Frontal branch of the left middle meningeal artery arising from the ophthalmic artery diagnosed by magnetic resonance angiography

A case of frontal branch of the left middle meningeal artery (MMA) arising from the ophthalmic artery (OA).

A 73-year-old woman with vertigo underwent cranial magnetic resonance (MR) imaging and cranial MR angiography using a 1.5-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.

MR imaging revealed multiple small ischemic white matter lesions. Maximum-intensity-projection (MIP) MR angiography showed no pathological arterial lesions such as steno-occlusive lesions; however, the left MMA arose from the OA. On MR angiographic source images, the tiny left MMA passed through the foramen spinosum and supplied the parieto-occipital trunk of the MMA. Thus, the left MMA arising from the OA was considered the frontal branch. The right MMA normally supplies both the frontal branch and the parieto-occipital trunk.

We present a case of MMA originating from the OA. The prevalence of this variation has been reported to be approximately 0.5%, which is not very rare. However, most reported cases are diagnosed using catheter angiography or cadaver dissection. We diagnosed this variation using MR angiography. Careful observation of MR angiographic source images is useful and important for identifying tiny arteries that cannot be visualized using MIP MR angiography.