Aortic Root Size by Echocardiogram Compared With Computed Tomography in Adolescents With Pectus Excavatum

Aortic root dilation is a risk factor for aneurysm and dissection. Echocardiography (echo) is the most frequently used initial screening method for the aortic root, but computed tomography (CT) is a preferred modality because of the ability to reformat the images and obtain measurements without the technical limits of echo image acquisition. There are limited data comparing the 2 modalities in measuring the aortic root.

This was a retrospective cohort study comparing echo with CT in measuring the aortic root and was conducted at a children's hospital. Forty adolescents (range, 10 to 18 y) with pectus excavatum were evaluated.

In the majority of patients (68%), echo underestimated the aortic root size compared with the CT measurement by at least 1 SD. The average difference between the 2 modalities was 2.5 mm. There was a trend for a greater difference between modalities as the aortic root increased. The severity of the deformity by Haller index did not correlate with greater underestimation of the aortic root size. The shape of the aortic root, ranging from circular to ovoid, also did not contribute to the underestimation of aortic root size by echo.

Echo can be used as a screening method for the aortic root, but it can underestimate the aortic root size when compared with CT measurements in pediatric patients with pectus excavatum. This difference was more profound as the diameter of the aortic root increased. Patients with dilated aortic roots on echocardiogram may benefit from biorthogonal measurements offered by other imaging modalities such as CT or magnetic resonance imaging.