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Benmessaoud M, Dadouch A, Maghnouj A, Lemmassi A, Tahiri M, El-Ouardi Y, Ait Ouaggou I. Establishment of local diagnostic reference levels for paediatric abdominal-pelvis and Chest-abdominal-pelvis computed tomography in Morocco: suggests the need for improved optimization efforts. RADIATION PROTECTION DOSIMETRY 2023:7160592. [PMID: 37177805 DOI: 10.1093/rpd/ncad149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/25/2023] [Accepted: 04/05/2023] [Indexed: 05/15/2023]
Abstract
The purpose of the current study was to derive the local diagnostic reference levels (LDRLs) for paediatric abdominal-pelvis (AP) and chest-abdominal-pelvis (CAP) computed tomography in Morocco. The data were gathered retrospectively from two hospitals for 6 months. The LDRLs were defined by volume CT dose index (CTDIvol), dose-length product (DLP) per sequence, DLP per procedure and size-specific dose estimates (SSDE). The SSDE assessment was based on the effective diameters of patients scanned. A total of 630 CT examinations were collected involving 324 AP and 306 CAP scans. The proposed LDRLs for AP, in terms of CTDIvol (mGy), were 6.9, 8.5, 8.5 and 8.5 for < 1, 1 to < 5, 5 to < 10 and 10 to < 15 y age groups, respectively. In terms of DLP (mGy.cm) per procedure, they were 436.3, 534.5, 687.9 and 961.7. In terms of SSDE (mGy), thet were 16.73, 16.83, 17.5 and 15.8 for < 1, 1 to < 5, 5 to < 10 and 10 to < 15 y, respectively. The corresponding LDRLs for CAP, in terms of CTDIvol (mGy), were 7.3, 7.3, 7.3 and 10.35. In terms of DLP (mGy.cm) per procedure, they were 531, 622.5, 705 and 936. In terms of SSDE (mGy), they were 16.22, 15.05, 14.47 and 15.2, respectively, for the four age groups. The derived dose levels were mostly higher than those found in other studies, which demonstrates the need for dose optimization and paediatric protocol standardization as well as the timeliness of the intent to establish not only local DRLs but national ones in the near future.
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Affiliation(s)
- Mounir Benmessaoud
- Sidi Mohamed Ben Abdellah University, Faculty of Sciences Dhar EL Mahraz, Fez, Morocco
| | - Ahmed Dadouch
- Sidi Mohamed Ben Abdellah University, Faculty of Sciences Dhar EL Mahraz, Fez, Morocco
| | - Abdelmajid Maghnouj
- Sidi Mohamed Ben Abdellah University, Faculty of Sciences Dhar EL Mahraz, Fez, Morocco
| | - Assiya Lemmassi
- Sidi Mohamed Ben Abdellah University, Higher School of Technology, Fez, Morocco
| | - Maroine Tahiri
- Hassan First University, Higher Institute of Health Sciences, Settat, Morocco
| | - Youssef El-Ouardi
- Sidi Mohamed Ben Abdellah University, Faculty of Sciences Dhar EL Mahraz, Fez, Morocco
| | - Ibrahim Ait Ouaggou
- University Mohammed First, National School of Applied Sciences, Oujda, Morocco
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Inoue Y, Itoh H, Shiibashi N, Sasa R, Mitsui K. Sample Size and Estimation of Standard Radiation Doses for Pediatric Brain CT. Tomography 2022; 8:2486-2497. [PMID: 36287806 PMCID: PMC9612354 DOI: 10.3390/tomography8050207] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/24/2022] [Accepted: 09/29/2022] [Indexed: 11/04/2022] Open
Abstract
Estimation of the standard radiation dose at each imaging facility is required for radiation dose management, including establishment and utilization of the diagnostic reference levels. We investigated methods to estimate the standard dose for pediatric brain computed tomography (CT) using a small number of data. From 980 pediatric brain CT examinations, 25, 50, and 100 examinations were randomly extracted to create small, medium, and large datasets, respectively. The standard dose was estimated by applying grouping and curve-fitting methods for 20 datasets of each sample size. For the grouping method, data were divided into groups according to age or body weight, and the standard dose was defined as a median value in each group. For the curve-fitting methods, logarithmic, power, and bilinear functions were fitted to plots of radiation dose against age or weight, and the standard dose was calculated at the designated age or weight using the derived equation. When the sample size was smaller, the random variations of the estimated standard dose were larger. Better estimation of the standard dose was achieved with the curve-fitting methods than with the grouping method. Power fitting appeared to be more effective than logarithmic and bilinear fittings for suppressing random variation. Determination of the standard dose for pediatric brain CT by the curve-fitting method is recommended to improve radiation dose optimization at facilities performing the imaging procedure infrequently.
