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Massera RT, Dehairs M, Verhoeven H, Bosmans H, Marshall N. A comprehensive assessment of a prototype high ratio antiscatter grid in interventional cardiology using experimental measurements and Monte Carlo simulations. Phys Med Biol 2024; 69:135015. [PMID: 38862002 DOI: 10.1088/1361-6560/ad56f3] [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: 11/20/2023] [Accepted: 06/11/2024] [Indexed: 06/13/2024]
Abstract
Objective. To assess the performance of a new antiscatter grid design in interventional cardiology for image quality improvement and dose reduction using experimental measurements and Monte Carlo (MC) simulation.Approach.Experimental measurements were performed on an angiography system, using a multi-layered tissue simulating composite phantom made from of poly(methyl methacrylate), aluminium and expanded polystyrene (2/0.2/0.7 cm). The total phantom thickness ranged from 20.3 cm to 40.6 cm. Four conditions were compared; (A) 105 cm source-image receptor distance (SID) without grid, (Bi) 105 cm SID with grid ratio (r) and strip density (N) (r15N80), (Bii) 120 cm SID without grid, and (Biii) 120 cm SID with high ratio grid (r29N80). The system efficiency (η), defined by the signal-to-noise ratio, was compared from theBconditions against caseA. These conditions were also simulated with MC techniques, allowing additional phantom compositions to be explored. Weighted image quality improvement factor (ηw(u)) was studied experimentally at a specific spatial frequency due to the SID change. Images were simulated with an anthropomorphic chest phantom for the different conditions, and the system efficiency was compared for the different anatomical regions.Main results.Good agreement was found between theηandηw(u) methods using both measured and simulated data, with average relative differences between 2%-11%. CaseBiiiprovided higherηvalues compared toA, andBifor thicknesses larger than 20.3 cm. In addition, caseBiiialso provided higherηvalues for high attenuating areas in the anthropomorphic phantom, such as behind the spine.Significance.The new antiscatter grid design provided higher system efficiency compared to the standard grid for the parameters explored in this work.
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Affiliation(s)
- Rodrigo T Massera
- Medical Imaging Research Centre, Medical Physics and Quality Assessment, KU Leuven, 3000 Leuven, Belgium
| | - Michiel Dehairs
- Medical Imaging Research Centre, Medical Physics and Quality Assessment, KU Leuven, 3000 Leuven, Belgium
- Department of Medical Physics, Institute Jules Bordet Instituut, Rue Meylemeersch 90, Bruxelles 1070, Belgium
| | - Hannelore Verhoeven
- Competentiecentrum medische stralingsfysica, UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
| | - Hilde Bosmans
- Medical Imaging Research Centre, Medical Physics and Quality Assessment, KU Leuven, 3000 Leuven, Belgium
- Competentiecentrum medische stralingsfysica, UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
| | - Nicholas Marshall
- Medical Imaging Research Centre, Medical Physics and Quality Assessment, KU Leuven, 3000 Leuven, Belgium
- Competentiecentrum medische stralingsfysica, UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
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Supanich M, Siewerdsen J, Fahrig R, Farahani K, Gang GJ, Helm P, Jans J, Jones K, Koenig T, Kuhls-Gilcrist A, Lin M, Riddell C, Ritschl L, Schafer S, Schueler B, Silver M, Timmer J, Trousset Y, Zhang J. AAPM Task Group Report 238: 3D C-arms with volumetric imaging capability. Med Phys 2023; 50:e904-e945. [PMID: 36710257 DOI: 10.1002/mp.16245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 12/21/2022] [Accepted: 01/09/2023] [Indexed: 01/31/2023] Open
Abstract
