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He X, Chen Z, Gao Y, Wang W, You M. Reproducibility and location-stability of radiomic features derived from cone-beam computed tomography: a phantom study. Dentomaxillofac Radiol 2023; 52:20230180. [PMID: 37664997 DOI: 10.1259/dmfr.20230180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023] Open
Abstract
OBJECTIVES This study aims to determine the reproducibility and location-stability of cone-beam computed tomography (CBCT) radiomic features. METHODS Centrifugal tubes with six concentrations of K2HPO4 solutions (50, 100, 200, 400, 600, and 800 mg ml-1) were imaged within a customized phantom. For each concentration, images were captured twice as test and retest sets. Totally, 69 radiomic features were extracted by LIFEx. The reproducibility was assessed between the test and retest sets. We used the concordance correlation coefficient (CCC) to screen qualified features and then compared the differences in the numbers of them under 24 series (four locations groups * six concentrations). The location-stability was assessed using the Kruskal-Wallis test under different concentration sets; likewise, the numbers of qualified features under six test sets were analyzed. RESULTS There were 20 and 23 qualified features in the reproducibility and location-stability experiments, respectively. In the reproducibility experiment, the performance of the peripheral groups and high-concentration sets was significantly better than the center groups and low-concentration sets. The effect of concentration on the location-stability of features was not monotonic, and the number of qualified features in the low-concentration sets was greater than that in the high-concentration sets. No features were qualified in both experiments. CONCLUSIONS The density and location of the target object can affect the number of reproducible radiomic features, and its density can also affect the number of location-stable radiomic features. The problem of feature reliability should be treated cautiously in radiomic research on CBCT.
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Affiliation(s)
- Xian He
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
| | - Zhi Chen
- School of Communication and Electronic Engineering, East China Normal University, Shanghai, China
| | - Yutao Gao
- School of Computer Science, Sichuan University, Chengdu, China
| | - Wanjing Wang
- Faculty of Mathematics, Sichuan University, Chengdu, China
| | - Meng You
- Department of Oral Medical Imaging, State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Lan Y, Huang X, Fan M, Yu H, Xie Z, Zhou Y. Accuracy evaluation of cone beam computed tomography applied to measure peri-implant bone thickness in living patients: an ex vivo and in vivo experiment. Clin Oral Investig 2022; 26:6347-6359. [PMID: 35802190 DOI: 10.1007/s00784-022-04590-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/19/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This study aims to study the accuracy of cone beam computed tomography (CBCT) for measuring peri-implant bone thickness in living patients via a novel visualization method (NVM). MATERIAL AND METHODS The validity of the NVM was verified ex vivo by measuring the same peri-implant bone thicknesses in bovine ribs by using raw postoperative CBCT (clinical measurement, CM), the visualized fused images obtained using the NVM (visualized fused measurement, VF), and hard tissue sections (gold standard measurement, GS). The NVM was applied by deconstructing the postoperative CBCT model into the Modelpost-bone and Modelimplant and replacing it with bone from preoperative CBCT and standard implant models, respectively. In vivo, 52 implants were included, and the VF of each implant was obtained using data processing methods similar to those used ex vivo. Then, we compared the results of CM and VF. RESULTS Ex vivo, the VF was similar to GS, while CM usually underestimated the peri-implant bone thickness, especially at the implant shoulder (P < 0.01). In vivo, on CBCT, areas with a peri-implant bone thickness of 0-0.50 mm were not visible, while those with a thickness of 0.50-1.00 mm were occasionally visible. There was less underestimation of bone along the implant long axis. CONCLUSIONS Thin peri-implant bones could be completely underestimated on CBCT. CBCT scans alone are insufficient to warrant surgical intervention. Our NVM facilitates the accurate visual assessment of implant dimensions. CLINICAL RELEVANCE The thickness of peri-implant bone could be completely underestimated when thinner than 1.0 mm in living patients. Familiarity with these confusing CBCT results may help clinicians and patients avoid further unnecessary evaluation, misdiagnosis, and invasive treatment.
