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Ketelhut S, Kuhlmann ML, Büermann L, Pirl L, Borowski M. Simulation study on the conversion between CT and CBCT dose quantities via the effective dose. Biomed Phys Eng Express 2023; 9:065030. [PMID: 37875106 DOI: 10.1088/2057-1976/ad065e] [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] [Received: 05/30/2023] [Accepted: 10/24/2023] [Indexed: 10/26/2023]
Abstract
In recent years, cone-beam computed tomography (CBCT) has been used in many imaging tasks traditionally performed by computed tomography (CT). This has created challenges for dosimetry, as the dose quantities in CBCT and CT, i.e. the dose-area product (DAP) and dose-length product (DLP), are not mutually convertible. Convertibility would be desirable to compare doses in similar clinical studies performed using CT or CBCT and ultimately for the application of diagnostic reference levels (DRLs). In this work, the conversion of the DAP into the DLP and vice versa via the effective doseEis investigated with the aim of finding common diagnostic reference levels. The dose calculation was performed using Monte Carlo simulations for scan regions with imaging tasks, which can be carried out either with CT or CBCT scanners. Four regions in the head and four in the trunk were chosen. The calculations resulted in conversion coefficientsk=DAPDLPof 30(4) cm for the cranium, 22(4) cm for the facial bones, 24(2) cm for the paranasal sinuses, 18(2) cm for the cervical spine, 78(12) cm for the thorax, 85(13) cm for the upper abdomen, 57(6) cm for the lumbar spine and 70(12) cm for the pelvis.
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Affiliation(s)
- Steffen Ketelhut
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - Marie-Luise Kuhlmann
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - Ludwig Büermann
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - Lukas Pirl
- Städtisches Klinikum Braunschweig gGmbH, Freisestraße 9/10, 38118 Braunschweig, Germany
| | - Markus Borowski
- Städtisches Klinikum Braunschweig gGmbH, Freisestraße 9/10, 38118 Braunschweig, Germany
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Benavides E, Bhula A, Gohel A, Lurie AG, Mallya SM, Ramesh A, Tyndall DA. Patient shielding during dentomaxillofacial radiography: Recommendations from the American Academy of Oral and Maxillofacial Radiology. J Am Dent Assoc 2023; 154:826-835.e2. [PMID: 37530694 DOI: 10.1016/j.adaj.2023.06.015] [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] [Received: 05/12/2023] [Accepted: 06/13/2023] [Indexed: 08/03/2023]
Abstract
BACKGROUND The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging. TYPES OF STUDIES REVIEWED The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging. RESULTS Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging. PRACTICAL IMPLICATIONS This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.
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Orhan K, Pauwels R, Chen Y, Song D, Jacobs R. Estimation of the radiation dose for dental spectral cone-beam CT. Dentomaxillofac Radiol 2021; 50:20200372. [PMID: 33353401 DOI: 10.1259/dmfr.20200372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The purpose of this study was to estimate the radiation dose for a dental spectral cone-beam CT (SCBCT) unit at different scanning parameters. METHODS Radiation dose measurements were performed for a commercially available dental SCBCT. Scans were obtained at different exposure times and fields of view (FOV), both for non-spectral (25×18 cm, 14×18 cm, 14×12 cm, 9×9 cm, 6×6 cm) and spectral modes (14×18 cm, 14×12 cm, 9×9 cm, 6×6 cm) with the tube voltage alternating between 80 and 110 kV for spectral mode, and fixed at 110 kV for non-spectral mode. An ion chamber was used for air kerma and dose area product (DAP) measurements. The effective dose was estimated based on the mAs using previously published logarithmic curves for CBCT units with a similar X-ray spectrum. RESULTS The adult effective dose, in non-spectral mode, was 44-269 µSv for small FOVs, 131-336 µSv for the medium FOV, and 163-476 µSv for the large FOV. In spectral mode, the estimated adult effective doses were 96-206 µSv for small, 299 µSv for medium and 372 µSv for large FOV protocols. Paediatric effective doses were estimated to be 75% higher than corresponding adult doses. CONCLUSION SCBCT showed comparable doses with other CBCT devices, but DAP values were generally above currently published DRLs. Spectral imaging might allow for artefact reduction at comparable dose levels, which should be assessed in further image quality studies at both a technical and diagnostic levels.
