Byrd S E, Tomita T, Palka P S, Darling C F, Norfray J P, Fan J
Department of Radiology, Children's Memorial Hospital, Chicago, IL 60614, USA.
J Natl Med Assoc. 1996 Oct;88(10):649-54.
Magnetic resonance spectroscopy (MRS) provides a means to assess functional (metabolic activity) of the brain. It is now possible to perform MRS in a clinical setting with the use of an inexpensive software package called Proton Brain Exam/Single Voxel (PROBE/SV) developed by General Electric Medical System for use on their 1.5-T MR scanner. We have used PROBE for over a year and have found it to be useful in the evaluation of brain abnormalities. Most of our experience with MRS has been in the evaluation of children with brain tumors. In this first article of a two-part series, a simplified introduction to single-voxel MRS is presented, including: 1) the differences in the normal MRS spectra of the brains of infants, children, and adults demonstrating the variation in peaks of the common metabolities (N-acetylasparate, creatine, and choline); 2) the two types of MRS pulse sequences, stimulated echo acquisition mode (STEAM), a T1-weighted sequence, and point resolved spectroscopy (PRESS), a T2-weighted sequence; and 3) some of the factors that influence the production of diagnostic and nondiagnostic spectra. Part Two will report findings on the efficacy of MRS in children with brain tumors. With a basic understanding of MRS, the abnormal spectra in the diagnosis of brain tumors can be appreciated.
磁共振波谱成像（MRS）提供了一种评估大脑功能（代谢活性）的方法。现在，使用通用电气医疗系统公司开发的一种名为质子脑检查/单体素（PROBE/SV）的廉价软件包，在临床环境中进行MRS检查成为可能，该软件包可用于其1.5-T磁共振扫描仪。我们使用PROBE已有一年多时间，发现它在评估脑异常方面很有用。我们在MRS方面的大部分经验都来自对患有脑肿瘤儿童的评估。在这个分为两部分的系列文章的第一篇中，将对单体素MRS进行简要介绍，内容包括：1）婴儿、儿童和成人脑正常MRS波谱的差异，展示了常见代谢物（N-乙酰天门冬氨酸、肌酸和胆碱）峰的变化；2）两种MRS脉冲序列，即受激回波采集模式（STEAM），一种T1加权序列，以及点分辨波谱法（PRESS），一种T2加权序列；3）一些影响诊断性和非诊断性波谱产生的因素。第二部分将报告MRS在患有脑肿瘤儿童中的疗效研究结果。对MRS有一个基本的了解后，就能理解脑肿瘤诊断中的异常波谱。
