Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy


NEURO 1 (13:30-15:30)

1699-1709 Head & Neck Imaging
1710-1732 Spinal Cord 
1733-1749 Normal Developing Brain
1750-1772 Fetal & Pediatric Neuroimaging
1773-1805 Normal Brain Anatomy
1806-1838 Normal Brain Physiology
1839-1842 Normal Ageing Brain
1843-1861 Brain Cancer
1862-1872 Animal Models Stroke & Blood Brain Barrier

Head & Neck Imaging

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1699.   Multiparametric Analysis using pCASL, IVIM and DKI for Head and Neck Squamous Cell Carcinoma
Noriyuki Fujima1, Daisuke Yoshida1, Tomohiro Sakashita1, Akihiro Homma1, Yuriko Suzuki2, and Kohsuke Kudo1
1Hokkaido University Hospital, Sapporo, Hokkaido, Japan, 2Philips Electronics Japan, Tokyo, Japan

Tumor diffusion and perfusion is important factor for the assessment of head and neck squamous cell carcinoma (HNSCC). The aim of this study was to evaluate diagnostic value of the pCASL, IVIM and DKI as multi-parametric analysis in non-surgically treated HNSCC by assessing its usefulness as predictor of local control of primary tumor. This study revealed that noninvasive multiparametric evaluation by combining pCASL, IVIM, and DKI can provide high diagnostic accuracy to determine whether successful local control of primary tumor was obtained or not in HNSCC.

1700.   Assessment of Tumor Blood Flow and its Correlation with Histopathologic Features in Warthin tumors and Pleomorphic adenomas of the Salivary Gland using Pulsed-Continuous Arterial Spin Labeling Images
Tatsuya Yamamoto1, Nobuyuki Kosaka1, Masaki Mori2, Yoshiaki Imamura2, and Hirohiko Kimura1
1Department of Radiology, University of Fukui, Fukui, Japan, 2Division of Surgical Pathology, University of Fukui, Fukui, Japan

No reports have focused on the evaluation of tumor blood flow (TBF) using pseudo-continuous arterial spin labeling (pcASL) in the salivary gland tumor. However, we demonstrated a significant difference in TBF between a salivary gland Warthin tumor and pleomorphic adenoma. The significant correlation between TBF and the tumor vascular density (p < 0.01, rs = 0.93) suggests that precise evaluation of the tumor perfusion state could be accomplished using pcASL. Thus, differential diagnosis of a salivary gland tumor may be possible to some extent even without the use of contrast material.

1701.   Ultra High Resolution Imaging of Rodent Cochlea using a Composite Gradient System on a 3T Clinical MRI
Seong-Eun Kim1, K Craig Goodrich1, Joshua D Kaggie1, Richard Wiggins1, Travis Abele1, J Rock Hadley1, Bradley D Bolster, Jr2, and Dennis L Parker1
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, 2Siemens Healthcare, Salt Lake City, Utah, United States

Ultra high resolution MRI capable of resolving the cochlear internal structures has been performed in small bore MRI scanners with higher field strength(>4.7T) and gradient performance. We hypothesize that improved images of the cochlear anatomy may also be obtained on high field human MRI scanners that have increased gradient performance and performed high resolution rodent cochlea imaging using an insert gradient array simultaneously with the whole body gradients of our 3T clinical MRI scanner. The use of composite gradients will allow for higher spatial resolution cochlear imaging while maintaining acceptable SNR and scan duration and decreasing artifact.

1702.   An exploratory pilot study into the correlation of MRI perfusion, diffusion parameters and 18F-FDG PET metabolic parameters in primary head and neck cancer
Jin Wook Choi1, Miran Han1, Soo Jin Lee2, Nae Jung Lim1, and Sun Yong Kim1
1Radiology, Ajou University School of Medicine, Suwon, Gyunggido, Korea, 2Nuclear Medicine, Ajou University School of Medicine, Suwon, Gyunggido, Korea

Microcirculation, cellularity and glucose metabolism may have relationship or affect each other in the same tumor. The understanding of their relationship could contribute to the field of oncologic imaging such as tumor characterization, guidance for treatment planning, early prediction of treatment responses and evaluation of treatment outcome. In this study, we investigated the relationships between tumor metabolism determined by 18FDG positron emission tomography, tumor microcirculation determined by dynamic contrast enhanced MRI, and tumor cellularity determined by diffusion MRI in patients with primary head and neck cancer.

1703.   Diffusion-weighted MRI as a biomarker in uncompensated vestibular patients - preliminary results.
Angelique Van Ombergen1, Ben Jeurissen2, Floris Vanhevel3, Wim Van Hecke4, Vincent Van Rompaey5, Jan Sijbers2, Stefan Sunaert6, Paul Parizel3, Paul van de Heyning5, and Floris Wuyts1
1Antwerp University Research center for Equilibrium and Aerospace, University of Antwerp, Antwerp, Belgium, 2Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium, 3Department of Radiology, Antwerp University Hospital & University of Antwerp, Antwerp, Belgium, 4Icometrix, Leuven, Belgium, 5Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital & University of Antwerp, Belgium, 6Department of Radiology, University Hospital of the Catholic University of Leuven, Leuven, Belgium

Diffusion parameters in uncompensated vestibular patients and healthy controls subjects were investigated. In all subjects multi-shell high angular resolution diffusion weighted (DW) data were acquired and we performed tractography. Significant differences in fractional anisotropy (FA) values were found at the right parietal operculum 2 and cerebellar peduncles. Reduced FA in these regions may explain the symptoms of continuous vertigo and inadequate compensation due to vestibular lesions. This pilot study suggests that diffusion parameters may serve as biomarkers for vestibular induced neuroplasticity and unravel the relationship between brain connectivity and vestibular complaints.

1704.   High Resolution MRI of the Sellar Structures via Transsphenoidal Placement of a Dedicated Interventional Pituitary Coil: Development and Cadaveric Testing.
Prashant Chittiboina1, Lalith Talagala2, Hellmut Merkle3, Joelle E Sarrls4, Blake K Montgomery1, Russell R Lonser5, Edward H Oldfield6, Alan P Koretsky3, and John A Butman7
1Surgical Neurology Branch/ NINDS, National Institutes of Health, Bethesda, Maryland, United States, 2NIH MRI Research FAcility/ NINDS, National Institutes of Health, Bethesda, Maryland, United States, 3Laboratory of Functional & Molecular Imaging/ NINDS, National Institutes of Health, Bethesda, Maryland, United States, 4NIH MRI Research Facility/ NINDS, National Institutes of Health, Bethesda, Maryland, United States, 5Department of Neurological Surgery, The Ohio State University, Columbus, Ohio, United States, 6Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, United States, 7Radiology and Imaging Sciences/ Clinical Center, National Institutes of Health, Bethesda, Maryland, United States

MRI detects pituitary microadneomas in 50% of cases. Transsphenoidal surgery allows placement of an MRI receiver coil within the sphenoid, dramatically improving SNR. A 12 mm diameter 1.5 T interventional pituitary surface coil (IPSC) was prototyped. The IPSC was positioned using the transsphenoidal approach in two cadaveric heads. The SNR gain with the IPSC was 5-10 fold compared to the 8-channel head coil. Structures visible using IPSC included the pituitary capsule, intercavernous sinus, and medial wall of the cavernous sinus. This novel coil may become an important intraoperative tool for transsphenoidal surgery.

1705.   Semi-Automated DTI Measurement of the Brachial Plexus using Tracts of Interest
Jos Oudeman1, Martijn Froeling1,2, Gustav J Strijkers3, Mario Maas1, Dennis F R Heijtel1, Bram F Coolen1, Camiel Verhamme4, Matthan W A Caan1, Marianne de Visser4, and Aart J Nederveen1
1Radiology, Academic Medical Center, Amsterdam, Noord Holland, Netherlands, 2Radiology, University Medical Center, Utrecht, Utrecht, Netherlands, 3Biomedical NMR, Department of biomedical engineering, Eindhoven University of Technology, Eindhoven, Brabant, Netherlands, 4Neurology, Academic Medical Center, Noord Holland, Netherlands

It has been suggested that DTI derived parameters may sensitive for detecting immune mediated disease activity in the brachial plexus, and thus may be an interesting new diagnostic tool.

1706.   Real-time MRI of Oropharyngeal Swallowing Function: Initial Clinical Results
Shuo Zhang1, Arno Olthoff2, Per-Ole Carstens3, and Jens Frahm1
1Biomedizinische NMR Forschungs GmbH, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Lower Saxony, Germany, 2Department of Otorhinolaryngology, University Medical Center, Goettingen, Lower Saxony, Germany, 3Department of Neurology, University Medical Center, Goettingen, Lower Saxony, Germany

Previous studies of swallowing function using conventional clinical methods suffer mainly from invasiveness and limited visualization planes. Here, we applied the recently introduced real-time MRI technique based on undersampled radial FLASH and nonlinear inversion, which provided consecutive T1-images of swallowing actions with an in-plane resolution of 1.5 mm and acquisition times of 41 ms (24 fps) almost free from artifacts. Up to 12 distinct swallowing events with a well-orchestrated temporal pattern could be characterized. Preliminary clinical results with timing quantification showed significant difference between healthy subjects and patients with inclusion body myositis, which promises a useful tool for disease diagnosis.

1707.   The Clinical Impact of MRI for Assessment of Squamous Cell Carcinoma of the Tongue
Kotaro Sekiya1,2, Hirofumi Kuno1, Satoshi Fujii3, Masaaki Suemitsu1,4, Takashi Kaneda2, and Mitsuo Satake1
1Diagnostic Radiology Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan, 2Department of Radiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan, 3Pathology Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan, 4Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan

Purpose: To investigate the relationship between the features of extrinsic muscle/ neurovascular bundle invasion demonstrated by 3T-MR modalities and treatment outcome in patients with tongue cancer. Methods: 3T-MRI studies of 168 subjects with tongue cancer were retrospectively reviewed with particular attention for extrinsic muscle / neurovascular bundle invasion. Results: Extrinsic muscle invasion (P = 0.001) and neurovascular bundle invasion (P = 0.003) were significant predictors for cervical lymph node metastases. Conclusion: MRI may contribute to prediction of cervical lymph node metastases with tongue cancer.

1708.   3D arterial spin label perfusion MR imaging of head and neck tumors: the initial results
Yu Chen1, Zhuhua Zhang1, Zhengyu Jin1, and Kaining Shi2
1Radiology Department, Peking Union Medical College Hospital, Beijing, Beijing, China, 2Global MR Applications and Workflow (China),GE Healthcare, Beijing, China

This prospective study is aimed to evaluate the feasibility of 3D arterial spin label perfusion MRI technique applied to the head and neck tumors. 17 enrolled patients underwent 3D ASL MR examinations with three different PLD (1025ms, 1525ms, and 2525ms). SNRs and blood flow (BF) values of tumors or lymph nodes were analysis. The mean SNR of ASL with 1025ms was significantly higher than the other two ASL sequences (P<0.05). Mean BF values of the three ASL were not shown significant difference (P=0.514). Tumors with different histopathologic types had different BF values.

1709.   High resolution three dimensional morphometry and nasal air flow of the mammalian nose from multi-modal imaging
Thomas Neuberger1,2, Joseph P Richter3, Christopher R Rumple3, Andrew P Quigley3, Allison N Ranslow3, Timothy M Ryan4, Timothy D Stecko4, Benison Pang5, Blaire Van Valkenburgh5, and Brent A Craven3
1Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States, 2Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, United States, 3Applied Research Laboratory, Pennsylvania State University, University Park, PA, United States, 4Center for Quantitative X-Ray Imaging, Pennsylvania State University, University Park, PA, United States, 5Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States

This paper presents the current state-of-the-art techniques for reconstructing nasal form and function. The mammalian nasal cavity is a multi-purpose organ that houses a complex arrangement of bony turbinals and a tortuous, interconnected airway in which respiratory air conditioning, filtering of environmental contaminants, and chemical sensing occur. This study combines MRI and CT to build high resolution three dimensional models of the nasal cavity of six different mammals. The reconstructed models were used in computational fluid dynamics (CFD) simulations of nasal airflow. Future CFD simulations may include respiratory heat and moisture exchange and odorant mass transport.


Spinal Cord

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

Validation of a 2D Spinal Cord probabilistic atlas. Application to FA measurement and VBM study of the GM atrophy occurring with age
Manuel Taso1,2, Arnaud Le Troter1,2, Michaël Sdika3, Vladimir S. Fonov4, Julien Cohen-Adad5, Maxime Guye1,2, Jean-Philippe Ranjeva1,2, and Virginie Callot1,2
1CRMBM UMR 7339, Aix-Marseille Université, CNRS, Marseille, France, 2Hopital de la Timone, pôle d'Imagerie Médicale, CEMEREM, AP-HM, Marseille, France, 3CREATIS UMR 5220 U1044, Université de Lyon, CNRS, INSERM, Lyon, France, 4Montreal Neurological Institute, McGill University, Montreal, QC, Canada, 5Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada

A 2D spinal cord probabilistic atlas has been recently proposed. The aim of the current work was to strengthen its construction by increasing the number of subjects involved, to validate its use for an automated white and gray matter segmentation. Investigations for automated regional FA analysis and for group studies (VBM analysis of GM distribution) were then conducted. The WM/GM atlas-based segmentation showed great potential (DICE>0.75), and further refinements that have to be brought for DTI quantification have been identified. Finally, the use of the probabilistic atlas for group studies allowed highlighting evidence of anterior GM atrophy occurring with age.

1711.   Diffusion-Weighted Imaging of the Spine Using Readout-Segmented EPI and Local B0 Shimming
David Andrew Porter1, Stephan Biber1, Nina Kaarmann1, and Katrin Wohlfarth1
1Healthcare Sector, Siemens AG, Erlangen, Germany

Diffusion-weighted (DW), readout-segmented EPI (rs-EPI) substantially reduces the susceptibility artifact seen with single-shot EPI. Previous studies have demonstrated how this improved image quality is beneficial for clinical, diffusion-weighted examinations of the spinal cord. However, this application is often limited by poor performance of chemical-shift-selective fat saturation at the base of the cervical spine due to the poor B0 field uniformity in this region. This study demonstrates how this problem can be overcome by using a prototype head-and-neck coil with integrated local B0 shim coils, making it possible to acquire robustly high-quality DW images with whole-spine coverage.

1712.   Detection of GABA, Aspartate and Glutathione in the Human Spinal Cord
Andreas Hock1,2, Bertram Wilm1, Giorgia Zandomeneghi3, Garyfalia Ampanozi4, Sabine Franckenberg4, Nicola De Zanche5, Jurek Nordmeyer-Maßner1, Spyros S. Kollias6, Thomas Kraemer4, Michael Thali4, Matthias Ernst3, and Anke Henning1,7
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Zurich, Switzerland, 2Department of Psychiatry, Psychotherapy and Psychosomatics Hospital of Psychiatry, University of Zurich, Zurich, Zurich, Switzerland, 3Physical Chemistry, ETH Zurich, Zurich, Zurich, Switzerland, 4Institute of Forensic Medicine, University of Zurich, Zurich, Zurich, Switzerland, 5Department of Medical Physics, Cross Cancer Institute and University of Alberta, Edmonton, Alberta, Canada, 6Institute of Neuroradiology, University Hospital of Zurich, Zurich, Zurich, Switzerland, 7Institute for Biological Cybernetics, Max Planck Institute, Tuebingen, Baden Württemberg, Germany

The aim of this investigation was to expand the number of predictive markers of in vivo MR spectroscopy measurements of the human spinal cord. Therefore, data was acquired in healthy volunteers with sophisticated motion and instability correction methods as well as advanced hardware enabling the acquisition with excellent spectral quality. Aspartate, Glutathione, and GABA could be additionally identified. In addition, for the first time, the findings were cross-validated with those retrieved from a cadaveric spinal cord sample using high resolution, magic angle spinning NMR measurements enabling a qualitative indication of the presence of the additional metabolite markers found in vivo.

1713.   MNI-Poly-AMU average anatomical template for automatic spinal cord measurements
Vladimir S. Fonov1, Arnaud Le Troter2,3, Manuel Taso3,4, Geoffrey Leveque5, Marc Benhamou5, Michaël Sdika6, D. Louis Collins1, Virginie Callot2,7, and Julien Cohen-Adad5
1Montreal Neurological Institute, McGill University, Montreal, QC, Canada, 2CNRS, Aix-Marseille Université, Marseille, France, 3Pôle d’imagerie, Hôpital de la Timone, Marseille, France, 4CNRS, Aix-Marseille Universite, Marseille, France, 5Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada,6CREATIS, Universite de Lyon, INSA-Lyon, France, 7Pôle d’imagerie, APHM, Hôpital de la Timone, Marseille, France

We present an unbiased anatomical template of the human spinal cord built from T2-weighted MRI scans of 17 subjects and T2*-weighted based semi-automatic segmentations of the spinal cord into gray matter, white matter and CSF from another 15 subjects. The proposed template is used in a semi-automatic image processing pipeline for measurements of spinal cord atrophy.

1714.   B0 Fluctuations Within the Human Spinal Cord During Respiration at 7.0 Tesla
David R Pennell1, Anuj Sharma2, Henry H. Ong1,3, and Seth A Smith1,3
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 3Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States

This experiment quantitatively evaluates B0 fluctuations within the human cervical spinal cord at 7.0 Tesla due to bulk susceptibility changes during respiration.

1715.   Resting state functional connectivity in the human cervical spinal cord at 7 Tesla: preliminary results across healthy controls
Robert L Barry1,2, Seth A Smith1,2, Adrienne N Dula1,2, and John C Gore1,2
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States

Blood oxygenation level dependent signal fluctuations in the resting brain have been exploited to characterize low-frequency functional connectivity within specific neural circuits. However, there have been no previous rigorous reports of resting state correlations in the spinal cord. In a cohort of healthy controls we observed robust functional connectivity between left and right ventrolateral (motor) horns, and left and right dorsal (sensory) horns. No statistically significant correlations are observed between spinal gray and white matter, suggesting that observed correlations between gray matter horns cannot be simply attributed to spatially correlated physiological noise and likely represent genuine connectivity.

1716.   Single–shell diffusion MRI NODDI with in vivo cervical cord data
Francesco Grussu1, Torben Schneider1, Hui Zhang2, Daniel C. Alexander2, and Claudia A. M. Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, England, United Kingdom, 2Department of Computer Science and Centre for Medical Image Computing, University College London, London, England, United Kingdom

Neurite Orientation Dispersion and Density Imaging (NODDI) is a novel diffusion MRI technique which relies on double–shell acquisition. To date, it is not clear whether a reduced NODDI model could be fitted to single–shell diffusion data of areas such as the spinal cord. In this work, we compare single–shell estimates of NODDI parameters to double–shell ground truth in the healthy cervical cord in vivo, and our results would be informative for retrospective NODDI analysis of in vivo single–shell diffusion data of the same area.

1717.   Spinal Cord Imaging with Demodulated bSSFP
Michael N Hoff1, Qing-San Xiang2,3, and Jalal B Andre1
1Department of Radiology, University of Washington, Seattle, WA, United States, 2Department of Radiology, University of British Columbia, Vancouver, BC, Canada,3Department of Physics, University of British Columbia, Vancouver, BC, Canada

Demodulated balanced steady state free precession (bSSFP) is employed to image the spinal cord at 3T. Four phase cycled images are acquired from a cervical spine patient, and a complex plane geometric solution is exploited for elimination of dark bands and general signal modulation. A complex average of the acquired data shows reduced bands but uneven signal intensity in the CSF, whereas the proposed solution yields homogeneous CSF signal without banding such that the spinal cord and epidural space are easier to visualize.

