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Markart S, Fischer TS, Wildermuth S, Dietrich TJ, Alkadhi H, Leschka S, Guesewell S, Ditchfield MR, Oezden I, Lutters G, Waelti SL. Organ-based tube current modulation and bismuth eye shielding in pediatric head computed tomography. Pediatr Radiol 2022; 52:2584-2594. [PMID: 35836016 DOI: 10.1007/s00247-022-05410-x] [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: 07/13/2021] [Revised: 12/23/2021] [Accepted: 05/30/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Exposure of the eye lens to ionizing radiation results in cataract. Several dose optimization techniques to protect the lens are available for computed tomography (CT). OBJECTIVE The radiation dose to the eye lens, volume CT dose index (CTDIvol) and image quality of various methods of dose optimization were evaluated for pediatric head CT: automated tube current modulation (ATCM), automated tube voltage selection (ATVS), organ-based tube current modulation (OBTCM) and bismuth shielding. MATERIALS AND METHODS An anthropomorphic phantom of a 5-year-old child was scanned with nine protocols: no dose optimization technique and then adding different dose optimization techniques alone and in combination. Dose to the eye, thyroid and breast were estimated using metal oxide semiconductor field effect transistor (MOSFET) dosimetry. CTDIvol, influence of timing of shield placement, image noise and attenuation values in 13 regions of interest of the head and subjective image quality were compared. RESULTS The eye shield significantly reduced the eye lens dose when used alone, to a similar degree as when using all software-based techniques together. When used in combination with software-based techniques, the shield reduced the eye lens dose by up to 45% compared to the no dose optimization technique. Noise was significantly increased by the shield, most pronounced in the anterior portion of the eye. CONCLUSION The combination of ATCM, ATVS, OBTCM and a bismuth shield, with the shield placed after acquiring the localizer image, should be considered to reduce the radiation dose to the eye lens in pediatric head CT.
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Affiliation(s)
- Stefan Markart
- Department of Radiology and Nuclear Medicine, Children's Hospital of Eastern Switzerland, Claudiusstrasse 6, 9006, St. Gallen, Switzerland
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Tim S Fischer
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Simon Wildermuth
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Tobias J Dietrich
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
- Department of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Hatem Alkadhi
- Department of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Sebastian Leschka
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Sabine Guesewell
- Clinical Trials Unit, Biostatistics, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Michael R Ditchfield
- Department of Diagnostic Imaging, Monash Children's Hospital, Clayton, Australia
| | - Ismail Oezden
- Radiation Protection and Medical Physics, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Gerd Lutters
- Radiation Protection and Medical Physics, Cantonal Hospital Aarau, Aarau, Switzerland
| | - Stephan L Waelti
- Department of Radiology and Nuclear Medicine, Children's Hospital of Eastern Switzerland, Claudiusstrasse 6, 9006, St. Gallen, Switzerland.
- Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
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Muhammad N, Sabarudin A, Ismail N, Karim M. A systematic review and meta-analysis of radiation dose exposure from computed tomography examination of thorax-abdomen-pelvic regions among paediatric population. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.109148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Evaluation of an organ-based tube current modulation tool in pediatric CT examinations. Eur Radiol 2020; 30:5728-5737. [PMID: 32435930 PMCID: PMC7476969 DOI: 10.1007/s00330-020-06888-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/16/2020] [Accepted: 04/10/2020] [Indexed: 11/26/2022]
Abstract
Objectives To investigate the effect of an organ-based tube current modulation (OTCM) technique on organ absorbed dose and assess image quality in pediatric CT examinations. Methods Four physical anthropomorphic phantoms that represent the average individual as neonate, 1-year-old, 5-year-old, and 10-year-old were used. Standard head and thorax acquisitions were performed with automatic tube current modulation (ATCM) and ATCM+OTCM. Dose calculations were performed by means of Monte Carlo simulations. Radiation dose was measured for superficial and centrally located radiosensitive organs. The angular range of the OTCM exposure window was determined for different tube rotation times (t) by means of a solid-state detector. Image noise was measured as the standard deviation of the Hounsfield unit value in regions of interest drawn at selected anatomical sites. Results ATCM+OTCM resulted in a reduction of radiation dose to all radiosensitive organs. In head, eye lens dose was reduced by up to 13% in ATCM+OTCM compared with ATCM. In thorax, the corresponding reduction for breast dose was up to 10%. The angular range of the OTCM exposure window decreased with t. For t = 0.4 s, the angular range was limited to 74° in head and 135° for thorax. Image noise was significantly increased in ATCM+OTCM acquisitions across most examined phantoms (p < 0.05). Conclusions OTCM reduces radiation dose to exposed radiosensitive organs with the eye lens and breast buds exhibiting the highest dose reduction. The OTCM exposure window is narrowed at short t. An increase in noise is inevitable in images located within the OTCM-activated imaged volume. Key Points • In pediatric CT, organ-based tube current modulation reduces radiation dose to all major primarily exposed radiosensitive organs. • Image noise increases within the organ-based tube current modulation enabled imaged volume. • The angular range of the organ-based tube current modulation low exposure window is reduced with tube rotation time.
