The aim of the study was to assess the usefulness of a novel contrast agent in combination with three-dimensional echocardiography for improved mass quantification. Three-dimensional reconstruction of left ventricular myocardium was performed from images obtained with rotational epicardial acquisition in eight open-chested pigs, before and after injection of a deposit contrast agent, Quantison Depot. Three-dimensional echocardiographic myocardial mass values were in excellent agreement with weighted mass (differences -1.6 +/- 5.0 g for end-diastolic frame, -2.8 +/- 4.5 g for end-systolic, 1.0 +/- 1.0 g for end-diastolic with contrast and 0.6 +/- 2.0 g for end-systolic with contrast, p = NS). Left ventricular mass measurements after contrast injection were more accurate and had less measurement variability. In conclusion, myocardial contrast enhancement improves left ventricular mass calculation with three-dimensional echocardiography.