MR angiographyによる硬膜動静脈瘻の診断

Diagnosis for dural arteriovenous fistulas CDAVFs based upon MR angiography

I．はじめに

　MR angiography（MRA）は非侵襲的に脳血管を描出することが可能であり，現在では脳血管障害の日常診療におけるスクリーニング検査となってきた^5,6）．しかし，その撮影目的は脳動脈瘤の発見に重きを置くため，その関心領域は通常Willis動脈輪周辺に設定されることが多い．したがって横静脈洞・海綿静脈洞・錐体静脈洞などに病変が認められる，硬膜動静脈瘻のMRA所見についての報告は少ない^2,4,9）．今回われわれはMRAにより硬膜動静脈瘻を推定診断し，脳血管写で確定診断し得た2症例を経験したので報告する．

Diagnosis of dural arteriovenous fistulas (DAVFs) has been traditionally based on cerebral angiography, which is still an invasive process. Recent advances of MR angiography have started to bring us into a new area of diagnosis for stroke patients. While using MRA at the out-patient clinic for screening patients with cere-brovascular disease, we have had a chance to diagnose DAVFs. We discussed MRA findings concerning DAVFs, comparing them with the findings of conven-tional angiography. We also stressed the need to set the slab so as to include the entire posterior fossa in order to disclose any vascular anomaly around the lateral and sigmoid sinus.