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Flat-panel CT versus 128-slice CT in temporal bone imaging: Assessment of image quality and radiation dose. Eur J Radiol 2018; 106:106-113. [DOI: 10.1016/j.ejrad.2018.07.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/08/2018] [Accepted: 07/14/2018] [Indexed: 11/18/2022]
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352
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Schnutenhaus S, Doering I, Dreyhaupt J, Rudolph H, Luthardt RG. Alveolar ridge preservation with a collagen material: a randomized controlled trial. J Periodontal Implant Sci 2018; 48:236-250. [PMID: 30202607 PMCID: PMC6125670 DOI: 10.5051/jpis.2018.48.4.236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/19/2018] [Indexed: 11/17/2022] Open
Abstract
Purpose Resorption of the alveolar bone is an unavoidable consequence of tooth extraction when appropriate alveolar ridge preservation (ARP) measures are not taken. The objective of this trial was to test the hypothesis that dimensional changes in the alveolar bone after tooth extraction would be reduced by inserting an equine collagen membrane and a collagen cone to fill and seal the alveolus (as ARP), in comparison to extraction with untreated alveoli. Methods In this randomized clinical trial, 31 patients were directly treated with the collagen material after extraction of a tooth from the maxilla (the ARP group). Twenty-nine patients served as the control group. After extraction, no further treatment (i.e., no socket preservation measures) was performed in the control group. Changes in the alveolar process immediately after extraction and after an 8 (±1)-week healing period were evaluated 3-dimensionally. Blinded analyses were performed after superimposing the data from the digitalized impressions and surfaces generated by cone-beam computed tomography. Results Both the ARP and control groups showed a reduction of bone in the alveolar area after tooth extraction. However, significantly less bone resorption was detected in the clinically relevant buccal region in the ARP group. The median bone reduction was 1.18 mm in the ARP group and 5.06 mm in the control group (P=0.03). Conclusions The proposed hypothesis that inserting a combination material comprising a collagen cone and membrane would lead to a difference in alveolar bone preservation can be accepted for the clinically relevant buccal distance. In this area, implantation of the collagen material led to significantly less alveolar bone resorption. German Clinical Trials Register at www.drks.de, DRKS00004769.
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Affiliation(s)
- Sigmar Schnutenhaus
- Private Practice, Hilzingen, Germany.,Department of Prosthetic Dentistry, Center of Dentistry, Ulm University, Ulm, Germany
| | | | - Jens Dreyhaupt
- Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany
| | - Heike Rudolph
- Department of Prosthetic Dentistry, Center of Dentistry, Ulm University, Ulm, Germany
| | - Ralph G Luthardt
- Department of Prosthetic Dentistry, Center of Dentistry, Ulm University, Ulm, Germany
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353
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Nardi C, Calistri L, Grazzini G, Desideri I, Lorini C, Occhipinti M, Mungai F, Colagrande S. Is Panoramic Radiography an Accurate Imaging Technique for the Detection of Endodontically Treated Asymptomatic Apical Periodontitis? J Endod 2018; 44:1500-1508. [PMID: 30154006 DOI: 10.1016/j.joen.2018.07.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/12/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022]
Abstract
INTRODUCTION This study aimed to evaluate the diagnostic accuracy of panoramic radiography (PAN) for the detection of clinically/surgically confirmed apical periodontitis (AP) in root canal-treated teeth using cone-beam computed tomographic (CBCT) imaging as the reference standard. METHODS Two hundred forty patients with endodontically treated AP (diseased group) were detected via CBCT imaging using the periapical index system. They were divided into groups of 20 each according to lesion size (2-4.5 mm and 4.6-7 mm) and anatomic area (incisor, canine/premolar, and molar) in both the upper and lower arches. Another 240 patients with root filling and a healthy periapex (healthy group) were selected. All diseased and healthy patients underwent PAN first and a CBCT scan within 40 days. The periapical index system was also used to assess AP using PAN. Sensitivity, specificity, diagnostic accuracy, positive predictive value, and negative predictive value for PAN images with respect to CBCT imaging were analyzed. The k value was calculated to assess both the interobserver reliability for PAN and the agreement between PAN and CBCT. RESULTS PAN showed low sensitivity (48.8), mediocre negative predictive value (64.7), good diagnostic accuracy (71.3), and high positive predictive value (88.6) and specificity (93.8). Both interobserver reliability for PAN and agreement between PAN and CBCT were moderate (k = 0.58 and 0.42, respectively). The best identified AP was located in the lower canine/premolar and molar areas, whereas the worst identified AP was located in the upper/lower incisor area and upper molar area. CONCLUSIONS PAN showed good diagnostic accuracy, high specificity, and low sensitivity for the detection of endodontically treated AP.
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Affiliation(s)
- Cosimo Nardi
- Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
| | - Linda Calistri
- Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Giulia Grazzini
- Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Isacco Desideri
- Department of Experimental and Clinical Biomedical Sciences, Radiotherapy Unit, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Chiara Lorini
- Department of Health Science, University of Florence, Florence, Italy
| | - Mariaelena Occhipinti
- Department of Experimental and Clinical Medicine, Section of Respiratory Medicine, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Francesco Mungai
- Department of Radiology, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Stefano Colagrande
- Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit, University of Florence, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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354
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Iterative and discrete reconstruction in the evaluation of the rabbit model of osteoarthritis. Sci Rep 2018; 8:12051. [PMID: 30104576 PMCID: PMC6089934 DOI: 10.1038/s41598-018-30334-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/23/2018] [Indexed: 11/09/2022] Open
Abstract
Micro-computed tomography (µCT) is a standard method for bone morphometric evaluation. However, the scan time can be long and the radiation dose during the scan may have adverse effects on test subjects, therefore both of them should be minimized. This could be achieved by applying iterative reconstruction (IR) on sparse projection data, as IR is capable of producing reconstructions of sufficient image quality with less projection data than the traditional algorithm requires. In this work, the performance of three IR algorithms was assessed for quantitative bone imaging from low-resolution data in the evaluation of the rabbit model of osteoarthritis. Subchondral bone images were reconstructed with a conjugate gradient least squares algorithm, a total variation regularization scheme, and a discrete algebraic reconstruction technique to obtain quantitative bone morphometry, and the results obtained in this manner were compared with those obtained from the reference reconstruction. Our approaches were sufficient to identify changes in bone structure in early osteoarthritis, and these changes were preserved even when minimal data were provided for the reconstruction. Thus, our results suggest that IR algorithms give reliable performance with sparse projection data, thereby recommending them for use in µCT studies where time and radiation exposure are preferably minimized.
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355
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Wellenberg RHH, Hakvoort ET, Slump CH, Boomsma MF, Maas M, Streekstra GJ. Metal artifact reduction techniques in musculoskeletal CT-imaging. Eur J Radiol 2018; 107:60-69. [PMID: 30292274 DOI: 10.1016/j.ejrad.2018.08.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/02/2018] [Accepted: 08/11/2018] [Indexed: 01/02/2023]
Abstract
It is known that metal artifacts can be reduced by modifying standard acquisition and reconstruction, by modifying projection data and/or image data and by using virtual monochromatic imaging extracted from dual-energy CT. In this review we focus on the origin of metal artifacts, technical background of commercially available metal artifact reduction (MAR) algorithms and the value of dual-energy CT and MAR software for different metal hardware in current clinical practice. Virtual monochromatic imaging reduces beam-hardening artifacts, where metal artifact reduction software effectively reduces artifacts caused by extensive photon-starvation. Both techniques have their advantages and disadvantages, and the combination of both techniques is often but not always the best solution regarding metal artifact reduction. Advances in prosthetic imaging are reinforced by advances in prosthetic design. Providing implant specific information prior to scanning is important in order to adjust the metal artifact reduction approach, minimize artifacts and optimize image quality and diagnostic value of CT.
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Affiliation(s)
- R H H Wellenberg
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands; Department of Radiology, Isala, Zwolle, The Netherlands.
| | - E T Hakvoort
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands.
| | - C H Slump
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
| | - M F Boomsma
- Department of Radiology, Isala, Zwolle, The Netherlands.
| | - M Maas
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands.
| | - G J Streekstra
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands.
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356
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Wulster KB. Diagnosis of Skeletal Injury in the Sport Horse. Vet Clin North Am Equine Pract 2018; 34:193-213. [DOI: 10.1016/j.cveq.2018.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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357
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Lopes PA, Santaella GM, Lima CAS, Vasconcelos KDF, Groppo FC. Evaluation of soft tissues simulant materials in cone beam computed tomography. Dentomaxillofac Radiol 2018; 48:20180072. [PMID: 30004256 DOI: 10.1259/dmfr.20180072] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate different materials in simulating soft tissues and to analyze the influence of these materials on the mean (MPIV) and standard deviation of pixel intensity values comparing them to a gold-standard in CBCT images. METHODS Images of three piglet heads with their soft tissues intact (gold-standard) and different simulant materials were acquired: ice, modelling wax, and ballistic gelatin, with the same thickness of the original soft tissues. The pixel intensities were measured in dental, bone and soft tissues regions, in the mandible and maxilla, for all the groups. Analysis of variance, Dunnet's, Pearson's and linear regression tests were performed. RESULTS The simulators did not significantly change the MPIV of teeth in comparison with the gold-standard (p = 0.1017). Only ice (p = 0.0156) affected the MPIV of bone. Wax (p = 0.001) and ice (p = 0.0076), but not ballistic gelatin (p = 0.5814), altered the MPIV of soft tissue regions. When assessing the influence of the location (mandible or maxilla) among the simulants, the differences were significant only for the soft tissue regions. Standard deviation was not influenced by simulants (p > 0.05), but ballistic gelatin presented the lower variability. CONCLUSIONS The ballistic gelatin was the best soft tissue simulant since it had the lowest influence on the pixel intensity values for all regions.
