From the case: PICC line in left-sided SVC
DSA of thorax, venous injection from PICC
Frontal PICC line injected
Injection from the right subclavian vein shows contrast passing down a right mediastinal vein. The later runs show filling of the right atrium, proving that this is a right SVC which has an anomalous origin, rather than the azygos vein. A left SVC is also seen.