Pulmonary transit time from contrast echocardiography and cardiac magnetic resonance imaging: Comparison between modalities and the impact of region of interest characteristics.

Contrast echocardiography underestimates transit time measurements obtained by cardiac MRI, although the discrepancy was systematic and may have been contributed to by the interval between imaging studies. ROI location and size did not impact transit time values, suggesting that ROIs could be placed without intensive training, a step toward incorporation of real-time PTT measurement into echocardiographic laboratory workflow.