title: MR-imaging of the TMJ: artefacts caused by dental alloys.
abstract: The aim of the study was to investigate the influence of dental alloys and their components on magnetic resonance imaging of the temporomandibular joint. A plaster and a water- filled acrylic resin phantom - representing the disc and the condyle of the TMJ - were used. Cylindrical crow-type samples of 13 alloys and 14 pure substances were investigated. All alloys were examined with regard to their magnetic susceptibility, using a vibrating sample magnetometer. Metallic artefacts appeared on spin-echo technique as distortions, and on gradient-echo technique signal loss could be observed. Precious alloys were shown to be diamagnetic. The non precious alloys we investigated were paramagnetic. Paramagnetic alloys with a magnetic molar-susceptibility Cmol > 2000 x10(-6) cm3/mol can produce clinically relevant artefacts.
authors.affiliation: Department of Prosthodontics, University of Regensburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Behr
authors.forename: C
authors.initials: C
authors.lastname: Fellner
authors.forename: G
authors.initials: G
authors.lastname: Bayreuther
authors.forename: A
authors.initials: A
authors.lastname: Leibrock
authors.forename: P
authors.initials: P
authors.lastname: Held
authors.forename: F
authors.initials: F
authors.lastname: Fellner
authors.forename: G
authors.initials: G
authors.lastname: Handel
mesh_terms: D016477:Artifacts; D003722:Dental Alloys / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D013704:Temporomandibular Joint / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis*
chemical_list: D003722:Dental Alloys