Table 2. Mean global cerebral blood flow in mL/100 g per minute (95% confidence intervals), test–retest variability, and mean difference to positron emission tomography arterial input function.
|
Baseline |
Acetazolamide |
||||||
|---|---|---|---|---|---|---|---|
| CBF method | Injected activity (MBq) | CBF 95% CI (mL/100 g per minute) | Test–retest (%) | ΔPET AIF (%) | CBF 95% CI (mL/100 g per minute) | Test–retest (%) | ΔPET AIF (%) |
| PET AIF | 100 | 27.6 (24.0; 31.7) | 7.7 | 64.4 (55.3; 74.9) | 9.8 | ||
| 20 | 27.4 (23.5; 32.1) | 5.7 | 64.0 (55.0; 74.5) | 8.9 | |||
| ASL | 100 | 29.5 (23.7; 36.7) | 8.6 | 2.3 | 76.8 (60.9; 96.8) | 8.2 | 19.3a |
| 20 | 24.7 (19.0; 32.1) | 18.8b | −11.3 | 80.7 (63.7; 102.2) | 11.7 | 27.3a | |
| PET IDIF | 100 | 33.6 (29.6; 38.1) | 5.9 | 21.8a | 78.6 (69.5; 88.9) | 9.0 | 22.1a |
| 20 | 34.0 (29.9; 38.8) | 12.4 | 22.1a | 73.7 (64.1; 84.7) | 10.7 | 15.1a | |
AIF, arterial input function; ASL, arterial spin labeling; CI; confidence interval; IDIF, image-derived input function; PET, positron emission tomography.
Global CBF values from seven healthy newborn piglets calculated as geometric means. Cerebral blood flow is given in mL/100 g per minute. Test–retest: absolute variability. ΔPET AIF: relative difference to PET AIF CBF. Missing values: one in PET AIF, six in ASL (four in baseline 100 MBq scans).
a
Significant difference (P<0.05) between methods by mixed linear model test.
b
Excluding an outlier gives test–retest 11.9% for 20 MBq scans.