Dissecting aneurysm of the anterior choroidal artery: angiographical and MR imaging findings

BACKGROUND: Intracranial dissecting aneurysms are relatively rare. We present a rare case of a dissecting aneurysm originating from the anterior choroidal artery; this is the first reported case.CASE DESCRIPTION: A 42-year-old man suffered sudden onset of right hemiparesis and dysarthria. Computed tomography on admission revealed a small low density area in the posterior limb of the internal capsule. MR imaging revealed aneurysmal dilatation of the anterior choroidal artery, and angiography revealed aneurysmal dilatation and stasis of dye in the venous phase at the anterior choroidal artery, which resolved in the chronic stage.CONCLUSION: We describe a rare case of a dissecting aneurysm of the anterior choroidal artery. The radiological findings were characteristic of dissecting aneurysms in spite of the rare location.