摘要
Background Magnetic resonance imaging （MRI） is prone to be deformed by artifacts caused by the presence of metallic materials. The aim of this study was to evaluate the artifacts from galvano-ceramic and metal-ceramic crowns in MRI, in order to analyze their influences on diagnostic interpretation of MRI. Methods Galvano-ceramic and metal-ceramic crowns （Bio98, Wiron99, SP-78, BioKC97） 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 （T1-weighted SE）, T2-weighted spin-echo （T2-weighted SE） and Gradient echo （GE）. Mean and standard deviation of distilled water signal intensity （St） around the sample in the region of interest （500 mm^2） enclosing the whole artifacts were determined, and compared for evaluation of the homogeneity of signal intensity. Images around the sample were acquired and evaluated. Results There were statistically significant differences in the values of signal intensity between acrylic resin control and BioKC97, Wiron99 in the three sequences （P〈0.001）. The mean values of signal intensity for Bio98, SP-78 were significantly different from that of acrylic resin control （RE） in GE sequence （P〈0.001）. No difference was showed between acrylic resin control and galvano-ceramic crown （P 〉0.05）. Images showed that the greatest artifact was a 25 mm ring with distortion in Wiron99 in GE sequence. Conclusions This in vitro study suggested that galvano-ceramic crown had no influence on the MRI, while metal-ceramic crowns caused moderate artifacts in the MRI. Therefore, galvano-ceramic restoration is a valuable alternative in dentistry.
Background Magnetic resonance imaging （MRI） is prone to be deformed by artifacts caused by the presence of metallic materials. The aim of this study was to evaluate the artifacts from galvano-ceramic and metal-ceramic crowns in MRI, in order to analyze their influences on diagnostic interpretation of MRI. Methods Galvano-ceramic and metal-ceramic crowns （Bio98, Wiron99, SP-78, BioKC97） 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 （T1-weighted SE）, T2-weighted spin-echo （T2-weighted SE） and Gradient echo （GE）. Mean and standard deviation of distilled water signal intensity （St） around the sample in the region of interest （500 mm^2） enclosing the whole artifacts were determined, and compared for evaluation of the homogeneity of signal intensity. Images around the sample were acquired and evaluated. Results There were statistically significant differences in the values of signal intensity between acrylic resin control and BioKC97, Wiron99 in the three sequences （P〈0.001）. The mean values of signal intensity for Bio98, SP-78 were significantly different from that of acrylic resin control （RE） in GE sequence （P〈0.001）. No difference was showed between acrylic resin control and galvano-ceramic crown （P 〉0.05）. Images showed that the greatest artifact was a 25 mm ring with distortion in Wiron99 in GE sequence. Conclusions This in vitro study suggested that galvano-ceramic crown had no influence on the MRI, while metal-ceramic crowns caused moderate artifacts in the MRI. Therefore, galvano-ceramic restoration is a valuable alternative in dentistry.
