[A non-invasive quantitative measurement of cerebral blood flow using N-isopropyl-[123I]p-iodoamphetamine and single photon emission CT].

A non-invasive quantitative method using N-isopropyl-[123I]p-iodoamphetamine (IMP) was described for assessing regional cerebral blood flow (rCBF). Twenty four cases, composed of 11 patients with brain tumors, 9 patients having cerebrovascular disease and 4 other patients aged 15-73 years, all underwent the SPECT 133Xe inhalation method (Xe-SPECT) and IMP-SPECT using a Tomomatic 564. In the IMP-SPECT cases, 111-222 MBq (3-6 mCi) of IMP was injected intravenously and then sequential imaging was performed 9.5 +/- 1.2 (mean +/- SD) min (E1 image), 20.6 +/- 1.2 min (E2 image), 227.5 +/- 22.1 min (D1 image), and 236.6 +/- 22.4 min (D2 image) after the injection. The IMP-uptake value (counts/pixel/sampling time) in the region of interest (ROI), which was chosen in the non-affected cortex in the middle cerebral artery territory (MCAC), was counted on each image (E1 value, E2 value, D1 value and D2 value) and the E1/D1 ratios and E2/D2 ratios were consequently calculated. On the other hand, the absolute value of the ROIrCBF (Xe-rCBF) was obtained by Xe-SPECT. There were significant correlations noted between both the E1/D1 ratios and the E2/D2 ratios, and the Xe-rCBFs. Those correlation coefficients were found to be: r = 0.741 and 0.810 respectively. Based on this significant relationship, equations were deduced to involve the rCBF values by use of IMP-SPECT: y = Ax + B (y: rCBF, x: E1/D1 ratio (E2/D2 ratio), A = 52.8 (68.2), B = 6.3 (-14.9), where A and B indicate the slope and deviation of the regression line).(ABSTRACT TRUNCATED AT 250 WORDS)