THE JUGULAR FORAMEN - A REVIEW OF ANATOMY, MASSES, AND IMAGING CHARACTERISTICS

A variety of lesions may occur in the jugular foramen, arising from th e structures normally found within the jugular foramen or from contigu ous structures. The most common jugular foramen lesions are nontumoral pseudolesions (eg, asymmetrically enlarged jugular foramen, high or p rotruding jugular bulb) and tumors leg, paraganglioma, metastasis), In nontumoral pseudolesions, computed tomography (CT) demonstrates smoot h, intact margins of the jugular foramen, Turbulent or slow flow in a high or protruding jugular bulb can result in loss of the flow void an d contrast enhancement at magnetic resonance (MR) imaging, thereby mim icking, real disease, Use of flow-sensitive techniques or MR angiograp hy will help clarify confusing cases, In cerebral venous thrombosis, C T findings are often normal, At conventional MR imaging, flow-related enhancement and in-plane, turbulent, or slow flow can cause loss of th e flow void and thus mimic thrombosis, Consequently, phase-contrast MR venography is the imaging modality of choice in the assessment of cer ebral venous thrombosis, Most tumoral lesions of the jugular foramen m anifest at CT as areas of infiltrative bone destruction, although schw annoma and meningioma cause smooth enlargement of the jugular foramen, In addition, most of these tumors have low to intermediate signal int ensity on T1-weighted MR images and intermediate to high signal intens ity on T2-weighted MR images and enhance strongly after the administra tion of contrast material, Careful analysis of these imaging features and correlation with clinical manifestations can allow a more specific diagnosis.