[Reproducibility of regional cerebral blood flow measurement at rest with autoradiography method using 123I-IMP and SPECT].

Reproducibility of regional cerebral blood flow (rCBF) values obtained by the autoradiography (ARG) method with one SPECT scan and one point arterial blood sampling at 10 min after 123I-N-isopropyl-p-iodoamphetamine (IMP) infusion was evaluated. The variation in the cross calibration factor between SPECT counts and well-type scintillation counts remained 2.2% for 13 months. The error in rCBF by sampling time difference was less than 3% when sampling time was within 10 min +/- 30 sec after infusion. There was a favorable correlation between the rCBF values in two separate resting scans measured by the ARG method in 10 patients (r = 0.907). And the mean ratio of rCBF values by the second study to those by the first study in the cerebellum and cerebral lobes in 10 patients was 0.989 +/- 0.056 (mean +/- SD). There was no significant difference in rCBF values between two separate studies. Reproducibility of rCBF with the ARG method was proved to be good. The ARG method was thought to be useful for the assessment of treatment effects and clinical courses.