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Bos D, Demircioğlu A, Neuhoff J, Haubold J, Zensen S, Opitz MK, Drews MA, Li Y, Styczen H, Forsting M, Nassenstein K. Assessment of image quality and impact of deep learning-based software in non-contrast head CT scans. Sci Rep 2024; 14:11810. [PMID: 38782976 PMCID: PMC11116440 DOI: 10.1038/s41598-024-62394-4] [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: 01/30/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
In this retrospective study, we aimed to assess the objective and subjective image quality of different reconstruction techniques and a deep learning-based software on non-contrast head computed tomography (CT) images. In total, 152 adult head CT scans (77 female, 75 male; mean age 69.4 ± 18.3 years) obtained from three different CT scanners using different protocols between March and April 2021 were included. CT images were reconstructed using filtered-back projection (FBP), iterative reconstruction (IR), and post-processed using a deep learning-based algorithm (PS). Post-processing significantly reduced noise in FBP-reconstructed images (up to 15.4% reduction) depending on the protocol, leading to improvements in signal-to-noise ratio of up to 19.7%. However, when deep learning-based post-processing was applied to FBP images compared to IR alone, the differences were inconsistent and partly non-significant, which appeared to be protocol or site specific. Subjective assessments showed no significant overall improvement in image quality for all reconstructions and post-processing. Inter-rater reliability was low and preferences varied. Deep learning-based denoising software improved objective image quality compared to FBP in routine head CT. A significant difference compared to IR was observed for only one protocol. Subjective assessments did not indicate a significant clinical impact in terms of improved subjective image quality, likely due to the low noise levels in full-dose images.
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Affiliation(s)
- Denise Bos
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany.
| | - Aydin Demircioğlu
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Julia Neuhoff
- Faculty of Medicine, University Duisburg-Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Johannes Haubold
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Sebastian Zensen
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Marcel K Opitz
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Marcel A Drews
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Yan Li
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Hanna Styczen
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Michael Forsting
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
| | - Kai Nassenstein
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45147, Essen, Germany
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Kataria B, Woisetschläger M, Nilsson Althén J, Sandborg M, Smedby Ö. Image quality in CT thorax: effect of altering reconstruction algorithm and tube load. RADIATION PROTECTION DOSIMETRY 2024; 200:504-514. [PMID: 38369635 PMCID: PMC10997858 DOI: 10.1093/rpd/ncae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/03/2023] [Accepted: 01/09/2024] [Indexed: 02/20/2024]
Abstract
Non-linear properties of iterative reconstruction (IR) algorithms can alter image texture. We evaluated the effect of a model-based IR algorithm (advanced modelled iterative reconstruction; ADMIRE) and dose on computed tomography thorax image quality. Dual-source scanner data were acquired at 20, 45 and 65 reference mAs in 20 patients. Images reconstructed with filtered back projection (FBP) and ADMIRE Strengths 3-5 were assessed independently by six radiologists and analysed using an ordinal logistic regression model. For all image criteria studied, the effects of tube load 20 mAs and all ADMIRE strengths were significant (p < 0.001) when compared to reference categories 65 mAs and FBP. Increase in tube load from 45 to 65 mAs showed image quality improvement in three of six criteria. Replacing FBP with ADMIRE significantly improves perceived image quality for all criteria studied, potentially permitting a dose reduction of almost 70% without loss in image quality.
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Affiliation(s)
- Bharti Kataria
- Department of Radiology, Linköping University, SE-581 85, Linköping, Sweden
- Department of Health, Medicine & Caring Sciences, Linköping University, SE-581 83 Linköping, Sweden
- Center for Medical Image Science & Visualisation (CMIV), Linköping University, SE-581 83 Linköping, Sweden
| | - Mischa Woisetschläger
- Department of Radiology, Linköping University, SE-581 85, Linköping, Sweden
- Department of Health, Medicine & Caring Sciences, Linköping University, SE-581 83 Linköping, Sweden
- Center for Medical Image Science & Visualisation (CMIV), Linköping University, SE-581 83 Linköping, Sweden
| | - Jonas Nilsson Althén
- Department of Health, Medicine & Caring Sciences, Linköping University, SE-581 83 Linköping, Sweden
- Department of Medical Physics, Linköping University, SE-581 85 Linköping, Sweden
| | - Michael Sandborg
- Department of Health, Medicine & Caring Sciences, Linköping University, SE-581 83 Linköping, Sweden
- Center for Medical Image Science & Visualisation (CMIV), Linköping University, SE-581 83 Linköping, Sweden
- Department of Medical Physics, Linköping University, SE-581 85 Linköping, Sweden
| | - Örjan Smedby
- Department of Biomedical Engineering and Health Systems (MTH), KTH Royal Institute of Technology, SE-141 57 Stockholm, Sweden
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Steuwe A, Kamp B, Afat S, Akinina A, Aludin S, Bas EG, Berger J, Bohrer E, Brose A, Büttner SM, Ehrengut C, Gerwing M, Grosu S, Gussew A, Güttler F, Heinrich A, Jiraskova P, Kloth C, Kottlors J, Kuennemann MD, Liska C, Lubina N, Manzke M, Meinel FG, Meyer HJ, Mittermeier A, Persigehl T, Schmill LP, Steinhardt M, The Racoon Study Group, Antoch G, Valentin B. Standardization of a CT Protocol for Imaging Patients with Suspected COVID-19-A RACOON Project. Bioengineering (Basel) 2024; 11:207. [PMID: 38534481 DOI: 10.3390/bioengineering11030207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 03/28/2024] Open
Abstract
CT protocols that diagnose COVID-19 vary in regard to the associated radiation exposure and the desired image quality (IQ). This study aims to evaluate CT protocols of hospitals participating in the RACOON (Radiological Cooperative Network) project, consolidating CT protocols to provide recommendations and strategies for future pandemics. In this retrospective study, CT acquisitions of COVID-19 patients scanned between March 2020 and October 2020 (RACOON phase 1) were included, and all non-contrast protocols were evaluated. For this purpose, CT protocol parameters, IQ ratings, radiation exposure (CTDIvol), and central patient diameters were sampled. Eventually, the data from 14 sites and 534 CT acquisitions were analyzed. IQ was rated good for 81% of the evaluated examinations. Motion, beam-hardening artefacts, or image noise were reasons for a suboptimal IQ. The tube potential ranged between 80 and 140 kVp, with the majority between 100 and 120 kVp. CTDIvol was 3.7 ± 3.4 mGy. Most healthcare facilities included did not have a specific non-contrast CT protocol. Furthermore, CT protocols for chest imaging varied in their settings and radiation exposure. In future, it will be necessary to make recommendations regarding the required IQ and protocol parameters for the majority of CT scanners to enable comparable IQ as well as radiation exposure for different sites but identical diagnostic questions.
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Affiliation(s)
- Andrea Steuwe
- Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Benedikt Kamp
- Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Saif Afat
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
| | - Alena Akinina
- Clinic and Outpatient Clinic for Radiology, University Hospital Halle (Saale), 06120 Halle, Germany
| | - Schekeb Aludin
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, 24105 Kiel, Germany
| | - Elif Gülsah Bas
- Department of Diagnostic and Interventional Radiology, University Hospital of Marburg, 35043 Marburg, Germany
| | - Josephine Berger
- Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany
| | - Evelyn Bohrer
- Department of Diagnostic and Interventional Radiology, University Hospital Giessen, Justus Liebig University, Klinikstr. 33, 35392 Giessen, Germany
| | - Alexander Brose
- Department of Diagnostic and Interventional Radiology, University Hospital Giessen, Justus Liebig University, Klinikstr. 33, 35392 Giessen, Germany
| | - Susanne Martina Büttner
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Constantin Ehrengut
- Department of Diagnostic and Interventional Radiology, University of Leipzig Medical Center, Liebigstraße 20, 04103 Leipzig, Germany
| | - Mirjam Gerwing
- Clinic of Radiology, University of Münster, 48149 Münster, Germany
| | - Sergio Grosu
- Department of Radiology, LMU University Hospital, LMU Munich, 81377 Munich, Germany
| | - Alexander Gussew
- Clinic and Outpatient Clinic for Radiology, University Hospital Halle (Saale), 06120 Halle, Germany
| | - Felix Güttler
- Department of Radiology, Jena University Hospital, Friedrich Schiller University, 07747 Jena, Germany
| | - Andreas Heinrich
- Department of Radiology, Jena University Hospital, Friedrich Schiller University, 07747 Jena, Germany
| | - Petra Jiraskova
- Institute of Diagnostic and Interventional Radiology, School of Medicine and Health, Technical University of Munich, 81675 Munich, Germany
| | - Christopher Kloth
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Jonathan Kottlors
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
| | | | - Christian Liska
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstraße 2, 86156 Augsburg, Germany
| | - Nora Lubina
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Stenglinstraße 2, 86156 Augsburg, Germany
| | - Mathias Manzke
- Institute of Diagnostic and Interventional Radiology, Paediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057 Rostock, Germany
| | - Felix G Meinel
- Institute of Diagnostic and Interventional Radiology, Paediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057 Rostock, Germany
| | - Hans-Jonas Meyer
- Department of Diagnostic and Interventional Radiology, University of Leipzig Medical Center, Liebigstraße 20, 04103 Leipzig, Germany
| | - Andreas Mittermeier
- Department of Radiology, LMU University Hospital, LMU Munich, 81377 Munich, Germany
| | - Thorsten Persigehl
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
| | - Lars-Patrick Schmill
- Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein Campus Kiel, 24105 Kiel, Germany
| | - Manuel Steinhardt
- Institute of Diagnostic and Interventional Radiology, School of Medicine and Health, Technical University of Munich, 81675 Munich, Germany
| | | | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Birte Valentin
- Department of Diagnostic and Interventional Radiology, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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Kazimierczak W, Kazimierczak N, Wilamowska J, Wojtowicz O, Nowak E, Serafin Z. Enhanced visualization in endoleak detection through iterative and AI-noise optimized spectral reconstructions. Sci Rep 2024; 14:3845. [PMID: 38360941 PMCID: PMC10869818 DOI: 10.1038/s41598-024-54502-1] [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: 11/30/2023] [Accepted: 02/13/2024] [Indexed: 02/17/2024] Open
Abstract
To assess the image quality parameters of dual-energy computed tomography angiography (DECTA) 40-, and 60 keV virtual monoenergetic images (VMIs) combined with deep learning-based image reconstruction model (DLM) and iterative reconstructions (IR). CT scans of 28 post EVAR patients were enrolled. The 60 s delayed phase of DECTA was evaluated. Objective [noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR)] and subjective (overall image quality and endoleak conspicuity - 3 blinded readers assessment) image quality analyses were performed. The following reconstructions were evaluated: VMI 40, 60 keV VMI; IR VMI 40, 60 keV; DLM VMI 40, 60 keV. The noise level of the DLM VMI images was approximately 50% lower than that of VMI reconstruction. The highest CNR and SNR values were measured in VMI DLM images. The mean CNR in endoleak in 40 keV was accounted for as 1.83 ± 1.2; 2.07 ± 2.02; 3.6 ± 3.26 in VMI, VMI IR, and VMI DLM, respectively. The DLM algorithm significantly reduced noise and increased lesion conspicuity, resulting in higher objective and subjective image quality compared to other reconstruction techniques. The application of DLM algorithms to low-energy VMIs significantly enhances the diagnostic value of DECTA in evaluating endoleaks. DLM reconstructions surpass traditional VMIs and IR in terms of image quality.
