Jared Guthrie Cobb1, Cynthia B Paschal. 1. Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, USA. jared.g.cobb@vanderbilt.edu
Abstract
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 were 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.
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 were 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.
Authors: Warren D Foltz; Osama Al-Kwifi; Marshall S Sussman; Jeff A Stainsby; Graham A Wright Journal: Magn Reson Med Date: 2003-06 Impact factor: 4.668
Authors: Pippa Storey; Alexis A Thompson; Christine L Carqueville; John C Wood; R Andrew de Freitas; Cynthia K Rigsby Journal: J Magn Reson Imaging Date: 2007-03 Impact factor: 4.813
Authors: Taigang He; Peter D Gatehouse; Lisa J Anderson; Mark Tanner; Jennifer Keegan; Dudley J Pennell; David N Firmin Journal: J Magn Reson Imaging Date: 2006-09 Impact factor: 4.813