破裂瘤の同定に造影MRIが有用であった多発性脳動脈瘤の1例

Magnetic Resonance Vessel Wall Imaging Reveals Rupture Site in Subarachnoid Hemorrhage with Multiple Cerebral Aneurysms

Ⅰ．はじめに

　くも膜下出血（SAH）において多発性動脈瘤を認める場合には，どの動脈瘤（An）が破裂瘤であるかを正確に診断することは治療方針や治療結果を左右するものであり，非常に重要である^4,6）．従来，その診断は脳血管撮影での動脈瘤の大きさや形状^5,10），頭部CTによる血腫分布など^1,2）を総合して推定されてきたが，その特定は必ずしも容易ではなく，ときに誤認する場合もあった^1,7,11）．今回，造影剤を用いたMR vessel wall imagingが破裂瘤の同定に有用であった多発性脳動脈瘤の1例を経験したので報告する．

　We report a case of subarachnoid hemorrhage（SAH）with multiple cerebral aneurysms, in which magnetic resonance vessel wall imaging（MR-VWI）revealed the rupture site. A 68-year-old woman presented with SAH. Computed tomography（CT）showed diffuse SAH（Fisher group 3). 3D-CT angiography revealed two intracranial aneurysms：a 4.2-mm anterior communicating artery aneurysm（Acom An）and a 5.8-mm basilar tip aneurysm（BAtip An). As the BAtip An was the larger of the two, it was deemed the most likely site of rupture；however, high-resolution MR-VWI with gadolinium showed thick wall enhancement in the Acom An and no enhancement in the BAtip An. Thus, we performed a craniotomy for the Acom An. Intraoperative findings confirmed the rupture site at the Acom An. We concluded that high resolution MR-VWI may be useful for identifying the rupture site in patients with spontaneous SAH and multiple cerebral aneurysms.