Abstract
The usefulness of Cerebral Blood Flow (CBF) measurement by single photon emission computed tomography (SPECT) has been verified in patients with hyperacute stage of cerebral infarction, especially when a thrombolytic therapy is considered. Measuring residual CBF before thrombolysis is very important because patients with more than 40% decrease in CBF compared with the contralateral normal brain is at high risk of crucial hemorrhage after recanalization. Positron emission tomography (PET) can provide metabolic information of the ischemic brain in addition to the severity of CBF deterioration, and would be a powerful diagnostic tool if the measurement becomes feasible in emergency. We investigated qualitative PET measurement that took only half an hour for the examination, and demonstrated that qualitative PET could detect areas with misery perfusion in the affected cerebral hemisphere. Comparing the qualitative PET imaging with the functional magnetic resonance imaging (MRI) obtained within 6 hours after ischemic attack, we delineated that areas with perfusion-diffusion mismatch on MRI contained the area with decrease of oxygen metabolism where progressed to the irreversible brain damage without initial decrease of water diffusion. Qualitative PET measurement has the possibility to explicate the background of signal change of functional MRI that per-formed in the hyperacute stage of cerebral infarction.
