两种常见的口腔非贵金属合金桩核冠MRI伪影的比较研究  

Comparative study on magnetic resonance imaging artifacts of oral non-noble metal post- core-crown

作　　者：陈一 李晖 梁锐英 王雅静 

机构地区：[1]华北理工大学口腔医学院修复科,河北唐山063000 [2]华北理工大学附属医院MR室,河北唐山063000

出　　处：《生物医学工程与临床》2015年第6期559-563,共5页Biomedical Engineering and Clinical Medicine

基　　金：河北省卫生厅青年科技课题科研基金项目资助(20150856)

摘　　要：目的探讨临床常见的两种非贵金属合金桩核冠MRI检查时不同序列伪影大小,以更好地指导临床对材料的选取。方法选用钴铬合金、镍铬合金、丙烯酸树脂材料,用钴铬合金和镍铬合金分别制成左下6标准桩核冠模型做为实验组(镍铬合金组、钴铬合金组),用丙烯酸树脂制成大小形状相同的桩核冠模型做为对照组,将模型固定于水模中。应用1.5 T MRI扫描仪,头线圈,对实验组及对照组桩核冠行横断面T1加权成像(T1WI)、T2加权成像(T2WI)、T2*加权成像(T2*WI)、液体衰减反转恢复(FLAIR)、弥散加权成像(DWI)序列扫描。应用SAS V8统计学软件进行分析。结果镍铬合金组、钴铬合金组均出现金属伪影,表现为图像的变形,T2*WI序列影像金属伪影表现为低信号,而其他序列伪影表现为不规则低信号,周边环以窄条状高信号;对照组各个序列影像基本无伪影出现。3种材料MRI伪影由大到小依次为镍铬合金组、钴铬合金组、对照组(P<0.01)。不同序列伪影大小不同,DWI金属伪影最大,T2*WI次之,然后是T2WI,T1WI与FLAIR序列金属伪影最小(P<0.01)。结论镍铬合金MRI伪影大于钴铬合金。自旋回波和快速自旋回波序列伪影相对较小,为金属伪影不可避免时的首选序列。Objective To investigate the sizes of MRI artifacts of two clinically applied non-noble metal post-core-crown at different sequence, and provide guidance of clinical selection for material. Methods The selected materials were Ni-Cr alloy, Co-Cr alloy and acrylic resin. Two kinds of non-noble metal dental materials（Ni-Cr alloy and Co-Cr alloy） were molded into standard post-core-crown models as experimental group, while acrylic resin post-core- crown models with the same size and shape were used as control group, and all the models were fixed in water mold. The Ni-Cr alloy, Co-Cr alloy and acrylic resin post-core-crown models were scanned by 1.5 T MRI with head coils. TI weighted imaging（T1WI）, T2 weighted imaging（T2WI）, T2^＊ weighted imaging（TE＇WI）, fluid attenuated inversion recovery（FLAIR）, diffusion weighted imaging（DWI） sequence of post-core- crown at cross section of the two groups were scanned respectively. The statistical software SAS V8 was used to analyze the data. Results There were metal artifacts in both Ni-Cr alloy and Co-Cr alloy, and the artifacts acted as image deformations. The artifacts signal in T2^＊WI was weak, while artifacts in other sequences appeared as irregular weak signals surrounded by strip strong signals. There were no artifacts in most of the sequences in control group. The sizes of artifacts decreased（from big to small） in order of Ni-Cr alloy, Co-Cr alloy and Acrylic resin post-core-crown（P 〈 0.01）. The sizes of artifacts were different at different sequences, and the sizes varied from big to small in order of DWI, T2＊WI, T2WI, T^WI and FLAIR（P 〈 0.01）. Conclusion It is demonstrated that artifact of Ni-Cr alloy is bigger than that of Co-Cr alloy, and the better choices for metal restoration of oral cavity are spin-echo sequence and fast spin-echo sequence with smaller artifacts.

关 键 词：金属 钴铬合金 镍铬合金 桩核冠 伪影 磁共振(MRI) 

分 类 号：R445.2[医药卫生—影像医学与核医学] R318.08[医药卫生—诊断学]