A 17-year-old male, who was involved in a baseball club, presented to our emergency department with the complaint of gradual onset of swelling of his right arm. Contrast-enhanced computed tomography showed obstruction of the proximal portion of the right subclavian vein and pulmonary thromboembolism. Venography confirmed an occluded right subclavian vein. The patient was diagnosed with right subclavian vein thrombosis, which is referred to as Paget-Schroetter syndrome (PSS). An ultrasonography for the affected subclavian vein was helpful not only for making an accurate diagnosis of PSS, but also for verifying dynamic venous flow changes depending on the forearm position. <Learning Objective: This paper aims to describe the usefulness of ultrasonography. A 17-year-old male was diagnosed with Paget-Schroetter syndrome (PSS). In this case, we found ultrasonography is important for verifying dynamic venous flow changes depending on the forearm position. Holding the forearm in a pronated and downward position may have been critical for maintaining good venous flow with prompt resolution of symptoms. Ultrasonography may play a crucial role in assessing an appropriate treatment strategy for PSS.>.
Keywords: Paget-Schroetter syndrome; Pulmonary thromboembolism; Ultrasonography; Upper extremity deep venous thrombosis.