MR-imaging of the TMJ: artefacts caused by dental alloys.
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.
Behr
M
M
Department of Prosthodontics, University of Regensburg, Germany.
Fellner
C
C
Bayreuther
G
G
Leibrock
A
A
Held
P
P
Fellner
F
F
Handel
G
G
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*
D003722:Dental Alloys