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Zhang S, Simard M, Lapointe A, Filion É, Campeau MP, Vu TTT, Roberge D, Carrier JF, Blais D, Bedwani S, Bahig H. Evaluation of Radiation Dose Effect on Lung Function Using Iodine Maps Derived From Dual-Energy Computed Tomography. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00609-6. [PMID: 38705488 DOI: 10.1016/j.ijrobp.2024.04.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/04/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
PURPOSE There is interest in using dual-energy computed tomography (DECT) to evaluate organ function before and after radiation therapy (RT). The purpose of this study (trial identifier: NCT04863027) is to assess longitudinal changes in lung perfusion using iodine maps derived from DECT in patients with lung cancer treated with conventional or stereotactic RT. METHODS AND MATERIALS For 48 prospectively enrolled patients with lung cancer, a contrast-enhanced DECT using a dual-source CT simulator was acquired pretreatment and at 6 and 12 months posttreatment. Pulmonary functions tests (PFT) were obtained at baseline and at 6 and 12 months posttreatment. Iodine maps were extracted from the DECT images using a previously described 2-material decomposition framework. Longitudinal iodine maps were normalized using a reference region defined as all voxels with perfusion in the top 10% outside of the 5 Gy isodose volume. Normalized functional responses (NFR) were calculated for 3 dose ranges: <5, 5 to 20, and >20 Gy. Mixed model analysis was used to assess the correlation between dose metrics and NFR. Pearson correlation was used to assess if NFRs were correlated with PFT changes. RESULTS Out of the 48 patients, 21 (44%) were treated with stereotactic body RT and 27 (56%) were treated with conventionally fractionated intensity-modulated RT. Thirty-one out of these 48 patients were ultimately included in data analysis. It was found that NFR is linearly correlated with dose (P < .001) for both groups. The number of months elapsed post-RT was also found to correlate with NFR (P = .029), although this correlation was not observed for the stereotactic body RT subgroup. The NFR was not found to correlate with PFT changes. CONCLUSIONS DECT-derived iodine maps are a promising method for detailed anatomic evaluation of radiation effect on lung function, including potentially subclinical changes.
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Affiliation(s)
- Shen Zhang
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Mikaël Simard
- Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Département de physique, Université de Montréal, Montréal, Quebec, Canada; Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Andréanne Lapointe
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Édith Filion
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Marie-Pierre Campeau
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Thi Trinh Thuc Vu
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - David Roberge
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Jean-François Carrier
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Département de physique, Université de Montréal, Montréal, Quebec, Canada
| | - Danis Blais
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Stéphane Bedwani
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada; Centre de recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada
| | - Houda Bahig
- Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada.
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Karmali D, Sowho M, Bose S, Pearce J, Tejwani V, Diamant Z, Yarlagadda K, Ponce E, Eikelis N, Otvos T, Khan A, Lester M, Fouras A, Kirkness J, Siddharthan T. Functional imaging for assessing regional lung ventilation in preclinical and clinical research. Front Med (Lausanne) 2023; 10:1160292. [PMID: 37261124 PMCID: PMC10228734 DOI: 10.3389/fmed.2023.1160292] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/17/2023] [Indexed: 06/02/2023] Open
Abstract
Dynamic heterogeneity in lung ventilation is an important measure of pulmonary function and may be characteristic of early pulmonary disease. While standard indices like spirometry, body plethysmography, and blood gases have been utilized to assess lung function, they do not provide adequate information on regional ventilatory distribution nor function assessments of ventilation during the respiratory cycle. Emerging technologies such as xenon CT, volumetric CT, functional MRI and X-ray velocimetry can assess regional ventilation using non-invasive radiographic methods that may complement current methods of assessing lung function. As a supplement to current modalities of pulmonary function assessment, functional lung imaging has the potential to identify respiratory disease phenotypes with distinct natural histories. Moreover, these novel technologies may offer an optimal strategy to evaluate the effectiveness of novel therapies and therapies targeting localized small airways disease in preclinical and clinical research. In this review, we aim to discuss the features of functional lung imaging, as well as its potential application and limitations to adoption in research.
