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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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Summary for Clinicians: Clinical Practice Guidelines for Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease. Ann Am Thorac Soc 2022; 19:873-879. [PMID: 35239469 DOI: 10.1513/annalsats.202201-007cme] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Cristea AI, Ren CL, Amin R, Eldredge LC, Levin JC, Majmudar PP, May AE, Rose RS, Tracy MC, Watters KF, Allen J, Austin ED, Cataletto ME, Collaco JM, Fleck RJ, Gelfand A, Hayes D, Jones MH, Kun SS, Mandell EW, McGrath-Morrow SA, Panitch HB, Popatia R, Rhein LM, Teper A, Woods JC, Iyer N, Baker CD. Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med 2021; 204:e115-e133. [PMID: 34908518 PMCID: PMC8865713 DOI: 10.1164/rccm.202110-2269st] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.
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Higano NS, Ruoss JL, Woods JC. Modern pulmonary imaging of bronchopulmonary dysplasia. J Perinatol 2021; 41:707-717. [PMID: 33547408 PMCID: PMC8561744 DOI: 10.1038/s41372-021-00929-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/05/2020] [Accepted: 01/15/2021] [Indexed: 01/30/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is a complex and serious cardiopulmonary morbidity in infants who are born preterm. Despite advances in clinical care, BPD remains a significant source of morbidity and mortality, due in large part to the increased survival of extremely preterm infants. There are few strong early prognostic indicators of BPD or its later outcomes, and evidence for the usage and timing of various interventions is minimal. As a result, clinical management is often imprecise. In this review, we highlight cutting-edge methods and findings from recent pulmonary imaging research that have high translational value. Further, we discuss the potential role that various radiological modalities may play in early risk stratification for development of BPD and in guiding treatment strategies of BPD when employed in varying severities and time-points throughout the neonatal disease course.
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Affiliation(s)
- Nara S Higano
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Cincinnati Bronchopulmonary Dysplasia Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - J Lauren Ruoss
- Division of Neonatology, Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Jason C Woods
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Cincinnati Bronchopulmonary Dysplasia Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA.
- Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH, USA.
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Facchini G, Ceccarelli L, Tomà P, Bartoloni A. Recent Imaging Advancements for Lung Metastases in Children with Sarcoma. Curr Med Imaging 2021; 17:236-243. [PMID: 33371858 DOI: 10.2174/1573405616666201228125657] [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: 05/11/2020] [Revised: 11/19/2020] [Accepted: 12/07/2020] [Indexed: 11/22/2022]
Abstract
In children and adolescents affected by musculoskeletal sarcomas (both soft tissue and bone sarcomas), the presence of lung metastases is a frequent complication, that should be known since the patient's prognosis, as management, and treatment depend on it. During the staging phase, the detection of lung metastases should be sensitive and specific, and it should be carried out by minimizing the radiation exposure. To deal with this problem, imaging has reached important goals in recent years, thanks to the development of cone-beam CT or low-dose computed tomography, with some new iterative reconstruction methods, such as Veo and ASIR. Imaging is also fundamental for the possibility to perform lung biopsies under CT guidance, with less morbidity, less time-consumption, and shorter recovery time, compared to surgical biopsies.Moreover, important results have also been demonstrated in the treatment of lung metastases, due to the improvement of new mini-invasive image-guided percutaneous thermal ablation procedures, which proved to be safe and effective also in young patients.
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Affiliation(s)
- Giancarlo Facchini
- Diagnostic and Interventional Radiology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Luca Ceccarelli
- Diagnostic and Interventional Radiology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Paolo Tomà
- Department of Imaging, IRCCS Ospedale Pediatrico Bambino Gesu, Rome, Italy
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Radiologic Assessment of Osteosarcoma Lung Metastases: State of the Art and Recent Advances. Cells 2021; 10:cells10030553. [PMID: 33806513 PMCID: PMC7999261 DOI: 10.3390/cells10030553] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 12/14/2022] Open
Abstract
The lung is the most frequent site of osteosarcoma (OS) metastases, which are a critical point in defining a patient’s prognosis. Chest computed tomography (CT) represents the gold standard for the detection of lung metastases even if its sensitivity widely ranges in the literature since lung localizations are often atypical. ESMO guidelines represent one of the major references for the follow-up program of OS patients. The development of new reconstruction techniques, such as the iterative method and the deep learning-based image reconstruction (DLIR), has led to a significant reduction of the radiation dose with the low-dose CT. The improvement of these techniques has great importance considering the young-onset of the disease and the strict chest surveillance during follow-up programs. The use of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT is still controversial, while volume doubling time (VDT) and computer-aided diagnosis (CAD) systems are recent diagnostic tools that could support radiologists for lung nodules evaluation. Their use, well-established for other malignancies, needs to be further evaluated, focusing on OS patients.
