Which statement best identifies a definitive imaging approach for arterial TOS?

• A. Plain chest X-ray is sufficient
• B. Ultrasound alone provides definitive assessment
• C. CT and MRI offer definitive imaging
• D. Doppler alone confirms arterial compression

Answer: (C)

Definitive imaging for arterial TOS rests on detailed visualization of the subclavian artery and its relationship to surrounding structures. CT angiography or MR angiography provides high-resolution, three-dimensional images that show the artery as it courses under the clavicle and scalene muscles, pinpoint the exact site of compression, and reveal any complications like post-stenotic dilation or aneurysm. This level of anatomical and vascular detail is what makes CT or MRI the best choice for definitive assessment. Plain chest X-ray only outlines bones and cannot assess arterial compression. Ultrasound with Doppler can detect abnormal flow and suggest compression, but it’s limited by operator dependence and incomplete visualization of the thoracic inlet, so it isn’t definitive on its own. Doppler alone also lacks comprehensive anatomical context.