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Affiliation(s)
- Dipan Karmali
- Division of Pulmonary and Critical Care, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
| | - Mudiaga Sowho
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Sonali Bose
- Division of Pulmonary and Critical Care, Icahn School of Medicine, Mount Sinai, NY, United States
| | - Jackson Pearce
- School of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Vickram Tejwani
- Respiratory Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Zuzana Diamant
- Department of Microbiology Immunology and Transplantation, KU Leuven, Catholic University of Leuven, Leuven, Belgium
- Department of Respiratory Medicine and Allergology, Institute for Clinical Science, Skane University Hospital, Lund University, Lund, Sweden
- Department Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Keerthi Yarlagadda
- Division of Pulmonary and Critical Care, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
| | - Erick Ponce
- Division of Pulmonary and Critical Care, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
| | | | | | - Akram Khan
- Division of Pulmonary and Critical Care, Oregon Health and Science University, Portland, OR, United States
| | - Michael Lester
- Department of Pulmonary and Critical Care Medicine, Vanderbilt Medical Center, Nashville, CA, United States
| | | | | | - Trishul Siddharthan
- Division of Pulmonary and Critical Care, Leonard M. Miller School of Medicine, University of Miami, Coral Gables, FL, United States
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3
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Gaudreault M, Korte J, Bucknell N, Jackson P, Sakyanun P, McIntosh L, Woon B, Buteau JP, Hofman MS, Mulcahy T, Kron T, Siva S, Hardcastle N. Comparison of dual-energy CT with positron emission tomography for lung perfusion imaging in patients with non-small cell lung cancer. Phys Med Biol 2023; 68. [PMID: 36623318 DOI: 10.1088/1361-6560/acb198] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 01/09/2023] [Indexed: 01/11/2023]
Abstract
Objective.Functional lung avoidance (FLA) radiotherapy treatment aims to spare lung regions identified as functional from imaging. Perfusion contributes to lung function and can be measured from the determination of pulmonary blood volume (PBV). An advantageous alternative to the current determination of PBV from positron emission tomography (PET) may be from dual energy CT (DECT), due to shorter examination time and widespread availability. This study aims to determine the correlation between PBV determined from DECT and PET in the context of FLA radiotherapy.Approach.DECT and PET acquisitions at baseline of patients enrolled in the HI-FIVE clinical trial (ID: NCT03569072) were reviewed. Determination of PBV from PET imaging (PBVPET), from DECT imaging generated from a commercial software (Syngo.via, Siemens Healthineers, Forchheim, Germany) with its lowest (PBVsyngoR=1) and highest (PBVsyngoR=10) smoothing level parameter value (R), and from a two-material decomposition (TMD) method (PBVTMDL) with variable median filter kernel size (L) were compared. Deformable image registration between DECT images and the CT component of the PET/CT was applied to PBV maps before resampling to the PET resolution. The Spearman correlation coefficient (rs) between PBV determinations was calculated voxel-wise in lung subvolumes.Main results.Of this cohort of 19 patients, 17 had a DECT acquisition at baseline. PBV maps determined from the commercial software and the TMD method were very strongly correlated [rs(PBVsyngoR=1,PBVTMDL=1) = 0.94 ± 0.01 andrs(PBVsyngoR=10,PBVTMDL=9) = 0.94 ± 0.02].PBVPETwas strongly correlated withPBVTMDL[rs(PBVPET,PBVTMDL=28) = 0.67 ± 0.11]. Perfusion patterns differed along the posterior-anterior direction [rs(PBVPET,PBVTMDL=28) = 0.77 ± 0.13/0.57 ± 0.16 in the anterior/posterior region].Significance. A strong correlation between DECT and PET determination of PBV was observed. Streak and smoothing effects in DECT and gravitational artefacts and misregistration in PET reduced the correlation posteriorly.
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Affiliation(s)
- Mathieu Gaudreault
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia
| | - James Korte
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Department of Biomedical Engineering, School of Chemical and Biomedical Engineering, University of Melbourne, Melbourne, Victoria, Australia
| | - Nicholas Bucknell
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Price Jackson
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia
| | - Pitchaya Sakyanun
- Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Department of Radiation Oncology, Phramongkutklao Hospital, Bangkok, Thailand
| | - Lachlan McIntosh
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Beverley Woon
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - James P Buteau
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Molecular Imaging and Therapeutic Nuclear Medicine; Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC) , Peter MacCallum Cancer Centre, Melbourne, Victoria, 3000, Australia
| | - Michael S Hofman
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Molecular Imaging and Therapeutic Nuclear Medicine; Prostate Cancer Theranostics and Imaging Centre of Excellence (ProsTIC) , Peter MacCallum Cancer Centre, Melbourne, Victoria, 3000, Australia
| | - Tony Mulcahy
- Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Tomas Kron
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Centre for Medical Radiation Physics, University of Wollongong, NSW, 2522, Australia
| | - Shankar Siva
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Nicholas Hardcastle
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia.,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3000, Australia.,Centre for Medical Radiation Physics, University of Wollongong, NSW, 2522, Australia
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4
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Zhou PX, Zhang SX. Functional lung imaging in thoracic tumor radiotherapy: Application and progress. Front Oncol 2022; 12:908345. [PMID: 36212454 PMCID: PMC9544588 DOI: 10.3389/fonc.2022.908345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/17/2022] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy plays an irreplaceable and unique role in treating thoracic tumors, but the occurrence of radiation-induced lung injury has limited the increase in tumor target doses and has influenced patients’ quality of life. However, the introduction of functional lung imaging has been incorporating functional lungs into radiotherapy planning. The design of the functional lung protection plan, while meeting the target dose requirements and dose limitations of the organs at risk (OARs), minimizes the radiation dose to the functional lung, thus reducing the occurrence of radiation-induced lung injury. In this manuscript, we mainly reviewed the lung ventilation or/and perfusion functional imaging modalities, application, and progress, as well as the results based on the functional lung protection planning in thoracic tumors. In addition, we also discussed the problems that should be explored and further studied in the practical application based on functional lung radiotherapy planning.
