Appropriate imaging before carotid endarterectomy.

The question of which imaging method to use before performing carotid endarterectomy is a common and practical issue confronted by vascular surgeons. The imaging modalities of duplex ultrasonography, angiography, computed tomography (CT) and magnetic resonance angiography (MRA) have all been used in the preoperative assessment of the patient scheduled for carotid endarterectomy. This article focuses on these 4 modalities, with particular emphasis on the advantages and disadvantages of duplex ultrasonography versus angiography. The emergence of duplex ultrasonography as the sole preoperative imaging test has generated controversy among vascular surgeons and other specialists who deal with patients with carotid artery disease. Angiography, which has been the "gold standard" imaging test in the past and has been the reference standard in the large, randomized controlled trials, imposes a small but definite risk of stroke and death. Duplex ultrasonography can be used as the sole preoperative imaging test on a selective basis, provided that there is institutional validation and ongoing quality assurance. Although MRA is not widely available, the combination of MRA and duplex ultrasonography can provide similar diagnostic accuracy to angiography in some institutions. Routine CT appears to be unnecessary but is useful in certain circumstances.