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Bahonar BM, Changizi V, Ebrahiminia A, Baradaran S. Prediction of breast dose in chest CT examinations using adaptive neuro-fuzzy inference system (ANFIS). Phys Eng Sci Med 2023; 46:1071-1080. [PMID: 37245194 PMCID: PMC10225119 DOI: 10.1007/s13246-023-01276-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 05/05/2023] [Indexed: 05/29/2023]
Abstract
In chest computed tomography (CT), the breasts located within the scan range receive a substantial radiation dose. Due to the risk of breast-related carcinogenesis, analyzing the breast dose for justification of CT examinations seems necessary. The main goal of this study is to overcome the limitations of conventional dosimetry methods, such as thermoluminescent dosimeters (TLDs) by introducing the adaptive neuro-fuzzy inference system (ANFIS) approach. In this study, the breast dose of 50 adult female patients who underwent chest CT examinations was measured directly by TLDs. Then, the ANFIS model was developed with four inputs including dose length product (DLP), volumetric CT dose index (CTDIvol), total mAs, and size-specific dose estimate (SSDE), and one output (TLD dose). Additionally, multiple linear regression (MLR) as a traditional prediction model was used for linear modeling and its results were compared with the ANFIS. The TLD reader results showed that the breast dose value was 12.37 ± 2.46 mGy. Performance indices of the ANFIS model, including root mean square error (RMSE) and correlation coefficient (R), were calculated at 0.172 and 0.93 for the testing dataset, respectively. Also, the ANFIS model had superior performance in predicting the breast dose than the MLR model (R = 0.805). This study demonstrates that the proposed ANFIS model is efficient for patient dose prediction in CT scans. Therefore, intelligence models such as ANFIS are suggested to estimate and optimize patient dose in CT examinations.
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Affiliation(s)
- Bahareh Moradmand Bahonar
- Department of Radiology and Radiotherapy Technology, Tehran University of Medical Sciences, Tehran, Iran
| | - Vahid Changizi
- Department of Radiology and Radiotherapy Technology, Tehran University of Medical Sciences, Tehran, Iran.
| | - Ali Ebrahiminia
- Department of Medical Physics, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
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Stogiannos N, Psimitis A, Bougias H, Georgiadou E, Leandrou S, Papavasileiou P, Polycarpou I, Malamateniou C, McEntee MF. Exploring radiographers' perceptions and knowledge about patient lead shielding: a cross-sectional study in Greece and Cyprus. RADIATION PROTECTION DOSIMETRY 2023; 199:1401-1409. [PMID: 37415570 DOI: 10.1093/rpd/ncad194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/02/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023]
Abstract
The present study aimed to explore radiographers' knowledge, clinical practice and perceptions regarding the use of patient lead shielding in Greece and Cyprus. Qualitative data were analyzed using conceptual content analysis and through the classification of findings into themes and categories. A total of 216 valid responses were received. Most respondents reported not being aware of the patient shielding recommendations issued by the American Association of Physicists in Medicine (67%) or the guidance issued by the British Institute of Radiology (69%). Shielding-related training was generally not provided by radiography departments (74%). Most of them (85%) reported that they need specific guidance on lead shielding practices. Also, 82% of the respondents said that lead shielding should continue to be used outside the pelvic area when imaging pregnant patients. Pediatric patients are the most common patient category to which lead shielding was applied. Significant gaps in relevant training have been identified among radiographers in Greece and Cyprus, highlighting the need for new protocols and provision of adequate training on lead shielding practices. Radiography departments should invest in appropriate shielding equipment and adequately train their staff.
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Affiliation(s)
- Nikolaos Stogiannos
- Discipline of Medical Imaging and Radiation Therapy, University College Cork, Cork, T12 R229, Ireland
- Division of Midwifery and Radiography, City University of London, London, EC1V OHB, United Kingdom
- Medical Imaging Department, Corfu General Hospital, Corfu 49100, Greece
| | | | - Haralabos Bougias
- Department of Clinical Radiology, Ioannina University Hospital, Ioannina 45110, Greece
| | | | - Stephanos Leandrou
- School of Science, European University Cyprus, Nicosia 1516, Cyprus
- School of Mathematical Sciences, Computer Science and Engineering, City University of London, London, EC1V 0HB, United Kingdom
| | - Periklis Papavasileiou
- Section of Radiography and Radiotherapy, Department of Biomedical Sciences, School of Health Sciences, University of West Attica, Athens 12243, Greece
| | - Irene Polycarpou
- Department of Health Sciences, European University Cyprus, Nicosia 1516, Cyprus
| | - Christina Malamateniou
- Division of Midwifery and Radiography, City University of London, London, EC1V OHB, United Kingdom
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne 1007, Switzerland
| | - Mark F McEntee
- Discipline of Medical Imaging and Radiation Therapy, University College Cork, Cork, T12 R229, Ireland
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Hurley L, Alashban Y, Albeshan S, England A, McEntee MF. The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study. Diagn Interv Radiol 2023; 29:555-560. [PMID: 37129301 PMCID: PMC10679606 DOI: 10.4274/dir.2023.232126] [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: 01/20/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations. METHODS Using an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student's t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding. RESULTS A total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant. CONCLUSION This study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols.