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Affiliation(s)
- Priscila A Lopes
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Gustavo M Santaella
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Carlos Augusto S Lima
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Karla de Faria Vasconcelos
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Francisco C Groppo
- Department of Physiological Sciences, University of Campinas, Piracicaba, São Paulo, Brazil
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358
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Barba L, Berrocal AL, Hidalgo A. Uses of cone-beam computed tomography in San José, Costa Rica. Imaging Sci Dent 2018; 48:103-109. [PMID: 29963481 PMCID: PMC6015925 DOI: 10.5624/isd.2018.48.2.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/19/2018] [Accepted: 05/02/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose To analyze cone-beam computed tomography (CBCT) use, indications, and exposure parameters in San José, Costa Rica. Materials and Methods A cross-sectional study was performed. All CBCT examinations over a period of 6 months at 2 radiological centers in San José, Costa Rica were evaluated. The examinations were performed with Veraview EPOC X550 and Veraviewepocs 3D R100 equipment. The patients' age and sex, clinical indication for CBCT, region of interest (ROI), repeat examinations, specialty of the referring dentist, field-of-view (FOV), tube voltage (kV), tube current (mA), and radiation dose (µGy) were evaluated. Patients were classified by age as children (≤12 years), adolescents (13–18 years), and adults (≥19 years). Results The mean age of the 526 patients was 49.4 years. The main indications were implant dentistry and dental trauma. The most frequent ROIs were posterior, while anterior ROIs were much less common. The highest percentage of repeat examinations was in children. Fifty-six percent of the referring dentists were specialists. The most commonly used FOV was small. The mean tube voltage and current were 79.8 kV and 7.4 mA for Veraview EPOC X550 and 89.9 kV and 6 mA for Veraviewepocs 3D R100, respectively. The mean doses for children, adolescents, and adults were 6.9 µGy, 8.4 µGy, and 7.8 µGy, respectively. Conclusion Although CBCT was most commonly used in adults for implant dentistry, most repeat examinations were in children, and the highest mean dose was in adolescents. Additional dose optimization efforts should be made by introducing low-dose protocols for children and adolescents.
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Affiliation(s)
- Lucía Barba
- Specialization Program in Oral and Maxillofacial Imaging, Graduate School, Universidad de Talca, Talca, Chile
| | - Ana Luisa Berrocal
- Department of Diagnostic and Surgical Sciences, Faculty of Dentistry, Universidad de Costa Rica, San José, Costa Rica
| | - Alejandro Hidalgo
- Specialization Program in Oral and Maxillofacial Imaging, Graduate School, Universidad de Talca, Talca, Chile
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359
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Abstract
This article describes digital radiographic imaging and analysis from the basics of image capture to examples of some of the most advanced digital technologies currently available. The principles underlying the imaging technologies are described to provide a better understanding of their strengths and limitations.
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Affiliation(s)
- Douglas C Yoon
- Research and Development, XDR Radiology, 11300 West Olympic Boulevard, Suite 710, Los Angeles, CA 90064, USA.
| | - André Mol
- Department of Diagnostic Sciences, School of Dentistry, University of North Carolina at Chapel Hill, 385 South Columbia Street, Chapel Hill, NC 27599, USA
| | - Douglas K Benn
- Department of Diagnostic Sciences, Creighton University School of Dentistry, 2802 Webster Street, Omaha, NE 68178, USA
| | - Erika Benavides
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, 2029F, 1011 North University Avenue, Ann Arbor, MI 49109-1078, USA
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Spin-Neto R, Matzen LH, Schropp LW, Sørensen TS, Wenzel A. An ex vivo study of automated motion artefact correction and the impact on cone beam CT image quality and interpretability. Dentomaxillofac Radiol 2018; 47:20180013. [PMID: 29537303 PMCID: PMC6196041 DOI: 10.1259/dmfr.20180013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/02/2018] [Accepted: 03/08/2018] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess the impact of head motion artefacts and an automated artefact-correction system on cone beam CT (CBCT) image quality and interpretability for simulated diagnostic tasks. METHODS A partially dentate human skull was mounted on a robot simulating four types of head movement (anteroposterior translation, nodding, lateral rotation, and tremor), at three distances (0.75, 1.5, and 3 mm) based on two movement patterns (skull returning/not returning to the initial position). Two diagnostic tasks were simulated: dental implant planning and detection of a periapical lesion. Three CBCT units were used to examine the skull during the movements and no-motion (control): Cranex 3Dx (CRA), Orthophos SL 3D (ORT), and X1 without (X1wo) and with (X1wi) an automated motion artefact-correction system. For each diagnostic task, 88 examinations were performed. Three observers, blinded to unit and movement, scored image quality: presence of stripe artefacts (present/absent), overall unsharpness (present/absent), and image interpretability (interpretable/non-interpretable). κ statistics assessed interobserver agreement, and descriptive statistics summarized the findings. RESULTS Interobserver agreement for image interpretability was good (average κ = 0.68). Regarding dental implant planning, X1wi images were interpretable by all observers, while for the other units mainly the cases with tremor were non-interpretable. Regarding detection of a periapical lesion, besides tremor, most of the 3 mm movements based on the "not returning" pattern were also non-interpretable for CRA, ORT, and X1wo. For X1wi, two observers scored 1.5 mm tremor and one observer scored 3 mm tremor as non-interpretable. CONCLUSIONS The automated motion artefact-correction system significantly enhanced CBCT image quality and interpretability.
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Affiliation(s)
- Rubens Spin-Neto
- Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Louise H Matzen
- Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Lars W Schropp
- Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | | | - Ann Wenzel
- Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
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361
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Wanderley VA, Freitas DQ, Haiter-Neto F, Oliveira ML. Influence of Tooth Orientation on the Detection of Vertical Root Fracture in Cone-beam Computed Tomography. J Endod 2018; 44:1168-1172. [DOI: 10.1016/j.joen.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/18/2018] [Accepted: 04/02/2018] [Indexed: 10/14/2022]
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362
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Freitas DQ, Fontenele RC, Nascimento EHL, Vasconcelos TV, Noujeim M. Influence of acquisition parameters on the magnitude of cone beam computed tomography artifacts. Dentomaxillofac Radiol 2018; 47:20180151. [PMID: 29916722 DOI: 10.1259/dmfr.20180151] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
AIM To evaluate the influence of kilovoltage (kVp) and metal artifact reduction tool (MAR) on the magnitude of cone beam CT (CBCT) artifacts. METHODS A titanium and zirconia implants were inserted alternately in a posterior region of a mandible. CBCT exams were acquired with ProMax 3D (Planmeca Oy, Helsinki, Finland) and Picasso Trio machines (Vatech, Hwaseong, South Korea) using 70 kVp, 80 kVp and 90 kVp with and without MAR activation. The other exposure factors remained fixed at 5mA, field of view 80 × 50 mm and voxel 0.20 mm. The scans were performed before and after the insertion of the implants. Regions of interest were determined in different distances from the artifact production area (15, 25 and 35 mm) in an axial image, in which standard deviation (SD) of grayscale values was measured and contrast-to-noise ratio (CNR) was calculated. Analysis of variance was used to compare the data. RESULTS Overall, in cases where the artifact was pronounced, MAR was efficient in reducing SD values. MAR also improved the CNR of ProMax images, but did not affect the Picasso images. Additionally, the higher was the kVp, the lower was the SD value and the higher was the CNR in both machines. CONCLUSION In both machines, increasing kVp and MAR are effective in decreasing the CBCT artifacts in all their magnitude when they are pronounced. Therefore, the professionals should choose one of those options or even both considering the purpose of the CBCT imaging and radiation dose for the patient.
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Affiliation(s)
- Deborah Queiroz Freitas
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Limeira , Brazil
| | - Rocharles Cavalcante Fontenele
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Limeira , Brazil
| | | | | | - Marcel Noujeim
- 3 Department of Comprehensive Dentistry, Division of Oral and Maxillofacial Radiology, University of Texas Health Science Center at San Antonio , San Antonio, TX , United States
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363
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Liedke GS, Spin-Neto R, da Silveira HED, Schropp L, Stavropoulos A, Wenzel A. Accuracy of detecting and measuring buccal bone thickness adjacent to titanium dental implants-a cone beam computed tomography in vitro study. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 126:432-438. [PMID: 30126809 DOI: 10.1016/j.oooo.2018.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/16/2018] [Accepted: 06/11/2018] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The aim of this study was to assess the accuracy of detecting and measuring buccal bone thickness (BBT) adjacent to titanium implants in cone beam computed tomography (CBCT) images. STUDY DESIGN Titanium implants (1, 2, or 3), abutments, and metal-ceramic crowns were inserted into 40 bone blocks with various BBTs. CBCT images were acquired in various settings: Voxel sizes (0.2 and 0.13 mm) and reconstruction section thicknesses (2.0 and 5.0 mm) were assessed by 3 examiners. True BBT was measured in digital photographs of the bone blocks. Buccal bone detection was evaluated by sensitivity and specificity. BBT was evaluated by 1-way analysis of variance (ANOVA) between the true and the CBCT measurements and by calculating the difference between the true measurement and the CBCT measurement (Di-BBT). RESULTS Detection of buccal bone exhibited high sensitivity (0.86-1) and low specificity (0.14-1). More implants in the field of view, large voxel size, and thick image reconstruction sections had a negative impact on buccal bone detection. ANOVA showed statistically significantly larger BBT for the CBCT measurements in all settings (1.07-1.21 mm) compared with the true measurements (0.85 mm). Di-BBT was mostly within 0.5 mm. CONCLUSIONS BBT adjacent to titanium implants is overestimated when evaluated on CBCT cross-sectional images.