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Affiliation(s)
- Pi-Xiao Zhou
- Radiotherapy Center, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China
- Department of Oncology, The First People's Hospital of Changde City, Changde, China
| | - Shu-Xu Zhang
- Radiotherapy Center, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China
- *Correspondence: Shu-Xu Zhang,
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5
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Lyhne MD, Witkin AS, Dasegowda G, Tanayan C, Kalra MK, Dudzinski DM. Evaluating cardiopulmonary function following acute pulmonary embolism. Expert Rev Cardiovasc Ther 2022; 20:747-760. [PMID: 35920239 DOI: 10.1080/14779072.2022.2108789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
INTRODUCTION Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation. AREAS COVERED In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism. EXPERT OPINION Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.
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Affiliation(s)
- Mads Dam Lyhne
- Department of Cardiology, Massachusetts General Hospital, Boston, MA, USA.,Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Denmark
| | - Alison S Witkin
- Department of Pulmonary Medicine and Critical Care, Massachusetts General Hospital, Boston, MA, USA
| | - Giridhar Dasegowda
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Christopher Tanayan
- Cardiovascular Performance Program, Massachusetts General Hospital, Boston, MA, USA
| | - Mannudeep K Kalra
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - David M Dudzinski
- Department of Cardiology, Massachusetts General Hospital, Boston, MA, USA.,Echocardiography Laboratory, Massachusetts General Hospital, Boston, MA, USA
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6
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Vulasala SSR, Wynn GC, Hernandez M, Kadambi I, Gopireddy DR, Bhosale P, Virarkar MK. Dual-Energy Imaging of the Chest. Semin Ultrasound CT MR 2022; 43:311-319. [PMID: 35738816 DOI: 10.1053/j.sult.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy computed tomography (DECT) is a contemporary development by which the tissue can be characterized beyond conventional computed tomography. It improves tissue differentiation by exploiting the X-ray absorptive property of the tissues. Although still in its early stages, DECT utilization in pulmonary and cardiovascular pathologies is emerging. It includes applications such as pulmonary embolism, pulmonary hypertension, myocardial perfusion, and coronary artery assessment. This article discusses DECT principles and their current and emerging applications in thoracic imaging.
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Affiliation(s)
- Sai Swarupa R Vulasala
- Research Assistant, Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States
| | - Gregory Carl Wynn
- Associate Professor, Division of Cardiovascular and Thoracic Imaging, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States
| | - Mauricio Hernandez
- Radiology Research Manager II, Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States.
| | - Isiri Kadambi
- Observer, Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States
| | - Dheeraj Reddy Gopireddy
- Associate Professor & Associate Chair, Clinical Operations, and Quality Assurance., Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States
| | - Priya Bhosale
- Professor, Department of Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas, 77030, United States
| | - Mayur K Virarkar
- Assistant Professor, Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida, 32209, United States
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7
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Wang Y, Yan WQ. Colorizing Grayscale CT images of human lungs using deep learning methods. MULTIMEDIA TOOLS AND APPLICATIONS 2022; 81:37805-37819. [PMID: 35475169 PMCID: PMC9027015 DOI: 10.1007/s11042-022-13062-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/20/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Image colorization refers to computer-aided rendering technology which transfers colors from a reference color image to grayscale images or video frames. Deep learning elevated notably in the field of image colorization in the past years. In this paper, we formulate image colorization methods relying on exemplar colorization and automatic colorization, respectively. For hybrid colorization, we select appropriate reference images to colorize the grayscale CT images. The colours of meat resemble those of human lungs, so the images of fresh pork, lamb, beef, and even rotten meat are collected as our dataset for model training. Three sets of training data consisting of meat images are analysed to extract the pixelar features for colorizing lung CT images by using an automatic approach. Pertaining to the results, we consider numerous methods (i.e., loss functions, visual analysis, PSNR, and SSIM) to evaluate the proposed deep learning models. Moreover, compared with other methods of colorizing lung CT images, the results of rendering the images by using deep learning methods are significantly genuine and promising. The metrics for measuring image similarity such as SSIM and PSNR have satisfactory performance, up to 0.55 and 28.0, respectively. Additionally, the methods may provide novel ideas for rendering grayscale X-ray images in airports, ferries, and railway stations.
