The undulating line sign and other more common pediatric central catheter malpositions.

Central venous and arterial catheters are among the most commonly assessed support devices by radiologists. The position of these catheters must be carefully assessed to ensure proper placement, as malpositioning may lead to life-threatening consequences. Therefore, it is important for radiologists to understand the anatomy of the central vessels and the expected location of catheters. While this can be difficult in small children and especially in neonates, knowledge of the expected course and ideal termination of catheters allows for recognition of a malpositioned line, which may be unsuspected clinically. The purpose of this article is to discuss appropriate positioning of central catheters in pediatric patients, focusing primarily on venous catheters. We also propose a new radiographic sign to recognize, the undulating line sign, as an indication of an inappropriate course of a newly placed venous catheter.