PULMONARY ARTERY AND AORTIC DIAMETERS;

MEASUREMENT WITH CALCULATION OF MAIN PULMONARY ARTERY TO ASCENDING AORTA RATIO IN HEALTHY CHILDREN, USING CT AS DIAGNOSTIC MODALITY

Abstract

Objectives: To measure pulmonary artery and aortic calibers, and calculating
main pulmonary artery to ascending aorta ratio in healthy children, to verify the adult ratio of
1:1. Study Design: Observational study. Place and duration of study: Radiology Department,
Combined Military Hospital, Peshawar from 15 July 2015 to 14 July 2016. Methodology:
Chest CT cans of 283 healthy children, with no history or predisposing causes of pulmonary
hypertension, performed between July 2015 and July 2016, were retrospectively studied.
Diameters of pulmonary artery and aorta were measured on CT chest, at the level of bifurcation
of the main pulmonary artery, and the ratio of pulmonary artery to ascending aorta was
calculated. Results: The average diameter of the main pulmonary artery, right pulmonary artery
and left pulmonary artery were 19 mm, 12.1 mm and 12.2 mm respectively. The diameter of the
ascending aorta was determined to be 12.2 mm and descending aorta was 13.67 mm. Ratio of
the main pulmonary artery to ascending aorta was 1.06, which was higher than the adult ration,
usually taken as <0.9. Conclusion: The measurement criteria devised for early detection of
pulmonary hypertension have different set of values when considering pediatric population as
compared to adults. Main pulmonary artery to ascending aorta ratio is significantly higher in
healthy children of all ages as compared to adults. CT scan is an excellent minimally invasive
modality in evaluation of the mediastinal vasculature.