Improved In Vivo Measurement of Myocardial Transverse Relaxation With 3 Tesla Magnetic Resonance Imaging

Purpose: To develop practical methods at 3 Tesla (T) for measuring myocardial transverse relaxation in normal human myocardium. Materials and Methods: Ten healthy volunteers were investigated with four multi-echo, turbo spin-echo (TSE) methods. Each method traded acquired phase encoding lines per image for echo-image sample points obtained along the T(2) decay curve. Four multi-echo turbo field-echo (TFE) methods we're also tested. The TFE methods highlighted differences between achievable receiver bandwidth and echo time constraints versus the number of sample points obtained along the T(2)* decay curve. Results: Measured transverse relaxation values were consistent in reported means across all scan methods. T(2) for the ventricular septum was measured as 58.8 +/- 7.7 ms (N = 10). T(2)* for the ventricular septum was 31.6 +/- 5.8 ms (N = 10). The variation of mean T(2) or T(2)* within an region of interest improved significantly with increases in acquired echoes. Therefore, four or more echoes may provide for clear distinctions between regions of altered tissue composition within a subject. Conclusion: These results suggest that the 4-echo methods are best suited for measuring variations in transverse relaxation values in the mid-ventricular septum.