Abstract
Purpose
To assess the accuracy of several noninvasive MRIโbased estimators of pulmonary artery pressure by comparing them with invasive pressure measurement.
Materials and Methods
We compared five MRI methods with invasive pressure measurement by catheterization, in one group of pulmonary hypertension (PH) patients. Doppler echocardiography was included as a reference method. Main inclusion criterion was a mean pulmonary artery pressure above 25 mmHg at catheterization. MRI velocity quantification was used to obtain pulmonary flow acceleration and ejection times, and pulse wave velocity. The ventricular mass index was also assessed on MRI. Two commercially available 1.5โT systems were used for this study.
Results
Data from 44 patients were analyzed. Correlation of acceleration time with mean pressure was: r = โ0.21, P = 0.21, correlation of the acceleration/ejection time ratio with systolic pressure was: r = โ0.26, P = 0.01. The ventricular mass index showed the best correlation with mean pressure, with r = 0.56, P < 0.001. Using the pulse wave velocity and the crossโsectional area of the pulmonary artery, the mean pressure could not be estimated accurately.
Conclusion
Accurate estimation of pulmonary artery pressure in PH patients was not feasible by the MRI estimators studied. These noninvasive methods cannot replace right heart catheterization at this moment. J. Magn. Reson. Imaging 2005;22:67โ72. ยฉ 2005 WileyโLiss, Inc.