Unusual misplacement of a subclavian vein catheter detected on a bone scan.

An ill woman with history of lymphoma and heart failure presented with back pain and was referred for a bone scan. Presence of the diffuse superficial phlebitis made the superficial venipunctures difficult and therefore the radiotracer [740 MBq Tc-MDP] was injected via the indwelling central venous catheter inserted in the right subclavian vein. Three hours later, static imaging (fig. 1) revealed unexpected radiotracer accumulation in the liver. Although misplacement of subclavian catheters into the inferior vena cava (IVC) have been widely appreciated, however, this unusual pattern indicative of catheter entrance into the hepatic vein and retrograde distribution of radiotracer into the liver parenchyma has not been reported. This accidental finding promoted us to suggest that as an alternative approach to the commonly-used post-insertion radiological control of catheters, it can be possible to control the proper localization of the various internal catheters with the injection of small doses of readily available radiotracers (e.g. Tc-pertechnetate).