1718.   Quantitative 3D evaluation of white matter degeneration in rat spinal cord following Dorsal Column transection using frequency shift mapping
I-Wen Evan Chen1, Vanessa Wiggermann1, Jie Liu2, Wolfram Tetzlaff2,3, Piotr Kozlowski1,4, and Alexander Rauscher1,4
1MRI Research Center, Vancouver, B.C., Canada, 2International Collaboration On Repair Discoveries, Vancouver, B.C., Canada, 3Zoology, University of British Columbia, Vancouver, B.C., Canada, 4Radiology, University of British Columbia, Vancouver, B.C., Canada

Recent studies of contrast in white and gray matter (WM/GM) of the central nervous system (CNS) have provided evidence for theories predicting phase (and frequency shift) dependence on tissue architecture, in the cellular and subcellular components of tissue [2-4]. Combining the well-defined (anisotropic) architecture of the rat spinal cord dorsal column (DC) transection model of axotomy, we study areas of neuronal damage consistent with (expected pathology) of Wallerian and retrograde degeneration. 3D frequency shift mapping of spinal cords bi-directional to the injury were generated from 3D multi-gradient echo (MGE) phase, and used to investigate progressive degeneration over several weeks

1719.   Resolving the anatomic variability of the human cervical spinal cord: a solution to facilitate advanced neural imaging.
David W. Cadotte1,2, Adam Cadotte3, Julien Cohen-Adad4, David Fleet5, Micha Livne5, David Mikulis6, and Michael G. Fehlings1,7
1Neurosurgery, University of Toronto, Toronto, Ontario, Canada, 2University Health Network, Toronto Western Reserach Institute, Toronto, ON, Canada, 3CREMS program, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada, 4Institute of Biomedical Engineering, Ecole Polytechnique de Montréal, Quebec, Canada,5Department of Computer Science, University of Toronto, ON, Canada, 6Department of Medical Imaging, Division of Neuroradiology, University of Toronto, ON, Canada,7University Health Network, Toronto Western Reserach Institute, ON, Canada

In this work we provide a novel, quantitative solution to deal with the anatomical variability of the human cervical cord. To do this, we identify the longitudinal axis of the brainstem-spinal cord with a polynomial spline function. Based on user-defined markings of segmental nerve rootlets as ground truth data, we identify the position of spinal segments relative to the ponto-medullary junction (PMJ). For the first time, we report a population distribution of the segmental anatomy of the cervical spine that has direct implications for the interpretation of advanced imaging studies most often conducted across groups of subjects.

1720.   Neurite Orientation Dispersion and Density Imaging of the cervical cord in vivo
Francesco Grussu1, Torben Schneider1, Hui Zhang2, Daniel C. Alexander2, and Claudia A. M. Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, England, United Kingdom, 2Department of Computer Science and Centre for Medical Image Computing, University College London, London, England, United Kingdom

Neurite Orientation Dispersion and Density Imaging (NODDI) is a novel diffusion MRI technique providing indices which are appealing biomarkers in diseases of brain and spinal cord. Here, we demonstrate for the first time the application of the full NODDI technique to the healthy cervical cord in vivo, assessing the reproducibility of its metrics and their relationship with Diffusion Tensor Imaging (DTI) indices. The analysis confirmed findings in the brain and demonstrated that NODDI can be a feasible and more specific alternative to DTI for in vivo spinal cord diffusion MRI.

1721.   Gross structure of magnetic field inhomogeneity in the human cervical spinal cord
Paul Summers1, Armando Bauleo2, Stefania Favilla2, Fabiola Cretti2,3, Fausta Lui2, and Carlo A Porro2
1UniMoRE / IEO / Policlinico Milan, Modena, MO, Italy, 2University of Modena and Reggio Emilia, Modena, Italy, 3Ospedali Riuniti di Bergamo, Bergamo, Italy

We have measured the magnetic field (B0) in the human cervical spinal cord. We observed a large-scale B0 variation of 150-300Hz difference between the brain and mid-cervical spine, with a partial recovery in the lower spinal cord. Superposed on this large-scale feature were smaller oscillations in B0 having spatial intervals consistent with the lengths of the corresponding vertebral bodies. In contrast to prior studies, we found minimal difference in the temporal variation in B0 along the length of the cervical spine. The observed inhomogeneity profile provides a context for understanding the difficulties of shimming in the cervical spine.

1722.   White Matter and Grey Matter Magnetisation Transfer Measurements in the Lumbo-Sacral Enlargement: A Pilot Study With the Use of Radial Acquisition Profile at 3T
Marios C. Yiannakas1, Rebecca S. Samson1, Chinyere O. Ugorji1, David H. Miller1, and Claudia A. M. Wheeler-Kingshott1
1Neuroinflammation, UCL - Institute of Neurology, London, London, United Kingdom

In this work the possibility of obtaining magnetisation transfer ratio (MTR) measurements in grey matter (GM) and white matter (WM) within the lumbo-sacral enlargement (LSE) is investigated. This is achieved with the use of radial acquisition profile to alleviate the effects of physiological motion associated with this level of the spinal cord. The method presented maybe used with a commercially available MRI system and future studies will be directed at assessing the value of this method to study neurological disease affecting the lumbar spinal cord.

1723.   ZOOM and non-ZOOM Spinal Cord Diffusion Tensor Imaging protocols for multi-centre studies
Rebecca Sara Samson1, Julien Cohen-Adad2, Torben Schneider1, Alex Kenneth Smith3, Seth A Smith4, and Claudia A M Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom, 2Institute of Biomedical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada, 3Department of Radiology & Radiological Sciences, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, Tennessee, United States, 4Department of Biomedical Engineering, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, Tennessee, United States

Diffusion Tensor Imaging parameters have been shown to be sensitive to changes in the diseased spinal cord (SC). However, imaging the cord can be challenging due to patient-related and physiological motion. Rapid acquisition sequences such as Echo Planar Imaging (EPI) are desirable but may suffer from image distortions. Here we present a multi-centre comparison of two acquisition protocols, one using ZOOM-EPI, and one only using options available on standard clinical scanners such as outer volume suppression (OVS).

1724.   Phase sensitive inversion recovery imaging of the spinal cord in clinical scan times
Nico Papinutto1, Valentina Panara1,2, Sinyeob Ahn3, Kevin Johnson3, Regina Schlaeger1,4, Eduardo Caverzasi1, William Stern1, Bruce Cree1, Stephen Hauser1, and Roland G Henry1
1Dept. of Neurology, UCSF, San Francisco, CA, United States, 2ITAB - Institute of Advanced Biomedical Technologies, University "G. D'Annunzio", Chieti, Italy, 3Siemens Healthcare USA, San Francisco, CA, United States, 4Dept. of Neurology, University Hospital Basel, University of Basel, Basel, Switzerland

In this study we present two spinal cord Phase Sensitive Inversion Recovery (PSIR) imaging protocols that candidate to be implemented in clinical Multiple Sclerosis centers. We optimized a 2D and a 3D version of the same protocol that show great canal/cord, grey matter/white matter and lesion/cord contrasts, retaining a good in plane resolution and short acquisition time. First we show how these protocols provide consistent and reproducible cord and grey matter area measurement. Second we show how the 3D version of the protocol provides a very reliable detection and localization of MS lesions. The short scan time makes the two proposed protocols very interesting for clinical environments.

1725.   Preliminary Investigation of Ultrashort T2* in Healthy Cervical Cord Grey Matter and White Matter In Vivo at 3T
Marios C. Yiannakas1, Bhavana S. Solanky1, Frank Riemer1, Daniel J. Tozer1, Hugh Kearney1, David H. Miller1, and Claudia A. M. Wheeler-Kingshott1
1Neuroinflammation, UCL - Institute of Neurology, London, London, United Kingdom

In this work the feasibility of using ultrashort echo time (UTE) imaging to obtain T2* measurements in grey matter (GM) and white matter (WM) independently within the upper cervical cord in vivo is investigated. A linear fit of the natural logarithm in two echo times (2-point fit) is used for the measurements. The results show a distinct difference in T2* between GM and WM which is suggestive of differences in macromolecular structure. The method presented is clinically practical and maybe used in the future to study neurological disease affecting the spinal cord.

1726.   MRI Acquisition and Analysis Protocol for In Vivo Grey Matter and White Matter Cross-Sectional Area Measurements in the Lumbo-Sacral Enlargement at 3T
Marios C. Yiannakas1, Puneet Kakar1, Luke R. Hoy1, David H. Miller1, and Claudia A. M. Wheeler-Kingshott1
1Neuroinflammation, UCL - Institute of Neurology, London, London, United Kingdom

A new image acquisition and analysis protocol is presented allowing segmentation of grey matter (GM) and white matter (WM) within the lumbo-sacral enlargement (LSE) at 3T. The optimised image acquisition scheme in conjunction with a robust image analysis method represents a clinically-viable method for obtaining reproducible measurements of GM and WM cross-sectional areas (CSA) within the LSE. In this work, normative tissue-specific CSA data are presented, hitherto unreported; future studies will investigate the value of the method presented here for assessing neurological diseases.

1727.   Multisite DTI of the spinal cord with integrated template and white matter atlas processing pipeline
Julien Cohen-Adad1,2, Rebecca S Samson3, Torben Schneider3, Alex K Smith4, Marc Benhamou1, Geoffrey Leveque1, Seth A Smith5, and Claudia A M Wheeler-Kingshott3
1Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 2Functional Neuroimaging Unit, IUGM, Universite de Montreal, Montreal, QC, Canada,3NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, United Kingdom, 4Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology and Radiological Sciences, Vanderbilt University, Tennessee, United States, 5Department of Biomedical Engineering, Vanderbilt University, Tennessee, United States

We propose a framework for conducting DTI studies of the spinal cord across sites equipped with different MRI systems. The main features are: well-validated acquisition protocol including reduced field of view technique, registration to an existing spinal cord template using state-of-the-art methods and the use of a white matter atlas for quantifying DTI metrics in specific spinal tracts. The method is applicable to other acquisition techniques, such as magnetization transfer and functional MRI.

1728.   Manganese Enhanced MRI Assay of Spinal Cord Functional Connectivity
Xiaowei Zhang1, Naomi Santa Maria1, Samuel Barnes1, and Russell E. Jacobs1
1Biological Imaging Center, Caltech, Pasadena, California, United States

Synopsis: After Mn++ injection into spinal cord (SC), MR hyperintensity spreads along the the SC and can be followed by MR imaging over time. MEMRI of intact SC pathways offers an alternative method to evaluate axonal outgrowth and the functional connectivity in cellular graft therapies of injured or diseased spinal cord.

1729.   Image Registration Framework for Pixelwise Comparison of Ex Vivo MRI and Histology in Rat Model of Contusion Spinal Cord Injury
Andrew C.H. Yung1, Peggy Assinck2, Di Leo Wu3, Jie Liu2, Wolfram Tetzlaff2,4, and Piotr Kozlowski1,2
1UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada, 2ICORD, Vancouver, BC, Canada, 3Physics, University of British Columbia, Vancouver, BC, Canada, 4Zoology, University of British Columbia, Vancouver, BC, Canada

An image registration procedure was devised to compare ex vivo MRI (DTI) and histology for the contusion model of spinal cord injury in rats. The axonal stain sections that are encompassed by one MRI slice are registered to each other to form an "axon stain sum" image, which is then aligned to the DTI-derived trace weighted image by mutual-information affine registration. A target registration error of 0.150 mm was measured across 9 test animals (5 slices per cord). The resultant linear transformations can be used to perform pixelwise comparison between MRI and histology without warping the original data.

1730.   Correcting Myelin Water Fraction for T2 Changes Caused by Varying Phosphate Buffer Concentration in Aldehyde Fixed Spinal Cord Tissue
Henry Szu-Meng Chen1,2, Nathan Holmes3, Wolfram Tetzlaff3,4, and Piotr Kozlowski3,5
1UBC MRI Research Centre, Vancouver, British Columbia, Canada, 2Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 3ICORD, Vancouver, BC, Canada, 4Zoology, University of British Columbia, Vancouver, BC, Canada, 5Radiology, University of British Columbia, Vancouver, BC, Canada

This study looked at the impact of phosphate buffer (PB) concentration on MR measurements of myelin water fraction (MWF) in ex vivo rat spinal cord. The results show that T2 shortens as the concentration of PB decreases, which lead to a decrease in T2 of both the intra/extracellular and myelin water peak that inflate the measured MWF. The effect can corrected for by moving the upper bound of myelin water T2 range to the mean T2 of the two peaks as long as the myelin water T2 is long enough to be well characterized by the given echo time.

1731.   Sensitivity Assessment Comparison of Slice Accelerated Diffusion EPI vs. SSEPI for C-spine applications at 3T
Judy Rose James1, Peter D. Kollasch2,3, Blake A. Engberg1, Leland S. Hu1, Catherine Chong4, and Anshuman Panda1
1Radiology, Mayo Clinic, Scottsdale, AZ, United States, 2Mayo Clinic, AZ, United States, 3MR Research and Development, Siemens Medical Solutions USA, Inc, Rochester, MN, United States, 4Collaborative Research, Mayo Clinic, Phoenix, AZ, United States

Clinical DTI in the cervical spine (C-spine) employs the single shot EPI-based Diffusion Weighted Imaging (SS-EPI-DWI) technique. Given the propensity for image distortion and low signal to noise ratio, optimization of DTI image quality often requires an increase in the number of averages, at the cost of proportionally increasing scan time. A modified SS-EPI-DWI sequence called Slice-Accelerated-Single-Shot-Spin-Echo- EPI (commonly termed as Multiband-DWI) offers improved image quality while reducing scan time and image distortion. In this study, we will evaluate C-spine image acquisitions at 3T using Multiband-DWI and SS-EPI-DWI techniques, specifically comparing 1) qualitative image quality, 2) quantitative DWI/DTI metrics, and 3) acquisition scan time.

1732.   Phase Sensitive Inversion Recovery in Post Mortem Multiple Sclerosis Spinal Cord: Shades of Grey and White
Amy McDowell1, Marc Miquel2, Maria Papachatzaki1, Daniele Carassiti1, and Klaus Schmierer1
1Neuroscience and Trauma, Blizard Institute, London, Greater London, United Kingdom, 2Clinical Physics, Barts Health NHS Trust, London, Greater, United Kingdom

The usefulness of phase sensitive inversion recovery (PSIR) images in fixed post mortem multiple sclerosis (MS) spinal cord white matter (WM) and grey matter (GM) is examined. PSIR was optimised using T1 values acquired at 3T (inversion recovery method). The values obtained, and particularly the minor difference of T1 in WM and GM, suggest the assessment of the histological substrate of PSIR in post mortem spinal cord may not be feasible using fixed tissue. The use of unfixed samples should be explored, though access is limited


Normal Developing Brain

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1733.   What you see is not what you get: BOLD signal increases with age in children may be the result of increased neuronal-vascular coupling and not increased neuronal activity
Vincent Jerome Schmithorst1,2, Jennifer Vannest2, Gregory Lee2, Luis Hernandez-Garcia3, Elena Plante4, Akila Rajagopal2, and Scott Holland2
1Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, 2Radiology, Children's Hospital Medical Center, Cincinnati, OH, United States, 3Radiology, University of Michigan, Ann Arbor, MI, United States, 4Speech, Language, and Hearing Sciences, University of Arizona, AZ, United States

Neuronal-vascular coupling is a likely confound in developmental fMRI studies. We investigated the etiology of increasing BOLD signal with age during the developmental period (ages 3-18) using a simultaneous functional ASL-BOLD acquisition and a narrative comprehension task. Results show that while a region (left STG) of the brain exhibits increases in BOLD signal with age, these increases are the result of increased neuronal-vascular coupling and not increased neuronal activity. In fact, CMRO2 is actually found to decrease with age. This finding suggests results of increased BOLD signal or inter-regional correlations with age need to be interpreted with caution.

1734.   Exploring spatiotemporal dynamics of the cerebral blood flow of perinatal human brains with arterial spin labeling
Minhui Ouyang1, Peiying Liu1, Hanzhang Lu1, Lina Chalak2, Jonathan M Chia3, Andrea Wiethoff1, Nancy K Rollins4, and Hao Huang1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 2Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3Philips Healthcare, Cleveland, Ohio, United States, 4Radiology, Children's Medical Center, Dallas, Texas, United States

Cerebral blood flow (CBF) couples to neural activity and can be used to characterize normal brain development. The 3rd trimester is characterized with the rapid brain growth. However, little is known about spatiotemporal changes of CBF of the human brains during this period. We hypothesized CBF dynamics is regionally heterogeneous in the 3rd trimester. In this study, ASL was used for quantifying regional CBF. We aim to acquire highly reproducible and well validated ASL data of perinatal brains in the 3rd trimester with sequence optimization and explore the CBF dynamics during this period.

1735.   Resting-state functional MRI for evaluation of brain development from childhood to young adulthood
Mengxing Wang1, Jing Zhang1, Guohua Shen1, Jilei Zhang1, Kaihua Zhang1, Guang Yang1, and Xiaoxia Du*1
1Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai, Shanghai, China

We investigated the developmental aspects of local intrinsic activity, functional connectivity (FC) from childhood to young adulthood using resting-state functional MRI. There were three groups participated in this study: 20 children, 20 adolescents and 23 young adults. The amplitude of low-frequency fluctuation (ALFF) significant changes were mainly in frontal lobe, limbic lobe and cerebellum posterior lobe among three groups. The FC difference were in frontal lobe (superior, inferior and medial frontal gyri), cerebellum posterior lobe, parietal lobe (inferior parietal lobule and postcentral gyrus), as well in insula, caudate and anterior cingulate among three groups.

1736.   Development of cortical hubs in childhood and adolescence: a graph theoretical analysis in fMRI
Benjamin R Morgan1, George M Ibrahim1,2, Wayne Lee1, and Margot J Taylor1,2
1Hospital for Sick Children, Toronto, Ontario, Canada, 2University of Toronto, Toronto, Ontario, Canada

Whole-brain graph theoretical analysis was used in resting state fMRI data to identify brain regions that become stronger network hubs with age. 104 healthy subjects between the ages of 7 and 22 years were scanned and their EC maps were correlated with age. Non-parametric testing revealed that the posterior cingulate and ventromedial prefrontal cortices become significantly stronger hubs with age, while the frontal lobes and subcortical structures become significantly weaker hubs during a critical period of development. EC-based developmental analyses are a novel approach to evaluating network development and may provide further insight into areas of vulnerability for developmental delay.

1737.   Exploring The Mechanism of Emotional Imagery in Adolescence with fMRI
Marta Re1, Barbara Tomasino2, Carolina Bonivento1, Filippo Arrigoni3, Matteo Balestrieri1, and Paolo Brambilla1
1RUBIN, ICBN, University of Udine and University of Verona, Udine, Italy, 2Scientific Institute, IRCCS Eugenio Medea, San Vito al Tagliamento, Pordenone, Italy, 3Neuroimaging, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy

Mental imagery strongly influences the experience of emotion and many psychological disorders manifest distressing abnormalities in mental imagery. During adolescence, neurocognitive development impacting mental imagery processes may moderate its relationship with clinically-relevant emotional symptoms that could affect mental imagery. The aim of this work is to use fMRI to explore the networks underlying emotional imagery and to do this during the adolescence by exploring the interaction between the emotional and motor imagery by using a letter detection task acting as a control.

1738.   Early high b-value diffusion MRI of the preterm infant brain highlights radial organisation of the developing cortex
Kerstin Pannek1, Joanne George1, Paul Colditz1, Roslyn Boyd1, and Stephen Rose2
1The University of Queensland, Brisbane, Queensland, Australia, 2The Australian E-Health Research Centre, CSIRO, Brisbane, Queensland, Australia

Diffusion MRI is a promising tool for assessing brain maturation in preterm infants. In preterm infants scanned between 30 to 33 weeks postmenstrual age, we investigated the impact of the diffusion acquisition scheme on the resulting diffusion measures. A higher b-value led to increases in diffusion anisotropy in cortical grey matter, while anisotropy remained largely unchanged in white matter. High b-value diffusion MRI may provide unique insights into cortical development in prematurely born infants.

1739.   Dynamics of tract level diffusion kurtosis metrics of perinatal brain white matter from 32 to 40 gestational weeks
Zihao Zhang1,2, Austin Ouyang3, Tina Jeon3, Rong Xue4, and Hao Huang5
1Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, Beijing, China, 2University of Chinese Academy of Sciences, Beijing, Beijing, China, 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 4Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, 5Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, China

From early 3rd trimester to around the birth, increased myelination and axonal density take place in brain white matter (WM), resulting in dramatic microstructural changes. DKI-derived metrics, such as mean kurtosis (MK), reflect microstructural complexity and may provide complimentary microstructural information to that from conventional diffusion tensor imaging (DTI). In this study, we aimed to characterize the dynamics of the DKI properties at the tract level and at the core of WM tracts during the vital brain developmental stage from 32wg to 40wg, with high resolution DKI data.