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Affiliation(s)
- Yanhua Lan
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Xiaoyuan Huang
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Mingxing Fan
- Hangzhou 6D Dental Technologies Co., Ltd, Hangzhou, 310001, People's Republic of China
| | - Huazhen Yu
- School of Mathematical Sciences, Zhejiang University, Hangzhou, 310012, People's Republic of China
| | - Zhijian Xie
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
| | - Yiqun Zhou
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
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Tayman MA, Kamburoğlu K, Ocak M, Özen D. Effect of different voxel sizes on the accuracy of CBCT measurements of trabecular bone microstructure: A comparative micro-CT study. Imaging Sci Dent 2022; 52:171-179. [PMID: 35799972 PMCID: PMC9226237 DOI: 10.5624/isd.20220025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/24/2022] [Accepted: 04/02/2022] [Indexed: 11/18/2022] Open
Affiliation(s)
- Mahmure Ayşe Tayman
- Department of Periodontology, Faculty of Dentistry, Ankara Yıldırım Beyazıt University, Ankara, Turkey
| | - Kıvanç Kamburoğlu
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Mert Ocak
- Department of Basic Medical Sciences-Anatomy, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Doğukan Özen
- Department of Biostatistics, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey
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Kuramoto T, Takarabe S, Shiotsuki K, Shibayama Y, Hamasaki H, Akamine H, Okamura K, Chikui T, Kato T, Yoshiura K. X-ray dose reduction using additional copper filtration for dental cone beam CT. Phys Med 2020; 81:302-307. [PMID: 33349541 DOI: 10.1016/j.ejmp.2020.11.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 11/25/2022] Open
Abstract
This study aims to quantitatively evaluate the effect of additional copper-filters (Cu-filters) on the radiation dose and contrast-to-noise ratio (CNR) in a dental cone beam computed tomography (CBCT). The Cu-filter thickness and tube voltage of the CBCT unit were varied in the range of 0.00-0.20 mm and 70-90 kV, respectively. The CBCT images of a phantom with homogeneous materials of aluminum, air, and bone equivalent material (BEM) were acquired. The CNRs were calculated from the voxel values of each homogeneous material. The CTDIvol was measured using standard polymethyl methacrylate CTDI test objects. We evaluated and analyzed the effects of tube current and various radiation qualities on the CNRs and CTDIvol. We observed a tendency for higher CNR at increasing tube voltage and tube current in all the homogeneous materials. On the other hand, the CNR reduced at increasing Cu-filter thickness. The tube voltage of 90 kV showed a clear advantage in the tube current-CNR curves in all the homogeneous materials. The CTDIvol increased as the tube voltage and tube current increased and decreased with the increase in the Cu-filter thickness. When the CNR was fixed at 9.23 of BEM at an exposure setting of 90 kV/5 mA without a Cu-filter, the CTDIvol at 90 kV with Cu-filters was 8.7% lower compared with that at 90 kV without a Cu-filter. The results from this study demonstrate the potential of adding a Cu-filter for patient dose reduction while ensuring the image quality.
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Affiliation(s)
- Taku Kuramoto
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Shinya Takarabe
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Kenshi Shiotsuki
- Medical Technology Department, Oita University Hospital, 1-1 Idaigaoka, Hasama-cho, Yufu-shi, Oita 879-5593, Japan
| | - Yusuke Shibayama
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiroshi Hamasaki
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiroshi Akamine
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazutoshi Okamura
- Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Toru Chikui
- Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Toyoyuki Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazunori Yoshiura
- Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
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Evaluation of streak metal artifacts in cone beam computed tomography by using the Gumbel distribution: a phantom study. Oral Surg Oral Med Oral Pathol Oral Radiol 2020; 131:494-502. [PMID: 33020029 DOI: 10.1016/j.oooo.2020.08.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/11/2020] [Accepted: 08/15/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The aim of this study was to confirm whether streak metal artifacts (SMAs) between titanium implants on cone beam computed tomography (CBCT) images could be evaluated by using the Gumbel distribution (GD). Moreover, the influence of different scan settings on SMAs was investigated. STUDY DESIGN An iodine solution simulating dentin was placed between 2 titanium rods in an acrylic phantom. It was scanned by using CBCT at 2 settings with nearly equivalent exposure doses (90 kV, 7 mA; 78 kV, 10 mA). The images were analyzed, and the dependence of the voxel values in SMAs on GD was investigated with the coefficient of determination (r2). The location parameters, indicating the strength of the SMAs, were calculated for each scan setting and evaluated with the Mann-Whitney U test. Significance was established at p = .05. RESULTS The SMAs on CBCT images depended on GD (r2 ≥ .959). The SMAs with the 78 kV, 10 mA settings were significantly smaller than those with the 90 kV, 7 mA settings (p < .01). CONCLUSIONS SMAs on CBCT images could be evaluated by using methods based on GD. The strengths of metal artifacts varied with changes in scan settings, even at nearly equivalent exposure doses.
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Quantitative analysis of metal artifact reduction using the auto-edge counting method in cone-beam computed tomography. Sci Rep 2020; 10:8872. [PMID: 32483222 PMCID: PMC7264136 DOI: 10.1038/s41598-020-65644-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/04/2020] [Indexed: 11/10/2022] Open
Abstract
The metal artifact reduction (MAR) algorithm is used in most CBCT unit to reduce artifact from various dental materials. The performance of MAR program of a CBCT unit according to the dental material type under different imaging mode was evaluated as introducing automatic quantification of the amount of artifact reduced. Four customized phantoms with different dental prostheses (amalgam, gold, porcelain-fused-metal, zirconia) underwent CBCT scanning with and without the MAR option. The imaging was performed under varied scanning conditions; 0.2 and 0.3 mm3 voxel sizes; 70 and 100 kVp. The amount of artifacts reduced by each prosthesis and scanning mode automatically counted using canny edge detection in MATLAB, and statistical analysis was performed. The overall artifact reduction ratio was ranged from 17.3% to 55.4%. The artifact caused by the gold crown was most effectively reduced compared to the other prostheses (p < 0.05, Welch’s ANOVA analysis). MAR showed higher performance in smaller voxel size mode for all prostheses (p < 0.05, independent t-test). Automatic quantification efficiently evaluated MAR performance in CBCT image. The impact of MAR was different according to the prostheses type and imaging mode, suggesting that thoughtful consideration is required when selecting the imaging mode of CBCT.