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Affiliation(s)
- Gabriela Salatino Liedke
- Adjunct Professor, Oral Radiology, Department of Stomatology, School of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Brazil.
| | - Rubens Spin-Neto
- Associate Professor, Oral Radiology, Section of Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Heloisa Emilia Dias da Silveira
- Professor, Department of Surgery and Orthopedics, School of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Lars Schropp
- Associate Professor, Oral Radiology, Section of Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Andreas Stavropoulos
- Professor, Dept. of Periodontology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Ann Wenzel
- Professor, Section of Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
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Waltrich N, Sawall S, Maier J, Kuntz J, Stannigel K, Lindenberg K, Kachelrieß M. Effect of detruncation on the accuracy of Monte Carlo-based scatter estimation in truncated CBCT. Med Phys 2018; 45:3574-3590. [PMID: 29888791 DOI: 10.1002/mp.13041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 05/20/2018] [Accepted: 06/04/2018] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study is to investigate the necessity of detruncation for scatter estimation of truncated cone-beam CT (CBCT) data and to evaluate different detruncation algorithms. Scattered radiation results in some of the most severe artifacts in CT and depends strongly on the size and the shape of the scanned object. Especially in CBCT systems the large cone-angle and the small detector-to-isocenter distance lead to a large amount of scatter detected, resulting in cupping artifacts, streak artifacts, and inaccurate CT-values. If a small field of measurement (FOM) is used, as it is often the case in CBCT systems, data are truncated in longitudinal and lateral direction. Since only truncated data are available as input for the scatter estimation, the already challenging correction of scatter artifacts becomes even more difficult. METHODS The following detruncation methods are compared and evaluated with respect to scatter estimation: constant detruncation, cosine detruncation, adaptive detruncation, and prior-based detruncation using anatomical data from a similar phantom or patient, also compared to the case where no detruncation was performed. Each of the resulting, detruncated reconstructions serve as input volume for a Monte Carlo (MC) scatter estimation and subsequent scatter correction. An evaluation is performed on a head simulation, measurements of a head phantom and a patient using a dental CBCT geometry with a FOM diameter of 11 cm. Additionally, a thorax phantom is measured to assess performance in a C-Arm geometry with a FOM of up to 20 cm. RESULTS If scatter estimation is based on simple detruncation algorithms like a constant or a cosine detruncation scatter is estimated inaccurately, resulting in incorrect CT-values as well as streak artifacts in the corrected volume. For the dental CBCT phantom measurement CT-values for soft tissue were corrected from -204 HU (no scatter correction) to -87 HU (no detruncation), -218 HU (constant detruncation), -141 HU (cosine detruncation), -91 HU (adaptive detruncation), -34 HU (prior-based detruncation using a different prior) and -24 HU (prior-based detruncation using the identical prior) for a reference value of -26 HU measured in slit scan mode. In all cases the prior-based detruncation results in the best scatter correction, followed by the adaptive detruncation, as these algorithms provide a rather accurate model of high-density structures outside the FOM, compared to a simple constant or a cosine detruncation. CONCLUSIONS Our contribution is twofold: first we give a comprehensive comparison of various detruncation methods for the purpose of scatter estimation. We find that the choice of the detruncation method has a significant influence on the quality of MC-based scatter correction. Simple or no detruncation is often insufficient for artifact removal and results in inaccurate CT-values. On the contrary, prior-based detruncation can achieve a high CT-value accuracy and nearly artifact-free volumes from truncated CBCT data when combined with other state-of-the-art artifact corrections. Secondly, we show that prior-based detruncation is effective even with data from a different patient or phantom. The fact that data completion does not require data from the same patient dramatically increases the applicability and usability of this scatter estimation.
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Affiliation(s)
- Nadine Waltrich
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Department of Physics and Astronomy, Ruprecht-Karls-University, Im Neuenheimer Feld 226, Heidelberg, Germany
| | - Stefan Sawall
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Department of Physics and Astronomy, Ruprecht-Karls-University, Im Neuenheimer Feld 226, Heidelberg, Germany
| | - Joscha Maier
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Department of Physics and Astronomy, Ruprecht-Karls-University, Im Neuenheimer Feld 226, Heidelberg, Germany
| | - Jan Kuntz
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Medical Faculty, Ruprecht-Karls-University, Im Neuenheimer Feld 672, Heidelberg, Germany
| | - Kai Stannigel
- Sirona Dental Systems GmbH, Fabrikstraße 31, 64625, Bensheim, Germany
| | - Kai Lindenberg
- Sirona Dental Systems GmbH, Fabrikstraße 31, 64625, Bensheim, Germany
| | - Marc Kachelrieß
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
- Medical Faculty, Ruprecht-Karls-University, Im Neuenheimer Feld 672, Heidelberg, Germany
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365
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Jacobs R, Salmon B, Codari M, Hassan B, Bornstein MM. Cone beam computed tomography in implant dentistry: recommendations for clinical use. BMC Oral Health 2018; 18:88. [PMID: 29764458 PMCID: PMC5952365 DOI: 10.1186/s12903-018-0523-5] [Citation(s) in RCA: 201] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 03/26/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems. METHODS Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided. RESULTS The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 μm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 μm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions. CONCLUSIONS Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.
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Affiliation(s)
- Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium. .,Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium. .,Department of Dental Medicine (DENTMED), Karolinska Institutet, Stockholm, Sweden.
| | - Benjamin Salmon
- EA2496, Orofacial Pathologies, Imaging and Biotherapies Lab, Dental School Paris Descartes University, Sorbonne Paris Cité, Paris, France.,Department of Odontology, AP-HP, Nord Val de Seine Hospital (Bretonneau), Paris, France
| | - Marina Codari
- Unit of Radiology, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Bassam Hassan
- Department of Oral Function and Restorative Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Research Institute MOVE, 1081 LA, Amsterdam, The Netherlands
| | - Michael M Bornstein
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven, Kapucijnenvoer 33, 3000, Leuven, Belgium.,Applied Oral Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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366
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Fontenele RC, Nascimento EH, Vasconcelos TV, Noujeim M, Freitas DQ. Magnitude of cone beam CT image artifacts related to zirconium and titanium implants: impact on image quality. Dentomaxillofac Radiol 2018; 47:20180021. [PMID: 29668300 DOI: 10.1259/dmfr.20180021] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To evaluate the magnitude of artifacts related to titanium and zirconium implants at different distances and angulations and their impact on cone beam CT(CBCT) image quality. METHODS CBCT images were obtained before and after the insertion of titanium and zirconium implants in a mandible on different CBCT units: Picasso Trio, ProMax 3D and 3D Accuitomo 80. Artifact was assessed by measuring the standard deviation (SD) of gray values and contrast-to-noise ratio (CNR) of 11 regions of interest (ROIs) at different distances (1.5 cm, 2.5 cm and 3.5 cm) and angulations (65°, 90°, 115° and 140°) from implant region. RESULTS For titanium images, SD values did not differ from those of images without implant in all ROIs; however, some effect occurred in Picasso images as higher values were observed in ROIs closer to the implant (p < 0.05). Zirconium images showed higher SD values than the others in some ROIs for Picasso and ProMax (p < 0.05). In ProMax, the difference was observed even in the farthest ROIs from the implant. CNR values were not influenced by the ROI in Picasso, but presented lower values in ROIs closer to the zirconium implant for ProMax and Accuitomo. CONCLUSIONS The quantity and magnitude of artifacts in CBCT are influenced by the type of implant and CBCT unit. Although they are more pronounced in regions closer to the implant and located at 90° in relation to the mandibular long axis, they can reach as far as 3.5 cm from the artifact-generator object.
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Affiliation(s)
- Rocharles C Fontenele
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil
| | - Eduarda Hl Nascimento
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil
| | - Taruska V Vasconcelos
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil
| | - Marcel Noujeim
- 2 Department of Comprehensive Dentistry, Division of Oral and Maxillofacial Radiology, University of Texas Health Science Center , San Antonio, TX , USA
| | - Deborah Q Freitas
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba, São Paulo , Brazil
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367
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Zhang W, Foss K, Wang BY. A retrospective study on molar furcation assessment via clinical detection, intraoral radiography and cone beam computed tomography. BMC Oral Health 2018; 18:75. [PMID: 29724208 PMCID: PMC5934848 DOI: 10.1186/s12903-018-0544-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/27/2018] [Indexed: 11/29/2022] Open
Abstract
Background Accurate determination of bone loss at the molar furcation region by clinical detection and intraoral radiograph is challenging in many instances. Cone beam computed tomography (CBCT) is expected to open a new horizon in periodontal assessment. The purpose of this study was to compare and correlate accuracy of molar furcation assessment via clinical detection, intraoral radiography and CBCT images. Methods Eighty-three patients with chronic periodontitis who had existing CBCT scans were included. Furcation involvement was assessed on maxillary and mandibular first molars. Periodontal charts (modified Glickman’s classification), intraoral (periapical and/or bitewing) radiographs (recorded as presence or absence) and axial CBCT reconstructions were used to evaluate furcation involvement on buccal and palatal/lingual sites. The correlation of furcation assessment by the three methods was evaluated by Pearson analysis. Results There were significant correlations (p < 0.05) between clinical detection and intraoral radiography, clinical detection and CBCT, as well as intraoral radiography and CBCT at all the measured sites (r values range between 0.230 to 0.644). CBCT generally exhibited higher correlation with clinical detection relative to intraoral radiography, especially at distal palatal side of maxillary first molar (p < 0.05). In addition, CBCT provided more accurate assessment, with bone loss measurement up to 2 decimals in millimeters, whereas clinical detection had 3 classes and the intraoral radiographs usually only detected the presence of furcation involvement in Glickman Class 2 and 3. Conclusions This study validates that CBCT is a valuable tool in molar furcation assessment in addition to clinical detection and intraoral radiography.