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Affiliation(s)
- Lauren Hurley
- Department of Medical Imaging and Radiation Therapy, University College Cork, School of Medicine, Brookfield Health Sciences, Munster, Ireland
| | - Yazeed Alashban
- Department of Radiological Sciences, King Saud University, College of Applied Medical Sciences, Riyadh, Saudi Arabia
| | - Salman Albeshan
- Department of Radiological Sciences, King Saud University, College of Applied Medical Sciences, Riyadh, Saudi Arabia
| | - Andrew England
- Department of Medical Imaging and Radiation Therapy, University College Cork, School of Medicine, Brookfield Health Sciences, Munster, Ireland
| | - Mark F. McEntee
- Department of Medical Imaging and Radiation Therapy, University College Cork, School of Medicine, Brookfield Health Sciences, Munster, Ireland
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Kozor R, Abiodun A, Kott K, Manisty C. Non-invasive Imaging in Women With Heart Failure - Diagnosis and Insights Into Disease Mechanisms. Curr Heart Fail Rep 2022; 19:114-125. [PMID: 35507121 PMCID: PMC9177491 DOI: 10.1007/s11897-022-00545-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/22/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE OF REVIEW To summarise the role of different imaging techniques for diagnosis and investigation of heart failure in women. RECENT FINDINGS Although sex differences in heart failure are well recognised, and the scope of imaging techniques is expanding, there are currently no specific guidelines for imaging of heart failure in women. Diagnosis and stratification of heart failure is generally performed first line using transthoracic echocardiography. Understanding the aetiology of heart failure is central to ongoing management, and with non-ischaemic causes more common in women, a multimodality approach is generally required using advanced imaging techniques including cardiovascular magnetic resonance imaging, nuclear imaging techniques, and cardiac computed tomography. There are specific considerations for imaging in women including radiation risks and challenges during pregnancy, highlighting the clear unmet need for cardiology and imaging societies to provide imaging guidelines specifically for women with heart failure.
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Affiliation(s)
- Rebecca Kozor
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
- Royal North Shore Hospital, Sydney, Australia
| | - Aderonke Abiodun
- Institute of Cardiovascular Science, University College London, London, UK
| | | | - Charlotte Manisty
- Institute of Cardiovascular Science, University College London, London, UK
- Barts Heart Centre, St Bartholomew’s Hospital, West Smithfield, London, UK
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Rautiainen J, Juntunen MAK, Kotiaho AO. THE EFFECT OF OUT-OF-PLANE PATIENT SHIELDING ON CT RADIATION EXPOSURE AND TUBE CURRENT MODULATIONS: A PHANTOM STUDY ACROSS THREE VENDORS. RADIATION PROTECTION DOSIMETRY 2022; 198:229-237. [PMID: 35313335 DOI: 10.1093/rpd/ncac032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/10/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
The aim of this study was to evaluate how out-of-plane patient shielding affects radiation exposure parameters and tube current modulation on different vendors' computed tomography (CT) scanners. Helical CT scans were performed using two homogenous phantoms to mimic patient attenuation. Four CT scanners from three vendors were investigated by varying the distance of the patient shield from the border of the imaging volume. Scans were performed with a shield placed before and after the localizer. Changes in volume computed tomography dose index (CTDIvol), dose-length product (DLP) and tube current-time products were studied. Out-of-field lead shield increased the CTDIvol and DLP values for each scanner at least for one scan setting when the shield was present in the localizer. The most notable changes were recorded with >1.3 pitch values when the shield was closest to the scanned volume (2.5 cm), and the scan direction was towards the shield. The usage of patient shields in the localizer CT scans can disturb TCM even when placed 7.5 cm away from the edge of the scan.