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Razi T, Emamverdizadeh P, Nilavar N, Razi S. Comparison of the Hounsfield unit in CT scan with the gray level in cone-beam CT. J Dent Res Dent Clin Dent Prospects 2019; 13:177-182. [PMID: 31857863 PMCID: PMC6904917 DOI: 10.15171/joddd.2019.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 05/23/2019] [Indexed: 12/27/2022] Open
Abstract
Background. The present study was undertaken to compare the Hounsfield Unit (HU) in computed tomography (CT) with the gray level in CBCT in human tissues. Methods. In this study, 25 different soft and hard tissues were evaluated in 21 patients. CBCT images were taken with Newtom VGi machine (Verona, Italy) and CT images were prepared with Somatom Sensation unit (Siemens, Germany). The HU values of soft and hard tissues were compared with the gray level values of CBCT images. Results. There was a strong correlation between the HU in CT and the gray level in CBCT in soft tissues (P<0.001, R2 = 0.85) and hard tissues (P<0.001, R2 = 0.74) and in general (P<0.001, R2 = 0.91). Conclusion. A high degree of agreement was seen between HU in CT and gray level in CBCT in both hard and soft tissues. Since the gray level in CBCT was similar to HU in CT and can be used as a parameter determine bone density in implant treatment and also to determine the bone type, the CBCT technique is recommended in such cases due to its low radiation dose, short time and low cost compared to CT.
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Affiliation(s)
- Tahmineh Razi
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Parya Emamverdizadeh
- Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nadia Nilavar
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sedigheh Razi
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
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Matsuo A, Hamada H, Takahashi H, Chikazu D. Long-term structural changes and outcomes of implants in particulate cellular bone and marrow reconstructed jawbone. Clin Implant Dent Relat Res 2019; 21:360-368. [PMID: 30785240 DOI: 10.1111/cid.12723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/02/2018] [Accepted: 10/02/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Association between long-term structural changes of grafted bone and outcomes of the implants is not clear. PURPOSE Morphometrical measurements and implant success were analyzed in subjects of particulate cellular bone and marrow (PCBM) reconstruction of the jawbone. MATERIALS AND METHODS Subjects were 30 implants in 13 patients from a series of 24 PCBM reconstruction cases. The cortical bone thickness and cancellous computed tomography (CT) radiodensity values were retrospectively analyzed from the CT data of 27 subjects. The cumulative success rate of the implants in the PCBM reconstructed cases (pure graft) was compared with that of 127 implants of 56 native bone cases and 42 implants of 28 bone augmentation (partial graft) cases. RESULTS In areas of PCBM reconstruction, cancellous CT radiodensity values were significantly high immediately after the surgery, and subsequently the values became stable. Cortical thickness was significantly increased, but did not reach that of native bone. Implant success rates were statistically not different (P = 0.783) between the native bone (91.3%), the partially grafted bone (95.2%), and the PCBM reconstructed bone (93.3%). CONCLUSION Implants in pure grafted bone are mainly supported by cancellous bone, because cortical thickness remained thin for a long period of time.
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Affiliation(s)
- Akira Matsuo
- Department of Oral and Maxillofacial Surgery, Ibaraki Medical Center, Tokyo Medical University, Ibaraki, Japan
| | - Hayato Hamada
- Faculty of Medicine, Department of Oral and Maxillofacial Surgery, Tokyo Medical University, Tokyo, Japan
| | - Hidetoshi Takahashi
- Faculty of Medicine, Department of Oral and Maxillofacial Surgery, Tokyo Medical University, Tokyo, Japan
| | - Daichi Chikazu
- Faculty of Medicine, Department of Oral and Maxillofacial Surgery, Tokyo Medical University, Tokyo, Japan
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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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Magat G, Ozcan Sener S. Evaluation of trabecular pattern of mandible using fractal dimension, bone area fraction, and gray scale value: comparison of cone-beam computed tomography and panoramic radiography. Oral Radiol 2018; 35:35-42. [PMID: 30484179 DOI: 10.1007/s11282-018-0316-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/30/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVE This study was performed to compare the fractal dimension (FD), bone area fraction (BAF), and gray scale value (GSV) on digital panoramic radiography (DPR) and cross-sectional cone-beam computed tomography (CBCT) using image analysis and to determine whether a relationship exists among parameters associated with bone quality. METHODS Thirty edentulous human hemimandibles were scanned by DPR and CBCT. Ninety regions of interest (ROIs) were evaluated on DPR and CBCT images to calculate the FD and BAF. The GSV of the ROI on CBCT was also calculated. RESULTS Statistically significant differences were observed in the FD values of the ROIs between DPR and CBCT (p = 0.002) and in the BAF values of ROIs between DPR and CBCT (p = 0.017). The Spearman's correlation test revealed a statistically significant high correlation between the FD and BAF values of the ROIs on DPR and between the FD and BAF values of the ROIs on CBCT (p < 0.01). No significant correlations were observed between the GSVs of ROIs on CBCT and the FD values of ROIs on DPR, the BAF values of ROIs on DPR, the FD values of ROIs on CBCT, and the BAF values of ROIs on CBCT (p > 0.05). CONCLUSIONS The GSV did not support the FD and BAF. Additionally, DPR and CBCT did not have similar image quality for assessing the FD, BAF, and GSV. In evaluating the trabecular structure, the use of panoramic radiographs should be continued because the image resolution of CBCT is lower and its generalized dose is higher than that of panoramic radiography. These results may serve as a reference for clinical practitioners using dental CBCT to analyze the trabecular structures of alveolar bones.
