Single-photon emission computed tomography. A method of measuring cerebral blood flow in three dimensions (preliminary results of studies in patients with epilepsy and stroke)

The recent development of single-photon emitting radiopharmaceuticals that reflect cerebral blood flow has introduced a new era for the useful application of nuclear medicine to the investigation of neurological disease. Using ¹²³I labelled N-isopropyl-p-iodoamphetamine, we have performed emission-computed tomographic scans of the brain in several clinical settings. These studies display cross-sectional maps of cerebral blood flow and promise significant clinical utility in a variety of brain diseases. In the eight patients with epilepsy, the scans showed good localization of the abnormal foci, and correlated well with the findings at operation in the five patients who were submitted to surgery. All 10 patients with stroke had abnormal scans, and the abnormalities in cerebral blood flow were frequently more extensive than the lesions seen on the transmission-computed tomographic scan. This initial experience leads us to anticipate an increasing role in clinical neurology for single-photon emission computed tomographic scans of cerebral blood flow.