Table 2. Qualitative and Quantitative Analysis of M1 Segment of MCA.
| Method of Measurements | PAD | SAD | P | ||
|---|---|---|---|---|---|
| Visual enhancement score,† n (%) | Lesion side | 0 | 1 (6.7) | 5 (50) | < 0.001* |
| 1 | 0 (0) | 4 (40) | |||
| 2 | 14 (93.3) | 1 (10) | |||
| Contralateral side | 0 | 10 (66.7) | 4 (40) | 1.000 | |
| 1 | 5 (33.3) | 6 (60) | |||
| 2 | 0 (0) | 0 (0) | |||
| Volume of measured M1 (mm3) | Lesion side | 69.26, 59.05–81.65 | 66.70, 43.74–86.02 | 0.454 | |
| Contralateral side | 67.07, 62.69–78.73 | 64.88, 56.86–72.90 | 0.304 | ||
| Stenosis† (%) | Lesion side | 53.7, 11–66.67 | 8.17, 1.87–12.99 | 0.006* | |
| Contralateral side | 10.61, 4.04–12.85 | 8.14, 2.54–14.75 | 0.803 | ||
| GM† | Lesion side | 0.68, 0.56–0.82 | 0.47, 0.29–0.70 | < 0.001* | |
| Contralateral side | 0.37, 0.31–0.52 | 0.32, 0.26–0.37 | 0.183 | ||
| 90P† | Lesion side | 1.15, 0.96–1.38 | 0.62, 0.57–0.71 | < 0.001* | |
| Contralateral side | 0.62, 0.57–0.67 | 0.58, 0.50–0.68 | 0.605 |
Volume of measured M1, stenosis, GM and 90P were presented in median and interquartile ranges. Visual enhancement score: grade 0, enhancement was similar to or less than that of intracranial arterial walls without plaque in same individual; grade 1, enhancement was greater than that of grade 0 but less than that of pituitary infundibulum; and grade 2, enhancement was similar to or greater than that of infundibulum. *Parameters were significantly different between lesion side and contralateral side in Mann-Whitney U test (p < 0.001), †Visual enhancement score, Stenosis, GM, and 90P were significantly different between lesion side and contralateral side in large vessel disease group in Wilcoxon signed rank test (p < 0.001). GM = geometric mean, MCA = middle cerebral artery, PAD = parent artery disease, SAD = small artery disease, VOI = volume of interest, 90P = 90th percentile of normalized signal of VOI of M1