Early diagnosis of cor pulmonale with MR imaging of the right ventricle.

Right ventricular (RV) wall volumes, chamber volumes, and RV ejection fractions were assessed by means of magnetic resonance (MR) imaging in 17 patients with moderate chronic obstructive lung disease and in 11 healthy subjects. Short-axis spin-echo or gradient-echo images encompassing the entire right ventricle were obtained. The mean RV wall mass in patients was significantly higher than that in healthy subjects (61 g +/- 13 [standard deviation] vs 47 g +/- 7, P = .005), while the ejection fraction was in the normal range in both groups. Interobserver agreement for measurements of both RV ejection fraction and RV wall mass was high (r = .91 for both). When a 60-g cutoff point was used to define RV hypertrophy, eight patients were considered to have cor pulmonale, which had been previously defined, on clinical grounds, in only five of these patients. It is concluded that detection of RV myocardial hypertrophy with MR imaging may aid in the early diagnosis of cor pulmonale complicating chronic obstructive lung disease.