WORKUP Being vascular lesions, once a pulsatile nature is confirmed by physical exam, needle biopsy is frowned upon. Instead, imaging studies are recommended, beginning with a contrastenhanced neck computed tomography (CT) scan or magnetic resonance imaging (MRI). CT imaging will show a lesion that splays the internal and external carotid arteries and carries a “salt/pepper” appearance (Figure 3.1). Once the diagnosis is suspected, a vascular
study such as MRA or formal angiography is recommended to confirm the diagnosis. A characteristic blush is noted on angiography, and not tissue sampling is needed to proceed with treatment (Figure 3.2).