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Tonkopi E, Tetteh MA, Gunn C, Ashraf H, Rusten SL, Safi P, Tinsoe NS, Colford K, Ouellet O, Naimi S, Johansen S. A multi-institutional assessment of low-dose protocols in chest computed tomography: Dose and image quality. Acta Radiol Open 2024; 13:20584601241228220. [PMID: 38304118 PMCID: PMC10829498 DOI: 10.1177/20584601241228220] [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: 09/08/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Background Low-dose CT (LDCT) chest protocols have widespread clinical applications for many indications; as a result, there is a need for protocol assessment prior to standardization. Dalhousie University and Oslo Metropolitan University have a formally established cooperative relationship. Purpose The purpose is to assess radiation dose and image quality for LDCT chest protocols in seven different hospital locations in Norway and Canada. Material and methods Retrospective dosimetry data, volumetric CT dose index (CTDIvol), and dose length product (DLP) from 240 average-sized patients as well as CT protocol parameters were included in the survey. Effective dose (ED) and size-specific dose estimate (SSDE) were calculated for each examination. For a quantitative image quality analysis, noise, CT number, and signal-to-noise ratio (SNR) were determined for three regions in the chest. The contrast-to-noise ratio (CNR) was calculated for lung parenchyma in comparison to the subcutaneous fat. Differences in dose and image quality were evaluated by a single-factor ANOVA test. A two-sample t-test was performed to determine differences in means between individual scanners. Results The ANOVA test revealed significant differences (p < .05) in dose values for all scanners, including identical scanner models. Statistically significant differences (p < .05) were determined in mean values of the SNR distributions between the scanners in all three measured regions in the chest, as well as the CNR values. Conclusion The observed variations in dose and image quality measurements, even within the same hospitals and between identical scanner models, indicate a potential for protocol optimization in the involved hospitals in both countries.
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Affiliation(s)
- Elena Tonkopi
- Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada
- Department of Radiation Oncology, Dalhousie University, Halifax, NS, Canada
- Department of Diagnostic Imaging, Nova Scotia Health Authority, Halifax, NS, Canada
| | - Mercy Afadzi Tetteh
- Department of Diagnostic Imaging, Akershus University Hospital, Loerenskog, Norway
| | - Catherine Gunn
- Department of Radiation Oncology, Dalhousie University, Halifax, NS, Canada
- School of Health Sciences, Dalhousie University, Halifax, NS, Canada
| | - Haseem Ashraf
- Department of Diagnostic Imaging, Akershus University Hospital, Loerenskog, Norway
- Medicine Faculty, University of Oslo, Oslo Norway
| | - Sigrid Lia Rusten
- Health Faculty, Department of Life Sciences and Health, Oslo Metropolitan University Oslo, Norway
| | - Perkhah Safi
- Health Faculty, Department of Life Sciences and Health, Oslo Metropolitan University Oslo, Norway
| | - Nora Suu Tinsoe
- Health Faculty, Department of Life Sciences and Health, Oslo Metropolitan University Oslo, Norway
| | - Kylie Colford
- School of Health Sciences, Dalhousie University, Halifax, NS, Canada
| | - Olivia Ouellet
- School of Health Sciences, Dalhousie University, Halifax, NS, Canada
| | - Salma Naimi
- Department of Diagnostic Imaging, Akershus University Hospital, Loerenskog, Norway
| | - Safora Johansen
- Health Faculty, Department of Life Sciences and Health, Oslo Metropolitan University Oslo, Norway
- Department of Cancer Treatment, Oslo University Hospital, Oslo, Norway
- Health and Social Science Cluster, Singapore Institute of Technology, Singapore
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Mørup SD, Stowe J, Kusk MW, Precht H, Foley S. The impact of ASiR-V on abdominal CT radiation dose and image quality – A phantom study. J Med Imaging Radiat Sci 2022; 53:453-459. [DOI: 10.1016/j.jmir.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/29/2022]
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Hu X, Yu Y. Explore the Value of Dual Source Computer Tomography Automatic Tube Current Regulation in Reducing the Radiation Dose of CTA in Lower Extremity Vessels. Front Surg 2022; 9:896370. [PMID: 35592130 PMCID: PMC9112657 DOI: 10.3389/fsurg.2022.896370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
