The Relationship between Bleeding and Contrast Extravasation Judged by Dual Energy CT after Acute Thrombectomy

OBJECTIVE: There are many cases in which computed tomography (CT) after acute thrombectomy demonstrates high-density areas, but it may be difficult to judge whether this is hemorrhage or contrast extravasation. Dual energy CT (DECT) is an imaging method that enables discrimination of substances by acquiring X-ray image data of two different energies. METHODS: We performed DECT to distinguish hemorrhage from contrast extravasation in cases with high-density areas on CT after acute thrombectomy at our hospital, and we compared with T2*-weighted image on the following day. RESULTS: Six patients comprising 22 areas had high-density areas on CT after acute thrombectomy. In all, 20 of the 22 high-density areas were determined to be contrast extravasation by DECT, and no cases of subsequent symptomatic cerebral hemorrhage were observed. However, 11 areas with new microbleeds were confirmed in the 20 extravasation areas on MRI-T2* images the day after thrombectomy. CONCLUSION: This examination suggested that the contrast extravasation and its concentration are involved in the presence of low-intensity areas on T2*.