Standardization of Input Function for Quantification of Regional Cerebral Blood Flow in N-isopropyl-p-[123I]iodoamphetamine SPECT

Abstract

Quantification of regional cerebral blood flow (rCBF) using N-isopropyl-p-[123I]iodoamphetamine (IMP) and single photon emission computed tomography (SPECT) requires continuous or frequent arterial blood sampling and accurate measurement of radioactivity of many blood samples. In order to avoid these invasive and troublesome procedures, a simplified method with a single blood sampling and two SPECT scans is proposed based on the two-compartment model We tried to find the optimum time of single blood sampling for calibration of the standardized input function. There were ten subjects; four patients with cerebrovascular disease, three with brain tumor, one with head trauma, and two healthy volunteers. Their ages ranged from 25 to 74 years with the average of 56.4 years. IMP (167 MBq) was infused into the right cubital vein at a constant rate in 15 s. Following the start of IMP infusion, arterial blood was sampled from the left radial artery every 15 s for 2 min, every 30 s for the next 3 min, every 1 min fo...