1740.   Age Effect on Development of Eighteen Segmented Callosal Fibers: A study using a diffusion spectrum imaging template and tract-based statistical analysis
Hui-Hsin Hu1, Yung-Chin Hsu1, Yu-Jen Chen1, Yu-Chun Lo1, Susan Shur-Fen Gau2, and Wen-Yih Isaac Tseng1
1Center for Optoelectronic Medicine, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan

Age Effect on Development of Eighteen Segmented Callosal Fibers: A study using a diffusion spectrum imaging template and tract-based statistical analysis

1741.   High-Angular Resolution Diffusion Tractography of Emerging Cerebellar Pathways from Newborns to Young Adults
Thomas J Re1,2, Kiho Im2, Michael J Paldino2, Andrea Righini3, P Ellen Grant2,4, and Emi Takahashi4
1Radiology, University of Milan, Milan, MI, Italy, 2Radiology, Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States, 3Radiology, Buzzi Children’s Hospital, Milan, MI, Italy, 4Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard University, Boston, Massachusetts, United States

This work aims to describe the evolution of the three pairs of cerebellar peduncles (CP): superior (SCP), middle (MCP), and inferior (ICP) in 62 apparently healthy developing human subjects ranging from 30 gestational weeks (GW) to 28 years (Y) old, using high angular resolution diffusion imaging (HARDI) tractography. For the MCP, two dissociated pathways were considered: 1) pathways from the rostral pons to the inferior cerebellum (MCP-1) and 2) pathways from the caudal pons to the superior cerebellum (MCP-2).

1742.   Microstructural development of human brain cerebral cortex from early 3rd trimester to around the birth with diffusion kurtosis imaging
Tina Jeon1, Austin Ouyang1, Lina Chalak2, Jonathan Chia3, Muraleedharan Sivarajan2, Greg Jackson2, Nancy Rollins4, and Hao Huang1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 3Philips Medical Systems, Dallas, Texas, United States, 4Department of Radiology, Children's Medical Center at Dallas, Dallas, Texas, United States

From early 3rd trimester to around the birth, active cellular and molecular processes take place in the human brain cerebral cortex, resulting in dramatic microstructural changes. Diffusion kurtosis imaging (DKI) is capable of characterizing restricted water diffusion in the brain and has been applied in normal, developmental and pathological states. In addition, DKI has been shown to be a more sensitive method than conventional DTI to quantify gray matter microstructural changes in adults. In this investigation, we aim to characterize regional changes in the cortical microstructure from early 3rd trimester to around the birth with DKI.

1743.   What new do we learn with Myelin Water Fraction in infant white matter bundles in comparison with other MRI parameters?
Sofya Kulikova1, Lucie Hertz-Pannier1, Ghislaine Deahene-Lambertz2, Cyril Poupon3, and Jessica Dubois2
1UMR 663 Neurospin/UNIACT, INSERM-CEA, Gif-sur-Yvette, France, 2UMR 992 Neurospin/UNICOG, INSERM-CEA, Gif-sur-Yvette, France, 3Neurospin/UNIRS, CEA-Saclay, Gif-sur-Yvette, France

Conventional MRI/DTI parameters provide only indirect measures of the myelin content. Here we described the maturation of the white matter bundles in infants (3 - 21 weeks) using Myelin Water Fraction (a more direct myelin measure), and compared it with other parameters (quantitative qT1 and qT2 times, fractional anisotropy FA, mean , longitudinal λ║ and perpendicular λ┴ diffusivities). All parameters demonstrated asynchronous changes with age across different bundles. However, MWF was the most accurate in describing maturation asynchrony as it revealed more maturational relationships between the bundles and didn’t violate the a priori known maturational relationships.

1744.   Predicting Myelin Content from Functional Connectivity in the Developing Brain
Jonathan O'Muircheartaigh1,2, Douglas C Dean III2, Lindsay Walker2, Holly Dirks2, Nicole Waskiewicz2, Irene Piryatinsky2, Orla Doyle1, and Sean Deoni2
1Department of Neuroimaging, King's College London, London, United Kingdom, 2Department of Engineering, Brown University, Providence, Rhode Island, United States

Resting state fMRI is increasingly being used in developmental neuroimaging as it can be used during natural sleep in young infants and toddlers. However, the developmental trajectory of fMRI connectivity in this young age range is unclear as is its relationship with structural connectivity. Here we interrogate the typical trajectory of functional connectivity and it's relationship with a quantitative marker of myelin, the myelin water fraction, in a large cohort of 80 infants and young children aged 3 to 54 months. We indicate a linear relationship between myelination and functional connectivity.

1745.   In vivo assement of neurite density in the preterm brain using diffusion magnetic resonance imaging
Serena J Counsell1,2, Hui Zhang3, Emer Hughes1,2, Heather Steele1, Nora Tusor1,2, Gareth Ball1,2, Antonios Makropoulos1,2, Daniel C Alexander3, Joseph V Hajnal1,2, and A David Edwards1,2
1Centre for the Developing Brain, King's College London, London, London, United Kingdom, 2Division of Imaging Sciences & Biomedical Engineering, King's College London, London, London, United Kingdom, 3Dept of Computer Science & Centre for Medical Image Computing, University College London, London, United Kingdom

Preterm birth results in dysmaturation of cerebral grey and white matter (WM). Our aims were to assess neurite density index (NDI) in WM and thalamus in the preterm brain at term equivalent age. We studied 44 preterm infants, median (range) GA at birth 30 (24+2–32+5) and post-menstrual age (PMA) at scan 42+1 (38+3–47+1) weeks. Diffusion MRI was acquired in 2 shells; b value 750 s/mm2 , 32 directions and b value 2500 s/mm2, 64 directions at 3T. Our initial results suggest that neurite density index is more sensitive than fractional anisotropy to WM microstructural changes associated with maturation.

Rosita Shishegar1,2, Joanne M. Britto3, and Leigh A. Johnston1,3
1Electrical and Electronic Engineering, University of Melbourne, Melbourne, VIC, Australia, 2NICTA Victoria Research Laboratory, Melbourne, VIC, Australia, 3Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia

A quantitative assessment of cortical gyrification through-out development is necessary for complete understanding of normal brain development and neuro-developmental disorders. MRI has been widely used in the computation of gyrification indices (GIs). The slice direction, however, is known to influence GI. We present a modified GI computed using the Laplace Beltrami (LB) operator, which uses the intrinsic geometry of the cortex, rather than being constrained by slice orientation. Cortical folding is quantified using eigenvalues of the LB operator. We demonstrate that LB-based metrics are useful measures of cortical gyrification and complexity across key developmental time-points in the fetal sheep brain.

1747.   4D Modeling of Infant Brain Growth in Down’s Syndrome and Controls from longitudinal MRI
Clement Vachet1, Heather C. Hazlett2,3, Joseph Piven2,3, and Guido Gerig1
1Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States, 2Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, NC, United States, 3Department of Psychiatry, University of North Carolina at Chapel Hill, NC, United States

Longitudinal infant brain MRI is used to assess subject-specific brain growth trajectories and to calculate normative data. A 4D registration/segmentation framework jointly segments brain tissue at all time-points, and thus tackles the challenging age-specific MRI tissue contrast. Nonlinear mixed-effect modeling of full-brain and lobar tissue volumes results in statistical growth models presented as average trajectories with confidence bounds. Procedures were applied to 13 control and 4 Down’s syndrome subjects, with imaging at 6, 12 and 24 months. Results show significant differences in gray but not white matter. Lobe-specific analysis reveals the complex, nonlinear growth difference pattern not reported elsewhere.

1748.   Average probabilistic brain atlases for post-mortem newborn and fetal populations and application to tissue segmentation
Eliza Orasanu1, Andrew Melbourne1, M. Jorge Cardoso1, Marc Modat1, Andrew M. Taylor2, Sudhin Thayyil3, and Sebastien Ourselin1
1Centre of Medical Image Computing, University College London, London, United Kingdom, 2Centre for Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, United Kingdom, 3University College Hospital, London, United Kingdom

Segmentation of the fetal and neonatal brain magnetic resonance (MR) imaging is useful for understanding both normal and abnormal brain development, however it is challenging due to post-mortem artefacts and changes in T1 and T2 tissue values after death. In this paper we create average probabilistic brain atlases for newborn and fetus populations and use them for the automatic segmentation of further subjects with similar morphology from the same study. We compare them with manual segmentations, obtaining good agreement. This paper is the first to successfully generate post-mortem brain atlases from MR images of neonates and fetuses fully automatically.

1749.   Pyruvate to lactate metabolism with age in normal mice measured by hyperpolarized 13C
Yiran Chen1, Robert Bok1, Subramanian Sukumar1, Xin Mu1, Ann Sheldon2,3, A James Barkovich1, Donna M Ferriero2,3, and Duan Xu1,4
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Department of Neurology, University of California San Francisco, CA, United States, 3Department of Pediatrics, University of California San Francisco, CA, United States, 4Joint UCSF/UC Berkeley Graduate Group in Bioengineering, CA, United States

In this study, we applied dynamic nuclear polarization (DNP) technique to investigate C1 labeled 13C pyruvate to lactate conversion across maturation in mice in vivo. Normal mice were scanned starting on postnatal day 18 and repeated every 10 days. Experiments were conducted on a 14.1T NMR spectrometer with real-time metabolic imaging simultaneously with injection of hyperpolarized pyruvate. We found that lactate level was significantly higher at younger ages, and stabilized around P30. The level of lactate was also independent to the polarization or pyruvate level.


Fetal & Pediatric Neuroimaging

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1750.   Applications of Magnetic Resonance Imaging for Prognosis of Fetal Neuropathology
Smitha Ravindran Saraswathi1, Thripthi Shetty1, Pavan Poojar1, Sona Pungavkar2, and Sairam Geethanath1
1Medical Imaging Research Center, Dayananda Sagar Institutions, Bangalore, Karnataka, India, 2Department of Radiology, Dr.Balabhai Nanavathi Hospital, Mumbai, Maharashtra, India

Fetal Magnetic Resonance Imaging is a vital tool for determining fetal neuropathologies than any other imaging modalities due to better soft tissue contrast. After analyzing the the eighty datasets and consultation with the radiologist we have come to a conclusion that these datasets represent four neuropathologies such as Occipital Encephalocele ,Occipital meningocele, Sacral meningocele, Lumbar meningocele.These datasets are subjected to manual segmentation to find out the extend of protrusion of the abnormality to help the doctors to take timely decision whether to do fetal surgery, perform the surgery after delivery or to terminate in case of high risk pregnancies.

1751.   A 3D surface based correlation analysis of the putamen and thalamus in premature neonates
Yi Lao1, Yalin Wang2, Jie Shi2, Rafael Ceschin3, Marvin D. Nelson1, Ashok Panigrahy3, and Natasha Lepore1
1Department of Radiology, University of Southern California and Children's Hospital, Los Angeles, Los Angeles, California, United States, 2School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Temp, Arizona, United States, 3Department of Radiology, Children's Hospital of Pittsburgh UPMC, Pittsburgh, pennsylvania, United States

Finding the neuroanatomical correlates of prematurity is vital to understanding which structures are affected, and in designing treatments. Studies revealed that deep gray matter alterations, notably on the thalamus, are important indicators of prematurity. However, little is known about the association of altered thalamic development with other deep gray matter disturbances, and no study was able to localize the association within the sub-nuclei of the gray matter. Here, using brain structural MRI, we tested the hypothesis that thalamic alterations due to prematurity is associated with that of the ventral striatum. We performed a novel 3D correlation of the thalamus and its allied ventral striatum structures using 17 preterm and 19 term-born neonates, in terms of the surface determinant and radial distance. The results are then compared with previously found group differences in the same dataset, to obtain a more comprehensive assessment of the deep gray matter involvement in premature injuries. Our results showed that some of the regional abnormalities on the thalamus are associated with the alterations in ventral striatum, possibly due to the disturbance on the development of the shared cortical-striatum-thalamus pathway. These findings extend knowledge gained from traditional volume based analyses of neonates in the literature, and provide anatomical evidence to the concept of 'encephalopathy of prematurity'.

Hye-Jin Jeong1, So-Yeon Shim2, Joon-Sup Jeong1, Young-Bo Kim1, and Zang-Hee Cho1
1Neuroscience Research Institute, Gachon University, Incheon, Korea, 2Division of Neonatology, Ewha Womans University Mokdong Hospital, Seoul, Korea

Preterm infants have an increased risk of future neurodevelopmental impairmentthat is correlated with the degree of prematurity at birth. Diffusion tensor imaging (DTI) enables the visualization and quantitative characterization of white matter in vivo. Especially tract-based spatial statistics (TBSS) performed spatial normalization for group analysis in brain white matter. In this study, we performed analyses of white matter development between full-term infants and preterm infants at equivalent age using TBSS.

1753.   White Matter Microstructure in Moderate and Late Preterm Infants assessed using Tract-Based Spatial Statistics
Deanne K Thompson1,2, Claire E Kelly1, Alexander Leemans3, Lillian Gabra Fam1,4, Marc L Seal1,4, Lex W Doyle1,5, Peter J Anderson1,4, Alicia J Spittle1,5, and Jeanie LY Cheong1,5
1Murdoch Childrens Research Institute, Melbourne, VIC, Australia, 2Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 4Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia, 5Royal Women's Hospital, Melbourne, VIC, Australia

Few studies have investigated the effects of moderate or late preterm birth (MLPT, 32+0-36+6 weeks’ gestation) on brain development using MRI. This study compared whole brain white matter microstructure between 185 MLPT infants and 70 term-born controls (born ≥37 weeks’ gestation) at term-equivalent age using Tract-Based Spatial Statistics analysis of diffusion tensor data. There were widespread regions of lower fractional anisotropy and higher axial, radial and mean diffusivities in MLPT infants than controls, suggesting that white matter microstructure is altered in MLPT infants compared with controls. MLPT infants may be at higher risk of altered white matter development than previously recognised.

Microstructural development of the corpus callosum ‘catches up’ between term and 7 years in children born <30 weeks’ gestation or <1250 g
Deanne K Thompson1,2, Loeka Van Bijnen1, Katherine J Lee1,3, Alexander Leemans4, Leona Pascoe1, Shannon E Scratch1, Christopher Adamson1, Gary F Egan5,6, Lex W Doyle7, Terrie E Inder8, and Peter J Anderson1,3
1Murdoch Childrens Research Institute, Melbourne, Victoria, Australia, 2Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia, 3Paediatrics, University of Melbourne, Melbourne, Victoria, Australia, 4Imaging Science Institute, Utrecht, Netherlands, 5Biomedical Imaging, Monash University, Melbourne, Victoria, Australia, 6florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia, 7Royal Women's Hospital, Melbourne, Victoria, Australia, 8Brigham and Women's Hospital, Boston, Massachusettes, United States

It is unknown whether early alterations to the corpus callosum (CC) persist or resolve over time. We aimed to determine whether longitudinal CC development occurs faster or slower in preterm children compared with term controls; and whether longitudinal CC development is associated with neurodevelopmental functioning. Diffusion tractography was performed at term-equivalent and 7 years in 76 very preterm and 16 controls. Preterm CC tract volume increased and diffusivity decreased more over time than controls. Greater reduction in diffusivity measures over time was associated with better cognitive and motor functioning. Thus corpus callosum development ‘catches up’ after early insult.

Apparent Fibre Density Abnormalities in Adolescents Born Extremely Preterm: Moving Beyond the Diffusion Tensor
David Raffelt1, Jeanie LY Cheong2,3, Farnoosh Sadeghian1, Deanne K Thompson3,4, Peter J Anderson3,5, Lex W Doyle2,3, and Alan Connelly1,6
1Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia, 2Neonatal Services, Royal Women’s Hospital, Melbourne, VIC, Australia, 3Victorian Infant Brain Studies, Murdoch Childrens Research Institute, Melbourne, VIC, Australia, 4Developmental Imaging, Murdoch Childrens Research Institute, Melbourne, VIC, Australia,5Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia, 6Department of Medicine, University of Melbourne, Melbourne, VIC, Australia

Preterm birth is associated with increased risk of health and developmental problems in childhood and adolescence. White matter abnormalities have been reported previously in preterm born adolescents using the diffusion tensor, however these results are difficult to interpret in regions with crossing fibres. In this study we investigate preterm born adolescence using Apparent Fibre Density (AFD), a quantitative measure that is tract specific, even in voxels with multiple fibres. When compared to term-born controls, we observed a decrease in AFD in numerous white matter tracts. We also observed significant AFD correlations with a range of perinatal factors.

1756.   Functional connectivity differences in full-term and preterm at term equivalent age newborns.
Lara Lordier1, Frederic Grouiller2, Dimitri Van De Ville3, François Lazeyras2, and Petra S. Hüppi1
1Division of development and Growth, Department of pediatrics, Geneva university hospital, Geneva, Geneva, Switzerland, 2Departement of radiology and medical informatics, University of Geneva, Geneva, Switzerland, 3Institute of bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland

There is a growing evidence corroborating the hypothesis that resting-state functional connectivity is related to both underlying structural connectivity and modulated by the development of white matter pathways occurring early in brain development that are maturing throughout childhood. In this study we compared resting state functional connectivity using a global group level ICA in 19 full term newborns and 13 preterm at term equivalent age infants to assess to which extent premature exposure to extra-uterine environment impacts on functional connectivity. The results show significant differences in functional connectivity between a sensory area (auditory network) and parts of the salience networks.

1757.   Altered structural connectivity in preterm children: Network-based statistical analysis
Deanne K Thompson1,2, Jian Chen1, Christopher Adamson1, Richard Beare1, Zohra M Ahmadzai1, Terrie E Inder3, Lex W Doyle4, Marc Seal1, and Peter J Anderson1
1Murdoch Childrens Research Institute, Melbourne, Victoria, Australia, 2Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia, 3Brigham and Women's Hospital, Boston, Massachusettes, United States, 4Royal Women's Hospital, Melbourne, Victoria, Australia

The impact of prematurity on structural connectivity is not yet understood. The aims of this study were to compare network measures of structural connectivity between very preterm (VP) and full-term children, and to determine if network measures were correlated with gestational age in the VP group. Results indicated that the brains of VP children had altered network topography compared with full-term controls. Our findings suggest that the VP brain has a less integrated and more segregated brain than full-term 7 year olds. This may contribute to the poor neurodevelopmental outcomes that are common in very VP children compared with controls.

1758.   BOLD fMRI and fcMRI in the Pediatric Brachial Plexus Injury Population: Evaluating Cortical Plasticity
Rupeng Li1, Jacques A Machol IV2, Nicholas A Flugstad2, Ji-Geng Yan2, James S Hyde1, and Hani S Matloub2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States

With our development of touchless air-puff stimulator, fMRI and fcMRI of peripheral sensory can be studied in both pediatric population and adults conscious or asleep. Following BPI, dramatic CNS plasticity happens that results in both local and large scale changes in the sensory network.

1759.   Altered structural brain networks in children with Asperger syndrome: a DTI-based connectome study
Haoxiang Jiang1,2, Yanni Chen2, Qinli Sun1,3, Xianjun Li3, Mengye Lv3, Yang Song1, and Jian Yang1,3
1Department of Diagnostic Radiology, The First Hospital of Medical School,Xi'an Jiaotong University, Xi'an, Shannxi, China, 2Department of Diagnostic Radiology, Xi'an Children Hospital, Xi'an, Shannxi, China, 3Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shannxi, China

The aim of this study is to investigate the altered structural brain networks based on diffusion tensor imaging (DTI ) in children with Asperger syndrome(AS). 22 boys with AS and 18 typically developing(TD) children with matched age and sex were collected. The results of this study indicated the topological alterations of white matter network in AS group compared to the TD group. Meanwhile, network-based statistic result displayed disrupted connected components in the right hemisphere in AS group, especially those long-range connections within the posterior part of the brain cortex and thalamus and limbic system. DTI-based brain network analysis can provide more objective estimation of brain abnormal connectivity.

1760.   Brain Templates for Neonates with Congenital Heart Defects: Preliminary Results from an International Consortium
Jue Wu1, Peter Schwab2, Arastoo Vossough2, James Gee1, and Daniel Licht2
1University of Pennsylvania, Philadelphia, PA, United States, 2Children's Hospital of Philadelphia, PA, United States

The International Consortium on CHD Neonatal Brain MRI was established to coordinate efforts to tackle the problem of MR data normalization. We demonstrate the feasibility of normalizing a set of 467 highly heterogeneous multi-center multi-scanner MR images by using high-deformation image registration to warp individual images to specific templates. The construction of specific templates based on site, age or cardiac diagnosis allows researchers to investigate the abnormal brain development in a more homogenous subset and potentially increase the specificity and reliability of the findings.

