[Magnetic Resonance Vessel Wall Imaging Reveals a Ruptured Blood Blister-like Aneurysm:A Case Report].

Recent advances in digital subtraction angiography(DSA)and 3D-CT angiography(3D-CTA)have enabled the identification of tiny intracranial aneurysms. However, the imaging of blood blister-like aneurysms(BBAs)in the internal carotid artery(ICA)is still challenging. We report the case of a subarachnoid hemorrhage(SAH)with a ruptured BBA in the ICA that was revealed by magnetic resonance vessel wall imaging(MR-VWI). A 68-year-old woman presented with SAH. CT showed diffuse SAH(Fisher group 3). 3D-CTA and DSA showed a small bulge in the right ICA. MR-VWI with gadolinium showed thick wall enhancement in the supraclinoid portion of the right ICA; hence, we diagnosed SAH because of the ruptured BBA of the right ICA. Trapping combined with high-flow bypass was performed for the ruptured BBA. We concluded that MR-VWI may be useful for diagnosing ruptured BBAs under strict blood pressure management.