To describe a case of short common trunk of the occipital artery (OA) and ascending pharyngeal artery (APA) arising from the internal carotid artery (ICA).

A 36-year-old woman with a history of surgical resection of a right lateral ventricular meningioma and atheromatous plaque of the right ICA underwent cranial magnetic resonance (MR) imaging and MR angiography of the head and neck region with a 3-Tesla scanner.

MR angiography of the neck region showed a small atheromatous plaque at the origin of the right ICA and an anomalous artery arising from the posteromedial aspect of the right ICA at the distal end of the carotid bulb. After creating partial volume-rendering (VR) images of the right carotid system, a short common trunk of the OA and APA arising from the ICA were clearly identified.

Using MR angiography, we report a case of a short common trunk of the OA and APA arising from the ICA. OA rarely arises from the ICA, while APA sometimes arises from both the ICA and the OA. APA arising from the OA can be regarded as having a long common trunk of the OA and APA. Only one case of a short common trunk has previously been reported using catheter angiography. This is the second case of this variation reported in the relevant English-language literature. Partial VR MR angiography images are useful for identifying small anomalous arteries located beside a large artery.