Clinical evaluation of left ventricular function and morphology using an accelerated k-t sensitivity encoding method in cardiovascular magnetic resonance

Myocardial native T1 mapping at 3T cardiac magnetic resonance-closing the full-vendor reporting cycle of normal values

AIM

Cardiac magnetic resonance is currently an indispensable tool in the diagnosis of cardiac pathologies, with mapping techniques being one of the most recent advances in this area. T1 mapping is a robust tool that uses the T1 magnetic relaxation time as a quantitative marker of myocardial tissue composition. However, multiple T1 mapping sequences are used, and data comparing them, especially on different vendors, is limited. This study aims to determine the T1 relaxation values in the cardiac muscle of healthy individuals using GE's Discovery 3T scanner, allowing the use of the T1 mapping technique in patients on a sustained basis.

MATERIAL AND METHODS

Thirty-one healthy volunteers were submitted to T1 mapping at 3T magnetic resonance imaging (MRI) equipment, with 3 being excluded from the analysis (54% women; mean age: 39.2 ± 13.9 years). The MOLLI 5(3)3 sequence was used, acquiring one short axis slice at midventricular level. Native T1 values were presented as means (± standard deviation), and t-student independent samples tests evaluated gender differences in T1 values.

RESULTS

The results show an average global native T1 value of 1193 ± 39 ms, with women's values being statistically higher than men (1211 ± 40 vs 1173 ± 27 ms, respectively, p<0.006). Gender remained the only determinant of native T1 times on a multiple linear regression model that included age, ejection fraction, and T2 status.

CONCLUSION

This study has established one of the few native T1 values for a 3T GE Discovery scanner that are on par with those already reported by other vendors for a similar sequence, closing the circle in full-vendor reporting.

Reference Values of Native T1 at 3T Cardiac Magnetic Resonance-Standardization Considerations between Different Vendors

This study aimed at establishing native T1 reference values for a Canon Vantage Galan 3T system and comparing them with previously published values from different vendors. A total of 20 healthy volunteers (55% Women; 33.9 ± 11.1 years) underwent left ventricular T1 mapping at 3T MR. A MOLLI 5(3)3 sequence was used, acquiring three short-axis slices. Native T1 values are shown as means (±standard deviation) and Student’s independent samples t-test was used to test gender differences in T1 values. Pearson’s correlation coefficient analysis was used to compare two processes of T1 analysis. The results show a global native T1 mean value of 1124.9 ± 55.2 ms (exponential analysis), that of women being statistically higher than men (1163 ± 30.5 vs. 1077.9 ± 39.5 ms, respectively; p < 0.001). There were no specific tendencies for T1 times in different ventricular slices. We found a strong correlation (0.977, p < 0.001) with T1 times derived from parametric maps (1136.4 ± 60.2 ms). Native T1 reference values for a Canon 3T scanner were provided, and they are on par with those already reported from other vendors for a similar sequence. We also found a correlation between native T1 and gender, with higher values for women.