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Affiliation(s)
- Wenjian Zhang
- Department of Diagnostic & Biomedical Sciences, University of Texas School of Dentistry at Houston, 7500 Cambridge Street, Houston, TX, 77054, USA.
| | - Keagan Foss
- University of Texas School of Dentistry at Houston, 7500 Cambridge Street, Houston, TX, 77054, USA
| | - Bing-Yan Wang
- Department of Periodontics & Dental Hygiene, University of Texas School of Dentistry at Houston, 7500 Cambridge Street, Houston, TX, 77054, USA
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368
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Liu J, Chen HY, DoDo H, Yousef H, Firestone AR, Chaudhry J, Johnston WM, Lee DJ, Emam HA, Kim DG. Efficacy of Cone-Beam Computed Tomography in Evaluating Bone Quality for Optimum Implant Treatment Planning. IMPLANT DENT 2018; 26:405-411. [PMID: 28125517 DOI: 10.1097/id.0000000000000542] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE This study examined (1) if cone-beam computed tomography (CBCT) can determine relative differences in bone mineral density distribution using clinical images of patients' mandibular bone and (2) if the relative differences can be used to detect the effects of sex and age on bone mineral density distribution. MATERIALS AND METHODS Sixty-six clinical CBCT images from patients (36 females and 30 males) of 3 age groups (40, 50, and 60 years) were identified. Alveolar (AB) and basal cortical bone (CB) regions were digitally isolated. A histogram of gray levels, which are proportional to degrees of bone mineralization, was obtained from each region. Mean, variability (SD and coefficient of variation), and percentage differences of gray level parameters between AB and basal CBs were computed. RESULTS Significant sex differences in gray level variability were observed within the postmenopausal age group (P < 0.042). CONCLUSION These findings suggest that clinical CBCT images can be a valuable tool in providing information on bone quality, which is an important criterion for optimum planning for dental implant placement.
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Affiliation(s)
- Jie Liu
- *Private Practice, Former Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. †Undergraduate Student, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. ‡Predoctoral Student, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. §Master Student, Clinical and Translational Science, College of Medicine, Ohio State University, Columbus, OH. ¶Associate Professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. ‖Clinical Associate Professor, Department of Oral Pathology, Medicine and Radiology, School of Dentistry, Indiana University, Indianapolis, IN. #Professor Emeritus, Division of General Practice and Materials Science, College of Dentistry, Ohio State University, Columbus, OH. **Assistant Professor, Division of Restorative Sciences and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH. ††Division of Oral and Maxillofacial Surgery, College of Dentistry, The Ohio State University, Columbus, OH
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369
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A Novel Method for Characterizing Beam Hardening Artifacts in Cone-beam Computed Tomographic Images. J Endod 2018; 44:869-874. [DOI: 10.1016/j.joen.2018.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 01/26/2018] [Accepted: 02/04/2018] [Indexed: 11/21/2022]
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370
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Schnutenhaus S, Gröller S, Luthardt RG, Rudolph H. Accuracy of the match between cone beam computed tomography and model scan data in template-guided implant planning: A prospective controlled clinical study. Clin Implant Dent Relat Res 2018; 20:541-549. [PMID: 29691987 DOI: 10.1111/cid.12614] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 01/27/2018] [Accepted: 03/17/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Template-guided implant placement is a method for optimal implant positioning from a prosthetic and surgical viewpoint. The treatment planning is based on three-dimensional X-ray data and model scan data, as well as on prosthetic planning (set-up). These data are matched (superimposed) with the aid of an X-ray template or by manual matching without special referencing. PURPOSE The objective of this prospective controlled clinical study was to determine and compare the accuracy of the match with and without an additional X-ray template. MATERIALS AND METHODS The DICOM data of the cone beam computed tomography (CBCT) were converted into surface data sets and then superimposed on model scan data using three different methods (manually, based on an X-ray template, or semi-automatically with computer assistance). The mean deviations between these results of these matching methods were investigated. RESULTS The procedures achieved a matching accuracy of 0.2 mm on average. This corresponds to the resolution of the CBCT (0.2 voxels). Further studies are necessary to verify the procedure even for patients with few (0-4) residual teeth. CONCLUSION In the presence of a sufficient number of residual teeth, the manual matching of model scan data with CBCT data is sufficiently accurate for implant planning and template-guided implementation. The results of the present study suggest that X-ray templates can be dispensed with saving the patient a substantial amount of time and money.
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Affiliation(s)
- Sigmar Schnutenhaus
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Germany and Private practice, Hilzingen, Germany
| | - Sebastian Gröller
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Germany and Private practice, Hilzingen, Germany
| | - Ralph G Luthardt
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Germany and Private practice, Hilzingen, Germany
| | - Heike Rudolph
- Department of Prosthetic Dentistry, Center of Dentistry, University of Ulm, Germany and Private practice, Hilzingen, Germany
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371
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Lim LZ, Padilla RJ, Reside GJ, Tyndall DA. Comparing panoramic radiographs and cone beam computed tomography: Impact on radiographic features and differential diagnoses. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 126:S2212-4403(18)30888-5. [PMID: 29748039 DOI: 10.1016/j.oooo.2018.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVES The aims of this study were to determine whether lesion features appear differently on panoramic radiography (PAN) and cone beam computed tomography (CBCT), and whether the use of CBCT affects diagnostic accuracy and observers' confidence in comparison with PAN. STUDY DESIGN Three oral and maxillofacial radiologists reviewed 33 sets of PAN images and CBCT volumes of biopsy-proven lesions. They described 12 different lesion features and provided up to 3 ranked differential diagnoses, as well as their confidence with respect to those diagnoses. Their confidence was weighted by the rank at which the correct diagnosis was provided. RESULTS Odds ratios (ORs) were statistically significant for border definition (OR = 5.45; P = .004), continuity of border cortication (OR = 0.34; P = .035), effect on neurovascular canals (OR = 6.38; P = .043), expansion (OR = 18.56; P < .001), cortical thinning (OR = 30.22; P < .001), and cortical destruction (OR = 9.80; P < .001). There was no association between the 2 modalities and the rank at which the correct differential diagnoses were made or the observers' weighted confidence. CONCLUSIONS Before acquiring a CBCT scan to aid in the diagnosis of an intraosseous lesion, clinicians should consider the diagnostic information that is expected to be gained. In this study, although there were differences between PAN and CBCT with respect to some lesion features, CBCT did not help improve diagnostic accuracy.
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Affiliation(s)
- Li Zhen Lim
- Department of Diagnostic Sciences, University of North Carolina at Chapel Hill School of Dentistry, Chapel Hill, NC, USA.
| | - Ricardo J Padilla
- Department of Diagnostic Sciences, University of North Carolina at Chapel Hill School of Dentistry, Chapel Hill, NC, USA
| | - Glenn J Reside
- Department of Oral and Maxillofacial Surgery, University of North Carolina at Chapel Hill School of Dentistry, Chapel Hill, NC, USA
| | - Donald A Tyndall
- Department of Diagnostic Sciences, University of North Carolina at Chapel Hill School of Dentistry, Chapel Hill, NC, USA
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372
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Candemil AP, Salmon B, Freitas DQ, Ambrosano GM, Haiter-Neto F, Oliveira ML. Metallic materials in the exomass impair cone beam CT voxel values. Dentomaxillofac Radiol 2018; 47:20180011. [PMID: 29582689 DOI: 10.1259/dmfr.20180011] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVES To assess the influence of artefacts arising from metallic materials in the exomass on cone beam CT (CBCT) voxel values. METHODS CBCT scans were taken of a phantom composed of 16 tubes filled with a homogeneous hyperdense solution and metallic materials of different compositions (titanium, cobalt-chromium and amalgam) and numbers (one, two and three). The phantom was centred in a 5 × 5 cm field of view such that the metallic materials were located in the exomass, using three CBCT units. Voxel values were obtained from the 16 homogeneous areas and averaged. Also, standard deviation was calculated to measure voxel value variability. Analysis of variance in a factorial scheme with additional treatment 3 × 3 + 3 (material × number + control) was performed, followed by Tukey's test for multiple comparisons, and Dunnett's test for comparisons with the control groups, at a level of significance of 5%. RESULTS Metallic material in the exomass significantly reduced the mean voxel value in the CS9300 and Picasso Trio units, and increased voxel value variability in all CBCT units. Amalgam was the material that induced significantly greater reduction of the mean voxel value in the CS9300 and Picasso Trio units, and significantly greater increase in the NewTom Giano. Voxel value variability was significantly greater for amalgam in all conditions. The presence of one cylinder induced significantly less pronounced effects on the mean voxel value and voxel value variability. CONCLUSIONS Artefacts arising from metallic materials in the exomass have a negative influence on CBCT voxel values.
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Affiliation(s)
- Amanda P Candemil
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
| | - Benjamin Salmon
- 2 Department of Dental Medicine, Bretonneau Hospital, HUPNVS, AP-HP , Paris , France.,3 EA 2496 - Orofacial Pathologies, Imaging and Biotherapies Lab, Sorbonne Paris Cité - Paris Descartes University. , Paris , France
| | - Deborah Q Freitas
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
| | - Glaucia Mb Ambrosano
- 4 Department of Community Dentistry, Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
| | - Francisco Haiter-Neto
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
| | - Matheus L Oliveira
- 1 Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas , Piracicaba , Brazil
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373
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Queiroz PM, Santaella GM, Groppo FC, Freitas DQ. Metal artifact production and reduction in CBCT with different numbers of basis images. Imaging Sci Dent 2018; 48:41-44. [PMID: 29581948 PMCID: PMC5863018 DOI: 10.5624/isd.2018.48.1.41] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/25/2018] [Accepted: 01/31/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose To evaluate the effect of different numbers of basis images and the use of metal artifact reduction (MAR) on the production and reduction of artifacts in cone-beam computed tomography images. Materials and Methods An acrylic resin phantom with a metal alloy sample was scanned, with 450 or 720 basis images and with or without MAR. Standard deviation values for the test areas (around the metal object) were obtained as a way of measuring artifact production. Two-way analysis of variance was used with a 5% significance level. Results There was no significant difference in artifact production among the images obtained with different numbers of basis images without MAR (P=.985). MAR significantly reduced artifact production in the test areas only in the protocol using 720 basis images (P=.017). The protocol using 450 basis images with MAR showed no significant difference in artifact production when compared to the protocol using 720 basis images with MAR (P=.579). Conclusion Protocols with a smaller number of basis images and with MAR activated are preferable for minimizing artifact production in tomographic images without exposing the patient to a greater radiation dose.
