Nitz W R
Siemens AG, Medical Soulutions, MR-Applikationsentwicklung, Erlangen.
Radiologe. 2003 Sep;43(9):745-63, quiz 764-5. doi: 10.1007/s00117-003-0946-z.
The role of magnetic resonance imaging in clinical routine is still increasing. The large number of possible MR acquisition schemes reflects the variety of tissue-dependent parameters that may influence the contrast within the image. Those schemes can be categorized into gradient echo and spin echo techniques. Within these groups, further sorting can be done to differentiate between single-echo, multi-echo, and single-shot techniques. Each of these techniques can be combined with preparation schemes for modifying the longitudinal magnetization. Hybrids are found between the groups, which are those techniques that utilize spin echoes as well as gradient echoes. Academic groups as well as vendors often have different sequence acronyms for the same acquisition scheme. This contribution will sort these sequence acronyms into the previously mentioned scheme. The basic principle of the data acquisition is elaborated on and hints are given for potential clinical applications. Besides the sequence-specific acronyms, new abbreviations have surfaced recently in conjunction with parallel acquisition techniques." The latter means the utilization of multiple surface coils where the position and the sensitivity profile of the coils provide additional spatial information, allowing the application of reduced matrixes leading to a shorter measurement time.
磁共振成像在临床常规中的作用仍在不断增强。大量可能的磁共振采集方案反映了各种可能影响图像对比度的组织相关参数。这些方案可分为梯度回波和自旋回波技术。在这些类别中，还可以进一步分类以区分单回波、多回波和单次激发技术。这些技术中的每一种都可以与用于修改纵向磁化的准备方案相结合。在不同类别之间还存在混合技术，即那些同时利用自旋回波和梯度回波的技术。学术团体和设备供应商对于相同的采集方案往往有不同的序列缩写。本文将把这些序列缩写按照上述方案进行分类。详细阐述了数据采集的基本原理，并给出了潜在临床应用的提示。除了特定序列的缩写外，最近还出现了与并行采集技术相关的新缩写。后者是指利用多个表面线圈，其中线圈的位置和灵敏度分布提供了额外的空间信息，从而允许应用降矩阵，进而缩短测量时间。
