Determining the normal size of the pediatric abdominal aorta in MRI.

Motivation: Reference values for the pediatric abdominal aorta based on MRI measurements remain unpublished. Goal(s): Establishing reference values for the diameter of the pediatric abdominal aorta using MRI. Approach: The abdominal aortic diameter of 151 cardiovascular-healthy children was measured at four levels by two radiologists using a stack-of-stars sequence after intravenous contrast. The obtained 3D-volume was used for the least squares regression model to relate aortic diameter to body surface area. Results: The interrater reliability of the aortic diameter measurements was excellent. The Akaike information criterion identified the natural logarithmic polynomial regression as the optimal model for relating aortic diameter to body surface area. Impact: Establishing reference values for the abdominal aorta in children is essential for the diagnosis and monitoring of cardiovascular disease.