Measuring age-dependent myocardial stiffness across the cardiac cycle using MR elastography: A reproducibility study

Area of Science:

• Cardiovascular Imaging
• Biomechanical Engineering
• Medical Physics

Background:

• Assessing myocardial stiffness is crucial for understanding cardiac mechanics.
• Magnetic resonance elastography (MRE) offers a non-invasive method to quantify tissue stiffness.
• Reproducibility of cardiac MRE (CMRE) for myocardial stiffness measurement needs validation.

Purpose of the Study:

• To evaluate the reproducibility of measuring left ventricular (LV) myocardial stiffness using CMRE.
• To investigate the changes in myocardial stiffness throughout the cardiac cycle.
• To determine the correlation between myocardial stiffness and age.

Main Methods:

• Cardiac MRE (CMRE) was performed on 29 healthy volunteers (ages 21-73).
• Scans were repeated to assess inter-scan reproducibility of stiffness measurements.
• Myocardial stiffness was analyzed throughout the cardiac cycle and correlated with participant age.

Main Results:

• CMRE demonstrated good inter-scan reproducibility (concordance correlation coefficient rc = 0.77).
• Myocardial stiffness was significantly higher during end-systole (ES) than end-diastole (ED) in all subjects.
• Increased age correlated with a greater difference in stiffness between ES and ED.

Conclusions:

• CMRE is a reproducible technique for assessing LV myocardial stiffness.
• Myocardial stiffness exhibits cyclic variations, being higher in ES than ED.
• Age-related increases in ES stiffness contribute to a wider stiffness deviation between ES and ED.