PCT rCBV values for the healthy hemisphere
| Group | Sampling Interval | ||||||
|---|---|---|---|---|---|---|---|
| 0.5 second | 1 second* | 2 seconds | 3 seconds | 4 seconds | 5 seconds | 6 seconds | |
| 1 (30 mL) | |||||||
| Mean ± SD | 3.0 ± 0.4 | 2.8 ± 0.5 | 2.9 ± 0.4 | 3.0 ± 0.5 | 3.9 ± 0.7 | 4.8 ± 1.3 | 14.9 ± 4.8 |
| Range | −6.5% to +8.0% | NA | −7.5% to +6.8% | −6.2% to +9.2% | +16.8% to +59.4% | +52.5% to +99.1% | +136.0% to +628.3% |
| P value | .213 | NA | .700 | .124 | .004 | .002 | <.001 |
| 2 (40 mL) | |||||||
| Mean ± SD | 3.1 ± 0.5 | 3.0 ± 0.4 | 2.8 ± 0.4 | 3.2 ± 0.5 | 3.2 ± 0.6 | 4.3 ± 0.7 | 4.9 ± 1.2 |
| Range | −5.8% to +7.1% | NA | −8.3% to +4.9% | −5.8% to +7.4% | −4.2% to +9.6% | +18.0% to +69.3% | +42.0% to +278.2% |
| P value | .225 | NA | .595 | .0196 | .024 | <.001 | <.001 |
| 3 (50 mL) | |||||||
| Mean ± SD | 3.2 ± 0.4 | 3.1 ± 0.5 | 2.9 ± 0.4 | 3.0 ± 0.3 | 3.3 ± 0.5 | 3.9 ± 0.6 | 4.1 ± 0.8 |
| Range | −7.2% to +6.2% | NA | −9.0% to +7.9% | −7.4% to +8.3% | −5.3% to +8.3% | +7.9% to +41.6% | +22.3% to +66.6% |
| P value | .708 | NA | .243 | .494 | .139 | .008 | .007 |
| 4 (60 mL) | |||||||
| Mean ± SD | 3.2 ± 0.4 | 3.1 ± 0.5 | 2.9 ± 0.4 | 2.9 ± 0.3 | 3.2 ± 0.4 | 3.3 ± 0.4 | 3.7 ± 0.5 |
| Range | −6.5% to +8.0% | NA | −8.3% to +10.2% | −8.1% to +9.0% | −5.8% to +7.6% | −4.8% to +9.6% | +8.5% to +32.6% |
| P value | .230 | NA | .650 | .420 | .324 | .038 | .007 |
Note.—No significant difference (P = .908, 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.