Objective To investigate the value of dual source computer tomography automatic tube current regulation in reducing the radiation dose of CTA in lower limb vessels. Methods From February 2020 to December 2021, 64 patients with lower limb artery CTA were selected in our hospital because of the symptoms of foot ischemia. According to the random number table, patients were divided into control group (treated with fixed tube current technology) and observation group (treated with automatic tube current regulation technology), with 32 cases in each group. All patients underwent a dual source computer tomography scan. Control group: tube voltage 120 kV, tube current 250 mA; Observation group: tube voltage was 80 kV, and reference tube current was 80–380 mA. Other scanning conditions of patients in the two groups were the same. CTDIvol, DLP and calculated SNR and CNR were recorded to obtain the ED. Results The values of CTDIvol, DLP and ED in the observation group were lower than those in the control group (P < 0.05). There was no significant difference in CT value, SD value, SNR value and CNR value of the femoral artery segment, popliteal artery segment and posterior tibial artery segment between the two groups (P > 0.05). The image quality scores of patients in the control group were slightly higher than those in the observation group, but there was no statistical difference between the two groups (P > 0.05). Conclusion The application of dual source computer tomography automatic tube current adjustment technology in CTA examination of lower limb vessels can automatically adjust the compensation output and realize the output of different tube currents in different thicknesses, densities and angles. On the premise of not affecting the image quality, the radiation dose in the scanning process to the maximum extent, and reasonably protect the examined patients.
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Affiliation(s)
- Xin Hu
- Department of Guangdong Armed Police Corps Hospital, Medical Engineering, Guangzhou, Guangdong, China
| | - Yi Yu
- School of Foreign Languages of Guangdong University of Technology, Guangzhou, Guangdong, China
- Correspondence: Yi Yu
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Diagnostic accuracy of ultra-low-dose CT for torsion measurement of the lower limb. Eur Radiol 2020; 31:3574-3581. [PMID: 33241518 PMCID: PMC8249276 DOI: 10.1007/s00330-020-07528-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/24/2020] [Accepted: 11/16/2020] [Indexed: 01/12/2023]
Abstract
Objectives The study aimed to investigate the diagnostic performance of simulated ultra-low-dose CT (ULD-CT) for torsion measurement of the lower limb. Methods Thirty retrospectively identified patients were included (32.3 ± 14.2 years; 14 women, 16 men). ULD-CT simulations were generated at dose levels of 100%, 10%, 5%, and 1% using two reconstruction methods: standard filtered back projection (FBP) and iterative reconstruction (ADMIRE). Two readers measured the lower limb torsion in all data sets. The readers also captured image noise in standardized anatomical landmarks. All data sets were evaluated regarding subjective diagnostic confidence (DC; 5-point Likert scale). Effective radiation dose of the original data sets and the simulated ULD-CT was compared. Results There was no significant difference of measured lower limb torsion in any simulated dose level compared to the original data sets in both readers. Dose length product (DLP) of the original examinations was 402.1 ± 4.3 mGy cm, which resulted in an effective radiation dose of 4.00 ± 2.12 mSv. Calculated effective radiation dose in ULD-CT at 1% of the original dose was 0.04 mSv. Image noise increased significantly with dose reduction (p < 0.0001) and was dependent on the reconstructional method (p < 0.0001) with less noise using ADMIRE compared to FBP. Both readers rated DC at doses 100%, 10%, and 5% with 5.0/5: there were no ratings worse than 3/5 at 1% dose level. Conclusions The results suggest that radiation dose reduction down to 1% of original CT dose levels may be achieved in CT torsion measurements of the lower limb without compromising diagnostic accuracy. Key Points • Modern CT delivers exceptional high image quality in musculoskeletal imaging, especially for evaluation of osseous structures. • Usually, this high image quality is accompanied by significant radiation exposure to the patient and may not always be required for the intended purpose, e.g., pure delineation of cortical bone of the lower limb. • This study shows the tremendous prospects of radiation dose reduction without compromising diagnostic confidence in CT torsion measurement of the lower limb.
