Objective To evaluate the value of cardiac MRI in the diagnosis of Ebstein anomaly (EA). Methods Twenty patients from February 2014 to April 2017 with EA confirmed by surgery were enrolled into this study. The analysis in all patients was made according to preoperative cardiac MRI, 2D TTE and surgical data, including the changes of tricuspid valve leaflets, Carpentier classification, the size and function of atrioventricle, late Gadolinium enhancement, the total right/left-volume index and cardiopulmonary bypass time,etc.The numbers of apicaldisplaced leaflets and development condition of all the leaflets were compared using the R×C χ2 among the three groups.With surgical results as the reference standard, the diagnostic accuracy of the two groups for the development condition of all the leaflets were evaluated. One-way ANOVA was performed to compare the differences of the apicaldisplaced distance of septal leaflet, using these three methods. Comparisons of the total right/left-volume index, surgery-related data between patients with or without late gadolinium enhancement were performed by independent t test. Results (1) The results in anatomicalstructures, such as distance of apicaldisplacedseptal leaflet, displacement of each leaflet and the Carpentier classification, showed nostatistical difference among MRI, 2D TTE and operational findings. The leaflet dysplasia defined by MRI and 2D TTE areequivalent to surgically defined severe dysplasia, and surgically defined mild to moderate dysplasia can't be identified by the former two methods. The overall diagnostic accuracy of MRI and 2D TTE to identify leaflet dysplasia were 41.3%(19/46) and 34.7%(16/46), respectively.(2) Functional right ventricular volume index decreased in 1 case, normal in 8 cases, increased in 11 cases;functional right ventricula rejection fraction decreased in 15 cases. Six patients' left ventricular volume index decreased, 13 remained in normal range, 1 showed increased;left ventricula rejection fraction decreased in 14 cases. (3)LGE was identified in 8 patients and non-LGE in 12. Difference of the total right/left-volume index [(7.12 ± 4.06) vs. (3.84 ± 2.10), P=0.029] between two groups was statistically significant. However, there was no statistical difference in extracorporeal circulation time, aorticcross-clamping time, intubation time, ICU residence time and postoperative hospital staybetween the LGE and non-LGE groups. Conclusions Cardiac MRI can relatively accurately evaluate the apicaldisplacement of leaflets and the morphological changes of the atria and ventricles, as well as quantitatively evaluate the ventricular function, which can provide references for clinical diagnosis and severity evaluation of EA. Key words: Ebstein anomaly; Magnetic resonance imaging; Anatomical structure; Ventricular function
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