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Affiliation(s)
- Wojciech Kazimierczak
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland.
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009, Bydgoszcz, Poland.
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej - Curie 9, 85-094, Bydgoszcz, Poland.
| | - Natalia Kazimierczak
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009, Bydgoszcz, Poland
| | - Justyna Wilamowska
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej - Curie 9, 85-094, Bydgoszcz, Poland
| | - Olaf Wojtowicz
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej - Curie 9, 85-094, Bydgoszcz, Poland
| | - Ewa Nowak
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej - Curie 9, 85-094, Bydgoszcz, Poland
| | - Zbigniew Serafin
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej - Curie 9, 85-094, Bydgoszcz, Poland
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Kazimierczak W, Kazimierczak N, Serafin Z. Review of Clinical Applications of Dual-Energy CT in Patients after Endovascular Aortic Repair. J Clin Med 2023; 12:7766. [PMID: 38137834 PMCID: PMC10743598 DOI: 10.3390/jcm12247766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 12/08/2023] [Accepted: 12/16/2023] [Indexed: 12/24/2023] Open
Abstract
Abdominal aortic aneurysms (AAAs) are a significant cause of mortality in developed countries. Endovascular aneurysm repair (EVAR) is currently the leading treatment method for AAAs. Due to the high sensitivity and specificity of post-EVAR complication detection, CT angiography (CTA) is the reference method for imaging surveillance in patients after EVAR. Many studies have shown the advantages of dual-energy CT (DECT) over standard polyenergetic CTA in vascular applications. In this article, the authors briefly discuss the technical principles and summarize the current body of literature regarding dual-energy computed tomography angiography (DECTA) in patients after EVAR. The authors point out the most useful applications of DECTA in this group of patients and its advantages over conventional CTA. To conduct this review, a search was performed using the PubMed, Google Scholar, and Web of Science databases.
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Affiliation(s)
- Wojciech Kazimierczak
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067 Bydgoszcz, Poland
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009 Bydgoszcz, Poland
| | - Natalia Kazimierczak
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009 Bydgoszcz, Poland
| | - Zbigniew Serafin
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067 Bydgoszcz, Poland
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Hou KY, Yang CC. Investigating the Feasibility of Using DenseNet to Improve Coronary Calcification Detection in CT. Acad Radiol 2023; 30:1600-1613. [PMID: 36396585 DOI: 10.1016/j.acra.2022.10.018] [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: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/18/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Interscan reproducibility of coronary artery calcium (CAC) scoring can be improved by using a smaller slice thickness but at the cost of higher image noise. This study aimed to investigate the feasibility of using densely connected convolutional network (DenseNet) to reduce the image noise in CAC scans reconstructed with slice thickness < 3 mm for improving coronary calcification detection in CT. METHODS Phantom data acquired with QRM and CIRS phantoms were used for model training and testing, where the DenseNet model adopted in this work was a convolutional neural network (CNN) designed for super resolution recovery. After phantom study, the proposed method was evaluated in terms of its ability to improve calcification detection using patient data. The CNN input images (IMGinput) were CAC scans reconstructed with 0.5-, 1.0- and 1.5-mm slice thickness, while CNN label images were CAC scans reconstructed with 3-mm slice thickness (IMG3mm). Region of interest (ROI) analysis was carried out on IMG3mm, IMGinput and CNN output images (IMGoutput). Two-sample t test was used to compare the difference in Hounsfield Unit (HU) values within ROI between IMG3mm and IMGoutput. RESULTS For the calcifications in QRM phantoms, no statistically significant difference was found when comparing the HU values of 400- and 800-HA calcifications identified on IMG3mm to those on IMGoutput with slice thickness of 0.5, 1.0 or 1.5 mm. On the other hand, statistically significant difference was found when comparing the HU values of 200-HA calcifications identified on IMG3mm to those on IMGoutput with a slice thickness of 0.5 and 1.0 mm. Meanwhile, no statistically significant difference was found when comparing the HU values of 200-HA calcifications identified on IMG3mm to those on IMGoutput with a slice thickness of 1.5 mm. As for the rod inserts in CIRS phantoms simulating 9 different tissue types in human body, there was no statistically significant difference between IMG3mm and IMGoutput with slice thickness of 1.5 mm, and all the p values were larger than 0.10. With regards to patient study, more calcification pixels were detected on IMGoutput with a slice thickness of 1.5 mm than on IMG3mm, so calcifications were more clear on the denoised images. CONCLUSION According to our results, the CNN-based denoising method could reduce statistical noise in IMGinput with a slice thickness of 1.5 mm without causing significant texture change or variation in HU values. The proposed method could improve cardiovascular risk prediction by detecting small and soft calcifications that are barely identified on 3-mm slice images used in conventional CAC scans.
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Affiliation(s)
- Kuei-Yuan Hou
- Department of Radiology, Cathay General Hospital, Taipei, Taiwan, ROC (K.Y.H); Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, No.100, Shin-Chuan 1st Road, Sanmin Dist., Kaohsiung, Taiwan, 80708, ROC (C.C.Y.); Department of Medical Research, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan, ROC (C.C.Y.); Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC (K.Y.H)
| | - Ching-Ching Yang
- Department of Radiology, Cathay General Hospital, Taipei, Taiwan, ROC (K.Y.H); Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, No.100, Shin-Chuan 1st Road, Sanmin Dist., Kaohsiung, Taiwan, 80708, ROC (C.C.Y.); Department of Medical Research, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan, ROC (C.C.Y.); Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC (K.Y.H).
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Berbís MA, Paulano Godino F, Royuela del Val J, Alcalá Mata L, Luna A. Clinical impact of artificial intelligence-based solutions on imaging of the pancreas and liver. World J Gastroenterol 2023; 29:1427-1445. [PMID: 36998424 PMCID: PMC10044858 DOI: 10.3748/wjg.v29.i9.1427] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/13/2023] [Accepted: 02/27/2023] [Indexed: 03/07/2023] Open
Abstract
Artificial intelligence (AI) has experienced substantial progress over the last ten years in many fields of application, including healthcare. In hepatology and pancreatology, major attention to date has been paid to its application to the assisted or even automated interpretation of radiological images, where AI can generate accurate and reproducible imaging diagnosis, reducing the physicians’ workload. AI can provide automatic or semi-automatic segmentation and registration of the liver and pancreatic glands and lesions. Furthermore, using radiomics, AI can introduce new quantitative information which is not visible to the human eye to radiological reports. AI has been applied in the detection and characterization of focal lesions and diffuse diseases of the liver and pancreas, such as neoplasms, chronic hepatic disease, or acute or chronic pancreatitis, among others. These solutions have been applied to different imaging techniques commonly used to diagnose liver and pancreatic diseases, such as ultrasound, endoscopic ultrasonography, computerized tomography (CT), magnetic resonance imaging, and positron emission tomography/CT. However, AI is also applied in this context to many other relevant steps involved in a comprehensive clinical scenario to manage a gastroenterological patient. AI can also be applied to choose the most convenient test prescription, to improve image quality or accelerate its acquisition, and to predict patient prognosis and treatment response. In this review, we summarize the current evidence on the application of AI to hepatic and pancreatic radiology, not only in regard to the interpretation of images, but also to all the steps involved in the radiological workflow in a broader sense. Lastly, we discuss the challenges and future directions of the clinical application of AI methods.
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Affiliation(s)
- M Alvaro Berbís
- Department of Radiology, HT Médica, San Juan de Dios Hospital, Córdoba 14960, Spain
- Faculty of Medicine, Autonomous University of Madrid, Madrid 28049, Spain
| | | | | | - Lidia Alcalá Mata
- Department of Radiology, HT Médica, Clínica las Nieves, Jaén 23007, Spain
| | - Antonio Luna
- Department of Radiology, HT Médica, Clínica las Nieves, Jaén 23007, Spain
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Armstrong AC, Cerci R, Matheson MB, Magalhães T, Kishi S, Brinker J, Clouse ME, Rochitte CE, Cox C, Lima JAC, Arbab-Zadeh A. Predicting Significant Coronary Obstruction in a Population with Suspected Coronary Disease and Absence of Coronary Calcium: CORE-64 / CORE320 Studies. Arq Bras Cardiol 2023; 120:e20220183. [PMID: 36946854 DOI: 10.36660/abc.20220183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 11/16/2022] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND Coronary artery calcium (CAC) scanning can be performed using non-contrast computed tomography to predict cardiovascular events, but has less value for risk stratification in symptomatic patients. OBJECTIVE To identify and validate predictors of significant coronary obstruction (SCO) in symptomatic patients without coronary artery calcification. METHODS A total of 4,258 participants were screened from the CORE64 and CORE320 studies that enrolled patients referred for invasive angiography, and from the Quanta Registry that included patients referred for coronary computed tomography angiography (CTA). Logistic regression models evaluated associations between cardiovascular risk factors, CAC, and SCO. An algorithm to assess the risk of SCO was proposed for patients without CAC. Significance level of 5% was used in the analyses. RESULTS Of the 509 participants of the CORE study, 117 (23%) had zero coronary calcium score; 13 (11%) patients without CAC had SCO. Zero calcium score was related to younger age, female gender, lower body mass index, no diabetes, and no dyslipidemia. Being a current smoker increased ~3.5 fold the probability of SCO and other CV risk factors were not significantly associated. Considering the clinical findings, an algorithm to further stratify zero calcium score patients was proposed and had a limited performance in the validation cohort (AUC 58; 95%CI 43, 72). CONCLUSION A lower cardiovascular risk profile is associated with zero calcium score in a setting of high-risk patients. Smoking is the strongest predictor of SCO in patients without CAC.
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Affiliation(s)
- Anderson C Armstrong
- Universidade Federal do Vale do São Francisco , Petrolina , PE - Brasil
- Johns Hopkins Hospital , Baltimore - EUA
| | | | | | | | | | | | | | - Carlos E Rochitte
- Instituto do Coração do Hospital das Clínicas da Universidade de São Paulo , São Paulo , SP - Brasil
| | - Christopher Cox
- Johns Hopkins Bloomberg School of Public Health , Baltimore - EUA
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Nates R, Arazi M, Grosman-Rimon L, Israel R, Gohari J, Sternik L, Kachel E. The routine use of preoperative non-contrast chest computerized tomography and carotid arteries Doppler prior to cardiac surgery. J Cardiothorac Surg 2022; 17:178. [PMID: 35871007 PMCID: PMC9308923 DOI: 10.1186/s13019-022-01927-2] [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: 04/20/2021] [Accepted: 07/09/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction There is no consensus as to which patients should undergo Non-Contrast Chest Computerized Tomography (NCCCT) and carotid arteries Doppler (CD) prior to cardiac surgery. The objective of this study was to examine whether preoperative imaging modalities provide clinical benefits and a change in surgical strategy. Methods We routinely performed NCCCT and CD in all non-urgent cardiac surgery patients. Major NCCCT/CD findings related to cardiovascular findings (aortic calcification/atherosclerosis, carotid artery plaque/stenosis), or other incidental findings (lung kidney, thyroid, adrenal, gastrointestinal sites etc.) were documented. The results were divided into 3 categories: (A) findings requiring both changes in surgical strategy and post-operative evaluation/treatment; (B) findings requiring changes in surgical strategy, but not requiring a specific post-operative evaluation/treatment; (C) findings not requiring changes in surgical strategy but requiring post-operative evaluation/treatment. Results In this cohort, 93 (18.6%) out of 500 patients had significant cardiac and extra-cardiac findings on NCCCT and/or CD. Among the 93 patients with significant findings, 33.33% (31 patients, 6.2% of all patients) were in group A, 7.5% (7 patients, 1.4% of all patients) were in group B, and 59.14% (55 patients, 11% of all patients) were in group C. Change in surgical strategies included, for example, switching from planned on-pump Coronary Artery Bypass Graft surgery (CABG) to off-pump CABG and performing additional procedures to the originally planned heart surgery. Conclusion Routine preoperative NCCCT and CD evaluation in all non-urgent cardiac surgical patients is an effective measure for uncovering cardiac and extra-cardiac findings prior to surgery.
