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Viry A, Vitzthum V, Monnin P, Bize J, Rotzinger D, Racine D. Optimization of CT pulmonary angiography for pulmonary embolism using task-based image quality assessment and diagnostic reference levels: A multicentric study. Phys Med 2024; 121:103365. [PMID: 38663347 DOI: 10.1016/j.ejmp.2024.103365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/12/2024] [Accepted: 04/19/2024] [Indexed: 05/12/2024] Open
Abstract
PURPOSE To establish size-specific diagnostic reference levels (DRLs) for pulmonary embolism (PE) based on patient CT examinations performed on 74 CT devices. To assess task-based image quality (IQ) for each device and to investigate the variability of dose and IQ across different CTs. To propose a dose/IQ optimization. METHODS 1051 CT pulmonary angiography dose data were collected. DRLs were calculated as the 75th percentile of CT dose index (CTDI) for two patient categories based on the thoracic perimeters. IQ was assessed with two thoracic phantom sizes using local acquisition parameters and three other dose levels. The area under the ROC curve (AUC) of a 2 mm low perfused vessel was assessed with a non-prewhitening with eye-filter model observer. The optimal IQ-dose point was mathematically assessed from the relationship between IQ and dose. RESULTS The DRLs of CTDIvol were 6.4 mGy and 10 mGy for the two patient categories. 75th percentiles of phantom CTDIvol were 6.3 mGy and 10 mGy for the two phantom sizes with inter-quartile AUC values of 0.047 and 0.066, respectively. After the optimization, 75th percentiles of phantom CTDIvol decreased to 5.9 mGy and 7.55 mGy and the interquartile AUC values were reduced to 0.025 and 0.057 for the two phantom sizes. CONCLUSION DRLs for PE were proposed as a function of patient thoracic perimeters. This study highlights the variability in terms of dose and IQ. An optimization process can be started individually and lead to a harmonization of practice throughout multiple CT sites.
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Affiliation(s)
- Anaïs Viry
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland.
| | - Veronika Vitzthum
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - Pascal Monnin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - Julie Bize
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
| | - David Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Rue du Bugnon 46, 1011, Lausanne, Switzerland
| | - Damien Racine
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland
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Verfaillie G, Rutten J, D'Asseler Y, Bacher K. Accuracy of patient-specific CT organ doses from Monte Carlo simulations: influence of CT-based voxel models. Phys Eng Sci Med 2024:10.1007/s13246-024-01422-z. [PMID: 38634980 DOI: 10.1007/s13246-024-01422-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/01/2024] [Indexed: 04/19/2024]
Abstract
Monte Carlo simulations using patient CT images as input are the gold standard to perform patient-specific dosimetry. However, in standard clinical practice patient's CT images are limited to the reconstructed CT scan range. In this study, organ dose calculations were performed with ImpactMC for chest and cardiac CT using whole-body and anatomy-specific voxel models to estimate the accuracy of CT organ doses based on the latter model. When the 3D patient model is limited to the CT scan range, CT organ doses from Monte Carlo simulations are the most accurate for organs entirely in the field of view. For these organs only the radiation dose related to scatter from the rest of the body is not incorporated. For organs lying partially outside the field of view organ doses are overestimated by not accounting for the non-irradiated tissue mass. This overestimation depends strongly on the amount of the organ volume located outside the field of view. To get a more accurate estimation of the radiation dose to these organs, the ICRP reference organ masses and densities could form a solution. Except for the breast, good agreement in dose was found for most organs. Voxel models generated from clinical CT examinations do not include the overscan in the z-direction. The availability of whole-body voxel models allowed to study this influence as well. As expected, overscan induces slightly higher organ doses.
