Evaluation of regional cerebral circulation based on absolute mean transit times in radionuclide cerebral angiography

Abstract

In radionuclide cerebral angiography (RCA) the analysis of the activity-time curves recorded over the hemispheres following an intravenous bolus injection of a radioactive indicator permits the evaluation of absolute cerebral mean transit times (MTT_cb). The inverse of MTT_cb is an index of cerebral blood flow. The bolus parts of the cerebral activity curves were fitted with gamma-variate functions. The duration of the injection bolus and its subsequent dispersion through the cardiopulmonary circulation were corrected for using the activity curve over the aortic arch. The RCA is non-invasive, rapid, easy to perform and without risk for the patient. The RCA is recommended for quantitative evaluation of major alterations in cerebral perfusion.