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10
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Lee HJ, Kim SK, Lee JW, Im SA, Chung NG, Cho B. Quantitative CT lung densitometry as an obstructive marker for the diagnosis of bronchiolitis obliterans in children. PLoS One 2022; 17:e0271135. [PMID: 35797398 PMCID: PMC9262182 DOI: 10.1371/journal.pone.0271135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/23/2022] [Indexed: 11/17/2022] Open
Abstract
The purpose of this study is to evaluate the quantitative diagnostic performance of computed tomography (CT) densitometry in pediatric patients with bronchiolitis obliterans (BO). We measured the mean lung density (MLD) and represented the difference of MLD in inspiratory and expiratory phases (MLDD), the ratio of the MLD (E/I MLD), and the relative volume percentage of lung density at 50-Hounsfield unit (HU) interval threshold (E600 to E950). We calculated the sensitivity, specificity, and diagnostic accuracy of the lung density indices for the diagnosis of BO. A total of 81 patients, including 51 patients with BO and 30 controls, were included in this study. In the BO patients, expiratory (EXP) MLD and MLDD were significantly lower, and E/I MLD and expiratory low attenuation areas below the threshold of −850 HU to −950 HU (E850, E900, and E950) were statistically significantly higher than controls. Multivariate logistic regression analysis showed that MLDD (odds ratio [OR] = 0.98, p < .001), E/I MLD (OR = 1.39, p < .001), and E850 to E950 were significant densitometry parameters for BO diagnosis. In a receiver-operating characteristic analysis, E900 (cutoff, 1.4%; AUC = 0.920), E/I MLD (cutoff, 0.87; AUC = 0.887), and MLDD (cutoff, 109 HU; AUC = 0.867) showed high accuracy for the diagnosis of BO. In conclusion, the lung CT densitometry can serve as a quantitative marker providing additional indications of expiratory airflow limitation in pediatric patients with BO.
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Affiliation(s)
- Hye Jin Lee
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Seong Koo Kim
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jae Wook Lee
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Soo Ah Im
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- * E-mail:
| | - Nack-Gyun Chung
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Bin Cho
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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11
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Low-Dose High-Resolution Photon-Counting CT of the Lung: Radiation Dose and Image Quality in the Clinical Routine. Diagnostics (Basel) 2022; 12:diagnostics12061441. [PMID: 35741251 PMCID: PMC9221815 DOI: 10.3390/diagnostics12061441] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/04/2022] [Accepted: 06/07/2022] [Indexed: 01/09/2023] Open
Abstract
This study aims to investigate the qualitative and quantitative image quality of low-dose high-resolution (LD-HR) lung CT scans acquired with the first clinical approved photon counting CT (PCCT) scanner. Furthermore, the radiation dose used by the PCCT is compared to a conventional CT scanner with an energy-integrating detector system (EID-CT). Twenty-nine patients who underwent a LD-HR chest CT scan with dual-source PCCT and had previously undergone a LD-HR chest CT with a standard EID-CT scanner were retrospectively included in this study. Images of the whole lung as well as enlarged image sections displaying a specific finding (lesion) were evaluated in terms of overall image quality, image sharpness and image noise by three senior radiologists using a 5-point Likert scale. The PCCT images were reconstructed with and without a quantum iterative reconstruction algorithm (PCCT QIR+/−). Noise and signal-to-noise (SNR) were measured and the effective radiation dose was calculated. Overall, image quality and image sharpness were rated best in PCCT (QIR+) images. A significant difference was seen particularly in image sections of PCCT (QIR+) images compared to EID-CT images (p < 0.005). Image noise of PCCT (QIR+) images was significantly lower compared to EID-CT images in image sections (p = 0.005). In contrast, noise was lowest on EID-CT images (p < 0.001). The PCCT used significantly less radiation dose compared to the EID-CT (p < 0.001). In conclusion, LD-HR PCCT scans of the lung provide better image quality while using significantly less radiation dose compared to EID-CT scans.
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12
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High-strength deep learning image reconstruction in coronary CT angiography at 70-kVp tube voltage significantly improves image quality and reduces both radiation and contrast doses. Eur Radiol 2022; 32:2912-2920. [DOI: 10.1007/s00330-021-08424-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/17/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022]
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13
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Franck C, Snoeckx A, Spinhoven M, El Addouli H, Nicolay S, Van Hoyweghen A, Deak P, Zanca F. PULMONARY NODULE DETECTION IN CHEST CT USING A DEEP LEARNING-BASED RECONSTRUCTION ALGORITHM. RADIATION PROTECTION DOSIMETRY 2021; 195:158-163. [PMID: 33723584 DOI: 10.1093/rpd/ncab025] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/14/2021] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
This study's aim was to assess whether deep learning image reconstruction (DLIR) techniques are non-inferior to ASIR-V for the clinical task of pulmonary nodule detection in chest computed tomography. Up to 6 (range 3-6, mean 4.2) artificial lung nodules (diameter: 3, 5, 8 mm; density: -800, -630, +100 HU) were inserted at different locations in the Kyoto Kagaku Lungman phantom. In total, 16 configurations (10 abnormal, 6 normal) were scanned at 7.6, 3, 1.6 and 0.38 mGy CTDIvol (respectively 0, 60, 80 and 95% dose reduction). Images were reconstructed using 50% ASIR-V and a deep learning-based algorithm with low (DL-L), medium (DL-M) and high (DL-H) strength. Four chest radiologists evaluated 256 series by locating and scoring nodules on a five-point scale. No statistically significant difference was found among the reconstruction algorithms (p = 0.987, average across readers AUC: 0.555, 0.561, 0.557, 0.558 for ASIR-V, DL-L, DL-M, DL-H).
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Affiliation(s)
- C Franck
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - A Snoeckx
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - M Spinhoven
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - H El Addouli
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - S Nicolay
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - A Van Hoyweghen
- Department of Radiology, University Hospital Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
- mVISION, Faculty of Medicine and Health Sciences, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - P Deak
- GE Healthcare, Glattbrugg, Switzerland
| | - F Zanca
- Palindromo Consulting, Leuven, Belgium
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Best Practices: Imaging Strategies for Reduced-Dose Chest CT in the Management of Cystic Fibrosis-Related Lung Disease. AJR Am J Roentgenol 2021; 217:304-313. [PMID: 34076456 DOI: 10.2214/ajr.19.22694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE. Cystic fibrosis (CF) is a multisystemic life-limiting disorder. The leading cause of morbidity in CF is chronic pulmonary disease. Chest CT is the reference standard for detection of bronchiectasis. Cumulative ionizing radiation limits the use of CT, particularly as treatments improve and life expectancy increases. The purpose of this article is to summarize the evidence on low-dose chest CT and its effect on image quality to determine best practices for imaging in CF. CONCLUSION. Low-dose chest CT is technically feasible, reduces dose, and renders satisfactory image quality. There are few comparison studies of low-dose chest CT and standard chest CT in CF; however, evidence suggests equivalent diagnostic capability. Low-dose chest CT with iterative reconstructive algorithms appears superior to chest radiography and equivalent to standard CT and has potential for early detection of bronchiectasis and infective exacerbations, because clinically significant abnormalities can develop in patients who do not have symptoms. Infection and inflammation remain the primary causes of morbidity requiring early intervention. Research gaps include the benefits of replacing chest radiography with low-dose chest CT in terms of improved diagnostic yield, clinical decision making, and patient outcomes. Longitudinal clinical studies comparing CT with MRI for the monitoring of CF lung disease may better establish the complementary strengths of these imaging modalities.
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15
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Novellis P, Cominesi SR, Rossetti F, Mondoni M, Gregorc V, Veronesi G. Lung cancer screening: who pays? Who receives? The European perspectives. Transl Lung Cancer Res 2021; 10:2395-2406. [PMID: 34164287 PMCID: PMC8182705 DOI: 10.21037/tlcr-20-677] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lung cancer is the leading cause of cancer-related death worldwide, and its early detection is critical to achieving a curative treatment and to reducing mortality. Low-dose computed tomography (LDCT) is a highly sensitive technique for detecting noninvasive small lung tumors in high-risk populations. We here analyze the current status of lung cancer screening (LCS) from a European point of view. With economic burden of health care in most European countries resting on the state, it is important to reduce costs of screening and improve its effectiveness. Current cost-effectiveness analyses on LCS have indicated a favorable economic profile. The most recently published analysis reported an incremental cost-effectiveness ratio (ICER) of €3,297 per 1 life-year gained adjusted for the quality of life (QALY) and €2,944 per life-year gained, demonstrating a 90% probability of ICER being below €15,000 and a 98.1% probability of being below €25,000. Different risk models have been used to identify the target population; among these, the PLCOM2012 in particular allows for the selection of the population to be screened with high sensitivity. Risk models should also be employed to define screening intervals, which can reduce the general number of LDCT scans after the baseline round. Future perspectives of screening in a European scenario are related to the will of the policy makers to implement policy on a large scale and to improve the effectiveness of a broad screening of smoking-related disease, including cardiovascular prevention, by measuring coronary calcium score on LDCT. The employment of artificial intelligence (AI) in imaging interpretation, the use of liquid biopsies for the characterization of CT-detected undetermined nodules, and less invasive, personalized surgical treatments, will improve the effectiveness of LCS.
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Affiliation(s)
- Pierluigi Novellis
- Division of Thoracic Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Francesca Rossetti
- Division of Thoracic Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Michele Mondoni
- Department of Health Sciences, University of Milan, Respiratory Unit, ASST Santi Paolo e Carlo, Milan, Italy
| | - Vanesa Gregorc
- Department of Medical Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giulia Veronesi
- Division of Thoracic Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Milan, Italy
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16
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Alexander BD, Lamoth F, Heussel CP, Prokop CS, Desai SR, Morrissey CO, Baddley JW. Guidance on Imaging for Invasive Pulmonary Aspergillosis and Mucormycosis: From the Imaging Working Group for the Revision and Update of the Consensus Definitions of Fungal Disease from the EORTC/MSGERC. Clin Infect Dis 2021; 72:S79-S88. [PMID: 33709131 DOI: 10.1093/cid/ciaa1855] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Clinical imaging in suspected invasive fungal disease (IFD) has a significant role in early detection of disease and helps direct further testing and treatment. Revised definitions of IFD from the EORTC/MSGERC were recently published and provide clarity on the role of imaging for the definition of IFD. Here, we provide evidence to support these revised diagnostic guidelines. METHODS We reviewed data on imaging modalities and techniques used to characterize IFDs. RESULTS Volumetric high-resolution computed tomography (CT) is the method of choice for lung imaging. Although no CT radiologic pattern is pathognomonic of IFD, the halo sign, in the appropriate clinical setting, is highly suggestive of invasive pulmonary aspergillosis (IPA) and associated with specific stages of the disease. The ACS is not specific for IFD and occurs in the later stages of infection. By contrast, the reversed halo sign and the hypodense sign are typical of pulmonary mucormycosis but occur less frequently. In noncancer populations, both invasive pulmonary aspergillosis and mucormycosis are associated with "atypical" nonnodular presentations, including consolidation and ground-glass opacities. CONCLUSIONS A uniform definition of IFD could improve the quality of clinical studies and aid in differentiating IFD from other pathology in clinical practice. Radiologic assessment of the lung is an important component of the diagnostic work-up and management of IFD. Periodic review of imaging studies that characterize findings in patients with IFD will inform future diagnostic guidelines.