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Affiliation(s)
- Guldane Magat
- Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, Necmettin Erbakan University, Karaciğan Mahallesi, No:A, Ankara Cd., No:74, 42050, Karatay/Konya, Turkey.
| | - Sevgi Ozcan Sener
- Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, Necmettin Erbakan University, Karaciğan Mahallesi, No:A, Ankara Cd., No:74, 42050, Karatay/Konya, Turkey
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11
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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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Wada M, Tsuiki Y, Suganami T, Ikebe K, Sogo M, Okuno I, Maeda Y. The relationship between the bone characters obtained by CBCT and primary stability of the implants. Int J Implant Dent 2016; 1:3. [PMID: 27747625 PMCID: PMC4981004 DOI: 10.1186/s40729-014-0003-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/20/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to investigate the correlation between the thickness of the cortical bone or the voxel values that are obtained by cone beam CT (CBCT) and the insertion torque values (ITVs) or the implant stability quotient (ISQ) values. METHODS A pig's ilium was used as the implant placement site. The implants used in this study were two kinds of diameters (3.8 mm, 5.0 mm) and two kinds of lengths (7.0 mm, 12.0 mm) having a general threadlike shape with a mechanically polished surface. To measure the bone density and the cortical thickness around the implants accurately, the CBCT scanning was performed immediately just after the formation of the implant cavity. The initial stabilities were evaluated by the ITVs and the ISQ values. The bone density and cortical thickness around the implants were measured by an implant simulation software (Landmarker ver. 5.0 with special specifications for this study). The relationships of the thickness of the cortical bone and the voxel values with the ITVs and the ISQ values were analyzed using Pearson's correlation coefficient. To evaluate the influence on the ITVs and the ISQ values among multiple factors, multiple regression analysis was performed. P < 0.05 was considered statistically significant. RESULTS A significant positive correlation was found between the thickness of the cortical bone and the ITVs or the ISQ values in all kinds of implants. In addition, a significant positive correlation was also found between the voxel values and the ITVs. From the multiple regression analysis, the thickness of the cortical bone and the voxel values had a positive influence on the ITVs and the ISQ values. In addition, the length of the implant had a positive influence on the ISQ values at the 3.8-mm-diameter implant. CONCLUSIONS In this limited study, there were correlations between the thickness of the cortical bone or the voxel values obtained from the CBCT scanning and the implant stabilities. Besides, it was confirmed that the thickness of the cortical bone, the voxel value, and the implant length had positive correlations with the ITVs and the ISQ values.
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Affiliation(s)
- Masahiro Wada
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yasutane Tsuiki
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tohru Suganami
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kazunori Ikebe
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Motofumi Sogo
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ikuhisa Okuno
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshinobu Maeda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Michetti J, Basarab A, Tran M, Diemer F, Kouame D. Cone-Beam Computed Tomography contrast validation of an artificial periodontal phantom for use in endodontics. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:7905-8. [PMID: 26738125 DOI: 10.1109/embc.2015.7320225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Validation of image processing techniques such as endodontic segmentations in cone-beam computed tomography (CBCT) is a challenging issue because of the lack of ground truth in in vivo experiments. The purpose of our study was to design an artificial surrounding tissues phantom able to provide CBCT image quality of real extracted teeth, similar to in vivo conditions. Note that these extracted teeth could be previously scanned using micro computed tomography (μCT) to access true quantitative measurements of the root canal anatomy. Different design settings are assessed in our study by comparison to in vivo images, in terms of the contrast-to-noise ratio (CNR) obtained between different anatomical structures. Concerning the root canal and the dentine, the best design setup allowed our phantom to provide a CNR difference of only 3% compared to clinical cases.
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Mai HN, Kim KR, Lee DH. Non-Radiological Method for Fabrication of a Screw-Channel Drilling Guide in Cement-Retained Implant Restorations Using Intraoral Digital Scanning and Imaging Superimposition: A Clinical Report. J Prosthodont 2016; 26:88-92. [PMID: 26965033 DOI: 10.1111/jopr.12469] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2015] [Indexed: 11/28/2022] Open
Abstract
The difficulty of retrieving the abutment screw is a major disadvantage of cement-retained implant restorations. Conventional methods for locating the screw-access hole are based largely on radiography or manual labor, which limits accuracy and clinical feasibility. This clinical report describes a non-radiological method for fabricating an accurate drilling guide for location of the screw channel using intraoral optical scanning, 3D superimposition, and computer-aided design and computer-aided manufacturing (CAD/CAM) technologies. The present technique not only improves the guide fabrication process and the accuracy of screw-channel drilling, but also has wide indications for implant restorations.
