TRADITIONAL POSTER - ismrm

Poster Sessions
2438. Standard and Probabilistic Models of Diffusion Tensor Imaging and Tractography in Patients with
Brain Tumors
Zhixi Li 1 , Robert J. Young 2,3 , Kyung Peck 4 , Nicole Brennan 2 , Andrei I. Holodny 2,3
1 Columbia University College of Physicians and Surgeons, New York, United States; 2 Department of Radiology, Memorial Sloan-
Kettering Cancer Center, New York, United States; 3 Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, New York,
United States; 4 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, United States
The development of diffusion tensor (DT) imaging and tractography affords the ability to account for the white matter fibers and has the potential to be an
important tool in neurosurgical navigation. In addition to the usual fiber tracking challenges related to small fibers that may make sharp turns and/or
encounter crossing fibers, tractography in patients with brain tumors may be compromised by the tumor and/or the associated edema. In patients with brain
tumors near the arcuate fasciculus, we hypothesize that tractography based on a probabilistic model will perform better than a standard deterministic model.
2439. Mapping the Language Network in Grade II Gliomas: A Longitudinal Study with FMRI, MR
Tractography and Neuropsychology
Alberto Bizzi 1 , Francesca Ferrè 2 , GianMarco Castelli 1 , Maria Luisa Mandelli 1 , Sylvie Piacentini 2 ,
Francesca Ciaraffa 1 , Domenico Aquino 1 , Carlo Marras 3 , Francesco Di Meco 3 , Giovanni Broggi 3 , Carlo
Lazzaro Solero 3
1 Neuroradiology, Fondazione Istituto Neurologico Besta, Milan, Italy; 2 Neurology, Fondazione Istituto Neurologico Besta, Milan,
Italy; 3 Neurosurgery, Fondazione Istituto Neurologico Besta, Milan, Italy
Fourteen patients with grade II glioma were evaluated longitudinally with fMRI and DTI-MR Tractography of the language network and Aachener Aphasie
Test before surgery, at 3 and 12 months. Functional cortex and streamlines of the dorsal and ventral language pathways were mapped.
Deficits in phonemic and semantic fluencies were prevalent in patients with glioma infiltrating the insula, temporal pole and stem and were associated with
ventral pathway interruption. Left hemisphere dominance was preserved in most patients. These imaging data suggest that ipsilateral rather than contralateral
mechanisms of functional reorganization of the language network are more common in grade II gliomas.
2440. Role of Diffusion Tensor Imaging in Diagnosis of Medial Temporal Lobe Epilepsy
Heba Ali 1 , Mona Mohamed 2 , Yosra Abdullah, Ahmed Gaber, Yasser Abbas
1 AIN SHAMS UNIVERSITY HOSPITALS, CAIRO, Egypt; 2 JOHNS HOPKINS UNIVERSITY SCHOOL OF MEDICINE,
BALTIMORE, MD, United States
Modern MR techniques are helpful in assessment of patients presenting with seizures and EEG changes suggestive of temporal lobe epilepsy, yet having
normal conventional magnetic resonance imaging (MRI) epilepsy protocol. Here, we performed diffusion tensor imaging (DTI), with quantitative
assessment of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) combined with tractography for pertinent white matter tracts. Results
revealed that DTI is helpful for more accurate assessment of patients with MTLE.
2441. Impaired Structural Connectivity of Language and Memory Networks in Patients with Chronic
Epilepsy
Maarten Vaessen 1,2 , Jaap Jansen 3 , Paul Hofman, Marielle Vlooswijk, Henriette Majoie, Mark de Krom,
Albert Aldenkamp 1,2 , Walter Backes
1 School for Mental Health and Neuroscience , Maastricht University Medical Centre, Maastricht, Limburg, Netherlands;
2 Kempenhaeghe Epilepsy Institute, Heeze, Netherlands; 3 Memorial Sloan-Kettering Cancer Center, New York, NY, United States
Patients with chronic epilepsy commonly develop cognitive co-morbidity. Previously, it was observed that their declined cognitive performance was
associated with loss of functional connectivity derived from functional MRI of memory and language tasks. In this study we aimed to identify impaired
structural connections, obtained with fibre tractography, between brain regions commonly associated with language and memory function. We found that
fiber connections between the left and right frontal lobe were significantly reduced in these patients and were correlated with IQ.
2442. Longitudinal Diffusion Tensor Imaging of Fornix Degeneration Following Epilepsy Surgery
Min Liu 1 , Donald Gross 2 , B.Matt Wheatley 3 , Christian Beaulieu 1
1 Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; 2 Neurology, University of Alberta, Edmonton, Alberta,
Canada; 3 Neurosurgery, University of Alberta, Edmonton, Alberta, Canada
Diffusion tensor imaging (DTI) may be a sensitive method of following the unique phases of Wallerian degeneration of injured white matter fibers in human
brain. Longitudinal DTI tractography of the fimbria-fornix was performed at several time points on three patients with temporal lobe epilepsy before and
after their anterior temporal resections (several times within the first week and 2-4 months post-surgery). The diffusion parameters of the ipsilateral fornices
showed unique dynamic changes, notably a reduction of parallel diffusivity acutely, while perpendicular diffusion curiously showed a smaller reduction
within the first week followed by the expected increase at chronic times.
2443. FACT, Probability Maps and Gibbs Tracking for Preoperative Fiber Tracking in Epilepsy Surgery
Irina Mader 1 , Constantin Anastasopoulos 1 , Valerij G. Kiselev 2 , Andreas Schulze-Bonhage 3 , Marco Reisert 2
1 Clinic for Neuroradiology, University Hospital Freiburg, Freiburg, Germany; 2 MR Physics, Department of Radiology, University
Hospital Freiburg, Freiburg, Germany; 3 Section for Pre-surgical Epilepsy Diagnostics, Clinic for Neurosurgery, University Hospital
Freiburg, Freiburg, Germany
Problem: The protection of functional fiber bundles is essential in epilepsy surgery. The aim was to compare FACT, probability maps and Gibbs tracking in
their relevance for the neurosurgeon. Methods: Ten patients received pre-operative fiber tracking (5 corticospinal tract, 5 optic radiation). Results:
Probability maps and GIBBS tracking were successful for all fiber structures on the healthy and the pathologic side, whereas FACT was only successful in 5