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Affiliation(s)
- Kaan Orhan
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dento Maxillofacial Radiology, Ankara University, Faculty of Dentistry, Ankara, Turkey
| | - Ruben Pauwels
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.,Department of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Yi Chen
- UEG Medical Imaging Equipment Co. Ltd, Shanghai, China
| | - Dandan Song
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging & Pathology, Faculty of Medicine, University of Leuven and Oral & Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium.,Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden
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Li Y, Huang B, Cao J, Fang T, Liu G, Li X, Wu J. ESTIMATING RADIATION DOSE TO MAJOR ORGANS IN DENTAL X-RAY EXAMINATIONS: A PHANTOM STUDY. RADIATION PROTECTION DOSIMETRY 2020; 192:328-334. [PMID: 33320946 DOI: 10.1093/rpd/ncaa196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/30/2020] [Accepted: 11/05/2020] [Indexed: 06/12/2023]
Abstract
The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23-1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.
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Affiliation(s)
- Yong Li
- Department of Nuclear Science and Technology, School of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Bingsheng Huang
- Medical AI Lab, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518071, China
| | - Jun Cao
- Department of Stomatology, Shenzhen University General Hospital, Shenzhen 518055, China
| | - Tianqi Fang
- Medical AI Lab, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518071, China
- Shenzhen University General Hospital Clinical Research Center for Neurological Diseases, Shenzhen 518071, China
| | - Guoqing Liu
- Department of Nuclear Science and Technology, School of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xuguang Li
- Department of Stomatology, Shenzhen University General Hospital, Shenzhen 518055, China
| | - Jiabao Wu
- Department of Nuclear Science and Technology, School of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
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Mah E, Ritenour ER, Yao H. A review of dental cone-beam CT dose conversion coefficients. Dentomaxillofac Radiol 2020; 50:20200225. [PMID: 33112658 DOI: 10.1259/dmfr.20200225] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The purpose of this study was to review the literature to examine the usage and magnitude of effective dose conversion factors (DCE) for dental cone beam CT (CBCT) scanners. METHODS A PubMed literature search for publications relating to radiation dosimetry in dental radiography was performed. Papers were included if they reported DCE, or reported ICRP 103 effective dose and dose-area product. 71 papers relating to dental CBCT dosimetry were found, of which eight reported effective dose conversion factors or provided enough information to calculate dose conversion factors. Scanner model, effective dose, dose-area product, tube voltage, field of view size and DCE were extracted from the papers for analysis. RESULTS DCE values ranged from 0.035 to 0.31 µSv/mGy-cm2 with a mean of 0.129 µSv/mGy-cm2 (SD = 0.056). When categorized into small (<100 cm2), medium (100-225 cm2) and large (>225 cm2) fields of view (FOV), linear fits to the effective dose and dose-area product yielded slopes of 0.129, 0.111 and 0.074 µSv/mGy-cm2 for small, medium and large FOVs respectively. CONCLUSION The range of reported DCE values and spread with respect to field of view category suggests that DCE values that depend on FOV would provide more accurate effective dose estimates. Tube voltage was found to be a smaller factor in determining DCE. Reasonable values for DCE taking into account FOV size were obtained. There is considerable room for more work to be done to examine the behaviour of DCE with changes to patient age and dental CBCT imaging parameters.
