Kyathanahally S P, Fichtner N D, Adalid V, Kreis R
Department of Clinical Research and Institute of Diagnostic, Interventional and Pediatric Radiology, University of Bern, Bern, Switzerland.
Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
NMR Biomed. 2015 Nov;28(11):1543-9. doi: 10.1002/nbm.3419. Epub 2015 Oct 1.
It has recently been reported in this journal that local fat depots produce a sizable frequency-dependent signal attenuation in magnetic resonance spectroscopy (MRS) of the brain. If of a general nature, this effect would question the use of internal reference signals for quantification of MRS and the quantitative use of MRS as a whole. Here, it was attempted to verify this effect and pinpoint the potential causes by acquiring data with various acquisition settings, including two field strengths, two MR scanners from different vendors, different water suppression sequences, RF coils, localization sequences, echo times, and lipid/metabolite phantoms. With all settings tested, the reported effect could not be reproduced, and it is concluded that water referencing and quantitative MRS per se remain valid tools under common acquisition conditions.
本刊最近报道，在脑部磁共振波谱（MRS）中，局部脂肪库会产生相当大的频率依赖性信号衰减。如果这是普遍现象，那么这种效应将质疑MRS定量分析中内部参考信号的使用以及MRS整体的定量应用。在此，通过采用各种采集设置获取数据来试图验证这种效应并找出潜在原因，这些设置包括两种场强、来自不同供应商的两台磁共振扫描仪、不同的水抑制序列、射频线圈、定位序列、回波时间以及脂质/代谢物模型。在所有测试设置下，均无法重现所报道的效应，得出的结论是，在常见采集条件下，水参考和定量MRS本身仍然是有效的工具。
