Glover G H
Department of Diagnostic Radiology and Nuclear Medicine, Stanford University School of Medicine, CA 94305-5105.
J Magn Reson Imaging. 1991 Sep-Oct;1(5):521-30. doi: 10.1002/jmri.1880010504.
Extensions to a previously described three-point Dixon magnetic resonance imaging technique are presented that use alternative water/fat phase-encoding strategies. The technique is generalized to phase encoding of (-theta, O, theta) or (O, theta, 2 theta) radians, and the signal-to-noise ratio (S/N) performance is evaluated. It was found that a theta of 2 pi/3 radians has optimal S/N but that a theta of pi radians is a good compromise and that phase encoding of (O, pi, 2 pi) radians offer an advantage over the previous method, which used (-pi, O, pi) increments, in that a T2' (intravoxel susceptibility dephasing) image may be obtained in addition to the usual water, fat, and Bo images. A new four-point method with phase encoding of (O, pi, 2 pi, 3 pi) radians that can also provide a measure of the spectral width of the fat resonance is suggested. The disadvantages of the method are the extra imaging time and low S/N efficiency.
本文介绍了对先前描述的三点狄克逊磁共振成像技术的扩展，该扩展使用了替代的水/脂肪相位编码策略。该技术被推广到（-θ，0，θ）或（0，θ，2θ）弧度的相位编码，并对信噪比（S/N）性能进行了评估。结果发现，2π/3弧度的θ具有最佳的信噪比，但π弧度的θ是一个很好的折衷方案，并且（0，π，2π）弧度的相位编码比以前使用（-π，0，π）增量的方法具有优势，因为除了通常的水、脂肪和B₀图像外，还可以获得T2'（体素内磁化率去相位）图像。提出了一种新的四点方法，其相位编码为（0，π，2π，3π）弧度，该方法还可以提供脂肪共振频谱宽度的测量值。该方法的缺点是额外的成像时间和低信噪比效率。