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Affiliation(s)
- Eugene Mah
- Department of Radiology & Radiologic Imaging, Medical University of South Carolina, Charleston, SC, USA.,Department of Bioengineering, Clemson University, Clemson-MUSC Bioengineering Program, Charleston, SC, USA
| | - E Russell Ritenour
- Department of Radiology & Radiologic Imaging, Medical University of South Carolina, Charleston, SC, USA.,Department of Bioengineering, Clemson University, Clemson-MUSC Bioengineering Program, Charleston, SC, USA
| | - Hai Yao
- Department of Bioengineering, Clemson University, Clemson-MUSC Bioengineering Program, Charleston, SC, USA
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Kurt MH, Bağış N, Evli C, Atakan C, Orhan K. Comparison of the different voxel sizes in the estimation of peri-implant fenestration defects using cone beam computed tomography: an ex vivo study. Int J Implant Dent 2020; 6:58. [PMID: 33006000 PMCID: PMC7530157 DOI: 10.1186/s40729-020-00254-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/27/2020] [Indexed: 11/10/2022] Open
Abstract
Background To examine the influence of voxel sizes to detect of peri-implant fenestration defects on cone beam computed tomography (CBCT) images. Materials and methods This study performed with three sheep heads both maxilla and mandible and two types of dental implant type 1 zirconium implant (Zr40) (n = 6) and type 2 titanium implant (Ti22) (n = 10). A total of 14 peri-implant fenestrations (8 buccal surfaces, 6 palatal/lingual surface) were created while 18 surfaces (8 buccal, 10 palatal/lingual) were free of fenestrations. Three observers have evaluated the images of fenestration at each site. Images obtained with 0.75 mm3, 0.100 mm3, 0.150 mm3, 0.200 mm3, and 0.400 mm3 voxel sizes. For intra- and inter-observer agreements for each voxel size, Kappa coefficients were calculated. Results Intra- and inter-observer kappa values were the highest for 0.150 mm3, and the lowest in 0.75 mm3 and 0.400 mm3 voxel sizes for all types of implants. The highest area under the curve (AUC) values were found higher for the scan mode of 0.150 mm3, whereas lower AUC values were found for the voxel size for 0.400 mm3. Titanium implants had higher AUC values than zirconium with the statistical significance for all voxel sizes (p ≤ 0.05). Conclusion A voxel size of 0.150 mm3 can be used to detect peri-implant fenestration bone defects. CBCT is the most reliable diagnostic tool for peri-implant fenestration bone defects.
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Affiliation(s)
- Mehmet Hakan Kurt
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey.
| | - Nilsun Bağış
- Dentistry Department of Periodontology, Ankara University, Ankara, Turkey
| | - Cengiz Evli
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey
| | - Cemal Atakan
- Faculty of Science Department of Statistics, Ankara University, Ankara, Turkey
| | - Kaan Orhan
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey.,Medical Design Application and Research Center (MEDITAM), Ankara University, Ankara, Turkey
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Lee C, Yoon J, Han SS, Na JY, Lee JH, Kim YH, Hwang JJ. Dose assessment in dental cone-beam computed tomography: Comparison of optically stimulated luminescence dosimetry with Monte Carlo method. PLoS One 2020; 15:e0219103. [PMID: 32231373 PMCID: PMC7108699 DOI: 10.1371/journal.pone.0219103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 03/04/2020] [Indexed: 12/02/2022] Open
Abstract
The variety of cone-beam computed tomography (CBCT) machines and their applications has rapidly increased in recent years, making the dose evaluation of individual devices an important issue. Patient doses from CBCT were assessed with two different methods: optically stimulated luminescence dosimeter (OSLD) measurements and Monte Carlo (MC) simulations, in four different examination modes. Based on an analysis of the measurement process and the obtained values, a recommendation is made regarding which method is more practical and efficient for acquiring the effective dose of CBCT. Twenty-two OSLDs were calibrated and equipped in human phantoms of head and neck organs. They were exposed to radiation from two CBCT units—CS9300 (Carestream Dental LLC, Atlanta, Georgia) and RAYSCAN α+ (Ray Co. Ltd, Hwaseong-si, Korea)—using two different examination modes. The dose recorded using the OSLDs was used to calculate the organ dose and the effective dose for each unit in each examination mode. These values were also calculated using MC software, PCXMC (STUK, Helsinki, Finland). The organ doses and effective doses obtained using both methods were compared for each examination mode of the individual units. The OSLD-measured effective dose value was higher than that obtained using the MC method for each examination mode, except the dual jaw mode of CS9300. The percent difference of the effective dose between the two methods ranged from 4.0% to 14.3%. The dose difference between the methods decreased as the field of view became smaller. The organ dose values varied according to the method, although the overall trend was similar for both methods. The organs showing high doses were mostly consistent for both methods. In this study, the effective dose obtained by OSLD measurements and MC simulations were compared, and both methods were described in detail. As a relatively efficient and easy-to-perform method, we cautiously suggest using MC simulations for dose evaluations in the future.
