金沉积烤瓷冠和贵金属烤瓷冠对磁共振图象的影响

Influence of Galvano-ceramic and Precious Metal-ceramic Crowns on Magnetic Resonance Imaging

目的:通过对金沉积烤瓷冠和贵金属烤瓷冠在磁共振图象(MRI)中形成的金属伪影进行分析,探讨其对磁共振图象的影响。方法:采用同一个模型分别制作金沉积烤瓷冠和贵金属烤瓷冠,以及作为对照组的树脂全冠。将样本按照制作的材料分为GA组;BioKC97组;SP-78组;Bio98组和作为对照的RE组。所有的样品置于蒸馏水中进行MRI三种不同序列(T1,T2加权相回波和梯度序列)扫描,通过软件分析获取样本周围蒸馏水信号强度(500mm2)的平均值和标准差。结果:GA组与RE组之间无差异;BioKC97组与RE组在3个序列中均有显著性差异(P=0.000);SP-78组;Bio98组与RE组仅在梯度序列中有显著性差异(P=0.000)。结论:金沉积烤瓷冠没有在MRI中形成金属伪影,对MRI没有影响,而贵金属烤瓷冠对MRI有一定的影响。

Objective ： To evaluate the artifacts from galvano - ceramic and precious metal - ceramic crowns in magnetic resonance imaging （MRI）. Methods ： Galvano - ceramic and metal - ceramic crowns （ Group BioKC97, SP - 78, Bio98 ） were fabricated with the same model. All materials were imaged by means of 1.5T MRI apparatus with three different sequences （T1 -weighted spin- echo, T2- weighted spinecho and Gradient echo）. Mean and Standard deviation of distilled water signal intensity （SI） around the sample in the region of interest （500 mm） enclosing the whole artifacts was determined, and compared for evaluation of the homogeneity of SI. Results ： There was statistical difference in the SI between acrylic resin control and BioKC97 in the three sequences （P =0.000）. The mean SI for Bio98 and SP- 78 were significantly different from that of acrylic resin control （RE） in GE sequence （ P = 0. 000）. No difference was showed between acrylic resin control and galvano - ceramic crown. Conclusion ： Within the limitations of this in - vitro study, galvano - ceramic crown does not cause artifact in the MRI. However, precious metal - ceramic crowns cause moderate artifacts in the MRI.