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Affiliation(s)
- Hang-Nga Mai
- Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Korea
| | - Kyung-Rok Kim
- Dental Technician, Kyungpook National University Hospital, Daegu, Korea
| | - Du-Hyeong Lee
- Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Korea
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Jiang F, Liu SSY, Xia Z, Li S, Chen J, Kula KS, Eckert G. Hounsfield unit change in root and alveolar bone during canine retraction. Am J Orthod Dentofacial Orthop 2015; 147:445-53. [PMID: 25836004 DOI: 10.1016/j.ajodo.2014.11.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 11/01/2014] [Accepted: 11/01/2014] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The objective of this study was to determine the Hounsfield unit (HU) changes in the alveolar bone and root surfaces during controlled canine retractions. METHODS Eighteen maxillary canine retraction patients were selected for this split-mouth design clinical trial. The canines in each patient were randomly assigned to receive either translation or controlled tipping treatment. Pretreatment and posttreatment cone-beam computed tomography scans of each patient were used to determine tooth movement direction and HU changes. The alveolar bone and root surface were divided into 108 divisions, respectively. The HUs in each division were measured. Mixed-model analysis of variance was applied to test the HU change distribution at the P <0.05 significance level. RESULTS The HU changes varied with the directions relative to the canine movement. The HU reductions occurred at the root surfaces. Larger reductions occurred in the divisions that were perpendicular to the moving direction. However, HUs decreased in the alveolar bone in the moving direction. The highest HU reduction was at the coronal level. CONCLUSIONS HU reduction occurs on the root surface in the direction perpendicular to tooth movement and in the alveolar bone in the direction of tooth movement when a canine is retracted.
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Affiliation(s)
- Feifei Jiang
- Postgraduate student, Department of Mechanical Engineering, Indiana University-Purdue University, Indianapolis, Ind
| | - Sean S-Y Liu
- Assistant professor, Department of Orthodontics and Oral Facial Genetics, Indiana University, Indianapolis, Ind
| | - Zeyang Xia
- Associate professor, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences and Chinese University of Hong Kong, Hong Kong, China
| | - Shuning Li
- Visiting assistant professor, Department of Mechanical Engineering, Indiana University-Purdue University, Indianapolis, Ind
| | - Jie Chen
- Professor and chair, Department of Mechanical Engineering, Indiana University-Purdue University, Indianapolis, Ind; professor, Department of Orthodontics and Oral Facial Genetics, Indiana University, Indianapolis, Ind.
| | - Katherine S Kula
- Professor and chair, Department of Orthodontics and Oral Facial Genetics, Indiana University, Indianapolis, Ind
| | - George Eckert
- Biostatistician supervisor, Department of Biostatistics, Indiana University, Indianapolis, Ind
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Nishikawa K, Kousuge Y, Sano T. Is application of a quantitative CT technique helpful for quantitative measurement of bone density using dental cone-beam CT? Oral Radiol 2015. [DOI: 10.1007/s11282-015-0202-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nishino K, Shimamoto H, Kakimoto N, Tsujimoto T, Chindasombatjaroen J, Murakami S, Furukawa S. Influence of an object's z-axis location and location on the axial plane on the voxel value representation and uniformity in cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 118:619-24. [PMID: 25442500 DOI: 10.1016/j.oooo.2014.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 07/30/2014] [Accepted: 08/06/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE This study aimed to determine the influence of an object's z-axis location and location on the axial plane on the voxel values in cone beam computed tomography. STUDY DESIGN The CTP401 and CTP486 of the Catphan 500 phantom were scanned with an Alphard-3030 at 6 locations in the z-axis. RESULTS In CTP401, the voxel values of 3 inserts showed the lowest values when the center of the radiation field corresponded to under 2 or 4 cm of the z-axis center of CTP401. In CTP486, the voxel values showed the lowest values when the center of the radiation field corresponded to under 2 or 4 cm of the z-axis center of CTP486. On the same axial plane, the voxel values at the center showed significantly lower values than the off-center locations (P = .002). CONCLUSIONS The voxel values in the Alphard-3030 changed based on the z-axis location of the radiation field and were nonuniform on the same axial plane.