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Affiliation(s)
- Chena Lee
- Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jeongmin Yoon
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Radiation Oncology, Sheikh Khalifa Specialty Hospital, Ras Al Khaimah, United Arab Emirates
| | - Sang-Sun Han
- Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul, Republic of Korea
- * E-mail:
| | - Ji Yeon Na
- Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jeong-Hee Lee
- Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Young Hyun Kim
- Department of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jae Joon Hwang
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan, Korea
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Kottou S, Zapros A, Stefanopoulou N, Krompas N, Tsapaki V. CONE BEAM CT IN DENTAL IMPLANT PLANNING: HOW CLOSE ARE PATIENT DOSIMETRY RESULTS WITH DATA FROM PHANTOM STUDIES FOUND IN LITERATURE? RADIATION PROTECTION DOSIMETRY 2019; 187:321-326. [PMID: 31297525 DOI: 10.1093/rpd/ncz169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/29/2019] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
Advantages of Cone Beam Computed Tomography (CBCT) include high-quality 3D imaging and reduced radiation exposure with relatively low cost. In this study, patient radiation exposure in CBCT implant planning dentistry was measured in terms of Kerma Area Product (KAP). Data were obtained from 217 CBCT scans on 168 individuals using a CS9300 Carestream system. Scans were made using 80-90 kVp, 4-5 mA, 8 and 13.3 s exposure time (depending on voxel size) and a fixed field of view (FOV) of 10 × 10 cm2 (medium). Mean KAP was estimated using two voxel sizes 180 × 180 × 180 μm3 and 200 × 200 × 200 μm3 and found to be 399 and 314 mGycm2, respectively. Corresponding KAP values found in literature ranged between 210 and 2140 mGycm2. Mean E was estimated using conversion coefficient factors found in literature, according to FOV size and tube voltage value and found to range between 24 and 161 μSv.
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Affiliation(s)
- S Kottou
- National and Kapodistrian University of Athens, School of Medicine, Medical Physics Lab, Athens, Greece
| | - A Zapros
- Konstantopoulio General Hospital, Athens, Greece
| | | | - N Krompas
- Branemark Osseointegration Center, Athens, Greece
| | - V Tsapaki
- Konstantopoulio General Hospital, Athens, Greece
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Qiang W, Qiang F, Lin L. ESTIMATION OF EFFECTIVE DOSE OF DENTAL X-RAY DEVICES. RADIATION PROTECTION DOSIMETRY 2019; 183:417-421. [PMID: 30169836 DOI: 10.1093/rpd/ncy159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/07/2018] [Accepted: 08/21/2018] [Indexed: 06/08/2023]
Abstract
This study aims to estimate the effective doses of dental X-ray devices under common scanning protocols. After putting TLDs in the Alderson Radiation Therapy Phantom, we exposed the phantom under common scanning protocols of three dental X-ray devices, namely CBCT, dental panoramic machine and intraoral round cone device. Then effective doses were calculated using the measured absorbed doses of organs and tissues. Tissue weighting factors recommended by the ICRP were adopted in the calculation. Effective doses under common scanning protocols of three Dental X-ray devices were obtained. The effective dose of dental CT was 0.20 mSv, and that of dental panoramic machine and intraoral radiography were 0.013 and 0.0050 mSv, respectively. The tissue absorbed doses of dental CT scan were 0.63 mGy of brain, 7.7 mGy of salivary glands, 8.7 mGy of thyroid and 4.0 mGy of the lens of the eye. The tissue absorbed doses from dental panoramic machine are 0.62 mGy of salivary glands and 0.25 mGy of thyroid. And finally the tissue absorbed dose of intraoral radiography was 0.80 mGy of salivary gland. Among the three dental X-ray devices studied, dental CBCT scan can cause much higher effective dose than the other two. Brain, salivary glands, thyroid and the lens of the eye are tissues receiving relatively higher absorbed doses.