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Affiliation(s)
- Barbara D Alexander
- Department of Medicine, Division of Infectious Diseases, Duke University, Durham, North Carolina, USA
| | - Frédéric Lamoth
- Service of Infectious Diseases, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.,Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Claus Peter Heussel
- Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik gGmbH, Heidelberg, Germany.,Translational Lung Research Centre Heidelberg, Member of the German Centre for Lung Research.,Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg, Germany
| | | | - Sujal R Desai
- Department of Radiology, Royal Brompton and Harefield National Health Service Foundation Trust, London and National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - C Orla Morrissey
- Department of Infectious Diseases, Alfred Health and Monash University, Melbourne, Australia
| | - John W Baddley
- Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, Maryland, USA
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17
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Steuwe A, Weber M, Bethge OT, Rademacher C, Boschheidgen M, Sawicki LM, Antoch G, Aissa J. Influence of a novel deep-learning based reconstruction software on the objective and subjective image quality in low-dose abdominal computed tomography. Br J Radiol 2021; 94:20200677. [PMID: 33095654 DOI: 10.1259/bjr.20200677] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Modern reconstruction and post-processing software aims at reducing image noise in CT images, potentially allowing for a reduction of the employed radiation exposure. This study aimed at assessing the influence of a novel deep-learning based software on the subjective and objective image quality compared to two traditional methods [filtered back-projection (FBP), iterative reconstruction (IR)]. METHODS In this institutional review board-approved retrospective study, abdominal low-dose CT images of 27 patients (mean age 38 ± 12 years, volumetric CT dose index 2.9 ± 1.8 mGy) were reconstructed with IR, FBP and, furthermore, post-processed using a novel software. For the three reconstructions, qualitative and quantitative image quality was evaluated by means of CT numbers, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in six different ROIs. Additionally, the reconstructions were compared using SNR, peak SNR, root mean square error and mean absolute error to assess structural differences. RESULTS On average, CT numbers varied within 1 Hounsfield unit (HU) for the three assessed methods in the assessed ROIs. In soft tissue, image noise was up to 42% lower compared to FBP and up to 27% lower to IR when applying the novel software. Consequently, SNR and CNR were highest with the novel software. For both IR and the novel software, subjective image quality was equal but higher than the image quality of FBP-images. CONCLUSION The assessed software reduces image noise while maintaining image information, even in comparison to IR, allowing for a potential dose reduction of approximately 20% in abdominal CT imaging. ADVANCES IN KNOWLEDGE The assessed software reduces image noise by up to 27% compared to IR and 48% compared to FBP while maintaining the image information.The reduced image noise allows for a potential dose reduction of approximately 20% in abdominal imaging.
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Affiliation(s)
- Andrea Steuwe
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Marie Weber
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Oliver Thomas Bethge
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Christin Rademacher
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Matthias Boschheidgen
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Lino Morris Sawicki
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
| | - Joel Aissa
- Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany
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Abstract
BACKGROUND Computed tomography (CT) is a central modality in modern radiology contributing to diagnostic medicine in almost every medical subspecialty, but particularly in emergency services. To solve the inverse problem of reconstructing anatomical slice images from the raw output the scanner measures, several methods have been developed, with filtered back projection (FBP) and iterative reconstruction (IR) subsequently providing criterion standards. Currently there are new approaches to reconstruction in the field of artificial intelligence utilizing the upcoming possibilities of machine learning (ML), or more specifically, deep learning (DL). METHOD This review covers the principles of present CT image reconstruction as well as the basic concepts of DL and its implementation in reconstruction. Subsequently commercially available algorithms and current limitations are being discussed. RESULTS AND CONCLUSION DL is an ML method that utilizes a trained artificial neural network to solve specific problems. Currently two vendors are providing DL image reconstruction algorithms for the clinical routine. For these algorithms, a decrease in image noise and an increase in overall image quality that could potentially facilitate the diagnostic confidence in lesion conspicuity or may translate to dose reduction for given clinical tasks have been shown. One study showed equal diagnostic accuracy in the detection of coronary artery stenosis for DL reconstructed images compared to IR at higher image quality levels. Consequently, a lot more research is necessary and should aim at diagnostic superiority in the clinical context covering a broadness of pathologies to demonstrate the reliability of such DL approaches. KEY POINTS · Following iterative reconstruction, there is a new approach to CT image reconstruction in the clinical routine using deep learning (DL) as a method of artificial intelligence.. · DL image reconstruction algorithms decrease image noise, improve image quality, and have potential to reduce radiation dose.. · Diagnostic superiority in the clinical context should be demonstrated in future trials.. CITATION FORMAT · Arndt C, Güttler F, Heinrich A et al. Deep Learning CT Image Reconstruction in Clinical Practice. Fortschr Röntgenstr 2021; 193: 252 - 261.
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19
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Fletcher JG, Levin DL, Sykes AMG, Lindell RM, White DB, Kuzo RS, Suresh V, Yu L, Leng S, Holmes DR, Inoue A, Johnson MP, Carter RE, McCollough CH. Observer Performance for Detection of Pulmonary Nodules at Chest CT over a Large Range of Radiation Dose Levels. Radiology 2020; 297:699-707. [PMID: 32990514 DOI: 10.1148/radiol.2020200969] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background There is a wide variation in radiation dose levels that can be used with chest CT in order to detect indeterminate pulmonary nodules. Purpose To compare the performance of lower-radiation-dose chest CT with that of routine dose in the detection of indeterminate pulmonary nodules 5 mm or greater. Materials and Methods In this retrospective study, CT projection data from 83 routine-dose chest CT examinations performed in 83 patients (120 kV, 70 quality reference mAs [QRM]) were collected between November 2013 and April 2014. Reference indeterminate pulmonary nodules were identified by two nonreader thoracic radiologists. By using validated noise insertion, five lower-dose data sets were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR; 30 QRM with FBP, 10 QRM with IR, 5 QRM with FBP, 5 QRM with IR, and 2.5 QRM with IR). Three thoracic radiologists circled pulmonary nodules, rating confidence that the nodule was a 5-mm-or-greater indeterminate pulmonary nodule, and graded image quality. Analysis was performed on a per-nodule basis by using jackknife alternative free-response receiver operating characteristic figure of merit (FOM) and noninferiority limit of -0.10. Results There were 66 indeterminate pulmonary nodules (mean size, 8.6 mm ± 3.4 [standard deviation]; 21 part-solid nodules) in 42 patients (mean age, 51 years ± 17; 21 men and 21 women). Compared with the FOM for routine-dose CT (size-specific dose estimate, 6.5 mGy ± 1.8; FOM, 0.86 [95% confidence interval: 0.80, 0.91]), FOM was noninferior for all lower-dose configurations except for 2.5 QRM with IR. The sensitivity for subsolid nodules at 70 QRM was 60% (range, 48%-72%) and was significantly worse at a dose of 5 QRM and lower, whether or not IR was used (P < .05). Diagnostic image quality decreased with decreasing dose (P < .001) and was better with IR at 5 QRM (P < .05). Conclusion CT images reconstructed at dose levels down to 10 quality reference mAs (size-specific dose estimate, 0.9 mGy) had noninferior performance compared with routine dose in depicting pulmonary nodules. Iterative reconstruction improved subjective image quality but not performance at low dose levels. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by White and Kazerooni in this issue.
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Affiliation(s)
- Joel G Fletcher
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - David L Levin
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Anne-Marie G Sykes
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Rebecca M Lindell
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Darin B White
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Ronald S Kuzo
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Vighnesh Suresh
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Lifeng Yu
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Shuai Leng
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - David R Holmes
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Akitoshi Inoue
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Matthew P Johnson
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Rickey E Carter
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
| | - Cynthia H McCollough
- From the Department of Radiology (J.G.F., D.L.L., A.M.G.S., R.M.L., D.B.W., R.S.K., V.S., L.Y., S.L., A.I., C.H.M.), Department of Physiology and Biomedical Engineering (D.R.H.), and Department of Health Science Research (M.P.J.), Mayo Clinic, 200 First St SW, Rochester, MN 55905; and Department of Health Science Research, Mayo Clinic, Jacksonville, Fla (R.E.C.)
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Jensen K, Hagemo G, Tingberg A, Steinfeldt-Reisse C, Mynarek GK, Rivero RJ, Fosse E, Martinsen AC. Evaluation of Image Quality for 7 Iterative Reconstruction Algorithms in Chest Computed Tomography Imaging: A Phantom Study. J Comput Assist Tomogr 2020; 44:673-680. [PMID: 32936576 DOI: 10.1097/rct.0000000000001037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES This study aimed to evaluate the image quality of 7 iterative reconstruction (IR) algorithms in comparison to filtered back-projection (FBP) algorithm. METHODS An anthropomorphic chest phantom was scanned on 4 computed tomography scanners and reconstructed with FBP and IR algorithms. Image quality of anatomical details-large/medium-sized pulmonary vessels, small pulmonary vessels, thoracic wall, and small and large lesions-was scored. Furthermore, general impression of noise, image contrast, and artifacts were evaluated. Visual grading regression was used to analyze the data. Standard deviations were measured, and the noise power spectrum was calculated. RESULTS Iterative reconstruction algorithms showed significantly better results when compared with FBP for these criteria (regression coefficients/P values in parentheses): vessels (FIRST: -1.8/0.05, AIDR Enhanced: <-2.3/0.01, Veo: <-0.1/0.03, ADMIRE: <-2.1/0.04), lesions (FIRST: <-2.6/0.01, AIDR Enhanced: <-1.9/0.03, IMR1: <-2.7/0.01, Veo: <-2.4/0.02, ADMIRE: -2.3/0.02), image noise (FIRST: <-3.2/0.004, AIDR Enhanced: <-3.5/0.002, IMR1: <-6.1/0.001, iDose: <-2.3/0.02, Veo: <-3.4/0.002, ADMIRE: <-3.5/0.02), image contrast (FIRST: -2.3/0.01, AIDR Enhanced: -2.5/0.01, IMR1: -3.7/0.001, iDose: -2.1/0.02), and artifacts (FIRST: <-3.8/0.004, AIDR Enhanced: <-2.7/0.02, IMR1: <-2.6/0.02, iDose: -2.1/0.04, Veo: -2.6/0.02). The iDose algorithm was the only IR algorithm that maintained the noise frequencies. CONCLUSIONS Iterative reconstruction algorithms performed differently on all evaluated criteria, showing the importance of careful implementation of algorithms for diagnostic purposes.
