Systematic review of perfusion imaging with computed tomography and magnetic resonance in acute ischemic stroke: heterogeneity of acquisition and postprocessing parameters: a translational medicine research collaboration multicentre acute stroke imaging study.

BACKGROUND AND PURPOSE Heterogeneity of acquisition and postprocessing parameters for magnetic resonance- and computed tomography-based perfusion imaging in acute stroke may limit comparisons between studies, but the current degree of heterogeneity in the literature has not been precisely defined. METHODS We examined articles published before August 30, 2009 that reported perfusion thresholds, average lesion perfusion values, or correlations of perfusion deficit volumes from acute stroke patients <24 hours postictus. We compared acquisition parameters from published studies with guidance from the Acute Stroke Imaging Research Roadmap(1). In addition, we assessed the consistency of postprocessing parameters. RESULTS Twenty computed tomography perfusion and 49 perfusion-weighted imaging studies were included from 7152 articles. Although certain parameters were reported frequently, consistently, and in line with the Roadmap proposals, we found substantial heterogeneity in other parameters, and there was considerable variation and underreporting of postprocessing methodology. CONCLUSIONS There is substantial scope to increase homogeneity in future studies, eg, through reporting standards.