Dzmitry Zhylich1, Pradeep Krishnan2, Prakash Muthusami2, Tammy Rayner2, Manohar Shroff3, Andrea Doria3, Bryan Tompson4, Wendy Lou5, Sunjay Suri6. 1. Private Practice, Ottawa, Ontario, Canada. 2. Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada. 3. Department of Medical Imaging, University of Toronto; Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada. 4. Discipline of Orthodontics, Faculty of Dentistry, University of Toronto; Division of Orthodontics, Hospital for Sick Children, Toronto, Ontario, Canada. 5. Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada. 6. Discipline of Orthodontics, Faculty of Dentistry, University of Toronto; Division of Orthodontics, Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address: sunjaysuri@hotmail.com.
Abstract
INTRODUCTION: The influence of 4 commonly used fixed orthodontic appliances on artifact formation and diagnostic quality of magnetic resonance (MR) images of the head produced by a 3-T MR scanner was studied. METHODS: Stainless steel brackets, ceramic brackets, combination of ceramic brackets and steel molar tubes, and multistranded steel mandibular lingual retainers were embedded into custom-made trays for each of 10 adult subjects. Head MR scans of 9 regions were acquired for each subject wearing these trays. Sagittal T1-weighted, axial T2-weighted, axial gradient-recalled, axial diffusion-weighted, noncontrast axial MR angiography, and axial fluid-attenuated inversion recovery MR sequences were included. Two neuroradiologists evaluated image distortions and diagnostic qualities of the 1314 acquired images (13860 image slices). RESULTS: The images were affected by appliance, head region, and MR sequence. Stainless steel brackets and molar tubes affected the images the most, and ceramic brackets caused minimal image distortion. CONCLUSIONS: Head MR images are differentially affected by orthodontic appliances. The appliance, region imaged, and MR sequence should be considered before imaging patients wearing fixed orthodontic appliances.
INTRODUCTION: The influence of 4 commonly used fixed orthodontic appliances on artifact formation and diagnostic quality of magnetic resonance (MR) images of the head produced by a 3-T MR scanner was studied. METHODS:Stainless steel brackets, ceramic brackets, combination of ceramic brackets and steel molar tubes, and multistranded steel mandibular lingual retainers were embedded into custom-made trays for each of 10 adult subjects. Head MR scans of 9 regions were acquired for each subject wearing these trays. Sagittal T1-weighted, axial T2-weighted, axial gradient-recalled, axial diffusion-weighted, noncontrast axial MR angiography, and axial fluid-attenuated inversion recovery MR sequences were included. Two neuroradiologists evaluated image distortions and diagnostic qualities of the 1314 acquired images (13860 image slices). RESULTS: The images were affected by appliance, head region, and MR sequence. Stainless steel brackets and molar tubes affected the images the most, and ceramic brackets caused minimal image distortion. CONCLUSIONS: Head MR images are differentially affected by orthodontic appliances. The appliance, region imaged, and MR sequence should be considered before imaging patients wearing fixed orthodontic appliances.
Authors: Mikael Sonesson; Fahad Al-Qabandi; Sven Månsson; Salem Abdulraheem; Lars Bondemark; Kristina Hellén-Halme Journal: Imaging Sci Dent Date: 2021-01-29