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Affiliation(s)
- Kanako Nishino
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Hiroaki Shimamoto
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan.
| | - Naoya Kakimoto
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Tomomi Tsujimoto
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Jira Chindasombatjaroen
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Mahidol University, Bangkok, Thailand
| | - Shumei Murakami
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Souhei Furukawa
- Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Osaka, Japan
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Spin-Neto R, Gotfredsen E, Wenzel A. Standardized method to quantify the variation in voxel value distribution in patient-simulated CBCT data sets. Dentomaxillofac Radiol 2014; 44:20140283. [PMID: 25354021 PMCID: PMC4614169 DOI: 10.1259/dmfr.20140283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/29/2014] [Accepted: 10/28/2014] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To suggest a standardized method to assess the variation in voxel value distribution in patient-simulated CBCT data sets and the effect of time between exposures (TBE). Additionally, a measurement of reproducibility, Aarhus measurement of reproducibility (AMORe), is introduced, which could be used for quality assurance purposes. METHODS Six CBCT units were tested [Cranex(®) 3D/CRAN (Soredex Oy, Tuusula, Finland); Scanora(®) 3D/SCAN (Soredex Oy); NewTom™ 5G/NEW5 (QR srl, Verona, Italy); i-CAT/ICAT (Imaging Sciences International, Hatfield, PA); 3D Accuitomo FPD80/ACCU (Morita, Kyoto, Japan); and NewTom VG/NEWV (QR srl)]. Two sets of volumetric data of a wax-imbedded dry human skull (containing a titanium implant) were acquired by each CBCT unit at two sessions on separate days. Each session consisted 21 exposures: 1 "initial" followed by a 30-min interval (initial data set), 10 acquired with 30-min TBE (data sets 1-10) and 10 acquired with 15-min TBE (data sets 11-20). CBCT data were exported as digital imaging and communications in medicine files and converted to text files containing x, y and z positions and grey shade for each voxel. Subtractions were performed voxel-by-voxel in two set-ups: (1) between two consecutive data sets and (2) between any subsequent data set and data set 1. The mean grey shade variation for each voxel was calculated for each unit/session. RESULTS The largest mean grey shade variation was found in the subtraction set-up 2 (27-447 shades of grey, depending on the unit). Considering subtraction set-up 1, the highest variation was seen for NEW5, between data sets 1 and the initial. CONCLUSIONS Discrepancies in voxel value distribution were found by comparing the initial examination of the day with the subsequent examinations. TBE had no predictable effect on the variation of CBCT-derived voxel values. AMORe ranged between 0 and 64.
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Affiliation(s)
- R Spin-Neto
- Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark
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Razi T, Niknami M, Alavi Ghazani F. Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT. J Dent Res Dent Clin Dent Prospects 2014; 8:107-10. [PMID: 25093055 PMCID: PMC4120902 DOI: 10.5681/joddd.2014.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 02/23/2014] [Indexed: 11/17/2022] Open
Abstract
Background and aims. Cone-beam computed tomography (CBCT) is an imaging system which has many advantages over computed tomography (CT). In CT scan, Hounsfield Unit (HU) is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value). The aim of the present study was to investigate the relationship between gray scale in CBCT) and Hounsfield Unit (HU) in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.
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Affiliation(s)
- Tahmineh Razi
- Assistant Professor, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahdi Niknami
- Assistant Professor, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Fakhri Alavi Ghazani
- Post-graduate Student, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
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Bujtár P, Simonovics J, Zombori G, Fejer Z, Szucs A, Bojtos A, Batista WO, Váradi K, Sándor GK. Internal or in-scan validation: a method to assess CBCT and MSCT gray scales using a human cadaver. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 117:768-79. [DOI: 10.1016/j.oooo.2014.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/29/2014] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
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Raphael KG, Tadinada A, Bradshaw JM, Janal MN, Sirois DA, Chan KC, Lurie AG. Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study. J Oral Rehabil 2014; 41:555-63. [PMID: 24836732 DOI: 10.1111/joor.12180] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2014] [Indexed: 11/30/2022]
Abstract
Patients with temporomandibular muscle and joint disorder (TMJD) increasingly seek and receive treatment for their pain with botulinum toxin (BoNTA; botulinum toxin A). Used intramuscularly in therapeutic doses, it produces localised paresis. Such paresis creates risk of reduced bone mineral density, or 'disuse osteopenia'. Animal studies have frequently used BoNTA as a model of paralysis to induce bone changes within short periods. Osteopenic effects can be enduring in animals but have yet to be studied in humans. This is the first study in humans to examine bone-related consequences of BoNTA injections in the masticatory muscles, comparing oral and maxillofacial radiologists' ratings of trabecular bone patterns in the condyles of patients with TMJD exposed to multiple masticatory muscle injection sessions with BoNTA to a sample of patients with TMJD unexposed to masticatory muscle injections with BoNTA. Cone-beam computed tomography (CBCT)-derived images of bilateral condyles were evaluated in seven patients with TMJD receiving 2+ recent BoNTA treatment sessions for facial pain and nine demographically matched patients with TMJD not receiving BoNTA treatment. Two oral and maxillofacial radiologists evaluated CBCT images for evidence of trabecular changes consistent with osteopenia. Both evaluators noted decreased density in all participants exposed to BoNTA and in none of the unexposed participants (P < 0.001). No other abnormalities associated with reduced loading were detected. These findings need replication in a larger sample and over a longer time period, to ensure safety of patients with TMJD receiving multiple BoNTA injections for their pain.