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Mussmann BR, Mørup SD, Skov PM, Foley S, Brenøe AS, Eldahl F, Jørgensen GM, Precht H. Organ-based tube current modulation in chest CT. A comparison of three vendors. Radiography (Lond) 2020; 27:1-7. [PMID: 32402706 DOI: 10.1016/j.radi.2020.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Organ-based tube current modulation (OBTCM) is designed for anterior dose reduction in Computed Tomography (CT). The purpose was to assess dose reduction capability in chest CT using three organ dose modulation systems at different kVp settings. Furthermore, noise, diagnostic image quality and tumour detection was assessed. METHODS A Lungman phantom was scanned with and without OBTCM at 80-135/140 kVp using three CT scanners; Canon Aquillion Prime, GE Revolution CT and Siemens Somatom Flash. Thermo-luminescent dosimeters were attached to the phantom surface and all scans were repeated five times. Image noise was measured in three ROIs at the level of the carina. Three observers visually scored the images using a fivestep scale. A Wilcoxon Signed-Rank test was used for statistical analysis of differences. RESULTS Using the GE revolution CT scanner, dose reductions between 1.10 mSv (12%) and 1.56 mSv (24%) (p < 0.01) were found in the anterior segment and no differences posteriorly and laterally. Total dose reductions between 0.64 (8%) and 0.91 mSv (13%) were found across kVp levels (p < 0.00001). Maximum noise increase with OBTCM was 0.8 HU. With the Canon system, anterior dose reductions of 6-10% and total dose reduction of 0.74-0.76 mSv across kVp levels (p < 0.001) were found with a maximum noise increase of 1.1 HU. For the Siemens system, dose increased by 22-51% anteriorly; except at 100 kVp where no dose difference was found. Noise decreased by 1 to 1.5 HU. CONCLUSION Organ based tube current modulation is capable of anterior and total dose reduction with minimal loss of image quality in vendors that do not increase posterior dose. IMPLICATIONS FOR PRACTICE This research highlights the importance of being familiar with dose reduction technologies.
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Affiliation(s)
- B R Mussmann
- Department of Radiology, Odense University Hospital, Denmark; Department of Clinical Research, University of Southern Denmark; Faculty of Health Sciences, Oslo Metropolitan University, Norway.
| | - S D Mørup
- Conrad Research Programme, Centre for Applied Welfare Research, University College Lillebaelt, Denmark.
| | - P M Skov
- Department of Radiology, Odense University Hospital, Denmark.
| | - S Foley
- Radiography & Diagnostic Imaging, School of Medicine, University College Dublin, Ireland
| | - A S Brenøe
- Department of Radiology, Odense University Hospital, Denmark.
| | - F Eldahl
- Department of Radiology, Odense University Hospital, Denmark.
| | - G M Jørgensen
- Department of Radiology, Odense University Hospital, Denmark.
| | - H Precht
- Conrad Research Programme, Centre for Applied Welfare Research, University College Lillebaelt, Denmark; Medical Research Department, Odense University Hospital, Svendborg, Denmark.
