Main Pulmonary Artery-to-Ascending Aorta Diameter Ratio in Healthy Children on MDCT

• Published in: American journal of roentgenology (1976) Vol. 205; no. 6; pp. 1322 - 1325
• Main Authors: Compton, Gregory L, Florence, Joshua, MacDonald, Cathy, Yoo, Shi-Joon, Humpl, Tilman, Manson, David
• Format: Journal Article
• Language: English
• Published: United States 01-12-2015
• Subjects: Adolescent; Aorta; Aortography - methods; Child; Child, Preschool; Female; Healthy Volunteers; Humans; Infant; Infant, Newborn; Male; Pulmonary Artery - diagnostic imaging; Retrospective Studies; Tomography, X-Ray Computed - methods; CT; pulmonary hypertension; pediatric
• ISSN: 0361-803X; 1546-3141
• DOI: 10.2214/AJR.15.14301

This study was performed to ascertain whether the adult ratio of 1:1 of the diameter of the main pulmonary artery (MPA) to the diameter of the ascending aorta (AA) (referred to hereafter as the MPA-to-AA ratio) on MDCT is applicable to children.
Our hypothesis, which is based on experiential observation, is that the MPA-to-AA ratio would be higher than 1 in healthy children. A retrospective analysis of vessel calibers in a population of children without pulmonary hypertension who had undergone MDCT was performed.
The MPA-to-AA ratio was statistically significantly higher in children of all ages than in adults. We would, therefore, submit that the normal MPA-to-AA ratio in children on MDCT is greater than 1 and closer to 1.09.
The demonstration of an MPA segment that is slightly larger than the AA in children undergoing MDCT should not suggest a diagnosis of pulmonary arterial hypertension.