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Affiliation(s)
- K G Raphael
- Department of Oral & Maxillofacial Pathology, Radiology, and Medicine, New York University College of Dentistry, New York, NY, USA
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Crookshank M, Ploeg HL, Ellis R, MacIntyre NJ. Repeatable calibration of Hounsfield units to mineral density and effect of scanning medium. ACTA ACUST UNITED AC 2014. [DOI: 10.12989/aba.2013.1.1.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Physical quality evaluation of voxel values in cone-beam computed tomography for dental use: three-dimensional fluctuation of voxel values in uniform materials placed inside a phantom. Oral Radiol 2014. [DOI: 10.1007/s11282-014-0169-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Spin-Neto R, Gotfredsen E, Wenzel A. Variation in voxel value distribution and effect of time between exposures in six CBCT units. Dentomaxillofac Radiol 2014; 43:20130376. [PMID: 24678846 DOI: 10.1259/dmfr.20130376] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of this study is to assess the variation in voxel value distribution in volumetric data sets obtained by six cone beam CT (CBCT) units, and the effect of time between exposures. Six CBCT units [Cranex(®) 3D (CRAN; Soredex Oy, Tuusula, Finland), Scanora(®) 3D (SCAN; Soredex Oy), NewTom™ 5G (NEWT; QR Srl, Verona, Italy), Promax(®) Dimax 3 (Planmeca Oy, Helsinki, Finland), i-CAT (Imaging Sciences International, Hatfield, PA) and 3D Accuitomo FPD80 (Morita, Kyoto, Japan)] were tested. Two volumetric data sets of a dry human skull embedded in acrylic were acquired by each CBCT unit in two sessions on separate days. Each session consisted of 20 exposures: 10 acquired with 30 min between exposures and 10 acquired immediately one after the other. CBCT data were exported as digital imaging and communications in medicine (DICOM) files and converted to text files. The text files were re-organized to contain x-, y- and z-position and grey shade for each voxel. The files were merged to contain 1 record per voxel position, including the voxel values from the 20 exposures in a session. For each voxel, subtractions were performed between Data Set 1 and the remaining 19 data sets (1 - 2, 1 - 3, etc) in a session. Means, medians, ranges and standard deviations for grey shade variation in the subtraction data sets were calculated for each unit and session. For all CBCT units, variation in voxel values was observed throughout the 20 exposures. A "fingerprint" for the grey shade variation was observed for CRAN, SCAN and NEWT. For the other units, the variation was (apparently) randomly distributed. Large discrepancies in voxel value distribution are seen in CBCT images. This variation should be considered in studies that assess minute changes in CBCT images.
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Affiliation(s)
- R Spin-Neto
- Section of Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark
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Ibrahim N, Parsa A, Hassan B, van der Stelt P, Aartman IHA, Wismeijer D. The effect of scan parameters on cone beam CT trabecular bone microstructural measurements of the human mandible. Dentomaxillofac Radiol 2013; 42:20130206. [PMID: 24132024 DOI: 10.1259/dmfr.20130206] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The objective of this study was to investigate the effect of different cone beam CT scan parameters on trabecular bone microstructure measurements. A human mandibular cadaver was scanned using a cone beam CT (3D Accuitomo 170; J.Morita, Kyota, Japan). 20 cone beam CT images were obtained using 5 different fields of view (4×4 cm, 6×6 cm, 8×8 cm, 10×10 cm and 10×5 cm), 2 types of rotation steps (180° and 360°) and 2 scanning resolutions (standard and high). Image analysis software was used to assess the trabecular bone microstructural parameters (number, thickness and spacing). All parameters were measured twice by one trained observer. Intraclass correlation coefficients showed high intraobserver repeatability (intraclass correlation coefficient, 0.95-0.97) in all parameters across all tested scan parameters. Trabecular bone microstructural measurements varied significantly, especially in smaller fields of view (p = 0.001). There was no significant difference in the trabecular parameters when using different resolutions (number, p = 0.988; thickness, p = 0.960; spacing, p = 0.831) and rotation steps (number, p = 1.000; thickness, p = 0.954; spacing, p = 0.759). The scan field of view significantly influences the trabecular bone microstructure measurements. Rotation steps (180° or 360°) and resolution (standard or high) selections are not relevant.