1761.   Initial application of diffusional kurtosis imaging (DKI) in brain development of preterm infants and evaluation of DKI in hypoxic-ischemic encephalopathy
Jingjing Shi1, Wenzhen Zhu1, and Zhenyu Zhou1
1Department of Radiology, Tongji Hospital,Huazhong Univercity of Science and Technology, Wuhan, Hubei, China

HIE can lead to developmental disorders of the nervous system, and seriously affect the quality of life of the survived premature children.Diffusion kurtosis imaging (DKI),as a new diffusion imaging technique,may provide more information to us about the microstructural abnormalities of HI injury.

1762.   Radiological evaluation of quiet T1-weighted PETRA in comparison with routine brain MPRAGE in pediatric patients
Noriko Aida1, Kumiko Nozawa1, Yuta Fujii1, Koichiro Nomura1, Tetsu Niwa1, Masahiko Sato2, Koki Kusagiri2, Yasutake Muramoto2, Yuichi Suzuki2, Katsutoshi Murata3, Matthew Nielsen3, David Grodzki4, and Takayuki Obata5
1Radiology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 2Radiological technology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 3Research & Collaboration, Imaging &Therapy System, Siemens Japan, Tokyo, Japan, 4Magnetic Resonace, Siemens Healthcare, Erlangen, Bavaria, Germany,5Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan

Clinical efficacy of a prototype T1-weighted PETRA was prospectively evaluated compared to MPRAGE in 56 sedated pediatric patients.@PETRA requires very limited gradient activity and allows for inaudible scanning. Only 4.8 dB(A) higher than the background acoustic noise was measured in T1-PETRA in contrast to 34.8dB(A) in MPRAGE. The ICC scores of degree of myelination in all but one anatomical area for two readers indicated excellent agreement. T1-PETRA is very quiet and has good image quality by using about one minute more scan time, and it could be substituted for MPRAGE in order to provide gentler scans to pediatric patients.

1763.   Quiet SWI versus conventional SWI: Radiological evaluation in pediatric patients
Noriko Aida1, Kumiko Nozawa1, Yuta Fujii1, Tetsu Niwa1, Koichiro Nomura1, Masahiko Sato2, Koki Kusagiri2, Yasutake Muramoto2, Yuichi Suzuki2, Katsutoshi Murata3, Matthew Nielsen3, David Grodzki4, and Takayuki Obata5
1Radiology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 2Radiological technology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 3Research & Collaboration, Imaging &Therapy System, Siemens Japan, Tokyo, Japan, 4Magnetic Resonace, Siemens Healthcare, Erlangen, Bavaria, Germany,5Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan

Clinical efficacy of a prototype quiet SWI (qSWI) was prospectively evaluated compared to the conventional SWI (cSWI) in 57 sedated pediatric patients. qSWI sequence with optimized gradients was used in order to reduce acoustic noise and it was measured 8.8 dB(A) less than that of cSWI. ICC scores in all evaluated veins for two readers indicated good or moderate agreement. qSWI provided image quality that was almost identical to that of cSWI and it produced less acoustic noise by using slightly more scan time, and could be substituted for cSWI in order to provide gentler scans to pediatric patients.

1764.   Segmentation-based MRI templates for pre-term and full-term newborns
Frédéric Grouiller1, Laura Gui2, Gwénaël Birot3, Alexandra Darqué2, Lara Lordier2, Petra Hüppi2, and François Lazeyras1
1Department of Radiology and Medical Informatics, Geneva University Hospital, Geneva, Switzerland, 2Division of Development and Growth, Department of Pediatrics, Geneva University Hospital, Geneva, Switzerland, 3Functional Brain Mapping Laboratory, University of Geneva, Geneva, Switzerland

Due to the absence of myelin at birth, tissues properties of the neonatal brain are strongly different of the adult’s brain. Realistic newborn head model is required to compute accurate EEG source imaging. We built segmented templates of preterm and full-term newborns’ brain using segmentation of individual structural MRI. Electrical conductivity can be assigned to each type of tissue to build a realistic model for EEG source localization. These templates and their corresponding tissue probability maps could also be used for tissue masking or as prior for subsequent analyses.

1765.   Comparing FreeSurfer with manual segmentation in the basal ganglia and thalamus of 7 year old children
Wai Yen Loh1,2, Zohra M Ahmadzai2,3, Lillian Gabra Fam2,3, Alan Connelly1, Alicia J Spittle2,4, Katherine J Lee2,3, Terrie E Inder5, Jeanie LY Cheong2,4, Lex W Doyle2,4, Peter J Anderson2,3, and Deanne K Thompson1,2
1The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia, 2Murdoch Childrens Research Institute, Melbourne, VIC, Australia, 3Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia, 4Royal Women's Hospital, Melbourne, VIC, Australia, 5Brigham and Women's Hospital, Boston, MA, United States

To validate FreeSurfer’s segmentation method of the basal ganglia and thalamus in a paediatric population, FreeSurfer’s semi-automated segmentations were compared with manual segmentations in a 7 year-old cohort comprised of healthy and preterm children. The intraclass correlation coefficient scores for consistency were well-above 0.7 for all structures except the nucleus accumbens and right caudate. Similarly, Bland-Altman plots indicated that there was a consistent bias between both methods. This study suggests that while FreeSurfer is useful in comparing basal ganglia and thalamus volume differences between groups, it may not be accurate in obtaining exact volumes for a paediatric population.

1766.   In-vivo 3D Magnetic Resonance Volumetric Analysis of Fetal Cerebellum: From normal to pathology (unilateral cerebellar hypoplasia)
Martina Gianoni1,2, Marie Schaer3, Sébastien Tourbier1,2, Yvan Vial4, Maud Cagneaux5, Patric Hagmann1, Reto Meuli1, Laurent Guibaud5, and Meritxell Bach Cuadra1,2
1Radiology Department, University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Vaud, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Vaud, Switzerland, 3University of Geneva, Switzerland, 4Department de Gynécologie-obstétrique, University Hospital Center (CHUV) and University of Lausanne (UNIL), Vaud, Switzerland, 5Radiology Department, Hôpital Femme, Mère et Enfant, Lyon, France

MRI is increasingly being used for the fetal central nervous system studies in vivo. Fast MR acquisition schemes in combination with advanced image processing reconstruction methods allow the quantitative studies of cerebellar volume of the fetus in-utero based on high resolution MRI. In this study we estimated the cerebellar volume of 9 healthy subjects coming from different sites. Their volumes match the previously reported results. We also study one case with unilateral cerebellar hypoplasia, showing that the pathological hemisphere is an outlier of the healthy hemispheric volumes regression over the gestational age.

1767.   Fully automated estimation of brain volumes in post-mortem newborns and fetuses
Eliza Orasanu1, Andrew Melbourne1, M. Jorge Cardoso1, Marc Modat1, Andrew M. Taylor2, Sudhin Thayyil3, and Sebastien Ourselin1
1Centre of Medical Image Computing, University College London, London, United Kingdom, 2Centre for Cardiovascular Imaging, Institute of Cardiovascular Science, University College London, London, United Kingdom, 3University College Hospital, London, United Kingdom

Minimally invasive autopsy using post-mortem magnetic resonance imaging (MRI) can be a valid alternative to conventional autopsy in fetuses and infants. Estimation of brain weight is an integral part of autopsy, but manual segmentation of visceral organ volumes on MRI is labour intensive and unsuitable for routine clinical practice. In this paper we show that brain weight can be estimated from post-mortem brain MRI with a maximum error of 2% in fetuses and 11% in newborns using a fully automated technique. This technique can be used in clinical practice and may increase the uptake of minimally invasive autopsy.

1768.   Optimized Pediatric Suite with head array adjustable for patients 0-5 yrs of age
Modhurin Banerjee1, Clyve Konrad Follante1, Aleksey Zemskov1, Rodney Bills1, Mark Giancola,1, Lakshan Nanayakkara1, Sarah Ortman1, Jessica Buzek2, Taracila Victor1, Kolman Juhasz3, Stephen Scurria1, Thomas Grafendorfer4, Paul Calderon5, Vijay Alagappan6, Steve Lee1, Shreyas Vasanawala7, and Fraser Robb1
1GE, Aurora, OH, United States, 2GE, WI, United States, 3Vita-Mix Corp, OH, United States, 4GE, CA, United States, 5Diamante Engineering, CA, United States, 6Softgel Healthcare, TN, India, 7LPCH, CA, United States

We illustrate the evolution of a previously featured 32-channel pediatric suite coil system. The system now comprises (up to) 80 multiplexed elements: a multi-degree of freedom adjustable 28 element head coil; a 28 element uniform posterior array in a rigid base; and a two-part foamed anterior array consisting of 2 subplates/subarrays - each subarray consisting of either 12 or 16 (uniform) elements. The system gives superior SNR performance and parity acceleration factor relative to extant adult-based systems. The mechanical and aesthetic design has matured, yielding a product that adroitly enhances the workflow and patient experience for the 0-to-5 year population.

1769.   Brain differences in toddlers at risk of ASD
Lindsay Walker1,2, Douglas C Dean III2, Jonathan O’Muircheartaigh3, Irene Piryatinsky2, Nicole Waskiewicz2, Holly Dirks2, and Sean CL Deoni2
1Center for Biomedical Engineering, Brown University, Providence, RI, United States, 2Advanced Baby Imaging Lab, Brown University, Providence, RI, United States, 3King's College London, Institute of Psychiatry, London, United Kingdom

Autism spectrum disorder (ASD) is marked by significant behavioural, social and cognitive deficits. Early intervention is key in allowing children with ASD to reach their full potential, necessitating studies of children prior to typical age of diagnosis. In this work a small cohort of at-risk children were identified from a longitudinal imaging study of typical brain development. Brain myelin content was compared between this group and an age and gender-matched group of typically developing peers from the same study. Brain differences were found that are consistent with a theory of atypical brain developmental trajectories in ASD.

1770.   Gradient Echo Plural Contrast Imaging in Studying Neonatal Brain Development: Preliminary Results
Jie Wen1, Jeffrey J. Neil1,2, Joseph Ackerman Jr.1,2, Jie Luo3, Terri E. Inder2, and Dmitriy A. Yablonskiy1
1Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, United States, 2Department of Pediatrics Newborn Medicine, Washington University in St. Louis, St. Louis, MO, United States, 3Massachusetts Institute of Technology, MA, United States

Different methods have been used in the past to study brain development. Gradient Echo Plural Contrast Imaging (GEPCI) is a technique allowing generation of naturally co-registered images with various contrasts within a single MRI scan. The quantitative T2* and frequency maps derived from GEPCI show stronger contrast and more details compared with conventional clinical images. Here, we demonstrate the feasibility of applying GEPCI to evaluation of neonatal brain in health and disease. Multi-contrast GEPCI images provide multi-perspective means to explore neonatal brain development and injury quantitatively. The quantitative R2* distribution analysis shows substantial differences between term and preterm borne neonates.

1771.   Improved Fat Suppression Homogeneity of mDIXON TSE Total Spine Imaging compared to SPIR Fat Saturation for Post-Contrast T1-weighted Imaging at 3.0T
Jeffrey H. Miller1, Amber Pokorney1, Padmaja Naidu1, Holger Eggers2, Michael Schär3, and Thomas G. Perkins3
1Phoenix Children's Hospital, Phoenix, AZ, United States, 2Philips Research, Hamburg, Germany, 3Philips Healthcare, Cleveland, OH, United States

Homogeneous fat suppression is often challenging in large field of view post contrast MRI of the spine. An alternative to traditional spectral fat saturation or IR fat suppression are the Dixon chemical shift based fat suppression techniques. Modified DIXON (mDIXON) was compared with spectral saturation (SPIR) images at 3T of the total spine post contrast using sagittal 2D T1-TSE . A statistically significant difference in image quality was found, with mDIXON demonstrating significantly better image quality and fat suppression then SPIR. The use of mDIXON fat suppression eliminates patient-to-patient variations in image quality of total spine MRI at 3T.

1772.   Effect of mutation location on Duchenne brain morphology
Nathalie Doorenweerd1,2, Eve Dumas1, Chiara Straathof3, Erik Niks3, Beatrijs Wokke3, Janneke van den Bergen3, Debby Schrans4, Erik van Zwet5, Mark van Buchem1,2, Andrew Webb1, Jos Hendriksen4,6, Jan Verschuuren3, and Hermien Kan1,2
1Radiology, Leiden University Medical Center, Leiden, Zuid Holland, Netherlands, 2Leiden Institute for Brain and Cognition, Leiden, Zuid Holland, Netherlands, 3Neurology, Leiden University Medical Center, Leiden, Zuid Holland, Netherlands, 4Department of Neurological Learning Disabilities, Kempenhaeghe Epilepsy Centre, Heeze, Noord Brabant, Netherlands, 5Medical Statistics, Leiden University Medical Center, Leiden, Zuid Holland, Netherlands, 6Neurology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands

In Duchenne muscular dystrophy (DMD), patients with a mutation downstream of exon 44 on the DMD gene have an increased risk of neuropsychological and behavioral problems. Using quantitative MRI, we show significantly smaller intracranial, total brain and grey matter volume in patients with a mutation downstream of exon 44 compared to controls. Mean diffusivity increases were also more pronounced in this patient group compared to controls. These findings and can aid in determining the underlying mechanism of cognitive or behavioral dysfunction in DMD.


Normal Brain Anatomy

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1773.   A new way of constructing edge weights of a structural connectivity matrix by considering direct and indirect connections of the fiber tracts
Sung-Chieh Liu1, Yao-Chia Shih1, Yu-Jen Chen1, and Wen-Yih Isaac Tseng1
1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taipei, Taiwan

We presented a novel method to measure structural connectivity between pairs of brain regions based on cortical/subcortical parcellation and tract bundles, and applied the conductance concept to build edge strengths for connectivity matrices, including direct and indirect structural connections. We assessed the reliability of structural connectivity matrices in a group of 20 healthy subjects. We found that the summation of direct and indirect connections built a structural connectivity matrix that involved the majority of the known functional connectivity in the brain. Moreover, the connectivity matrices of individual subjects became highly correlated when all the direct and indirect connections were considered.

1774.   Structural MRI measures can be affected by brain activity during image acquisition
Florian Schubert1, Ralf Mekle1, Elisabeth Wenger2, Nils C. Bodammer2, Bernd Ittermann1, Jürgen Gallinat3, and Simone Kühn2
1Physikalisch-Technische Bundesanstalt, Berlin, Germany, 2Max Planck Institute for Human Development, Berlin, Germany, 3Charité Universitätsmedizin, Berlin, Germany

We tested the assumption that structural brain MR images are not affected by concurrent brain function during acquisition. MPRAGE, spin echo (TIRM) and resting state fMRI were acquired at 3T, twice per subject, with eyes open (EO) and closed (EC). For MPRAGE, but not for TIRM images, voxel-based morphometry indicated larger GM volume of bilateral visual cortex for EO vs. EC. These regions overlapped with regions showing different amplitudes of low-frequency fluctuation resting-state maps for EO vs. EC. The apparent morphometric effects on MPRAGE images may result from MPRAGE’s sensitivity to T2*. Structural images should be acquired with the subjects’ eyes closed.

1775.   Weekly Scanning of a Normal Control over Four Years
Craig K Jones1,2, Peter A Calabresi3, Peter B Barker1,2, and Peter CM van Zijl1,2
1Dept of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F.M. Kirby Research Center, Kennedy Krieger Institute, Baltimore, MD, United States, 3Dept of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Numerous studies report on serial scans over short periods of time or infrequent scans over a long period of time but there are no published accounts of frequent serial scanning for a long term. Here, MPRAGE, dual-echo-T2, FLAIR, DTI and magnetization-transfer-weighted scans were acquired weekly in a normal control for four years. White matter, gray matter, cortical gray matter and CSF volumes were calculated. This data will be useful to validate the use of these sequences for tracking changes in signal intensity and brain volumes over time in patient groups with subtle neurological disorders and for treatment response.

Regional cerebral blood volume (rCBV) bias voxel-based morphometry (VBM) in an animal study
Dirk Ernst Cleppien1, Lei Zheng2, Claudia Falfan-Melgoza1, Barbara Vollmayr3,4, Wolfgang Weber-Fahr1, and Alexander Sartorius3
1RG Translational Imaging, Department of NeuroImaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany,2Experimental Radiation Oncology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 3Department of Psychatry and Pschotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 4RG Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany

Neuroplastic effects of the brain are able to be visualized by magnetic resonance imaging techniques like voxel-based morphometry (VBM). One possible drawback could be sensitivity to reversible changes of the brain structure like regional cerebral blood volume (rCBV) changes without any underlying effect on neuroplasticity. Therefore, our hypothesis was that rCBV partially explains the variance of VBM changes. For this, we compared the VBM results analysed in two different ways, one with rCBV as a covariate per voxel and one without, in order to state the influence of rCBV on GM probability maps.

1777.   Anatomical connections of the Visual Word Form Area
Florence Bouhali1, Michel Thiebaut de Schotten1,2, Philippe Pinel3, Cyril Poupon3, Jean-François Mangin3, Stanislas Dehaene4, and Laurent Cohen1
1Brain and Spine Institute, Paris, France, 2Natbrainlab - Institute of Psychiatry, Paris, France, 3Neurospin, Paris, France, 4Collège de France, Paris, France

The visual word form area (VWFA), a region systematically involved in the identification of written words, occupies a reproducible location in the left occipito-temporal sulcus in expert readers of all cultures. Such a reproducible localization is paradoxical, given that reading is a recent invention that could not have influenced the genetic evolution of the cortex. Here, we revealed that the VWFA recycles a region of the ventral visual cortex that shows a high degree of anatomical connectivity to perisylvian language areas, thus providing an efficient circuit for both grapheme-phoneme conversion and lexical access.

1778.   Automated Segmentation of the Human Amygdala using High Angular Diffusion Imaging (HARDI) and Spectral k-means Clustering
Brian David Stirling1, Yu-Chien Wu1, Long Sha1,2, Jim Haxby1, and Paul J Whalen1
1Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States, 2Neuroscience Institute, New York University, New York, NY, United States

Despite the functional relevance and unique circuitry of each human amygdaloid subnucleus, there has yet to be an efficient imaging method for identifying these regions. The present study uses High Angular Resolution Diffusion Imaging (HARDI), high spatial resolution, and spectral k-means clustering to segment the amygdala. Clustering was performed on the similarity matrices generated from the spherical harmonic (SH) coefficients of the whole structure orientation distribution function (ODF) across 32 subjects. The results show that these methods were able to significantly segment the amygdala into 3 distinct regions: a medial region, a posterior-superior-lateral region, and an anterior-inferior-lateral region.

1779.   Correlation of 16.4T mouse models with serial blockface and immunohistochemical imaging
Andrew L Janke1, Meng Kuan Lin1, Nyoman D Kurniawan1, Robert K P Sullivan2, Richard Webb3, and Jeremy F. P. Ullmann1
1Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia, 2Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia, 3Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland, Australia

Here we correlate 16.4T MRI signal from normative and gadolinium enhanced tissue preparations with serial sectioned realigned histology and block face imaging in the normative mouse brain

1780.   Revisiting Two Exchangeable Proton Environments in Human Grey and White Matter Using Free and Restricted Exchangeable Proton (FREP) Imaging
Mitsue Miyazaki1, Cheng Ouyang1, Xiangzhi Zhou1, James B. Murdoch1, Tomohisa Okada2, Koji Fujimoto2, Aki Kido2, Yasutaka Fushimi2, and Kaori Togashi2
1Toshiba Medical Research Institute, Vernon Hills, IL, United States, 2Kyoto University, Kyoto, Japan

We revisited exchange of protons between the relatively free and restricted proton pools in macromolecule and investigated the Z-spectra acquired over a broad and symmetric frequency range (-30 KHz to +30 KHz). Then, a quartet of quantitative biomarkers, i.e., proton fractions (Ff, Fr) and spin-spin relaxation times (T2,f, T2,r) in both free and restricted proton pools, were mapped by fitting the measured Z-spectra to a simple two-Lorentzian compartment model on a voxel-by-voxel basis. The result provides a simple approach estimating fractions and T2 values of free and restricted exchangeable protons.

1781.   The preservation state of ethanol-fixated historic brain specimens revealed by quantitative MRI
Gunther Helms1, Walter J Schulz-Schaeffer2, and Renate Schweizer3
1Cognitive Neurology, Göttingen University Medical Center, Göttingen, Germany, 2Neuropathology, Göttingen University Medical Center, Göttingen, Germany,3Biomedizinische NMR ForschungsGmbH, Max-Planck-Institut für Biophysikalische Chemie, Göttingen, Germany

Four male brains preserved in ethanol for 150 years were studied at 3T by FLASH-based multi-parametric mapping at 0.6mm resolution for digital asservation. These were compared to recent specimens; an ethanol-fixated bovine brain and a formalin-fixated brain. T1-relaxation in cortex was much faster (R1=5-7 1/s) than after formalin fixation and did not show a "formalin rim". White matter exhibited sub-millimeter tubular cavities (not seen in bovine brain) leading to slower T1 relaxation than in cortex. Magnetization transfer and proton density contrast were strongly reduced. Findings are compatible with rapid extraction of cholesterol and water followed by slow macroscopic degeneration.

