Quantification of Single Valve Regurgitation in the Pediatric Population Using 3-Dimensional Echocardiography: Reproducibility and Comparison with Cardiac Magnetic Resonance Imaging

Quantification of the regurgitation fraction (RF) in pediatric patients requires cardiac magnetic resonance imaging (CMR). Three-dimensional echocardiography (3DE) can be used to measure right and left ventricular volumes and therefore has the potential to calculate the RF by comparison of stroke volumes. 3DE volume acquisitions can be acquired in only a few heartbeats, often as part of a standard pediatric study. This study compared the quantification of single valve regurgitation by 3DE with CMR, the latter serving as the gold standard. Patients < 18 years of age were included in the study if they had mild regurgitation of one valve and a biventricular circulation. Patients were excluded if they had more than mild regurgitation of another valve, or a significant shunt lesion. Full right and left ventricular volume data sets were obtained using a Philips -iE33 or EPIQ CVx machine (X5 or X7 ultrasound probe) as a part of studies done for clinical reasons. 3DE volumes and RFs were analyzed retrospectively by blinded echocardiographers using 4D Cardioview (Tomtec Imaging Systems) and compared with ventricular volumes and RF obtained by CMR. Additionally, 3DE-derived ventricular volume ratios (VVR) were analyzed for correlation and agreement with CMR. Inter- and intra-observer reliability were assessed for 3DE ventricular volumes and RF. 43 patients were included with 7 patients having two separate paired 3DE and CMR studies. The median patient age was 8.4 (IQR; 3.6–12.0) years. Anesthesia, for the CMR study, was used for 20 (40%) of the paired studies. Valve involvement was: mitral-18 (33%), tricuspid-12 (22%), pulmonary-5 (9%), and aortic-20 (36%). Agreement between 3DE and CMR ventricular volumes as well as 3DE and CMR VVR was excellent, with good agreement for the regurgitation fraction across the two modalities. 3DE compared well with CMR in delineation of severity of regurgitation (mild, moderate, and severe). Intra- and inter-observer reliability was excellent for ventricular volumes, VVR, and RF. Quantitative assessment of single valve regurgitation using 3DE compared well with CMR in pediatric patients. Ventricular volume ratios obtained using 3DE strongly correlated with CMR. The short time for image acquisition, lower cost, and relative ease of acquisition should allow for application of 3DE to quantify single valve regurgitation in this population and will be useful for interpretation of serial studies.