Comparison of myelin water fraction from multiecho T2decay curve and steady-state methods

摘要: Purpose Myelin water fraction is conventionally measured from the T2 decay curve. Recently, a steady-state approach entitled multicomponent-driven equilibrium single pulse observation of T1/T2 (mcDESPOT) was employed for myelin mapping. However, no direct comparison between established multiecho relaxation method and mcDESPOT has been performed. Methods Gradient spin echo (GRASE) acquired curve measurements were 10 healthy volunteers using 3T MRI. We compared fraction, transmit radio frequency field (B1), T2's intra- extracellular obtained both methods. Results For all brain regions examined, fractions significantly higher than those GRASE. B1 maps qualitatively similar GRASE mcDESPOT, but multicomponent times different. To investigate effect exchange, data analyzed with without exchange. When exchange turned off, roughly consistent results; however, derived still GRASE. Conclusion Myelin values cannot be considered to equivalent approaches. Magn Reson Med 73:223–232, 2015. © 2014 Wiley Periodicals, Inc.