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Affiliation(s)
- Gwenny Verfaillie
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium.
| | - Jeff Rutten
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
| | - Yves D'Asseler
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Klaus Bacher
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
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Sá Dos Reis C, De Labouchere S, Campeanu C, Ghotra SS, Flaction L, Marmy L, Vorlet P, Al-Musibli A, Franco L, Champendal M. Alumni, radiographers, clinical placement tutors and industry insights about current radiographers practice, competences and autonomy in western Switzerland. Radiography (Lond) 2024; 30:193-201. [PMID: 38035433 DOI: 10.1016/j.radi.2023.11.007] [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: 08/11/2023] [Revised: 10/02/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023]
Abstract
INTRODUCTION Radiographers' profession is constantly evolving, which demands adaptation of education and training programs to build up medical imaging and radiation therapy professionals (MIRTPs) that provide healthcare to improve patient experience and outcomes. This study aimed to map radiographers' practices, competences, and autonomy level in Western Switzerland. METHODS Data was collected by 2 cross-sectional online surveys targeting Alumni, radiographers, clinical placement tutors and medical imaging equipment specialists from industry, with opened and closed-end questions. Descriptive statistics and thematic analysis were used to analyse the data. RESULTS 81 Alumni and 93 Chief-Radiographers, clinical tutors, practitioner-radiographers and industry answered the questionnaires. The competences considered as the most "acquired or completely acquired" by the Alumni were: adopt a reflective posture on practice (90.1 %; 73/81), adopt ethical behaviour (90.1 %; 73/81), carrying out and providing radiological services for diagnostic, therapeutic and preventive purposes (81.5 %; 68/81), adapting communication to the other surrounding persons (81.5 %; 66/81), and check compliance of procedures with standards (69.1 %; 56/81). Similar results were referred by Employers. The autonomy of the participant radiographers was considered as average, and it focuses only the preparation of the patient and the protocol optimisation. The development and integration of research is weak as well as the application of competences regarding professionalism. CONCLUSIONS A better link between educational institutions and clinical practice can help on the integration of research and evidence-based on practice, necessary to progress the radiographers' profession in Western Switzerland. The autonomy needs to be further developed and leadership courses must be integrated in the curricula to facilitate the implementation of new approaches to reinforce radiographer's profession. IMPLICATIONS FOR PRACTICE Practice must be revised to integrate evidence-based; to facilitate research development, the managers need to increase support.
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Affiliation(s)
- C Sá Dos Reis
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
| | - S De Labouchere
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland; Cantonal University Hospital Vaud (CHUV), Bugnon 46, 1011 Lausanne, Switzerland.
| | - C Campeanu
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
| | - S S Ghotra
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland; Department of Radiology, Hospital of Yverdon-les-Bains (eHnv), 1400 Yverdon-les-Bains, Switzerland.
| | - L Flaction
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
| | - L Marmy
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
| | - P Vorlet
- Cantonal University Hospital Vaud (CHUV), Bugnon 46, 1011 Lausanne, Switzerland.
| | - A Al-Musibli
- Geneva School of Health Sciences (HEdS - Geneva), University of Applied Sciences and Arts Western Switzerland (HES-SO), Genève 1206, Switzerland.
| | - L Franco
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
| | - M Champendal
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1011, Switzerland.
