TOMOGRAPHIC IMAGES OF BLOOD POOL AND PERFUSION IN BRAIN AND HEART

Abstract

A whole-body positron-emission transaxial tomograph (PETT III) was used to image the cross-sectional distribution of 13NH3 and 11CO-hemoglobin in the human brain and heart. Carotid and i.v. bolus injections of 13NH3 in the rhesus monkey had shown that 13NH4 is efficiently extracted by the brain and clears from it slowly (half-time, 40-50 min for carotid injections and 60-70 min for i.v. injections). The i.v. tomographic images in humans showed an excellent relationship between 13NH3 uptakes in the cortex, subcortical white matter, cerebellum and brain stem and normal blood perfusion or flow in these structures. Cerebral lesions with high (metastasis) and low (stroke) blood flows showed correspondingly high and low uptakes of 13NH3. Large- and small-vascular structures of the brain were also clearly seen in 11CO-hemoglobin tomographic images. Normal myocardium and the ventricular chambers were well defined, and a transmural anterior myocardial infarct was clearly shown. The effective combination of positron transaxial tomography and compounds labeled with positron-emitters provides a safe new method for quantitatively imaging hemodynamic and physiolgic functions of selected organs with good tomographic image quality.