Abstract TP82: Long Distance of Delayed-Contrast Filling Sign on Four-Dimensional CT Angiography Associates With Cardiogenic Embolism

Abstract

Objectives: We hypothesized that the presence of delayed contrast filling sign (DCFS), which possibly reflected contrast penetration into the thrombus, was associated with stroke etiology with different clot component. We then aimed to evaluate its predictive value for stroke subtype in acute ischemic stroke (AIS) patients with M1 segment of MCA (MCA-M1) occlusion. Methods: We retrospectively included MCA-M1 occlusion patirnts who underwent CTP within 8 hours post-stroke onset. DCFS was defined as the presence of contrast diffusion through the thrombi after the arterial peak phase on 4D-CTA derived from CTP. We measured the straight distance from the origin site of MCA-M1 to the proximal occlusion site on the arterial peak phase (distance peak ), and the maximum distance among every continuous phase after the arterial peak phase (distance maximum ). We calculated the distance of DCFS as distance maximum -distance peak and investigated its value for predicting the stroke subtype. Results: Among 144 included patients, 80 were in cardiogenic embolism (CE) group, 31 in large artery atherosclerosis (LAA) group, and 33 in undetermined etiology (UE) group. The median distance of DCFS was 1.3mm, 0.4mm and 0.6mm in CE, LAA and UE groups, respectively. CE group had a longer distance of DCFS than LAA group ( p =0.001). The optimal cut-off value of distance of DCFS for predicting CE was 1.5mm. The sensitivity, specificity, positive predictive value and negative predictive value of a distance of DCFS>1.5mm for predicting CE were 55.0%, 87.1%, 90.0% and 38.0%. Moreover, a distance of DCFS>2.0mm had a specificity of 100% for predicting CE. Figure A-E shows a patient with DCFS>1.5mm, and Figure F-J shows a patient with DCFS<1.5mm. Conclusion: Long distance of DCFS was associated with cardiogenic embolism, which could provide clues of stroke etiology and help the pattern selection of reperfusion therapy in future.