13 research outputs found
Artifacts In Magnetic Resonance Imaging and Computed Tomography Caused By Dental Materials
BACKGROUND: Artifacts caused by dental restorations, such as dental crowns, dental fillings and orthodontic appliances, are a common problem in MRI and CT scans of the head and neck. The aim of this in-vitro study was to identify and evaluate the artifacts produced by different dental restoration materials in CT and MRI images. METHODS: Test samples of 44 materials (Metal and Non-Metal) commonly used in dental restorations were fabricated and embedded with reference specimens in gelatin moulds. MRI imaging of 1.5T and CT scan were performed on the samples and evaluated in two dimensions. Artifact size and distortions were measured using a digital image analysis software. RESULTS: In MRI, 13 out of 44 materials produced artifacts, while in CT 41 out of 44 materials showed artifacts. Artifacts produced in both MRI and CT images were categorized according to the size of the artifact. SIGNIFICANCE: Metal based restoration materials had strong influence on CT and less artifacts in MRI images. Rare earth elements such as Ytterbium trifluoride found in composites caused artifacts in both MRI and CT. Recognizing these findings would help dental materials manufacturers and developers to produce materials which can cause less artifacts in MRI and CT images
MRI and CT artifacts produced by temporary filling materials (Group 2).
<p>−/+ test specimen not recognizable, adjacent reference specimen recognizable.</p><p>−/+− test specimen not recognizable, adjacent reference specimen partially recognizable.</p
Dimensions of (A) wedge-shaped specimens and (B) reference.
<p>Dimensions of (A) wedge-shaped specimens and (B) reference.</p
MRI artifact produced by Remanium in (A) T1 and (B) T2.
<p>MRI artifact produced by Remanium in (A) T1 and (B) T2.</p
Streak artifact produced by Zirconium dioxide in CT.
<p>Streak artifact produced by Zirconium dioxide in CT.</p
MRI and CT artifacts produced by composites (Group 1).
<p>−/+ Test specimen not recognizable, adjacent reference specimen recognizable.</p><p>−/+− Test specimen not recognizable, adjacent reference specimen partially recognizable.</p><p>−/(+) Test specimen not recognizable, adjacent reference specimen recognizable but changed size or shape.</p
MRI artifact produced by Tetric EvoCeram in (A) T1 and (B) T2.
<p>MRI artifact produced by Tetric EvoCeram in (A) T1 and (B) T2.</p
MRI and CT artifacts produced by Metal alloys (Group 4).
<p>−/+ test specimen not recognizable, adjacent reference specimen recognizable.</p><p>−/+− test specimen not recognizable, adjacent reference specimen partially recognizable.</p