Stollberger R, Wach P
Magnetic Resonance Institute, University of Graz, Austria.
Magn Reson Med. 1996 Feb;35(2):246-51. doi: 10.1002/mrm.1910350217.
The authors describe a method for accurate in vivo multislice imaging of the active component of the B1 field which is based on a previously proposed method, which uses the signal intensity ratio of two images measured with different excitation angles, and a repetition time TR 5 > or = 5 T1. The new method essentially reduces repetition and scan time by means of an additional compensating pulse. The suppression of T1 effects by this pulse are verified with simulations and measurements. Further investigations concerned the influence of slice selective excitation and magnetization transfer in multislice imaging to the B1 field determination. The stability and accuracy of the presented method is shown by several phantom and in vivo measurements. With the described method the active B1 field can be determined in vivo in 23 cross-sections in less than 6 min.
作者描述了一种用于对B1场的活性成分进行精确体内多层成像的方法，该方法基于先前提出的一种方法，后者利用不同激发角度测量的两幅图像的信号强度比以及重复时间TR≥5T1。新方法通过一个额外的补偿脉冲从本质上减少了重复时间和扫描时间。通过模拟和测量验证了该脉冲对T1效应的抑制作用。进一步的研究涉及多层成像中切片选择性激发和磁化传递对B1场测定的影响。通过多个体模和体内测量展示了所提出方法的稳定性和准确性。使用所描述的方法，可在不到6分钟的时间内在体内23个横截面中确定活性B1场。
