Diffusion Tensor Imaging-Based Fractional Anisotropy Quantification in the Corticospinal Tract of Patients with Amyotrophic Lateral Sclerosis Using a Probabilistic Mixture Model
S.K. Schimrigka,
B. Bellenberga,
M. Schlüterc,
B. Stieltjesd,
R. Drescherb,
J. Rexiliusc,
C. Lukasb,
H.K. Hahnc,
H. Przunteka and
O. Kösterb
a Department of Neurology, St. Josef Hospital, Ruhr University of Bochum, Bochum, Germany
b Departments of Radiology and Nuclear Medicine, St. Josef Hospital, Ruhr University of Bochum, Bochum, Germany
c MeVis Center for Medical Diagnostic Systems and Visualization, Bremen, Germany
d Department of Radiology, German Cancer Center, Heidelberg, Germany

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Fig 1. Definition of the evaluation planes along the CST. Coronal view depicts the definition of positions 1 to 4. Axial views show the corresponding reformatted sections. The end points of the red lines correspond to the right CST location within the axial sections.
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Fig 2. FA quantification procedure. Optimal color-coding in the right branch of the CST at the level of the internal capsule. Top, ROI delineation with fiber bundles of interest (red) and the bordering fibers (green, blue). Bottom left, probability map of ROI; yellow, light green, and blue area voxels belong to fiber, background, or mixture tissue, respectively.
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Fig 3. Individual FA courses along the CST. Circles, healthy subject 1 and healthy subject 2; triangles: patient 1 and patient 2. Gray bars mark the ranges of position 1 to 4.
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Fig 4. FA as measured using evaluation strategies. A, B, C, and D are dependent on subject age. Mean values of corresponding measurements in the left and right branch of the CST. Black circles, control group. Gray circles, patients with ALS. Lines, linear regression of the control group with 95% confidence range.
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