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Affiliation(s)
- Yuewei Wang
- Auckland University of Technology, Auckland, 1010 New Zealand
| | - Wei Qi Yan
- Auckland University of Technology, Auckland, 1010 New Zealand
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8
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Charyyev S, Wang T, Lei Y, Ghavidel B, Beitler JJ, McDonald M, Curran WJ, Liu T, Zhou J, Yang X. Learning-based synthetic dual energy CT imaging from single energy CT for stopping power ratio calculation in proton radiation therapy. Br J Radiol 2022; 95:20210644. [PMID: 34709948 PMCID: PMC8722254 DOI: 10.1259/bjr.20210644] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Dual energy CT (DECT) has been shown to estimate stopping power ratio (SPR) map with a higher accuracy than conventional single energy CT (SECT) by obtaining the energy dependence of photon interactions. This work presents a learning-based method to synthesize DECT images from SECT image for proton radiotherapy. METHODS The proposed method uses a residual attention generative adversarial network. Residual blocks with attention gates were used to force the model to focus on the difference between DECT images and SECT images. To evaluate the accuracy of the method, we retrospectively investigated 70 head-and-neck cancer patients whose DECT and SECT scans were acquired simultaneously. The model was trained to generate both a high and low energy DECT image based on a SECT image. The generated synthetic low and high DECT images were evaluated against the true DECT images using leave-one-out cross-validation. To evaluate our method in the context of a practical application, we generated SPR maps from synthetic DECT (sDECT) using a dual-energy based stoichiometric method and compared the SPR maps to those generated from DECT. A dosimetric comparison for dose obtained from DECT was performed against that derived from sDECT. RESULTS The mean of mean absolute error, peak signal-to-noise ratio and normalized cross-correlation for the synthetic high and low energy CT images was 36.9 HU, 29.3 dB, 0.96 and 35.8 HU, 29.2 dB, and 0.96, respectively. The corresponding SPR maps generated from synthetic DECT showed an average normalized mean square deviation of about 1% with reduced noise level and artifacts than those from original DECT. Dose-volume histogram (DVH) metrics for the clinical target volume agree within 1% between the DECT and sDECT calculated dose. CONCLUSION Our method synthesized accurate DECT images and showed a potential feasibility for proton SPR map generation. ADVANCES IN KNOWLEDGE This study investigated a learning-based method to synthesize DECT images from SECT image for proton radiotherapy.
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Affiliation(s)
- Serdar Charyyev
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Tonghe Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Yang Lei
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Beth Ghavidel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Jonathan J Beitler
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Mark McDonald
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Walter J Curran
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, USA
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9
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Degerstedt SG, Winant AJ, Lee EY. Pediatric Pulmonary Embolism: Imaging Guidelines and Recommendations. Radiol Clin North Am 2021; 60:69-82. [PMID: 34836567 DOI: 10.1016/j.rcl.2021.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In contrast with the algorithms and screening criteria available for adults with suspected pulmonary embolism, there is a paucity of guidance on the diagnostic approach for children. The incidence of pulmonary embolism in the pediatric population and young adults is higher than thought, and there is an urgent need for updated guidelines for the imaging approach to diagnosis in the pediatric population. This article presents an up-to-date review of imaging techniques, characteristic radiologic findings, and an evidence-based algorithm for the detection of pediatric pulmonary embolism to improve the care of pediatric patients with suspected pulmonary embolism.
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Affiliation(s)
- Spencer G Degerstedt
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Abbey J Winant
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Edward Y Lee
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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10
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Hong YJ, Shim J, Lee SM, Im DJ, Hur J. Dual-Energy CT for Pulmonary Embolism: Current and Evolving Clinical Applications. Korean J Radiol 2021; 22:1555-1568. [PMID: 34448383 PMCID: PMC8390816 DOI: 10.3348/kjr.2020.1512] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/22/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022] Open
Abstract
Pulmonary embolism (PE) is a potentially fatal disease if the diagnosis or treatment is delayed. Currently, multidetector computed tomography (MDCT) is considered the standard imaging method for diagnosing PE. Dual-energy CT (DECT) has the advantages of MDCT and can provide functional information for patients with PE. The aim of this review is to present the potential clinical applications of DECT in PE, focusing on the diagnosis and risk stratification of PE.
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Affiliation(s)
- Yoo Jin Hong
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jina Shim
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Min Lee
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Dong Jin Im
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jin Hur
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
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11
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Afat S, Othman AE, Nikolaou K, Gassenmaier S. Dual-Energy Computed Tomography of the Lung in COVID-19 Patients: Mismatch of Perfusion Defects and Pulmonary Opacities. Diagnostics (Basel) 2020; 10:E870. [PMID: 33114478 PMCID: PMC7693945 DOI: 10.3390/diagnostics10110870] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/14/2020] [Accepted: 10/23/2020] [Indexed: 01/08/2023] Open
Abstract
To evaluate contrast-enhanced dual-energy computed tomography (DECT) chest examinations regarding pulmonary perfusion patterns and pulmonary opacities in patients with confirmed COVID-19 disease. Fourteen patients with 24 DECT examinations performed between April and May 2020 were included in this retrospective study. DECT studies were assessed independently by two radiologists regarding pulmonary perfusion defects, using a Likert scale ranging from 1 to 4. Furthermore, in all imaging studies the extent of pulmonary opacities was quantified using the same rating system as for perfusion defects. The main pulmonary findings were ground glass opacities (GGO) in all 24 examinations and pulmonary consolidations in 22 examinations. The total lung scores after the addition of the scores of the single lobes showed significantly higher values of opacities compared to perfusion defects, with a median of 12 (9-18) for perfusion defects and a median of 17 (15-19) for pulmonary opacities (p = 0.002). Furthermore, mosaic perfusion patterns were found in 19 examinations in areas with and without GGO. Further studies will be necessary to investigate the pathophysiological background of GGO with maintained perfusion compared to GGO with reduced perfusion, especially regarding long-term lung damage and prognosis.
