As stated earlier, increased, decreased, or no change in perfusion does contribute to the differential evidence in the diagnosis of cerebral lesions. For example, a 40-year-old man developed right-sided symptoms over a period of several months. The static images revealed an area of increased activity of the left cerebral hemisphere, limited to the cortex, and correlated with the configuration of the rolandic branch of the left-middle cerebral artery. From the static images the lesions was interpreted as a possible arteriovenous malformation, or as a lesser possibility, a progressive stroke. The dynamic study demonstrated early concentration of radioactivity in the correct location that persisted through the dynamic sequence and did not wash out. This evidence suggested a neoplasm, probably an enplaque meningioma that was found at subsequent surgery
