Comparison of N-isopropyl (I-123) p-iodoamphetamine brain scans using Anger camera scintigraphy and single-photon emission tomography.

Abstract

N-isopropyl (123I) p-iodoamphetamine (IMP), which is extracted by the brain in proportion to regional blood flow, is useful with single-photon emission tomography (SPECT) in the assessment of pathologic states related to blood flow. Because emission tomographic equipment is not yet available at most hospitals, IMP brain images obtained with an Anger camera were compared with those obtained by SPECT to determine the usefulness of IMP scintigraphy. Pairs (39) of studies were performed on 12 control patients, 14 with stroke, 3 with tumors and a miscellaneous group of 8 patients. Planar scintigraphy showed good correlation with SPECT in determining the presence or absence of abnormality in all patients except one with a very small brain stem infarction that was not detected by planar imaging. Anger images showed poor contrast resolution compared with SPECT images. Apparently, SPECT results in better lesion detection when smaller lesions are studied. Planar scintigraphy is not capable of providing quantitative measurement of regional cerebral blood flow.