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Image Quality Measured From Ultra-Low Dose Chest Computed Tomography Examination Protocols Using 6 Different Iterative Reconstructions From 4 Vendors, a Phantom Study. J Comput Assist Tomogr 2020; 44:95-101. [DOI: 10.1097/rct.0000000000000947] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ye K, Zhu Q, Li M, Lu Y, Yuan H. A feasibility study of pulmonary nodule detection by ultralow-dose CT with adaptive statistical iterative reconstruction-V technique. Eur J Radiol 2019; 119:108652. [PMID: 31521879 DOI: 10.1016/j.ejrad.2019.108652] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/12/2019] [Accepted: 08/23/2019] [Indexed: 01/22/2023]
Abstract
PURPOSE To evaluate the clinical value of ultralow-dose CT (ULDCT) with adaptive statistical iterative reconstruction-V (ASiR-V) in the detection of pulmonary nodules in a Chinese population. METHOD One hundred eighty-eight patients (16.41 ≤ BMI ≤ 29.87 kg/m2) with pulmonary nodules detected on low-dose chest CT (LDCT) underwent local ULDCT at the center of the chosen nodule with a scan length of 3 cm. LDCT was performed using the Assist kV (120/100 kV)/Smart mA mode and at 120 kV/2.8 mAs for ULDCT. After scanning, CT images were reconstructed with ASiR-V 50%. For both scans, nodule diameters were measured and reference standards were established for the presence and types of lung nodules found on LDCT. The sensitivity of ULDCT was compared against the standard, and logistic regression analysis was used to determine the independent predictors for nodule detection. RESULTS Compared with LDCT (0.93 ± 0.32 mSv), a 89.7% dose decrease was seen with ULDCT, for which the calculated effective dose was 0.096 ± 0.006 mSv (P < 0.001). LDCT showed 188 nodules, including 123 solid and 65 subsolid nodules. The overall sensitivity for nodule detection in ULDCT was 90.4% (170/188), and 98.2% (54/55) for nodules ≥ 6 mm. In multivariate analysis, nodule types and diameters were independent predictors of sensitivity (P < 0.05). However, patients' BMI had no effect on nodule detection (P > 0.05). CONCLUSIONS ULDCT can be used in the management of pulmonary nodules for people with BMI ≤ 30 kg/m2 at 10% radiation dose of LDCT.
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Affiliation(s)
- Kai Ye
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Qiao Zhu
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Meijiao Li
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Yuliu Lu
- Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Huishu Yuan
- Department of Radiology, Peking University Third Hospital, Beijing, China.
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Sun J, Zhang Q, Hu D, Shen Y, Yang H, Chen C, Zhou Z, Peng Y. Feasibility study of using one-tenth mSv radiation dose in young children chest CT with 80 kVp and model-based iterative reconstruction. Sci Rep 2019; 9:12481. [PMID: 31462667 PMCID: PMC6713735 DOI: 10.1038/s41598-019-48946-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 08/16/2019] [Indexed: 01/24/2023] Open
Abstract
CT has become a routine imaging modality based on its excellent ability of displaying lung structures and diseases. But, how to reduce radiation dose of routine CT examination is a concern for radiologists. Our study aimed to evaluate the feasibility of using 80kVp and a model-based iterative reconstruction (MBIR) algorithm to achieve one-tenth mSv dose chest CT in infants and young children. Thirty-two cases (study group, average age 1.71 ± 1.01 years) underwent non-contrast chest CT examination at low dose with 80 kV, 4mAs and was reconstructed with MBIR (LD-MBIR) and the standard adaptive statistical iterative reconstruction (ASIR) algorithm (LD-ASIR); another group (control group) of 32 children underwent routine-dose chest CT with 100 kV and was reconstructed with ASIR only (RD-ASIR). The subjective and objective image quality of the three groups were measured and statistically compared. The radiation dose for the low dose scan was 0.09 ± 0.02 mSv, 6% of the routine dose. All LD-MBIR images were diagnostically acceptable. Compared with the RD-ASIR images, the LD-MBIR images were similar in noise in the left ventricle, muscles, lung field, on-par in displaying large airways, lung lucency and mediastinum, but were inferior in displaying lung marking, small airways and mediastinum. Thus, MBIR images with low dose in pediatric chest CT can be used in the diagnosis for lung field and air way disorders in infants and young children.
