Ling Zhu1, Yi Chen2, Jie Yang3, Xiaofeng Tao4, Yan Xi5. 1. 1 Department of Radiology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai , China. 2. 2 Imaging research group, UEG Medical Imaging Equipment Co. Ltd. , Shanghai , China. 3. 3 Department of Diagnostic Imaging, Division of Oral & Maxillofacial Radiology, Temple University School of Dentistry, Temple University School of Medicine , Philadelphia, PA , USA. 4. 4 Department of Radiology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai , China. 5. 5 Imaging research group, UEG Medical Imaging Equipment Co. Ltd. , Shanghai , China.
Abstract
OBJECTIVES: : Metal artefacts are highly common in dental CT images because of the high X-ray attenuation of metallic dental fillings and implants. This study presents an evaluation of the virtual monochromatic imaging for metal artefact reduction by a recently introduced dental spectral cone beam CT, which is the first commercial dental spectral CBCT with flat-panel detector. METHODS: : We carried out phantom experiments and clinical trials in this study. In the phantom study, the head phantom with metallic dental fillings and implants of various materials was scanned. Moreover, standard deviation, metal artefact index, and contrast-to-noise ratio were analyzed for fixed region of interest. Patient study included 23 patients with metallic fillings and metal implants. Traditional CT images and virtual monochromatic images were produced in a single scan, ensuring that the comparison can be made within the same patient and same location. Standard deviation and metal artefact index were analyzed for fixed region of interest. RESULTS: : The phantom study and patient study showed that the metal artefacts caused by metallic dental fillings are well-suppressed by the virtual monochromatic imaging. Moreover, the improvements in virtual monochromatic imaging in terms of image quality are more pronounced for small dental fillings.. The noise increase in image slices without metallic objects is a side-effect of the virtual monochromatic images. CONCLUSIONS: : Virtual monochromatic imaging by spectral cone beam CT reduces the metal artefact and improves the image contrast-to-noise ratio around dental metallic fillings. This kind of imaging would be recommended for patients with dental metallic fillings.
OBJECTIVES: : Metal artefacts are highly common in dental CT images because of the high X-ray attenuation of metallic dental fillings and implants. This study presents an evaluation of the virtual monochromatic imaging for metal artefact reduction by a recently introduced dental spectral cone beam CT, which is the first commercial dental spectral CBCT with flat-panel detector. METHODS: : We carried out phantom experiments and clinical trials in this study. In the phantom study, the head phantom with metallic dental fillings and implants of various materials was scanned. Moreover, standard deviation, metal artefact index, and contrast-to-noise ratio were analyzed for fixed region of interest. Patient study included 23 patients with metallic fillings and metal implants. Traditional CT images and virtual monochromatic images were produced in a single scan, ensuring that the comparison can be made within the same patient and same location. Standard deviation and metal artefact index were analyzed for fixed region of interest. RESULTS: : The phantom study and patient study showed that the metal artefacts caused by metallic dental fillings are well-suppressed by the virtual monochromatic imaging. Moreover, the improvements in virtual monochromatic imaging in terms of image quality are more pronounced for small dental fillings.. The noise increase in image slices without metallic objects is a side-effect of the virtual monochromatic images. CONCLUSIONS: : Virtual monochromatic imaging by spectral cone beam CT reduces the metal artefact and improves the image contrast-to-noise ratio around dental metallic fillings. This kind of imaging would be recommended for patients with dental metallic fillings.
Entities:
Keywords:
cone-beam CT; dental; metal artefact; spectral; virtual monochromatic imaging
Authors: Boyuan Li; Derrek Spronk; Yueting Luo; Connor Puett; Christina R Inscoe; Donald A Tyndall; Yueh Z Lee; Jianping Lu; Otto Zhou Journal: PLoS One Date: 2022-02-03 Impact factor: 3.240