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Affiliation(s)
- Yusuke Inoue
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan
- Correspondence:
| | - Hiroyasu Itoh
- Department of Radiology, Kitasato University Hospital, Sagamihara 252-0374, Kanagawa, Japan
| | - Nao Shiibashi
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan
| | - Ryosuke Sasa
- Department of Radiology, Kitasato University Hospital, Sagamihara 252-0374, Kanagawa, Japan
| | - Kohei Mitsui
- Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, Kanagawa, Japan
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Kamdem EF, Samba ON, Manemo CT, Kouam BBF, Abogo S, Tambe J, Amougou JCM, Guegang E, Zeh OF, Moifo B, Nguemgne C, Nana NFN, Fotue AJ. ESTABLISHMENT OF LOCAL DIAGNOSTIC REFERENCE LEVEL FOR ROUTINE PAEDIATRIC COMPUTED TOMOGRAPHY EXAMINATIONS IN BAFOUSSAM WEST CAMEROON. RADIATION PROTECTION DOSIMETRY 2022; 198:815-820. [PMID: 35718757 DOI: 10.1093/rpd/ncac143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 04/28/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
The main purpose of this study was to determine local diagnostic reference level (LDRL) for routine computed tomography (CT) examination in Bafoussam, western Cameroon. The exposure parameters and dose quantities were collected manually. This retrospective, evaluative and comparative study was conducted to determine LDRLs for routine head CT examination in Bafoussam, to optimize these procedures in the region. The 75th percentile values of the calculated volume CT dose index (CTDIvol) and dose length product (DLP) were proposed as LDRL. The sample was classified in four age groups: < 1, 1-5, 5-10 and 10-15 y. The LDRLs obtained for the four age groups were: 24 mGy and 381.32 mGy.cm, 42.5 mGy and 875.55 mGy.cm, 45.85 mGy and 939.62 mGy.cm, 57.12 mGy and 1222.3 mGy.cm, respectively. The 75th percentile CTDIvol and DLP dose values for this study are higher than international values. We propose a coordinating discussions and collaboration about patient's and specific equipment's change information's, between radiologists, medical imaging technicians and medical physicist, which can reduce absorbed doses and improved medical practice in hospitals.
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Affiliation(s)
- Eddy Fotso Kamdem
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
| | | | - Cedric Tetchoka Manemo
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
| | | | - Serge Abogo
- Department of Radiology, National Social Insurance Fund Hospital, Yaoundé, Cameroon
| | - Joshua Tambe
- Department of Radiology, Limbe Regional Hospital, Limbe, Cameroon
| | | | - Emilienne Guegang
- Department of Radiography, Yaoundé General Hospital, Yaoundé, Cameroon
| | - Odile Fernande Zeh
- Department of Radiology, Yaounde Gynaeco-Obstetric and Pediatric Hospital, Yaoundé, Cameroon
| | - Boniface Moifo
- Department of Radiology, Yaounde Gynaeco-Obstetric and Pediatric Hospital, Yaoundé, Cameroon
| | | | | | - Alain Jervé Fotue
- Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 479, Dschang, Cameroon
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Radiation Dose Management in Pediatric Brain CT According to Age and Weight as Continuous Variables. Tomography 2022; 8:985-998. [PMID: 35448713 PMCID: PMC9027691 DOI: 10.3390/tomography8020079] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/26/2022] [Accepted: 03/31/2022] [Indexed: 12/28/2022] Open
Abstract
The diagnostic reference levels (DRLs) for pediatric brain computed tomography (CT) are provided for groups divided according to age. We investigated the relationships of radiation dose indices (volume CT dose index and dose length product) with age and weight, as continuous variables, in pediatric brain CT. In a retrospective analysis, 980 pediatric brain CT examinations were analyzed. Curve fitting was performed for plots of the CT dose indices versus age and weight, and equations to estimate age- and weight-dependent standard dose indices were derived. Standard dose indices were estimated using the equations, and the errors were calculated. The results showed a biphasic increase in dose indices with increasing age and weight, characterized by a rapid initial and subsequent slow increase. Logarithmic, power, and bilinear functions were well fitted to the plots, allowing estimation of standard dose indices at an arbitrary age or weight. Error analysis suggested that weight was mildly better than age and that the best results were obtained with the bilinear function. Curve fitting of the relationship between CT dose indices and age or weight facilitates the determination of standard dose indices in pediatric brain CT at each facility and is expected to aid the establishment and application of the DRLs.
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Kadavigere R, Sukumar S. Estimation of radiation dose and establishment of local diagnostic reference levels for computed tomography of head in pediatric population. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2022; 30:983-991. [PMID: 35786667 DOI: 10.3233/xst-221172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
BACKGROUND Pediatric population is more sensitive to the effects of radiation than adults. Establishing diagnostic reference level (DRL) is an efficient dose optimization technique implemented by many countries for reducing radiation dose during Computed Tomography (CT) examinations. OBJECTIVES To estimate radiation dose and establish a new local diagnostic reference level for CT head examination in the pediatric population. MATERIALS AND METHODS We prospectively recruited 143 pediatric patients referred for CT head examination with age ranging from 0-5 years old. All patients had undergone CT head examination using the standard pediatric head protocol. Volumetric CT dose index (CTDIvol) and dose length product (DLP) were recorded. The effective dose was first calculated. Then, 75th percentile of dose indices was calculated to establish DRLs. RESULTS DRLs in terms of CTDIvol and DLP are 23.84 mGy, 555.99 mGy.cm for patients <1 years old and 28.65 mGy, 794.99 mGy.cm for patients from 1-5 years old, respectively. Mean effective doses for <1 years old patients and 1-5 years old patients are 2.91 mSv and 2.78 mSv respectively. CONCLUSION The study concludes that DRL in terms of CTDIvol is lower but DRL in terms of DLP and the effective dose is higher compared to a few other studies which necessitate the need for dose optimization.
