Aortic root asymmetry in Marfan patients; evaluation by magnetic resonanceimaging and comparison with standard echocardiography

Background: Patients with Marfan syndrome may develop aortic root dissectio n despite only mild aortic root dilation as shown by standard echocardiogra phy, which may be due to aortic root asymmetry. Purpose of the present stud y was to investigate aortic root asymmetry by magnetic resonance (MR) imagi ng in patients with Marfan syndrome and to compare these measurements with standardly performed echocardiography. Methods: Eighty-seven Marfan patient s (mean age 31 +/- 8 years) underwent MR imaging. From this population, 15 patients (mean age 29 +/- 3 years) were selected in whom both echocardiogra phy and MR imaging had been performed within 3 months. With echocardiograph y, the aortic root was measured according to the recommendations of the Ame rican Society of Echocardiography. With MR imaging, a short axis view of th e aortic root was obtained to measure distances between the noncoronary, ri ght coronary and left coronary cusps and the aortic root area. Correlations between aortic root area and diameters were assessed, and 95% confidence i ntervals (95% CIs) calculated. Results: No difference in the standardly mea sured noncoronary to right coronary cusp diameter between MR imaging and ec hocardiography was shown (42 +/- 6 mm). Largest aortic root diameter on the MR images was the right to left coronary cusp diameter (46 +/- 7 mm, p < 0 .02). For a given noncoronary to right coronary cusp diameter, 95% confiden ce intervals revealed a variation of -20 to +20% in the aortic root area. C onclusions: The majority of Marfan patients show asymmetric dilation of the aortic root by MR imaging. This phenomenon may go unnoticed when standard echocardiography is performed. The asymmetry of the aortic root might be of clinical importance in unexpected aortic root dissection.