An unusual cause of apparent regional hyperperfusion on radionuclide cerebral angiography study: case report

An unusual pattern of radioactivity in the venous phase was noted in the 99mTc-DTPA cerebral angiogram of a patient with persistent headaches. Initially the possibility of a small arteriovenous malformation with large draining veins was considered. However, contrast angiography revealed dilated cerebral veins with significant arteriovenous shunting. The differential diagnosis of regional hyperperfusion on the radioactivity study is discussed.