Multimodality comparison of quantitative volumetric analysis of the right ventricle

Real-time 3D echocardiography (RT3DE), cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) can quantify right ventricular (RV) volume and overcome the limitations 2D echocardiography that stem from the unique geometry of the right ventricle. We tested a new technique for volumetric analysis of the right ventricle designed for RT3DE, CMR and CCT (TomTec) on images obtained in RV-shaped phantoms and in 28 patients with a range of RV geometry who underwent RT3DE, CMR and CCT imaging on the same day. In-vitro measurements showed that: (1) volumetric analysis of CMR images yielded the most accurate measurements; (2) CCT measurements showed slight (4%) but consistent overestimation; (3) RT3DE measurements showed small underestimation, but considerably wider margins of error. In patients, both RT3DE and CCT measurements correlated highly with the CMR reference (r-values 0.79-0.89) and showed the same trends noted in-vitro. In conclusion, eliminating analysis-related inter-modality differences allowed fare comparisons and highlighted the unique limitations of each modality. Understanding these differences promises to aid in the functional assessment of the right ventricle.