Ophthalmic artery arising from the presumed meningohypophyseal trunk of the cavernous internal carotid artery diagnosed by magnetic resonance angiography.

Abstract

The purpose of the study is to describe a case of ophthalmic artery (OA) arising from the presumed meningohypophyseal trunk (MHT) of the cavernous internal carotid artery (ICA). A 63-year-old woman suspected of having cerebral infarctions underwent cranial magnetic resonance (MR) imaging and MR angiography. MR angiography showed a right OA that was found to arise from the superolateral aspect of the proximal cavernous ICA. This OA entered the orbit via the superior orbital fissure (SOF). Rarely, an OA arises from the inferior aspect of the middle cavernous ICA at the level of the inferolateral trunk (ILT) and enters the orbit via the SOF. This OA variation was traditionally regarded as a persistent primitive dorsal OA but is now believed to be due to the persistence of the lateral branch of the primitive maxillary artery. The present case had an OA arising from the superolateral aspect of the more proximal cavernous ICA than the origin of the ILT, which was suggested to be the origin of the MHT. Persistence of the proximal segment of the trigeminal artery may play an important role in the formation of this extremely rare variation. To identify this extremely rare OA variation, careful observation of source images and the creation of volume-rendering MR angiography images are important.