[Quantification of regional cerebral blood flow at the control state and loaded with diamox using split-dose...

The purpose of the study is to develop a simple and less invasive method for quantifying regional cerebral blood flow (rCBF) at pre- and post Diamox test using split-dose 99mTc-ECD and SPECT. By employing a microsphere model, integral of input function was calculated by the one-point venous sampling method previously reported. The study was performed on 5 subjects with cerebrovascular diseases. A split dose of 99mTc-ECD was injected pre- and post Diamox injection, and rCBF was measured by two SPECT scans and single venous samples, respectively. Mean CBF obtained by the present method was 0.47 +/- 0.07 ml/g/min at the control state, and 0.63 +/- 0.12 ml/g/min loaded with Diamox (mean % increase; 35%), showing good agreement with those obtained by the 133Xe-inhalation method. Since the present method does not require arterial blood sampling, dynamic data acquisition and dose corrections, it is simple, less invasive and useful in clinical SPECT studies.