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Affiliation(s)
- Polyane Mazucatto Queiroz
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Gustavo Machado Santaella
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Francisco Carlos Groppo
- Department of Physiological Sciences, Area of Pharmacology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
| | - Deborah Queiroz Freitas
- Department of Oral Diagnosis, Area of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil
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374
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MacKay RI. Image Guidance for Proton Therapy. Clin Oncol (R Coll Radiol) 2018; 30:293-298. [PMID: 29551567 DOI: 10.1016/j.clon.2018.02.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 01/31/2018] [Accepted: 02/04/2018] [Indexed: 11/24/2022]
Abstract
Image-guided radiotherapy has an established role in all forms of radiotherapy treatment delivery. Proton therapy seeks to deliver superior dose distributions through utilising the Bragg peak to target tumour and avoid sensitive normal tissue. The Bragg peak and sharp falloff in dose delivered by proton therapy necessitate careful treatment planning and treatment delivery. The dose distribution delivered by proton therapy is particularly sensitive to uncertainty in the prediction of proton range during treatment planning and deviations from the planned delivery during the course of the fractionated treatment. Realising the superior dose distribution of proton therapy requires increased diligence and image guidance has a key role in ensuring that treatments are planned and delivered. This article will outline the current status of image guidance for proton therapy, particularly highlighting differences with regard to high-energy X-ray therapy, and will look at a number of future improvements in image-guided proton therapy.
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Affiliation(s)
- R I MacKay
- Manchester Academic Health Science Centre, Institute of Cancer Sciences, Manchester Cancer Research Centre (MCRC), The University of Manchester, Manchester, UK; Radiotherapy Related Research, The Christie NHS Foundation Trust, Manchester, UK.
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375
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Registration area and accuracy when integrating laser-scanned and maxillofacial cone-beam computed tomography images. Am J Orthod Dentofacial Orthop 2018; 153:355-361. [PMID: 29501110 DOI: 10.1016/j.ajodo.2017.06.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 06/01/2017] [Accepted: 06/01/2017] [Indexed: 11/23/2022]
Abstract
INTRODUCTION The purpose of this study was to examine changes in registration accuracy after including occlusal surface and incisal edge areas in addition to the buccal surface when integrating laser-scanned and maxillofacial cone-beam computed tomography (CBCT) dental images. METHODS CBCT scans and maxillary dental casts were obtained from 30 patients. Three methods were used to integrate the images: R1, only the buccal and labial surfaces were used; R2, the incisal edges of the anterior teeth and the buccal and distal marginal ridges of the second molars were used; and R3, labial surfaces, including incisal edges of anterior teeth, and buccal surfaces, including buccal and distal marginal ridges of the second molars, were used. Differences between the 2 images were evaluated by color-mapping methods and average surface distances by measuring the 3-dimensional Euclidean distances between the surface points on the 2 images. RESULTS The R1 method showed more discrepancies between the laser-scanned and CBCT images than did the other methods. The R2 method did not show a significant difference in registration accuracy compared with the R3 method. CONCLUSIONS The results of this study indicate that accuracy when integrating laser-scanned dental images into maxillofacial CBCT images can be increased by including occlusal surface and incisal edge areas as registration areas.
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376
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Chaurand P, Liu W, Borschneck D, Levard C, Auffan M, Paul E, Collin B, Kieffer I, Lanone S, Rose J, Perrin J. Multi-scale X-ray computed tomography to detect and localize metal-based nanomaterials in lung tissues of in vivo exposed mice. Sci Rep 2018. [PMID: 29535369 PMCID: PMC5849692 DOI: 10.1038/s41598-018-21862-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In this methodological study, we demonstrated the relevance of 3D imaging performed at various scales for the ex vivo detection and location of cerium oxide nanomaterials (CeO2-NMs) in mouse lung. X-ray micro-computed tomography (micro-CT) with a voxel size from 14 µm to 1 µm (micro-CT) was combined with X-ray nano-computed tomography with a voxel size of 63 nm (nano-CT). An optimized protocol was proposed to facilitate the sample preparation, to minimize the experimental artifacts and to optimize the contrast of soft tissues exposed to metal-based nanomaterials (NMs). 3D imaging of the NMs biodistribution in lung tissues was consolidated by combining a vast variety of techniques in a correlative approach: histological observations, 2D chemical mapping and speciation analysis were performed for an unambiguous detection of NMs. This original methodological approach was developed following a worst-case scenario of exposure, i.e. high dose of exposure with administration via intra-tracheal instillation. Results highlighted both (i) the non-uniform distribution of CeO2-NMs within the entire lung lobe (using large field-of-view micro-CT) and (ii) the detection of CeO2-NMs down to the individual cell scale, e.g. macrophage scale (using nano-CT with a voxel size of 63 nm).
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Affiliation(s)
- Perrine Chaurand
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France. .,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France.
| | - Wei Liu
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Daniel Borschneck
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Clément Levard
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Mélanie Auffan
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Emmanuel Paul
- INSERM, Equipe 04, U955, Creteil, France.,Univ Paris Est Creteil, IMRB, Fac Med, DHU A TVB, Creteil, France
| | - Blanche Collin
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Isabelle Kieffer
- OSUG-FAME, UMS 832 CNRS-Univ. Grenoble Alpes, F-38041, Grenoble, France
| | - Sophie Lanone
- INSERM, Equipe 04, U955, Creteil, France.,Univ Paris Est Creteil, IMRB, Fac Med, DHU A TVB, Creteil, France
| | - Jérôme Rose
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Jeanne Perrin
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,Univ Avignon, Inst Mediterraneen Biodiversite & Ecol Marine & C, Aix Marseille Univ, CNRS, IRD, Marseille, France.,AP HM La Conception, CECOS, Lab Reprod Biol, Dept Gynecol Obstet & Reprod Med, Pole Femmes Parents Enfants, Marseille, France
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377
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De Seta D, Mancini P, Russo FY, Torres R, Mosnier I, Bensimon JL, De Seta E, Heymann D, Sterkers O, Bernardeschi D, Nguyen Y. 3D curved multiplanar cone beam CT reconstruction for intracochlear position assessment of straight electrodes array. A temporal bone and clinical study. ACTA OTORHINOLARYNGOLOGICA ITALICA 2018; 36:499-505. [PMID: 27600104 PMCID: PMC5317130 DOI: 10.14639/0392-100x-1279] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 06/19/2016] [Indexed: 11/23/2022]
Abstract
A retrospective review of post-op cone beam CT (CBCT) of 8 adult patients and 14 fresh temporal bones that underwent cochlear implantation with straight flexible electrodes array was performed to determine if the position of a long and flexible electrodes array within the cochlear scalae could be reliably assessed with CBCT. An oto-radiologist and two otologists examined the images and assessed the electrodes position. The temporal bone specimens underwent histological analysis for confirm the exact position. The position of the electrodes was rated as scala tympani, scala vestibule, or intermediate position for the electrodes at 180°, 360° and for the apical electrode. In the patient group, for the electrodes at 180° all observers agreed for scala tympani position except for 1 evaluation, while a discrepancy in 3 patients both for the 360° and for the apical electrode assessment were found. In five temporal bones the evaluations were in discrepancy for the 180° electrode, while at 360° a disagreement between raters on the scalar positioning was seen in six temporal bones. A higher discrepancy between was found in assessment of the scalar position of the apical electrode (average pairwise agreement 45.4%, Fleiss k = 0.13). A good concordance was found between the histological results and the consensus between raters for the electrodes in the basal turn, while low agreement (Cohen's k 0.31, pairwise agreement 50%) was found in the identification of the apical electrode position confirming the difficulty to correct identify the electrode position in the second cochlear turn in temporal bones. In conclusion, CBCT is a reliable radiologic exam to correctly evaluate the position of a lateral wall flexible array in implanted patients using the proposed imaging reconstruction method, while some artefacts impede exact evaluation of the position of the apical electrode in temporal bone and other radiological techniques should be preferred in ex vivo studies.
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Affiliation(s)
- D De Seta
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France.,Department of Sense Organs, Sapienza University of Rome, Italy
| | - P Mancini
- Department of Sense Organs, Sapienza University of Rome, Italy
| | - F Y Russo
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France.,Department of Sense Organs, Sapienza University of Rome, Italy
| | - R Torres
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France
| | - I Mosnier
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France
| | - J L Bensimon
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France
| | - E De Seta
- Department of Sense Organs, Sapienza University of Rome, Italy
| | - D Heymann
- Inserm, UMR 957, Laboratory of Pathophysiology of Bone Resorption and Therapy of Primary Bone Tumours, Nantes, France
| | - O Sterkers
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France
| | - D Bernardeschi
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France
| | - Y Nguyen
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, Inserm, Unité Réhabilitation Chirurgicale Mini-invasive et Robotisée de l'Audition, Paris, France.,AP-HP, GHU Pitié-Salpêtrière, Service ORL, Otologie, Implants Auditifs et Chirurgie de la Base du Crâne, Paris, France
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378
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Chardey EK, Fastuca R, Beretta M, Di Blasio A, Vercellini N, Caprioglio A, Zecca PA, Macchi A. Digital Dynamic 3D Monitoring of Lower Incisors Intrusion in Lingual Orthodontics. Open Dent J 2018; 12:104-117. [PMID: 29492176 PMCID: PMC5815052 DOI: 10.2174/1874210601812010104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/20/2017] [Accepted: 01/05/2018] [Indexed: 11/22/2022] Open
Abstract
Objective The aim of the present study is to propose a 3-dimensional evaluation of lower intrusion obtained with lingual orthodontics considering not only the crowns but also dental roots. Methods 9 adult patients underwent fixed lingual orthodontic treatment with i-TTя lingual brackets system for the correction of crowding in the lower arch associated with a deep overbite. Initial records, consisting of photos, CBCTs and intraoral scans were collected. Threshold segmentation of the CBCT was performed to generate a three-dimensional virtual model of each the teeth of the lower arch, superimposed with the crown of the same teeth obtained by intraoral scan models to generate a complete set of digital composite lower arch The same procedure was performed to monitor one key step of the i-TTЯ technique consisting in lower incisors intrusion (T2). T1-T2 three-dimensional superimposition and color displacement maps were generated to measure and evaluate the movements obtained at the lower arch. Results The root displacement of the incisors during their intrusion in the early stage was totally "bone-safe" in the 88.9% (8 of 9) of the cases observed. No significant extrusion of the premolars used as anchorage unit was measured. Conclusion This method has proved to be an accurate and reliable approach to dynamically visualize the 3-dimensional positions of the teeth, including their roots, with no additional radiation for in-progress treatment monitoring. The 3-dimensional evaluation showed that the employed lingual appliance allowed to obtain significant lower incisors intrusion with negligible undesired extrusion of premolars employed as anchorage teeth.
