著者

小松 知広 伊東 浩太郎 村岡 宏隆 平原 尚久 岡田 俊也 一木 俊吾 板倉 剛 金田 隆

出版者

特定非営利活動法人 日本歯科放射線学会

雑誌

歯科放射線 (ISSN:03899705)

巻号頁・発行日

vol.60, no.2, pp.42-47, 2021 (Released:2021-04-01)

参考文献数

15

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Background and Purpose: In recent years, a titanium-zirconium alloy(Ti-ZrO2)showing improved mechanical properties compared with commercially pure titanium(Ti)has been introduced. On magnetic resonance imaging(MRI), metal artifacts of dental implants often make diagnosis difficult in clinical situations. Therefore, it is very important to compare metal artifacts of Ti and Ti-ZrO2 dental implants using MRI. However, few studies have made this comparison. The purpose of this study was to investigate and compare metal artifacts of titanium and Ti-ZrO2 dental implants. Materials and Methods: The phantom used in this study was composed of a hollow cylinder with an outer diameter of 20.0cm, and a removable rod of 1.0cm in diameter was placed along the phantom’s central axis. Ti and Ti-ZrO2 alloy implants were placed on this rod. All subjects underwent imaging with a 1.5T MR scanner(Intera Achieva® 1.5T: Philips Medical Systems, Best, The Netherlands)with a SENSE head 8-channel coil. The imaging sequences included turbo spin echo(TSE)T1-weighted imaging(T1WI), TSE T2-weighted imaging(T2WI), short tau inversion recovery(STIR), and single shot echo planar imaging diffusion-weighted imaging(DWI). The full width at half maximum (FWHM) of metal artifact in each phase-encoding direction and frequency-encoding was measured on Image J. The Mann-Whitney U test was used to compare FWHM between Ti and Ti-ZrO2 implants. p-values less than 0.05 were considered to indicate significance. Results: The phase-encoding direction and frequency-encoding of FWHM were significantly different between Ti and Ti-ZrO2 implants on T2WI(p <0.01)and DWI(p< 0.05). There was no significant difference between each material on T1WI and STIR imaging. Conclusions: This study suggested that the Ti-ZrO2 implant is affected by metal artifacts less than the Ti implant on MRI.