桩钉对磁共振成像伪影形成的影响

Dental Posts Restoration Affected the Development of MRI Artifacts

目的:检测口腔内不同长度桩钉对磁共振图像的影响;并对不同金属制作的桩钉对磁共振图像的影响进行比较。方法:先对两种金属不同长度的桩钉(软质钴铬合金:15mm、13mm、11mm、9mm、7mm、5mm;镍铬合金:15mm、11mm、5mm)在1.0T的场强中做扫描,再从中选取两种长度的桩钉(软质钴铬合金:15mm、11mm)在0.15T的磁场中扫描做对照。结果:不同长度的桩钉在相同检测条件下所产生的伪影面积大小有显著性差异。同时伪影与桩钉制作所选用合金种类及检测时磁场强度、成像序列有关。结论:临床制作桩钉时,在保证固位力的前提下应尽可能减少桩钉的长度,以将伪影的影响降到最低。

Objectives： To evaluate dental post restoration on affecting the development of MRI with different lengths and different kinds of metals. Methods： Two kinds of metal posts with different lengths （soft CO -Cr alloy ：15mm, 13mm, 11 mm, 9mm, 7mm; 5mm, Ni - Cr alloy ： 15mm, 11 mm, 5mm） were imaged by 1.0T magnetic resonance. Two posts with different lengths were imaged by 0.15T magnetic resonance. Results： The surface of artifacts developed by the pests with different lengths were significant different. And the development of artifacts was related to the alloy category, strength of magnetic resonance and imaging program. Conclusion： To minimize the effect on the MRI artifacts and assure the adequate retention, the length of the post should be as shorter as possible.