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Affiliation(s)
- Wang Qiang
- Changzhou CDC, No. 203, Taishan Road, Changzhou, Jiangsu, China
| | - Fu Qiang
- Changzhou CDC, No. 203, Taishan Road, Changzhou, Jiangsu, China
| | - Lin Lin
- Changzhou CDC, No. 203, Taishan Road, Changzhou, Jiangsu, China
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Kralik I, Faj D, Lauc T, Škarica M, Popić J, Brkic H. Dose area product in estimation of effective dose of the patients undergoing dental cone beam computed tomography examinations. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2018; 38:1412-1427. [PMID: 30264736 DOI: 10.1088/1361-6498/aae4e8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE To investigate the relationship of the effective dose and dose area product (DAP) in dental cone beam computed tomography (CBCT) examinations and to propose conversion factors for estimation of effective doses of the patients using DAP. Dependence of organ doses on DAP was also investigated. MATERIALS AND METHODS Different exposure geometries in Cranex3Dx CBCT device were simulated using Monte Carlo simulation and computational anthropomorphic phantom. Then organ doses and effective dose for every exposure geometry was compared to DAP and analysed. RESULTS The effective dose in all simulated CBCT protocols and positions with 180° tube rotation ranged from 5 μSv for 50 × 50 mm2 field of view (FOV) localised on one tooth using lowest resolution to 265 μSv for the largest FOV and highest resolution. In case of 360° tube rotation the effective dose ranges from 6 to 332 μSv for the same FOV sizes and positions as well as resolutions as in 180° tube rotation. CONCLUSIONS Though the DAP introduces a large uncertainty in the risk measure in dental CBCT, it represents the dose and FOV size which are the most important scanning parameters affecting the dose. To decrease uncertainty in the risk measure, the effective dose has to be estimated for usual clinical positions of the FOV.
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11
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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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Kim EK, Han WJ, Choi JW, Battulga B. Estimation of the effective dose of dental cone-beam computed tomography using personal computer-based Monte Carlo software. Imaging Sci Dent 2018; 48:21-30. [PMID: 29581946 PMCID: PMC5863016 DOI: 10.5624/isd.2018.48.1.21] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/22/2017] [Accepted: 12/28/2017] [Indexed: 11/30/2022] Open
Abstract
Purpose To calculate the effective doses of cone-beam computed tomography (CBCT) using personal computer-based Monte Carlo (PCXMC) software (Radiation and Nuclear Safety Authority, Helsinki, Finland) and to compare the calculated effective doses with those measured using thermoluminescent dosimeters (TLDs) and an anthropomorphic phantom. Materials and Methods An Alphard VEGA CBCT scanner (Asahi Roentgen Ind. Co., Kyoto, Japan) with multiple fields of view (FOVs) was used for this study. The effective doses of the scout and main projections of CBCT using 1 large and 2 medium FOVs with a height >10 cm were calculated using PCXMC and PCXMCRotation software and then were compared with the doses obtained using TLD-100 LiF and an anthropomorphic adult human male phantom. Furthermore, it was described how to determine the reference points on the Y- and Z-axes in PCXMC, the important dose-determining factors in this software. Results The effective doses at CBCT for 1 large (20.0 cm×17.9 cm) and 2 medium FOVs (15.4 cm×15.4 cm and 10.2 cm×10.2 cm) calculated by the PCXMC software were 181, 300, and 158 µSv, respectively. These values were comparable (16%–18% smaller) to those obtained through TLD measurements in each mode. Conclusion The use of PCXMC software could be an alternative to the TLD measurement method for effective dose estimation in CBCT with large and medium FOVs.