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Affiliation(s)
- Jihang Sun
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China
| | - Qifeng Zhang
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China
| | - Di Hu
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China
| | - Yun Shen
- Department of Radiology, Tokyo Women's Medical University &Medical Center East, Tokyo, 116-8567, Japan
| | - Haiming Yang
- Respiratory Department, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China
| | - Chenghao Chen
- Department of Thoracic surgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China
| | - Zuofu Zhou
- Department of radiology, Fujian Provincial Maternity and Children's Hospital, affiliated hospital of Fujian Medical University, No.18 Daoshan Road, Gulou District, Fujian, 350000, China
| | - Yun Peng
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, China.
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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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Zhang L, Chen YF, Che YX, Xu YF, Zheng J, Yu SJ. The impact of adaptive iterative dose reduction 3D on the improvement of shoulder image quality in head and neck CTA. Curr Med Res Opin 2019; 35:887-891. [PMID: 30366505 DOI: 10.1080/03007995.2018.1541446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE The aim of this study was to determine the impact of adaptive iterative dose reduction 3 D (AIDR3D) on the improvement of shoulder image quality in low-radiographic dose head and neck CT angiography (CTA). MATERIALS AND METHODS Ninety patients who underwent CTA examination were randomly divided into two groups, namely group A (n = 45) and B (n = 45). Patients in group A were scanned under 120 kV and 300 mA, with images reconstructed by filtered back projection (FBP), and patients in group B were scanned under 80 kV and auto mA with images reconstructed by AIDR3D. Image quality was accessed by two experienced radiologists. The noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of common carotid artery (CCA) at C7 level, and radiation dosage were compared between the two groups. RESULTS The score of CCA in group B was significantly higher than group A (p < 0.05), and there were no significant differences in the scores of carotid sinus and internal carotid artery between the two groups (p > 0.05). The score of intracranial artery in group B was lower than that of group A, however, the image quality in group B can meet the requirement of clinical diagnosis. The noise value of CCA at C7 level in group B was significantly lower than that of group A (p < 0.05). SNR and CNR values of CCA at C7 level in group B were significantly higher than those of group A (p < 0.05). Effective radiation dose in group B was significantly decreased compared with group A (p < 0.05). CONCLUSION AIDR3D remarkably improved image quality in low-radiographic dose head and neck CTA over FBP, which made the low-dose CTA images meet the requirement of clinical diagnosis.