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Affiliation(s)
- Rajagopal Kadavigere
- Department of Radio diagnosis and Imaging, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Suresh Sukumar
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, India
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Almén A, Guðjónsdóttir J, Heimland N, Højgaard B, Waltenburg H, Widmark A. Paediatric diagnostic reference levels for common radiological examinations using the European guidelines. Br J Radiol 2021; 95:20210700. [PMID: 34898256 PMCID: PMC8822550 DOI: 10.1259/bjr.20210700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The purpose of this study was to explore the feasibility to determine regional diagnostic reference levels (RDRLs) for paediatric conventional and CT examinations using the European guidelines and to compare RDRLs derived from weight and age groups, respectively. METHODS Data were collected from 31 hospitals in 4 countries, for 7 examination types for a total of 2978 patients. RDRLs were derived for each weight and age group, respectively, when the total number of patients exceeded 15. RESULTS It was possible to derive RDRLs for most, but not all, weight-based and age-based groups for the seven examinations. The result using weight-based and age-based groups differed substantially. The RDRLs were lower than or equal to the European and recently published national DRLs. CONCLUSION It is feasible to derive RDRLs. However, a thorough review of the clinical indications and methodologies has to be performed previous to data collection. This study does not support the notion that DRLs derived using age and weight groups are exchangeable. ADVANCES IN KNOWLEDGE Paediatric DRLs should be derived using weight-based groups with access to the actual weight of the patients. DRLs developed using weight differ markedly from those developed with the use of age. There is still a need to harmonize the method to derive solid DRLs for paediatric radiological examinations.
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Affiliation(s)
- Anja Almén
- Department of Radiation Protection, Swedish Radiation Safety Authority, Stockholm, Sweden.,Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Jónína Guðjónsdóttir
- Icelandic Radiation Safety Authority, Reykjavik, Iceland.,Department of Radiography, Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - Nils Heimland
- Department of Radiation Protection and Measurement Services, Norwegian Radiation and Nuclear Safety Authority, Bærum, Norway
| | - Britta Højgaard
- Radiation Protection, Danish Health Authority, Copenhagen, Denmark
| | - Hanne Waltenburg
- Radiation Protection, Danish Health Authority, Copenhagen, Denmark
| | - Anders Widmark
- Department of Radiation Protection and Measurement Services, Norwegian Radiation and Nuclear Safety Authority, Bærum, Norway.,Department of Health Sciences, Norwegian University of Science and Technology, Gjøvik, Norway
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Delakis I, Kelly C. Use of weight-based vs age-based groupings in the study of typical values of air kerma area product (P KA) for paediatric radiographs of chest and abdomen. Br J Radiol 2021; 94:20210331. [PMID: 34541860 DOI: 10.1259/bjr.20210331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To compare age groupings versus weight groupings in the calculation of typical air kerma area product (PKA) values in paediatric X-ray exams of chest and abdomen in our hospital. METHODS Data were analysed from 687 abdominal and 1374 chest X-ray examinations. The PKA of exams was extracted with Radimetrics, and patient weights were collected from electronic records. Data were organised in different age groups and typical PKA values were estimated. The process was repeated by organising data in different weight groups. RESULTS Typical PKA values for the four younger age groups (<1m, 1m - < 4y, 4y - < 10y and 10y - < 14y) were comparable to typical values for their equivalent weight groups (<5 kg, 5-15 kg, 15-30 kg and 30-50 kg, respectively). However, typical PKA values at the late adolescent age group (14y - < 18y) were much lower than its equivalent weight group (>50 kg). CONCLUSIONS Age and weight groupings were found at our site to be interchangeable for the calculation of typical paediatric PKA values. The only exception was the late adolescent group, whose weight distribution can account for the difference in typical PKA results within its equivalent weight group. ADVANCES IN KNOWLEDGE In calculating typical PKA values for radiological paediatric body examinations, departments must ascertain if using age groups, which is typical practice, is equivalent to using weight groups. Otherwise, results may misrepresent local practice.
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Affiliation(s)
- Ioannis Delakis
- Sidra Medicine, Doha, Qatar.,Weill Cornell Medical College, Radiology, NY, United States
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Moghadam N, Lecomte R, Mercure S, Rehani MM, Nassiri MA. Simplified size adjusted dose reference levels for adult CT examinations: A regional study. Eur J Radiol 2021; 142:109861. [PMID: 34280596 DOI: 10.1016/j.ejrad.2021.109861] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/30/2021] [Accepted: 07/06/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate retrospective classification of adult patients into small, average, and large based on effective diameter (EDia) from localizer image of computed tomography (CT) scans and to develop regional diagnostic reference levels (DRLs) and achievable doses (AD). METHOD The patients falling within the mean ± standard deviation (SD) of EDia were classified as average; those below this range as small and above as large. The CTDIvol,dose-length-product (DLP) and size-specific dose estimates (SSDE) of all adult patients undergoing CT examinations in 8 CT facilities for 11 months (Dec. 2019 - Oct. 2020) were evaluated. The 75th and 50th percentile values were compared with national and international values. RESULTS Of the total of 69,434 CT examinations, nearly 80% fell within average size. The 75th percentile values of CTDIvol and DLP for small patients for abdomen-pelvic exams were nearly half of average sized patients. Similarly, the 75th percentile values for large patients were nearly double. Similar findings were not found for chest exams. Analysis of image quality and dose factors such as noise, mean axial length, slice thickness, mean number of sequences, use of iterative reconstruction and tube current modulation (TCM) resulted in identification of opportunities for improvement and optimization of different CT facilities. CONCLUSIONS DRLs for adult patients were found to vary widely with patient size and thus establishing DRLs only for standard sized patient is not adequate. Simplified and intuitive methods for size classification was shown to provide meaningful information for optimization for patients outside the standard size adult.