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Affiliation(s)
| | - Ahmed E. Othman
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tuebingen, 72076 Tuebingen, Germany; (S.A.); (K.N.); (S.G.)
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Santamarina MG, Boisier Riscal D, Beddings I, Contreras R, Baque M, Volpacchio M, Martinez Lomakin F. COVID-19: What Iodine Maps From Perfusion CT can reveal-A Prospective Cohort Study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:619. [PMID: 33087155 PMCID: PMC7576979 DOI: 10.1186/s13054-020-03333-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/06/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Subtraction CT angiography (sCTA) is a technique used to evaluate pulmonary perfusion based on iodine distribution maps. The aim of this study is to assess lung perfusion changes with sCTA seen in patients with COVID-19 pneumonia and correlate them with clinical outcomes. MATERIAL AND METHODS A prospective cohort study was carried out with 45 RT-PCR-confirmed COVID-19 patients that required hospitalization at three different hospitals, between April and May 2020. In all cases, a basic clinical and demographic profile was obtained. Lung perfusion was assessed using sCTA. Evaluated imaging features included: Pattern predominance of injured lung parenchyma in both lungs (ground-glass opacities, consolidation and mixed pattern) and anatomical extension; predominant type of perfusion abnormality (increased perfusion or hypoperfusion), perfusion abnormality distribution (focal or diffuse), extension of perfusion abnormalities (mild, moderate and severe involvement); presence of vascular dilatation and vascular tortuosity. All participants were followed-up until hospital discharge searching for the development of any of the study endpoints. These endpoints included intensive-care unit (ICU) admission, initiation of invasive mechanical ventilation (IMV) and death. RESULTS Forty-one patients (55.2 ± 16.5 years, 22 men) with RT-PCR-confirmed SARS-CoV-2 infection and an interpretable iodine map were included. Patients with perfusion anomalies on sCTA in morphologically normal lung parenchyma showed lower Pa/Fi values (294 ± 111.3 vs. 397 ± 37.7, p = 0.035), and higher D-dimer levels (1156 ± 1018 vs. 378 ± 60.2, p < 0.01). The main common patterns seen in lung CT scans were ground-glass opacities, mixed pattern with predominant ground-glass opacities and mixed pattern with predominant consolidation in 56.1%, 24.4% and 19.5% respectively. Perfusion abnormalities were common (36 patients, 87.8%), mainly hypoperfusion in areas of apparently healthy lung. Patients with severe hypoperfusion in areas of apparently healthy lung parenchyma had an increased probability of being admitted to ICU and to initiate IMV (HR of 11.9 (95% CI 1.55-91.9) and HR 7.8 (95% CI 1.05-61.1), respectively). CONCLUSION Perfusion abnormalities evidenced in iodine maps obtained by sCTA are associated with increased admission to ICU and initiation of IMV in COVID-19 patients.
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Affiliation(s)
- Mario G Santamarina
- Radiology Department, Hospital Naval Almirante Nef, Subida Alesandri S/N., Viña del Mar, Provincia de Valparaíso, Chile. .,Radiology Department, Hospital Dr. Eduardo Pereira, Valparaiso, Chile.
