Preoperative Imaging and Testing of Jugular Foramen Tumors

Clinical suspicion of a jugular foramen tumor requires radiologic confirmation. Magnetic resonance imaging (MRI) most clearly defines the nature and extent of the lesion,66 and computed tomography (CT) may be warranted to further define the relevant osseous anatomy. Glomus tumors are generally described as heterogeneously enhancing lesions on gadolinium-enhanced MRI studies. Glomus tumors and meningiomas are typically described as causing irregular enlargement and erosion of the jugular foramen, whereas schwannomas expand the foramen with a smooth margin of bone erosion.

Bilateral carotid angiography is essential in the preoperative evaluation of glomus jugulare tumors to assess tumor vas-cularity and collateral cerebral blood flow and for consideration of possible preoperative intravascular embolization.67 Angiography of patients with glomus tumors demonstrates a marked vascular tumor blush with the primary blood supply derived from ascending pharyngeal and occipital artery branches of the external carotid artery. ICA cross-compression and intraluminal balloon occlusion combined with xenon perfusion scanning are useful in the evaluation of collateral blood supply if ICA sacrifice is anticipated. Evaluation of the venous phase of the angio-graphic study is recommended to determine the dominance of the transverse and sigmoid sinuses and to assess the degree of patency of the jugular bulb and internal jugular vein.

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