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Affiliation(s)
- Jari Rautiainen
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu 90220, Finland
- Department of Radiology, Lapland Central Hospital, Rovaniemi 96101, Finland
| | - Mikael A K Juntunen
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu 90220, Finland
- Research Unit of Medical Imaging, Physics and Technology, Medical Research Center, University of Oulu and Oulu University Hospital, Oulu 90220 Finland
| | - Antti O Kotiaho
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu 90220, Finland
- Terveystalo Healthcare, Helsinki 00100, Finland
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Samara ET, Saltybaeva N, Sans Merce M, Gianolini S, Ith M. Systematic literature review on the benefit of patient protection shielding during medical X-ray imaging: Towards a discontinuation of the current practice. Phys Med 2022; 94:102-109. [PMID: 35030383 DOI: 10.1016/j.ejmp.2021.12.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/15/2021] [Accepted: 12/28/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Patient shielding during medical X-ray imaging has been increasingly criticized in the last years due to growing evidence that it often provides minimal benefit and may even compromise image quality. In Europe, and as also shown in a short assessment in Switzerland, the use of patient shielding is inhomogeneous. The aim of this study was to systematically review recent literature in order to assess benefits and appraise disadvantages related to the routine use of patient shielding. METHODS To evaluate benefits and disadvantages related to the application of patient shielding in radiological procedures, a systematic literature review was performed for CT, radiography, mammography and fluoroscopy-guided medical X-ray imaging. In addition, reports from medical physics societies and authorities of different countries were considered in the evaluation. RESULTS The literature review revealed 479 papers and reports on the topic, from which 87 qualified for closer analysis. The review considered in- and out-of-plane patient shielding as well as shielding for pregnant and pediatric patients. Dose savings and other dose and non-dose related effects of patient shielding were considered in the evaluation. CONCLUSIONS Although patient shielding has been used in radiological practice for many years, its use is no longer undisputed. The evaluation of the systematic literature review of recent studies and reports shows that dose savings are rather minimal while significant dose- and non-dose-related detrimental effects are present. Consequently, the routine usage of patient protection shielding in medical X-ray imaging can be safely discontinued for all modalities and patient groups.
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Affiliation(s)
- Eleni Theano Samara
- Radiation Protection Unit, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Natalia Saltybaeva
- Radiation Protection Unit, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Marta Sans Merce
- Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland
| | | | - Michael Ith
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, University of Bern, Switzerland
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El Merhi F, Bou-Fakhredin R, El Ashkar B, Ghieh D, Ghosn Y, Saade C. State of the art of coronary computed tomography angiography. Radiography (Lond) 2020; 26:174-182. [PMID: 32052781 DOI: 10.1016/j.radi.2019.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/21/2019] [Accepted: 10/02/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVES The aim of this paper is to evaluate contrast media (CM) bolus geometry and opacification patterns in the coronary arteries with particular focus on patient, scanner and safety considerations during coronary computed tomography angiography (CCTA). KEY FINDINGS The rapid evolution of computed tomography (CT) technology has seen this imaging modality challenge conventional coronary angiography in the evaluation of coronary artery disease. Increases in spatial and temporal resolutions have enabled CCTA to become the modality of choice when evaluating the coronary vascular tree as an alternative in the diagnostic algorithm for acute chest pain. However, these new technologic improvements in scanner technology have imposed new challenges for the optimisation of CM delivery and image acquisition strategies. CONCLUSION Understanding basic CM-imaging principles is essential for designing optimal injection protocols according to each specific clinical scenario, independently of scanner technology. IMPLICATIONS FOR PRACTICE With rapid advances in CT scanner technology including faster scan acquisitions, the risk of poor opacification of coronary vasculature increases significantly. Therefore, awareness of CM delivery protocols is paramount to consistently provide optimal image quality at a low radiation dose.
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Affiliation(s)
- F El Merhi
- Diagnostic Radiology Department, American University of Beirut Medical Center, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
| | - R Bou-Fakhredin
- American University of Beirut, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
| | - B El Ashkar
- Diagnostic Radiology Department, American University of Beirut Medical Center, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
| | - D Ghieh
- Diagnostic Radiology Department, American University of Beirut Medical Center, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
| | - Y Ghosn
- Diagnostic Radiology Department, American University of Beirut Medical Center, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
| | - C Saade
- Diagnostic Radiology Department, American University of Beirut Medical Center, P.O. Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon.