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Affiliation(s)
| | - Guro Hagemo
- Department of Radiology and Nuclear Medicine, Radiumhospitalet, Oslo University Hospital, Oslo, Norway
| | - Anders Tingberg
- Department of Medical Radiation Physics, Lund University, Skåne University Hospital, Malmö, Sweden
| | | | - Georg Karl Mynarek
- Department of Radiology and Nuclear Medicine, Rikshospitalet, Oslo University Hospital
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Task-based characterization of a deep learning image reconstruction and comparison with filtered back-projection and a partial model-based iterative reconstruction in abdominal CT: A phantom study. Phys Med 2020; 76:28-37. [DOI: 10.1016/j.ejmp.2020.06.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/28/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022] Open
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Renz DM, Dohna M, Böttcher J, Kaireit TF, Pfeil A, Streitparth F, Vogel-Claussen J. Magnetresonanztomographie der Lunge bei zystischer Fibrose. Monatsschr Kinderheilkd 2020. [DOI: 10.1007/s00112-020-00890-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sakane H, Ishida M, Shi L, Fukumoto W, Sakai C, Miyata Y, Ishida T, Akita T, Okada M, Awai K, Tashiro S. Biological Effects of Low-Dose Chest CT on Chromosomal DNA. Radiology 2020; 295:439-445. [PMID: 32154776 DOI: 10.1148/radiol.2020190389] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Background Although the National Lung Screening Trial reported a significant reduction in lung cancer mortality when low-dose (LD) CT chest examinations are used for a diagnosis, their biologic effects from radiation exposure remain unclear. Purpose To compare LD CT and standard-dose (SD) CT for DNA double-strand breaks and chromosome aberrations (CAs) in peripheral blood lymphocytes. Materials and Methods Between March 2016 and June 2018, 209 participants who were referred to a respiratory surgery department for chest CT studies were prospectively enrolled in this study. Individuals were excluded if they had undergone radiography examinations within the last 3 days or had undergone chemotherapy or radiation therapy. Peripheral blood samples were obtained before and 15 minutes after CT. The number of γ-H2AX foci and unstable CAs in lymphocytes was quantified by immunofluorescent staining of γ-H2AX and by fluorescence in situ hybridization by using peptide nucleic acid probes for centromeres and telomeres, respectively. The Wilcoxon signed rank test was used for statistical analysis. Bonferroni correction was applied for multiple comparisons. Results Of the 209 participants (105 women, 104 men; mean age, 67.0 years ± 11.3 [standard deviation]), 107 underwent chest LD CT and 102 underwent chest SD CT. Sex distribution, age, and body size metrics were similar between the two groups. The median effective dose of LD CT and SD CT was 1.5 and 5.0 mSv, respectively. The number of double-strand breaks and CAs increased after a SD CT examination (γ-H2AX, P < .001; CAs, P = .003); the number of double-strand breaks and CAs before and after LD CT was not different (γ-H2AX, P = .45; CAs, P = .69). Conclusion No effect of low-dose CT on human DNA was detected. In the same setting, DNA double-strand breaks and chromosome aberrations increased after standard-dose CT. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Brenner in this issue.
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Affiliation(s)
- Hiroaki Sakane
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Mari Ishida
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Lin Shi
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Wataru Fukumoto
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Chiemi Sakai
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Yoshihiro Miyata
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Takafumi Ishida
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Tomoyuki Akita
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Morihito Okada
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Kazuo Awai
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
| | - Satoshi Tashiro
- From the Department of Diagnostic Radiology, Graduate School of Biomedical Health Sciences, Hiroshima University, Hiroshima, Japan (H.S., W.F., K.A.); Department of Cardiovascular Physiology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (M.I., C.S.); Departments of Cellular Biology (L.S., S.T.) and Surgical Oncology (Y.M., M.O.), Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8553, Japan; Department of Epidemiology, Infectious Disease Control and Prevention, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan (T.A.); and Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima, Japan (T.I.)
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Steuwe A, Thomas C, Kraus B, Bethge OT, Aissa J, Klosterkemper Y, Antoch G, Boos J. Development of size-specific institutional diagnostic reference levels for computed tomography protocols in neck imaging. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2020; 40:68-82. [PMID: 31604340 DOI: 10.1088/1361-6498/ab4d00] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE To develop size-specific institutional diagnostic reference levels (DRLs) for computed tomography (CT) protocols used in neck CT imaging (cervical spine CT, cervical CT angiography (CTA) and cervical staging CT) and to compare institutional to national DRLs. MATERIALS AND METHODS Cervical CT examinations (spine, n = 609; CTA, n = 505 and staging CT, n = 184) performed between 01/2016 and 06/2017 were included in this retrospective study. For each region and examination, the volumetric CT dose index (CTDIvol) and dose-length product (DLP) were determined and binned into size bins according to patient water-equivalent diameter (dw). Linear regression analysis was performed to calculate size-specific institutional DRLs for CTDIvol and DLP, applying the 75th percentile as the upper limit for institutional DRLs. The mean institutional CTDIvol and DLP were compared to national DRLs (CTDIvol 20 mGy for cervical spine CT (DLP 300 mGycm) and cervical CTA (DLP 600 mGycm), and CTDIvol 15 mGy for cervical staging CT (DLP 330 mGycm)). RESULTS The mean CTDIvol and DLP (±standard deviation) were 15.2 ± 4.1 mGy and 181.5 ± 88.3 mGycm for cervical spine CT; 8.1 ± 4.3 mGy and 280.2 ± 164.3 mGycm for cervical CTA; 8.6 ± 1.9 mGy and 162.8 ± 85.0 mGycm for cervical staging CT. For all CT protocols, there was a linear increase in CTDIvol and DLP with increasing dw. For the CTDIvol, size-specific institutional DRLs increased with dw from 14 to 29 mGy for cervical spine CT, from 5 to 17 mGy for cervical CTA and from 8 to 13 mGy for cervical staging CT. For the DLP, size-specific institutional DRLs increased with dw from 130 to 510 mGycm for cervical spine CT, from 140 to 640 mGycm for cervical CTA and from 140 to 320 mGycm for cervical staging CT. Institutional DRLs were lower than national DRLs by 81% and 67% for cervical spine CT (dw = 17.8 cm), 43% and 51% for cervical CTA (dw = 19.5 cm) and 59% and 53% for cervical staging CT (dw = 18.8 cm) for CTDIvol and DLP, respectively. CONCLUSION Size-specific institutional DRLs were generated for neck CT examinations. The mean institutional CTDIvol and DLP values were well below national DRLs.
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Affiliation(s)
- Andrea Steuwe
- University Düsseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Düsseldorf, Germany
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Mohammadinejad P, Ehman EC, Vasconcelos RN, Venkatesh SK, Hough DM, Lowe R, Lee YS, Nehra A, Dirks S, Holmes DR, Carter RE, Schmidt B, Halaweish AF, McCollough CH, Fletcher JG. Prior iterative reconstruction (PIR) to lower radiation dose and preserve radiologist performance for multiphase liver CT: a multi-reader pilot study. Abdom Radiol (NY) 2020; 45:45-54. [PMID: 31705250 DOI: 10.1007/s00261-019-02280-0] [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] [Indexed: 12/15/2022]
Abstract
PURPOSE Prior iterative reconstruction (PIR) spatially registers CT image data from multiple phases of enhancement to reduce image noise. We evaluated PIR in contrast-enhanced multiphase liver CT. METHODS Patients with archived projection CT data with proven malignant or benign liver lesions, or without lesions, by reference criteria were included. Lower-dose PIR images were reconstructed using validated noise insertion from multiphase CT exams (50% dose in 2 phases, 25% dose in 1 phase). The phase of enhancement most relevant to the diagnostic task was selected for evaluation. Four radiologists reviewed routine-dose and lower-dose PIR images, circumscribing liver lesions and rating confidence for malignancy (0 to 100) and image quality. JAFROC Figures of Merit (FOM) were calculated. RESULTS 31 patients had 60 liver lesions (28 primary hepatic malignancies, 6 hepatic metastases, 26 benign lesions). Pooled JAFROC FOM for malignancy for routine-dose CT was 0.615 (95% CI 0.464, 0.767) compared to 0.662 for PIR (95% CI 0.527, 0.797). The estimated FOM difference between the routine-dose and lower-dose PIR images was + 0.047 (95% CI - 0.023, + 0.116). Pooled sensitivity/specificity for routine-dose images was 70%/68% compared to 73%/66% for lower-dose PIR. Lower-dose PIR had lower diagnostic image quality (mean 3.8 vs. 4.2, p = 0.0009) and sharpness (mean 2.3 vs. 2.0, p = 0.0071). CONCLUSIONS PIR is a promising method to reduce radiation dose for multiphase abdominal CT, preserving observer performance despite small reductions in image quality. Further work is warranted.
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Abstract
CLINICAL/METHODICAL ISSUE Computed tomography (CT) acquisition should be performed following the ALARA principle: keeping patient radiation exposure as low as reasonably achievable. STANDARD RADIOLOGICAL METHODS Reconstruction with filtered backprojection is still the standard in CT. METHODICAL INNOVATIONS Recently, iterative reconstruction techniques have become available, using a different approach for image reconstruction. A similar approach is used for iterative metal artifact reduction. PERFORMANCE Compared to filtered backprojection, iterative reconstruction yields improvements in image quality and reduces image noise. ACHIEVEMENTS Using iterative reconstruction allows the reduction of patient radiation exposure by up to 80%, depending on the used algorithm and the clinical task at hand. With the help of iterative metal artifact reduction, images of diagnostic quality can be acquired despite metal implants. PRACTICAL RECOMMENDATIONS Iterative reconstruction should be used to reduce patient radiation exposure in accordance with the clinical requirements. The use of iterative metal artifact reduction is recommended.
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Lin S, Lin M, Lau K. Efficacy of model-based iterative reconstruction in cystic fibrosis assessment using CT. Clin Radiol 2019; 74:569.e19-569.e27. [DOI: 10.1016/j.crad.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/11/2019] [Indexed: 02/03/2023]
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Lin S, Lin M, Lau KK. Image quality comparison between model-based iterative reconstruction and adaptive statistical iterative reconstruction chest computed tomography in cystic fibrosis patients. J Med Imaging Radiat Oncol 2019; 63:602-609. [PMID: 31090256 DOI: 10.1111/1754-9485.12895] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 04/10/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Cystic fibrosis (CF) predominantly affects young adults. Accurate radiological assessment of pulmonary disease is vital for predicting exacerbations, one of the leading causes of morbidity and mortality. We evaluated the image quality of model-based iterative reconstruction (MBIR) ultra-low-dose CT chest (ULD-CT) in CF evaluation. METHODS We compared ULD-CT with standard adaptive statistical iterative reconstruction (ASIR) low-dose CT (LD-CT). Subjective assessment of contrast and noise were performed for each study. Background noise, signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated and compared between the CT studies. Conspicuity of major structures was assessed. These aspects of image quality were compared to determine whether ULD-CT was superior to LD-CT in assessment of CF. RESULTS The ULD-CT achieved median effective dose of 0.073 mSv, comparable to one standard chest radiograph and significantly lower than the median LD-CT dose of 1.22 mSv. ULD-CT had lower subjective contrast and higher subjective noise when compared to LD-CT. Objectively measured background noise was lower in ULD-CT (16.33 HU vs 38.53 HU, P < 0.0001) compared to LD-CT. ULD-CT had higher median CNR (52.65 vs 22.09, P < 0.0001) and SNR in lung (9.08 vs 7.29, P = 0.002) compared to LD-CT. ULD-CT was equal to LD-CT in identification of trachea, bronchi, pleural and pericardium. Interobserver reliability showed agreement of 80-92%. CONCLUSIONS The image quality of ULD-CT is similar to LD-CT, at 1/16th the dose. MBIR constructed ULD-CT is an effective imaging modality for CF surveillance, with potential applications in other disease settings.