1782.   High resolution imaging of hippocampal internal architecture using HR-MICRA at 3T
Lawrence Ver Hoef1,2, Hrishikesh Deshpande3, Ronald Beyers4, Nouha Salibi5, and Thomas Denney4
1University of Alabama at Birmingham, Birmingham, Alabama, United States, 2Neurology, Birmingham VA Medical Center, Birmingham, Alabama, United States, 3University of Alabama at Birmingham, Birmingham, AL, United States, 4MRI Research Center, Auburn University, Auburn, AL, United States, 5Siemens Medical Solutions, Auburn, United States


1783.   Comparison between 7T T2* and 3T MTR in the in vivo human cortex.
Gabriel Mangeat1, Sindhuja T. Govindarajan2, Caterina Mainero2, and Julien Cohen-Adad1
1Biomedical institute, Ecole Polytechnique de Montreal, Montreal, Qc., Canada, 2A.A. Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, MA, United States

T2* at ultra high field MRI (7T) recently prove useful for characterising cortical myelo-architecture. However, several confounds hamper the specificity of T2*. Here, we combined T2* with magnetization transfer data (MTR) in the same cohort of healthy subjects. The goal was to assess the relationship between T2* at 7T and MTR at 3T, and show their respective sensitivity and specificity to myelin content. Data were preprocessed and then combined within a surface-based analysis framework. Average correlation between T2* and MTR was r=-0.76. Combining other metrics (T1, diffusion, T2w/T1w) within the same methodological framework could potentially bring useful insight into myelo-architecture.

1784.   Detection of epileptogenic zone and its dynamics by database-approach of resting-state BOLD-based fMRI in Brain Cloud
Tzu-chen Yeh1,2, Chou-ming Cheng3, and Jin-jie Hong3
1Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan, 2Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Taiwan,3Department of Medical Education and Research, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan

Two-thirds of patients with focal epilepsy there are no identifiable brain lesions on conventional MR imaging. Resting-state blood-oxygenation-level-dependence (BOLD) functional MRI (rs-fMRI) was proposed to detect the epileptogenic zone (EZ), irritative zone (IZ), pacemaker zone (PZ) or ictal symptomatic zone (ISZ) based on local functional connectivity of inter-ictal neuronal discharge. In this study, the database-approach of ¡§Brain Cloud¡¨ was tested using the rs-fMRI of on-site or web-site database of rs-fMRI. Correlation with electrocorticography (ECoG) was applied for verification, and time-lag functional netwrok of rs-fMRI was derived for mapping the dynamics of zones related to seizure.

1785.   Susceptibility-weighted imaging using unbalanced steady-state free precession gradient-echo imaging with multiple echoes
Jia-Chin Wade Lai1, Cheng-Chieh Geo Cheng1, and Hsiao-Wen Chung1,2
1Graduate Institute of Biomedical Electronics and Bioinformatics (BEBI), National Taiwan University, Taipei City, Taiwan, 2Department of Electrical Engineering, National Taiwan University, Taipei City, Taiwan

We investigate potential benefits of multi-echo acquisition using the unbalanced steady-state free-precession (ubSSFP) sequence on SWI application

1786.   Exploring the laminar components of the human cortex using ultra-high resolution Inversion Recovery and diffusion
Daniel Barazany1,2, Karl Zilles3, and Yaniv Assaf1
1Department of Neurobiology, Tel Aviv University, Tel Aviv, Israel, 2CUBRIC School of Psychology, Cardiff University, Cardiff, United Kingdom, 3Institute of Neuroscience and Medicine INM-1, Research Center Juelich, Jeulich, Germany

Inversion recovery (IR) MRI provide image contrasts that allow the human cortex segmentation to their subcomponents (i.e., IR-layers), based on the intrinsic T1 properties. In this work, several tissue blocks of fixed human cortex were scanned at ultra-high resolution both IR-MRI to visualize their IR layers. In addition, we also acquired different diffusion MRI modalities such as diffusion tensor imaging (DTI) and composite hindered and restricted model of diffusion (CHARMED) to explore the IR-layer diffusion characteristics and their connectivity patterns by tractography analysis.

1787.   Improved deep gray matter segmentation using anatomical information from quantitative susceptibility maps
Ferdinand Schweser1, Xiang Feng1, Rosa Mach Batlle1, Daniel Güllmar1, Andreas Deistung1, Michael G Dwyer2, Robert Zivadinov2,3, and Jürgen R Reichenbach1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 2Buffalo Neuroimaging Analysis Center, University at Buffalo SUNY, Buffalo, New York, United States, 3Jacobs Neurological Institute, University at Buffalo SUNY, Buffalo, New York, United States

Brain image segmentation followed by region-of-interest (ROI)-based analyses is a way to quantify subtle variations of MR image intensity. In this contribution we present an approach to improve the automated segmentation of deep gray matter with FIRST that relies on the incorporation of prior anatomical information from secondary image contrasts with high-contrast in the critical brain regions. The proposed technique is solely pre-processing-based and, thus, does not require modification of the actual segmentation algorithm.

1788.   A retrospective multi-site, multi-manufacturer comparison of T1-weighted anatomical brain scans using tissue classification
Alain Pitiot1, Olivier Mougin2, Nikos Evangelou3, and Paul S Morgan4
1School of Psychology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Sir Peter Mansfield MR Centre, University of Nottingham, United Kingdom,3Division of Clinical Neurology, University of Nottingham, United Kingdom, 4Medical Physics, University of Nottingham, United Kingdom

Great care is taken during the set-up of multi-site neuroimaging MR studies to ensure that data from different scanners across different sites can be combined appropriately. In practice there is a limit to how similar imaging protocols can be. Here we take a pragmatic, retrospective approach to investigate whether protocol variations results in a measureable effect on the anatomical brain images of a single subject scanned multiple times on MR scanners from 2 manufacturers installed at 3 sites. Very little differences were found, suggesting that standardising multi-site protocols may be less critical when combining data.

1789.   MP3 your A1! How frequent headphone-usage shapes your auditory cortex
Robert Trampel1, Andreas Schäfer1, Christine Lucas Tardif1, Miriam Waehnert1, Marcel Weiss1,2, Juliane Dinse1, Pierre-Louis Bazin1, and Robert Turner1
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Faculty of Social and Behavioral Sciences, University of Amsterdam, Amsterdam, Netherlands

Due to the increasing popularity of devices such as mobile phones and MP3 players, more and more people frequently use headphones. We considered whether such intense headphone usage affects the myelination of primary human auditory cortex A1. Using maps of longitudinal relaxation time T1 as a marker for cortical myelin content, we show that in A1 weekly headphone usage rate is negatively correlated with T1. This finding suggests that frequent exposure to loud auditory stimuli increases myelination in primary auditory cortex.

1790.   The MRI of Darwin: The Brain Catalogue
Mathieu David Santin1, Marc Herbin2, Florencia Grisanti2, and Roberto Toro3,4
1CENIR, ICM, Paris, France, 2UMR 7179, Museum National d'Histoire Naturelle, Paris, France, 3Human Genetics and Cognitive Functions, Institut Pasteur, Paris, France,4CNRS URA 2182, Genes, synapses and cognition, Paris, France

Create open-access library of more than 1800 brain MRI datasets. Study the phylogeny of the vertebrate brain.

1791.   Simple, Accurate, Whole-Brain White Matter Segmentation in 3 Seconds
Wenzhe Xue1,2, Christine M. Zwart2, and Joseph Ross Mitchell2
1Biomedical Informatics, Arizona State University, Scottsdale, AZ, United States, 2Radiology, Mayo Clinic, Scottsdale, AZ, United States

Segmentation of brain white matter could aid assessment of neurological disorders. However, this is not routinely performed in clinical settings, due in part to long computation times and the need for users to carefully tune multiple algorithm parameters to achieve acceptable results. Our goal is to develop a simple, rapid, reliable and accurate technique to segment brain white matter, gray matter and ventricles. We are extending the new parallel level set algorithm proposed by Roberts et. al.. This algorithm efficiently leverages the massive parallelism of commodity graphical processing units (GPUs) to achieve a 14x speed over previous parallel algorithms. Despite this speed advantage, the user is still required to place an initial seed and then tune three parameters to achieve acceptable results. The tuning process requires expertise and increases segmentation time, variability, and inconvenience. Here we report on efforts to automatically select optimal values for the three algorithm parameters when segmenting brain white matter in T1-weighted MR exams.

1792.   Pediatric ALL: Characterization of WM Damage and Associated Risk Factors
Jennifer R. Pryweller1, John O. Glass1, Xingyu Li2, Yimei Li2, and Wilburn E. Reddick1
1Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, United States, 2Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, United States

MR neuroimaging studies of pediatric acute lymphoblastic leukemia (ALL), the most common form of pediatric cancer, reveal leukoencenphalopathy (LE), the most common neurotoxic side effect of treatment with high dose methotrexate. Because neurocognitive deficits resulting from LE in pediatric ALL patients can have devastating effects on quality of life, long term, the purpose of our study was to objectively assess influence and risk factors for LE in these, which was characterized by T1 and T2 intensity and relaxation rates, and the volumetric extent of abnormal white matter.

1793.   Inverse Relationship of Internal Jugular Vein Narrowing and Increased Brain Volumes is Mitigated by Age in Healthy Individuals
Chris Magnano1,2, Pavel Belov1, Jacqueline Krawiecki1, Steven Grisafi1, Jesper Hagemeier1, and Robert Zivadinov1,2
1BNAC, SUNY Buffalo, Buffalo, NY, United States, 2MRI, Clinical & Translational Research Center, Buffalo, NY, United States

In 135 healthy controls, internal jugular vein (IJV) narrowing was found to significantly correlate with increased brain volumes, when accounting for sex and cardiovascular risk factors. This finding could be potentially indicative of edema, venous stasis, or swelling of the brain parenchyma. This relationship was lost when accounting for age. More robust correlations were found at lower cervical levels (C7/T1) than higher levels (C2/C3). This is the first study investigating the relationship between IJV narrowing and brain volumes in healthy individuals.

1794.   A comparative study of two partial volume estimation methods with MP2RAGE data at 3T
Quentin Duché1,2, Parnesh Raniga2,3, Gary F. Egan3, Oscar Acosta1, Olivier Salvado2, Giulio Gambarota1, and Hervé Saint-Jalmes1
1Université de Rennes 1 - LTSI, Rennes, France, 2The Australian e-Health Research Centre, CSIRO Preventative Health Flagship, CSIRO Computational Informatics, Herston, QLD, Australia, 3Monash Biomedical Imaging, Melbourne, VIC, Australia

Partial volume (PV) effects are an unavoidable artifact in brain MRI. It may critically influence structural measurements (volumes, cortical thickness) if not taken into account. This study aims at comparing the plebiscited PV estimation technique and the proposed method on four MP2RAGE datasets. The experimental results match with the simulations and show that the plebiscited method tends to understimate GM in both types of mixtures (GM/CSF and GM/WM). This implies a global GM volume underestimation of 3.43% in average.

1795.   Validation of Cortical Thickness/Volume Data from Multi-Echo MPRAGE Scans with Variable Acceleration in Young and Elderly Populations
Ross W. Mair1,2, Martin Reuter2,3, and Andre J. van der Kouwe2
1Center for Brain Science, Harvard University, Cambridge, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States, 3Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States

The multi-echo MPRAGE (MEMPRAGE) sequence was implemented to reduce signal distortion by acquiring at a higher bandwidth and averaging multiple echoes to recover SNR while providing additional T2* information that can enhance cortical segmentation. Here, we compare morphometric results for cortical thickness/gray matter volume obtained from a rapid 2-minute MEMPRAGE scan with four-fold acceleration by comparison to those from a 6-minute, 1 mm isotropic, two-fold accelerated MEMPRAGE scan acquired in the same session. The results show a small but usually significant bias to the p2 scan, but correlations remain high. Good correlation is also obtained for morphometric data between scans on elderly subjects, albeit with slightly lower correlation than for healthy young adults.

1796.   Super-resolution multi-fascicle imaging reveals the presence of both radial and tangential diffusion in the mature cortex using a clinical scanner.
Benoit Scherrer1, Ali Gholipour1, Mustafa Sahin2, Sanjay P Prabhu1, and Simon K. Warfield1
1Radiology, Harvard Medical School, Boston Children's Hospital, Boston, MA, United States, 2Neurology, Harvard Medical School, Boston Children's Hospital, Boston, MA, United States

We demonstrate that when employing a multi-fascicle model at each voxel and quantitative super-resolution diffusion imaging, the presence of both radial and tangential diffusion can be observed in each grey matter voxel with a clinical scanner.

1797.   Subdivision of the occipital lobes with tractography
Michel Thiebaut de Schotten1,2, Marika Urbanski1, Romain Valabregue1, Dimitri Bayle1, and Emmanuelle Volle1
1Brain and Spine Institute, Paris, France, 2Natbrainlab - Institute of Psychiatry, London, United Kingdom

Exploring brain connectivity is fundamental to understanding the functional architecture of the cortex. In our study we employed tractography, combined with the principal component analysis statistical framework, to divide the occipital lobes into eight areas showing sharp differences in their anatomical connectivity in a group of eighteen healthy participants. Our results showed similarities with functional imaging data in healthy controls and cognitive profiles in brain-damaged patients. Taken together these results provide a new promising anatomical subdivision of the living human brain based on its anatomical connectivity,which may benefit neuroanatomical dissociations and functional neuroimaging results.

1798.   Reconstruction of 3D T2-weighted brain volumes from 2D high-resolution sequences
Andrea Nordio1, Denis Peruzzo1,2, Fabio Triulzi1,3, and Filippo Arrigoni1
1Neuroimaging, Scientific Institute, IRCCS E.Medea, Bosisio Parini, Lecco, Italy, 2Computer Science, University of Verona, Verona, Italy, 3Neuroimaging, Fondazione IRCCS Ca' Granda, Ospedale Maggiore, Policlinico, Milano, Italy

In clinical practice, 2D T2-weighted images are usually acquired with an high in-plane resolution, but with really depth thickness to avoid low signal-to-noise ratio (SNR) and too long acquisition times. A quantitative analysis of cortical structures has never been performed because of resolution’s constraints. Our purpose in this project was to build a 3D T2-weighted isotropic volume from a series of high-resolution 2D T2-weighted images using a Super-Resolution algorithm. The results allowed us to detect small structures, such as cortical layers on multiplanar reconstructed planes, confirming the robustness off the method and allowing future quantitative measurements.

1799.   Development of a Clinical Protocol for Magnetic Resonance Elastography of Brain
Andrea Steuwe1, Marius Mada1, and Adrian Carpenter1
1University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

Manual palpation plays an important role in the clinician's routine. This is unfeasible when the tissue of interest is inaccessible, such as the brain inside the skull. Magnetic resonance elastography (MRE) has the potential to replace palpation, by objectively assessing the mechanical properties of tissue. However, for the implementation of this technique in clinical practice there is an abundance of issues that need to be addressed. The aim of this study is the development of a clinical protocol suitable for the human brain, looking at the choice of actuator, MR sequence, wave frequency and RF coil.

1800.   An Average Image of Myeloarchitecture in Common Marmoset Monkeys (Callithrix jacchus)
Nicholas A Bock1, Cecil C Yen2, Lianne Lobo1, Stefan Geyer3, Robert Turner3, and Afonso C Silva2
1McMaster University, Hamilton, Ontario, Canada, 2National Institute of Stroke/ National Institutes of Health, Bethesda, Maryland, United States, 3Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

Myeloarchitecture in the marmoset can accurately define many cortical regions, and would make a good basis for a digital atlas of the marmoset cortex. The imaging demands are stringent however, and a high resolution and contrast-to-noise are needed to resolve fine details in the myeloarchitecture. Here we present an average in vivoimage based on four marmosets that better visualizes myeloarchitecture than images of individual monkeys. We plan to increase the number of monkeys comprising this average image and use it to create a digital atlas of myeloarchitecture in the marmoset.

1801.   Evidence of non-normal distributions in brain imaging data from normal subjects: implications for diagnosis of disease
David Alexander Dickie1, Dominic E Job1, Joanna M Wardlaw1, David H Laidlaw2, and Mark E Bastin1
1The University of Edinburgh, Edinburgh, United Kingdom, 2Brown University, Providence, RI, United States

The most commonly used statistical methods in brain imaging are parametric, i.e., assume data follow the normal (Gaussian) distribution. Whether or not structural brain MRI data follow the Gaussian distribution, and whether this actually matters, has yet to be determined. This work tested whether brain MRI volumes in a typically sized adult sample (n=80; 25-64 years) were Gaussian distributed. The impact of distribution shape on effect sizes between age groups was then determined. We found that these data were not Gaussian. This led to large, unsystematic errors in parametric effect sizes of normal ageing brain volumes.

1802.   A PDE approach for automatic thickness estimation using partial volume classification
Easswar Balasubramaniam1, Anand Joshi1, David Shattuck2, and Richard Leahy1
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 2Neurology, University of California, Los Angeles, CA, United States

We present a new method for estimating the cortical thickness of the human brain from MR images. Our approach uses an anisotropic heat equation that takes into account the partial volume classification of GM, WM and CSF tissue types. We compare our method with conventional methods that use linked distance and the heat equation.

1803.   Evaluating structural brain networks based on their performance in predicting functional connectivity
Fani Deligianni1, Chris A. Clark1, and Jonathan D. Clayden1
1Institute of Child Health, UCL, London, United Kingdom

Structural networks are described as graphs, which only summarize microstructural properties recovered via tractography. The edges of a brain graph may reflect the number of streamlines connecting each pair of regions or the average fractional anisotropy or average mean diffusivity and so on. Understanding the implication of these network properties is not straightforward. Here, we hypothesize that a more accurate reconstructed structural network would be able to predict functional connectivity better. We evaluate how well structural brain networks predict functional connectivity based on sparse canonical correlation analysis.

1804.   Constructing structural connectivity in rat brain based on inter-regional gray matter volume covariations
Ziyu Cao1, Liqin Yang1, Xuxia Wang1, Fuchun Lin1, and Hao Lei1
1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, China

We constructed the anatomical network of rat brain based on gray matter volume covariations. The small-worldness was detected, and Newman's modularity mothed was performed to divide the network into five communities. This work may contribute to the future study of rat brain structure.

1805.   Quantification Myelin Mapping Through Short T1 Component Filtering Linear Combination Using Multi Flip Angle SPGR Data
Zhe Wu1, Minming Zhang2, Yong Zhang3, and Yiping Du1
1Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang, China, 2Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China, 3MR Research, GE Healthcare, Shanghai, China

This preliminary study demonstrates the feasibility of myelin water fraction (MWF) mapping through short T1 component filtering. The data are collected with multi flip angle SPGR sequence and post-processed by linear combination. This new approach provides a fast acquisition and post-processing alternative for quantitative myelin mapping.


Normal Brain Physiology

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

Metabolite concentration changes in the human auditory cortex using functional Magnetic Resonance Spectroscopy (fMRS) at 7 Tesla
Benoit Schaller1, Lijing Xin2, and Rolf Gruetter1
1Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 2Department of Radiology, University of Lausanne, Lausanne, Vaud, Switzerland

Functional MRS investigates metabolite changes during neuronal activation by continuously acquiring MR spectra during a functional task. Recent fMRS studies performed at 7 T reported similar metabolite changes, in particular a lactate increase around 10-20% during visual and motor activation. Thus, it is of interest to further characterize the relationship between neuronal activation and energy metabolism, in other brain areas, such as the auditory cortex in the human brain investigated here for the first time. Statistically significant increases of Lac by 11±4% (p<0.02, n=7) and of Glu by 2±1% (p<0.007, n=7) were found. We suggest that Glu and Lac changes may be a general manifestation of neuronal activation.

