Reproducibility of a non-invasive quantitative assessment of cerebral blood flow using 123I-IMP SPECT

A single venous blood sampling is clinically useful as a simple noninvasive method for quantitatively assessing cerebral blood flow (CBF). The present study was thus undertaken to determine its reproducibility. Of 25 patients receiving second or more I-123 IMP SPECT studies, 22 were eligible for the study. They consisted of 4 with cerebral infarction, 3 with cerebral hemorrhage, one with chronic subdural hemangioma, 2 with senile dementia of the Alzheimer's type, and two normal patients. The interval from the 1st to the 2nd study ranged from 14 to 225 days, with an average of 128±58 days. There was good correlation between the 1st and 2nd studies for CBF values in the bilateral frontal, temporal, and occipital lobes. For the bilateral parietal lobes and cerebellum, however, no correlation existed between the 1st and the 2nd studies. Mean CBF values in the 1st study for the whole cerebrum were well correlated with those in the 2nd study (r=0.80). Correlation coefficient for the normal area was r=0.80, which was as high as that for the pathologically affected area (r=0.86). The noninvasive method for the quantitative CBF assessment was considered to have high reproducibility from the clinical point of view. (N.K.)