Introduction Distal medium vessel occlusions (DMVOs) are common and often disabling, and the optimal imaging method for its diagnosis is yet to be defined.

Aim of Study To perform a systematic review and meta-analysis of studies to compare the diagnostic performance of CT angiography (CTA) and CT perfusion (CTP) in detecting DMVOs.

Methods We screened PubMed, EMBASE, Web of Science, and Cochrane Central from inception up to March 31, 2023. We included articles reporting accuracy values of CTA and/or CTP and compared the pooled sensitivity and specificity of both imaging methods using a random-effect model. We performed a subgroup analysis on the technique used in CTA and on the subtype of DMVOs (M2-only vs M2+other DMVOs). PROSPERO registration: CRD42022344006

Results We identified 12 studies encompassing 2607 patients, 479 (18.3%) with DMVOs. CTA had significantly lower sensitivity than CTP for detecting DMVOs [0.74, 95%CI (0.63–0.82) vs. 0.89, 0.95%CI (0.83–0.93), p<0.01]. When subgrouped into single-phase and multi-phase CTA, multi-phase CTA had significantly higher sensitivity for DMVO detection than single-phase CTA [0.91, 95%CI (0.85–0.94) vs. 0.64, 95%CI (0.56–0.71), p<0.01], while reaching similar levels to CTP [0.91, 95%CI (0.85–0.94) vs. 0.89, 0.95%CI (0.83–0.93) p=0.68]. The sensitivity of single-phase CTA greatly decreased when extending from M2 to other non-M2 DMVOs [0.74, 95%CI (0.63–0.83) vs. 0.61, 0.95%CI (0.53–0.68), p=0.02] which did not occur in CTP nor in multi-phase CTA. Specificity was high (>0.85) and comparable between all methods.

Conclusion CTP and multi-phase CTA are the preferred methods for DMVO screening due to their high accuracy.

Disclosure of Interest Nothing to disclose