Infant with catheter that infuses but does not draw back CXR from 2 weeks earlier (above) shows the tip of the catheter in appropriate position at the junction of the superior vena cava and the right atrium. Scout image from a line study (below) shows the tip of the catheter has migrated backwards in the interval and its tip now rests against the wall of the superior vena cava. The diagnosis was occlusion of the catheter tip due to catheter migration.