Diagnostic Approach for Venous Thoracic Outlet Syndrome (VTOS)

Initial Diagnostic Evaluation

The American College of Radiology recommends duplex ultrasound as the first-line imaging test for VTOS due to its non-invasive nature, ability to perform dynamic maneuvers, and excellent evaluation of venous pathology 1, 2
Duplex ultrasound should be performed in both neutral position and with provocative maneuvers, looking for flow acceleration, turbulence, and arrest in signal propagation during maneuvers 1
Chest radiography is an important initial screening test to identify osseous abnormalities, including first rib anomalies, cervical ribs, congenital osseous malformations, and focal bone lesions 1, 4

Catheter venography is the gold standard for definitive diagnosis when intervention is being considered, and is performed with contrast injection during digital subtraction acquisition in both neutral and stressed positions 4, 5
CT Venography (CTV) is excellent for anatomical evaluation, and should be performed in neutral and elevated arm positions to evaluate for venous compression, thrombosis, and collateral circulation 5
MR Venography (MRV) has superior soft tissue contrast compared to CT, and should be performed in both neutral and arms-abducted positions to look for subclavian vein narrowing, occlusion, collateral formation, and thrombus 3, 6

Imaging findings must be interpreted in clinical context, as venous compression during arm abduction is common in asymptomatic individuals, with one study finding 71% of patients with unilateral venous compression had significant bilateral compression on imaging, but only 21% had bilateral symptoms 3
True VTOS is confirmed by finding venous thrombosis and collateral circulation in both neutral and stressed positions, representing objective findings of clinically significant venous compression 6
Deeper pathology such as Pancoast tumor or cervical spondylopathy should be considered, and additional imaging may be necessary 1

Postoperative venography is often indicated to evaluate for residual narrowing after surgical decompression 4
Follow-up imaging with ultrasound is useful for postoperative evaluation of vessel patency and complications 1