Matthaei D, Frahm J, Haase A, Merboldt K D, Hänicke W
Magn Reson Med. 1986 Aug;3(4):554-61. doi: 10.1002/mrm.1910030409.
STEAM (stimulated-echo acquisition mode) imaging techniques recently introduced by the authors are demonstrated to provide a versatile tool for improving the parametric specificity in NMR imaging. Stimulated echoes can be excited by a sequence of at least three rf pulses with flip angles of 90 degrees or less. The main characteristics of the STEAM method are based on the great functional flexibility of an imaging sequence comprising three rf pulses unequal to 180 degrees and three intervals prior to acquisition of the data. Major advantages are the easy access to contiguous multiplanar images, to CHESS (chemical-shift-selective) images, and to T1 information. Moreover, the rf power deposition is considerably reduced as compared to spin-echo NMR imaging sequences. Here first in vivo results on human extremities are presented including contiguous multislice images, multiple CHESS images, and spin-lattice relaxation time images calculated from a series of simultaneously recorded T1-weighted STEAM images.
作者最近引入的STEAM（受激回波采集模式）成像技术被证明是一种用于提高核磁共振成像参数特异性的通用工具。受激回波可以由至少三个翻转角为90度或更小的射频脉冲序列激发。STEAM方法的主要特点基于一个成像序列的巨大功能灵活性，该序列包括三个不等于180度的射频脉冲以及在采集数据之前的三个时间间隔。主要优点是易于获得连续的多平面图像、CHESS（化学位移选择）图像以及T1信息。此外，与自旋回波核磁共振成像序列相比，射频功率沉积显著降低。这里展示了首次在人体四肢上的体内结果，包括连续多层图像、多个CHESS图像以及根据一系列同时记录的T1加权STEAM图像计算得到的自旋晶格弛豫时间图像。
