Comparative assessment of ascending aortic aneurysms in Marfan patients using ECG-gated computerized tomographic angiography versus trans-thoracic echocardiography.

Background: Contrast-enhanced computed tomography (CT) is routinely used as a complementary technique to trans-thoracic echocardiography (TTE) for assessing thoracic aortic aneurysms (TAA). However different measures can be obtained on CT and there are no recommendations on which to use. The objective was to determine which CT measurements most closely match reference TTE measurements in Marfan patients with TAA.

Methods: TTE measurements were obtained using the leading edge-to-leading edge technique in end-diastole on the parasternal longitudinal view. ECG-gated CT measurements were obtained, using the inner-to-inner technique in end-diastole by double oblique reconstruction: on three-cavity view (3C), left ventricle-aorta view (LVAo), and strict transverse plane passing through the maximal diameter "cusp to commissure" and "cusp to cusp" for each cusp. CT and TTE were performed within one month.

Results: 44 Marfan patients (39 ± 19 years, 48% men) were included. Dilatation of the ascending aorta was maximal at the level of the sinuses (TTE diameters: mean 47.5 ± 5.3 mm). TTE diameters were similar to 3C, LVAo (mean differences: 2.2 and -0.1 mm, p=NS) and to the three "cusp to cusp" diameters (mean differences ranging from 0 to 1.1mm, p=NS), whereas "cusp to commissure" diameters were all statistically smaller than TTE (3.6 mm, 2.9 mm and 3.7 mm, p ≤ 0.01).

Conclusions: Inner-to-inner "cusp to cusp" diameter measured on an ECG-gated CT should be used for comparison with 2D TTE aortic diameter at the level of the sinuses of Valsalva in patients with thoracic aortic aneurysms.