INITIAL EXPERIENCE WITH SPECT (SINGLE-PHOTON COMPUTERIZED-TOMOGRAPHY) OF THE BRAIN USING N-ISOPROPYL I-123 P-IODOAMPHETAMINE - CONCISE COMMUNICATION

Abstract

Patients (46) were studied with N-isopropyl 123I p-iodoamphetamine (IMP) and the Harvard Scanning Multidetector Brain System. In 9 control patients, good differentiation between the gray and white matter of the cerebral cortex and the basal ganglia was evident. Regional uptake was affected by physiological maneuvers (visual stimulation). In 24 patients studied for stroke, IMP images demonstrated areas that were involved in acute infarction in 8 patients whose initial transmission computerized tomography (TCT) was normal; IMP also showed perfusion abnormalities larger than the TCT abnormality in 10 patients. Perfusion abnormalities were present in 23/24 of these patients. Seven patients studied with a history of TIA [transient ischemic attack] had normal TCT and IMP images. In 3 patients studied during seizure activity, regions of hyperperfusion corresponded to the EEG seizure focus. Markedly decreased activity was present in 3 patients with brain tumor and corresponded to the focal abnormality on the TCT study. The feasibility of assessing regional brain perfusion using a radiopharmaceutical that is lipid soluble and has a high extraction fraction in the brain, together with single-photon ECT [emission computed tomography] is demonstrated.