Polyane Mazucatto Queiroz1, Francisco Carlos Groppo2, Matheus Lima Oliveira3, Francisco Haiter-Neto3, Deborah Queiroz Freitas4. 1. PhD Student, Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Sao Paulo, Brazil. Electronic address: polyanequeiroz@hotmail.com. 2. Professor, Department of Physiological Sciences, Area of Pharmacology, Piracicaba Dental School, University of Campinas, Sao Paulo, Brazil. 3. Professor, Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Sao Paulo, Brazil. 4. Associate Professor, Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Sao Paulo, Brazil.
Abstract
OBJECTIVE: The aim of this study was to evaluate the efficacy of a metal artifact reduction (MAR) algorithm in cone beam computed tomography (CBCT) images of dental materials obtained with different field-of-view (FOV) and voxel sizes. STUDY DESIGN: Two imaging phantoms were custom-made of acrylic resin. Each phantom had 3 cylinders made of the same dental material: dental amalgam or copper-aluminum alloy. CBCT scans were obtained separately for each of the imaging phantoms using the Picasso-Trio CBCT (Vatech, Hwaseong, Republic of Korea) unit at 4 FOV sizes and 2 voxel sizes. Each imaging phantom was scanned with and without MAR. All images were evaluated in the OnDemand3D software (Cybermed, Seoul, Republic of Korea) and image noise (gray value variability) was calculated as the standard deviation (SD) of the gray values of regions of interest around the dental material cylinders. Data were compared by the Friedman test and Dunn test (α = 0.05). Intraclass correlation coefficient (ICC) was calculated to assess intraobserver reliability. RESULTS: MAR significantly reduced (P < .05) image noise around the dental materials, irrespective of FOV and voxel sizes, with an ICC of 0.997. CONCLUSIONS: The efficacy of MAR was similar for the different FOV and voxel sizes studied. Hence, imaging protocols and the use of MAR algorithm should be based on the selection criteria.
OBJECTIVE: The aim of this study was to evaluate the efficacy of a metal artifact reduction (MAR) algorithm in cone beam computed tomography (CBCT) images of dental materials obtained with different field-of-view (FOV) and voxel sizes. STUDY DESIGN: Two imaging phantoms were custom-made of acrylic resin. Each phantom had 3 cylinders made of the same dental material: dental amalgam or copper-aluminum alloy. CBCT scans were obtained separately for each of the imaging phantoms using the Picasso-Trio CBCT (Vatech, Hwaseong, Republic of Korea) unit at 4 FOV sizes and 2 voxel sizes. Each imaging phantom was scanned with and without MAR. All images were evaluated in the OnDemand3D software (Cybermed, Seoul, Republic of Korea) and image noise (gray value variability) was calculated as the standard deviation (SD) of the gray values of regions of interest around the dental material cylinders. Data were compared by the Friedman test and Dunn test (α = 0.05). Intraclass correlation coefficient (ICC) was calculated to assess intraobserver reliability. RESULTS: MAR significantly reduced (P < .05) image noise around the dental materials, irrespective of FOV and voxel sizes, with an ICC of 0.997. CONCLUSIONS: The efficacy of MAR was similar for the different FOV and voxel sizes studied. Hence, imaging protocols and the use of MAR algorithm should be based on the selection criteria.