This report reviews the image acquisition and reconstruction characteristics of C-arm Cone Beam Computed Tomography (C-arm CBCT) systems and provides guidance on quality control of C-arm systems with this volumetric imaging capability. The concepts of 3D image reconstruction, geometric calibration, image quality, and dosimetry covered in this report are also pertinent to CBCT for Image-Guided Radiation Therapy (IGRT). However, IGRT systems introduce a number of additional considerations, such as geometric alignment of the imaging at treatment isocenter, which are beyond the scope of the charge to the task group and the report. Section 1 provides an introduction to C-arm CBCT systems and reviews a variety of clinical applications. Section 2 briefly presents nomenclature specific or unique to these systems. A short review of C-arm fluoroscopy quality control (QC) in relation to 3D C-arm imaging is given in Section 3. Section 4 discusses system calibration, including geometric calibration and uniformity calibration. A review of the unique approaches and challenges to 3D reconstruction of data sets acquired by C-arm CBCT systems is give in Section 5. Sections 6 and 7 go in greater depth to address the performance assessment of C-arm CBCT units. First, Section 6 describes testing approaches and phantoms that may be used to evaluate image quality (spatial resolution and image noise and artifacts) and identifies several factors that affect image quality. Section 7 describes both free-in-air and in-phantom approaches to evaluating radiation dose indices. The methodologies described for assessing image quality and radiation dose may be used for annual constancy assessment and comparisons among different systems to help medical physicists determine when a system is not operating as expected. Baseline measurements taken either at installation or after a full preventative maintenance service call can also provide valuable data to help determine whether the performance of the system is acceptable. Collecting image quality and radiation dose data on existing phantoms used for CT image quality and radiation dose assessment, or on newly developed phantoms, will inform the development of performance criteria and standards. Phantom images are also useful for identifying and evaluating artifacts. In particular, comparing baseline data with those from current phantom images can reveal the need for system calibration before image artifacts are detected in clinical practice. Examples of artifacts are provided in Sections 4, 5, and 6.
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Affiliation(s)
- Mark Supanich
- Rush University Medical Center, Chicago, Illinois, USA
| | | | | | | | | | - Pat Helm
- Medtronic Inc., Minneapolis, Minnesota, USA
| | | | - Kyle Jones
- University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | | | - MingDe Lin
- Yale University, New Haven, Connecticut, USA
| | | | | | | | | | - Mike Silver
- Canon Medical Systems USA, Long Beach, California, USA
| | | | | | - Jie Zhang
- University of Kentucky, Lexington, Kentucky
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3
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Ingleby HR, Bonilha HS, Steele CM. A Tutorial on Diagnostic Benefit and Radiation Risk in Videofluoroscopic Swallowing Studies. Dysphagia 2023; 38:517-542. [PMID: 34254167 DOI: 10.1007/s00455-021-10335-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/23/2021] [Indexed: 10/20/2022]
Abstract
The videofluoroscopic swallowing study (VFSS) is a key tool in assessing swallowing function. As with any diagnostic procedure, the probable benefits of the study must be weighed against possible risks. The probable benefit of VFSS is an accurate assessment of swallowing function, enabling patient management decisions potentially leading to improved patient health status and quality of life. A possible (though highly unlikely) risk in VFSS is carcinogenesis, arising from the use of ionizing radiation. Clinicians performing videofluoroscopic swallowing studies should be familiar with both sides of the risk benefit equation in order to determine whether the study is medically justified. The intent of this article is to provide the necessary background for conversations about benefit and risk in videofluoroscopic swallowing studies.
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Affiliation(s)
- Harry R Ingleby
- Division of Medical Physics, CancerCare Manitoba; Departments of Radiology and Physics & Astronomy, University of Manitoba, 675 McDermot Avenue, Winnipeg, MB, R3E 0V9, Canada.
