在极不均匀射频场中改进的磁共振成像。

Improved MR imaging in extremely inhomogeneous radio-frequency fields.

作者信息

Bansal N, Nunnally R L

机构信息

Department of Radiology, University of Texas Southwestern Medical Center, Dallas 75235.

出版信息

Magn Reson Imaging. 1991;9(1):61-5. doi: 10.1016/0730-725x(91)90097-6.

DOI:10.1016/0730-725x(91)90097-6

PMID:2056852

Abstract

An improvement to the method for imaging with extremely inhomogeneous radio-frequency fields is presented which uses a pseudo-noise-modulated selective (PNMS) excitation prepulse to randomize the signal from outside the selected slice. This prepulse reduces the problems that arise from imperfect subtraction involved with the one-dimensional ISIS-type slice selection procedures. The results demonstrate two to three times improvement in the signal-to-noise ratio and reduction in the image artifacts when this prepulse is used.

摘要

本文提出了一种针对极不均匀射频场成像方法的改进，该方法使用伪噪声调制选择性（PNMS）激发预脉冲使所选切片之外的信号随机化。这种预脉冲减少了一维ISIS型切片选择程序中因减法不完善而产生的问题。结果表明，使用该预脉冲时，信噪比提高了两到三倍，图像伪影减少。