Diagnostic challenges with central venous catheter studies.

A central venous catheter is typically made of silicone rubber or polyurethane and inserted into a large central vein to provide prolonged and direct access to central venous circulation. These catheters provide a safe and effective method to administer intravenous medications, nutritional supplements, fluids and blood products. However, a myriad of complications is associated with central venous catheters, including, but not limited to, mechanical malfunction or fracture, kinking, erroneous placement, line infection, fibrin sheath formation and venous thrombosis. Following clinical and radiographic evaluation, contrast-enhanced line studies constitute the next best diagnostic tool to assess the functionality of central venous catheters. However, there is a lack of standardization in the literature outlining how these studies should be performed. In addition, the interpretation of these studies can be problematic for general pediatric radiologists, many of whom are often not familiar with placement or manipulation of these catheters. In this pictorial review, we highlight the challenges associated with performing and interpreting fluoroscopically guided contrast injection studies, using case studies drawn from a large tertiary children's hospital database for illustration. Revealing these challenges and understanding their causative mechanisms can improve the performance of these line studies.