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Vergalasova I, McKenna M, Yue NJ, Reyhan M. Impact of computed tomography (CT) reconstruction kernels on radiotherapy dose calculation. J Appl Clin Med Phys 2020; 21:178-186. [PMID: 32889789 PMCID: PMC7497921 DOI: 10.1002/acm2.12994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 06/27/2020] [Accepted: 07/11/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To quantitatively evaluate the effect of computed tomography (CT) reconstruction kernels on various dose calculation algorithms with heterogeneity correction. METHODS The gammex electron density (ED) Phantom was scanned with the Siemens PET/CT Biograph20 mCT and reconstructed with twelve different kernel options. Hounsfield unit (HU) vs electron density (ED) curves were generated to compare absolute differences. Scans were repeated under head and pelvis protocols and reconstructed per H40s (head) and B40s (pelvis) kernels. In addition, raw data from a full-body patient scan were also reconstructed using the four B kernels. Per reconstruction, photon (3D and VMAT), electron (18 and 20 MeV) and proton (single field) treatment plans were generated using Varian Eclipse dose calculation algorithms. Photon and electron plans were also simulated to pass through cortical bone vs liver plugs of the phantom for kernel comparison. Treatment field monitor units (MU) and isodose volumes were compared across all scenarios. RESULTS The twelve kernels resulted in minor differences in HU, except at the extreme ends of the density curve with a maximum absolute difference of 55.2 HU. The head and pelvis scans of the phantom resulted in absolute HU differences of up to 49.1 HU for cortical bone and 45.1 HU for lung 300, which is a relative difference of 4.1% and 6.2%, respectively. MU comparisons across photon and proton calculation algorithms for the patient and phantom scans were within 1-2 MU, with a maximum difference of 5.4 MU found for the 20 MeV electron plan. The 20MeV electron plan also displayed maximum differences in isodose volumes of 20.4 cc for V90%. CONCLUSION Clinically insignificant differences were found among the various kernel generated plans for photon and proton plans calculated on patient and phantom scan data. However, differences in isodose volumes found for higher energy electron plans amongst the kernels may have clinical implications for prescribing dose to an isodose level.
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Affiliation(s)
- Irina Vergalasova
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | - Michael McKenna
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | - Ning Jeff Yue
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
| | - Meral Reyhan
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, NJ, USA
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Establishment of Submillisievert Abdominal CT Protocols With an In Vivo Swine Model and an Anthropomorphic Phantom. AJR Am J Roentgenol 2020; 215:685-694. [DOI: 10.2214/ajr.19.22053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Sin D, McLennan G, Rengier F, Haddadin I, Heresi GA, Bartholomew JR, Fink MA, Thompson D, Partovi S. Acute pulmonary embolism multimodality imaging prior to endovascular therapy. Int J Cardiovasc Imaging 2020; 37:343-358. [PMID: 32862293 PMCID: PMC7456521 DOI: 10.1007/s10554-020-01980-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 08/19/2020] [Indexed: 12/15/2022]
Abstract
The manuscript discusses the application of CT pulmonary angiography, ventilation–perfusion scan, and magnetic resonance angiography to detect acute pulmonary embolism and to plan endovascular therapy. CT pulmonary angiography offers high accuracy, speed of acquisition, and widespread availability when applied to acute pulmonary embolism detection. This imaging modality also aids the planning of endovascular therapy by visualizing the number and distribution of emboli, determining ideal intra-procedural catheter position for treatment, and signs of right heart strain. Ventilation–perfusion scan and magnetic resonance angiography with and without contrast enhancement can also aid in the detection and pre-procedural planning of endovascular therapy in patients who are not candidates for CT pulmonary angiography.
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Affiliation(s)
- David Sin
- Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Gordon McLennan
- Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Fabian Rengier
- Section of Emergency Radiology, Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ihab Haddadin
- Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Gustavo A Heresi
- Department of Pulmonary and Critical Care Medicine, Respiratory Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - John R Bartholomew
- Section of Vascular Medicine, Heart and Vascular Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Matthias A Fink
- Section of Emergency Radiology, Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Dustin Thompson
- Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA
| | - Sasan Partovi
- Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA.
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