Highly Diffusion-Sensitized Tensor Imaging of Unilateral Cerebral Arterial Occlusive Disease
Atsushi Shiraishia,c,
Yasuhiro Hasegawaa,
Shunichi Okadaa,
Kazumi Kimuraa,
Tohru Sawadab,
Hidehiro Mizusawac and
Kazuo Minematsua
a Cerebrovascular Division, National Cardiovascular Center, Osaka
b BF Research Institute, Osaka
c Department of Neurology and Neurological Science, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Japan
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FIG 1. Double-exponential diffusional signal-intensity decays. Plot shows 1) the mean ± 1 SD (error bars) of Sb/S0 at b = 100–3300 s/mm2 in the centrum semiovale in six healthy volunteers and 2) the approximation to the double-exponential model according to the nonlinear least-squares Marquardt–Levenberg algorithm (line) plotted on a logarithmic scale. Also shown are b-value ranges for fast (A) and slow (B) DTI in patients 3–6.
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FIG 2. ROC curves for fast MD (green), slow MD (black), fast FA (red), and slow FA (blue) indicate estimated accuracies of 78.1%, 69.3%, 77.4%, and 89.8%, respectively. Accuracy of predicting the affected hemisphere was superior for MD on fast DTI and for FA on slow DTI.
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FIG 3. DTIs of patient 3 with right ICA occlusion: fast MD (3A), slow MD (3B), fast FA (3C), slow FA (3D), and color-scaled slow FA maps (3E) of MD (10–3 s/mm2) and FA. Arrows indicate affected hemispheres. In the absence of apparent T2 hyperintensities, the slow FA map of patient 3 demonstrated slight anisotropy declines at right internal capsule.
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FIG 4. DTIs of patient 4 with left MCA stenosis: fast MD (4A), slow MD (4B), fast FA (4C), slow FA (4D). Slow FA map shows broad anisotropy declines in the left hemisphere at all levels shown.
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