局部匀场在磁共振全身弥散成像中的应用

Application of local shimming in whole body diffusion weighted imaging

目的探讨局部匀场在磁共振全身弥散成像中的应用,提高全身弥散成像的质量。材料与方法对40例行全身弥散扫描成像的患者,在容易出现截断伪影的颈部和胸部交界处分别添加局部匀场和未添加局部匀场,扫描完成后经3D最大信号投影(maximum intensity projection,MIP)法重建,观察是否有截断伪影的出现。结果添加局部匀场后图像的截断伪影明显减少,添加匀场和未添加匀场图像质量之间的差异具有统计学意义(P<0.01)。结论局部匀场在提高磁共振全身弥散成像质量,防止截断伪影的出现上具有重要的意义。

Objective： To discuss the application of local shimming in wholebody diffusion-weighted imaging（WB-DWI） for improving the quality of imaging. Materials and Methods： Forty consecutive patients who underwent WB-DWI scans were included in this study. All of them received two kinds of WB-DWI scans, i.e. with local shimming and without local shimming at the cervicothoracic junction. After that, 3 D maximum intensity projection（MIP） images were reconstructed to check the truncation artifact. Results： The truncation artifact significantly decreased in images with local shimming compared to those without local shimming. Their image quality showed statistical difference（P〈0.01）. Conclusions： Local shimming has important significance in reducing truncation artifact and improving the image quality in WB-DWI.