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Affiliation(s)
- Li Zhang
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
| | - Yue-Feng Chen
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
| | - Yan-Xu Che
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
| | - Yan-Feng Xu
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
| | - Jing Zheng
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
| | - Shu-Jing Yu
- a Department of CT Diagnosis , Cangzhou Central Hospital , Cangzhou , Hebei 061001 , PR China
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High-pitch CT, decreasing need for sedation and its potential side effects: some practical considerations and future directions. Pediatr Radiol 2019; 49:297-300. [PMID: 30535876 DOI: 10.1007/s00247-018-4314-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/26/2018] [Indexed: 12/21/2022]
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Afadzi M, Lysvik EK, Andersen HK, Martinsen ACT. Ultra-low dose chest computed tomography: Effect of iterative reconstruction levels on image quality. Eur J Radiol 2019; 114:62-68. [PMID: 31005179 DOI: 10.1016/j.ejrad.2019.02.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 01/03/2019] [Accepted: 02/16/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To optimize image quality and radiation dose of chest CT with respect to various iterative reconstruction levels, detector collimations and body sizes. METHOD A Kyoto Kagaku Lungman with and without extensions was scanned using fixed ultra-low doses of 0.25, 0.49 and 0.74 mGy CTDIvol, and collimations of 40 and 80 mm. Images were reconstructed with the lung kernel, filtered back projection (FBP) and different ASIR-V levels (10-100%). Contrast-to-noise ratios (CNR) were calculated for 12 mm simulated lesions of different densities in the lung. Image noise, signal-to-noise ratios (SNR), variations in Hounsfield units (HU), noise power spectrum (NPS) and noise texture deviations (NTD) were evaluated for all reconstructions. NTD was calculated as percentage of pixels outside 3 standard deviations to evaluate IR-specific artefacts. RESULTS Compared to the FBP, image noise reduced (5-55%) with ASIR-V levels irrespective of dose or collimation. SNR correlated positively (r ≥ 0.925, p ≤ 0.001) with ASIR-V levels at all doses, collimations, and phantom sizes. ASIR-V enhanced the CNR of the lesion with the lowest contrast from 12.7-42.1 (0-100% ASIR-V) at 0.74 mGy with 40 mm collimation. As expected, higher SNR and CNR were measured in the smaller phantom than the bigger phantom. Uniform HU were observed between FBP and ASIR-V levels at all doses, collimations, and phantom sizes. NPS curves left-shifted towards lower frequencies at increasing levels of ASIR-V irrespective of collimation. A positive correlation (r ≥ 0.946, p ≥ 0.001) was observed between NTD and ASIR-V levels. NTD of the FBP was not significantly (p ≤ 0.087) different from NTD of ASIR-V ≤ 20%. The data from the NPS and NTD indicates a blotchier and coarser noise texture at higher levels of ASIR-V, especially at 100% ASIR-V. CONCLUSION In comparison with the FBP technique, ASIR-V enhanced quantitative image quality parameters at all ultra-low doses tested. Moreover, the use of ASIR-V showed consistency with body size and collimation. Hence, ASIR-V may be useful for improving image quality of chest CT at ultra-low doses.
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Affiliation(s)
- Mercy Afadzi
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway.
| | | | | | - Anne Catrine T Martinsen
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway; The Department of Physics, University of Oslo, Oslo, Norway
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Forward-Projected Model-Based Iterative Reconstruction in Screening Low-Dose Chest CT: Comparison With Adaptive Iterative Dose Reduction 3D. AJR Am J Roentgenol 2018; 211:548-556. [PMID: 30040468 DOI: 10.2214/ajr.17.19245] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The objective of this study is to compare forward-projected model-based iterative reconstruction solution (FIRST), a newer fully iterative CT reconstruction method, with adaptive iterative dose reduction 3D (AIDR 3D) in low-dose screening CT for lung cancer. Differences in image noise, image quality, and pulmonary nodule detection, size, and characterization were specifically evaluated. MATERIALS AND METHODS Low-dose chest CT images obtained for 50 consecutive patients between December 2015 and January 2016 were retrospectively reviewed. Images were reconstructed using FIRST and AIDR 3D for both lung and soft-tissue reconstruction. Images were independently reviewed to assess image noise, subjective image quality (with use of a 5-point Likert scale, with 1 denoting far superior image quality; 2, superior quality; 3, equivalent quality; 4, inferior quality; and 5, far inferior quality), pulmonary nodule count, size of the largest pulmonary nodule, and characterization of the largest pulmonary nodule (i.e., solid, part solid, or ground glass). RESULTS Across all 50 cases, measured image noise was lower with FIRST than with AIDR 3D (lung window, 44% reduction, 41 ± 7 vs 74 ± 8 HU, respectively; soft-tissue window, 32% reduction, 11 ± 2 vs 16 ± 2 HU, respectively). Readers subjectively rated images obtained with FIRST as comparable to images obtained with AIDR 3D (mean [± SD] Likert score for FIRST vs AIDR 3D, 3.2 ± 0.3 for soft-tissue reconstructions and 3.0 ± 0.3 for lung reconstructions). For each reader, very good agreement regarding nodule count was noted between FIRST and AIDR 3D (interclass correlation coefficient [ICC], 0.83 for reader 1 and 0.78 for reader 2). Excellent agreement regarding nodule size (ICC, 0.99 for reader 1 and 0.99 for reader 2) and characterization of the largest nodule (kappa value, 0.92 for reader 1 and 0.82 for reader 2) also existed. CONCLUSION Images reconstructed with FIRST are superior to those reconstructed AIDR 3D with regard to image noise and are equivalent with regard to subjective image quality, pulmonary nodule count, and nodule characterization.
