In vivo assessment of MR elastography-derived effective end-diastolic myocardial stiffness under different loading conditions

Purpose:

To compare magnetic resonance elastography (MRE) effective stiffness to end‐diastolic pressure at different loading conditions to demonstrate a relationship between myocardial MRE effective stiffness and end‐diastolic left ventricular (LV) pressure.

Materials and Methods:

MRE was performed on four pigs to measure the end‐diastolic effective stiffness under different loading conditions. End‐diastolic pressure was increased by infusing Dextran‐40 (20% of blood volume). For each infusion of Dextran‐40, end‐diastolic pressure was recorded and end‐diastolic effective stiffness was measured using MRE. In each pig, least‐square linear regression was performed to determine the correlation between end‐diastolic effective stiffness and end‐diastolic LV pressure.

Results:

A linear correlation was found between end‐diastolic LV pressure and end‐diastolic effective stiffness with R² ranging from 0.73–0.9. A linear correlation with R² = 0.26 was found between end‐diastolic LV pressure and end‐diastolic effective stiffness when pooling data points from all pigs.

Conclusion:

End‐diastolic effective myocardial stiffness increases linearly with end‐diastolic LV pressure. J. Magn. Reson. Imaging 2011;33:1224–1228. © 2011 Wiley‐Liss, Inc.