MRI检查常见伪影的形成与消除方法的探讨

Artifact and its countermeasures of MRI scanning

目的探讨磁共振成像中常见伪影的形成与消除方法,以减少或消除MRI检查时产生的伪影,达到改善图像的质量,为诊断提供良好的影像资料。方法收集我院具有不同程度伪影的138患者例MR图像资料,进行回顾性分析。其中,头颈部扫描51例,脊髓扫描27例,腹部扫描43例,四肢扫描17例。结果运动伪影54例占39.1%,卷褶伪影(含ASSET伪影和马赛克伪影)26例占18.8%,磁化率伪影及金属伪影19例占13.8%,化学位移伪影8例占5.8%,容积效应伪影7例占5.1%,回波平面成像EPIghost伪影9例占6.5%,拉链伪影11例占8%,细线伪影和灯心绒伪影4例占2.9%。结论正确认识各种伪影及其产生的原因,才能充分地利用各种技术,来有效地抑制或消除伪影,提高图像质量。

Objective To discuss the reasons of artifacts in performing MRI scannhng and look for the countermeasures to decrease or eliminate artifacts, which will improve the quality of photographs for diagnosis. Methods 138 patients of MR images which appeared different degree artifacts were reviewed.Head-neck scanning 51 cases; spine scanning 27 cases; abdomen scanning 43 cases; limbs scanning 17 cases. Results 54 cases showed motion artifact whict reached 39.1%. 26 cases showed foldover artifact （including AS SET artifact and mosaic artifact ） which reached 18.8%. 19 cases showed magnetic susceptibility and metal artifact which reached 13.8%. 8 cases showed chemi- cal shift artifact whict reached 5.8%. 7 cases showed volume effect artifact which reached 5.1%. 9 cases showed EPI ghost artifact which reached 6.5%. 11 cases showed zipper artifact which reached 8%. 4 cases showed leptonemaa and corduroy artifact which reached 2.9%. Conclusion In order to gain higher quality MR images, it is very important to know the reasons of various artifacts and make full use of various skills to restraint or eliminate them.