Pike G B
McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada.
Magn Reson Med. 1996 Jul;36(1):95-103. doi: 10.1002/mrm.1910360117.
Magnetization transfer (MT) imaging with a rapid gradient-echo sequence and pulsed saturation provides an efficient means of acquiring high resolution three-dimensional data in vivo. This paper presents a derivation of the theoretical steady-state signal equation for this sequence based on the two-site coupled Bloch equations. Numerical simulations are used to validate the derived expression and experiments are performed on an agar gel model and normal brain. Experimental agar data indicate that direct saturation of the liquid component can be a major source of signal attenuation whereas MT normally dominates in brain tissue. The signal equation presented here establishes the necessary theory for sequence design and optimization and provides insight into model parameters and experimental results.
使用快速梯度回波序列和脉冲饱和的磁化传递（MT）成像提供了一种在体内获取高分辨率三维数据的有效方法。本文基于两点耦合布洛赫方程推导了该序列的理论稳态信号方程。通过数值模拟验证推导表达式，并在琼脂凝胶模型和正常脑组织上进行实验。实验琼脂数据表明，液体成分的直接饱和可能是信号衰减的主要来源，而MT在脑组织中通常占主导地位。本文提出的信号方程为序列设计和优化建立了必要的理论，并为模型参数和实验结果提供了深入见解。
