TRADITIONAL POSTER - ismrm

Poster Sessions
Pittsburgh, PA, United States; 4 Department of Medicine, National Taiwan University, Taipei, Taiwan; 5 Division of Psychology,
School of Humanities and Social Sciences, Nanyang Technological University, Singapore
We measured the generalized fractional anisotropy (GFA) of the auditory nerve (AN) to bilateral Heschl's gyri via the corpus callosum (CC) using diffusion
spectrum imaging (DSI). The individual language asymmetry was determined using fMRI. The left lateralized AN was found to be related to the leftward
language asymmetry. The mild lateralization in the AN as well as the lower GFA in the CC tend to have relationship with the bilateral language function.
The findings provide plausible evidence for the degree of conductivity of the AN as well as the CC in determining language lateralization/asymmetry
between the hemispheres.
1656. Performance of Deterministic and Probabilistic Diffusion Tensor and Q-Ball Corticospinal
Tractography in Brain Tumor Patients
Monica Bucci 1 , Maria Luisa Mandelli 2 , Jeffrey I. Berman, Bagrat Amirbekian 3,4 , Christopher Nguyen,
Mitchel S. Berger 5 , Roland G. Henry
1 Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 2 Department of
Neuroradiology, Istituto Neurologico Carlo Besta, Milano, Italy; 3 Radiology and Biomedical Imaging, University of California, San
Francisco; 4 UC Berkeley and UCSF Graduate Program in Bioengineering; 5 Department of Neurological Surgery, University of
California San Francisco
There are different methods available for fiber tracking but only with few methods it is possible to quantify the accuracy and precision in clinical
applications. We used preoperative HARDI data from patients with cerebral glioma to obtain corticospinal fiber tracts with deterministic and probabilistic
Diffusion Tensor and Q-Ball fiber tracking algorithms using cortical and subcortical stimulation sites from IES as gold standard. The functional motor sites
allows determination of the false negative rate of connectivity, which reflects the accuracy of the tractograms. The subcortical stimulation sites enable
determination of the accuracy and precision of the course of the predicted CST.
1657. Diffusion Tensor Imaging of Basal Ganglia Output Fibers
Mihaela Onu 1 , Uta Nicola Sboto-Frankenstein 2 , Patricia Gervai 2 , Greg Molnar 3 , Boguslaw Tomanek 2
1 Biophysics, University of Medicine "Carol Davila", Bucharest, Romania; 2 National Research Council Institute for Biodiagnostics;
3 Medtronic Inc.
The current study was designed to investigate if it is feasible to use MRI Diffusion Tensor Imaging to visualize basal ganglia output fibers, in particular the
Ansa Lenticularis (AL) and Lenticular Fasciculus (LF). Using the Globus Pallidus Internus (GPi) as a seed point, two fiber branches were identified. One
originated in the dorsal aspect of the GPi and the second in the ventral aspect of the GPi. These two tracts may be indicative for the localization of the LF
and AL respectively.
1658. Asymmetric Structural Connectivity of Default-Mode Network : An Integrated Study of FMRI and
Probabilistic DTI
Tzu-chen Yeh 1 , Chou-Ming Cheng 1 , Zong-Kai Hsu 2 , Jen-Chuen Hsieh 2 , Low-Ton Ho 1
1 Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan; 2 Institute of Brain
Science, National Yang-Ming University, Taipei, Taiwan, Taiwan
The spatial template of default-mode network (DMN) of sixty normal subjects has been constructed as five regions of interest (ROIs) as precuneus/posterior
cingulate areas with the highest reproducibility. Multimodal approaches using BOLD-based fMRI and probabilistic DTI (pDTI) demonstrated the limited
structural connectivity within each ROI within DMN correlates. By penetration maps of pDTI in twenty-two normal subjects, asymmetry of bilateral
cingulum cortices implied preference of right posterior medial parietal regions for interpretation of internal/external environment with concert action of
medial prefrontal areas, as one of the potential functions of DMN.
1659. Language Circuits of Human Brain: An Integrated Study of FMRI and Probabilistic DTI
Zong-Kai Hsu 1 , Tzu-Chen Yeh 2,3 , Chou-Ming Cheng 2 , Wen-Jui Kuo 4 , Jen-Chuen Hsieh 5
1 Institute of Brain Science , National Yang Ming University , Taipei, Taiwan; 2 Laboratory of Integrated Brain Research, Department
of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; 3 Institute of Brain Science , National Yang
Ming University, Taipei, Taiwan; 4 Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan; 5 Institute of Brain
Science, National Yang Ming University, Taipei, Taiwan
The language anatomical model proposed that Broca¡¦s area located in the inferior frontal lobe and Wernicke¡¦s area located in the superior temporal gyrus
were connected through the arcuate fasciculus (AF). Hickok and Poeppel [1] and others recently proposed a dual stream model for auditory language
processing. From the superior temporal gyrus, which is engaged in early cortical stages of speech perception, the system diverges into two processing
streams. The aim of this study is to examine the language circuits of the dual stream model using visual perception by an integrated functional MRI (fMRI)
and probabilistic diffusion tensor imaging (pDTI) method.
1660. Resolution-Dependent Differences in Fiber Tracking and Quantification of the Visual Pathways
Jan Klein 1 , Peter Erhard 2 , Horst Karl Hahn 1
1 Fraunhofer MEVIS, Bremen, Germany; 2 FB 2 (Chemistry) and Center of Advanced Imaging (CAI), Germany
Fiber tracking and quantification of the visual pathways is still a challenging problem due distortions in the vicinity of the optic nerve, the small diameter of
the bundle itself, crossing fibers in the optic chiasm and the capsula interna, the high curvature in the Meyers loop, and the discontinuity in the corpus
geniculatum laterale. We examine how changes in the resolution of the DTI data sets influence the fiber tracking and quantification of the visual pathways,
and show that an anisotropic resolution with a high coronal in-plane resolution should be preferred to an isotropic resolution with the same volume per
voxel.