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8
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Shafiee M, Rashidfar R, Abdolmohammadi J, Borzoueisileh S, Salehi Z, Dashtian K. A study to assess the knowledge and practice of medical professionals on radiation protection in interventional radiology. Indian J Radiol Imaging 2020; 30:64-69. [PMID: 32476752 PMCID: PMC7240898 DOI: 10.4103/ijri.ijri_333_19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/31/2019] [Accepted: 01/28/2020] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE Ionizing radiation has been extensively used in medical procedures throughout the world. Such interventional radiological procedures could result in occupational exposure that needs urgent control. Therefore, MPs (medical professionals) should receive education and appropriate training on occupational radiation protection. In this context, the present study is aimed to investigate the MPs' knowledge and practice regarding radiation protection principles during interventional radiological procedures. MATERIAL AND METHODS A descriptive questionnaire-based study was carried out among 215 MPs involved in interventional fluoroscopy procedures. The practice of 31 MPs was studied using a checklist based on ALARA principles and ICRP guidelines. RESULTS A total of 43.3% and 45.1% answered correctly for knowledge and practice. However, the difference between radiation protection knowledge and practice between the physicians and nurses was statistically significant. The knowledge and practice survey of MPs demonstrated that nurses rarely adhered to radiation-protection measures. CONCLUSION The present study reflects the lack of knowledge and practice concerning radiation protection concepts among the nurses. This deficiency needs to be resolved by periodic practical radiation protection courses in the curriculum of medicine.
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Affiliation(s)
- Mohsen Shafiee
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasouj, Iran
| | - Razieh Rashidfar
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Jamil Abdolmohammadi
- Department of Radiology, Faculty of Paramedical, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Sajad Borzoueisileh
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasouj, Iran
| | - Zaker Salehi
- Department of Radiation Sciences, School of Paramedical Sciences, Yasuj University of Medical Sciences, Shiraz, Iran
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In vivo radiation dosimetry and image quality of turbo-flash and retrospective dual-source CT coronary angiography. Radiol Med 2019; 125:117-127. [PMID: 31686317 DOI: 10.1007/s11547-019-01103-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/27/2019] [Indexed: 12/18/2022]
Abstract
PURPOSE To compare measured radiation dose (MD), estimated radiation dose (ED) and image quality in coronary computed tomography between turbo-flash (TFP) and retrospective protocol (RP) and correlate MD with size-specific dose estimates (SSDE). MATERIALS AND METHODS In this prospective study, we selected 68 patients (mean age, 59.2 ± 9.7 years) undergoing 192 × 2 dual-source CT (SOMATOM Force, Siemens) to rule out coronary artery disease. Thirty-one underwent TFP and 37 RP. To evaluate in vivo MD, thermoluminescent dosimeters were placed, superficially, at thyroid and heart level, left breast areola and left hemi-thorax. MD in each site, and ED parameters, such as volume CT dose index (CTDIvol), SSDE, dose length product (DLP), effective dose (E), were compared between two protocols with a t test. Image quality was compared between two protocols. Inter-observer agreement was evaluated with a kappa coefficient (k). In each protocol, MD was correlated with SSDE using a Pearson coefficient (r). RESULTS Comparing TFP and RP, MD at thyroid (1.43 vs. 2.58 mGy; p = 0.0408), heart (3.58 vs. 28.72 mGy; p < 0.0001), left breast areola (3.00 vs. 24.21 mGy; p < 0.0001) and left hemi-thorax (2.68 vs. 24.03 mGy; p < 0.0001), CTDIvol, SSDE, DLP and E were significantly lower. Differences in image quality were not statistically significant. Inter-observer agreement was good (k = 0.796) in TFP and very good (k = 0.817) in RP. MD and SSDE excellently correlated with TFP (r = 0.9298, p < 0.0001) and RP (r = 0.9753, p < 0.0001). CONCLUSIONS With TFP, MD, CTDIvol, SSDE, DLP and E were significantly lower, than with RP. Image quality was similar between two protocols. MD correlated excellently with SSDE in each protocol.
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Coronary computed tomographic imaging in women: An expert consensus statement from the Society of Cardiovascular Computed Tomography. J Cardiovasc Comput Tomogr 2018; 12:451-466. [DOI: 10.1016/j.jcct.2018.10.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 10/21/2018] [Indexed: 12/21/2022]
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Tailor TD, Kicska GA, Jacobs JE, Pampaloni MH, Litmanovich DE, Reddy GP. Imaging of Heart Disease in Women. Radiology 2017; 282:34-53. [DOI: 10.1148/radiol.2016151643] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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12
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Abbara S, Blanke P, Maroules CD, Cheezum M, Choi AD, Han BK, Marwan M, Naoum C, Norgaard BL, Rubinshtein R, Schoenhagen P, Villines T, Leipsic J. SCCT guidelines for the performance and acquisition of coronary computed tomographic angiography: A report of the society of Cardiovascular Computed Tomography Guidelines Committee: Endorsed by the North American Society for Cardiovascular Imaging (NASCI). J Cardiovasc Comput Tomogr 2016; 10:435-449. [PMID: 27780758 DOI: 10.1016/j.jcct.2016.10.002] [Citation(s) in RCA: 611] [Impact Index Per Article: 76.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 10/09/2016] [Indexed: 01/20/2023]
Abstract
In response to recent technological advancements in acquisition techniques as well as a growing body of evidence regarding the optimal performance of coronary computed tomography angiography (coronary CTA), the Society of Cardiovascular Computed Tomography Guidelines Committee has produced this update to its previously established 2009 "Guidelines for the Performance of Coronary CTA" (1). The purpose of this document is to provide standards meant to ensure reliable practice methods and quality outcomes based on the best available data in order to improve the diagnostic care of patients. Society of Cardiovascular Computed Tomography Guidelines for the Interpretation is published separately (2). The Society of Cardiovascular Computed Tomography Guidelines Committee ensures compliance with all existing standards for the declaration of conflict of interest by all authors and reviewers for the purpose ofclarity and transparency.