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Affiliation(s)
- Narjes Moghadam
- Centre de recherche du Centre hospitalier universitaire de Sherbrooke (CRCHUS), Sherbrooke, Québec, Canada; Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS), Sherbrooke, Québec, Canada.
| | - Roger Lecomte
- Centre de recherche du Centre hospitalier universitaire de Sherbrooke (CRCHUS), Sherbrooke, Québec, Canada; Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada
| | - Stéphane Mercure
- Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS), Sherbrooke, Québec, Canada
| | - Madan M Rehani
- Radiology Department, Massachusetts General Hospital, Boston, MA, USA
| | - Moulay Ali Nassiri
- Centre de recherche du Centre hospitalier universitaire de Sherbrooke (CRCHUS), Sherbrooke, Québec, Canada; Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS), Sherbrooke, Québec, Canada; Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Canada
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Hwang JY, Choi YH, Yoon HM, Ryu YJ, Shin HJ, Kim HG, Lee SM, You SK, Park JE. Establishment of Local Diagnostic Reference Levels of Pediatric Abdominopelvic and Chest CT Examinations Based on the Body Weight and Size in Korea. Korean J Radiol 2021; 22:1172-1184. [PMID: 33856132 PMCID: PMC8236355 DOI: 10.3348/kjr.2020.0890] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/11/2020] [Accepted: 09/16/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The purposes of this study were to analyze the radiation doses for pediatric abdominopelvic and chest CT examinations from university hospitals in Korea and to establish the local diagnostic reference levels (DRLs) based on the body weight and size. MATERIALS AND METHODS At seven university hospitals in Korea, 2494 CT examinations of patients aged 15 years or younger (1625 abdominopelvic and 869 chest CT examinations) between January and December 2017 were analyzed in this study. CT scans were transferred to commercial automated dose management software for the analysis after being de-identified. DRLs were calculated after grouping the patients according to the body weight and effective diameter. DRLs were set at the 75th percentile of the distribution of each institution's typical values. RESULTS For body weights of 5, 15, 30, 50, and 80 kg, DRLs (volume CT dose index [CTDIvol]) were 1.4, 2.2, 2.7, 4.0, and 4.7 mGy, respectively, for abdominopelvic CT and 1.2, 1.5, 2.3, 3.7, and 5.8 mGy, respectively, for chest CT. For effective diameters of < 13 cm, 14-16 cm, 17-20 cm, 21-24 cm, and > 24 cm, DRLs (size-specific dose estimates [SSDE]) were 4.1, 5.0, 5.7, 7.1, and 7.2 mGy, respectively, for abdominopelvic CT and 2.8, 4.6, 4.3, 5.3, and 7.5 mGy, respectively, for chest CT. SSDE was greater than CTDIvol in all age groups. Overall, the local DRL was lower than DRLs in previously conducted dose surveys and other countries. CONCLUSION Our study set local DRLs in pediatric abdominopelvic and chest CT examinations for the body weight and size. Further research involving more facilities and CT examinations is required to develop national DRLs and update the current DRLs.
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Affiliation(s)
- Jae Yeon Hwang
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, College of Medicine, Pusan National University, Yangsan, Korea.
