37 - CT Angiography of the Extremities

Summary

CT angiography (CTA) (1) and magnetic resonance angiography (MRA) are used instead of conventional angiography for many cases requiring evaluation of the blood vessels. Advantages of CTA compared with conventional angiography include the avoidance of arterial puncture, reduced radiation exposure, and reduced contrast load, with less resultant risk of renal toxicity (2). CTA is often more convenient for emergent evaluation because it does not require mobilization of the interventional radiography team. It is usually more readily available than MRA and avoids the monitoring limitations of the MRI suite. This chapter discusses the indications, diagnostic capabilities, and limitations of CTA of the upper and lower extremities, followed by images of important pathological findings.

INDICATIONS

CTA, like conventional angiography, should be performed after traumatic injuries in patients whose injured extremity is pulseless, has a neurological deficit, has an expanding hematoma, or has a bruit or thrill (3). It may also be required in penetrating trauma where the path of injury lies near an important vessel, with limb color or temperature change, or in blunt trauma with a suspicious mechanism, such as knee dislocations. Nontraumatic indications include patients who present with a cool, painful extremity suggestive of acute arterial insufficiency (4), or in suspected arteriovenous fistulas or aneurysms.