| | - Heather S Bonilha
- Departments of Rehabilitation Sciences; Health Science and Research; and Otolaryngology - Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Catriona M Steele
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network, Toronto, ON, Canada
- Rehabilitation Sciences Institute, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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4
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Local reference and achievable dose levels for vascular and enterostomy access procedures in pediatric interventional radiology. Pediatr Radiol 2023; 53:942-952. [PMID: 36595081 DOI: 10.1007/s00247-022-05562-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/30/2022] [Accepted: 12/01/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND Knowledge of radiation quantities delivered in routine practice is an essential responsibility of a pediatric interventional radiology department. OBJECTIVE To review radiation indices in frequently performed vascular and enterostomy access procedures at a quaternary pediatric hospital to formulate dosimetric reference levels and achievable levels. MATERIALS AND METHODS A retrospective review of patient demographics, procedure information and quantitative dose metrics over a 2-year period was performed. Dosimetric details for common procedures (central line insertions, gastrostomy/gastrojejunostomy insertions and maintenance) were evaluated, correlated with demographic data and stratified across five weight groups (0-5 kg, 5-15 kg, 15-30 kg, 30-50 kg, 50-80 kg). Achievable (50th percentile) and reference (75th percentile) levels with confidence intervals were established for each procedure. RESULTS Within the evaluation period, 3,165 studies satisfied the inclusion criteria. Five were classified as device insertions (peripherally inserted central catheter, n=1,145; port-a-catheter, n=321; central venous line, n=285; gastrostomy-tube [G-tube], n=262, and gastrojejunostomy-tube [GJ-tube], n=66), and two were classified as maintenance procedures (G-tube, n=358, and GJ-tube, n=728, checks, exchanges and reinsertions). Representative reference and achievable levels were calculated for each procedure category and weight group. CONCLUSION This work highlights the creation of local reference and achievable levels for common pediatric interventional procedures. These data establish a dosimetric reference to understand the quantity of radiation routinely applied, allowing for improved relative radiation risk assessment and enriched communication to interventionalists, health care providers, parents and patients.
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Fisher RF, Applegate KE, Berkowitz LK, Christianson O, Dave JK, DeWeese L, Harris N, Jafari ME, Jones AK, Kobistek RJ, Loughran B, Marous L, Miller DL, Schueler B, Schwarz BC, Springer A, Wunderle KA. AAPM Medical Physics Practice Guideline 12.a: Fluoroscopy dose management. J Appl Clin Med Phys 2022; 23:e13526. [PMID: 35174964 PMCID: PMC8906204 DOI: 10.1002/acm2.13526] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022] Open
Affiliation(s)
- Ryan F Fisher
- Department of Radiology, The Metro Health System, Cleveland, Ohio, USA
| | - Kimberly E Applegate
- Department of Radiology, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | | | - Olav Christianson
- Clinical Dose Optimization Service, LANDAUER Medical Physics, Glenwood, Illinois, USA
| | - Jaydev K Dave
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Lindsay DeWeese
- Department of Diagnostic Radiology, Oregon Health & Science University, Portland, Oregon, USA
| | - Nichole Harris
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Mary Ellen Jafari
- Department of Radiation Physics & Safety, Atlantic Medical System Morristown, Morristown, New Jersey, USA
| | - A Kyle Jones
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Brendan Loughran
- Clinical Dose Optimization Service™/OPTIMIZE™ Division, LANDAUER Medical Physics, Glenwood, Illinois, USA
| | - Loren Marous
- Upstate Medical Physics, P.C., Victor, New York, USA
| | - Donald L Miller
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Beth Schueler
- Mayo Clinic, Department of Radiology, Rochester, Minnesota, USA
| | - Bryan C Schwarz
- Department of Radiology, University of Florida, Gainesville, Florida, USA
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Kidoń J, Polaczek-Grelik K, Żurek P, Wojakowski W, Ochala A. Exposure of the eye lens and brain for interventional cardiology staff. ADVANCES IN INTERVENTIONAL CARDIOLOGY 2021; 17:298-304. [PMID: 34819966 PMCID: PMC8596714 DOI: 10.5114/aic.2021.109576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/12/2021] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Occupational exposure to ionizing radiation for people working with an X-ray treatment unit is one of the highest in medicine. The epidemiological data analyzed by the International Commission on Radiological Protection (ICRP) indicate that the dose threshold for tissues located in the eye lens is or may be lower than previously thought. The new ICRP recommendations reduce the currently used threshold 7.5 times to the limit of 20 mSv per year. AIM To carry out measurements of equivalent doses for the lenses and scalps of cardiology interventional staff to determine the actual exposure. MATERIAL AND METHODS Personnel performing interventional cardiology procedures participated in the measurements. The measurements were performed using thermoluminescence dosimetry in two measurement periods. The operational quantities used in individual dosimetry were determined (dose equivalent for the scalp, dose equivalent for the eye lens). In both measurement periods, 69 operators and 12 nurses took part. RESULTS The maximum value of eye doses for cardiologists was 18.80 mSv per year, with a mean of 9.83 ±6.47 mSv/year (for all cases), 5.70 ±4.26 mSv/year (with safety glasses/headgear), 13.14 ±6.28 mSv/year (without safety glasses/headgear), and 6.28 ±1.76 mSv per year for the nurses. The values of brain doses fluctuate around 1 mSv per quarter. CONCLUSIONS Dose equivalents for the lenses of the eyes obtained by cardiologists may be close to or exceed the current dose limits.