| | | | | | - Roberto Contreras
- Intensive Care Unit, Hospital San Martin de Quillota, Quillota, Chile
| | - Martiniano Baque
- Intensive Care Unit, Hospital IESS Los Ceibos, Guayaquil, Ecuador
| | - Mariano Volpacchio
- Radiology Department, Centro de Diagnóstico Dr. Enrique Rossi, Buenos Aires, Argentina
| | - Felipe Martinez Lomakin
- Intensive Care Unit, Hospital Naval Almirante Nef, Viña del Mar, Chile.,Viña del Mar, Escuela de Medicina, Facultad de Medicina Viña del Mar, Universidad Andres Bello, Valparaiso, Chile
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Grillet F, Busse-Coté A, Calame P, Behr J, Delabrousse E, Aubry S. COVID-19 pneumonia: microvascular disease revealed on pulmonary dual-energy computed tomography angiography. Quant Imaging Med Surg 2020; 10:1852-1862. [PMID: 32879862 PMCID: PMC7417764 DOI: 10.21037/qims-20-708] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 06/19/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Increased prevalence of acute pulmonary embolism in COVID-19 has been reported in few recent studies. Some works have highlighted pathological changes on lung microvasculature with local pulmonary intravascular coagulopathy that may explain pulmonary artery thrombosis found on pulmonary computed tomography (CT) angiography. The objective of our study was to describe lung perfusion disorders assessed by pulmonary dual-energy CT (DECT) angiography in severe COVID-19 patients. METHODS This single center retrospective study included 85 consecutive patients with a reverse transcriptase-polymerase chain reaction diagnosis of SARS-CoV-2 who underwent a pulmonary DECT angiography between March 16th 2020 and April 22th 2020. Pulmonary DECT angiography was performed when the patient had severe clinical symptoms or suffered from active neoplasia or immunosuppression. Two chest radiologists performed pulmonary angiography analysis in search of pulmonary artery thrombosis and a blinded semi quantitative analysis of iodine color maps focusing on the presence of parenchymal ischemia. The lung parenchyma was divided into volumes based on HU values. DECT analysis included lung segmentation, total lungs volume and distribution of lung perfusion assessment. RESULTS Twenty-nine patients (34%) were diagnosed with pulmonary artery thrombosis, mainly segmental (83%). Semi-quantitative analysis revealed parenchymal ischemia in 68% patients of the overall population, with no significant difference regarding absence or presence of pulmonary artery thrombosis (23 vs. 35, P=0.144). Inter-reader agreement of parenchymal ischemia between reader 1 and 2 was substantial [0.74; interquartile range (IQR): 0.59-0.89]. Volume of ischemia was significantly higher in patients with pulmonary artery thrombosis [29 (IQR, 8-100) vs. 8 (IQR, 0-45) cm3, P=0.041]. Lung parenchyma was divided between normal parenchyma (59%, of which 34% was hypoperfused), ground glass opacities (10%, of which 20% was hypoperfused) and consolidation (31%, of which 10% was hypoperfused). CONCLUSIONS Pulmonary perfusion evaluated by iodine concentration maps shows extreme heterogeneity in COVID-19 patients and lower iodine levels in normal parenchyma. Pulmonary ischemic areas were more frequent and larger in patients with pulmonary artery thrombosis. Pulmonary DECT angiography revealed a significant number of pulmonary ischemic areas even in the absence of visible pulmonary arterial thrombosis. This may reflect microthrombosis associated with COVID-19 pneumonia.
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Affiliation(s)
- Franck Grillet
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
| | - Andreas Busse-Coté
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
| | - Paul Calame
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
| | - Julien Behr
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
| | - Eric Delabrousse
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
- Nanomedecine Laboratory EA4662, University of Franche-Comte, Besancon, France
| | - Sébastien Aubry
- Department of Radiology, Centre Hospitalier Universitaire de Besancon, Besancon, France
- Nanomedecine Laboratory EA4662, University of Franche-Comte, Besancon, France
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Pulmonary perfusion by iodine subtraction maps CT angiography in acute pulmonary embolism: comparison with pulmonary perfusion SPECT (PASEP trial). Eur Radiol 2020; 30:4857-4864. [PMID: 32279113 DOI: 10.1007/s00330-020-06836-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/03/2020] [Accepted: 03/25/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To assess the diagnostic accuracy of iodine map computed tomography pulmonary angiography (CTPA), for segment-based evaluation of lung perfusion in patients with acute pulmonary embolism (PE), using perfusion single-photon emission CT (SPECT) imaging as a reference standard. METHODS Thirty participants who have been diagnosed with acute pulmonary embolism on CTPA underwent perfusion SPECT/CT within 24 h. Perfusion SPECT and iodine map were independently interpreted by 2 nuclear medicine physicians and 2 radiologists. For both modalities, each segment was classified as normoperfused or hypoperfused, as defined by a perfusion defect of more than 25% of a segment. The primary end point was the diagnostic accuracy (sensitivity and specificity) of iodine map for segment-based evaluation of lung perfusion, using perfusion SPECT imaging as a reference standard. Following blinded interpretation, a retrospective explanatory analysis was performed to determine potential causes of misinterpretation. RESULTS The median time between CTPA with iodine maps and perfusion SPECT was 14 h (range 2-23 h). A total of 597 segments were analyzed. Sensitivity and specificity of iodine maps with CTPA for the detection of segmental perfusion defects were 231/284 = 81.3% (95% CI 76.4 to 85.4%) and 247/313 = 78.9% (95% CI 74.1 to 83.1%), respectively. In retrospect, false results were explained in 48.7%. CONCLUSION Iodine map CTPA showed promising results for the assessment of pulmonary perfusion in patients with acute PE, with sensitivity of 81.3% and specificity of 78.9%, respectively. Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the accuracy of the test. KEY POINTS • Sensitivity and specificity of iodine subtraction maps for the detection of segmental perfusion defects were 81.3% (95% CI 76.4 to 85.4%) and 78.9% (95% CI 74.1 to 83.1%), respectively. • Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the diagnostic accuracy of the test.