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Affiliation(s)
- Sandra Lin
- Austin Health, Melbourne, Victoria, Australia
| | - Monica Lin
- Department of Diagnostic Imaging, Monash Health, Melbourne, Victoria, Australia
| | - Kenneth K Lau
- Department of Diagnostic Imaging, Monash Health, Melbourne, Victoria, Australia.,Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
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Hamamura T, Hayashida Y, Takeshita Y, Sugimoto K, Ueda I, Futatsuya K, Kakeda S, Aoki T, Korogi Y. The usefulness of full-iterative reconstruction algorithm for the visualization of cystic artery on CT angiography. Jpn J Radiol 2019; 37:526-533. [PMID: 31041661 DOI: 10.1007/s11604-019-00839-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/08/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE To evaluate the potential of full-iterative reconstruction (IR) for improving image quality of the cystic artery on CT angiography and to assess observer performance. METHODS Thirty patients who underwent both liver dynamic CT and conventional angiography were included in this retrospective study. All CT data were reconstructed through filtered back projection (FBP), adaptive iterative dose reduction 3D (AIDR3D), and forward-projected, model-based, iterative reconstruction solution (FIRST), respectively. In objective study, we analyzed mean ΔCT numbers (the difference between the HU peak of the vessel and the background) and full-width at tenth-maximum (FWTM) of three parts of the cystic artery by profile curve method comparing the three reconstructions. Subjectively, visualization was evaluated using a four-point scale performed by two blinded observers. ANOVA was used for statistical analysis. RESULTS In all parts of the cystic artery, the mean ΔCT number of FIRST was shown to be significantly better than that of FBP and AIDR3D (p < 0.05). FWTM in FIRST was the smallest in all of the vessels. The mean visualization score was significantly better with FIRST than with other CT reconstructions (p < 0.05). CONCLUSIONS The FIRST algorithm led to improved CTA visualization of the cystic artery.
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Affiliation(s)
- Toshihiko Hamamura
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
| | - Yoshiko Hayashida
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Yohei Takeshita
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Koichiro Sugimoto
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Issei Ueda
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Koichiro Futatsuya
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Shingo Kakeda
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Takatoshi Aoki
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
| | - Yukunori Korogi
- Department of Radiology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan
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Afzelius P, Nielsen OL, Schønheyder HC, Alstrup A, Hansen SB. An untapped potential for imaging of peripheral osteomyelitis in paediatrics using [ 18F]FDG PET/CT -the inference from a juvenile porcine model. EJNMMI Res 2019; 9:29. [PMID: 30903403 PMCID: PMC6430261 DOI: 10.1186/s13550-019-0498-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 03/11/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To examine parameters affecting the detection of osteomyelitis (OM) by [18F]FDG PET/CT and to reduce tracer activity in a pig model. BACKGROUND [18F]FDG PET/CT is recommended for the diagnosis of OM in the axial skeleton of adults. In children, OM has a tendency to become chronic or recurrent, especially in low-income countries. Early diagnosis and initiation of therapy are therefore essential. We have previously demonstrated that [18F]FDG PET/CT is promising in juvenile Staphylococcus aureus (S. aureus) OM of peripheral bones in a pig model, not failing even small lesions. When using imaging in children, radiation exposure should be balanced against fast diagnostics in the individual case. METHODS Twenty juvenile pigs were inoculated with S. aureus. One week after inoculation, the pigs were [18F]FDG PET/CT scanned. PET list-mode acquired data of a subgroup were retrospectively processed in order to simulate and examine the image quality obtainable with an injected activity of 132 MBq, 44 MBq, 13.2 MBq, and 4.4 MBq, respectively. RESULTS All lesions were detected by [18F]FDG PET and CT. Some lesions were very small (0.01 cm3), and others were larger (4.18 cm3). SUVmax was higher when sequesters (p = 0.023) and fistulas were formed (p < 0.0001). The simulated data demonstrated that it was possible to reduce the activity to 4.4 MBq without compromising image quality in pigs. CONCLUSIONS [18F]FDG PET/CT localized even small OM lesions in peripheral bones. It was possible to reduce the injected activity considerably without compromising image quality, impacting the applicability of PET/CT in peripheral OM in children.
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Affiliation(s)
- P. Afzelius
- Department of Diagnostic Imaging, Section of Clinical Physiology and Nuclear Medicine, North Zealand Hospital, Dyrehavevej 29, 3400 Hillerod, Denmark
- Department of Nuclear Medicine, Aalborg University Hospital, Aalborg, Denmark
| | - O. L. Nielsen
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - H. C. Schønheyder
- Department of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - A.K.O. Alstrup
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - S. B. Hansen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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Task-Based Model Observer Assessment of A Partial Model-Based Iterative Reconstruction Algorithm in Thoracic Oncologic Multidetector CT. Sci Rep 2018; 8:17734. [PMID: 30531988 PMCID: PMC6286352 DOI: 10.1038/s41598-018-36045-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/14/2018] [Indexed: 12/14/2022] Open
Abstract
To investigate the impact of a partial model-based iterative reconstruction (ASiR-V) on image quality in thoracic oncologic multidetector computed tomography (MDCT), using human and mathematical model observers. Twenty cancer patients examined with regular-dose thoracic-abdominal-pelvic MDCT were retrospectively included. Thoracic images reconstructed using a sharp kernel and filtered back-projection (reference) or ASiR-V (0-100%, 20% increments; follow-up) were analysed by three thoracic radiologists. Advanced quantitative physical metrics, including detectability indexes of simulated 4-mm-diameter solid non-calcified nodules and ground-glass opacities, were computed at regular and reduced doses using a custom-designed phantom. All three radiologists preferred higher ASiR-V levels (best = 80%). Increasing ASiR-V substantially decreased noise magnitude, with slight changes in noise texture. For high-contrast objects, changing the ASiR-V level had no major effect on spatial resolution; whereas for lower-contrast objects, increasing ASiR-V substantially decreased spatial resolution, more markedly at reduced dose. For both high- and lower-contrast pulmonary lesions, detectability remained excellent, regardless of ASiR-V and dose levels, and increased significantly with increasing ASiR-V levels (all p < 0.001). While high ASiR-V levels (80%) are recommended to detect solid non-calcified nodules and ground-glass opacities in regular-dose thoracic oncologic MDCT, care must be taken because, for lower-contrast pulmonary lesions, high ASiR-V levels slightly change noise texture and substantially decrease spatial resolution, more markedly at reduced dose.
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den Harder AM, de Boer E, Lagerweij SJ, Boomsma MF, Schilham AMR, Willemink MJ, Milles J, Leiner T, Budde RPJ, de Jong PA. Emphysema quantification using chest CT: influence of radiation dose reduction and reconstruction technique. Eur Radiol Exp 2018; 2:30. [PMID: 30402740 PMCID: PMC6220000 DOI: 10.1186/s41747-018-0064-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/06/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Computed tomography (CT) emphysema quantification is affected by both radiation dose (i.e. image noise) and reconstruction technique. At reduced dose, filtered back projection (FBP) results in an overestimation of the amount of emphysema due to higher noise levels, while the use of iterative reconstruction (IR) can result in an underestimation due to reduced noise. The objective of this study was to determine the influence of dose reduction and hybrid IR (HIR) or model-based IR (MIR) on CT emphysema quantification. METHODS Twenty-two patients underwent inspiratory chest CT scan at routine radiation dose and at 45%, 60% and 75% reduced radiation dose. Acquisitions were reconstructed with FBP, HIR and MIR. Emphysema was quantified using the 15th percentile of the attenuation curve and the percentage of voxels below -950 HU. To determine whether the use of a different percentile or HU threshold is more accurate at reduced dose levels and with IR, additional measurements were performed using different percentiles and HU thresholds to determine the optimal combination. RESULTS Dose reduction resulted in a significant overestimation of emphysema, while HIR and MIR resulted in an underestimation. Lower HU thresholds with FBP at reduced dose and higher HU thresholds with HIR and MIR resulted in emphysema percentages comparable to the reference. The 15th percentile quantification method showed similar results as the HU threshold method. CONCLUSIONS This within-patients study showed that CT emphysema quantification is significantly affected by dose reduction and IR. This can potentially be solved by adapting commonly used thresholds.
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Affiliation(s)
| | - Erwin de Boer
- Department of Radiology, Isala hospital, Zwolle, The Netherlands
| | - Suzanne J Lagerweij
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Arnold M R Schilham
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Martin J Willemink
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
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Willemink MJ, Noël PB. The evolution of image reconstruction for CT-from filtered back projection to artificial intelligence. Eur Radiol 2018; 29:2185-2195. [PMID: 30377791 PMCID: PMC6443602 DOI: 10.1007/s00330-018-5810-7] [Citation(s) in RCA: 261] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/12/2018] [Accepted: 09/27/2018] [Indexed: 12/22/2022]
Abstract
Abstract The first CT scanners in the early 1970s already used iterative reconstruction algorithms; however, lack of computational power prevented their clinical use. In fact, it took until 2009 for the first iterative reconstruction algorithms to come commercially available and replace conventional filtered back projection. Since then, this technique has caused a true hype in the field of radiology. Within a few years, all major CT vendors introduced iterative reconstruction algorithms for clinical routine, which evolved rapidly into increasingly advanced reconstruction algorithms. The complexity of algorithms ranges from hybrid-, model-based to fully iterative algorithms. As a result, the number of scientific publications on this topic has skyrocketed over the last decade. But what exactly has this technology brought us so far? And what can we expect from future hardware as well as software developments, such as photon-counting CT and artificial intelligence? This paper will try answer those questions by taking a concise look at the overall evolution of CT image reconstruction and its clinical implementations. Subsequently, we will give a prospect towards future developments in this domain. Key Points • Advanced CT reconstruction methods are indispensable in the current clinical setting. • IR is essential for photon-counting CT, phase-contrast CT, and dark-field CT. • Artificial intelligence will potentially further increase the performance of reconstruction methods.
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Affiliation(s)
- Martin J Willemink
- Department of Radiology, Stanford University School of Medicine, 300 Pasteur Drive, Room M-039, Stanford, CA, 94305-5105, USA. .,Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
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Gariani J, Martin SP, Botsikas D, Becker CD, Montet X. Evaluating the effect of increased pitch, iterative reconstruction and dual source CT on dose reduction and image quality. Br J Radiol 2018; 91:20170443. [PMID: 29762055 PMCID: PMC6209470 DOI: 10.1259/bjr.20170443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Objective: To compare radiation dose and image quality of thoracoabdominal scans obtained with a high-pitch protocol (pitch 3.2) and iterative reconstruction (Sinogram Affirmed Iterative Reconstruction) in comparison to standard pitch reconstructed with filtered back projection (FBP) using dual source CT. Methods: 114 CT scans (Somatom Definition Flash, Siemens Healthineers, Erlangen, Germany), 39 thoracic scans, 54 thoracoabdominal scans and 21 abdominal scans were performed. Analysis of three protocols was undertaken; pitch of 1 reconstructed with FBP, pitch of 3.2 reconstructed with SAFIRE, pitch of 3.2 with stellar detectors reconstructed with SAFIRE. Objective and subjective image analysis were performed. Dose differences of the protocols used were compared. Results: Dose was reduced when comparing scans with a pitch of 1 reconstructed with FBP to high-pitch scans with a pitch of 3.2 reconstructed with SAFIRE with a reduction of volume CT dose index of 75% for thoracic scans, 64% for thoracoabdominal scans and 67% for abdominal scans. There was a further reduction after the implementation of stellar detectors reflected in a reduction of 36% of the dose–length product for thoracic scans. This was not at the detriment of image quality, contrast-to-noise ratio, signal-to-noise ratio and the qualitative image analysis revealed a superior image quality in the high-pitch protocols. Conclusion: The combination of a high pitch protocol with iterative reconstruction allows significant dose reduction in routine chest and abdominal scans whilst maintaining or improving diagnostic image quality, with a further reduction in thoracic scans with stellar detectors. Advances in knowledge: High pitch imaging with iterative reconstruction is a tool that can be used to reduce dose without sacrificing image quality.