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Affiliation(s)
- Joanna Kidoń
- Invasive Cardiology and Electrocardiology Department, Medical University of Silesia, Katowice, Poland
| | - Kinga Polaczek-Grelik
- Prof. K. Gibiński Memorial University Clinical Centre, Medical University of Silesia, Katowice, Poland
| | - Przemysław Żurek
- 2 Department of Cardiology, Upper Silesian Medical Center, Katowice, Poland
| | - Wojciech Wojakowski
- 3 Department of Cardiology, School of Medicine, Medical University of Silesia, Katowice, Poland
| | - Andrzej Ochala
- Invasive Cardiology and Electrocardiology Department, Medical University of Silesia, Katowice, Poland
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Dehairs M, Bosmans H, Leghissa M, Marshall NW. X-ray image quality and system exposure parameters for a hybrid Angio-MR system. Phys Med Biol 2020; 65:245025. [PMID: 32512547 DOI: 10.1088/1361-6560/ab9a83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study investigates the exposure parameters and required x-ray tube output when performing neurological procedures on a hybrid Angio-MR concept system proposed by Siemens Healthineers. The x-ray part of this system uses a longer source to detector distance than conventional (C-arm) systems and will have a fixed amount of filtration. Additionally, as the x-ray source is situated inside a magnetic field, the focal spot size and shape may be slightly distorted. In order to compare the Angio-MR system to a typical C-arm system, the exposure parameters of 60 thrombectomy procedures, performed in our hospital over the course of one year, were investigated in detail and a set of median values was determined. An analytical simulation platform was then developed to calculate the required tube voltage, tube current and pulse length to reach similar spatial frequency dependent signal difference to noise ratio (SDNR(u)) values as a conventional C-arm angiography system. These simulations were performed for a variety of focal spot sizes for the Angio-MR system. Results show that a standard current x-ray tube has sufficient power to reach similar SDNR(u) values as obtained in a conventional system if the focal spot size between both systems is comparable.
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Affiliation(s)
- M Dehairs
- UZ Gasthuisberg, Department of Radiology, Herestraat 49, 3000, Leuven, Belgium. Author to whom any correspondence should be addressed
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8
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High-Dose Fluoroscopically Guided Procedures in Patients: Radiation Management Recommendations for Interventionalists. Cardiovasc Intervent Radiol 2020; 44:849-856. [PMID: 33184693 DOI: 10.1007/s00270-020-02703-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/31/2020] [Indexed: 12/19/2022]
Abstract
The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. In addition to the risks from fluoroscopic-guided interventional procedures of tissue injuries, recent studies have drawn attention to the risk of stochastic effects. Guidelines exist for preprocedural planning and radiation management during the procedure. The concept of a substantial radiation dose level (SRDL) is helpful for patient follow-up for tissue injury. The uncommon nature of tissue injuries requires the interventionalist to be responsible for follow-up of patients who receive substantial radiation doses. Dose management systems for recognizing and avoiding higher patient exposures have been introduced. The European Directive provides a legal framework and requirements for equipment, training, dose monitoring, recording and optimization that are helpful in radiation risk management.