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Affiliation(s)
- Eun-Kyung Kim
- Department of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Cheonan, Korea
| | - Won-Jeong Han
- Department of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Cheonan, Korea
| | - Jin-Woo Choi
- Department of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Cheonan, Korea
| | - Bulgan Battulga
- Dental Hospital, School of Dentistry, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
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13
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Tsapaki V. Radiation protection in dental radiology – Recent advances and future directions. Phys Med 2017; 44:222-226. [DOI: 10.1016/j.ejmp.2017.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/21/2017] [Accepted: 07/22/2017] [Indexed: 10/19/2022] Open
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14
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Conte G, Scola E, Calloni S, Brambilla R, Campoleoni M, Lombardi L, Di Berardino F, Zanetti D, Gaini LM, Triulzi F, Sina C. Flat Panel Angiography in the Cross-Sectional Imaging of the Temporal Bone: Assessment of Image Quality and Radiation Dose Compared with a 64-Section Multisection CT Scanner. AJNR Am J Neuroradiol 2017; 38:1998-2002. [PMID: 28751512 DOI: 10.3174/ajnr.a5302] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/22/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Cross-sectional imaging of the temporal bone is challenging because of the complexity and small dimensions of the anatomic structures. We evaluated the role of flat panel angiography in the cross-sectional imaging of the temporal bone by comparing its image quality and radiation dose with a 64-section multisection CT scanner. MATERIALS AND METHODS We retrospectively collected 29 multisection CT and 29 flat panel angiography images of normal whole-head temporal bones. Image quality was assessed by 2 neuroradiologists, who rated the visualization of 30 anatomic structures with a 3-point ordinal scale. The radiation dose was assessed with an anthropomorphic phantom. RESULTS Flat panel angiography showed better image quality than multisection CT in depicting the anterior and posterior crura of the stapes, the footplate of the stapes, the stapedius muscle, and the anterior ligament of the malleus (P < .05). In contrast, multisection CT showed better image quality than flat panel angiography in assessing the tympanic membrane, the bone marrow of the malleus and incus, the tendon of the tensor tympani, the interscalar septum, and the modiolus of the cochlea (P < .05). Flat panel angiography had a significantly higher overall image quality rating than multisection CT (P = .035). A reduction of the effective dose of approximately 40% was demonstrated for flat panel angiography compared with multisection CT. CONCLUSIONS Flat panel angiography shows strengths and weaknesses compared with multisection CT. It is more susceptible to artifacts, but due to the higher spatial resolution, it shows equal or higher image quality in assessing some bony structures of diagnostic interest. The lower radiation dose is an additional advantage of flat panel angiography.
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Affiliation(s)
- G Conte
- From the Postgraduation School of Radiodiagnostics (G.C., S.C.)
| | - E Scola
- Neuroradiology Unit (E.S., L.L., F.T., C.S.)
| | - S Calloni
- From the Postgraduation School of Radiodiagnostics (G.C., S.C.)
| | - R Brambilla
- Health Physics Unit (R.B., M.C.), Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Ca'Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - M Campoleoni
- Health Physics Unit (R.B., M.C.), Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Ca'Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - L Lombardi
- Neuroradiology Unit (E.S., L.L., F.T., C.S.)
| | | | | | - L M Gaini
- Otolaryngology Unit (L.M.G.), Department of Clinical Sciences and Community Health, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Ca'Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - F Triulzi
- Department of Pathophysiology and Transplantation (F.T.), Università degli Studi di Milano, Milan, Italy.,Neuroradiology Unit (E.S., L.L., F.T., C.S.)
| | - C Sina
- Neuroradiology Unit (E.S., L.L., F.T., C.S.)
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15
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Goulston R, Davies J, Horner K, Murphy F. Dose optimization by altering the operating potential and tube current exposure time product in dental cone beam CT: a systematic review. Dentomaxillofac Radiol 2016; 45:20150254. [PMID: 26732433 DOI: 10.1259/dmfr.20150254] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Current guidelines highlight the need to optimize exposure parameters on CBCT equipment to levels that are as low as diagnostically acceptable. This systematic review aimed to answer the question "Can altering operating potential (kV) and tube current exposure time product (mAs) on CBCT machines reduce radiation dose to patients undergoing dental and/or maxillofacial scans without a detrimental impact on image quality/diagnostic accuracy?" METHODS Studies were selected and results reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. For each individual study, two authors (RG and JD or KH) independently extracted data using a specifically designed collection form, and an overall quality value was assigned using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Any disagreements in the overall quality value of a study were resolved by discussion between the current authors. RESULTS Nearly 75% of studies were considered to be of low or very low methodological quality using the GRADE system, and more studies stated that their results applied only in the specific situations they had investigated. However, most studies demonstrated that patient dose reduction is possible without a clinically relevant reduction in image quality. CONCLUSIONS For many CBCT machines, it should be possible to optimize one, or more, of the investigated exposure parameters and therefore reduce patient radiation dose, while maintaining diagnostic image quality for some diagnostic tasks. However, more rigorous research is still required.
