Quantitative positron emission tomography and single photon emission computed tomography measurements of human cerebral blood flow.

Current methods using emission tomography to quantitate human regional cerebral blood flow (rCBF) are reviewed. The sensitivity and spatial resolution of single photon emission tomography are too low to correlate reliably rCBF with known anatomic landmarks in the brain. However, even if the superior imaging qualities of positron emission tomography are employed, the radiotracers of rCBF frequently do not fully meet the requirements of the models of tracer kinetics that are employed. Therefore, the methodology of reported rCBF studies using emission tomography to measure quantitatively human rCBF needs to be carefully evaluated.