Quantification of Aortic Regurgitant Fraction and Volume with Multi-detector Computed Tomography: Comparison with Echocardiography

Rationale and Objectives: Evaluate quantification of the aortic regurgitant fraction and volume with computed tomography (CT). Materials and Methods: Fifty-three patients with aortic regurgitation (AR) and 29 controls were examined with 64-multi-detector CT coronary angiography and transthoracic echocardiography CITE). A dedicated software algorithm employing three-dimensional segmentation of left ventricle (LV) and right ventricle (RV) volumes and LV mass was applied. AR volume and fraction was calculated based on RV and LV stroke volumes (SV) and compared with echocardiography. The aortic regurgitant orifice area (ROA) was measured by CT. Results: A good correlation of the AR fraction and AR volume determined by CT compared to echocardiography was found for mild, moderate, and severe AR with 14.2% +/- 9, 28.8% +/- 8, and 57.9% +/- 9 (r = 0.95, P < .001) for AR fraction, and 15.7 mL +/- 11.33 mL +/- 14, and 98.9 mL +/- 36 for AR volume (r = 0.92, P < .0001), respectively. CT correctly classified severity of AR in 93% of patients based of AR-fraction, and in 89% based on AR volume. The sensitivity and specificity of CT were 98% and specificity 90.3%. The specificity improved to 97%, if the ROA by CT was added as diagnostic criterion. Conclusion: Aortic regurgitation fraction and volume can be accurately quantified from CT coronary angiography datasets. These parameters can assist clinical management, e.g. in case of pending cardiac surgery decision.