不同材料固定局部义齿患者行头颈部MRI检查的成像效果和安全性比较

Comparisons of effect and safety of MRI of head and neck in patients with fixed partial dentures made by different materials

目的:采用不同材料制作固定局部义齿,并行头颈部磁共振成像(MRI)检查,探讨其对MRI的影响。方法:招募1例符合条件的志愿者,分别选择钴铬合金、金铂合金和二氧化锆作为内冠材料进行固定局部义齿修复。将3种不同内冠材料固定局部义齿就位于患者口内,进行2种序列(T1-TSE和T2-TSE)MRI扫描。以不戴有修复体的扫描图像作为对照,观察伪影的形状及图像信号的变化,检测3组不同材料义齿伪影累及层数,检测3种材料在冠状位、矢状位和轴位图像中伪影的最大直径,观察固定局部义齿的安全性。结果:各组修复体均产生伪影,其表现形式为信号的强弱变化和图像形状变化;伪影范围在所累及的中心层面最大,在矢状位、冠状位和轴位图像上有不同的表现形式。钴铬合金组义齿伪影累及层数明显多于金铂合金组和二氧化锆组,伪影均限于修复侧颌面部,未累及颈椎及颅脑部。钴铬合金组义齿累及或轻微累及所有邻近组织,金铂合金组和二氧化锆组义齿仅轻微累及下颌牙、舌肌及上颌牙冠。钴铬合金组义齿产生的伪影最大直径大于金铂合金组和二氧化锆组(P<0.05)。修复体未见移位,患者无自觉不适。结论:口腔固定局部义齿在MRI检查时会产生伪影。金铂合金或二氧化锆内冠修复体可明显降低伪影的影响。口内妥善粘接的固定修复体对MRI检查患者不产生安全影响。

Objective:To make the fixed partial dentures with different materials and the magnetic resonance imaging(MRI)examination of head and neck was carried out to investigate the effects of fixed partial dentures on MRI.Methods:A qualified volunteer was recruited,who was conventionally restored using fixed partial denture.Co Cr alloy,Au Pt alloy and Zirconia were chosen as the inner crown materials,respectively.Three kinds of fixed partial dentures were put into the mouth of patient,and2kinds of MRI scan sequences(T1TSE and T2TSE)were performed.The scanning images without restorations were used as controls.The change of shape,image signal and involving layers of artifacts of different materials in three groups were observed.The maximum diameter of artifact of three materials in coronal,sagittal and axial images were detected.The safeties of fixed partial dentures were observed.Results:The artifacts were found in all the restorations and showed the changes of strengthen and weaken of the signal and the changs of shapes of images.The range of artifacts was the largest in the involved central plane and varied in sagittal,coronal and axial images.The number of involving layers of artifacts in Co Cr alloy group was significantly more than those in Au Pt alloy and Zirconia groups;the artifacts were limited in the repaired lateral maxillofacial region without the cervical spine and head region involvement.The artifacts in Co Cr alloy group involved or slightly involved in all adjacent tissues,and the artifacts in Au Pt alloy and Zirconia groups only slightly affected the mandibular teeth,lingual muscles and maxillary crowns.The maximum diameter of artifacts in Co Cr alloy group was larger than those in Au Pt alloy group and Zirconia group(P<0.05).No displacement was found in the prosthesis,and the patient had no discomfort.Conclusion:The artifact of the fixed partial denture can be seen in MRI examination.Co Cr alloy or zirconia can significantly reduce the effect of artifact.Fixed adhesive prosthesis in mouth does not affect the safety of MRI examination.