| | - Young Hun Choi
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hee Mang Yoon
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
| | - Young Jin Ryu
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Hyun Joo Shin
- Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun Gi Kim
- Department of Radiology, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - So Mi Lee
- Department of Radiology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Sun Kyung You
- Department of Radiology, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea
| | - Ji Eun Park
- Department of Radiology, Ajou University Hospital, School of Medicine, Ajou University, Suwon, Korea
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Kharita MH, AlNaemi H, Kini V, Alkhazzam S, Rehani MM. Development of image quality related reference doses called acceptable quality doses (AQD) in paediatric CT exams in Qatar. Eur Radiol 2021; 31:3098-3105. [PMID: 33175202 PMCID: PMC8043894 DOI: 10.1007/s00330-020-07375-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/10/2020] [Accepted: 10/05/2020] [Indexed: 01/10/2023]
Abstract
OBJECTIVES To describe first experience of integrating assessment of image quality in paediatric X-ray computed tomography (CT) with analysis of the radiation dose indices to develop reference doses called acceptable quality dose (AQD). METHODS Image quality was scored by the radiologists at a tertiary care hospital in Qatar on a scale of 0 to 4 using the recently published scoring criteria. The patients undergoing head, chest and abdomen CT were divided in different weight groups as follows: < 5 kg, 5-< 15 kg, 15-< 30 kg, 30-< 50 kg, 50-< 80 kg and > 80 kg. The images that were clinically acceptable (score of 3) were included for assessment of median values of CTDIvol and DLP to obtain AQDs in different weight groups. RESULTS After initial training in image quality scoring of CT images of 49 patients by three radiologists, the study on 715 patients indicated 665 studies (93%) were clinically acceptable as per scoring criteria. The median CTDIvol values for the above weight groups were 16, 20, 22, 22, 27 and 27 mGy and the median DLP values for these weight groups were 271, 377, 463, 486, 568 and 570 mGy cm, respectively, for head CT. Similar values are presented for chest and abdomen CTs. CONCLUSIONS The first ever experience of starting with image quality assessment and integrating it with analysis of dose indices to obtain AQD values shall provide a workable model for others and values for comparison within the facility and in other facilities leading to optimisation. KEY POINTS • The first study to integrate image quality assessment with analysis of patient dose indices shows feasibility for routine practice in other centres. • The values of acceptable quality dose (AQD) were provided for head, chest and abdomen CT of children divided into weight groups rather than age. They shall act as reference values for future studies. • Verification of our findings on proportional increase in exposure parameters (CTDIvol and DLP) with weight by other investigators shall be helpful.
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Affiliation(s)
- Mohammad Hassan Kharita
- Hamad Medical Corporation, Occupational Health and Safety, Radiation Safety Section, Doha, Qatar.
| | - Huda AlNaemi
- Hamad Medical Corporation, Occupational Health and Safety, Radiation Safety Section, Doha, Qatar
| | - Vishwanatha Kini
- Hamad Medical Corporation, Occupational Health and Safety, Radiation Safety Section, Doha, Qatar
| | - Shady Alkhazzam
- Hamad Medical Corporation, Occupational Health and Safety, Radiation Safety Section, Doha, Qatar
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Delis H, Homolka P, Chapple C, Costa P, Attalla E, Lubis L, Sackey T, Fahey F, Lassmann M, Poli G. Developing and implementing a multi-modality imaging optimization study in paediatric radiology: Experience and recommendations from an IAEA coordinated research project. Phys Med 2021; 82:255-265. [DOI: 10.1016/j.ejmp.2021.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 02/04/2021] [Accepted: 02/15/2021] [Indexed: 11/15/2022] Open
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Kawamoto K, Fukushima Y, Matsuda A, Nakata M. EVALUATION OF ORGAN DOSE BASED ON PATIENT DATA IN EAST ASIAN DESCENT PEDIATRIC HEAD CT EXAMINATIONS. RADIATION PROTECTION DOSIMETRY 2020; 192:335-340. [PMID: 33326990 DOI: 10.1093/rpd/ncaa200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/20/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
The purpose of this study was to investigate other indices estimating absorbed dose for eye lens and brain, using clinical images of East Asian pediatric patients. We simulated head computed tomography (CT ) examinations in 104 pediatric patients. Effective diameter (deff) and water equivalent diameter (dw) were measured on clinical images. Various size metrics and age were compared with absorbed dose normalised by CTDIvol (nD). The nD was estimated for eye and brain. The nD tended to decrease with advancing age. R2 between age and nD were 0.38 and 0.31 for eye and brain, respectively. Increasing head diameters decreased each nD. R2 between deff and dw, and nD were 0.20-0.24 and 0.51-0.53 for eye and brain, respectively. Head sizes allowed us to estimate absorbed dose in brain CT on East Asian pediatric patients. Scanning parameters for pediatric head CT may need to be based on individual patient information.
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Affiliation(s)
- Keishin Kawamoto
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku Kyoto 606-8507, Japan
| | - Yasuhiro Fukushima
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku Kyoto 606-8507, Japan
| | - Akira Matsuda
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku Kyoto 606-8507, Japan
| | - Manabu Nakata
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku Kyoto 606-8507, Japan
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Long-term experience and analysis of data on diagnostic reference levels: the good, the bad, and the ugly. Eur Radiol 2019; 30:1127-1136. [PMID: 31529257 DOI: 10.1007/s00330-019-06422-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 07/25/2019] [Accepted: 08/12/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVES To analyze 11-year data of France for temporal trends in dose indices and dose optimization and draw lessons for those who are willing to work on creation and update of diagnostic reference levels (DRLs). METHODS The data from about 3000 radiology departments leading to about 750,000 imaging exams between 2004 and 2015 was analyzed, and patterns of reductions in dose for those below and above the DRLs were estimated and correlated with technology change. RESULTS Dose optimization achieved was important and significant in departments which were above or just below the DRL (p = .006) but not in those which were around half of the DRL values. The decrease in 75th percentile value of Kerma air product (KAP) for chest radiography by 27.4% between 2004 and 2015 was observed with the number of flat panel detectors increase from 6 to 43%. A good correlation between the detector type distribution and the level of patient radiation exposure is observed. Otherwise, setting DRLs for standard-sized patient excludes patients lower and higher weighted than "standard." CONCLUSIONS The concept of DRL may become obsolete unless lessons drawn from the experience of users are taken into account. While establishing DRLs should be part of the regulations, setting up and updating values should be governed by bodies whose decision-making cycle is short, at the most 1 year. A local rather than national approach, taking into account body habitus and image quality, needs to be organized. KEY POINTS • The technology changes faster than regulations. Requirement of DRL establishment should be part of the regulations; however, setting and updating values should be the role of professional societies. • The concept of DRL, highlighting the 75th percentile values and dedicated to standard-sized adult, misses optimization opportunities in the majority of patients who are below the 75th percentile value and outside the range of standard-sized adult. • The ugly aspects of the DRL concept include its non-applicability to individuals, no customization to clinical indications, and lack of consideration of image quality.
