High-resolution CT of the jugular foramen: anatomy and vascular variants and anomalies.

In high-resolution computed tomographic (HRCT) images of dry skulls and patients, the anatomy of the jugular foramen and its neighboring structures was demonstrated to excellent advantage. Among those structures visualized were the cortical margins of the jugular compartments, which are important in evaluating tumor involvement, the anatomic relationship between the jugular fossa and the hypotympanum, and the adjacent basal foramina. The inferior tympanic canaliculus, which transmits the inferior tympanic artery and nerve and houses one fifth of the glomus formation, thereby playing a role in arterial anomalies as well as glomus tumors, was occasionally recognizable. In addition, subtle bone findings associated with vascular anomalies in and around the jugular foramen, critically important in the differential diagnosis of glomus tumors, were visualized. Examples of these findings are presented.