CT scan thoracic outlet syndrome

A 25-year-old female presented with a pulsatile left supraclavicular mass. A CT scan reformatted in the coronal view shows an oblique band of tissue (arrow) impinging on and compressing the subclavian artery resulting in post-stenotic dilation of the artery (arrowhead). The dilated segment of the subclavian artery correlated with the pulsatile mass noted clinically.