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Acquisition time, radiation dose, subjective and objective image quality of dual-source CT scanners in acute pulmonary embolism: a comparative study. Eur Radiol 2020; 30:2712-2721. [PMID: 32025830 DOI: 10.1007/s00330-019-06650-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/04/2019] [Accepted: 12/19/2019] [Indexed: 01/08/2023]
Abstract
OBJECTIVES To compare the scan acquisition time, radiation dose, subjective and objective image quality of two dual-source CT scanners (DSCT) for detection of acute pulmonary embolism. METHODS Two hundred twenty-one scans performed on the 2nd-generation DSCT and 354 scans on the 3rd-generation DSCT were included in this large retrospective study. In a randomized blinded design, two radiologists independently reviewed the scans using a 5-point Likert scale. Radiation dose and objective image quality parameters were calculated. RESULTS Mean acquisition time was significantly lower in the 3rd-generation DSCT (2.81 s ± 0.1 in comparison with 9.7 s ± 0.15 [mean ± SD] respectively; p < 0.0001) with the 3rd generation 3.4 times faster. The mean subjective image quality score was 4.33/5 and 4/5 for the 3rd- and 2nd-generation DSCT respectively (p < 0.0001) with strong interobserver reliability agreement. DLP, CTDIvol, and ED were significantly lower in the 3rd than the 2nd generation (175.6 ± 63.7 mGy cm; 5.3 ± 1.9 mGy and 2.8 ± 1.2 mSv in comparison with 266 ± 255 mGy.cm; 7.8 ± 2.2 mGy and 3.8 ± 4.3 mSv). Noise was significantly lower in the 3rd generation (p < 0.01). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM), a dose-insensitive index for CNR, were significantly higher in the 3rd-generation DSCT (33.5 ± 23.4; 29.0 ± 21.3 and 543.7 ± 1037 in comparison with 23.4 ± 17.7; 19.4 ± 16.0 and 170.5 ± 284.3). CONCLUSION Objective and subjective image quality are significantly higher on the 3rd-generation DSCT with significantly lower mean acquisition time and radiation dose. KEY POINTS • The 3rd-generation DSCT scanner provides an improved image quality, less perceived artifacts, and lower radiation dose in comparison with the 2nd-generation DSCT, when operating in dual-energy (DE) mode. • The 3.4-times-faster 3rd-generation DSCT scanner can be of particular value in patients with chronic lung diseases or breathing difficulties that prevent adequate breathhold.
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Singh R, Nie RZ, Homayounieh F, Schmidt B, Flohr T, Kalra MK. Quantitative lobar pulmonary perfusion assessment on dual-energy CT pulmonary angiography: applications in pulmonary embolism. Eur Radiol 2020; 30:2535-2542. [DOI: 10.1007/s00330-019-06607-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/25/2019] [Accepted: 12/04/2019] [Indexed: 11/25/2022]
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Komolafe TE, Zhang C, Li M, Du Q, Zheng J, Yang X. Hybrid Optimization Method (HOM) Reconstruction with limited angle in Dual Energy Breast CT. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:4875-4880. [PMID: 31946953 DOI: 10.1109/embc.2019.8857376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Limited angle Breast Computed Tomography uses lower energy and low projection angle to detect early breast cancer or other malignant tissues in the breast. The sensitivity of breast CT can be improved by applying dual energy technology. The general challenge which hampers full exploration of dual energy imaging is noise accumulation as a result of spectral overlaps from two different images. The author proposed hybrid optimization method (HOM) which leverages on fast convergence of simultaneous algebraic reconstruction techniques (SART) and good de-noising and artefacts removal of dictionary learning (DL) to minimizes noise in each image of dual energy and then apply decomposition on the noiseless dual data. The HOM algorithm is formulated as optimization problem which find good atoms from the dictionary obtained and dictionary atom are learned from training data set. The reconstructed images which are noise-free are then decomposed using DECT algorithm into two material basis. 2D phantom known as mbat-phantom consisting of two material basis (microcalcification and normal breast tissue) were simulated to test the algorithm. Noisy projection data were also simulated under the same condition by adding poison noise. The performance of the method was evaluated by estimating some image quality indices on reconstructed images and decomposed images. The proposed method shows the highest average structural similarity index map (SSIM) of 0.9987 and 0.9921 and peak signal to-noise ratio (PSNR) of 49.24 and 46.96 for reconstructed image without noise and noisy image respectively. Also, there is a reduction in average standard deviation (STD) error of decomposed image. Our method performs excellently in streak artefact removal and noise suppression which is capable of reconstructing faithful image in presence of noisy data.