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Koc GG, Koc Z, Kaniyev T, Kokangul A. Thorax CT Dose Reduction Based on Patient Features: Effect of Patient Characteristics on Image Quality and Effective Dose. HEALTH PHYSICS 2019; 116:736-745. [PMID: 30908322 DOI: 10.1097/hp.0000000000001008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Computed tomography (CT) radiation dose reduction is vital without compromising image quality. The aim was to determine the effects of patient characteristics on the received radiation dose and image quality in chest CT examinations and to be able to predict dose and image quality prior to scanning. Consecutive 230 patients underwent routine chest CT examinations were included. CT examination and patients input parameters were recorded for each patient. The effect of patients' demographics/anthropometrics on received dose and image quality was investigated by linear regression analysis. All parameters were evaluated using an artificial neural network (ANN). Of all parameters, patient demographics/anthropometrics were found to be 98% effective in calculating dose reduction. Using ANN on 60 new patients was more than 90% accurate for output parameters and 91% for image quality. Patient characteristics have a significant impact on radiation dose and image quality. Dose and image quality can be determined before CT. This will allow setting the most appropriate scanning parameters before the CT scan.
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Affiliation(s)
- Gizem Gul Koc
- Faculty of Industrial Engineering, Cukurova University, ADANA, Turkey
| | - Zafer Koc
- Faculty of Medicine, Department of Radiology, Baskent University, ANKARA, Turkey
| | - Tahir Kaniyev
- Faculty of Industrial Engineering, TOOB Economy University, ANKARA, Turkey
| | - Ali Kokangul
- Faculty of Industrial Engineering, Cukurova University, ADANA, Turkey
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Martine RJ, Santangelo T, Colas L, Jean-Baptiste F, Duhamel A, Deschildre A, Remy J. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT. Pediatr Radiol 2017; 47:161-168. [PMID: 27830296 DOI: 10.1007/s00247-016-3731-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 09/24/2016] [Accepted: 10/07/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. OBJECTIVE To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. MATERIALS AND METHODS We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. RESULTS CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol32) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP32 was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP32, CTDIvol32 and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). CONCLUSION This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP32, 0.78-1.25 mGy for the CTDIvol32 and 1.6-2.1 mGy for the SSDE.
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Affiliation(s)
- Remy-Jardin Martine
- Department of Thoracic Imaging, Hospital Calmette, CHU Lille (EA 2694) University of Lille, F-59000, Lille, France.
| | - Teresa Santangelo
- Department of Thoracic Imaging, Hospital Calmette, CHU Lille (EA 2694) University of Lille, F-59000, Lille, France.,Department of Imaging, Bambino Gesù Children's Hospital, Rome, Italy
| | - Lucie Colas
- Department of Thoracic Imaging, Hospital Calmette, CHU Lille (EA 2694) University of Lille, F-59000, Lille, France
| | - Faivre Jean-Baptiste
- Department of Thoracic Imaging, Hospital Calmette, CHU Lille (EA 2694) University of Lille, F-59000, Lille, France
| | - Alain Duhamel
- Department of Biostatistics; CHU Lille, University of Lille (EA 2694) , F-59000, Lille, France
| | - Antoine Deschildre
- Department of Pediatric Pulmonology,, CHU Lille - University of Lille, Lille, France
| | - Jacques Remy
- Department of Thoracic Imaging, Hospital Calmette, CHU Lille (EA 2694) University of Lille, F-59000, Lille, France
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Boos J, Aissa J, Lanzman RS, Heusch P, Schimmöller L, Schleich C, Thomas C, Antoch G, Kröpil P. CT angiography of the aorta using 80 kVp in combination with sinogram-affirmed iterative reconstruction and automated tube current modulation: Effects on image quality and radiation dose. J Med Imaging Radiat Oncol 2016; 60:187-93. [DOI: 10.1111/1754-9485.12425] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 11/04/2015] [Indexed: 01/16/2023]
Affiliation(s)
- Johannes Boos
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Joel Aissa
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Rotem S Lanzman
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Philipp Heusch
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Lars Schimmöller
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Christoph Schleich
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Christoph Thomas
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Patric Kröpil
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
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