Anatomia

The Jugular Foramen: A Review of Anatomy, Masses, and Imaging
Karen VincentP. BiagoAzzarelh RichardR. Smith, S. Caldemeyer, Mathews, MD MD MD MD

of lesions may occur in the jugular foramen, arising from the structures normally found within the jugular foramen or from contiguous structures. The most common jugular foramen lesions are nontumoral pseudolesions (eg, asymmetrically enlargedjugular foramen, high or protruding jugular bulb) and tumors (eg, paraganglioma, metastasis). In nontumoral pseudolesions, computed tomography (CT) demonstrates smooth, 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 and contrast enhancement at magnetic resonance (MR) imaging, thereby mimicking real disease. Use offlow-sensitive techniques or MR angiography will help clarify confusing cases. In cerebral venous thrombosis, CT findings are often normal. At conventional MR imaging, flow-related enhancement and in-plane, turbulent, or slow flow can cause loss of the flow void and thus mimic thrombosis. Consequently, phase-contrast MR venography is the imaging modality of choice in the assessment of cerebralvenous thrombosis. Most tumoral lesions of the jugular foramen manifest at CT as areas of infiltrative bone destruction, although schwannoma and meningioma cause smooth enlargement of the jugular foramen. In addition, most of these tumors have low to intermediate signal intensity on Ti-weighted MR images and intermediate to high signal intensity on T2-weighted MR images and enhance strongly after theadministration of contrast material. Careful analysis of these imaging features and correlation with clinical manifestations can allow a more specffic diagnosis.
A

variety

Index 127.36,

terms: 127.38

Foranien,

jugular,

127.3t).

127.92

#{149}

Skull,

base.

127.30,

127.92

#{149}

Skull,

primary

neoplasms.

127.32.

127.34,

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17: 1 1 23of Radiology.

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ogy, 1)ivision versitv Blvd. January RSNA, 9

of Neuropathology (BA.). Indianapolis. IN 46202-5253. 199”; acceptedJanuary

Indiana University School of Medicine, Received September 23. 1996; revisionreprint requests to K.S.C.

Hospital. December

13. Address

199”

1123

1.

2a. 1, 2. (1) Anatomic drawing of the jugular
,, .

Figures
foramen. ryngeal

petrosal sinus. (X1) nerves and vein (fr) traverse the pars vascularis. The Jacobson nerve (/) passes through the caroticojugular spine to the hypotympanum (H), and the Arnold nerve (A) passes through the mastoid to thedescending facial nerve canal (Vii). Glomus jugulare tumors of the temporal bone arise from paraganglionic tissue along these nerves. C = internal carotid artery, EAC = external auditory canal, MC = mandibular condyle. (2) Axial CT scans show the jugular foramen (JF) and adjacent structures such as the hypoglossal canal (HO, carotid artery, facial nerve, and petrooccipital fissure. CC carotid canal, SSsigmoid sinus.

The pars nerve (IX) The vagus (X) and the internal jugular

nervosa

contains

the glossopha-

and the inferior spinal accessory

=

=

U

INTRODUCTION differential diagnosis of a jugular foramen

2b. pathologic structures
or from

The
mass can

should arise
jugular

include the
foramen

processes normally
contiguous

that found
struc-

fromin

characteristics

(eg,

smooth

or infiltrative

tumor

the
tures. mally from
arise; sions

The contents of the jugular foramen norinclude portions of cranial nerves IX-XI, which neurofibroma or schwannoma can the jugular vein, from which pseudolesuch as a high or protruding jugular bulb,

margins, volvement, vascularity,
characteristics)

presence or absence of middle...