Glutamate Concentration is Directly Correlated with Alpha Power Attenuation from Eyes Closed to Eyes Open in Human Occipital Lobe
Emily Mason1, Swati Rane1, Erin Hussey1, Subechhya Pradhan1, Kevin Waddell1, Manus J Donahue1, and Brandon A Ally1
1Vanderbilt University, Nashville, TN, United States

One classically observed EEG signal is the attenuation in power in the alpha bandwidth (8-12 Hz) that is seen when a subject goes from resting with eyes closed to resting with eyes open. The neurochemical contributions to this phenomenon are not clearly understood, however it is believed that the activation and resultant desynchronization of glutamatergic pyramidal neurons are the underlying cause. In this study, magnetic resonance spectroscopy was used to determine the impact that glutamate concentration in the occipital lobe may have on an individual’s alpha attenuation. As predicted, glutamate concentration and alpha attenuation are significantly and directly related.

1808.   Imaging Vitreous Oxygen Tension with Modified Look-Locker T1 Measurement
Andrew Bresnen1, Eric R. Muir1, Oscar San Emeterio Nateras1, and Timothy Q. Duong1
1UTHSCSA - Research Imaging Institute, San Antonio, Tx, United States

Abnormal vitreal oxygen tension (pO2) has been implicated in a number of ocular and retinal diseases. We previously used MRI to non-invasively map pO2 of the human vitreous. In this study we improved spatiotemporal resolution using a modified Look-Locker sequence and improved surface coil and reported vitreous as well as anterior chamber pO2.

1809.   Blood volume functional MRI of the mouse whole brain
Linlin Cong1, Eric R. Muir1, William E. Rogers1, Bryan H. De La Garza1, KC Biju2, Robert A. Clark3, and Timothy Q. Duong1
1Research Imaging Institute, University Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2Department of Medicine, University Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 3Insititute for integration of Medicine & science and south Texas Veterans Health Care System, San Antonio, Texas, United States

Olfaction is one of the most important sensory systems, particularly for rodents. Investigation of the olfactory network from olfactory bulb to the whole brain opens a unique window for us to better understand numerous brain functions. To our knowledge, no previous studies on the whole brain circuit activation in rodent with odor stimulation have been reported. A novel method is necessary for investigation of the pathway of olfactory function. In this study, fMRI responses of the mouse whole brain to odor stimulation was achieved by using blood-volume weighted magnetic iron oxide nanoparticles (MION) to achieve high fMRI sensitivity.

1810.   Late-onset depression and the BDNF Val66Met polymorphism influence the functional connectivity of hippocampus: a resting-state functional MRI study
Yingying Yin1, Yonggui Yuan2,3, and Zhenghua Hou4
1School of Southeast University, Nanjing, Jiangsu, China, 2School of Southeast University, Jiangsu, China, 3Affiliated ZhongDa Hospital of Southeast University, Jiangsu, China, 4The 4th People¡¯s Hospital of Wuhu City, Anhui, China

The abstract summarized the objective, method,results and conclusion of our work.There is a figure displayed the results.

1811.   Inhibitory Functioning in Fear Extinction: GABA and BOLD Responses
Nina Levar1,2, Nicolaas A. J. Puts3,4, Judith van Leeuwen1,2, Damiaan Denys1, and Guido A. van Wingen1,2
1Department of Psychiatry, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands, 2Brain Imaging Center, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands, 3Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore, Maryland, United States, 4FM Kirby Center for Functional Brain Imaging, Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, Maryland, United States

The GABAergic system is thought to play a key role in the regulation of fear and its dysregulation may contribute to the development of pathological anxiety. We performed a multimodal imaging study combining gamma-aminobutyric acid (GABA) magnetic resonance spectroscopy (MRS) with functional MRI in order to investigate the impact of individuals differences in dorsal anterior cingulate cortex (dACC) GABA concentrations on BOLD activity during extinction learning. A correlation analysis showed that healthy participants with low dACC GABA levels displayed reduced extinction learning to an aversive stimulus at trend level.

1812.   In vivo cerebral perfusion territory and watershed zone delineation in healthy volunteers using ASL, DSC-, and DCE-MRI.
Gerard Thompson1 and Alan Jackson1
1University of Manchester, Manchester, United Kingdom

We used timing parameters from a variety of perfusion-based MR imaging techniques (ASL, DSC-, and DCE-MRI) in order to investigate the major hemispheric, subcortical, and cerebellar perfusion territories and intervening watershed zones in a group of healthy volunteers with non-variant circle of Willis anatomy. An MNI space atlas was then constructed delineating a probabilistic map of these perfusion territories, the first time such a map has been produced from in vivo data. Such information is invaluable to those investigating links between neurovascular hemodynamics and other neurological conditions.

1813.   Automatic resting-state fMRI Independent Component Classification using Support Vector Machines
Yanlu Wang1,2 and Tie-Qiang Li1,2
1Clinical Science, Intervention, and Technology, Karolinska Institute, Stockholm, Stockholm, Sweden, 2Medical Physics, Karolinska University Hospital, Huddinge, Stockholm, Sweden

To facilitate the identification of meaningful components from ICA analysis for resting-state fMRI data, we have developed a supervised classification framework based on support vector machines for automatic identification of noise/artifact components. By using classifiers that reflect typical instructions for visual inspection and are invariant of training dataset, our framework achieved zero false negative rates and consistently low false positive rates for identifying noise/artifact components. Our framework facilitates ICA-based analysis of resting-state fMRI data with high model orders, and can be used for automatic removal of noise/artifact components without risking discarding any potentially interesting and meaningful components.

1814.   4D Flow MRI to quantify cerebral blood flow during environmental challenges
J. Mikhail Kellawan1, John W Harrell1, Alejandro Roldan-Alzate2, Cameron Rousseau1, Oliver Wieben2, and William G Schrage1
1Department of Kinesiology, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Departments of Medical Physics and Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

Purpose: To quantify total and regional cerebral blood flow (CBF) in humans to hypoxia and ±cyclooxygenase inhibition (Indomethacin). Methods: After baseline scans (4D flow MRI), subjects breathed 10% oxygen to reduce arterial saturation (~83%). Hypoxia duration was 10 minutes with 4D PC VIPR scan from min 5-10. Results: Segmentation quality of angiograms was excellent. CBF increased with hypoxia; the increase was 3x greater in women. Indomethacin reduced or increased CBF in a sex and artery specific manner. Summary: 4D flow MRI can quantify CBF in the entire cerebrovascular system and with high spatial resolution and physiologic functional data.

1815.   Analysis of Group ICA functional connectivity of task-driven fMRI: application to language processes in adults with auditory deprivation
Antonio Napolitano1, Martina Andellini1, Vittorio Cannatà1, Francesco Randisi2, Bruno Bernardi2, Marianna Castrataro3, Giovanni Pezzullo3, Pasquale Rinaldi3, Maria Cristina Caselli3, and Laura Barca3
1Enterprise Risk Management, Bambino Gesù children's hospital, Rome, Lazio, Italy, 2Unit of Neuroradiology, Bambino Gesù children's hospital, Rome, Lazio, Italy, 3Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Lazio, Italy

Task-driven fMRI has been used to investigate brain networks during a reading process task in deaf signer, deaf using spoken language and control subjects; The study originate from the hypothesis of the existence of a very basic network that plays the role of general framework for language processing. The group specific ICs were identified by ICA and dual regression technique. Interestingly, we found differences in those networks which has been recognized implicated to auditory and to cognition-language processes.

1816.   Functional MRI of the visual pathway in conscious, awake marmosets
Jennifer L Ciuchta1, ChiaChun Hung1,2, Cecil Chern-Chyi Yen1, Daniel Papoti1, David A Leopold2, and Afonso C Silva1
1CMU/LFMI/NINDS, National Institutes of Health, Bethesda, MD, United States, 2SCNI/LN/NIMH, National Institutes of Health, Bethesda, MD, United States

The common marmoset (Callithrix jacchus), a small New World monkey with a highly developed visual cortex, is an emerging model to study primate visual processing. Robust BOLD signals in cortical and subcortical areas are measured while the animals are awake, and actively engaged in the visual stimuli. A custom-printed helmet with embedded surface coils restricted each subject’s head movement totally non-invasively. Higher cortical areas in the ventral stream responded more strongly to structured stimuli compared to scrambled controls. Our results demonstrate the promise of using awake behaving marmosets as a model for studying primate vision using fMRI.

1817.   Differential involvement of cortical and cerebellar areas using dominant and non dominant hands
Adnan Alahmadi1,2, Rebecca Samson1, David Gasston3, Egidio D'Angelo4,5, Ahmed Toosy1,6, and Claudia A.M. Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom, 2Department of Diagnostic Radiology, Faculty of Applied Medical Science, KAU, Jeddah, Saudi Arabia, 3Department of Neuroimaging, Institute of Psychiatry, King's College London, London, United Kingdom, 4Department of Brain and Behavioral Sciences, Neurophysiology Unit, University of Pavia, Pavia, Italy, 5Brain Connectivity Center, IRCCS C.Mondino, Pavia, Italy,6NMR Research Unit, Department of Brain Repair and Rehabilitation, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom

We investigated common and specific brain activations in contra and ipsi-lateral (CL and IL) hemispheres using a complex motor fMRI task with variable grip force performed with dominant and non-dominant hands (DH and NDH) in right handed healthy subjects. We showed there are: 1) increased activations in more areas at the highest force when performing the task using the NDH. 2) More activations in the right hemisphere irrespective of the hand or force level. 3) Common areas in CL and IL hemispheres at specific force levels such as SMA. 4) Consistent bilateral cerebellum involvement when performing the task using NDH

1818.   Characterizing temporal variations of functional connectivity in resting-state
Zening Fu1, Xin Di2, Shing Chow Chan1, Yeung Sam Hung1, Bharat B. Biswal2, and Zhiguo Zhang1
1Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong, China, 2Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, United States

The temporal variation in functional connectivity (FC) may convey important information about the integration and coordination of human brain. Recently, sliding-window analysis is a dominant approach to characterize temporal dynamics of FC, but there is still lacking an effective method to select the window size adaptively to cater for FC dynamics with different degrees of non-stationarity. In this work, we introduce a data-driven variable window selection method for estimating the time-varying correlation coefficient and apply it to investigate temporal variability of FC in resting-state fMRI. The results demonstrate that between-network FC exhibits a significantly larger temporal variation than within-network FC.

1819.   High Resolution Mapping of Intravascular Water Molecule Lifetime in the Rhesus Macaque Brain
Ian J Tagge1,2, Xin Li1, Steven G. Kohama3, Christopher D Kroenke1,4, Yosef A Berlow1, Vincent B Warren4, Theodore R Hobbs4, Scott A Horrocks4, Nancy L Cady4, Jonathan Q Purnell5, Charles S Springer, Jr.1, and William D Rooney1
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon, United States, 2Biomedical Engineering, Oregon Health & Science University, Portland, Oregon, United States, 3Oregon National Primate Research Center, Hillsboro, Oregon, United States, 4Oregon National Primate Research Center, Oregon, United States, 5Department of Endocrinology, Oregon Health & Science University, Oregon, United States

Feasibility of measuring physiologically important parameters such as blood volume fraction (vb) and mean intravascular water molecule lifetime (lower case Greek taub) with pharmacokinetic modeling of 3D GRE DCE-MRI data is investigated. Parametric maps are presented for healthy adult Rhesus Macaque brain tissue. High parameter precision (evaluated by Monte Carlo simulation) is achieved in all tissues and parameters evaluated. 3D GRE acquisition offers advantages over common qT1 techniques including faster acquisition time and greater tissue coverage. These parameters are potentially powerful biomarkers in the study of neurovascular diseases and therapies.

1820.   Improved GABA editing at 3T with real-time motion correction, shim update and reacquisition of MEGA-LASER
Ovidiu Cristian Andronesi1, Wolfgang Bogner2, Aaron Hess3, Dylan M. Tisdall1, Paul Wighton1, Himanshu Bhat4, Dinesh Deelchand5, Malgorzata Marjanska5, Andre van der Kouwe1, and Bruce R. Rosen1
1Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 2MR Center of Excellence, Department of Radiology, Medical University Vienna, Vienna, Vienna, Austria, 3Centre for Clinical Magnetic Resonance, John Radcliffe Hospital, University of Oxford, Oxford, Oxford, United Kingdom, 4Siemens Healthcare USA, Boston, MA, United States, 5Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

The mechanisms by which GABA modulates brain activity have become a major topic in neuroscience and neuropsychiatric research. MR spectroscopy (MRS) provides the only non-invasive way to measure GABA levels in-vivo, but its low levels and spectral overlap with abundant brain metabolites make this task challenging. In particular, J-difference MRS provides the highest retained signal for in-vivo GABA editing. However, difference methods are susceptible to subtraction artifacts caused by subject movement and scanner drifts. Low concentration of GABA requires long measurement times, and makes its editing especially prone to this types of artifacts. Here, we show that real-time motion correction combined with dynamic shim update and reacquisition can eliminate artifacts and preserve the GABA signal. In particular, the addition of reacquisition into the correction algorithm is newly demonstrated here for GABA editing with an optimized adiabatic MEGA-LASER sequence.

1821.   Differences in Cerebrovascular Reactivity in Posterior Circulation Territories obtained with BOLD and ASL MRI using Hypercapnic Challenges
Jeroen C.W. Siero1, Alex Bhogal1, Carlos Faraco2, Jeroen Hendrikse1, and Manus J. Donahue2
1University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Radiology and Radiological Sciences, Vanderbilt University, TN, United States

We performed cerebrovascular reactivity measurements in healthy subjects using BOLD and CBF for different hypercapnic and hyperoxic conditions, focussing on posterior circulation territories. Results demonstrate that CVR in posterior circulation territories is regionally dependent, at least for CBF. Observed differences between CBF and BOLD based CVR may indicate differences in vascular and metabolic condition. Future work will aim at elucidating and separating these effects by comparing healthy subjects and patients with posterior circulation pathology.

1822.   Investigating BOLD signal properties under targeted hyperoxic combined with progressive hypercapnia at 7T
Alex Bhogal1, Esben Petersen1, Manus J Donahue2, Marielle Philippens3, Peter Luijten1, Hans Hoogduin1, and Jeroen C.W. Siero1
1Radiology, University Medical Center, Utrecht, Netherlands, 2Radiology and Radiological Sciences, Vanderbilt University, TN, United States, 3Radiotherapy, University Medical Center, Utrecht, Netherlands

Using high spatio and temporal resolution BOLD imaging at 7T in combination with a prospective end-tidal gas targeting system (RespirAct), we examine the non-linearity of the BOLD-CVR response to increasing PaCO2 under targeted normoxia and hyperoxia in order to shed light on vascular (maximum vasodilation) and susceptibility dependent (BOLD ceiling) BOLD signal components.

1823.   Sustained hypoxia attenuates CBF and BOLD activation in visual cortex
Zachary M Smith1 and David J Dubowitz1
1University of California, La Jolla, CA, United States

To assess how hypoxia impacts neurovascular coupling, we examined the CBF/BOLD responses to visual activation following 2-days sustained hypoxia. Following hypoxia, the fractional change in response to the stimulus in both BOLD and CBF decreased by 50%. The reduced BOLD response can be explained by the reduction of the fractional CBF response alone, suggesting that other influences (baseline deoxyhemoglobin, coupling of the flow and metabolism responses, or cerebral blood volume responses) are essentially self-canceling. The absolute CBF during the stimulus was similar in both normoxia and hypoxia. The reduced fractional CBF response was due to increased baseline CBF during hypoxia.

1824.   Discrepant Resting-state Brain Activity in Geriatric Depression and Depressed Parkinson¡¯s disease: A Resting-State fMRI Study
Yingying Yin1, Yonggui Yuan2, Zhenghua Hou3, and Weiguo Liu4
1Neuropsychiatry, School of Southeast University, Nanjing, Jiangsu, China, 2Affiliated ZhongDa Hospital of Southeast University, and Institute of Neuropsychiatry of Southeast U, Jiangsu, China, 3The 4th People¡¯s Hospital of Wuhu City, Anhui, China, 4Nanjing Brain Hospital affiliated to Nanjing Medical University, Jiangsu, China

The abstract summarized our work of the discrepant Resting-state Brain Activity in Geriatric Depression and Depressed Parkinson¡¯s Disease using resting-state fMRI technique.There are a totle of 5 parts in the abstract,they are purpose,methods,resules,conclusions and references. There are two figures displaying the resultes.

1825.   Mapping the dynamic relationship between cerebral blood flow and BOLD fluctuations: Implications for quantitative fMRI
Aaron Benjamin Simon1 and Richard Buxton2
1Bioengineering, University of California San Diego, La Jolla, CA, United States, 2Radiology, University of California San Diego, La Jolla, CA, United States

In this work we measured the blood flow and BOLD responses to visual stimuli, the strength of which were varied sinusoidally at several temporal frequencies. Our goal was to determine whether the function that mapped flow to BOLD responses was unique, or whether it depended on the frequency or phase of the stimulus. We found that the mapping from flow to BOLD had little dependence on the stimulus frequency or phase but that the mapping function was not unique between stimulus on and off periods, suggesting that slow changes in volume or metabolism may complicate the dynamic flow-BOLD relationship.

1826.   The influence of carbon dioxide on brain functional homotopy using resting-state fMRI
Olga Marshall1, Jinsoo Uh2, Daniel Lurie3, Hanzhang Lu2, Michael P. Milham3,4, and Yulin Ge1
11Radiology/Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 22Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Texas, United States, 3Child Mind Institute, New York, United States, 4Nathan S Kline Institute for Psychiatric Research, New York, United States

Resting state functional MRI (RS-fMRI) using blood oxygenation level dependent (BOLD) technique is used to evaluate the functional connectivity of the human brain. Brain homotopy (inter-hemispheric coordination) is a fundamental characteristic of the intrinsic functional architecture, which now can be assessed with RS-fMRI. Regional homogeneity (Reho) is another brain characteristic and RS-fMRI measure for local brain synchronization. In this study, we have evaluated how CO2 breathing can influence brain functional homotopy and Reho in healthy brains at rest in order to better understand the physiologic respiratory challenge on global inter-hemispheric and local neighboring neurons functional correlations.

1827.   BOLD Evoked Response during Hyperbaric conditions
Damon P Cardenas1,2, Eric Muir1,2, Shiliang huang2, and Timothy Duong1,2
1Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2MRI, Research Imaging Institute, San Antonio, Texas, United States

There are substantial interests in the effects of basal oxygen saturation on BOLD fMRI responses. We evaluated forepaw-evoked BOLD responses in rats under i) normobaric air, ii) normobaric oxygen, iii) 3 atmospheres hyperbaric air, and iv) 3 atmospheres hyperbaric oxygen (HBO). Robust and strong BOLD responses were detected under HBO similar to normobaric air condition, suggesting that there is room to increase total hemoglobin saturation or that other signal mechnisms are involved during HBO.

1828.   Parenchyma Spin Labeling of Cerebral Intracranial Venous using Time-SLIP
yuichi yamashita1, Hisae Chiba1, Shin Takamatsu1, Akari Yamada1, Hiroyuki Miyazaki2, Yoshihito Miyamoto2, Satoshi Uchinomura2, and Tsutomu Katoh2
1TOSHIBA MEDICAL SYSTEMS CORPORATION, Ootawara, Tochigi, Japan, 2Sumitomo Besshi Hospital, Ehime, Japan

The Time-Spatial Labeling Inversion Pulse (Time-SLIP) method allows blood vessels to be visualized without the use of contrast medium. In the present study, it was confirmed that various target vessels can be selectively visualized by adjusting the Time-SLIP pulse application position. Furthermore, the Hemodynamics of Intracranial Venous Flow can also be visualized without the use of contrast medium. Therefore, the results of this study suggest that the Hemodynamics Intracranial Venous Flow can be visualized safely using the Time-SLIP Technique.

1829.   Blood Volume Flow Rates of Vessels in Healthy Human Cerebral Vasculature
M. Ethan MacDonald1,2, Parviz Dolati2,3, John H. Wong2,4, and Richard Frayne2,4
1Biomedical Engineering, University of Calgary, Caglary, AB, Canada, 2Seaman Family Magnetic Resonance Research Centre, Hotchkiss Brain Institute, Foothills Medical Centre, Calgary, AB, Canada, 3Neurosurgery, Harvard Medical School, Cambridge, MA, United States, 4Radiology & Clinical Neurosciences, University of Calgary, Calgary, AB, Canada

In this work we describe scan twelve healthy human volunteers with phase contrast MRI. Cut planes were placed in twenty-six of the key cerebrovascular segments, and the surface integral of the flow velocity was calculated to yield the volume flow rate in ml per second. We found deviations in the volume flow rates on the order of 20-30% in larger vessels such as the carotid artery and found deviations on the order of 30-40% in smaller vessels such as the middle cerebral arteries.