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Affiliation(s)
- Suhny Abbara
- University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Philipp Blanke
- Department of Radiology and Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Michael Cheezum
- Cardiology Service Ft. Belvoir Community Hospital, Ft. Belvoir, VA, United States
| | - Andrew D Choi
- Division of Cardiology and Department of Radiology, The George Washington University School of Medicine, Washington DC, United States
| | - B Kelly Han
- Minneapolis Heart Institute and Children's Heart Clinic, Minneapolis, MN, United States
| | - Mohamed Marwan
- Cardiology Department, University Hospital, Erlangen, Germany
| | - Chris Naoum
- Concord Hospital, The University of Sydney, Sydney, Australia
| | - Bjarne L Norgaard
- Department of Cardiology B, Aarhus University Hospital-Skejby, Aarhus N, Denmark
| | - Ronen Rubinshtein
- Lady Davis Carmel Medical Center & Rappaport School of Medicine- Technion- IIT, Haifa, Israel
| | - Paul Schoenhagen
- Cardiovascular Imaging, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, United States
| | - Todd Villines
- Walter Reed National Military Medical Center, Bethesda, MD, United States
| | - Jonathon Leipsic
- Department of Radiology and Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
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Cheezum MK, Redon CE, Burrell AS, Kaviratne AS, Bindeman J, Maeda D, Balmakhtar H, Pezel A, Wisniewski P, Delacruz P, Nguyen B, Bonner WM, Villines TC. Effects of Breast Shielding during Heart Imaging on DNA Double-Strand-Break Levels: A Prospective Randomized Controlled Trial. Radiology 2016; 281:62-71. [PMID: 27082782 PMCID: PMC5047130 DOI: 10.1148/radiol.2016152301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To examine the effect of breast shielding on blood lymphocyte deoxyribonucleic acid (DNA) double-strand-break levels resulting from in vivo radiation and ex vivo radiation at breast-tissue level, and the effect of breast shielding on image quality. Materials and Methods The study was approved by institutional review and commpliant with HIPAA guidelines. Adult women who underwent 64-section coronary computed tomographic (CT) angiography and who provided informed consent were prospectively randomized to the use (n = 50) or absence (n = 51) of bismuth breast shields. Peripheral blood samples were obtained before and 30 minutes after in vivo radiation during CT angiography to compare DNA double-strand-break levels by γ-H2AX immunofluorescence in blood lymphocytes. To estimate DNA double-strand-break induction at breast-tissue level, a blood sample was taped to the sternum for ex vivo radiation with or without shielding. Data were analyzed by linear regression and independent sample t tests. Results Breast shielding had no effect on DNA double-strand-break levels from ex vivo radiation of blood samples under shields at breast-tissue level (unadjusted regression: β = .08; P = .43 versus no shielding), or in vivo radiation of circulating lymphocytes (β = -.07; P = .50). Predictors of increased DNA double-strand-break levels included total radiation dose, increasing tube potential, and tube current (P < .05). With current radiation exposures (median, 3.4 mSv), breast shielding yielded a 33% increase in image noise and 19% decrease in the rate of excellent quality ratings. Conclusion Among women who underwent coronary CT angiography, breast shielding had no effect on DNA double-strand-break levels in blood lymphocytes exposed to in vivo radiation, or ex vivo radiation at breast-tissue level. At present relatively low radiation exposures, breast shielding contributed to an increase in image noise and a decline in image quality. The findings support efforts to minimize radiation by primarily optimizing CT settings. (©) RSNA, 2016 Clinical trial registration no. NCT02617888 Online supplemental material is available for this article.
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Affiliation(s)
- Michael K. Cheezum
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Christophe E. Redon
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Allison S. Burrell
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Anthony S. Kaviratne
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Jody Bindeman
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Daisuke Maeda
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Houria Balmakhtar
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Ashly Pezel
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Piotr Wisniewski
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Panfilo Delacruz
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Binh Nguyen
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - William M. Bonner
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
| | - Todd C. Villines
- From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.)
