Preschooler with a catheter that does not draw back

Line study of an occluded central venous catheter due to migration
CXR from 3 months before (above) shows the tip of the catheter in appropriate position in the superior vena cava. Scout image from the line study (below) shows interval migration of the tip of the catheter so that its tip now lies nearly flush against the lateral wall of the superior vena cava.

The diagnosis was occlusion of the catheter tip due to catheter migration.