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Affiliation(s)
- N Ibrahim
- Department of General and Specialized Dentistry, Section of Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, Netherlands
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Azeredo F, de Menezes LM, Enciso R, Weissheimer A, de Oliveira RB. Computed gray levels in multislice and cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2013; 144:147-55. [PMID: 23810056 DOI: 10.1016/j.ajodo.2013.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 03/01/2013] [Accepted: 03/01/2013] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Gray level is the range of shades of gray in the pixels, representing the x-ray attenuation coefficient that allows for tissue density assessments in computed tomography (CT). An in-vitro study was performed to investigate the relationship between computed gray levels in 3 cone-beam CT (CBCT) scanners and 1 multislice spiral CT device using 5 software programs. METHODS Six materials (air, water, wax, acrylic, plaster, and gutta-percha) were scanned with the CBCT and CT scanners, and the computed gray levels for each material at predetermined points were measured with OsiriX Medical Imaging software (Geneva, Switzerland), OnDemand3D (CyberMed International, Seoul, Korea), E-Film (Merge Healthcare, Milwaukee, Wis), Dolphin Imaging (Dolphin Imaging & Management Solutions, Chatsworth, Calif), and InVivo Dental Software (Anatomage, San Jose, Calif). The repeatability of these measurements was calculated with intraclass correlation coefficients, and the gray levels were averaged to represent each material. Repeated analysis of variance tests were used to assess the differences in gray levels among scanners and materials. RESULTS There were no differences in mean gray levels with the different software programs. There were significant differences in gray levels between scanners for each material evaluated (P <0.001). CONCLUSIONS The software programs were reliable and had no influence on the CT and CBCT gray level measurements. However, the gray levels might have discrepancies when different CT and CBCT scanners are used. Therefore, caution is essential when interpreting or evaluating CBCT images because of the significant differences in gray levels between different CBCT scanners, and between CBCT and CT values.
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Affiliation(s)
- Fabiane Azeredo
- Department of Orthodontics, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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Ibrahim N, Parsa A, Hassan B, van der Stelt P, Wismeijer D. Diagnostic imaging of trabecular bone microstructure for oral implants: a literature review. Dentomaxillofac Radiol 2013; 42:20120075. [PMID: 23420864 DOI: 10.1259/dmfr.20120075] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Several dental implant studies have reported that radiographic evaluation of bone quality can aid in reducing implant failure. Bone quality is assessed in terms of its quantity, density, trabecular characteristics and cells. Current imaging modalities vary widely in their efficiency in assessing trabecular structures, especially in a clinical setting. Most are very costly, require an extensive scanning procedure coupled with a high radiation dose and are only partially suitable for patient use. This review examines the current literature regarding diagnostic imaging assessment of trabecular microstructure prior to oral implant placement and suggests cone beam CT as a method of choice for evaluating trabecular bone microstructure.
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Affiliation(s)
- N Ibrahim
- Department of General and Specialized Dentistry, Section of Oral Radiology, Academic Center for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, Netherlands.
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Bamba J, Araki K, Endo A, Okano T. Image quality assessment of three cone beam CT machines using the SEDENTEXCT CT phantom. Dentomaxillofac Radiol 2013; 42:20120445. [PMID: 23956235 PMCID: PMC3922264 DOI: 10.1259/dmfr.20120445] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The SEDENTEXCT Project proposed quality assurance (QA) methods and introduced a QA image quality phantom. A new prototype was recently introduced that may be improved according to previous reports. The purpose of this study is to evaluate image quality in various protocols of three cone beam CT (CBCT) machines using the proposed QA phantom. METHODS Using three CBCT machines, nine image quality parameters, including image homogeneity (noise), uniformity, geometrical distortion, pixel intensity value, contrast resolution, spatial resolution [line pair (LP) chart, point spread function (PSF) and modulation transfer function (MTF)] and metal artefacts, were evaluated using a QA phantom proposed by SEDENTEXCT. Exposure parameters, slice thickness and field of view position changed variously, and the number of total protocols was 22. RESULTS Many protocols showed a uniform gray value distribution except in the minimum slice thickness image acquired using 3D Accuitomo 80 (Morita, Kyoto, Japan) and Veraviewepocs 3Df (Morita). Noise levels differed among the protocols. There was no geometric distortion, and the pixel intensity values were correlated with the CT value. Low contrast resolution differed among the protocols, but high contrast resolution performed well in all. Many protocols showed that the maximum line pair was larger than 1 LP mm(-1) but smaller than 3 LP mm(-1). PSF and MTF did not correlate well with the pixel size. The measured metal artefact areas varied for each device. CONCLUSIONS We studied the image quality of three CBCT machines using the SEDENTEXCT phantom. Image quality varied with exposure protocols and machines.
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Affiliation(s)
- J Bamba
- Division of Radiology, Department of Oral Diagnostic Sciences, Showa University School of Dentistry, Tokyo, Japan
| | - K Araki
- Division of Radiology, Department of Oral Diagnostic Sciences, Showa University School of Dentistry, Tokyo, Japan
| | - A Endo
- Division of Radiology, Department of Oral Diagnostic Sciences, Showa University School of Dentistry, Tokyo, Japan
| | - T Okano
- Division of Radiology, Department of Oral Diagnostic Sciences, Showa University School of Dentistry, Tokyo, Japan
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Parsa A, Ibrahim N, Hassan B, Motroni A, van der Stelt P, Wismeijer D. Influence of cone beam CT scanning parameters on grey value measurements at an implant site. Dentomaxillofac Radiol 2012; 42:79884780. [PMID: 22933535 DOI: 10.1259/dmfr/79884780] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system. METHODS A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170(®), Morita, Japan) and (NewTom 5G(®), QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys(®) software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio(®) 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed. RESULTS Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively). CONCLUSIONS Grey-level values from CBCT images are influenced by device and scanning settings.
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Affiliation(s)
- A Parsa
- Department of General and Specialized Dentistry, Section Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands.
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