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Vadvala H, Engel LC, Ghoshhajra BB. Letter to the Editor Regarding “Ruling Out Coronary Artery Disease in Women with Atypical Chest Pain: Results of Calcium Score Combined with Coronary Computed Tomography Angiography, and Associated Radiation Exposure”. J Womens Health (Larchmt) 2015; 24:1050. [DOI: 10.1089/jwh.2015.5524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Harshna Vadvala
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Leif-Christopher Engel
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brian B. Ghoshhajra
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Organ Doses and Radiation Risk of Computed Tomographic Coronary Angiography in a Clinical Patient Population: How Do Low-Dose Acquisition Modes Compare? J Comput Assist Tomogr 2015; 39:591-7. [PMID: 26182227 DOI: 10.1097/rct.0000000000000253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To compare the organ doses and lifetime-attributable risk of cancer for electrocardiogram-triggered sequential and high-pitch helical scanning in a clinical patient population. METHODS Phantom thermoluminiscence dosimeter measurements were used as a model for the organ dose assessment of 314 individual patients who underwent coronary computed tomographic angiography. Patient-specific lifetime-attributable cancer risks were calculated. RESULTS Phantom measurements showed that heart rate had a significant influence on the delivered radiation exposure in sequential mode, and calcium scoring and contrast bolus tracking scans make a nonnegligible contribution to patients' dose. Therefore, they should be taken into account for patients' organ dose estimations. Median cancer induction risks are low, with 0.008% (0.0016%) and 0.022% (0.056%) for high-pitch and sequential scanning for men (women), respectively. CONCLUSIONS The use of high-pitch helical scanning leads to 65% and 72% lower lifetime-attributable risk values for men and women, respectively, compared with sequential scanning.
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Litmanovich DE, Tack DM, Shahrzad M, Bankier AA. Dose reduction in cardiothoracic CT: review of currently available methods. Radiographics 2015; 34:1469-89. [PMID: 25310412 DOI: 10.1148/rg.346140084] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Radiation exposure from computed tomography (CT) has received much attention lately in the medical literature and the media, given the relatively high radiation dose that characterizes a CT examination. Although there are a variety of possible strategies for reducing radiation exposure from CT in an individual patient, optimal CT image acquisition requires that the radiologist understand new scanner technology and how to implement the most effective means of dose reduction while maintaining image quality. The authors describe a practical approach to dose reduction in cardiothoracic radiology, discussing CT radiation dose metrics (eg, CT dose index, dose-length product, effective diameter, and size-specific dose estimate) as well as CT scanner parameters that directly or indirectly influence radiation dose (eg, scan length, x-ray tube output, tube current modulation, pitch, image reconstruction techniques [including iterative reconstruction], and noise reduction). These variables are discussed in terms of their relative importance to image quality and the implications of parametric changes for image quality and diagnostic content, and practical recommendations are made for their immediate implementation in the clinical setting. Taken together, the principles of physics and key parameters involved in reducing radiation dose while maintaining image quality can serve as a "survival guide" for a diagnostic radiology practice.
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Affiliation(s)
- Diana E Litmanovich
- From the Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Shapiro 4, Boston, MA 02215 (D.E.L., M.S., A.A.B.); and Department of Radiology, Epicura Hospital, Baudour, Belgium (D.M.T.)
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Zarb F, McEntee MF, Rainford L. Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations. Insights Imaging 2015; 6:393-401. [PMID: 25510470 PMCID: PMC4444791 DOI: 10.1007/s13244-014-0374-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 11/16/2014] [Accepted: 11/21/2014] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. METHODS Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis. RESULTS VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases. CONCLUSIONS The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings. MAIN MESSAGES • There is need for scientifically based image quality evaluation during CT optimisation. • VGC and ordinal regression analysis in combination led to better informed clinical decisions. • VGC and ordinal regression analysis led to dose reductions without compromising diagnostic efficacy.
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Affiliation(s)
- Francis Zarb
- Department of Radiography, Faculty of Health Sciences, University of Malta, Msida, Malta
| | - Mark F. McEntee
- Discipline of Medical Radiation Sciences and Brain and Mind Research Institute, Faculty of Health Sciences, The University of Sydney, Sydney, Australia
| | - Louise Rainford
- School of Medicine & Medical Science, Health Science Centre, University College Dublin, Belfield, Dublin 4, Ireland
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Abstract
OBJECTIVE The objective of this study was to assess the potential of anterior in beam bismuth shields placed on the abdomen and the pelvis of a RANDO phantom to decrease radiation dose to a simulated fetus. METHODS Thermal luminescent dosimeters irradiated in a RANDO phantom were used to measure radiation dose at 0 weeks and 18 weeks after conception. An 18-week gestation was simulated by adding the corresponding equivalent of super-stuff to account for additional subcutaneous tissue. To assess image quality, a 461A body phantom with low contrast resolution phantom insert was used. The minimum size of low contrast resolution target visualize was recorded with no shielding and 25-cm-wide shielding. RESULTS With shields, there was a radiation dose reduction of 19% to 23% at 0-week gestation and 16% to 24% at 18-week gestation. No qualitative difference was found in low contrast detectability with the shields. CONCLUSIONS These shields reduce fetal radiation exposure early in pregnancy with acceptable image quality.
