Abstract:

Objective To explore the influence of conventional metal materials in oral cavity on brain magnetic resonance imaging（MRI）. Methods Four kinds of metal materials（metal ligature wire, forging hard and slotless denture, casting nichrome denture, casting copper alloy denture） in oral cavity were scanned through MRI. FSE sequence T1 weighted imaging（FSE T1）, EPI diffusion-weighted imaging（DWI） sequence of ordinary, Propeller DWI imaging were used. Results In FSE T1 sequence, metal ligature wire and forging hard and slotless denture produced serious false image, casting nichrome denture produced moderate false image, casting copper alloy denture produced only little false image. In EPI DWI sequence, obvious magnetic-sensitive false image were produced in the dissection tissue of the brain by metal ligature wire. While in Propeller DWI sequence, magnetic -sensitive false image were greatly reduced and satisfactory images were formed. Conclusion Different metal materials in oral cavity have different influence on the MRI. The false images produced by different metal materials are closely related to the type of the material. Magnetic-sensitive false images can be eliminated by Propeller DWI technique.

Key words: magnetic resonance imaging, metal, false image