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Sá Dos Reis C, Gulizia M, Champendal M, De Labouchere S, Sun Z, Silva C. Plain radiography has a role to play in current clinical practice in Western Switzerland. J Med Imaging Radiat Sci 2023; 54:670-678. [PMID: 37620178 DOI: 10.1016/j.jmir.2023.08.007] [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: 05/16/2023] [Revised: 07/14/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023]
Abstract
AIM The aim of the study was to investigate the current role of conventional radiography examinations in Western Switzerland and the main clinical indications required to justify the use of this imaging examination. METHODS Ethical approval was obtained from Vaud Ethics committee (Ref 2020-00311). An online questionnaire was specifically designed and implemented on the data collection tool LimeSurvey composed of two parts: a) to characterise the participants' profile and their institutions and b) 169 projections for the different anatomical area (upper and lower limbs, pelvis, skull, spine, thorax, abdomen) were presented to collect data about the frequency and main clinical indications. Statistical analysis was performed using the software IBM SPSS® (Statistical Package for the Social Sciences) version 26. RESULTS Radiographers from 60% (26/43) of the invited institutions participated in this survey, mainly from Vaud region. The upper and lower limbs were the most commonly examined by using conventional radiography mainly for trauma and degenerative disorders. The thorax was also an anatomical area commonly explored by X-rays, so were the spine (cervical and lumbar lateral). The skull radiographs were rarely performed in clinical practice and some of the projections were not being used, namely Hirtz, Tangential Nose Bones, Worms and Caldwell's views. CONCLUSIONS Plain radiography is being used in clinical practice mainly for appendicular skeleton studies and for trauma and degenerative pathologies. Adaptations in radiographers' education and training and other healthcare professionals are needed to provide the judicious use of data that radiographs can give to better manage the patients' imaging pathway.
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Affiliation(s)
- Cláudia Sá Dos Reis
- Department of Radiologic Medical Imaging Technology, School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Switzerland.
| | - Marianna Gulizia
- Cantonal University Hospital Vaud (CHUV), Bugnon 46, 1011 Lausanne, Switzerland.
| | - Mélanie Champendal
- Department of Radiologic Medical Imaging Technology, HESAV School of Health Sciences, University of Applied Sciences and Arts Western Switzerland (HES-SO), Switzerland.
| | - Stephanie De Labouchere
- Cantonal University Hospital Vaud (CHUV), Bugnon 46, 1011 Lausanne, Switzerland; Department of Radiologic Medical Imaging Technology, HESAV School of Health Sciences, University of Applied Sciences and Arts Western Switzerland (HES-SO), Switzerland.
| | - Zhonghua Sun
- Discipline of Medical Radiation Science, Curtin Medical School, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
| | - Carina Silva
- Escola Superior de Tecnologia da Saúde de Lisboa/Instituto Politécnico de Lisboa (ESTeSL/IPL), Lisbon, Portugal; Centro de Estatística e Aplicações da Universidade de Lisboa (CEAUL), Portugal.
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Ståhlbrandt H, Björnfot I, Cederlund T, Almén A. CT and MRI imaging in Sweden: retrospective appropriateness analysis of large referral samples. Insights Imaging 2023; 14:134. [PMID: 37530862 PMCID: PMC10397157 DOI: 10.1186/s13244-023-01483-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/04/2023] [Indexed: 08/03/2023] Open
Abstract
OBJECTIVES The numbers of computed tomography (CT) and magnetic resonance imaging (MRI) examinations per capita continue to increase in Sweden and in other parts of Europe. The appropriateness of CT and MRI examinations was audited using established European appropriateness criteria. Alternative modalities were also explored. The results were compared with those of a previous study performed in Sweden. METHODS A semi-automatic retrospective evaluation of referrals from examinations performed in four healthcare regions using the European appropriateness criteria in ESR iGuide was undertaken. The clinical indications from a total of 13,075 referrals were assessed against these criteria. The ESR iGuide was used to identify alternative modalities resulting in a higher degree of appropriateness. A qualitative comparison with re-evaluated results from the previous study was made. RESULTS The appropriateness was higher for MRI examinations than for CT examinations with procedures classed as usually appropriate for 76% and 63% of the examinations, respectively. The degree of appropriateness for CT was higher for referrals from hospitals compared to those from primary care centres. The opposite was found for MRI examinations. The alternative modalities that would result in higher appropriateness included all main imaging modalities. The result for CT did not show improvement compared with the former study. CONCLUSIONS A high proportion of both CT and MRI examinations were inappropriate. The study indicates that 37% of CT examinations and 24% of MRI examinations were inappropriate and that the appropriateness for CT has not improved in the last 15 years. CRITICAL RELEVANCE STATEMENT A high proportion of CT and MRI examinations in this retrospective study using evidence-based referral guidelines were inappropriate. KEY POINTS ∙ A high proportion of CT and MRI examinations were inappropriate. ∙ The CT referrals from general practitioners were less appropriate that those from hospital specialists. ∙ The MRI referrals from hospital specialists were less appropriate that those from general practitioners. ∙ Adherence to radiological appropriateness guidelines may improve the appropriateness of conducted examinations.
