Prediction of the final infarct volume within 6 h of stroke using single photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime

Background: A simple method to predict the final infarct volume within 6 h of onset of hemispheric ischemic stroke based on the measurement of cerebral blood flow (CBF) using single photon emission computed tomography (SPECT) with techneticum-99m hexamethylpropylene amine oxime (Tc-99m-HMPAO) was investigated in a clinical model involving patients without definite early reperfusion or clinical recovery. Methods: A group of 16 patients (group 1) was used to establish the methodology, which was then validated in a second group of 14 patients (group 2). The final infarct volume was defined using computed tomography (CT) performed at least 7 days after stroke. The relative CBF threshold value, expressed as a percentage of the mean contralateral hemispheric value, which most closely estimated the final infarct size on coregistered CT was established for each patient. Results: The mean threshold CBF value for group 1 was 63.7%. When this value was used to predict infarct size in group 2, a close correlation was observed between the actual and the estimated sizes (r = 0.973, p < 0.0001). This value was not time dependent. Conclusions: If no significant early reperfusion or clinical recovery occurs, a CBF threshold value of 63.7% on Tc-99m-HMPAO SPECT performed within 6 h of stroke onset will reliably predict the final infarct size. Copyright (C) 2001 S. Karger AG, Basel.