Assessment of aortic root dimensions in patients with suspected Marfan syndrome: intraindividual comparison of contrast-enhanced and non-contrast magnetic resonance angiography with echocardiography.

Purpose: Our purpose was to evaluate intraindividually the performance of contrast-enhanced magnetic resonance angiography (MRA) and non-contrast MRA for aortic root diameter measurements and to compare the results with routinely performed echocardiography in patients with suspected Marfan syndrome.

Methods And Materials: Aortic roots were examined prospectively in 51 consecutive patients with suspected Marfan syndrome by using contrast-enhanced MRA and non-contrast MRA at 1.5 T. Two readers independently measured aortic root diameters at the annulus, sinuses of Valsalva and sinutubular junction in both data sets and compared results with echocardiographic data. Intraclass correlation coefficient, Pearson correlation coefficient, Bland-Altman, and two-sided t-test were used to assess agreement between observers and methods.

Results: 38 (74.5%) of the 51 patients (25 female, 26 male; mean age 37.1 ± 13.7 years) had Marfan syndrome. Both, contrast-enhanced MRA and non-contrast MRA measurements of the sinuses of Valsalva revealed a strong correlation with echocardiography (r=0.850 and r=0.893, respectively). Intraclass correlation was markedly better for non-enhanced MRA (r=0.904) when compared to contrast-enhanced MRA (r=0.690). Image quality (p<0.001) as well as interobserver agreement (p<0.0042) of measurements of the sinuses of Valsalva was significantly better for non-enhanced MRA than for contrast-enhanced MRA.

Conclusion: Non-contrast MRA was more reliable and more valid than contrast-enhanced MRA for assessment of aortic root dimensions in patients with suspected Marfan syndrome. Therefore contrast agents can be omitted for establishing the diagnosis of aortic involvement in Marfan syndrome.