Simple delineation of misery perfusion areas by superimposition of PET on PET images.

Oxygen extraction fraction images were superimposed on cerebral blood flow images of positron emission tomography (PET) to depict the so-called misery perfusion area in two patients with moyamoya disease. The superimposed image following extra-intracranial bypass surgery was obtained in one case, which convincingly disclosed attenuation as compared with the preoperative image. This simple PET on PET approach should find an application in the evaluation of misery perfusion and in assessing operative indications for cerebral ischaemic diseases.