Meara Simon J P, Barker Gareth J
Imaging Science and Biomedical Engineering Research Group, University of Manchester, Manchester, United Kingdom.
Magn Reson Med. 2007 Oct;58(4):825-9. doi: 10.1002/mrm.21338.
Multislice MR images obtained using a fast spin-echo (FSE) readout are strongly affected by magnetization transfer (MT) effects, which will cause a decrease in the observed longitudinal relaxation times for tissues with a large bound water component. This is pertinent for FSE-based inversion-recovery (IR) sequences, as it would be expected to cause a change in the required inversion times. Furthermore, the effect will be greater as the number of slices that are acquired within the repetition time (TR) is increased. A pseudo-3D IR-FSE sequence was used to obtain images of a phantom consisting of thermally crosslinked bovine serum albumin. It was found that increasing the number of slabs acquired per TR period led to a decrease in the inversion time that maximally suppressed the signal from the MT phantom; this was not the case for water. This has important consequences for any IR imaging sequence that uses an FSE readout.
使用快速自旋回波（FSE）读出方式获得的多层磁共振图像会受到磁化传递（MT）效应的强烈影响，这将导致具有大量结合水成分的组织的观测纵向弛豫时间缩短。这对于基于FSE的反转恢复（IR）序列而言至关重要，因为预计会导致所需反转时间发生变化。此外，随着在重复时间（TR）内采集的层数增加，这种效应会更大。使用伪三维IR-FSE序列来获取由热交联牛血清白蛋白组成的模型的图像。结果发现，每个TR周期采集的板层数增加会导致最大程度抑制来自MT模型信号的反转时间缩短；而对于水则并非如此。这对于任何使用FSE读出方式的IR成像序列都具有重要影响。
