Enzmann D, Augustyn G T
Department of Diagnostic Radiology and Nuclear Medicine, Stanford University School of Medicine, CA 94305-5105.
Radiology. 1989 Sep;172(3):771-81.
Peripheral gating and first-order flow compensation were compared for their ability to improve the quality of second-echo (echo time = 80 msec) brain images obtained with a T2-weighted spin-echo sequence. The contrast-to-noise ratios (C/Ns) for interfaces between brain and cerebrospinal fluid, gray and white matter, and lesion and white matter were measured; the C/N was highest for the combination of gating and flow compensation. This combination of motion compensation also reduced motion artifacts more than did either technique alone. Further improvement in C/N was sought by using a variable-bandwidth pulse sequence, which was compared to a conventional spin-echo sequence. The variable-bandwidth technique increased the C/N of the second-echo image by 27%. The combined use of gating, flow compensation, and the variable-bandwidth option produced high-resolution brain images with a single excitation and retained flexibility in number of sections, number of echoes, and echo times.
比较了外周门控和一阶血流补偿在改善使用T2加权自旋回波序列获得的第二次回波（回波时间 = 80毫秒）脑图像质量方面的能力。测量了脑与脑脊液、灰质与白质、病变与白质之间界面的对比度噪声比（C/N）；门控和血流补偿相结合时C/N最高。这种运动补偿组合比单独使用任何一种技术都更能减少运动伪影。通过使用可变带宽脉冲序列寻求C/N的进一步改善，并将其与传统自旋回波序列进行比较。可变带宽技术使第二次回波图像的C/N提高了27%。门控、血流补偿和可变带宽选项的联合使用通过单次激发产生了高分辨率脑图像，并在切片数量、回波数量和回波时间方面保持了灵活性。
