HMPAO-Tc99m SPECT in brain death

99mTc-labeled hexamethylpropyleneamineoxime (HMPAO), and subsequent imaging with single photon emission computed tomographic (SPECT) brain scintigraphy.
The top figures show anterior posterior and lateral views of a normal scan with uptake in the brain. The bottom figures (same sequence) show lack of brain perfusion and the "empty light bulb" and "hot nose" signs.