Abstract:
In this paper, the Radial Strain (RS) and Strain Rate (SR) was calculated using tagged MRI (tMRI)
data. Using tagged magnetic resonance imaging (tMRI), the left ventricle short axis of five healthy
adults (three men and two women) and four healthy male rats was imaged during diastolic and
systolic phases on the mid-ventricle level. The RS and radial SR of the left ventricle were calculated
at the mid-ventricular level of the cardiac cycle. The peak RS for rat and human heart was
found to be 46.8 ± 0.68 and 40.7 ± 1.44, respectively, and it occurred at 40% of the cardiac cycle
for both human and rat hearts. The peak systolic and diastolic radial SR for human heart was 1.10
± 0.08 s−1 and −1.78 ± 0.02 s−1, respectively, while it was 4.25 ± 0.02 s−1 and −5.16 ± 0.23 s−1, respectively
for rat heart. The results show that tMRI data can be used to characterize the cardiac
function during systolic and diastolic phases of the cardiac cycle, and as a result, it can be used to
evaluate the cardiac motion by calculating its RS and radial SR at different locations of the cardiac
wall during both diastolic and systolic phases. This study also approves the validity of the tagged
MRI data to accurately describe the radial cardiac motion
