Effect of Driver Material Properties and Excitation Frequencies on Quantitative Myocardial Stiffness Measurements in Magnetic Resonance Elastography

ABSTRACT Background Myocardial stiffness is a crucial indicator of cardiac function and is associated with various cardiovascular diseases. Magnetic resonance elastography (MRE) is a noninvasive imaging technique used to measure myocardial stiffness. However, the effects of driver material properties and excitation frequencies on MRE performance remain unclear. This study investigated the influence of different driver materials and excitation frequencies on myocardial stiffness measurements and signal quality. Methods This prospective study included 13 healthy adults (four women and nine men) without known cardiac disease. MRE was performed on a 3.0‐T magnetic resonance imaging system using two different driver materials (flexible and rigid) at two frequencies (80 and 140 Hz). Myocardial stiffness and octahedral shear strain signal‐to‐noise ratio (OSS‐SNR) were quantified. Paired t ‐test, intraclass correlation coefficient, and Bland–Altman analysis were used for statistical analysis. Results At 80 Hz, the flexible driver yielded significantly higher stiffness values and OSS‐SNR than the rigid driver (all p < 0.01). At 140 Hz, the two drivers resulted in similar stiffness values; however, the rigid driver yielded a significantly higher OSS‐SNR ( p = 0.007). A significant increase in stiffness was observed at 140 Hz compared with that at 80 Hz ( p < 0.001). Conclusions Owing to its superior signal quality, the flexible driver may be more suitable for low‐frequency (80 Hz) MRE. Meanwhile, the rigid driver may exhibit better performance at higher frequencies (140 Hz). Appropriate matching of driver materials and frequencies may help optimize wave field quality, thereby providing more reliable myocardial stiffness estimates.