Perfusion MRI for Preoperative Grading of Intracranial Meningiomas: A Systematic Review and Meta-Analysis

Background/Objectives: A reliable preoperative estimate of World Health Organization (WHO) grade 2–3 meningiomas could complement existing criteria when planning surgery and follow-up. We assessed whether perfusion magnetic resonance imaging (MRI) parameters differ between grade 1 and grade 2–3 meningiomas. Methods: PubMed, Embase, Scopus and Web of Science were searched to 6 October 2026 (OSF registration 10.17605/OSF.IO/G3Q9M). Standardised mean differences (Hedges’ g) of dynamic susceptibility contrast (DSC), dynamic contrast-enhanced (DCE) or arterial spin labelling (ASL) parameters were pooled with random-effects models, separately for intratumoral and peritumoral measurements. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool and certainty with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Results: Ten studies (509 patients; 129 with grade 2–3 tumours) were included. Intratumoral relative cerebral blood volume (rCBV) showed no clear difference between grades (seven studies; g 0.13, 95% CI −0.71 to 0.98; p = 0.71, I2 = 84%, τ2 = 0.69). Peritumoral perfusion was higher around grade 2–3 tumours in all four studies that measured it, but the exploratory pooled estimate was imprecise (g 2.32, 95% CI −0.02 to 4.66, p = 0.051, I2 = 93%, τ2 = 2.03). Diagnostic accuracy could not be pooled. Certainty of evidence was very low. Conclusions: Current evidence does not show that intratumoral rCBV distinguishes meningioma grades. Higher peritumoral perfusion in grade 2–3 tumours, which may partly reflect peritumoral oedema, is a hypothesis to be tested in prospective studies using the 2021 WHO classification and pre-specified thresholds.