CT Evaluation of Cavoatrial Junction for Optimal Placement of Central Venous Catheter in Infants

Purpose: To evaluate the location of and the most reliable radiographic landmarks of the cavoatrial junction (CAJ) for optimal placement of central venous catheter (CVC) in infants. Methods: CAJs were identified in infants that underwent a chest CT examination between June 2005 and October 2014, and distance between CAJ and thoracic inlet was measured using multiplanar CT images. Using CT images and a cross-reference scout radiography images, distance of designated radiographic landmarks of the CAJ from actual CAJ locations was measured and transformed into vertebral body units (VBUs; the distance between the inferior endplate of one vertebra and the inferior endplate of the next). Results: Of the 88 infants (boys=61, 69.3%), mean age was 4.9±3.4 months. Mean distance between CAJ and thoracic inlet was 42.3±9.7 mm. Vertical length of CAJ was found to be significantly associated with gender (P = 0.020) and age (6 months younger or older, P <0.001). Although carina was located far distal from CAJ (19.4±5.6 mm or 2.1±0.5 VBUs above CAJ), carina was visualized on the scout images in all patients. However, other landmarks (inflection of the right cardiac border, and the intersection between the bronchus intermedius and the right cardiac border) were not visualized on scout images in 40.9% and 37.5% of patients, respectively, because of a large thymus. Conclusions: Understanding of anatomical relationship and the most reliable radiographic landmarks of the CAJ enables optimal CVC positioning in infants.