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Worrall M, Shaw D, Baker C, Charnock P, Fazakerley J, Honey I, Iball G, Koutalonis M, Price M, Renaud C, Rose A, Wood T. IPEM Topical Report: an evidence and risk assessment based analysis of the efficacy of quality assurance tests on fluoroscopy units-part I; dosimetry and safety. Phys Med Biol 2019; 64:195011. [PMID: 31422951 DOI: 10.1088/1361-6560/ab3bd7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This work aims to assess the efficacy of x-ray quality assurance tests undertaken on fluoroscopy units in the UK. Information was gathered on the results of dosimetry and safety tests recommended by the reports of the Institute of Physics and Engineering in Medicine, and those additionally undertaken by medical physics departments. The assessment of efficacy considers the frequency with which a test result breaches the remedial level or other relevant threshold where applicable. The third quartile of those results exceeding the remedial level or threshold is used to estimate the severity of such a breach in terms of potential impact on patient dose and image quality. A risk assessment approach is then used to recommend to what degree, if any, the test should be included in an on-going test regimen. Data was analysed from 468 testing sessions to 336 unique fluoroscopy units throughout the UK. Across all tests, the rate with which the remedial level was exceeded varied from 0%-29.5%, with severity ranging from little or none to major degradation to image quality or significant increase on population dose. Where possible, the data has also been used to produce representative ranges for the results of dosimetric tests. These could be useful as an up to date comparator for those sites considering the purchase of or commissioning new equipment. Overall the results indicate a wide range for the efficacy of those tests undertaken at present; this can be used to review local test protocols and to inform future changes to national guidance in the UK. The results also highlight some tests where measurement technique varies significantly throughout the UK, making any valid comparison difficult. This may indicate a need for further guidance on how best to undertake these tests.
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Affiliation(s)
- Mark Worrall
- NHS Tayside, Dundee, United Kingdom. Author to whom corrrespondence should be addressed
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Jones AK, Yevich S. Imaging Techniques to Aid IR Treatment of Musculoskeletal Malignancy. Semin Intervent Radiol 2019; 36:49-62. [PMID: 30936620 DOI: 10.1055/s-0039-1679952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- A Kyle Jones
- Division of Diagnostic Imaging, Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Steven Yevich
- Division of Diagnostic Imaging, Department of Interventional Radiology, The University of Texas, MD Anderson Cancer Center, Houston, Texas
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Dehairs M, Bosmans H, Marshall NW. Implementation of a spatio-temporal figure of merit for new automatic dose rate control regimes in dynamic x-ray imaging. ACTA ACUST UNITED AC 2019; 64:045001. [DOI: 10.1088/1361-6560/aafd5c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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de Ruiter QMB, Reitsma JB, Moll FL, van Herwaarden JA. Meta-analysis of Cumulative Radiation Duration and Dose During EVAR Using Mobile, Fixed, or Fixed/3D Fusion C-Arms. J Endovasc Ther 2016; 23:944-956. [DOI: 10.1177/1526602816668305] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Purpose: To investigate the total fluoroscopy time and radiation exposure dose during endovascular aortic repairs using mobile, fixed, or fixed C-arms with 3-dimensional image fusion (3D-IF). Methods: A systematic search was performed to identify original articles reporting fluoroscopy time (FT) and the kerma area product (KAP) during endovascular aortic repairs. Data were grouped by noncomplex or complex (fenestrated, branched, or chimney) repairs and stratified by type of C-arm. The search identified 27 articles containing 51 study groups (35 noncomplex and 16 complex) that included 3444 patients. Random-effects meta-analysis and meta-regression models were used to calculate the pooled mean estimates of KAP and FT, as well as any effect of equipment or type of intervention. Results are presented with the 95% confidence interval and the statistical heterogeneity ( I2). Results: Within the noncomplex procedure studies, a significant (p<0.001) increase was found in the pooled mean KAP estimate in the fixed C-arm group (181 Gy·cm2, 95% CI 129 to 233; I2=99.7) compared with the mobile C-arm (78 Gy·cm2, 95% CI 59.6 to 97.3; I2=99.6). For complex cases, use of 3D-IF showed a significantly (p<0.001) lower mean KAP (139 Gy·cm2, 95% CI 85 to 191; I2=94%) compared to using fixed C-arms without 3D-IF (487 Gy·cm2, 95% CI 331 to 643; I2=94%). Conclusion: For equivalent fluoroscopy times, the use of a fixed C-arm in noncomplex procedures leads to higher patient radiation doses compared to a mobile C-arm. Complex procedures, which are predominantly performed using fixed C-arms, are associated with the highest radiation dose per intervention. Using fixed C-arms combined with 3D-IF techniques during complex cases might seem an adequate method to compensate for the higher radiation doses measured when a fixed C-arm is used.