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Alejo L, Corredoira E, Sánchez-Muñoz F, Huerga C, Aza Z, Plaza-Núñez R, Serrada A, Bret-Zurita M, Parrón M, Prieto-Areyano C, Garzón-Moll G, Madero R, Guibelalde E. Radiation dose optimisation for conventional imaging in infants and newborns using automatic dose management software: an application of the new 2013/59 EURATOM directive. Br J Radiol 2018; 91:20180022. [PMID: 29537302 PMCID: PMC6223298 DOI: 10.1259/bjr.20180022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/01/2018] [Accepted: 03/12/2018] [Indexed: 01/24/2023] Open
Abstract
Objective: The new 2013/59 EURATOM Directive (ED) demands dosimetric optimisation procedures without undue delay. The aim of this study was to optimise paediatric conventional radiology examinations applying the ED without compromising the clinical diagnosis. METHODS Automatic dose management software (ADMS) was used to analyse 2678 studies of children from birth to 5 years of age, obtaining local diagnostic reference levels (DRLs) in terms of entrance surface air kerma. Given local DRL for infants and chest examinations exceeded the European Commission (EC) DRL, an optimisation was performed decreasing the kVp and applying the automatic control exposure. To assess the image quality, an analysis of high-contrast resolution (HCSR), signal-to-noise ratio (SNR) and figure of merit (FOM) was performed, as well as a blind test based on the generalised estimating equations method. RESULTS For newborns and chest examinations, the local DRL exceeded the EC DRL by 113%. After the optimisation, a reduction of 54% was obtained. No significant differences were found in the image quality blind test. A decrease in SNR (-37%) and HCSR (-68%), and an increase in FOM (42%), was observed. CONCLUSION ADMS allows the fast calculation of local DRLs and the performance of optimisation procedures in babies without delay. However, physical and clinical analyses of image quality remain to be needed to ensure the diagnostic integrity after the optimisation process. Advances in knowledge: ADMS are useful to detect radiation protection problems and to perform optimisation procedures in paediatric conventional imaging without undue delay, as ED requires.
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Affiliation(s)
- L Alejo
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - E Corredoira
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - F Sánchez-Muñoz
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - C Huerga
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - Z Aza
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - R Plaza-Núñez
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - A Serrada
- Department of Medical Physics, La Paz University Hospital, Madrid, Spain
| | - M Bret-Zurita
- Department of Paediatric Radiology, La Paz University Hospital, Madrid, Spain
| | - M Parrón
- Department of Paediatric Radiology, La Paz University Hospital, Madrid, Spain
| | - C Prieto-Areyano
- Department of Paediatric Radiology, La Paz University Hospital, Madrid, Spain
| | - G Garzón-Moll
- Department of Paediatric Radiology, La Paz University Hospital, Madrid, Spain
| | - R Madero
- Department of Biostatistics, La Paz University Hospital, Madrid, Spain
| | - E Guibelalde
- Department of Radiology, Complutense University, Madrid, Spain
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15
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Journy NMY, Dreuil S, Boddaert N, Chateil JF, Defez D, Ducou-le-Pointe H, Garcier JM, Guersen J, Habib Geryes B, Jahnen A, Lee C, Payen-de-la-Garanderie J, Pracros JP, Sirinelli D, Thierry-Chef I, Bernier MO. Individual radiation exposure from computed tomography: a survey of paediatric practice in French university hospitals, 2010-2013. Eur Radiol 2018; 28:630-641. [PMID: 28836026 DOI: 10.1007/s00330-017-5001-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 02/06/2023]
Abstract
OBJECTIVES To describe computed tomography (CT) scanning parameters, volume CT dose index (CTDIvol) and dose-length product (DLP) in paediatric practice and compare them to current diagnostic reference levels (DRLs). METHODS The survey was conducted in radiology departments of six major university hospitals in France in 2010-2013. Data collection was automatised to extract and standardise information on scanning parameters from DICOM-header files. CTDIvol and DLP were estimated based on Monte Carlo transport simulation and computational reference phantoms. RESULTS CTDIvol and DLP were derived for 4,300 studies, four age groups and 18 protocols. CTDIvol was lower in younger patients for non-head scans, but did not vary with age for routine head scans. Ratios of 95th to 5th percentile CTDIvol values were 2-4 for most body parts, but 5-7 for abdominal examinations and 4-14 for mediastinum CT with contrast, depending on age. The 75th percentile CTDIvol values were below the national DRLs for chest (all ages) and head and abdominal scans (≥10 years). CONCLUSION The results suggest the need for a better optimisation of scanning parameters for routine head scans and infrequent protocols with patient age, enhanced standardisation of practices across departments and revision of current DRLs for children. KEY POINTS • CTDIvol varied little with age for routine head scans. • CTDIvol was lowest in youngest children for chest or abdominal scans. • Individual and inter-department variability warrant enhanced standardisation of practices. • Recent surveys support the need for revised diagnostic reference levels. • More attention should be given to specific protocols (sinuses, neck, spine, mediastinum).
