TOMOGRAPHIC ASSESSMENT OF CEREBRAL PERFUSION USING A SINGLE-PHOTON EMITTER (KRYPTON-81M) AND A ROTATING GAMMA-CAMERA

Abstract

Continuous carotid infusion of short-lived 81mKr (t1/2 [half-life] 13 s) yields an assessment of regional cerebral perfusion. This assessment can be obtained in 3 dimensions if activity is recorded with a rotating .gamma. camera and a computer to reconstruct 81mKr distribution in tomographic sections. These showed several advantages over conventional views: visualization of blood flow distribution within brain structures (gray and white matter, basal ganglia); more accurate location and evaluation of areas of relatively reduced or increased perfusion, better definition of patterns of collateral circulation and greater sensitivity and specificity in detecting and defining blood flow changes during physiological activation studies. A limitation of the 81mKr technique is its invasiveness. The combination of new advances in radiochemistry with single-photon emission computed tomography may result in accessible methods for assessing, noninvasively and in 3 dimensions, the behavior of cerebral function in man.