Primary thrombosis of right subclavian vein

MR venography shows the appearance of the subclavian veins in a 14-year-old girl following resolution of primary right upper extremity deep vein thrombosis with anticoagulation (A). With elevation of the extremities, dynamic MR venography demonstrated compression of subclavian veins bilaterally (B). After anticoagulation was discontinued, she presented with recurrent symptoms. Catheter-based venography showed chronic occlusion (C), and she underwent right first rib resection and open subclavian venoplasty, which resolved her symptoms.