1830.   Hypercapnia effects on spontaneous low frequency fluctuations using RS-fMRI
Olga Marshall1, Jinsoo Uh2, Daniel Lurie3, Hanzhang Lu2, Michael P. Milham4, and Yulin Ge1
11Radiology/Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 22Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Texas, United States, 3Child Mind Institute, New York, United States, 4Nathan S Kline Institute for Psychiatric Research, New York, United States

Carbon dioxide (CO2) is a potent vasodilator, its effect on brain cerebral blood flow and blood oxygenation level dependent (BOLD) signal changes has been well-studied. However, the influence on resting-state fMRI data is still largely unknown. In this study, we presented the results of both connectivity and amplitude changes of default mode network (DMN) under hypercapnia (mixed 5% CO2, 21% O2, and 74% N2) versus normocapnia condition at rest in healthy brains. We demonstrated that although the intrinsic correlation of the DMN at rest during CO2 remains, there is significantly reduced amplitude (measured with fractional low frequency fluctuations or fALFF) within DMN connectivity under hypercapnia.

1831.   Neuronal current MRI: the effect of neuronal oscillations
Jiaxin Du1, Viktor Vegh1, and David C Reutens1
1Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia

Neuronal current magnetic resonance imaging (nc-MRI) aims to detect neuronal currents using MRI and may provide higher resolution neuronal activity images than existing functional MRI methods. However, nc-MRI is yet to be convincingly demonstrated. This study investigates the feasibility of nc-MRI using computer simulations. We found that neuronal current induced MRI signal magnitude changes are below currently detectable levels, but that signal phase changes are likely to be detectable using current MRI techniques. We also found that signal phase does not accumulate over time but oscillates with neuronal activity. Therefore, MRI scans need to be synchronized with neuronal oscillation to maximize the chance of detecting signal phase changes due to neuronal currents.

1832.   Changes of brain activities and metabolites in the right dorsolateral prefrontal cortex in patients with obsessive compulsive disorder
Shin-Eui Park1 and Gwang-Woo Jeong1,2
1Chonnam National University, Interdisciplinary Program of Biomedical Engineering, Gwangju, Chonnam, Korea, 2Chonnam National University Hospital, Chonnam National University, Department of Radiology, Medical School, Gwangju, Korea

The obsessive compulsive symptoms are mainly related to the dysfunctional cortico-striatal-thalamic circuit (CSTC), a network involving the prefrontal cortex, striatum, thalamus in pathogenesis. Several neuroimaging or spectroscopy studies revealed differential brain activation patterns during performing memory tasks and metabolic concentration changes in the CSTC circuits. However, the findings from the studies mentioned above have not been consistent. We performed 1H MRS and fMRI study during the implicit memory tasks for the quantification of the brain metabolites and identification of the brain activation patterns in OCD patients.

1833.   Mapping of Relative Vessel Sizes in fMRI With SAGE
Allen T Newton1,2, Jack T Skinner1,2, and C Chad Quarles1,3
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States,3Institute of Imaging Sciences, Vanderbilt University, Nashville, TN, United States

While spin echo measurements have been long established as being more sensitive to activity in capillary beds, gradient echo acquisitions have remained popular due in large part to their improved sensitivity. Here, we present a method for using simultaneous spin echo and gradient echo acquisitions to gain insight to the size of vessels underlying traditional gradient echo eperiments. This is superior to traditional spin echo studies in that it allows you to maintain the sensitivity associated with gradient echo images while providing a more continuous metric that is sensitive to relative vessel size.

1834.   Cerebrospinal fluid (CSF) outflow tracked with gadolinium-enhanced MRI in cynomolgus monkeys
Kyoung-Min Lee1, Jun-Young Chung2, Sang-Rae Lee3, and Kyu-Tae Chang3
1Neurology, Seoul National University Hospital, Seoul, Seoul, Korea, 2Biomedical Engineering, Gachon University, Incheon, Korea, 3National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Ochang, Korea

The pathways and kinetics of cerebrospinal fluid system is imaged using a series of MRI with gadolinium contrast injected via the cistern near foramen magnum of cynomolgus monkeys. The serial images revealed rapid spreading of the contrast agent around the CSF space, followed by slow inflitration to lymphatic system of the neck.

1835.   Improvements to Time-SLIP Imaging of CSF Flow
Matthew Borzage1,2, John Grimm3, Tom Perkins4, Jon Chia4, Gordon McComb5, and Stefan Blüml3,6
1Children's Hospital Los Angeles, Los Angeles, CA, United States, 2Rudi Schulte Research Institute, Santa Barbara, CA, United States, 3Radiology, Children's Hospital Los Angeles, CA, United States, 4Philips Healthcare, OH, United States, 5Children's Hospital Los Angeles, CA, United States, 6Rudi Schulte Research Institute, CA, United States

The time–SLIP modality has potential to assist the management of hydrocephalus and related disorders. However, in practice, the variable delay times between tagging and readout result in different levels of background suppression and renders the clinical interpretation sometimes difficult. We tested a new approach, where background signal is constant and flow is visualized with the MR readout occurring at different cardiac cycle time points. Preliminary studies of 17 patients including cases with no CSF flow, or restored CSF flow resulted in imaging results as expected, and a positive change of patient management.

1836.   Multimodal MRI and NIRS Measurement of CMRO2 in Grey Matter
Runze Yang1, R. Marc Lebel1,2, Qiong Zhang1, Filomeno Cortese3, Ying Wu1, and Jeff F. Dunn1,4
1Radiology, University of Calgary, Calgary, Alberta, Canada, 2GE Healthcare, Calgary, Alberta, Canada, 3Seaman Family MR Research Center, University of Calgary, Calgary, Alberta, Canada, 4Experimental Imaging Center, University of Calgary, Calgary, Alberta, Canada

Abnormalities in cerebral metabolic rate for oxygen (CMRO2) are present in many neurological conditions. The current gold standard for calculating CMRO2 is with PET although MR methods are being introduced. We developed a method of quantifying CMRO2 by combining near-infrared spectroscopy and MRI. In animal experiments, we detected a change in CMRO2 induced by hypothermia. We translated this approach into human studies, where we obtained CMRO2 values similar to those of PET studies. For partial volume reasons, measuring differences between populations or over time in the same subject may be more accurate than measuring absolute values. This could be a useful method for those interested in studying brain oxidative metabolism using MRI.

1837.   Altered functional connectivity of rhesus brain during increasing levels of sevoflurane: a resting-state fMRI study on 3T
Yuan Xiao1, Peilin Lv2, Su Lui1, Min Wu1, Yuqing Wang3, Bin Liu2, and Qiyong Gong1
1Radiology, Huaxi MR Research Center, Chengdu, Sichuan, China, 2Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China, 3Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China

In spite of many years¡¯ research, the exact mechanism of how anesthetics modulate the cerebral function is still unknown. One possible mechanism is that anesthetics could influence the synchrony of neuronal networks as reflected by studies on rats, though the results were controversial 1, 2. However, it is still unclear whether such effects would be observed in rhesus monkeys which are closer to human than rats. Moreover, most previous animal studies were performed at a single anesthetic dose rather than graded levels of anesthesia; the latter one can potentially reveal the dose-dependent alterations of functional connectivity (FC). Thus, present study aimed to investigate alteration of FC in rhesus monkeys at different concentrations of sevoflurane (1.0, 1.3, 1.6 MAC) using resting-state fMRI.

1838.   Determination of CMRO2 changes During Hyperbaric Exposure
Damon P Cardenas1, Eric Muir1, Shiliang huang2, and Timothy Duong1
1Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2MRI, Research Imaging Institute, San Antonio, Texas, United States

The evaluation of CMRO2 at hyperbaric conditions is pivotal to the understanding of the physiological benefits of hyperbaric treatments. We evaluated forepaw-evoked BOLD and CBF responses simultaneously in rats under i) normobaric air, ii) normobaric oxygen, iii) hyperbaric air, and iv) hyperbaric oxygen (HBO). CMRO2 was determined using the aforementioned parameters. Despite interesting physiological response to CO2 challenges at high pressures, no significant differences were identified across conditions, implying the increased oxygen may be in excess of metabolic demand.


Normal Ageing Brain

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1839.   White matter hyperintensities as a confounder in diffusion tensor imaging analysis of elderly cohorts
Daniel Svärd1, Filip Szczepankiewicz2, Markus Nilsson3, Björn Lampinen2, Jimmy Lätt4, Pia Sundgren1,4, Erik Stomrud5, Lennart Minthon5, Katarina Nägga5, Oskar Hansson5, and Danielle van Westen1,4
1Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden, 2Department of Medical Radiation Physics, Lund University, Lund, Sweden, 3Lund University Bioimaging Center, Lund University, Lund, Sweden, 4Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden, 5Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden

Studies on the effect of white matter hyperintensities (WMH), appearing on T2-weighted images, on diffusion tensor imaging (DTI) parameters are scarce in spite of their abundance in normal aging as well as in neurodegenerative disease. Here we quantify the effect size of WMH graded according to Fazekas on DTI parameters mean diffusivity and fractional anisotropy in a healthy elderly cohort using ROI-based analysis. We show that WMH have effect sizes comparable to that of some neurodegenerative diseases and therefore may be an important factor taken into consideration when designing DTI studies including groups with different WMH load.

1840.   Is the rate of change in fractional anisotropy with age constant within white matter tracts? A study of two segments of the Cingulum bundle
Johanna Mårtensson1, Jimmy Lätt2, Danielle van Westen3, Elna-Marie Larsson1, and Markus Nilsson4
1Radiology, Radiology, Oncology and Radiation Science, Uppsala, Uppsala, Sweden, 2Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Lund, Sweden,3Diagnostic Radiology, Skåne University Hospital, Lund, Lund, Sweden, 4Lund University Bioimaging Center, Lund University, Lund, Lund, Sweden

We divide cingulum into two segments and examine the patterns of age-related WM changes in fractional anisotropy (FA) within the segments. The purpose is to investigate whether an antero-posterior gradient in the rate of ageing is present. DTI-MRI was performed on 80 volunteers and FA within the segments analysed as functions of age. FA in the anterior segment decreased 18% between the age of 30 and 83, while FA in the posterior segment decreased 8.3%. Differences in age-related changes may be partly explained by the retrogenesis hypothesis in case cingulum is composed of separate tracts and agrees with antero-posterior maturation.

1841.   Cortical Phase Shifts in Healthy Aging at 7 Tesla
Mathijs Buijs1, Nhat Trung Doan2, Sanneke van Rooden1, Maarten Versluis1, Julien Milles2, Jeroen van der Grond1, and Mark van Buchem1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Division of Image Processing (LKEB), Leiden University Medical Center, Leiden, Netherlands

In recent years phase imaging has become available as a method of measuring iron in vivo. Scanning at 7 Tesla has increased the usability of phase images for smaller structures. The aim of this study was to investigate the appearance of phase contrast in the cerebral cortex in normal aging. We scanned three different age groups and measured cortical phase values using an in-house developed tool. Our study shows an increase in paramagnetic phase shift with age in the cerebral cortex of healthy subjects at 7T. The most significant increase in phase shift is seen between middle and old age.

1842.   Bilateral functional connectivity for complex finger movements declines as aging: an fMRI and SEM exploration
Sachiko Kiyama1, Mitsunobu Kunimi1, Tetsuya Iidaka2, and Toshiharu Nakai1
1National Center for Geriatrics and Gerontology, Ohbu, Japan, 2Nagoya University, Nagoya, Japan

The present study attempted to seek age related declines of functional connectivity within the motor cortices, with particular focus on the effect of movement complexity. fMRI and SEM (structural equation modeling) were utilized to compare neural activity between younger and elderly groups during the visually guided bimanual finger movement task with easier symmetrical mode and complex asymmetrical one. Results revealed age-related differences in functional connectivity within bilateral PMd and that between bilateral SPL during the task, suggesting that the elderlyfs inaccuracy of complex finger movements in tune with visual information derives from declines in bilateral connectivity within these regions.


Brain Cancer

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1843.   Location of Brain Tumor Intersecting White Matter Tracts Predicts Survival Prior to Therapy
Nikolai J Mickevicius1, Alexander Carle2, Stephanie Santarriaga3, Trevor Bluemel4, and Peter S LaViolette4
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Biomedical Engineering, Purdue University, Indiana, United States, 3Neuroscience, Medical College of Wisconsin, Wisconsin, United States, 4Radiology, Medical College of Wisconsin, Wisconsin, United States

Brain tumor intersecting white matter tracts in the cortico-spinal tract, corpus callosum, and cerebellum are associated with decreased survival in glioblastoma patients.

1844.   Prediction of progression free survival in high grade gliomas using pre-operative MR
Lawrence Kenning1, Martin Lowry2, Martin Pickles2, Christopher Roland-Hill3, Shailendra Achawal3, Chittoor Rajaraman3, and Lindsay W Turnbull2,3
1Centre for Magnetic Resonance Investigations, University of Hull, Hull, East Riding of Yorkshire, United Kingdom, 2Centre for Magnetic Resonance Investigations, Hull York Medical School at the University of Hull, Hull, East Riding of Yorkshire, United Kingdom, 3Hull and East Yorkshire Hospitals NHS Trust, East Riding of Yorkshire, United Kingdom

We investigated whether MR could predict progression free survival at 6 months in high grade gliomas. DTI, DCE and DSC were acquired from 39 patients. Volumes of interest were contoured before patients were dichotomised using median values for each parameter. Kaplan-Meier survival analysis at 210 days from pre-operative MR was calculated along with log rank tests to test for significance. Individually, ADC, q, λR, Ktrans, Ve, Vb, and K2 were all significant predictors of progression free survival. Pre-operative MR parameters can predict progression free survival at 6 months in high grade gliomas. DTI, DSC and DCE all have added value.

1845.   Comparison of Quantitative Heterogeneity of Brain Tumors from Diffusion MR Versus Histological Tumour Grade: A Preliminary Study
Dr. Venkatraman Bhat1, Lalit Gupta2, and Dr. Sundararaman VK2
1Narayana Hrudayalaya Hospital, Bangalore, Karnataka, India, 2Philips India Limited, Bangalore, Karnataka, India

In this study, heterogeneity of brain tumors from Apparent Diffusion Co-efficient (ADC) maps is compared with histological tumour grade. 1.5T MR data from 10 patients with brain tumour was retrospectively analyzed. Based on modified co-occurrence matrix based method, a “heterogeneity index” was computed, which was then compared with the final histological tumour grade after surgical resection. Heterogeneity index (from ADC maps) could discriminate between grade 4 and lower grade tumours. For lower grade tumours, small sample size precluded comparative analysis between tumour grade and heterogeneity index. Tumour heterogeneity could be a better marker for tumour grade than mean ADC values.

1846.   Classification of tumor components based on DCE and DSC data in patients with glioblastoma
Moran Artzi1,2, Deborah T. Blumenthal3, Felix Bokstein3, Guy Nadav1,4, Gilad Liberman1, Orna Aizenstein1, and Dafna Ben Bashat1,5
1Functional Brain Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 2Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, 3Neuro-Oncology Service, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 4Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel, 5Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel

Classification of tumor area is important for therapy assessment of patients with glioblastoma (GB). In this study tumor area was classified in sixteen scans (11 patients) using k-mean analyses of DSC and DCE data, (1) based on group analysis; (2) on individual patient basis, using cluster's centroid vectors obtained from the group analysis. Three clusters were identified: permeable-tumor, infiltrative-tumor and vasogenic-edema, validated using MRS. A high correlation was obtained between methods. Five patients were scanned longitudinally following bevacizumab. Results suggest a non-enhancing tumor progression pattern following therapy. This demonstrates the potential of this method to be used in clinical settings.

1847.   Logistic regression of multiparametric MR for glioma grading
Lawrence Kenning1, Martin Lowry2, Martin Pickles2, Christopher Roland-Hill3, Shailendra Achawal3, Chittoor Rajaraman3, and Lindsay W Turnbull2,3
1Centre for Magnetic Resonance Investigations, University of Hull, Hull, East Riding of Yorkshire, United Kingdom, 2Centre for Magnetic Resonance Investigations, Hull York Medical School at the University of Hull, Hull, East Riding of Yorkshire, United Kingdom, 3Hull and East Yorkshire Hospitals NHS Trust, East Riding of Yorkshire, United Kingdom

We investigated the role of functional MR parameters to determine glioma grade using logistic regression models. DTI, DCE and DSC were acquired from 55 glioma patients and ADC, FA, q, RA, λL, λR, R1, Ktrans, ve, vb, rCBVGVF, rCBVBOX, and K2 were calculated. Tumour volumes of interest to sample the data were contoured using morphological imaging. Using multi-parametric MR, 82.8% of cases were correctly classified using a two part logistic regression model decision tree. DTI and DCE appeared to be the most useful for determining lesion grade in this cohort of patients.

1848.   Comparison of standardized and normalized rCBV to differentiate astrocytic brain tumors
Mona M Al-Gizawiy1, Melissa A Prah1, Peter S LaViolette1, Wade M Mueller2, and Kathleen M Schmainda1,3
1Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States, 2Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States,3Biophysics, Medical College of Wisconsin, Wisconsin, United States

Perfusion imaging is an invaluable tool for brain tumor characterization. Relative cerebral blood volume (rCBV) maps provide insight into brain tumor vascularization. The purpose of this study was to compare standardized (sRCBV) and normalized (nRCBV) measures in conjunction with intraoperative navigation and tissue diagnosis for astrocytoma grading. Preoperative imaging was co-registered to intraoperative surgical navigation scans, and rCBV values were calculated for each tissue sampling site. sRCBV showed greater potential in differentiating astrocytic tumors than nRCBV. This study highlights the importance of perfusion imaging in brain tumor characterization.

1849.   Quantitative intra-tumoral susceptibility signal in grading brain astrocytomas with susceptibility-weighted imaging
Tzu-Chao Chuang1, Wan-Pin Shui1, Hsiao-Wen Chung2, and Ping-Hong Lai3,4
1Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan, 2Electrical Engineering, National Taiwan University, Taipei, Taiwan, 3Radiology, Kaohsiung Veteran General Hospital, Kaohsiung, Taiwan, 4School of Medicine, National Yang-Ming University, Taipei, Taiwan

Using susceptibility weighted imaging (SWI), a quantitative measurement of volumetric percentage of intra-tumoral susceptibility signal (ITSS) was reported in order to provide useful information in tumor grading of brain astrocytomas at 1.5 T. High-resolution SWI of 43 patients, including 35 high-grade (WHO grade III and IV) and 8 low-grade (all WHO grade II), were analyzed in this study. With the suggested threshold for ITSS evaluation, significance difference between the ITSS percentages of high-grade and low-grade astrocytomas was found (p<0.01) with an area under ROC curve of 0.89, rendering this quantitative index as a helpful classifier on discrimination of tumor grade.

1850.   3D Texture Analysis of Heterogeneous MRI Data for the Characterisation of Childhood Brain Tumours
Ahmed E Fetit1,2, Jan Novak2,3, Daniel Rodriguez4, Dorothee P Auer4,5, Chris A Clark6, Richard G Grundy4,5, Tim Jaspan5, Andrew C Peet2,3, and Theodoros N Arvanitis1,2
1Institute of Digital Healthcare, WMG, University of Warwick, Coventry, United Kingdom, 2Birmingham Children's Hospital, Birmingham, West Midlands, United Kingdom,3University of Birmingham, Birmingham, West Midlands, United Kingdom, 4University of Nottingham, Nottingham, United Kingdom, 5University Hospital Nottingham, Nottingham, United Kingdom, 6University College London, London, United Kingdom

There is an increasing interest in developing quantitative MR image analysis tools that can capture information below human visual perception and hence assist the diagnosis of childhood brain tumours. In this work, we compare the performance of 3D and 2D texture analysis on multi-modal, heterogeneous MR data sets of children diagnosed with Medulloblastoma, Pilocytic Astrocytoma and Ependymoma. Additionally, we address the problem of class imbalance by creating synthetic tumour samples using Synthetic Minority Over-Sampling Technique (SMOTE) through operating in feature space. Our results support the use of texture analysis as an automated, quantitative technique to assist with the diagnosis of paediatric brain tumours.

