Quantitative assessment of pure aortic valve regurgitation with dual-source CT

Abstract

Aim: To assess the severity of pure aortic regurgitation by measuring regurgitation volumes (RV) and fractions (RF) with dual-source computed tomography (DSCT) as compared to magnetic resonance imaging (MRI) and echocardiography.

Materials and methods: Thirty-eight patients (15 men, 23 women; mean age 46±11 years) with isolated aortic valve regurgitation underwent retrospectively electrocardiogram (ECG)-gated DSCT, echocardiography, and MRI. Stroke volumes of the left and right ventricles were measured at DSCT and MRI. Thus, RVs and RFs were calculated and compared. The agreement between DSCT and MRI was tested by intraclass correlation coefficient and Bland-Altman analyses. Spearman's rank order correlation and weighted κ tests were used for testing correlations of AR severity between DSCT results and corresponding echocardiographic grades.

Results: The RV and RF measured by DSCT were not significantly different from those measured using MRI (p=0.71 and 0.79). DSCT correlated well with MRI for the measurement of RV (r(I)=0.86, p<0.001) and calculation of the RF (r(I) =0.90, p<0.001). Good agreement between the techniques was obtained by using Bland-Altman analyses. The severity of regurgitation estimated by echocardiography correlated well with DSCT (r(s)=0.95, p<0.001) and MRI (r(s)=0.95, p<0.001). Inter-technique agreement between DSCT and two-dimensional transthoracic echocardiography (2DTTE) regarding the grading of the severity of AR was excellent (κ=0.90), and good agreement was also obtained between MRI and 2DTTE assessments of the severity of AR (κ=0.87).

Conclusion: DSCT using a volume approach can be used to quantitatively determine the severity of pure aortic regurgitation when compared with MRI and echocardiography.