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Vadvala H, Kim P, Mayrhofer T, Pianykh O, Kalra M, Hoffmann U, Ghoshhajra B. Coronary CTA using scout-based automated tube potential and current selection algorithm, with breast displacement results in lower radiation exposure in females compared to males. Cardiovasc Diagn Ther 2015; 4:470-9. [PMID: 25610804 DOI: 10.3978/j.issn.2223-3652.2014.12.07] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 12/12/2014] [Indexed: 11/14/2022]
Abstract
PURPOSE To evaluate the effect of automatic tube potential selection and automatic exposure control combined with female breast displacement during coronary computed tomography angiography (CCTA) on radiation exposure in women versus men of the same body size. MATERIALS AND METHODS Consecutive clinical exams between January 2012 and July 2013 at an academic medical center were retrospectively analyzed. All examinations were performed using ECG-gating, automated tube potential, and tube current selection algorithm (APS-AEC) with breast displacement in females. Cohorts were stratified by sex and standard World Health Organization body mass index (BMI) ranges. CT dose index volume (CTDIvol), dose length product (DLP) median effective dose (ED), and size specific dose estimate (SSDE) were recorded. Univariable and multivariable regression analyses were performed to evaluate the effect of gender on radiation exposure per BMI. RESULTS A total of 726 exams were included, 343 (47%) were females; mean BMI was similar by gender (28.6±6.9 kg/m(2) females vs. 29.2±6.3 kg/m(2) males; P=0.168). Median ED was 2.3 mSv (1.4-5.2) for females and 3.6 (2.5-5.9) for males (P<0.001). Females were exposed to less radiation by a difference in median ED of -1.3 mSv, CTDIvol -4.1 mGy, and SSDE -6.8 mGy (all P<0.001). After adjusting for BMI, patient characteristics, and gating mode, females exposure was lower by a median ED of -0.7 mSv, CTDIvol -2.3 mGy, and SSDE -3.15 mGy, respectively (all P<0.01). CONCLUSIONS We observed a difference in radiation exposure to patients undergoing CCTA with the combined use of AEC-APS and breast displacement in female patients as compared to their BMI-matched male counterparts, with female patients receiving one third less exposure.
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Affiliation(s)
- Harshna Vadvala
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Phillip Kim
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Thomas Mayrhofer
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Oleg Pianykh
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Mannudeep Kalra
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Udo Hoffmann
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Brian Ghoshhajra
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Low Radiation Coronary CT. CURRENT CARDIOVASCULAR IMAGING REPORTS 2014. [DOI: 10.1007/s12410-014-9284-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
OBJECTIVE Organ-based tube current modulation has been shown to significantly reduce the radiation dose to the female breast in phantom studies. We sought to assess the proportions of female breast and glandular tissues that are within the range of organ-based tube current modulation in different age groups and whether these proportions could be optimized by clothing. The secondary objective of our study was to determine whether metal parts of brassieres cause artifacts that impair the diagnostic value. SUBJECTS AND METHODS Five hundred seventy-eight female patients undergoing chest CT were included in this study. Two hundred nine patients were prospectively examined wearing a brassiere (group A), and the control patients (group B; n = 369) were scanned according to our previous standard without wearing a brassiere during CT. The two groups were subdivided according to cup size (A-E). For CT data acquisition, an angle-dependent tube current modulation, which reduces the tube current for anterior tube position to minimize direct exposure to anteriorly located organs, was used. The proportion of breast tissue and glandular tissue located within and outside the region of tube current reduction was assessed. RESULTS The results showed that 60.4% of total breast tissue and 67.1% of glandular tissue was inside the region of tube current reduction in group B; the proportions were significantly improved, to an average of 91.3% and 96%, respectively, in group A. Diagnostically relevant artifacts were introduced in none of the patients. Patients' age correlated with this effect, with higher rates of improvement in the older patient group. Angle-dependent tube current modulation was most effective in patients with cup size A while wearing a brassiere. In this group, 97.5% of breast tissue and 98.1% of glandular tissue was inside the region of tube current reduction. Women with a cup size of E had the largest effect of wearing a brassiere, increasing the rate of breast tissue that was affected by angle-dependent tube current modulation from 30.0% to 83.3% and that of glandular tissue from 31.8% to 90.0%. CONCLUSION We show that wearing a brassiere increases the percentage of breast tissue within the region of reduced tube current and, therefore, improves the performance of angle-dependent tube current modulation technique.
