Mean signal ratios and SD for quantitative and visual assessment of PWI: separated for cases with and without visually detected perfusion abnormalitiesa
| Cases with Visually Detected Perfusion Abnormalities | Cases without Visually Detected Perfusion Abnormalities | |||
|---|---|---|---|---|
| Visual Score, grade 0–3 (mean ± SD) | Signal Ratio (mean ± SD) | Signal Ratio (mean ± SD) | ||
| TTP | 2.14 ± 0.68 | 1.08 ± 0.02 | 0.99 ± 0.01 | |
| rMTT | 1.57 ± 0.88 | 1.31 ± 0.19 | 1.02 ± 0.04 | |
| rCBF | 1.12 ± 0.66 | 0.64 ± 0.16 | 1.03 ± 0.07 | |
| rCBV | 0.55 ± 0.38 | 0.83 ± 0.18 | 1.05 ± 0.07 | |
↵a Signal ratio of the quantitative assessment is calculated as the signal of the affected side divided by the signal of the normal side; in cases without visually detected perfusion abnormality, it means the signal of the left divided by the signal of the right side.