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Affiliation(s)
- Neige M Y Journy
- Laboratoire d'épidémiologie des rayonnements ionisants, Unité Radioprotection de l'Homme, Institut de Radioprotection et de Sûreté Nucléaire, 31 avenue de la Division Leclerc, 92260, Fontenay-aux-Roses, France.
- Radiation Epidemiology Branch, Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Bethesda, MD, 20892-9760, USA.
| | - Serge Dreuil
- Unité d'expertise en radioprotection médicale, Institut de Radioprotection et de Sûreté Nucléaire, 31 avenue de la Division Leclerc, 92260, Fontenay-aux-Roses, France
| | - Nathalie Boddaert
- Service de radiologie pédiatrique, INSERM U1000, UMR 1163, Institut Imagine, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Universitaire Necker Enfants Malades, 149 rue de Sèvres, 75743, Paris Cedex 15, France
- PRES Sorbonne Paris, Cité Université René Descartes, 190 avenue de France, 75013, Paris, France
| | - Jean-François Chateil
- Service de radiologie et d'imagerie anténatale, de l'enfant et de la femme, Groupe Hospitalier Pellegrin, Centre Hospitalier Universitaire de Bordeaux, place Amélie Raba-Léon, 33000, Bordeaux, France
| | - Didier Defez
- Service de Physique Médicale, Centre Hospitalier Lyon Sud, 165 Chemin du Grand Revoyet, 69495, Pierre-Benite, France
| | - Hubert Ducou-le-Pointe
- Service de Radiologie, Hôpital d'Enfants Armand-Trousseau, 26 avenue du Dr A. Netter, 75012, Paris, France
| | - Jean-Marc Garcier
- Service de radiologie, Centre Hospitalier Universitaire Estaing, 1 place Lucie-Aubrac, 63003, Clermont-Ferrand Cedex 1, France
| | - Joël Guersen
- Pôle Imagerie et Radiologie Interventionnelle, Centre Hospitalier Universitaire Gabriel Montpied, 58 rue Montalembert, 63003, Clermont Ferrand cedex 1, France
| | - Bouchra Habib Geryes
- Direction des affaires médicales, de la qualité et la relation avec les usagers, Hôpital Universitaire Necker Enfants Malades, 149 rue de Sèvres, 75743, Paris Cedex 15, France
| | - Andreas Jahnen
- Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362, Esch/Alzette, Luxembourg, Luxembourg
| | - Choonsik Lee
- Radiation Epidemiology Branch, Division of Cancer Epidemiology & Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Bethesda, MD, 20892-9760, USA
| | | | - Jean-Pierre Pracros
- Service d'imagerie pédiatrique, Hôpital Femme Mère Enfants, Groupe Hospitalier Est, 59 Boulevard Pinel, 69500, Bron, France
| | - Dominique Sirinelli
- Service de radiologie pediatrique, Hôpital Clocheville, Centre Hospitalier Régional Universitaire de Tours, 49 boulevard Béranger, 37000, Tours, France
| | - Isabelle Thierry-Chef
- Section of Environment and Cancer, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon cedex 08, France
| | - Marie-Odile Bernier
- Laboratoire d'épidémiologie des rayonnements ionisants, Unité Radioprotection de l'Homme, Institut de Radioprotection et de Sûreté Nucléaire, 31 avenue de la Division Leclerc, 92260, Fontenay-aux-Roses, France
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Salama DH, Vassileva J, Mahdaly G, Shawki M, Salama A, Gilley D, Rehani MM. Establishing national diagnostic reference levels (DRLs) for computed tomography in Egypt. Phys Med 2017; 39:16-24. [DOI: 10.1016/j.ejmp.2017.05.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/30/2017] [Accepted: 05/04/2017] [Indexed: 01/12/2023] Open
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Muhogora W, Rehani MM. Review of the current status of radiation protection in diagnostic radiology in Africa. J Med Imaging (Bellingham) 2017. [PMID: 28630886 DOI: 10.1117/1.jmi.4.3.031202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aim of this paper is to review the available published studies from African countries on patient doses and medical radiation protection and identify strengths, weaknesses, and challenges. Papers on radiation doses to patients published until 2016 pertaining to studies in African countries were reviewed. Radiography, interventional radiology, computed tomography (CT), and mammography modalities were covered. In radiography, the entrance surface air kerma values were below the established diagnostic reference levels (DRLs) provided by the International Atomic Energy Agency, European Commission, and National Council on Radiation Protection and Measurements. Patient and staff doses in interventional procedures were not on the higher side when compared with other published reports from developed countries. The dose length product values in CT in many situations were higher than established DRLs. In mammography, the variations of clinical image quality and dose to standard breast between African countries and other countries were insignificant. In conclusion, like in any continent, not all countries in Africa are active, but some have produced good results. The potential for optimization of radiation protection using simple and inexpensive techniques has been demonstrated. The lack of medical physicists is one of the important challenges.