1851.   Tumor Progression Mapping: An Intuitive Visualization of Glioblastoma Progression in MR Follow-ups
Christian Weber1, Bram Stieltjes2, Joanna Polanska3, Franciszek Binczyck3,4, Rafal Tarnawski4, Barbara Bobek-Billewicz4, Timo Rodi2, Sebasitian Regnery2, and Klaus H. Maier-Hein1,2
1Medical and Biological Informatics, German Cancer Research Center, Heidelberg, Baden Württemberg, Germany, 2Quantitative Image-based Disease Characterization, German Cancer Research Center, Heidelberg, Baden Württemberg, Germany, 3Silesian University of Technology, Gliwice, Poland, 4Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland

Tumor Progression Mapping as Intuitive Visualization of Glioblastoma Progression in MR Follow-ups: Describes the construction of progression maps which provide an intuitive and compact visualization of the complex evolution of glioblastomas over time. This reduces the complexity of 4D data in a way that supports radiologists in their clinical routine of retracing changes in brain tissue over time which are caused by several complex interactions such as treatment, edema and tumor growth. Furthermore, these maps may aid radiologists to recognize subtle growth patterns that can be easily overlooked

1852.   Assessment of Bevacizumab Treatment Response in High Grade Gliomas using Intravoxel Incoherent Motion (IVIM): A Comparison with Multi-Echo DSC-MRI
Jack T Skinner1,2, Paul L Moots3, and C Chad Quarles1,2
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 3Neurology, Vanderbilt University Medical Center, Nashville, TN, United States

Traditional methods for measuring brain tumor perfusion rely on contrast agent injections. Recently, intravoxel incoherent motion (IVIM) MRI, a non-contrast method, demonstrated sensitivity to tumor perfusion. Non-contrast based perfusion biomarkers of treatment response may be valuable, however, the effect of longitudinal treatment on IVIM acquisitions is unknown. IVIM data was collected in high grade glioma patients receiving bevacizumab and compared to DSC-MRI. In responsive patients, the IVIM signal became more monoexponential, with a robust decrease in CBV and CBF. Further investigation of IVIM characteristics, including the number of tumor voxels suitable for analysis, may provide validation for monitoring tumor treatment.

1853.   Radiomics analysis of multi-parametric MRI in human brain tumours
Martin Lowry1, Lawrence Kenning2, and Lindsay W Turnbull1
1Centre for MR Investigations, Hull York Medical School at University of Hull, Hull, East Yorkshire, United Kingdom, 2Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom

Multi-parametric MRI produces large quantities of data in which parameter associations to tissue characteristics may be hidden. We applied the data mining approach of ‘Radiomics’ to investigate the information content of a pre-operative multi-parametric MR study of gliomas. The results demonstrate redundancy of some parameters but also that DCE, DSC, and DTI can provide complimentary parameters. Several distinct parameter profiles were associated with high grade lesions but only one with low grade lesions despite variation in known prognostic genetic markers amongst the tumours. The approach shows potential for identifying important associations that could influence treatment or predict survival.

1854.   Differential diagnosis of brain tumor recurrence and radiation necrosis using MR spectroscopy
Dita Wagnerova1, Alberto Malucelli2, Monika Dezortova1, Filip Jiru1, Antonin Skoch1, Robert Bartos2, Martin Sames2, and Milan Hajek1
1Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2Department of Neurosurgery, JE Purkyne University and Masaryk Hospital, Usti nad Labem, Czech Republic

MR imaging and MR spectroscopy are used for a differential diagnosis (DD) between tumor recurrence and radionecrosis. In case of MR spectroscopy, most of the authors recommend using increased Choline to Creatine ratio (Cho/Cr) as a marker of tumor recurrence. To further explore this issue, we compared several MRS evaluation methods with histopathology. We found statistically different Cho/Cr values between group of tumor recurrence and group of radionecrosis. However, case-by-case specificity was low. As tumor recurrence showed interhemispheral Choline increase > 15% and radionecrosis < 15%, interhemispheral comparison of Choline values in individual subjects was the best method for DD.

1855.   Histogram Analysis of Saturation Time Dependent Amide Proton Transfer MRI in Brain Metastases
Jochen Keupp1, Yuriko Suzuki2, Osamu Togao3, and Takashi Yoshiura3
1Philips Research Europe, Hamburg, Germany, 2Philips Electronics Japan, Tokyo, Japan, 3Department of Clinical Radiology, Kyushu University Hospital, Fukuoka, Japan

In recent years, amide proton transfer (APT) MRI techniques based on endogenous contrast of exchangeable amide protons of intra-cellular proteins and peptides have been developed successfully and applied in initial clinical studies for oncology and neurology applications. For analysis of the obtained APT measures in tumor tissue and contralateral normal appearing white matter (NAWM), ROI averages are typically used. Because the tumor tissue is often very heterogeneous, histogram analyses and multi-compartment fits are applied in this study on human brain metastases (N=5). Different durations of the sensitizing RF saturation pulse were chosen. With increasing duration, multiple compartments are clearly observed while the overall tumor to NAWM contrast is enhancing. Histogram type analysis is strongly recommended for further investigation of APT contrasts in tumor tissue characterization.

Serial and 2 TE-Acquisition 23Na MRI for Assessment of Therapy Response in Pediatric Glioma
Vincent Kyu Lee1, Yongxian Qian1,2, Fernando Boada3, James Mountz1, and Ashok Panigrahy1
1Radiology, University of Pittsburgh, Pittsburgh, Pa, United States, 2Bioengineering, University of Pittsburgh, Pa, United States, 3Radiology, New York University, NY, United States

In this study, we used serial single quantum 23Na imaging at two separate echo times to study pediatric astrocytomas (total n=8 patients) to help distinguish between proliferation and therapy response. The protein bound sodium, predominantly associated with intracellular sodium, was obtained by subtraction of free sodium (long echo) from total sodium (ultrashort echo). Using this serial 2 TE-Acquisition technique, we were able to characterize the differences in relative sodium concentration between tumors progressing and those lesions responding to therapy. This methodology may prove valuable in assessment of molecularly targeted–based innovative treatment for differentiating pseudoprogression or heterogeneous treatment response.

1857.   Non-invasive MR oxygen mapping of primary central nervous system tumors
Marta M Safronova1, Florence Colliez2, Julie Magat2, Bénédicte F Jordan2, Bernard Gallez2, and Thierry Duprez3
1Service de Radiologie, Cliniques universitaires Saint-Luc, Brussels, Belgium, 2Louvain Drug Research Institute, Biomedical Magnetic Resonance Research Group, University of Louvain, Brussels, Belgium, 3Department of Radiology and Medical Imaging, Cliniques universitaires Saint-Luc, Brussels, Belgium

Neuroepithelial tumors are the most frequent primary central nervous system tumors. Non-invasive measurements of tissue oxygen level variations can be obtained using oxygen itself as an endogenous paramagnetic contrast, a method coined ‘Oxygen enhanced MRI’ providing T1 measurements influenced by O2-related relaxation of water protons. Based on higher solubility of oxygen in lipids than in water, a more sensitive method was developed: ‘MOBILE’ (Mapping of Oxygen By Imaging Lipids relaxation Enhancement). The aim of this study was to assess the clinical applicability of MOBILE for mapping oxygenation of primary central nervous system tumors.

1858.   Long Echo MRS thermometry of childhood brain tumours
Ben Babourina-Brooks1, Martin Wilson1, Theo Arvanitis2, Andrew Peet1, and Nigel Davies3
1University of Birmingham, Birmingham, West Midlands, United Kingdom, 2Birmingham Children’s Hospital NHS Foundation Trus, West Midlands, United Kingdom, 3University hospitals Birmingham trust, West Midlands, United Kingdom

MRS thermometry has been used to characterise two different childhood brain tumour types at low echo time. The PRF measure is dependent on temperature, ionic concentration and chemical exchange. These factors are useful for diagnosis and prognosis of tumours, as they relate to the micro-environment of the tumour. In this study we investigate long echo MRS thermometry to improve the understanding these factors on the PRF measure.

1859.   High resolution assessment of viscoelastic properties of intracranial tumors by multifrequency magnetic resonance elastography
Kaspar Josche Streitberger1, Martin Reiß-Zimmermann2, Karl-Titus Hoffmann2, Dominik Fritzsch2, Florian Baptist Freimann3, Felix Arlt4, Jing Guo1, Sebastian Hirsch1, Jürgen Braun5, and Ingolf Sack1
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, 2Department of Neuroradiology, Universitätsklinikum Leipzig, Leipzig, Germany,3Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, 4Department of Neurosurgery, Universitätsklinikum Leipzig, Leipzig, Germany,5Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany

Goal of our study was to evaluate high-resolution 3D multifrequency MRE in patients with newly diagnosed intracranial tumors. We included 26 patients (63±13 yrs., 18 female), the majority of whom had a primary brain tumor, followed by cerebral metastasis and meningioma and in one case an intra-axial abscess. Meningiomas were found to be clearly stiffer and higher viscous than all other lesions. Grade II-III tumors seemed to be stiffer and higher viscous than grade IV tumors and cerebral metastases.

1860.   High Resolution Magnetic Resonance Elastography of Glioblastoma Multiforme
Kaspar Josche Streitberger1,2, Martin Reiß-Zimmermann3, Karl-Titus Hoffmann3, Florian Baptist Freimann4, Felix Arlt5, Jing Guo1, Sebastian Hirsch1, Jürgen Braun6, and Ingolf Sack1
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, 2Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, 3Department of Neuroradiology, Universitätsklinikum Leipzig, Leipzig, Germany, 4Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, 5Department of Neurosurgery, Universitätsklinikum Leipzig, Leipzig, Germany, 6Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany

This study presents first high resolution MRE of intracranial tumors. The reconstructed MRE parameters |G*| and φ correspond to the magnitude and phase of the complex shear modulus G* and therewith provide a measure of the tumor's viscoelastic properties as encountered by surgeons during interventions. The resolution in |G*| and φ maps is superior to previous work enabling us for the first time to analyze the intrinsic viscoelastic heterogeneities of glioblastoma multiforme (GBM). Interestingly, in 4 out of 17 cases GBM was stiffer than healthy tissue while reduction in φ was seen in all tumors suggesting less dissipative GBM properties.

1861.   Validation of oxygenation and perfusion sensitive MRI methods in healthy brain and brain tumor in mice by invasive micro probe measurements.
Jan Sedlacik1, Matthias Reitz2, Nils O Schmidt2, and Jens Fiehler1
1Neuroradiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany, 2Neurosurgery, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany

Non-invasive assessment of (patho-) physiological parameters, such as perfusion, oxygenation and oxygen metabolism is of great importance for the characterization of pathologies, e.g. tumors, which may be helpful to better predict treatment response and potential outcome. MRI methods sensitive to blood oxygenation and perfusion were validated in healthy mice brain and mice with brain tumors by subsequent invasive micro probe measurements during different free breathing conditions (air, air+10% CO2 and 100% O2).


Animal Models Stroke & Blood Brain Barrier

Tuesday 13 May 2014
Traditional Poster Hall  13:30 - 15:30

1862.   Functional and anatomical changes of somatosensory cortex in rats recovering from severe neonatal hypoxic-ischemic encephalopathy (HIE) brain injury
Jae-Hun Kim1, Geun Ho Im2, Won Beom Jung2, Moon-Sun Jang2, Kyoung-Nam Kim2, Julius Juhyun Chung3, Sun Young Chae3, and Jung Hee Lee1
1Radiology, Samsung Medical Center, Seoul, Seoul, Korea, 2Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Seoul, Korea, 3Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul, Seoul, Korea

We examined the functional and anatomical changes of somatosensry cortex in rats recoverying from severe neonatal hypoxic-ischemic encephalopathy (HIE) brain injury. In BOLD fMRI, the left brain activation was revelaed for the left forepaw stimuatlion in HIE rats with an evidence of functional and anatomical disconnection between left and right hemisphere using resting state fMRI and DTI. But more fiber tracks were observed in frotnal brain in the HIE rats than sham-operated rats. In this study, therefore, we found the inter- and intra-hemispheric brain reorganization to compensate for impaired somatosensory fuctnion in HIE rast at 9 weeks after inducing hypoxic-ischemic brain injury.

1863.   Evaluation of parametric response map (PRM) as an imaging biomarker in the study of a cell therapy in stroke
Rui He1,2, Benjamin Lemasson1,2, Anaïck Moisan1,2, Olivier Detante2,3, Chantal Rémy1,2, Alexandre Krainik2,3, and Emmanuel Luc Barbier1,2
1U836, Inserm, Grenoble, France, 2Grenoble Institut des Neurosciences, University Grenoble 1, Grenoble, France, 3Grenoble University Hospital, Grenoble, France

Twenty rats underwent stroke (transient middle cerebral artery occlusion, MCAo) and 12 sham surgery. At Day8, MCAo rats received an intravenous injection of either cell suspension medium (n=10) or of human mesenchymal stem cells (hMSCs, n=10). ADC was mapped at 7T from Day3 to Day16. ADC changes were assessed by parametric response map (PRM), a voxel-based analysis. PRM showed that the fraction of the lesion with decreased ADC was significantly higher in MCAo-PBS than MCAo-hMSC at Day9, suggesting that hMSCs decreased the post-ischemic cellular edema. This difference revealed by PRM, was masked by mean-value comparisons.

1864.   Time-to-Peak of T2*-Weighted Signal Change of Oxygen Challenge as a Biomarker of Penumbra
Qiang Shen1, Shiliang Huang1, and Timothy Q Duong1
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

Percent change of T2*-weighted signal following oxygen challenge (OC) has been used as a biomarker of penumbra. However, T2*-weighted MRI of OC challenge in delineating tissue at risk has low contrast-to-noise sensitivity and there are significant false positive and negative pixels, particular from pixels that contain large vessels. In order for this biomarker to be practical, it is necessary to improve its specificity and sensitivity. The goal of this study was to explore the use of the time-to-peak of OC response to further improve the identification of at-risk tissue in ischemic stroke.

1865.   Correlations of Structural and Functional Connectivity Alterations in Primary Motor Cortex in a Macaque Model of Ischemic Stroke
Yuguang Meng1, Frank Tong2, Chunxia Li1, Stuart Zola1, Leonard Howell1, and Xiaodong Zhang1
1Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2School Of Medicine, Emory University, Atlanta, GA, United States

Structural and functional alterations in primary motor cortex are generally observed in stroke patients and animal models. However, the temporal correlation between the both alterations after stroke insult is not completely understood. By using diffusion MRI and resting-state fMRI (rsfMRI), the correlation between the ipsilateral structural damage and interhemispheric functional connectivity alterations in primary motor cortex was evaluated with a macaque model of ischemic stroke.

1866.   Asymmetric magnetization transfer effects for perfusion imaging in transient ischemic brain tissue in rats
Kazuhiro Nakamura1, Junko Kawamura1, Yasushi Kondoh1, Hajime Miyata1, and Toshibumi Kinoshita1
1Akita Research Institute for Brain and Blood Vessels, Akita, Akita, Japan

Several studies show post-ischemic hyperperfusion at 48 hours after reperfusion in the transient ischemic tissue using continuous arterial spin labeling (CASL) method. Asymmetric magnetization transfer (MT) effects have not been investigated in these studies. In our experiments, cerebral blood flow (CBF) using CASL method (CASL CBF) with minus polarities of the labeling gradient was higher than that with plus polarities. The results showing asymmetric MT effect in CASL CBF must be compensated even though the two-coil system. After compensation of the MT effect, CASL CBF at 48 hours after reperfusion was still significantly higher than at 24 and 72 hours.

1867.   Combination normobaric oxygen and methylene blue treatment delays the progression of ischemic penumbra into infarct and promotes behavioral recovery
Pavel Rodriguez1,2, Jiang Zhao2, Brian Milman3, Lora Talley Watts2, and Timothy Q. Duong2
1Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 2Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, 3School of Medicine, University of Texas Health Science Center at San Antonio, Texas, United States

We previously reported that methylene blue (MB) – an energy enhancing and antioxidant – reduces infarct volume in 60-mins and permanent MCAO in rats. This study investigated the combination therapy of MB and normobaric oxygen (NBO) treatment in ischemic stroke. We hypothesized that MB+NBO treatment delays infarct growth and salvages more tissue than NBO + Vehicle treatment alone in a 60-min MCAO model in rats and that longitudinal MB treatment promotes faster motor functional behavioral recovery.

1868.   Evolution of Fractional Anisotrophic Changes In An Animal Model of Ischemic Stroke: Relative Contribution of Anisotropic Versus Magnitude Diffusivity
Cheng-Yu Chen1,2, Duen-Pang Kuo3,4, Hsiao-Wen Chung4, Chen Chang5, and Ping-Huei Tsai1
1Department of Medical Imaging and Imaging Research Center, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan, 2Graduate Institue of Clinical Medicine, Taipei Medical University, Taipei, Taiwan, 3Department of Radiology, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan, 4Graduate Institute of Biomedical Electrics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 5Functional and Micro-magnetic Resonance Imaging Center, Academic Sinica, Taipei, Taiwan

Although FA is one of the most common indices used in diffusion tensor imaging reflecting the brain microstructural changes, the FA changes in acute ischemic stroke may not be specific due to two components, q and L, included. Therefore, the aim of our study is to investigate the differential behaviors of q and L in the ischemic penumbra versus the infarct core using a longitudinal rat stroke model. Our preliminary result suggests that q may detect stroke-related abnormality with a higher sensitively than L, and the relative stable q in ischemic penumbra may provide insight into the definition of salvageable brain tissue in hypoperfused brain at acute setting.

1869.   Longitudinal microstructural white matter changes in a transient focal ischemic stroke rat model using a tract-based spatial statistics (TBSS) method
Won Beom Jung1, Jae Hun Kim2, Geun Ho Im1, Moon Sun Jang1, Kyoung Nam Kim1, Julius Juhyun Chung3, Sun Young Chae3, and Jung Hee Lee1,2
1Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Korea, 2Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, 3Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul, Korea

In this study, we examined the microstructural white matter changes after ischemia in rats over time from acute (4 hours) and sub-acute (1 week) to chronic (3 and 6 weeks) stages using tract-based spatial statistics (TBSS) method. The frectional anisotropy (FA) values decreased in perilesional white matter tracks at sub-acute stage and gradually normalized from corpus callosum to external capsule at later stages. In addition, the mean diffusivity (MD) values decreased at acute stage and dramatically increased at later stages. We believe that the longitudinal FA changes ranging from decrease to normalization may reflect the recovery of ischemic brain damage by WM restoration.

Can Cortical Spreading Depolarization Serve as a Marker for Tissue Plasminogen Activator (tPA) Toxicity for Stroke Treatment?
Yu-Chieh Jill Kao1, Wenjing Li1, Weili Lin1,2, and Yen-Yu Ian Shih1
1Experimental Neuroimaging Laboraory, Department of Neurology and BRIC, University of North Carolina, Chapel Hill, North Carolina, United States, 2Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, United States

In this study, we aimed to demonstrate that: (i) controllable ischemic lesions can be generated in our model inside the MRI, and (ii) tPA will attenuate PIDs in mild ischemic injury and exacerbate PIDs in more severe injury.

1871.   Effects of Residual Oxygen Molecule on BOLD signal: MRI Study Using Spontaneously Breathing Brain Stroke model
Ji-Yeon Suh1, YoungKyu Song1, Jeong Kon Kim1,2, Young Ro Kim3, and Gyunggoo Cho1
1Magnetic Resonance Research, Korea Basic Science Institute, Cheongwon, Chungbuk, Korea, 2Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea,3Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, United States

BOLD signal has been accepted to have both signal changes, positive change by the deoxyHb decrease as well as negative change by oxygen paramagnetism. In this study, in order to evaluate the role of oxygen, the relaxation times and the MRI-derived blood volumes were measured with 21% and 100% O2 gas inhalations in ischemic rat brains. Our results demonstrated the excessive oxygen molecules remained in the stroke-affected tissues by the lack of oxygen metabolism have different actions in terms of R1 and blood volume changes, indicating that different levels of oxygen molecules may be related to the different changes of BOLD signals.

1872.   Localized blood brain barrier opening of the macaque brain using a high frequency multielement Focused Ultrasound transducer array and microbubbles
Mathieu David Santin1,2, Laurent Marsac3,4, Morgane Monfort2, Philippe Annic4, Chantal François2, Mathieu Pernot4, Stéphane Lehéricy1,2, Mickaël Tanter4, and Jean-François Aubry4
1CENIR, ICM, Paris, France, 2CNRS UMR7225, INSERM UMRS 975, UPMC, ICM, Hôpital Pitié-Salpêtrière, Centre de Recherche de l'Institut du Cerveau et de Moelle Epinière, Paris, France, 3SuperSonic Imagine, Aix en Provence, France, 4CNRS UMR 7587, INSERM U979, Institut Langevin, ESPCI ParisTech, Paris, France

This work presents a method for localized blood brain barrier opening of the macaque brain using a high frequency multielement Focused Ultrasound transducer array and microbubbles