Assessment of right ventricular size and function: echo versus magnetic resonance imaging

The assessment of right ventricular (RV) size and function is important in the management of many patients with heart disease. Although magnetic resonance imaging (MRI) is considered the gold standard for quantitation of ventricular volumes and systolic function, subjective assessment ("eyeball") by echocardiography is the modality most often used for the RV. The echocardiographic "eyeball" method of assessing RV size and systolic function was compared with quantitative MRI.

Patients with right-sided congenital heart disease who underwent an echocardiogram within 6 months of MRI formed the study group. Four echocardiographers blinded to the MRI results reviewed the echocardiograms to subjectively assess RV size and systolic function. The reliability of an echocardiographer in accurately identifying a severely dilated RV and moderately to severely diminished RV systolic function was measured using the Kappa coefficient. Inter-rater agreement was also assessed using Kappa.

The study group consisted of 22 patients aged 16.6 +/- 7.1 years, with interval between MRI and echocardiogram of 49 +/- 54 days. Using echocardiography, reliability for accurately identifying a severely dilated RV was "slight" with a prevalence-adjusted bias-adjusted Kappa (PABAK) of 0.25; and for identifying moderately to severely diminished RV systolic function was fair with a PABAK of 0.43. Inter-rater agreement analysis was poor for both with Kappas of 0.07 (P = .22) and 0.12 (P = .09), respectively.

The usefulness of the echocardiographic "eyeball" method to estimate RV size and systolic function in patients with right heart disease has limitations when compared with MRI, specifically in regard to the variability between echocardiographers.