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Affiliation(s)
| | - Johannes B. Reitsma
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, the Netherlands
| | - Frans L. Moll
- Department of Vascular Surgery, University Medical Center Utrecht, the Netherlands
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Moriña D, Grellier J, Carnicer A, Pernot E, Ryckx N, Cardis E. InterCardioRisk: a novel online tool for estimating doses of ionising radiation to occupationally-exposed medical staff and their associated health risks. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:561-578. [PMID: 27460876 DOI: 10.1088/0952-4746/36/3/561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Those working in interventional cardiology and related medical procedures are potentially subject to considerable exposure to x-rays. Two types of tissue of particular concern that may receive considerable doses during such procedures are the lens of the eye and the brain. Ocular radiation exposure results in lens changes that, with time, may progress to partial or total lens opacification (cataracts). In the early stages, such opacities do not result in visual disability; the severity of such changes tends to increase progressively with dose and time until vision is impaired and cataract surgery is required. Scattered radiation doses to the eye lens of an interventional cardiologist in typical working conditions can exceed 34 μGy min-1 in high-dose fluoroscopy modes and 3 μGy per image during image acquisition (instantaneous rate values) when radiation protection tools are not used. A causal relation between exposure to ionising radiation and increased risk of brain and central nervous system tumours has been shown in a number of studies. Although absorbed doses to the brain in interventional cardiology procedures are lower than those to the eye lens by a factor between 3.40 and 8.08 according to our simulations, doses to both tissues are among the highest occupational radiation doses documented for medical staff whose work involves exposures to x-rays. We present InterCardioRisk, a tool featuring an easy-to-use web interface that provides a general estimation of both cumulated absorbed doses experienced by medical staff exposed in the interventional cardiology setting and their estimated associated health risks. The tool is available at http://intercardiorisk.creal.cat.
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Affiliation(s)
- David Moriña
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain. Universitat Pompeu Fabra (UPF), Barcelona, Spain. CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain. Unit of Infections and Cancer (UNIC), Cancer Epidemiology Research Program (CERP), Catalan Institute of Oncology (ICO)-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. Grups de Recerca d'Àfrica i Amèrica Llatines (GRAAL)-Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
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Corredoira E, Vañó E, Alejo L, Ubeda C, Gutiérrez-Larraya F, Garayoa J. Biplane interventional pediatric system with cone-beam CT: dose and image quality characterization for the default protocols. J Appl Clin Med Phys 2016; 17:357-376. [PMID: 27455474 PMCID: PMC5690060 DOI: 10.1120/jacmp.v17i4.5828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 02/28/2016] [Accepted: 02/26/2016] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone-beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18-FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3-12 when comparing cine and fluoroscopy frames. The biggest difference in the signal-to- noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440 × 1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720 × 720 pixels and in binned mode. The high-contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low-dose protocol. Although the amount of noise present in the images acquired with the low-dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric-specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy, but with very good spatial resolution.
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Choi MH, Choi BG, Jung SE, Byun JY. Factors Related to Radiation Exposure during Lumbar Spine Intervention. J Korean Med Sci 2016; 31 Suppl 1:S55-8. [PMID: 26908989 PMCID: PMC4756343 DOI: 10.3346/jkms.2016.31.s1.s55] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 09/01/2015] [Indexed: 11/20/2022] Open
Abstract
Fluoroscopy guidance is useful to confirm anatomical landmark and needle location for spine intervention; however, it can lead to radiation exposure in patients, physicians, and medical staff. Physicians who used fluoroscopy should be cognizant of radiation exposure and intend to minimize radiation dose. We retrospectively reviewed three lumbar spine intervention procedures (nerve root block, medial branch block, and facet joint block) at our institution between June and December, 2014. We performed 268 procedures on 220 patients and found significant difference in radiation dose between two groups classified by performing physicians. The physician who controlled the fluoroscopy unit directly used significantly shorter fluoroscopy (6 seconds) that resulted in a smaller radiation dose (dose area product [DAP] 0.59 Gy∙cm(2)) than the physician supervising the radiographer controlling the fluoroscopy unit (72 seconds, DAP 5.31 Gy∙cm(2), P < 0.001). The analysis indicates that the difference in fluoroscopy time depends on whether a physician or a radiographer controls the fluoroscopy unit.