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Affiliation(s)
| | - Ida Björnfot
- Department of Radiology, Länssjukhuset Ryhov, 551 85, Jönköping, Sweden
| | - Torsten Cederlund
- Department for Authorisation of Radiation Applications, Swedish Radiation Safety Authority, 171 16, Stockholm, Sweden
| | - Anja Almén
- Department for Radiation Protection and Environmental Assessment, Swedish Radiation Safety Authority, 171 16, Stockholm, Sweden.
- Medical Radiation Physics, Department of Translational Medicine, Malmö, Lund University, 205 02, Malmö, Sweden.
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Pozzessere C, von Garnier C, Beigelman-Aubry C. Radiation Exposure to Low-Dose Computed Tomography for Lung Cancer Screening: Should We Be Concerned? Tomography 2023; 9:166-177. [PMID: 36828367 PMCID: PMC9964027 DOI: 10.3390/tomography9010015] [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: 11/29/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/26/2023] Open
Abstract
Lung cancer screening (LCS) programs through low-dose Computed Tomography (LDCT) are being implemented in several countries worldwide. Radiation exposure of healthy individuals due to prolonged CT screening rounds and, eventually, the additional examinations required in case of suspicious findings may represent a concern, thus eventually reducing the participation in an LCS program. Therefore, the present review aims to assess the potential radiation risk from LDCT in this setting, providing estimates of cumulative dose and radiation-related risk in LCS in order to improve awareness for an informed and complete attendance to the program. After summarizing the results of the international trials on LCS to introduce the benefits coming from the implementation of a dedicated program, the screening-related and participant-related factors determining the radiation risk will be introduced and their burden assessed. Finally, future directions for a personalized screening program as well as technical improvements to reduce the delivered dose will be presented.
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Affiliation(s)
- Chiara Pozzessere
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland
- Faculty of Biology and Medicine, University of Lausanne (UNIL), 1011 Lausanne, Switzerland
- Correspondence:
| | - Christophe von Garnier
- Faculty of Biology and Medicine, University of Lausanne (UNIL), 1011 Lausanne, Switzerland
- Division of Pulmonology, Department of Medicine, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland
| | - Catherine Beigelman-Aubry
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland
- Faculty of Biology and Medicine, University of Lausanne (UNIL), 1011 Lausanne, Switzerland
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Amalaraj T, Jeyasugiththan J, Satharasinghe D, Pallewatte AS. Dose reference level based on size-specific dose estimate (SSDE) and feasibility of deriving effective body diameter using tube current and time product (mAs) for adult chest and abdomen computed tomography (CT) procedures. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2023; 43:011505. [PMID: 36626827 DOI: 10.1088/1361-6498/acb1bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
This study aimed to establish dose reference level (NDRLSSDE) based on size-specific dose estimate (SSDE) derived using effective diameter (Deff) for adult chest and abdomen computed tomography (CT) procedures and to explore the feasibility of drivingDeffusing the product of tube current and time (mAs). In this retrospective study, dose data, scan parameters and patient body dimensions at the mid-slice level from 14 CT units (out of 63 total) were extracted. Additionally, the mAs values of the axial slice at the samez-location where the diameter measurements were made (mAsz) were recorded. Pearson's correlation (r) analysis was used to determine the relationship ofDeffwith patient BMI, weight, and mAsz. The NDRLSSDEfor the chest and abdomen were 9.72 mGy and 13.4 mGy, respectively. The BMI and body weight were less correlated (r= 0.24 andr= 0.33, respectively) withDeff. The correlation between mAszandDeffwas considerably strong (r= 0.78) and can be used to predictDeffaccurately. The absolute dose differences between SSDEs calculated using the AAPM-204 method and mAszwas less than 1.1 mGy (15%). Therefore, mAszis an efficient parameter to deriveDeff. Further, the direct conversion factors to estimate SSDEs at different locations along thez-direction in the scan region from corresponding mAs and CTDIvolwere calculated. The NDRLSSDEsuggested in the present study can be used as a reference for size-dependent dose optimisation in Sri Lanka, and existing NDRL based on CTDIvolunderestimate the average adult CT dose by 36.0% and 39.7% for chest and abdomen regions respectively. The results show that using mAszto determine SSDE is a simple and practical approach with an accuracy of 95% and 85% for abdomen and chest scans, respectively. However, the obtained linear relationship betweenDeffand mAs is highly dependent on the ATCM technique and the user-determined noise levels of the scanning protocol. Finally, the phantom study resulted in the strongest correlation (r= 0.99) between theDwzand mAsz, and the prediction of patient size would be more precise thanDeffmethod.
