The diagnosis of brain death with Tc-99m HMPAO.

Evaluation of blood flow to the brain using various radiopharmaceuticals can be used to confirm brain death. Agents available for this purpose include Tc-99m HMPAO, Tc-99m pertechnetate, Tc-99m glucoheptonate, and Tc-99m DTPA. The authors evaluated the use of Tc-99m HMPAO in 17 patients suspected of brain death using flow images and static images at several time intervals: immediately, between 30 and 60 minutes, and at 2 hours. These studies were compared to several studies performed with Tc-99m glucoheptonate and Tc-99m DTPA. The results of the Tc-99m HMPAO brain death studies correlated well with the patients' clinical conditions. Static images 1 to 2 hours after the injection of 5 to 30 mCi of Tc-99m HMPAO were satisfactory for an accurate interpretation; however, an immediate answer could as easily be supplied using flow images alone. Tc-99m HMPAO was found to be more easily interpreted and less dependent on imaging technique than Tc-99m glucoheptonate and Tc-99m DTPA, and it is the agent of choice for the evaluation of brain death.