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Affiliation(s)
- Joanna Gariani
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Steve P Martin
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Diomidis Botsikas
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Christoph D Becker
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
| | - Xavier Montet
- 1 Division of Radiology, Department of Imaging and Medical Information Sciences, Geneva University Hospitals , Geneva , Switzerland
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Tan SK, Yeong CH, Raja Aman RRA, Ng KH, Abdul Aziz YF, Chee KH, Sun Z. Low tube voltage prospectively ECG-triggered coronary CT angiography: a systematic review of image quality and radiation dose. Br J Radiol 2018; 91:20170874. [PMID: 29493261 DOI: 10.1259/bjr.20170874] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE This study aimed (1) to perform a systematic review on scanning parameters and contrast medium (CM) reduction methods used in prospectively electrocardiography (ECG-triggered low tube voltage coronary CT angiography (CCTA), (2) to compare the achievable dose reduction and image quality and (3) to propose appropriate scanning techniques and CM administration methods. METHODS A systematic search was performed in PubMed, the Cochrane library, CINAHL, Web of Science, ScienceDirect and Scopus, where 20 studies were selected for analysis of scanning parameters and CM reduction methods. RESULTS The mean effective dose (HE) ranged from 0.31 to 2.75 mSv at 80 kVp, 0.69 to 6.29 mSv at 100 kVp and 1.53 to 10.7 mSv at 120 kVp. Radiation dose reductions of 38 to 83% at 80 kVp and 3 to 80% at 100 kVp could be achieved with preserved image quality. Similar vessel contrast enhancement to 120 kVp could be obtained by applying iodine delivery rate (IDR) of 1.35 to 1.45 g s-1 with total iodine dose (TID) of between 10.9 and 16.2 g at 80 kVp and IDR of 1.08 to 1.70 g s-1 with TID of between 18.9 and 20.9 g at 100 kVp. CONCLUSION This systematic review found that radiation doses could be reduced to a rate of 38 to 83% at 80 kVp, and 3 to 80% at 100 kVp without compromising the image quality. Advances in knowledge: The suggested appropriate scanning parameters and CM reduction methods can be used to help users in achieving diagnostic image quality with reduced radiation dose.
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Affiliation(s)
- Sock Keow Tan
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Chai Hong Yeong
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | | | - Kwan Hoong Ng
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Yang Faridah Abdul Aziz
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Kok Han Chee
- 1 Department of Biomedical Imaging, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia.,2 Department of Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Zhonghua Sun
- 3 Department of Medical Radiation Sciences, Curtin University , Perth, WA , Australia
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Si-Mohamed S, Greffier J, Bobbia X, Larbi A, Delicque J, Khasanova E, Beregi JP, Macri F. Diagnostic performance of a low dose triple rule-out CT angiography using SAFIRE in emergency department. Diagn Interv Imaging 2017; 98:881-891. [DOI: 10.1016/j.diii.2017.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/07/2017] [Accepted: 09/07/2017] [Indexed: 12/13/2022]
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Sardanelli F. Trends in radiology and experimental research. Eur Radiol Exp 2017; 1:1. [PMID: 29708170 PMCID: PMC5909338 DOI: 10.1186/s41747-017-0006-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/15/2017] [Indexed: 12/19/2022] Open
Abstract
European Radiology Experimental, the new journal launched by the European Society of Radiology, is placed in the context of three general and seven radiology-specific trends. After describing the impact of population aging, personalized/precision medicine, and information technology development, the article considers the following trends: the tension between subspecialties and the unity of the discipline; attention to patient safety; the challenge of reproducibility for quantitative imaging; standardized and structured reporting; search for higher levels of evidence in radiology (from diagnostic performance to patient outcome); the increasing relevance of interventional radiology; and continuous technological evolution. The new journal will publish not only studies on phantoms, cells, or animal models but also those describing development steps of imaging biomarkers or those exploring secondary end-points of large clinical trials. Moreover, consideration will be given to studies regarding: computer modelling and computer aided detection and diagnosis; contrast materials, tracers, and theranostics; advanced image analysis; optical, molecular, hybrid and fusion imaging; radiomics and radiogenomics; three-dimensional printing, information technology, image reconstruction and post-processing, big data analysis, teleradiology, clinical decision support systems; radiobiology; radioprotection; and physics in radiology. The journal aims to establish a forum for basic science, computer and information technology, radiology, and other medical subspecialties.
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Affiliation(s)
- Francesco Sardanelli
- Department of Biomedical Sciences for Health, Università degli Studi di Milano and Unit of Radiology, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan Italy
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Scholz O, Denecke T, Böttcher J, Schwarz C, Mentzel HJ, Streitparth F, Maurer MH, Pfeil A, Huppertz A, Mehl A, Staab D, Hamm B, Renz DM. MRI of cystic fibrosis lung manifestations: sequence evaluation and clinical outcome analysis. Clin Radiol 2017; 72:754-763. [PMID: 28545684 DOI: 10.1016/j.crad.2017.03.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/19/2017] [Accepted: 03/20/2017] [Indexed: 11/17/2022]
Abstract
AIM To evaluate different magnetic resonance imaging (MRI) sequences for diagnosis of pulmonary manifestations of cystic fibrosis (CF) in comparison to chest computed tomography (CT), including an extended outcome analysis. MATERIALS AND METHODS Twenty-eight patients with CF (15 male, 13 female, mean age 30.5±9.4 years) underwent CT and MRI of the lung. MRI (1.5 T) included different T2- and T1-weighted sequences: breath-hold HASTE (half Fourier acquisition single shot turbo spin echo) and VIBE (volumetric interpolated breath-hold examination, before and after contrast medium administration) sequences and respiratory-triggered PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) sequences with and without fat signal suppression, and perfusion imaging. CT and MRI images were evaluated by the modified Helbich and the Eichinger scoring systems. The clinical follow-up analysis assessed pulmonary exacerbations within 24 months. RESULTS The highest concordance to CT was achieved for the PROPELLER sequences without fat signal suppression (concordance correlation coefficient CCC of the overall modified Helbich score 0.93 and of the overall Eichinger score 0.93). The other sequences had the following concordance: PROPELLER with fat signal suppression (CCCs 0.91 and 0.92), HASTE (CCCs 0.87 and 0.89), VIBE (CCCs 0.84 and 0.85) sequences. In the outcome analysis, the combined MRI analysis of all five sequences and a specific MRI protocol (PROPELLER without fast signal suppression, VIBE sequences, perfusion imaging) reached similar correlations to the number of pulmonary exacerbations as the CT examinations. CONCLUSION An optimum lung MRI protocol in patients with CF consists of PROPELLER sequences without fat signal suppression, VIBE sequences, and lung perfusion analysis to enable high diagnostic efficacy and outcome prediction.
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Affiliation(s)
- O Scholz
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - T Denecke
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - J Böttcher
- Institute of Diagnostic and Interventional Radiology, SRH Clinic Gera, Str. des Friedens 122, 07548 Gera, Germany
| | - C Schwarz
- Division of Pulmonology and Immunology, Department of Pediatrics, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - H-J Mentzel
- Institute of Diagnostic and Interventional Radiology, Department of Pediatric Radiology, Friedrich-Schiller-University, Jena University Hospital, Am Klinikum 1, 07740 Jena, Germany
| | - F Streitparth
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - M H Maurer
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - A Pfeil
- Department of Internal Medicine III, Friedrich-Schiller-University, Jena University Hospital, Am Klinikum 1, 07740 Jena, Germany
| | - A Huppertz
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - A Mehl
- Division of Pulmonology and Immunology, Department of Pediatrics, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - D Staab
- Division of Pulmonology and Immunology, Department of Pediatrics, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - B Hamm
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany
| | - D M Renz
- Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany; Institute of Diagnostic and Interventional Radiology, Department of Pediatric Radiology, Friedrich-Schiller-University, Jena University Hospital, Am Klinikum 1, 07740 Jena, Germany.
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Aschoff AJ, Catalano C, Kirchin MA, Krix M, Albrecht T. Low radiation dose in computed tomography: the role of iodine. Br J Radiol 2017; 90:20170079. [PMID: 28471242 PMCID: PMC5603952 DOI: 10.1259/bjr.20170079] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Recent approaches to reducing radiation exposure during CT examinations typically utilize automated dose modulation strategies on the basis of lower tube voltage combined with iterative reconstruction and other dose-saving techniques. Less clearly appreciated is the potentially substantial role that iodinated contrast media (CM) can play in low-radiation-dose CT examinations. Herein we discuss the role of iodinated CM in low-radiation-dose examinations and describe approaches for the optimization of CM administration protocols to further reduce radiation dose and/or CM dose while maintaining image quality for accurate diagnosis. Similar to the higher iodine attenuation obtained at low-tube-voltage settings, high-iodine-signal protocols may permit radiation dose reduction by permitting a lowering of mAs while maintaining the signal-to-noise ratio. This is particularly feasible in first pass examinations where high iodine signal can be achieved by injecting iodine more rapidly. The combination of low kV and IR can also be used to reduce the iodine dose. Here, in optimum contrast injection protocols, the volume of CM administered rather than the iodine concentration should be reduced, since with high-iodine-concentration CM further reductions of iodine dose are achievable for modern first pass examinations. Moreover, higher concentrations of CM more readily allow reductions of both flow rate and volume, thereby improving the tolerability of contrast administration.
