Zur Y, Bosak E, Kaplan N
Elscint MRI Center, Haifa, Israel.
Magn Reson Med. 1997 May;37(5):716-22. doi: 10.1002/mrm.1910370513.
In this paper a new diffusion sensitive steady-state free precession (SSFP) pulse sequence with a reduced sensitivity to physiological brain motion is presented. The signal attenuation due to diffusion in this SSFP sequence is derived theoretically and confirmed experimentally with a phantom. It is shown that for brain tissue this signal attenuation is approximately independent of T1 and T2, but depends only on the pulse sequence used, i.e., the timing and the size of the RF and the gradient pulses. On this basis the diffusion constant can be calculated for any region in the image. Diffusion sensitive images of the brain obtained with our pulse sequence are presented and shown to be superior over an image obtained with a "conventional" diffusion sensitive SSFP sequence.
本文提出了一种对生理性脑运动敏感性降低的新型扩散敏感稳态自由进动（SSFP）脉冲序列。从理论上推导了该SSFP序列中由于扩散引起的信号衰减，并通过模型进行了实验验证。结果表明，对于脑组织，这种信号衰减近似与T1和T2无关，仅取决于所使用的脉冲序列，即射频脉冲和梯度脉冲的定时及大小。在此基础上，可以计算图像中任何区域的扩散常数。展示了用我们的脉冲序列获得的脑部扩散敏感图像，结果表明其优于用“传统”扩散敏感SSFP序列获得的图像。