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Affiliation(s)
- T Amalaraj
- Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka
| | | | | | - A S Pallewatte
- Department of Radiology, National Hospital of Sri Lanka, Colombo, Sri Lanka
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Shi HM, Sun ZC, Ju FH. Recommendations for reducing exposure to medical X-ray irradiation (Review). MEDICINE INTERNATIONAL 2022; 2:22. [PMID: 36699506 PMCID: PMC9829209 DOI: 10.3892/mi.2022.47] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/08/2022] [Indexed: 02/01/2023]
Abstract
With the increasing frequency of X-ray examinations in clinical medicine, public concern regarding the harm caused by exposure to X-ray radiation is also increasing. However, some physicians are not completely aware of the dangers of exposure to X-ray irradiation. Individuals specialized in this field, including physicians, have a better understanding of these dangers, which limits the use of X-rays in medicine. The present study aimed to address strategies for reducing the harm caused by exposure to medical X-rays and increase public awareness regarding X-ray radiation. Through a literature search and review, combined with the current status of clinical X-ray examination and the authors' professional experience, the present study highlights the importance of reducing X-ray exposure, and proposes several specific recommendations and measures for reducing the frequency or dose of X-ray irradiation. On the whole, the finding discussed in the present review suggest the minimal use of medical X-ray examinations and that alternative tests should be selected whenever possible. When medical X-ray screening and treatments are necessary, the risk-benefit ratio should be assessed, possibly aiming to achieve avoidable exposure. Further attention should be paid to protect sensitive glands and reduce the risks in children.
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Affiliation(s)
- Hai-Min Shi
- Department of Gynecology and Obstetrics Medicine, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China,Department of Gynecology and Obstetrics Medicine, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Zhi-Chao Sun
- Department of Medical Imaging, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China,Department of Medical Imaging, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Fang-He Ju
- Department of Respiratory Medicine, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China,Department of Respiratory Medicine, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang 310006, P.R. China,Correspondence to: Dr Fang-He Ju, Department of Respiratory Medicine, The First Affiliated Hospital of Zhejiang Chinese Medical University, 54 Youdian Road, Hangzhou, Zhejiang 310006, P.R. China
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Shi HM, Sun ZC, Ju FH. Understanding the harm of low‑dose computed tomography radiation to the body (Review). Exp Ther Med 2022; 24:534. [PMID: 35911849 DOI: 10.3892/etm.2022.11461] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/24/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Hai-Min Shi
- Department of Gynecology and Obstetrics Medicine, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Zhi-Chao Sun
- Department of Medical Imaging, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China
| | - Fang-He Ju
- Department of Respiratory Medicine, The First Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang 310006, P.R. China
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Simma L, Fornaro J, Stahr N, Lehner M, Roos JE, Lima TVM. Optimising whole body computed tomography doses for paediatric trauma patients: a Swiss retrospective analysis. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:021521. [PMID: 35354135 DOI: 10.1088/1361-6498/ac6274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
