tumor are highly correlated with axillary lymph node metastasis. It can be used to assist clinicians to predict LN metastasis non-invasively.

Isaac Vicente Manzanera Esteve¹, Angel F Farinas¹, Alonda C Pollins¹, Wesley P Thayer¹, Mark Does¹, and Richard Dortch^1
1VUIIS, Vanderbilt University Medical Center, Nashville, TN, United States

High-resolution DTI of ex vivo rat sciatic nerve yields viable biomarkers of peripheral nerve recovery following partial transection and surgical repair. FA values decreased with increasing cut depth at 4 weeks. By week 12, the three partial cuts showed elongated FA distributions, most likely representing regions with regenerated (high FA values) and degenerated axons (low FA values). FA finding are influenced by pathological features that affect diffusion both perpendicular and parallel to the axons.  

Dimitra Flouri^1,2, Jack RT Darby³, Stacey L Holman³, Sunthara R Perumal⁴, Anna L David^5,6, Andrew Melbourne^1,2, and Janna L Morrison^3
1School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom, ²Department of Medical Physics & Biomedical Engineering, University College London, London, United Kingdom, ³Early Origins of Adult Health Research Group, University of South Australia, Adelaide, Australia, ⁴Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, Australia, ⁵Institute for Women's Health, University College London, London, United Kingdom, ⁶NIHR University College London Hospitals Biomedical Research Center, London, United Kingdom

Abnormal development of the placenta is postulated as the root cause of preeclampsia and fetal growth restriction. Diffusion-Weighted imaging techniques are considered to give additional placental information. Animal models have been important in invasive validation studies for MRI measurements, as they allow for controlled experiments and analysis of multiple time-points during pregnancy. This study characterises diffusion and perfusion properties of the placenta such as the apparent diffusion coefficient, T2 measurements, fractional anisotropy and perfusion fraction derived from intravoxel incoherent motion  analysis on sheep placental tissue in order to validate new imaging markers of placental function.

Junting Zou¹, Jilei Zhang², Yuanyuan Xie³, yunpeng Shen⁴, Jiacheng Du⁴, Yang Chen⁴, Yang Chen⁴, Bing Zhang³, and Xiaoli Mai^5
1Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China, ²Clinical Science, Philips Healthcare, Shanghai, China, ³Nanjing Drum Tower Hospital, Nanjing, China, ⁴Southeast University, Nanjing, China, ⁵Radiology, Nanjing Drum Tower Hospital, Nanjing, China

The labelled SPIO of the transplanted MSCs were found in spinal cord segment of TSCI based on T1w and T2w images. The DTI can be of great value in the dynamic evaluation of morphological and neurological changes in beagles after TSCI. FA values are correlated with the impairment and repair of the fiber tracts of the spinal cord. The FA value can satisfactorily evaluate the completeness of the fiber tracts after SCI and the repair of them by stem cells. The combination of conventional MRI and DTI is of great clinical importance for the diagnosis and therapeutic evaluation of SCI.

Xianfu Luo¹, Jing Ye¹, Weiqiang Dou², Jun Sun¹, and Wei Xia^1
1Radiology, Clinical Medical School of Yangzhou University, Northern Jiangsu People’s Hospital, Yangzhou, China, ²GE Healthcare，MR Research China, Beijing, China

We aimed to compare mono-exponential bi-exponential and stretched-exponential diffusion-weighted imaging(DWI) model in characterizing nonalcoholic liver disease (NAFLD) by providing multiple quantitative parameters. The diagnosis performance for early detection nonalcoholic steatohepatitis (NASH) was compared using characteristic operating curve analysis. Stretched-exponential DWI performed as well as bi-exponential DWI and better than mono-exponential DWI in the noninvasive characterization of NAFLD severity.