PCT rCBV values for the ischemic area
| Group | Sampling Interval | ||||||
|---|---|---|---|---|---|---|---|
| 0.5 second | 1 second* | 2 seconds | 3 seconds | 4 seconds | 5 seconds | 6 seconds | |
| 1 (30 mL) | |||||||
| Mean ± SD | 1.0 ± 0.4 | 1.2 ± 0.5 | 1.1 ± 0.5 | 2.2 ± 0.4 | 3.7 ± 0.6 | 5.4 ± 1.5 | 12.1 ± 4.8 |
| Range | −14.4% to +8.6% | NA | −10.2% to +8.5% | +33.7% to +111.2% | +104.2% to +335.0% | +222.0% to +447.4% | +630.5% to +1275.2% |
| P value | .018 | NA | .519 | <.001 | <.001 | <.001 | <.001 |
| 2 (40 mL) | |||||||
| Mean ± SD | 1.1 ± 0.3 | 1.2 ± 0.4 | 1.1 ± 0.4 | 1.2 ± 0.4 | 3.2 ± 0.5 | 5.1 ± 0.9 | 10.9 ± 2.8 |
| Range | −13.0% to +13.7% | NA | −10.5% to +8.1% | −10.6% to +10.2% | +53.0% to +220.5% | +197.3% to +427.3% | +510.8% to +937.3% |
| P value | .156 | NA | .076 | .765 | <.001 | <.001 | <.001 |
| 3 (50 mL) | |||||||
| Mean ± SD | 0.9 ± 0.5 | 1.1 ± 0.3 | 1.0 ± 0.3 | 1.1 ± 0.6 | 2.3 ± 0.3 | 3.4 ± 0.5 | 4.3 ± 0.9 |
| Range | −12.4% to +10.6% | NA | −8.1% to +8.5% | −10.5% to +9.4% | +33.5% to +122.3% | +95.5% to +323.7% | +249.7% to +435.4% |
| P value | .021 | NA | .033 | .603 | <.001 | <.001 | <.001 |
| 4 (60 mL) | |||||||
| Mean ± SD | 1.0 ± 0.4 | 1.0 ± 0.5 | 0.9 ± 0.6 | 0.9 ± 0.4 | 1.1 ± 0.3 | 2.0 ± 0.3 | 2.4 ± 0.4 |
| Range | −11.3% to +10.4% | NA | −7.2% to +7.2% | −9.5% to +9.3% | −11.8% to +12.1% | +23.3% to +155.9% | +97.9% to +228.1% |
| P value | .614 | NA | .164 | .172 | .014 | <.001 | <.001 |
Note.—No significant difference (P = .556, Kruskal-Wallis) was identified among the four groups for rCBV values obtained with an interval of 1 second. Range indicates the overestimation or underestimation compared with the reference. Values in boldface indicate the temporal sampling interval thresholds beyond which rCBV values were significantly overestimated.
* Reference for Wilcoxon (Mann-Whitney) tests performed in each group. NA indicates not applicable.