Cardiac cine MRI: Quantification of the relationship between fast gradient echo and steady-state free precession for determination of myocardial mass and volumes

Purpose: To determine the correlation function between the steady-state free precession (SSFP) and fast gradient echo (FGRE) cine MRI pulse sequences for measuring the myocardial mass and volumes. Materials and Methods: Cardiac cine MRI examinations were acquired in 50 individuals (female: 35, male: 15, mean age 64.1 ± 9.1 years, range 48-83) using SSFP and FGRE cardiac pulse sequences. Results: The mean (standard deviation [SD]) left ventricular end diastolic volume measured by SSFP was significantly larger (4.5%) than by FGRE (P < 0.001); this was also the case for end systolic volume (15.0%, P < 0.001). The relationship between SSFP and FGRE measures were linear and highly correlated (P < 0.001) for both left ventricular end diastolic and end systolic volumes (r² = 0.90 vs. 0.91, respectively). We determined linear regression models to estimate the SSFP values based on the FGRE measures. Slope (intercept) for ejection fraction, stroke volume, and cardiac output were 0.99 (-2.79), 0.77 (17.5), and 0.76 (1.29), respectively. Conclusion: Linear relationships exist for key LV function parameters when comparing SSFP and FGRE cine MRI. These results indicate that existing databases and normal values for FGRE LV function may be converted to corresponding LV function values for SSFP MRI.