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Affiliation(s)
- Elia Kodjo Chardey
- Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy
| | - Rosamaria Fastuca
- Department of Biomedical Sciences, Dentistry and Morphological and Functional Imaging, University of Messina, Messina, Italy
| | - Matteo Beretta
- Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy
| | - Alberto Di Blasio
- Department of Biotechnological, Biomedical and Translational Sciences, Section of Orthodontics, University of Parma, Parma, Italy
| | - Nicolò Vercellini
- Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy
| | - Alberto Caprioglio
- Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Piero Antonio Zecca
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Aldo Macchi
- Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy
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379
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Bastami F, Shahab S, Parsa A, Abbas FM, Noori Kooshki MH, Namdari M, Lisar HA, Rafiei T, Fahimipour F, Salehi M, Jafari M. Can gray values derived from CT and cone beam CT estimate new bone formation? An in vivo study. Oral Maxillofac Surg 2018; 22:13-20. [PMID: 29086089 DOI: 10.1007/s10006-017-0657-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVES The main aim of this study was to investigate whether Hounsfield unit derived from computed tomography (HU/CT) and gray value derived from cone beam computed tomography (GV/CBCT) can predict the amount of new bone formation (NBF) in the defects after bone reconstruction surgeries. MATERIALS AND METHODS Thirty calvaria defects created in 5 rabbits and grafted with both radiolucent (RL, n = 15) and radiopaque (RO, n = 15) bone substitute materials were evaluated, 8 weeks postoperatively. The defects were scanned by multislice computed tomography (Somatom®, Siemens Healthineers, Erlangen, Germany) and CBCT (NewTom VG®, Qualitative Radiology, Verona, Italy). MSCT and CBCT scans were matched to select the exact region of interest (ROI, diameter = 5 mm and height = 1 mm). HU/CT and GV/CBCT of each ROI were obtained. Mean amount of NBF in whole of the defects was measured using serial histomorphometric assessment. We investigated the correlation between HU/CT and GV/CBCT, HU/CT and NBF, and GV/CBCT and NBF generally, and separately among the RL or RO grafted defects, by linear generalized estimating equation modeling. Receiver operation characteristic analysis was performed to check the accuracy of HU/CT and GV/CBCT in diagnosing more than 10% NBF in the samples. RESULTS There were linear correlations between HU/CT and GV/CBCT, HU/CT and NBF, and GV/CBCT and NBF. CONCLUSION According to the results, both HU/CT and GV/CBCT can be considered as fairly good predictors for assessment of the amount of NBF following bone reconstruction surgeries.
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Affiliation(s)
- Farshid Bastami
- Dental Research Center, Research Institute of Dental Sciences, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahriar Shahab
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Shahed University, Tehran, Iran.
| | - Azin Parsa
- Department of Oral Radiology, Department of General and Specialized Dentistry, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.
| | - Fatemeh Mashhadi Abbas
- Department of Oral Pathology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mahshid Namdari
- Department of Biostatistics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamidreza Azimi Lisar
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahed University, Tehran, Iran
| | - Tohid Rafiei
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahed University, Tehran, Iran
| | - Farahnaz Fahimipour
- Department of Developmental Sciences, School of Dentistry, Marquette University, Milwaukee, WI, USA
| | - Majid Salehi
- Department of Tissue Engineering and Cell Therapy, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Maissa Jafari
- Department of Oral Radiology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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381
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Massimi L, Brun F, Fratini M, Bukreeva I, Cedola A. An improved ring removal procedure for in-line x-ray phase contrast tomography. Phys Med Biol 2018; 63:045007. [PMID: 29324438 DOI: 10.1088/1361-6560/aaa706] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The suppression of ring artifacts in x-ray computed tomography (CT) is a required step in practical applications; it can be addressed by introducing refined digital low pass filters within the reconstruction process. However, these filters may introduce additional ringing artifacts when simultaneously imaging pure phase objects and elements having a non-negligible absorption coefficient. Ringing originates at sharp interfaces, due to the truncation of spatial high frequencies, and severely affects qualitative and quantitative analysis of the reconstructed slices. In this work, we discuss the causes of ringing artifacts, and present a general compensation procedure to account for it. The proposed procedure has been tested with CT datasets of the mouse central nervous system acquired at different synchrotron radiation facilities. The results demonstrate that the proposed method compensates for ringing artifacts induced by low pass ring removal filters. The effectiveness of the ring suppression filters is not altered; the proposed method can thus be considered as a framework to improve the ring removal step, regardless of the specific filter adopted or the imaged sample.
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382
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Barateau A, Céleste M, Lafond C, Henry O, Couespel S, Simon A, Acosta O, de Crevoisier R, Périchon N. Calcul de dose de radiothérapie à partir de tomographies coniques : état de l’art. Cancer Radiother 2018; 22:85-100. [PMID: 29276135 DOI: 10.1016/j.canrad.2017.07.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/06/2017] [Accepted: 07/07/2017] [Indexed: 01/26/2023]
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383
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Wanner L, Ludwig U, Hövener JB, Nelson K, Flügge T. Magnetic resonance imaging-a diagnostic tool for postoperative evaluation of dental implants: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 125:e103-e107. [PMID: 29501353 DOI: 10.1016/j.oooo.2018.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/03/2018] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Compared with cone beam computed tomography (CBCT), magnetic resonance imaging (MRI) might be superior for the diagnosis of nerve lesions associated with implant placement. STUDY DESIGN A patient presented with unilateral pain associated with dysesthesia in the region of the right lower lip and chin after implant placement. Conventional orthopantomography could not identify an association between the position of the inferior alveolar nerve and the implant. For 3-dimensional display of the implant in relation to the surrounding anatomy, CBCT was compared with MRI. RESULTS MRI enabled the precise depiction of the implant position and its spatial relation to the inferior alveolar nerve, whereas the nerve position and its exact course within the mandible could not be directly displayed in CBCT. CONCLUSION MRI may be a valuable, radiation-free diagnostic tool for the visualization of intraoral hard and soft tissues, offering an objective assessment of nerve injuries by a direct visualization of the inferior alveolar neurovascular bundle.
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Affiliation(s)
- Laura Wanner
- Department of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Ute Ludwig
- Department of Radiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Jan-Bernd Hövener
- Department of Radiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Katja Nelson
- Department of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tabea Flügge
- Department of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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384
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Nascimento EHL, Gaêta-Araujo H, Andrade MFS, Freitas DQ. Prevalence of technical errors and periapical lesions in a sample of endodontically treated teeth: a CBCT analysis. Clin Oral Investig 2018; 22:2495-2503. [PMID: 29354883 DOI: 10.1007/s00784-018-2344-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/15/2018] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images. METHODS Six hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square's test and descriptive analyses were performed. RESULTS Six hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p < 0.05). Endodontic treatment quality and coronal restoration were associated with periapical status (p < 0.05). Underfilling was the most frequent technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively. CONCLUSIONS There is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals. CLINICAL RELEVANCE Evaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.
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Affiliation(s)
- Eduarda Helena Leandro Nascimento
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira, 901, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Hugo Gaêta-Araujo
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira, 901, Piracicaba, Sao Paulo, 13414-903, Brazil
| | - Maria Fernanda Silva Andrade
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira, 901, Piracicaba, Sao Paulo, 13414-903, Brazil
| | - Deborah Queiroz Freitas
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira, 901, Piracicaba, Sao Paulo, 13414-903, Brazil
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385
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Padala S, Tee BC, Beck FM, Elias K, Kim DG, Sun Z. The usefulness of cone-beam computed tomography gray values for alveolar bone linear measurements. Angle Orthod 2018; 88:227-232. [PMID: 29337632 DOI: 10.2319/060617-379.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To test a proof-of-concept that the accuracy and reliability of alveolar bone height measurements from orthodontic grade (large field-of-view [FOV], large voxel-size) cone-beam computed tomography (CBCT) images may be improved by using pixel gray values. MATERIALS AND METHODS Twenty fresh cadaver pig heads underwent CBCT scans (17 × 23 cm FOV, 0.4-mm voxel size). Buccal alveolar bone heights of maxillary first molars were measured using the conventional vision-based (VB) and the proposed gray value-assisted (GVA) methods. The GVA methods entailed localization of landmarks through observation of gray value pattern changes across tissue boundaries followed by mathematical calculation of distances between landmark pixels. Interrater reliability and accuracy of CBCT measurements made by all methods were statistically analyzed by comparing with physical measurements (gold standards). RESULTS The interrater reliability of CBCT measurements made by GVA methods was comparable to physical measurements but higher than those made by the VB method. The GVA (bend-down pattern) method yielded average measurements similar to physical measurements, while those obtained by the VB and the GVA (straight pattern) methods were significantly larger (repeated measures analysis of variance, P < .001). The GVA (bend-down pattern) method also produced significantly more measurements within one voxel size of physical measurements than did the VB and GVA (straight pattern) methods (Chi-square tests, P < .017). CONCLUSIONS These data confirm a concept that local gray value change patterns may be used to improve the accuracy and reliability of alveolar bone height measurement from large FOV and large voxel-size CBCT images.
