Meta-analysis finds no significant differences between pCASL and DSC perfusion MRI in hyperacute ischemic stroke

A systematic review and meta-analysis examined the reliability of pseudocontinuous arterial spin-labeling (pCASL) MRI in ischemic stroke and its comparability with other perfusion techniques. The analysis included data from 383 participants with ischemic stroke, comparing pCASL against dynamic susceptibility contrast (DSC) MRI, computed tomography perfusion (CTP), and positron emission tomography (PET). The primary outcome was test-retest reliability of pCASL-derived cerebral blood flow measurements.

For the hyperacute phase of ischemic stroke, the analysis found no significant differences between pCASL and DSC MRI for infarct core relative CBF (95% CI, -0.11 to 0.13) or for hypoperfusion volumes (95% CI, -0.28 to 0.68). The single study assessing test-retest reliability reported no significant differences in repeated absolute CBF measurements over time, with excellent reliability across regions, though specific effect sizes and absolute numbers were not reported.

Safety and tolerability data were not reported. Key limitations include a small number of included studies that prevented meta-analysis for the primary outcome, only 1 low-quality, high-risk-of-bias study assessed test-retest reliability, and evidence on comparability with other techniques was limited. No PET studies were identified for comparison. The authors note robust conclusions could not be drawn due to limited evidence.

For clinical practice, this analysis suggests pCASL may show promise for perfusion assessment in hyperacute ischemic stroke when compared with DSC MRI, but the evidence base remains insufficient to support definitive conclusions about its reliability or broader comparability with established techniques. Further high-quality studies are needed before clinical implementation can be recommended.