Abstract WP119: Magnetic Resonance Imaging versus Computed Tomography Before Mechanical Thrombectomy for Acute Ischemic Stroke

Abstract

Introduction: Magnetic resonance imaging (MRI) and computed tomography (CT) is useful for the evaluation of the ischemic core and penumbra. The indication for mechanical thrombectomy (MT) for acute ischemic stroke is determined by either or both imaging modalities. The selection of initial imaging modality is differed by the institute, and it is uncertain which imaging modality is superior before MT. In this study, we compared the clinical outcomes after MT by imaging modality in the K-NET registry (Kanagawa intravenous and endovascular treatment of acute ischemic stroke registry). Methods: The K-NET registry is a Japanese multicenter prospective registry study of patients treated with Intravenous thrombolysis with recombinant tissue plasminogen activator, endovascular treatment, or both for acute ischemic stroke. The present study is based on patients' data in the K-NET registry between January 2018 and June 2021. The inclusion criteria for the current analysis were as follows: (1) pre-modified Rankin score (mRS) 0-2; (2) patients transferred directly to primary stroke centers; (3) treated with MT; and (4) performed only CT or MRI for diagnosis of acute ischemic stroke before MT. The patients who performed both CT and MRI at admission were excluded. Unbalanced cohorts with a nonrandom distribution of patients were accounted for by using propensity score matching. Results: 2348 patients were enrolled in the registry during the period, and 753 patients were eligible for inclusion criteria. 498 (249 matched pairs) were included after propensity score-matched analysis. The baseline characteristics were well-balanced between the two groups. There was no difference in the final mTICI grade between the two groups. The time from image to puncture in the MRI group was significantly shorter than the CT group (52min versus 38min), and the time from image to recanalization was also significantly shorter in the MRI group (108min versus 88.5min). The rate of functional independence (90 days mRS 0-2) was higher in the MRI group versus the CT group (54.4% versus 43.8%, p=0.017). Conclusions: The selection of MRI before MT was associated with a shorter time from image to puncture and recanalization and a favorable outcome compared with CT.