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Affiliation(s)
- Andrik J Aschoff
- 1 Department for Diagnostic and Interventional Radiology and Neuroradiology, Klinikum Kempten, Kempten, Germany
| | - Carlo Catalano
- 2 Department of Radiological Sciences, University of Rome "La Sapienza", Rome, Italy
| | - Miles A Kirchin
- 3 Bracco Imaging SpA, Global Medical & Regulatory Affairs, Milan, Italy
| | - Martin Krix
- 4 Bracco Imaging Germany, Global Medical & Regulatory Affairs, Konstanz, Germany
| | - Thomas Albrecht
- 5 Institut für Radiologie und Interventionelle Therapie, Vivantes-Klinikum Neukölln, Berlin, Germany
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Radiation dose-reduction strategies in thoracic CT. Clin Radiol 2017; 72:407-420. [DOI: 10.1016/j.crad.2016.11.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/31/2016] [Accepted: 11/14/2016] [Indexed: 01/08/2023]
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Rampinelli C, De Marco P, Origgi D, Maisonneuve P, Casiraghi M, Veronesi G, Spaggiari L, Bellomi M. Exposure to low dose computed tomography for lung cancer screening and risk of cancer: secondary analysis of trial data and risk-benefit analysis. BMJ 2017; 356:j347. [PMID: 28179230 PMCID: PMC5421449 DOI: 10.1136/bmj.j347] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Objective To estimate the cumulative radiation exposure and lifetime attributable risk of cancer incidence associated with lung cancer screening using annual low dose computed tomography (CT).Design Secondary analysis of data from a lung cancer screening trial and risk-benefit analysis.Setting 10 year, non-randomised, single centre, low dose CT, lung cancer screening trial (COSMOS study) which took place in Milan, Italy in 2004-15 (enrolment in 2004-05). Secondary analysis took place in 2015-16.Participants High risk asymptomatic smokers aged 50 and older, who were current or former smokers (≥20 pack years), and had no history of cancer in the previous five years.Main outcome measures Cumulative radiation exposure from low dose CT and positron emission tomography (PET) CT scans, calculated by dosimetry software; and lifetime attributable risk of cancer incidence, calculated from the Biological Effects of Ionizing Radiation VII (BEIR VII) report.Results Over 10 years, 5203 participants (3439 men, 1764 women) underwent 42 228 low dose CT and 635 PET CT scans. The median cumulative effective dose at the 10th year of screening was 9.3 mSv for men and 13.0 mSv for women. According to participants' age and sex, the lifetime attributable risk of lung cancer and major cancers after 10 years of CT screening ranged from 5.5 to 1.4 per 10 000 people screened, and from 8.1 to 2.6 per 10 000 people screened, respectively. In women aged 50-54, the lifetime attributable risk of lung cancer and major cancers was about fourfold and threefold higher than for men aged 65 and older, respectively. The numbers of lung cancer and major cancer cases induced by 10 years of screening in our cohort were 1.5 and 2.4, respectively, which corresponded to an additional risk of induced major cancers of 0.05% (2.4/5203). 259 lung cancers were diagnosed in 10 years of screening; one radiation induced major cancer would be expected for every 108 (259/2.4) lung cancers detected through screening.Conclusion Radiation exposure and cancer risk from low dose CT screening for lung cancer, even if non-negligible, can be considered acceptable in light of the substantial mortality reduction associated with screening.
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Affiliation(s)
- Cristiano Rampinelli
- Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, Milan, Italy
| | - Paolo De Marco
- Medical Physics School, University of Milan, Milan, Italy
| | - Daniela Origgi
- Division of Medical Physics, European Institute of Oncology, Milan, Italy
| | - Patrick Maisonneuve
- Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan, Italy
| | - Monica Casiraghi
- Division of Thoracic Surgery, European Institute of Oncology, Milan, Italy
| | - Giulia Veronesi
- Division of Thoracic Surgery, European Institute of Oncology, Milan, Italy
- Division of Thoracic Surgery, Humanitas Research Hospital, Rozzano, Italy
| | - Lorenzo Spaggiari
- Division of Thoracic Surgery, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hematology-Oncology, University of Milan, Milan, Italy
| | - Massimo Bellomi
- Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, Milan, Italy
- Department of Oncology and Hematology-Oncology, University of Milan, Milan, Italy
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Nomura Y, Higaki T, Fujita M, Miki S, Awaya Y, Nakanishi T, Yoshikawa T, Hayashi N, Awai K. Effects of Iterative Reconstruction Algorithms on Computer-assisted Detection (CAD) Software for Lung Nodules in Ultra-low-dose CT for Lung Cancer Screening. Acad Radiol 2017; 24:124-130. [PMID: 27986507 DOI: 10.1016/j.acra.2016.09.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 09/21/2016] [Accepted: 09/25/2016] [Indexed: 02/06/2023]
Abstract
RATIONALE AND OBJECTIVES This study aimed to evaluate the effects of iterative reconstruction (IR) algorithms on computer-assisted detection (CAD) software for lung nodules in ultra-low-dose computed tomography (ULD-CT) for lung cancer screening. MATERIALS AND METHODS We selected 85 subjects who underwent both a low-dose CT (LD-CT) scan and an additional ULD-CT scan in our lung cancer screening program for high-risk populations. The LD-CT scans were reconstructed with filtered back projection (FBP; LD-FBP). The ULD-CT scans were reconstructed with FBP (ULD-FBP), adaptive iterative dose reduction 3D (AIDR 3D; ULD-AIDR 3D), and forward projected model-based IR solution (FIRST; ULD-FIRST). CAD software for lung nodules was applied to each image dataset, and the performance of the CAD software was compared among the different IR algorithms. RESULTS The mean volume CT dose indexes were 3.02 mGy (LD-CT) and 0.30 mGy (ULD-CT). For overall nodules, the sensitivities of CAD software at 3.0 false positives per case were 78.7% (LD-FBP), 9.3% (ULD-FBP), 69.4% (ULD-AIDR 3D), and 77.8% (ULD-FIRST). Statistical analysis showed that the sensitivities of ULD-AIDR 3D and ULD-FIRST were significantly higher than that of ULD-FBP (P < .001). CONCLUSIONS The performance of CAD software in ULD-CT was improved by using IR algorithms. In particular, the performance of CAD in ULD-FIRST was almost equivalent to that in LD-FBP.
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Kubo T, Ohno Y, Seo JB, Yamashiro T, Kalender WA, Lee CH, Lynch DA, Kauczor HU, Hatabu H. Securing safe and informative thoracic CT examinations—Progress of radiation dose reduction techniques. Eur J Radiol 2017; 86:313-319. [DOI: 10.1016/j.ejrad.2016.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/08/2016] [Accepted: 10/12/2016] [Indexed: 12/16/2022]
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Aortic Valve and Thoracic Aortic Calcification Measurements: How Low Can We Go in Radiation Dose? J Comput Assist Tomogr 2016; 41:148-155. [PMID: 27560017 DOI: 10.1097/rct.0000000000000477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE This study aimed to determine the lowest radiation dose and iterative reconstruction level(s) at which computed tomography (CT)-based quantification of aortic valve calcification (AVC) and thoracic aortic calcification (TAC) is still feasible. METHODS Twenty-eight patients underwent a cardiac CT and 20 patients a chest CT at 4 different dose levels (routine dose and approximately 40%, 60%, and 80% reduced dose). Data were reconstructed with filtered back projection, 3 iDose levels, and 3 iterative model-based reconstruction levels. Two observers scored subjective image quality. The AVC and TAC were quantified using mass and compared to the reference scan (routine dose reconstructed with filtered back projection). RESULTS In cardiac CT at 0.35 mSv (60% reduced), all scans reconstructed with iDose (all levels) were diagnostic, calcification detection errors occurred in only 1 patient, and there were no significant differences in mass scores compared to the reference scan. Similar results were found for chest CT at 0.48 mSv (75% reduced) with iDose levels 4 and 6 and iterative model reconstruction levels 1 and 2. CONCLUSIONS Iterative reconstruction enables AVC and TAC quantification on CT at submillisievert dose.
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Effect of computed tomography before cardiac surgery on surgical strategy, mortality and stroke. Eur J Radiol 2016; 85:744-50. [DOI: 10.1016/j.ejrad.2016.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 01/04/2016] [Accepted: 01/11/2016] [Indexed: 12/27/2022]
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Leitão Filho FS, Hang Chen H, Ngan DA, Tam A, Kirby M, Sin DD. Current methods to diagnose small airway disease in patients with COPD. Expert Rev Respir Med 2016; 10:417-429. [PMID: 26890226 DOI: 10.1586/17476348.2016.1155455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The small airways are characterized by an internal diameter < 2 mm and absence of cartilage. Approximately 10-25% of total airway resistance in healthy lungs is due to the small airways, with their contribution to total airway resistance increasing substantially in chronic obstructive pulmonary disease (COPD). As the small airways are located in the lung periphery, they are not easily evaluable, which can potentially interfere with the diagnosis (especially at early stages), monitoring, detection of responses to clinical interventions, and prognostic evaluation in COPD. Here, we will discuss the currently available methods in clinical practice to evaluate small airway disease in COPD, focusing on the concept, advantages, and disadvantages of each method.
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Affiliation(s)
- Fernando Sergio Leitão Filho
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
| | - Hao Hang Chen
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
| | - David A Ngan
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
| | - Anthony Tam
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
| | - Miranda Kirby
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
| | - Don D Sin
- a Centre for Heart Lung Innovation, St. Paul´s Hospital, & Department of Medicine , University of British Columbia , Vancouver , British Columbia , Canada
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den Harder AM, de Heer LM, Maurovich-Horvat P, Merkely B, de Jong PA, Das M, de Wit GA, Leiner T, Budde RPJ. Ultra low-dose chest ct with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery (CRICKET study): Rationale and design of a multicenter randomized trial. J Cardiovasc Comput Tomogr 2016; 10:242-5. [PMID: 26857421 DOI: 10.1016/j.jcct.2016.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/18/2016] [Accepted: 01/26/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Stroke after cardiac surgery is a severe complication with a persistently high incidence of 1.4 - 9.7%. Postoperative strokes are mainly embolic and can be provoked by manipulation and clamping of the aorta during cardiac surgery, resulting in the mobilization of atherothrombotic material and calcifications from the aortic wall. Computed tomography (CT) can offer preoperative visualization of aortic calcifications with low radiation exposure. We hypothesize that preoperative knowledge regarding the location and extent of aortic calcifications can be used to optimize surgical strategy and decrease postoperative stroke rate. METHODS/DESIGN The CRICKET study (ultra low-dose chest CT with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery) is a prospective multicenter randomized clinical trial to evaluate whether non-contrast chest CT before cardiac surgery can decrease postoperative stroke rate by optimizing surgical strategy. Patients scheduled to undergo cardiac surgery aged 18 years and older are eligible for inclusion. Exclusion criteria are pregnancy, a chest/cardiac CT in the past three months, emergency surgery, concomitant or prior participation in a study with ionizing radiation and unwillingness to be informed about incidental findings. Subjects (n = 1.724) are randomized between routine care, including a chest x-ray, or routine care with an additional low dose chest CT. The primary objective is to investigate whether the postoperative in-hospital stroke rate is reduced in the CT arm compared to the routine care arm of the randomized trial. The secondary outcome measures are altered surgical approach based on CT findings and cost-effectiveness.
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Affiliation(s)
- Annemarie M den Harder
- Department of Radiology, University Medical Center, P.O. Box 85000, 3508GA Utrecht, The Netherlands.
| | - Linda M de Heer
- Department of Cardiothoracic Surgery, University Medical Center, P.O. Box 85000, 3508GA Utrecht, The Netherlands
| | - Pal Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68 Varosmajor ut, Budapest 1122, Hungary
| | - Bela Merkely
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68 Varosmajor ut, Budapest 1122, Hungary
| | - Pim A de Jong
- Department of Radiology, University Medical Center, P.O. Box 85000, 3508GA Utrecht, The Netherlands
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P.O. Box 5800, 6202AZ Maastricht, The Netherlands
| | - G Ardine de Wit
- Department of Epidemiology, Julius Center for Health Sciences and Primary Care, P.O. Box 85000, 3508GA Utrecht, The Netherlands; National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center, P.O. Box 85000, 3508GA Utrecht, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology, Erasmus Medical Center, P.O. Box 2040, 3000CA Rotterdam, The Netherlands
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Pulmonary Nodule Volumetry at Different Low Computed Tomography Radiation Dose Levels With Hybrid and Model-Based Iterative Reconstruction. J Comput Assist Tomogr 2016; 40:578-83. [DOI: 10.1097/rct.0000000000000408] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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