We aimed to evaluate the impact of a low-dose whole-body computed tomography (WBCT) protocol on radiation doses in paediatric major trauma patients. Retrospective cohort study of paediatric trauma patients (<16 years) at a national level 1 paediatric trauma centre (PTC) over a 6 year period prior and post introduction of a low-dose WBCT protocol (2014-2019). Demographic data, patient characteristics, CT device, and exposure information including scan range, dose-length product, and volume CT dose index were collected. Effective dose (ED) and exposure parameters were compared before and after protocol introduction. Forty-eight patients underwent WBCT during the study period. Prior to introduction of the low-dose protocol (n= 18), the ED was 20.6 mSv (median 20.1 ± 5.3 mSv [range 12.5-30.7]). After introduction of the low-dose WBCT protocol (n= 30), mean ED was 4.8 mSv (median 2.6 ± 5.0 [range: 0.8-19.1]). This resulted in a reduction of 77% in mean ED (pvalue <0.001). Significant radiation dose reduction of 77% can be achieved with low-dose WBCT protocols in PTCs.
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Affiliation(s)
- Leopold Simma
- Emergency Department, Children's Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
- Emergency Department, University Children's Hospital Zurich, University of Zurich, Steinwiessstrasse 75, Zurich, CH 8032, Switzerland
| | - Juergen Fornaro
- Institute of Radiology and Nuclear Medicine, Cantonal Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
| | - Nikolai Stahr
- Institute of Radiology and Nuclear Medicine, Cantonal Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
- Pediatric Radiology Department, Children's Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
| | - Markus Lehner
- Pediatric Surgery Department, Children's Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
| | - Justus E Roos
- Institute of Radiology and Nuclear Medicine, Cantonal Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
| | - Thiago Viana Miranda Lima
- Institute of Radiology and Nuclear Medicine, Cantonal Hospital Lucerne, Spitalstrasse, CH-6000 Lucerne, Switzerland
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
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Assessment of task-based image quality for abdominal CT protocols linked with national diagnostic reference levels. Eur Radiol 2021; 32:1227-1237. [PMID: 34327581 PMCID: PMC8794993 DOI: 10.1007/s00330-021-08185-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/04/2021] [Accepted: 06/29/2021] [Indexed: 12/18/2022]
Abstract
Objectives To assess task-based image quality for two abdominal protocols on various CT scanners. To establish a relationship between diagnostic reference levels (DRLs) and task-based image quality. Methods A protocol for the detection of focal liver lesions was used to scan an anthropomorphic abdominal phantom containing 8- and 5-mm low-contrast (20 HU) spheres at five CTDIvol levels (4, 8, 12, 16, and 20 mGy) on 12 CTs. Another phantom with high-contrast calcium targets (200 HU) was scanned at 2, 4, 6, 10, and 15 mGy using a renal stones protocol on the same CTs. To assess the detectability, a channelized Hotelling observer was used for low-contrast targets and a non-prewhitening observer with an eye filter was used for high contrast targets. The area under the ROC curve and signal to noise ratio were used as figures of merit. Results For the detection of 8-mm spheres, the image quality reached a high level (mean AUC over all CTs higher than 0.95) at 11 mGy. For the detection of 5-mm spheres, the AUC never reached a high level of image quality. Variability between CTs was found, especially at low dose levels. For the search of renal stones, the AUC was nearly maximal even for the lowest dose level. Conclusions Comparable task-based image quality cannot be reached at the same dose level on all CT scanners. This variability implies the need for scanner-specific dose optimization. Key Points • There is an image quality variability for subtle low-contrast lesion detection in the clinically used dose range. • Diagnostic reference levels were linked with task-based image quality metrics. • There is a need for specific dose optimization for each CT scanner and clinical protocol.
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