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Affiliation(s)
- Rebekah Goulston
- 1 Dental Radiology Department, University Dental Hospital of Manchester, Manchester, UK
| | - Jonathan Davies
- 2 University of Manchester, School of Dentistry, Manchester, UK
| | - Keith Horner
- 2 University of Manchester, School of Dentistry, Manchester, UK
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16
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Ludlow JB, Timothy R, Walker C, Hunter R, Benavides E, Samuelson DB, Scheske MJ. Effective dose of dental CBCT-a meta analysis of published data and additional data for nine CBCT units. Dentomaxillofac Radiol 2015; 44:20140197. [PMID: 25224586 DOI: 10.1259/dmfr.20140197] [Citation(s) in RCA: 273] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES This article analyses dose measurement and effective dose estimation of dental CBCT examinations. Challenges to accurate calculation of dose are discussed and the use of dose-height product (DHP) as an alternative to dose-area product (DAP) is explored. METHODS The English literature on effective dose was reviewed. Data from these studies together with additional data for nine CBCT units were analysed. Descriptive statistics, ANOVA and paired analysis are used to characterize the data. RESULTS PubMed and EMBASE searches yielded 519 and 743 publications, respectively, which were reduced to 20 following review. Reported adult effective doses for any protocol ranged from 46 to 1073 µSv for large fields of view (FOVs), 9-560 µSv for medium FOVs and 5-652 µSv for small FOVs. Child effective doses from any protocol ranged from 13 to 769 µSv for large or medium FOVs and 7-521 µSv for small FOVs. Effective doses from standard or default exposure protocols were available for 167 adult and 52 child exposures. Mean adult effective doses grouped by FOV size were 212 µSv (large), 177 µSv (medium) and 84 µSv (small). Mean child doses were 175 µSv (combined large and medium) and 103 µSv (small). Large differences were seen between different CBCT units. Additional low-dose and high-definition protocols available for many units extend the range of doses. DHP was found to reduce average absolute error for calculation of dose by 45% in comparison with DAP. CONCLUSIONS Large exposure ranges make CBCT doses difficult to generalize. Use of DHP as a metric for estimating effective dose warrants further investigation.
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Affiliation(s)
- J B Ludlow
- 1 North Carolina Oral Health Institute, Koury Oral Health Sciences, Chapel Hill, NC, USA
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17
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Al-Okshi A, Lindh C, Salé H, Gunnarsson M, Rohlin M. Effective dose of cone beam CT (CBCT) of the facial skeleton: a systematic review. Br J Radiol 2015; 88:20140658. [PMID: 25486387 DOI: 10.1259/bjr.20140658] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE To estimate effective dose of cone beam CT (CBCT) of the facial skeleton with focus on measurement methods and scanning protocols. METHODS A systematic review, which adhered to the preferred reporting items for systematic reviews (PRISMA) Statement, of the literature up to April 2014 was conducted. Data sources included MEDLINE®, The Cochrane Library and Web of Science. A model was developed to underpin data extraction from 38 included studies. RESULTS Technical specifications of the CBCT units were insufficiently described. Heterogeneity in measurement methods and scanning protocols between studies made comparisons of effective doses of different CBCT units and scanning protocols difficult. Few studies related doses to image quality. Reported effective dose varied across studies, ranging between 9.7 and 197.0 μSv for field of views (FOVs) with height ≤5 cm, between 3.9 and 674.0 μSv for FOVs of heights 5.1-10.0 cm and between 8.8 and 1073.0 μSv for FOVs >10 cm. There was an inconsistency regarding reported effective dose of studies of the same CBCT unit with the same FOV dimensions. CONCLUSION The review reveals a need for studies on radiation dosages related to image quality. Reporting quality of future studies has to be improved to facilitate comparison of effective doses obtained from examinations with different CBCT units and scanning protocols. A model with minimum data set on important parameters based on this observation is proposed. ADVANCES IN KNOWLEDGE Data important when estimating effective dose were insufficiently reported in most studies. A model with minimum data based on this observation is proposed. Few studies related effective dose to image quality.
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Affiliation(s)
- A Al-Okshi
- 1 Department of Oral and Maxillofacial Radiology, Faculty of Odontology, Malmö University, Malmö, Sweden
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