Introduction Cerebral intraparenchymal hyperattenuation (IPH) is frequently recognized on computed tomography scans after mechanical thrombectomy (MT).

Aim of Study To evaluate IPH on flat-panel computed tomography (FPCT) findings and their clinical usefulness for predicting prognosis after successful MT for acute occlusion of anterior circulation.

Methods A retrospective review was conducted for 158 consecutive patients undergoing MT during the last six years. Immediate post-procedural IPH on FPCT was categorized into four patterns (none, striatal, cortical, or combined pattern). The existence of hemorrhagic transformation, intracerebral hemorrhage, and brain swelling was evaluated. Functional clinical outcomes were accessed with post-procedural 3-month modified Rankin scales (mRS).

Results Thirty-four patients were found to have IPH (16 striatal, 8 cortical, and 10 combined pattern). Hemorrhagic complication (P<0.001), brain swelling (P<0.001), and poor mRS scores (P=0.042) showed significant differences according to IPH patterns. Multivariate logistic regression analysis revealed that the presence of a striatal pattern (OR: 13.26, P<0.001), cortical pattern (OR: 11.61, P=0.009), and combined pattern (OR: 45.34, P<0.001) independently predicted hemorrhagic complications. The location of the occlusion (OR: 4.13, P=0.034), cortical pattern (OR: 5.94, P=0.039), and combined pattern (OR: 39.85, P=0.001) predicted brain swelling. Age (OR: 1.07, P=0.006) and the presence of a combined pattern (OR: 10.58, P=0.046) predicted poor clinical outcomes.

Conclusion FPCT is a rapid and effective tool for a prompt follow-up just after MT to predict prognosis. Cortical IPH patterns independently predicted a high rate of post-procedural hemorrhage or brain swelling. Combined pattern is a strong predictor for both radiologic and poor clinical outcomes.

Disclosure of Interest Nothing to disclose