Article Figures & Data
Figures
- 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.
- 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.
- 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.
- 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.
Tables
Patient/Age (y)/Sex Hypertension Diabetes Hyperlipidemia Affected Vessel Stroke Episode Time (mo) to Imaging From Diagnosis From Synptoms 1/68/M Yes Yes Yes L ICA stenosis TIA, aphasia 48 4 2/61/M Yes Yes Yes L MCA stenosis TIA, dysarthria 21 21 3/55/M Yes No Yes R ICA occlusion NA 130 NA 4/66/F Yes Yes Yes L MCA stenosis TIA, dysarthria 17 17 5/70/M Yes Yes No R ICA stenosis NA 4 NA 6/78/M Yes Yes Yes L ICA stenosis NA 3 NA Note.—NA = not applicable, TIA = transient ischemic attack.
ROI value Asymmetry Analysis Affected Hemisphere Unaffected Hemisphere P Value Standardized AI P Value Fast MD (10−3 sec/mm2) IC 0.67 ± 0.03 0.67 ± 0.03 860 1.00 (0.96–1.04) 882 WM-IC 0.76 ± 0.04 0.73 ± 0.04 071 1.05 (1.00–1.09) 045† WM-CR 0.78 ± 0.06 0.73 ± 0.03 054 1.06 (1.01–1.12) 034† WM-CS 0.73 ± 0.03 0.72 ± 0.04 595 1.01 (0.97–1.06) 569 Slow MD (10−3 sec/mm2) IC 0.30 ± 0.03 0.28 ± 0.04 168 1.09 (0.98–1.20) 126 WM-IC 0.33 ± 0.04 0.32 ± 0.03 419 1.01 (0.98–1.03) 655 WM-CR 0.32 ± 0.03 0.31 ± 0.02 107 1.02 (0.99–1.04) 128 WM-CS 0.31 ± 0.02 0.31 ± 0.02 473 0.98 (0.95–1.01) 316 Fast FA IC 0.65 ± 0.06 0.66 ± 0.05 421 0.98 (0.94–1.01) 194 WM-IC 0.42 ± 0.05 0.44 ± 0.05 142 0.95 (0.89–1.01) 179 WM-CR 0.38 ± 0.05 0.40 ± 0.03 416 0.95 (0.89–1.02) 328 WM-CS 0.37 ± 0.04 0.40 ± 0.02 151 0.94 (0.86–1.01) 112 Slow FA IC 0.67 ± 0.08 0.74 ± 0.10 045‡ 0.91 (0.84–0.98) 018† WM-IC 0.58 ± 0.10 0.61 ± 0.08 051 0.96 (0.92–1.00) 043† WM-CR 0.55 ± 0.09 0.57 ± 0.07 137 0.96 (0.92–1.01) 108 WM-CS 0.54 ± 0.10 0.55 ± 0.09 483 0.98 (0.90–1.05) 545 *Data in parentheses are th 95% CIs.
† Significant.
‡ Significant (paired t test).
