Aneurysm of the azygos pericallosal artery: diagnosis by MR imaging and MR angiography.

Abstract

Summary: We present a case of an aneurysm of an azygos pericallosal artery diagnosed on conventional MR imaging and MR angiography, and confirmed with conventional angiography and at surgical exploration. Index terms: Arteries, Callosal (pericallosal); Aneurysm, mag-netic resonance The azygos pericallosal artery represents a rare anatomic variant where only a single enlarged pericallosal artery is present instead of the usual two. The azygos pericallosal artery divides in the region of the genu of the corpus callosum, send-ing out branches to supply the mesial surfaces of both cerebral hemispheres. Although rare, with a reported incidence of between 0.2 % and 4 % (1-3), its greatest significance rests in the high fre-quency of berry aneurysms noted to occur at its bifurcation. Case Report A 41-year-old woman with no significant history of past medical or psychological problems presented to medical attention complaining of a single episode of right body (face, arm, leg) weakness and numbness that lasted for 1 hr and then resolved. These symptoms may have been associated with an anxiety attack. At the time of her neurologic evaluation, her physical examination and labo-ratory blood analyses were noted to be unremarkable. The patient then underwent magnetic resonance (MR) imaging. MR imaging was carried out on a 1.5 T system (Mag-