钴铬合金磁共振成像伪影范围的研究

Studies on Range of Artifacts from CoCr Alloy in Magnetic Resonance Imaging

目的:研究钴铬修复体磁共振成像伪影范围。方法:组一制作5mm×5mm×1mm钴铬合金,放置于T1序列中,比较钴铬与其他5种修复材料磁共振成像伪影大小。组二用钴铬合金制作中切牙、尖牙、第二前磨牙金属底冠、第一二磨牙金属冠,放置于T1序列中,观察磁共振伪影范围。结果:组一中钴铬合金成像伪影最大。组二中钴铬合金冠在上,下颌矢状面上,冠状面,横断面上伪影涉及层数分别为15、19、19、15、18、18。在横断面上显示的单颗牙成像,伪影平均高度是牙冠平均高度的8～10倍,宽度为4～5倍。结论:钴铬合金对磁共振影响最大,其修复体涉及扫描层数多。

Objectives： To evaluate the range of artifacts generated by CoCr alloy.Methods： Group1： 5mm×5mm×1mm alloies were embedded in 50mm×50mm×50mm agar.They were compared artifacts from CoCr with other five dental materials in MRI T1 sequences.Group2： CoCr restorations were embedded in 150mm×150mm×150mm agar.The range of artifacts was observed.Results： The artifacts from CoCr had shown significant distoration compared with other five dental materials.Group2： the numbers of slices that the atifacts influence in maxillary and mandible in transverse,coronal and sagittal planes were 15,19,19,15,18,18.In transverse image,the height of artifact was 8-11 times of the crown,and 4-5 times width of crown.Conclusion： CoCr had a significant influence on artifacts in MRI,which involved many slices.