[Analysis of relative cerebral perfusion in ischemic cerebral diseases by single photon emission computed tomography using N-isopropyl-p-[123I]iodoamphetamine].

Semiquantitative analysis of 123I-IMP SPECT enabled to evaluate relative regional cerebral perfusion and redistribution rates. Two parameters were calculated; the relative perfusion rate (RPR) is the ratio of radioactivity on a localized lesion divided by radioactivity on the visual cortex, the redistribution rate (RR) is the ratio of RPR in late images at 3 hrs divided by that in early images at 15 min postinjection. Total of 45 patients with ischemic cerebral diseases were studied. There were 29 males and 16 females with the age ranging from 37 yr to 80 yr. The RPRs were 81.3 +/- 5.1% in TIA (14 cases), 63.6 +/- 10.6% in RIND (8 cases), 64.6 +/- 8.5% in mild infarction (9 cases) and 40.2 +/- 13.8% in severe infarction (14 cases). RPR on the lesion of the severe infarction was extremely low compared to that of TIA, RIND and mild infarction. RPRs of lesions in the mild and severe infarction were reversely correlated to the size of LDA on X-ray CT (p less than 0.01). RPR was well correlated to clinical status of ischemic diseases. The RRs were 1.18 +/- 0.08 in TIA, 1.41 +/- 0.20 in RIND, 1.28 +/- 0.15 in mild infarction and 1.21 +/- 0.31 in severe infarction. The RR of RIND was significantly higher than those of other categorized groups (p less than 0.01). The RR may prove useful as a parameter reflecting tissue viability in cerebral ischemic diseases.(ABSTRACT TRUNCATED AT 250 WORDS)