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Qin L, Ma Z, Yan F, Yang W. Iterative model reconstruction (IMR) algorithm for reduced radiation dose renal artery CT angiography with different tube voltage protocols. Radiol Med 2017; 123:83-90. [DOI: 10.1007/s11547-017-0821-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 09/28/2017] [Indexed: 10/18/2022]
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Precht H, Kitslaar PH, Broersen A, Gerke O, Dijkstra J, Thygesen J, Egstrup K, Lambrechtsen J. First experiences with model based iterative reconstructions influence on quantitative plaque volume and intensity measurements in coronary computed tomography angiography. Radiography (Lond) 2016; 23:77-79. [PMID: 28290345 DOI: 10.1016/j.radi.2016.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 08/09/2016] [Accepted: 08/11/2016] [Indexed: 12/14/2022]
Abstract
PURPOSE Investigate the influence of adaptive statistical iterative reconstruction (ASIR) and the model-based IR (Veo) reconstruction algorithm in coronary computed tomography angiography (CCTA) images on quantitative measurements in coronary arteries for plaque volumes and intensities. METHODS Three patients had three independent dose reduced CCTA performed and reconstructed with 30% ASIR (CTDIvol at 6.7 mGy), 60% ASIR (CTDIvol 4.3 mGy) and Veo (CTDIvol at 1.9 mGy). Coronary plaque analysis was performed for each measured CCTA volumes, plaque burden and intensities. RESULTS Plaque volume and plaque burden show a decreasing tendency from ASIR to Veo as median volume for ASIR is 314 mm3 and 337 mm3-252 mm3 for Veo and plaque burden is 42% and 44% for ASIR to 39% for Veo. The lumen and vessel volume decrease slightly from 30% ASIR to 60% ASIR with 498 mm3-391 mm3 for lumen volume and vessel volume from 939 mm3 to 830 mm3. The intensities did not change overall between the different reconstructions for either lumen or plaque. CONCLUSION We found a tendency of decreasing plaque volumes and plaque burden but no change in intensities with the use of low dose Veo CCTA (1.9 mGy) compared to dose reduced ASIR CCTA (6.7 mGy & 4.3 mGy), although more studies are warranted.
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Affiliation(s)
- H Precht
- Odense University Hospital Svendborg, Medical Research Department, Valdemarsgade 53, 5700 Svendborg, Denmark; Conrad Research Center, University College Lillebelt, Niels Bohrs Allé 1, 5230 Odense M, Denmark.
| | - P H Kitslaar
- Leiden University Medical Center, Department of Radiology, Division of Image Processing, Albinusdreef 2, 2300 RC Leiden, The Netherlands; Medis Medical Imaging Systems B.V, Schuttersveld 9, 2300 AJ Leiden, The Netherlands
| | - A Broersen
- Leiden University Medical Center, Department of Radiology, Division of Image Processing, Albinusdreef 2, 2300 RC Leiden, The Netherlands
| | - O Gerke
- Odense University Hospital, Department of Nuclear Medicine, Sdr. Boulevard 29, 5000 Odense C, Denmark; University of Southern Denmark, Centre of Health Economics Research, Campusvej 55, 5230 Odense M, Denmark
| | - J Dijkstra
- Leiden University Medical Center, Department of Radiology, Division of Image Processing, Albinusdreef 2, 2300 RC Leiden, The Netherlands
| | - J Thygesen
- Århus University Hospital, Department of Clinical Engineering, Brendstrupgaardsvej 100, 8200 Århus N, Denmark
| | - K Egstrup
- Odense University Hospital Svendborg, Medical Research Department, Valdemarsgade 53, 5700 Svendborg, Denmark
| | - J Lambrechtsen
- Odense University Hospital Svendborg, Medical Research Department, Valdemarsgade 53, 5700 Svendborg, Denmark
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