Quantitative Diffusion-Weighted MR Imaging in Transient Ischemic Attacks
Ayeesha K. Kamala,
Alan Z. Segala and
Aziz M. Ulu
b
a the Department of Neurology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY
b Department of Radiology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY
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FIG 1. A, Quantitative Dav map shows ROIs (boxes) in the location of clinically suspected region of brain (right motor cortex) and contralateral control site. These two measurements were used to calculate the ratio m1.
B, Quantitative Dav map shows regions used for measurements made on right and left thalami (boxes) for calculating the control ratio of c1.
C, Mean value of the brain tissue diffusion constant (BDav) and width of the distribution ( ) were determined from the distribution analysis map by using a three-compartmental model (see Methods). This value was used in determining the ratios m3 and c3. Data are shown as circles, and the fit is shown as a line.
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FIG 2. Four measured ratios (m1, m2, c1, c2) are shown for all 12 patients. TIA-affected regions are compared with corresponding contralateral brain regions (m1) and to thalamic controls (m2) not affected by TIA (solid symbols). The resultant ratios are consistently below unity and are around 0.82. However, when regions of brain not affected by the TIA are compared (c1, c2), no interhemisperic difference is noted and the ratios approach unity (open symbols).
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FIG 3. Patient with left hand and arm weakness (patient 8).
A and B, DW image (A) and T2-weighted image (B) of an axial section through the motor cortex do not show any abnormality.
C, Quantitative Dav map shows a dark region (arrow) in the right motor cortex.
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