In a clavicle fracture with bruit and suspected vascular injury, which imaging study best evaluates the vascular injury?

• A. MRI angiography
• B. CT angiography
• C. Doppler ultrasound
• D. Plain CT

Answer: (B)

In this scenario the main concern is vascular injury to the subclavian/axillary vessels after a clavicle fracture, suggested by the presence of a bruit. The best imaging study to evaluate such vascular injury is CT angiography. It quickly provides detailed visualization of the arterial lumen from the neck through the chest and upper extremity, allowing detection of occlusion, dissection, pseudoaneurysm, active bleeding, or a vascular fistula. It also maps the relationship between the fracture fragments and the vessels to guide management and planning for possible endovascular or surgical intervention.

Doppler ultrasound, while useful for peripheral vessels, has limited ability to assess the proximal thoracic inlet vessels and is highly operator-dependent, making it less reliable for subclavian/axillary injuries. MRI angiography avoids radiation and iodinated contrast but is slower, less available emergently, and can be impractical in acutely injured patients. Plain CT shows bone and soft tissue but cannot adequately evaluate the vessel lumen for injury.