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Hoppe ME, Gandhi D, Stevens GM, Foley WD, Schmidt TG. The effects of gantry tilt on breast dose and image noise in cardiac CT. Med Phys 2013; 40:121905. [PMID: 24320516 DOI: 10.1118/1.4829521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans. METHODS Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0°-30°, in 5° increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images. RESULTS Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30° gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%-30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%-50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles. CONCLUSIONS Tilting the gantry reduced the dose to the breast, while also increasing noise standard deviation. Overall, the noise increase outweighed the dose reduction for the eight voxelized phantoms, suggesting that tilted gantry acquisition may not be beneficial for reducing breast dose while maintaining image quality.
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Affiliation(s)
- Michael E Hoppe
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233
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Joyce M, McEntee M, Brennan PC, O’Leary D. Reducing Dose for Digital Cranial Radiography: The Increased Source to the Image-receptor Distance Approach. J Med Imaging Radiat Sci 2013; 44:180-187. [DOI: 10.1016/j.jmir.2013.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 11/16/2022]
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Reduced radiation exposure of the female breast during low-dose chest CT using organ-based tube current modulation and a bismuth shield: comparison of image quality and radiation dose. AJR Am J Roentgenol 2013; 200:537-44. [PMID: 23436842 DOI: 10.2214/ajr.12.9237] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to evaluate the effect of organ-based tube current modulation and bismuth shielding on image quality and breast radiation dose in women undergoing low-dose chest CT. SUBJECTS AND METHODS From March 2011 through July 2011, 80 women prospectively underwent low-dose chest CT to screen for lung cancer. The patients were randomly assigned to a control group (n = 20), organ-based tube current modulation group (n = 20), breast shield group (n = 20), or breast shield plus organ-based tube current modulation group (n = 20). Axial slice images of the aortic arch, carina, and inferior pulmonary vein were used to analyze image quality. Three radiologists scored the image quality in terms of artifact and noise and then characterized the overall image quality as optimal (does not affect the diagnostic accuracy) or suboptimal (affects the diagnostic accuracy). Noise levels were measured in the anterior and posterior lung in each image. A phantom dose study was conducted to measure radiation dose. RESULTS Images with artifacts or noise were more frequently obtained in the breast shield groups; however, the overall image quality was not significantly different among the four groups. Measured noise levels in the anterior lung were significantly higher in the breast shield groups than the control group; however, no statistical significance was found among the four groups with regard to noise level in the posterior lung. In the phantom dose study, a 16-37.5% dose reduction in the breast was achieved using the breast shield, organ-based tube current modulation protocol, or both. CONCLUSION The radiation dose in the female breast may be reduced using a breast shield or organ-based tube current modulation during low-dose chest CT with acceptable image quality. The use of organ-based tube current modulation reduced the radiation dose in the breast without inducing image quality deterioration.
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The effect of breast shielding during lumbar spine radiography. Radiol Oncol 2013; 47:26-31. [PMID: 23450158 PMCID: PMC3573831 DOI: 10.2478/raon-2013-0004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 09/18/2012] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The aim of the study was to determine the influence of lead shielding on the dose to female breasts in conventional x-ray lumbar spine imaging. The correlation between the body mass index and the dose received by the breast was also investigated. MATERIALS AND METHODS Breast surface dose was measured by thermoluminescent dosimeters (TLD). In the first phase measurements of breast dose with and without shielding from lumbar spine imaging in two projections were conducted on an anthropomorphic phantom. In the second stage measurements were performed on 100 female patients, randomly divided into two groups of 50, with breast shielding only used in one group. RESULTS On average, breast exposure dose in lumbar spine imaging in both projections (anteroposterior (AP) and lateral) was found reduced by approximately 80% (p < 0,001) when shielding with 0.5 mm lead equivalent was used (from 0.45±0.25 mGy to 0.09±0.07 mGy on the right and from 0.26±0.14 mGy to 0.06±0.04 mGy on the left breast). No correlation between the body mass index (BMI) and the breast surface radiation dose was observed. CONCLUSIONS Although during the lumbar spine imaging breasts receive low-dose exposure even when shielding is not used, the dose can be reduced up to 80% by breast shielding with no influence on the image quality.
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