目的探讨钴铬合金、纯钛及银 钯合金材料局部固定义齿对头颈部MRI检 查的影响。方法 招募本院39例局部固定 义齿志愿者为研究对象，患者均进行头颈 部MRI检查，选用3.0T的及1.5T磁共振常 用的3种序列(SE-T1WI序列、TSE-T2WI序 列、GRE-T2WI序列)，测量并分析伪影。 结果 不同场强下，三种修复材料的TSE序 列的伪影面积、最大伪影直径由高到低依 次为钴铬合金、纯钛、银钯合金，且组间 差异均具有统计学意义(P<0.05)；TSE序 列的T1/T2声像图主要表现为信号丢失、 信号强度改变、图像扭曲，且在不同平面 上呈现不同形状，GRE序列伪影要比TSE序 列大，其图像伪影整体成像质量差，伪影 主要表现为边界不清的近似圆形信号丢失 区域。结论 口腔义齿修复材料是影响头 颈部MRI产生伪影的重要因素，一般情况 下，GRE序列较TSE序列更为敏感，高磁场 的MRI产生更高的伪影，而银钯合金材料 较钴铬合金、纯钛影响较小。

Objective To investigate the effect of fixed partial dentures made by Co-Cr alloy, pure titanium and Ag-Pd alloy on head and neck MRI examination. Methods A total of 39 volunteers with fixed partial dentures in the hospital were selected, and they were examined by head and neck MRI. The 3 common sequences (SE-T1WI sequence, TSE-T2WI sequence and GRE-T2WI sequence) of 3.0T and 1.5T MRI were used to measure and artifacts were analyzed. Results Under different field strength, the artifact area and the maximum artifact diameter of TSE sequence of three restorative materials ranged from high to low was Co-Cr alloy, pure titanium and Ag-Pd alloy, with statistically significant differences between groups (P<0.05). The T1/T2 images of TSE sequence showed loss of signal, changes of signal intensity and image distortion, showing different shapes on different planes. The artifacts of GRE sequence were larger than the TSE sequence, and the overall image quality of its artifacts was poor. Artifacts mainly showed approximate circular signal loss area with unclear boundary. Conclusion The denture restorative material is an important factor affecting the artifact of head and neck MRI. In general, GRE sequence is more sensitive than TSE sequence. MRI with high magnetic field has higher artifact, while Ag-Pd alloy has less influence than Co-Cr alloy or pure titanium.