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386
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A Simple Scatter Reduction Method in Cone-Beam Computed Tomography for Dental and Maxillofacial Applications Based on Monte Carlo Simulation. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5748281. [PMID: 29511685 PMCID: PMC5817318 DOI: 10.1155/2018/5748281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 12/04/2017] [Indexed: 12/03/2022]
Abstract
The quality of images obtained from cone-beam computed tomography (CBCT) is important in diagnosis and treatment planning for dental and maxillofacial applications. However, X-ray scattering inside a human head is one of the main factors that cause a drop in image quality, especially in the CBCT system with a wide-angle cone-beam X-ray source and a large area detector. In this study, the X-ray scattering distribution within a standard head phantom was estimated using the Monte Carlo method based on Geant4. Due to small variation of low-frequency scattering signals, the scattering signals from the head phantom can be represented as the simple predetermined scattering signals from a patient's head and subtracted the projection data for scatter reduction. The results showed higher contrast and less cupping artifacts on the reconstructed images of the head phantom and real patients. Furthermore, the same simulated scattering signals can also be applied to process with higher-resolution projection data.
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387
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Johari M, Abdollahzadeh M, Esmaeili F, Sakhamanesh V. Metal Artifact Suppression in Dental Cone Beam Computed Tomography Images Using Image Processing Techniques. JOURNAL OF MEDICAL SIGNALS AND SENSORS 2018. [PMID: 29535920 PMCID: PMC5840892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND Dental cone beam computed tomography (CBCT) images suffer from severe metal artifacts. These artifacts degrade the quality of acquired image and in some cases make it unsuitable to use. Streaking artifacts and cavities around teeth are the main reason of degradation. METHODS In this article, we have proposed a new artifact reduction algorithm which has three parallel components. The first component extracts teeth based on the modeling of image histogram with a Gaussian mixture model. Striking artifact reduction component reduces artifacts using converting image into the polar domain and applying morphological filtering. The third component fills cavities through a simple but effective morphological filtering operation. RESULTS Finally, results of these three components are combined into a fusion step to create a visually good image which is more compatible to human visual system. CONCLUSIONS Results show that the proposed algorithm reduces artifacts of dental CBCT images and produces clean images.
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Affiliation(s)
- Masoumeh Johari
- Department of Oral and Maxillofacial Radiology, Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Milad Abdollahzadeh
- Department of Communications Engineering, Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
| | - Farzad Esmaeili
- Department of Oral and Maxillofacial Radiology, Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Vahideh Sakhamanesh
- Department of Oral and Maxillofacial Radiology, Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran,Address for correspondence: Dr. Vahideh Sakhamanesh, Department of Oral and Maxillofacial Radiology, Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. E-mail:
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388
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Fakhar HB, Emami R, Moloudi K, Mosavat F. Effects of artifact removal on cone-beam computed tomography images. Dent Res J (Isfahan) 2018; 15:89-94. [PMID: 29576771 PMCID: PMC5858077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Dental implants and metal fillings may cause artifacts in cone-beam computed tomography (CBCT) images and reduce image quality and anatomic accuracy. The purposes of this study are a subjective evaluation of anatomic landmarks and linear bone measurements after applying artifact removal (low-medium) option on CBCT images. MATERIALS AND METHODS In this cross-sectional study, thirty CBCT images from thirty qualified patients were selected in a private radiology center. Low and medium artifact removal was applied to images. Three radiologists assessed the visibility of the mandibular canal, mental foramen, and lamina dura in images. Crestal width and bone length were also measured in three groups of images and was compared by exact McNemar test. ICC test (two-way random model, absolute agreement types) was calculated for comparison of linear bone measurements in three images groups. P ≤ 0.05 was considered statistically significant. RESULTS Percent agreement of determining mental foramen (outline and location), mandibular canal (outline and location), and lamina dura between three groups of images were 100%, 100%, 83.3%, 96.7%, and 56.6%, respectively. The results of exact McNemar test revealed that medium artifact removal group had a statistical difference in lamina dura observation with none and low artifact removal groups (P < 0.001). Intraclass correlation coefficient showed no statistical differences in crestal width and bone length between groups (P < 0.001). CONCLUSION Applying artifact removal does not affect the visibility of large anatomical structures and linear bone measurements, but delicate structures such as lamina dura may become less clear after artifact removal.
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Affiliation(s)
- Hooriyeh Bashizade Fakhar
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Raheleh Emami
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Semnan University of Medical Sciences, Semnan, Iran,Address for correspondence: Dr. Raheleh Emami, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Semnan University of Medical Sciences, Semnan, Iran. E-mail:
| | - Kave Moloudi
- Department of Radiology, School of Paramedical Sciences, Iran University of Medical Sciences, Semnan, Iran
| | - Farzaneh Mosavat
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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389
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Zachiu C, de Senneville BD, Tijssen RHN, Kotte ANTJ, Houweling AC, Kerkmeijer LGW, Lagendijk JJW, Moonen CTW, Ries M. Non-rigid CT/CBCT to CBCT registration for online external beam radiotherapy guidance. ACTA ACUST UNITED AC 2017; 63:015027. [DOI: 10.1088/1361-6560/aa990e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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390
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Venkatesh E, Elluru SV. Cone beam computed tomography: basics and applications in dentistry. J Istanb Univ Fac Dent 2017; 51:S102-S121. [PMID: 29354314 PMCID: PMC5750833 DOI: 10.17096/jiufd.00289] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/11/2017] [Indexed: 01/31/2023] Open
Abstract
The introduction of cone beam computed tomography (CBCT) devices, changed the way oral and maxillofacial radiology is practiced. CBCT was embraced into the dental settings very rapidly due to its compact size, low cost, low ionizing radiation exposure when compared to medical computed tomography. Alike medical CT, 3 dimensional evaluation of the maxillofacial region with minimal distortion is offered by the CBCT. This article provides an overview of basics of CBCT technology and reviews the specific application of CBCT technology to oral and maxillofacial region with few illustrations.
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Affiliation(s)
- Elluru Venkatesh
- Department of Oral, Basic and Clinical Sciences, College of Dentistry, Qassim Private Colleges, Kingdom of Saudi Arabia
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391
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Queiroz PM, Rovaris K, Gaêta-Araujo H, Marzola de Souza Bueno S, Freitas DQ, Groppo FC, Haiter-Neto F. Influence of Artifact Reduction Tools in Micro–computed Tomography Images for Endodontic Research. J Endod 2017; 43:2108-2111. [DOI: 10.1016/j.joen.2017.07.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/13/2017] [Accepted: 07/30/2017] [Indexed: 10/18/2022]
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392
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Guerra ENS, Almeida FT, Bezerra FV, Figueiredo PTDS, Silva MAG, De Luca Canto G, Pachêco-Pereira C, Leite AF. Capability of CBCT to identify patients with low bone mineral density: a systematic review. Dentomaxillofac Radiol 2017; 46:20160475. [PMID: 28555506 PMCID: PMC5965944 DOI: 10.1259/dmfr.20160475] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/12/2017] [Accepted: 05/23/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to systematically review the literature about the capability of CBCT images to identify individuals with low bone mineral density (BMD). As the literature is scarce regarding this topic, the purpose of this systematic review is also to guide future research in this area. A detailed search was performed in five databases without restrictions of time or languages. Additionally, a grey literature search was conducted. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 was applied to evaluate the methodological design of selected studies. With the inclusion of only six studies, the evidence is limited to endorse the use of CBCT assertively as a diagnostic tool for low BMD. All of the three studies that analyzed radiomorphometric indices found that the linear measurements of the mandibular inferior cortex were lower in osteoporotic individuals. CBCT-derived radiographic density vertebral and mandibular measurements were also capable for differentiating individuals with osteoporosis from individuals with normal BMD. The analysis of the cervical vertebrae showed high accuracy measurements. This systematic review indicates a scarcity of studies regarding the potential of CBCT for screening individuals with low BMD. However, the studies indicate that radiomorphometric indices and CBCT-derived radiographic density should be promising tools for differentiating individuals with osteoporosis from individuals with normal BMD.
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Affiliation(s)
| | | | | | | | - Maria A G Silva
- Faculty of Dentistry, Federal University of Goiás, Goiânia, Brazil
| | - Graziela De Luca Canto
- School of Dentistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada
- Brazilian Centre for Evidence-Based Research, Department of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Camila Pachêco-Pereira
- School of Dentistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada
| | - André F Leite
- Health Sciences Faculty, University of Brasília, Brasília, Brazil
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393
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Tomographic Evaluation of the Lower Incisor's Bone Limits in Mandibular Symphysis of Orthodontically Untreated Adults. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9103749. [PMID: 29181407 PMCID: PMC5664189 DOI: 10.1155/2017/9103749] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/14/2017] [Indexed: 11/17/2022]
Abstract
The amount of available bone in the lower incisor region is critical for periodontal preservation when planning large anteroposterior dental movements. The aims of this study were to evaluate bone limits of the lower incisors in the mandibular symphysis and to verify whether they are influenced by facial growth patterns, lower incisor inclinations, skeletal anteroposterior relationships, or patient age. Tomographic images of 40 orthodontically untreated patients were evaluated and measurements of width and height of the mandibular symphysis, thickness on the lingual and labial sides of the alveolar bone, and thickness of the entire alveolar bone were performed in sagittal view. The following cephalometric measurements were also evaluated: growth pattern (FHI), lower incisor inclination (IMPA), and skeletal anteroposterior relationships (AO-BO). Pearson's correlation test was used to assess associations among bone measurements, cephalometric measurements, and patients' ages. Weak to moderate positive correlations between FHI and bone measurements on the labial side of the incisors and total alveolar width were found. The height of the symphysis had a moderate negative correlation with FHI. It was concluded that patient age, FHI, and IMPA influenced bone limits of the lower incisors in the mandibular symphysis, while AO-BO had no influence.
