MR自旋回波与快速自旋回波脉冲序列对图像质量的影响

目的:探讨双梯度MRl系统在自旋回波SE(spin echo)、快速自旋回波FSE(fast spin echo)成像序列时的成像质量。方法:采用GE双梯度MRI系统和正交发射/接收一体化裂口线圈分别应用SE和FSE脉冲序列,对Magp nan-SMR170MR成像参数测试体模分别行zoom及whole梯度模式扫描。比较两序列成像的图像质量参数。基于Matlab7.0编写程序代码,求图像的信噪比及均匀性、层厚和层间距、几何畸比率等图像参数;空间分辨率直接在MRI的工作站显示器上读取结果:在SE序列成像时,均匀性、层厚误差、层间距误差、垂直方向的几何畸变率,空间分辨率图像质量参数优于FSE成像序列(P<0.01);而信噪比及水平方向的畸变率,FSE成像序列优于SE成像序列(P<0.05)。结论:在临床应用中,需要较高精度的病灶测量以及为临床提供手术范围时,要综合考虑各个成像参数,选择成像序列。

Comparison of MR Imaging Quality Parameters between Spin Echo and Fast Spin Echo Imaging Pulse Sequence

Objective To compare imaging quality parameters between spin echo（SE） and fast spin echo（FSE） imaging pulse sequence in MRI.Methods GE dual gradient MR1 system and orthogonal launch/acceptance integration gap coil with SE and FSE pulse sequence respectively were used to scan Magphan-SMR170 imaging parameters testing phantom in zoom and whole mode.The imaging quality parameters of the two sequences were compared.The imaging quality parameters including SNR,image uniformity,slice thickness error,slice separation,spatial linearity were measured or calculated hy Matlab 7.0 programming.Spatial resolution was read on the screen directly.Results The uniformity,thickness error, interlayer spacing error,geometric distortion rate of perpendicular direction and spatial resolution of SE were better than those of FSE imaging sequence（P0.01）.But the SNR and geometric distortion rate of horizontal direction of FSE were better than those of SE imaging sequence（P0.05）.Conclusion In clinical application,high precision measurement of the lesions is required,and various imaging parameters should be considered to select imaging sequence when offering surgery extent to the clinic