Bilateral Internal Carotid Aneurysms Presenting as a Nonpulsatile Parapharyngeal Mass: Complementary Diagnosis by CT, MR Imaging, and Digital Subtraction Angiography
Alberto Muñoz
,a,
Jorge Campolloa and
Joaqín Vergasa
a From the Section of Neuroradiology, Department of Radiology (A.M., J.C.) and Service of Otolaryngology (J.V.), Hospital Universitario "12 de Octubre", Madrid, Spain.
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FIG 1. Axial helical CT images without (A) and with (B) intravenous contrast material at the level of the oropharynx.
A, Note a well-defined isodense left mass (M), in the parapharyngeal space, with eggshell calcification abutting the oropharyngeal lumen. Another mass is also seen on the right side.
B, Central round vascular enhancement is seen in the arterial phase of contrast administration, consistent with the patent lumen of the aneurysm. There is also aneurysmal dilation of the right internal carotid artery and tortuosity and aneurysmal dilatation of the left vertebral artery (arrow)
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FIG 2. Axial MR images.
A and B, Axial T1-weighted (500/14 [TR/TE]), postcontrast fat-suppressed image (A), and T2-weighted fast spin-echo (4500/100) fat-suppressed image (B), at the same level. Notice lumen dilation with hyperintensity of both EICAs. The left is surrounded by a thick, low-signal rim, representing thrombus along the arterial wall.
C, MIP from TOF sequence source of images on coronal plane. Notice tortuosity of both EICAs above the carotid bifurcation with further fusiform aneurysmal dilation. Notice similar changes on the left vertebral artery. (Proximal portion of the common carotid artery is not seen because of the thickness of slice selected for MIP.)
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FIG 3. Digital subtraction angiography. Selective injection of the right common carotid artery (anteroposterior view), in the early arterial phase, shows tortuosity and fusiform aneurysmal dilation of the right EICA
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