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394
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Influence of patient position and other inherent factors on image quality in two different cone beam computed tomography (CBCT) devices. Eur J Radiol Open 2017; 4:132-137. [PMID: 29159206 PMCID: PMC5675893 DOI: 10.1016/j.ejro.2017.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/20/2017] [Indexed: 11/23/2022] Open
Abstract
Patient head position can affect the image quality in CBCT-examinations. CNR values can be used to evaluate image quality. Inherent factors influence effective dose variations between CBCT-devices.
Objectives The aim of this in vitro study was to evaluate how a deviation from the horizontal plane, affects the image quality in two different CBCT-devices. Methods A phantom head SK150 (RANDO, The Phantom Laboratory, Salem, NY, USA) was examined in two CBCT-units: Accuitomo 80 and Veraviewepocs 3D R100 (J. Morita Mfg. Corp. Kyoto, Japan). The phantom head was placed with the hard palate parallel to the horizontal plane and tilted 20 ° backwards. Exposures were performed with different field of views (FOVs), voxel sizes, slice thicknesses and exposure settings. Effective dose was calculated using PCXMC 2.0 (STUK, Helsinki, Finland). Image quality was assessed using contrast-to-noise-ratio (CNR). Region of interest (ROI) was set at three different levels of the mandibular bone and soft tissue, uni- and bilaterally in small and large FOVs, respectively. CNR values were calculated by CT-value and standard deviation for each ROI. Factor analysis was used to analyze the material. Results Tilting the phantom head backwards rendered significantly higher mean CNR values regardless of FOV. The effective dose was lower in small than in large FOVs and varied to a larger extent between CBCT-devices in large FOVs. Conclusions Head position can affect the image quality. Tilting the head backward improved image quality in the mandibular region. However, if influenced by other variables e.g. motion artifacts in a clinical situation, remains to be further investigated. Advances in knowledge Image quality assessed using CNR values to investigate the influence of different patient positions and FOVs.
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395
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Lim-Reinders S, Keller BM, Al-Ward S, Sahgal A, Kim A. Online Adaptive Radiation Therapy. Int J Radiat Oncol Biol Phys 2017; 99:994-1003. [DOI: 10.1016/j.ijrobp.2017.04.023] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 04/14/2017] [Indexed: 10/19/2022]
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396
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Fakhar HB, Rashtchian R, Parvin M. Effect of Dental Implant Metal Artifacts on Accuracy of Linear Measurements by Two Cone-Beam Computed Tomography Systems Before and After Crown Restoration. JOURNAL OF DENTISTRY (TEHRAN, IRAN) 2017; 14:329-336. [PMID: 29942327 PMCID: PMC6015588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES The aim of this study was to determine the impact of fixture location and crown restoration on the accuracy of linear measurements by two cone-beam computed tomography (CBCT) systems. MATERIALS AND METHODS Six dental implants were inserted in a dry human mandible in two stages. CBCT images were obtained in each stage by Alphard VEGA 3030 and Promax 3D Max systems. Imaging procedures were repeated after metallic crown placement. Two observers measured the alveolar height and width using five radiopaque markers. Values were compared to the same measurements made on initial images (prior to implant insertion) using t-test. The linear regression test was used to evaluate the effect of implant location on the accuracy of linear measurements. RESULTS The impact of fixture and fixture-crown combination on the accuracy of linear measurements of height (t = -5.2, P=0.0001 and t=-5.98, P<0.0001, respectively) and width (t=-3.42, P=0.004 and t= -2.7, P=0.015, respectively) was significantly underestimated. Metal crowns had no significant effect on measurements of bone height and width (t=-1.38, P=0.19 and t=0, P=1.00, respectively). Although both systems showed some underestimations, Promax 3D Max underestimated bone width significantly more than the other system (Alphard VEGA 3030=- 0.51mm and Promax 3D Max=-0.80). Regarding implant location, the measurements in the canine sites were found to be more accurate than the region between adjacent implants. CONCLUSIONS CBCT is an accurate and reproducible system for dental implant follow-up examinations. Metal artifacts can lead to underestimation of measurements. However, this was not statistically significant in our study.
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Affiliation(s)
- Hoorieh Bashizadeh Fakhar
- Assistant Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Roxana Rashtchian
- Postgraduate Student, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran,Corresponding author: R. Rashtchian, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran,
| | - Milad Parvin
- Postgraduate Student, Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
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397
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Nascimento EHL, Oenning ACC, Freire BB, Gaêta-Araujo H, Haiter-Neto F, Freitas DQ. Comparison of panoramic radiography and cone beam CT in the assessment of juxta-apical radiolucency. Dentomaxillofac Radiol 2017; 47:20170198. [PMID: 28871830 DOI: 10.1259/dmfr.20170198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To compare the performance of panoramic radiography (PAN) and cone beam CT (CBCT) in the detection of juxta-apical radiolucency (JAR), as well as to investigate, in CBCT images, if there are factors associated with the detection of JAR on PAN. METHODS Two oral radiologists assessed the presence of JAR in PAN and CBCT images of 175 individuals (308 mandibular third molars). The cortical plates involvement and the JAR size and location were assessed on CBCT to evaluate if these factors were related to JAR detection on PAN. McNemar's test and multiple logistic regression were performed. RESULTS PAN and CBCT differed significantly in the detection of JAR (p = 0.001). On PAN, JAR was identified on 24% of the patients while on CBCT its detection increased to 32.6%. JAR was detected only on CBCT and only on PAN in 26 and 7 cases, respectively. Distal/mesial surfaces of dental roots were where JAR was mostly located (84.5%), cortical thinning was found in 59.2% of cases and the mean (SD) of JAR size was 5.03 (±1.8) mm. However, these factors were not associated with JAR detection on PAN (p > 0.05). On the other hand, the location of the cortical involvement (if buccal or lingual) was associated with JAR detection on PAN, which was more detectable when the thinning was on buccal cortical. CONCLUSIONS Juxta-apical radiolucency is more often detected on CBCT than on PAN. JAR detection on PAN was improved when it was related to the buccal cortical plate of the mandible.
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Affiliation(s)
- Eduarda Helena Leandro Nascimento
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Anne Caroline Costa Oenning
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Bernardo Barbosa Freire
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Hugo Gaêta-Araujo
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Francisco Haiter-Neto
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Deborah Queiroz Freitas
- Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo, Brazil
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398
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Haas LF, Zimmermann GS, De Luca Canto G, Flores-Mir C, Corrêa M. Precision of cone beam CT to assess periodontal bone defects: a systematic review and meta-analysis. Dentomaxillofac Radiol 2017; 47:20170084. [PMID: 28869397 DOI: 10.1259/dmfr.20170084] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES Evaluate the diagnostic validity of CBCT in measuring periodontal bone defects when compared with the reference standard (in situ measurement). METHODS Studies in which the main objective was to evaluate the diagnostic validity of CBCT in measuring periodontal bone defects when compared with the reference standard were selected. Four databases were searched. The studies were selected by two independent reviewers. The methodology of selected studies was assessed using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies. The quality of evidence and strength of recommendation was assessed by The Grading of Recommendations Assessment Tool, Development and Evaluation. RESULTS Using a selection process in two phases, 16 studies were identified and, in seven articles meta-analysis was performed. The results from these meta-analyses showed that no difference between the measurements of CBCT and in situ for alveolar bone loss, and demonstrated a concordance of 82.82% between CBCT and in situ for the classification of the degree of furcation involvement. CONCLUSIONS Based on a moderate level of evidence, CBCT could be useful for furcation involvement periodontal cases, but it should only be used in cases where clinical evaluation and conventional radiographic imaging do not provide the information necessary for an adequate diagnosis and proper periodontal treatment planning.
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Affiliation(s)
- Letícia Fernanda Haas
- 1 Health Sciences Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | - G De Luca Canto
- 2 Department of Dentistry, Federal University of Santa Catarina, Santa Catarina, Brazil.,3 Department of Dentistry, Faculty of Medicine and Dentistry University of Alberta, Edmonton, AB, Canada
| | - Carlos Flores-Mir
- 3 Department of Dentistry, Faculty of Medicine and Dentistry University of Alberta, Edmonton, AB, Canada
| | - Márcio Corrêa
- 2 Department of Dentistry, Federal University of Santa Catarina, Santa Catarina, Brazil
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399
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Rios HF, Borgnakke WS, Benavides E. The Use of Cone-Beam Computed Tomography in Management of Patients Requiring Dental Implants: An American Academy of Periodontology Best Evidence Review. J Periodontol 2017; 88:946-959. [DOI: 10.1902/jop.2017.160548] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Hector F. Rios
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI
| | - Wenche S. Borgnakke
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI
| | - Erika Benavides
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI
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400
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Rabelo KA, Cavalcanti YW, de Oliveira Pinto MG, Sousa Melo SL, Campos PSF, de Andrade Freitas Oliveira LS, de Melo DP. Quantitative assessment of image artifacts from root filling materials on CBCT scans made using several exposure parameters. Imaging Sci Dent 2017; 47:189-197. [PMID: 28989902 PMCID: PMC5620464 DOI: 10.5624/isd.2017.47.3.189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 06/03/2017] [Accepted: 06/07/2017] [Indexed: 02/01/2023] Open
Abstract
Purpose To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos (P>.05). Conclusion Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.
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Affiliation(s)
| | | | | | | | | | | | - Daniela Pita de Melo
- Department of Oral Diagnosis, State University of Paraíba, Campina Grande, Brazil
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