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Affiliation(s)
- Moon Hyung Choi
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Byung Gil Choi
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Seung Eun Jung
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jae Young Byun
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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de las Heras H, Torres R, Fernández-Soto JM, Vañó E. Objective criteria for acceptability and constancy tests of digital subtraction angiography. Phys Med 2015; 32:272-6. [PMID: 26522881 DOI: 10.1016/j.ejmp.2015.10.089] [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: 08/28/2015] [Revised: 10/13/2015] [Accepted: 10/14/2015] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Demonstrate an objective procedure to quantify image quality in digital subtraction angiography (DSA) and suggest thresholds for acceptability and constancy tests. METHODS Series of images were obtained in a DSA system simulating a small (paediatric) and a large patient using the dynamic phantom described in the IEC and DIN standards for acceptance tests of DSA equipment. Image quality was quantified using measurements of contrast-to-noise ratio (CNR). Overall scores combining the CNR of 10-100 mg/ml Iodine at a vascular diameter of 1-4 mm in a homogeneous background were defined. Phantom entrance surface air kerma (Ka,e) was measured with an ionisation chamber. RESULTS The visibility of a low-contrast vessel in DSA images has been identified with a CNR value of 0.50 ± 0.03. Despite using 14 times more Ka,e (8.85 vs 0.63 mGy/image), the protocol for large patients showed a decrease in the overall score CNRsum of 67% (4.21 ± 0.06 vs 2.10 ± 0.05). The uncertainty in the results of the objective method was below 5%. CONCLUSION Objective evaluation of DSA images using CNR is feasible with dedicated phantom measurements. An objective methodology has been suggested for acceptance tests compliant with the IEC/DIN standards. The defined overall scores can serve to fix a reproducible baseline for constancy tests, as well as to study the device stability within one acquisition series and compare different imaging protocols. This work provides aspects that have not been included in the recent European guidelines on Criteria for Acceptability of Medical Radiological Equipment.
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Affiliation(s)
- Hugo de las Heras
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), c. Profesor Martín Lagos, S/N, 28040 Madrid, Spain.
| | - Ricardo Torres
- Servicio de Radiofísica y Protección Radiológica. Hospital Universitario Río Hortega, c/ Dulzaina, 2, 47012 Valladolid, Spain
| | - José Miguel Fernández-Soto
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), c. Profesor Martín Lagos, S/N, 28040 Madrid, Spain; Departamento de Radiología, Facultad de Medicina, Universidad Complutense, Avda. Complutense s/n, 28040 Madrid, Spain
| | - Eliseo Vañó
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), c. Profesor Martín Lagos, S/N, 28040 Madrid, Spain; Departamento de Radiología, Facultad de Medicina, Universidad Complutense, Avda. Complutense s/n, 28040 Madrid, Spain
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NOF EYAL, LANE CHRISTOPHER, CAZALAS MAXIME, CUCHET-SOUBELET ELISABETH, MICHAUD GREGORYF, JOHN ROYM, TEDROW USHA, KOPLAN BRUCEA, STEVENSON WILLIAMG, EPSTEIN LAURENCEM. Reducing Radiation Exposure in the Electrophysiology Laboratory: It is More Than Just Fluoroscopy Times! PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2014; 38:136-45. [DOI: 10.1111/pace.12544] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/29/2014] [Accepted: 10/19/2014] [Indexed: 12/18/2022]
Affiliation(s)
- EYAL NOF
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
- Leviev Heart Center; Sheba Medical Center; Tel Hashomer Israel
| | - CHRISTOPHER LANE
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
| | | | | | - GREGORY F. MICHAUD
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
| | - ROY M. JOHN
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
| | - USHA TEDROW
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
| | - BRUCE A. KOPLAN
- Cardiovascular Division; Brigham and Women's Hospital; Boston Massachusetts
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