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Affiliation(s)
| | - Madan M Rehani
- Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, United States.,Duke University, Department of Radiology, Durham, North Carolina, United States
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Rehani MM. Dose surveys and DRLs: critical look and way forward. RADIATION PROTECTION DOSIMETRY 2015; 165:67-69. [PMID: 25809110 DOI: 10.1093/rpd/ncv063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The main purpose of dose surveys has been to detect and bring down wide variation in radiation doses for any particular radiological examination and to avoid doses that are on higher side. Diagnostic reference levels (DRLs) have been used for over two decades as an aid in this objective. With very limited success that has been achieved through DRL, the author has recently described a new term 'acceptable quality dose' (AQD) that is aimed at optimisation within the DRL, is facility initiated and takes into account all three important parameters-image quality, dose and patient's body build. It is hoped that AQD will be found easy to establish, will be a useful tool to achieve optimisation in the facilities and will serve as the standard dose.
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Affiliation(s)
- Madan M Rehani
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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19
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Vassileva J, Rehani M, Kostova-Lefterova D, Al-Naemi HM, Al Suwaidi JS, Arandjic D, Bashier EHO, Kodlulovich Renha S, El-Nachef L, Aguilar JG, Gershan V, Gershkevitsh E, Gruppetta E, Hustuc A, Jauhari A, Kharita MH, Khelassi-Toutaoui N, Khosravi HR, Khoury H, Kralik I, Mahere S, Mazuoliene J, Mora P, Muhogora W, Muthuvelu P, Nikodemova D, Novak L, Pallewatte A, Pekarovič D, Shaaban M, Shelly E, Stepanyan K, Thelsy N, Visrutaratna P, Zaman A. A study to establish international diagnostic reference levels for paediatric computed tomography. RADIATION PROTECTION DOSIMETRY 2015; 165:70-80. [PMID: 25836685 DOI: 10.1093/rpd/ncv116] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.
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Affiliation(s)
- J Vassileva
- International Atomic Energy Agency, Vienna, Austria
| | - M Rehani
- Harvard Medical School and Massachusetts General Hospital, Boston, USA
| | | | | | - J S Al Suwaidi
- Medical Education Department, Dubai Health Authority, Dubai, UAE
| | - D Arandjic
- Radiation Protection Department, Vinca Institute of Nuclear Sciences, Belgrade, Serbia
| | | | | | - L El-Nachef
- Lebanese Atomic Eneregy Commission, Beirut, Lebanon
| | - J G Aguilar
- National Institute for Nuclear Research, Carretera Mexico-Toluca, La Marquesa, Ocoyoacac, Mexico
| | - V Gershan
- Institute of Physics, Ss Cyril and Methodius University, Skopje, The former Yugoslav Republic of Macedonia
| | | | | | - A Hustuc
- National Centre of Public Health, Chisinau, Republic of Moldova
| | - A Jauhari
- Pusat Kajian Radiografi dan Imajing, Depok, Indonesia
| | | | - N Khelassi-Toutaoui
- Département de Physique Médicale, Centre de Recherche Nucléaire D'Alger, Algiers, Algiers
| | - H R Khosravi
- National Radiation Protection Department, Iranian Nuclear Regulatory Authority, Tehran, Iran
| | - H Khoury
- Universidade Federal de Pernambuco, Cidade Universitaria, Recife PE, Brazil
| | - I Kralik
- State Office for Radiological and Nuclear Safety, Zagreb, Croatia
| | - S Mahere
- Children Clinical University Hospital, Riga, Latvia
| | - J Mazuoliene
- Hospital of Lithuanian University of Health Science Kauno Klinikos, Kaunas, Lithuania
| | - P Mora
- Centro de Investigación en Ciencias Atómicas, Nucleares y Moleculares, Universidad de Costa Rica, San José, Costa Rica
| | - W Muhogora
- Tanzania Atomic Energy Commission, Arusha, Tanzania
| | - P Muthuvelu
- Ministry of Health Malaysia, Putrajaya Wilayah Persekutuan, Malaysia
| | - D Nikodemova
- Slovak Medical University, Limbova, Bratislava, Slovakia
| | - L Novak
- National Radiation Protection Institute, Prague, Czech Republic
| | - A Pallewatte
- Department of Radiology, The National Hospital of Sri Lanka, Colombo, Sri Lanka
| | - D Pekarovič
- Clinical Radiology Institute, University Medical Center, Ljubljana, Slovenia
| | - M Shaaban
- Al-Sabah Hospital, Kuwait City, Kuwait
| | - E Shelly
- Ministry of Health, Medical Technology and Infrastructure Administration, Jerusalem, Israel
| | - K Stepanyan
- Research Center of Radiation Medicine and Burns, Yerevan, Armenia
| | - N Thelsy
- Radiologist Ministry of Health, Yangon, Myanmar
| | - P Visrutaratna
- Faculty of Medicine, Department of Radiology, Chiang Mai University, Chiang Mai, Thailand
| | - A Zaman
- Institute of Nuclear Medicine and Oncology, PAEC, Lahore, Pakistan
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