TC-99M-HMPAO CEREBRAL SCINTIGRAPHY IN THE DIAGNOSIS OF BRAIN-DEATH

In order to determine the interest of Tc-99m-HMPAO brain imaging in assessing brain death, we studied 17 clinically brain dead patients. The results were compared with other available data: cerebral angiography, computed tomography and electroencephalography (EEG). In 14/17 studies there wase no evidence of intra-cranial blood flow ; HMPAO imaging showed an absence of brain uptake. Carotid angiography was negative (cerebral blood flow arrest) in one case while HMPAO imaging showed cerebellar uptake of the tracer. This was confirmed later with selective vertebral angiography. In another case, diagnosis of carotido-cavernous fistula was suspected and confirmed by carotid angiography. In the last case, there was evidence of left temporo-parietal uptake on HMPAO imaging ; the angiographic data was confirmatory, showing a patent left anterior cerebral artery. Compared to the conventional method, this molecule provides uniequivocal results and avoids contrast medium toxicity. We conclude that HMPAO imaging is a simple and non-invasive, method to confirm brain death.