Virtual arterial endoscopy as a diagnostic aid in a patient with basilar artery fenestration and thromboembolic pontine infarct

Abstract

Focal signal intensity loss of the basilar artery on MR angiograms obtained in a 69-year-old man was considered to be caused by an embolus, and thrombolytic therapy was initiated. On the follow-up MR angiograms, the same oval signal intensity loss of the basilar artery was observed. On the basis of a virtual endoscopic look into the basilar artery, the diagnosis of a rare vascular anomaly--a fenestration of the basilar artery--was confirmed and the presence of a thrombus at the site of the signal intensity loss was excluded.

Fig 1.

Images from the case of a 69-year-old man with acute pons infarction. A, Axial T2-weighted MR image reveals hyperintense signals in the left pontine area (arrowhead). Note the normal flow void in the middle cerebral and basilar arteries. B, Maximum intensity projection of the 3D time-of-flight MR angiogram shows a circumscript, small signal intensity loss of the basilar artery at its terminal segment (arrowhead).

Fig 2.

Virtual endoscopy (point of view is marked by green arrowhead in small black window) of the basilar artery shows an eight-shaped lumen due to incomplete fenestration (white arrowheads). Complete virtual endoscopic fly is available at www.ajnr.org.