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Grob D, Smit E, Prince J, Kist J, Stöger L, Geurts B, Snoeren MM, van Dijk R, Oostveen LJ, Prokop M, Schaefer-Prokop CM, Sechopoulos I, Brink M. Iodine Maps from Subtraction CT or Dual-Energy CT to Detect Pulmonary Emboli with CT Angiography: A Multiple-Observer Study. Radiology 2019; 292:197-205. [DOI: 10.1148/radiol.2019182666] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dagmar Grob
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Ewoud Smit
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Jip Prince
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Jakob Kist
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Lauran Stöger
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Bram Geurts
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Miranda M. Snoeren
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Rogier van Dijk
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Luuk J. Oostveen
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Mathias Prokop
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Cornelia M. Schaefer-Prokop
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Ioannis Sechopoulos
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
| | - Monique Brink
- From the Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands (D.G., E.S., B.G., M.M.S., L.L.O., M.P., I.S., M.B.); and Department of Radiology and Nuclear Medicine, Meander Medical Centre, Amersfoort, the Netherlands (J.P., J.K., L.S., R.v.D., C.M.S.P.)
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Young HM, Eddy RL, Parraga G. MRI and CT lung biomarkers: Towards an in vivo understanding of lung biomechanics. Clin Biomech (Bristol, Avon) 2019; 66:107-122. [PMID: 29037603 DOI: 10.1016/j.clinbiomech.2017.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/22/2017] [Accepted: 09/27/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND The biomechanical properties of the lung are necessarily dependent on its structure and function, both of which are complex and change over time and space. This makes in vivo evaluation of lung biomechanics and a deep understanding of lung biomarkers, very challenging. In patients and animal models of lung disease, in vivo evaluations of lung structure and function are typically made at the mouth and include spirometry, multiple-breath gas washout tests and the forced oscillation technique. These techniques, and the biomarkers they provide, incorporate the properties of the whole organ system including the parenchyma, large and small airways, mouth, diaphragm and intercostal muscles. Unfortunately, these well-established measurements mask regional differences, limiting their ability to probe the lung's gross and micro-biomechanical properties which vary widely throughout the organ and its subcompartments. Pulmonary imaging has the advantage in providing regional, non-invasive measurements of healthy and diseased lung, in vivo. Here we summarize well-established and emerging lung imaging tools and biomarkers and how they may be used to generate lung biomechanical measurements. METHODS We review well-established and emerging lung anatomical, microstructural and functional imaging biomarkers generated using synchrotron x-ray tomographic-microscopy (SRXTM), micro-x-ray computed-tomography (micro-CT), clinical CT as well as magnetic resonance imaging (MRI). FINDINGS Pulmonary imaging provides measurements of lung structure, function and biomechanics with high spatial and temporal resolution. Imaging biomarkers that reflect the biomechanical properties of the lung are now being validated to provide a deeper understanding of the lung that cannot be achieved using measurements made at the mouth.
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Affiliation(s)
- Heather M Young
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Rachel L Eddy
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Grace Parraga
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada; Graduate Program in Biomedical Engineering, Western University, London, Canada.
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Sauter AP, Hammel J, Ehn S, Achterhold K, Kopp FK, Kimm MA, Mei K, Laugerette A, Pfeiffer F, Rummeny EJ, Pfeiffer D, Noël PB. Perfusion-ventilation CT via three-material differentiation in dual-layer CT: a feasibility study. Sci Rep 2019; 9:5837. [PMID: 30967601 PMCID: PMC6456734 DOI: 10.1038/s41598-019-42330-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 03/28/2019] [Indexed: 01/30/2023] Open
Abstract
Dual-Energy Computed Tomography is of significant clinical interest due to the possibility of material differentiation and quantification. In current clinical routine, primarily two materials are differentiated, e.g., iodine and soft-tissue. A ventilation-perfusion-examination acquired within a single CT scan requires two contrast agents, e.g., xenon and gadolinium, and a three-material differentiation. In the current study, we have developed a solution for three-material differentiation for a ventilation-perfusion-examination. A landrace pig was examined using a dual-layer CT, and three scans were performed: (1) native; (2) xenon ventilation only; (3) xenon ventilation and gadolinium perfusion. An in-house developed algorithm was used to obtain xenon- and gadolinium-density maps. Firstly, lung tissue was segmented from other tissue. Consequently, a two-material decomposition was performed for lung tissue (xenon/soft-tissue) and for remaining tissue (gadolinium/soft-tissue). Results reveal that it was possible to differentiate xenon and gadolinium in a ventilation/perfusion scan of a pig, resulting in xenon and gadolinium density maps. By summation of both density maps, a three-material differentiation (xenon/gadolinium/soft tissue) can be performed and thus, xenon ventilation and gadolinium perfusion can be visualized in a single CT scan. In an additionally performed phantom study, xenon and gadolinium quantification showed very accurate results (r > 0.999 between measured and known concentrations).
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Affiliation(s)
- Andreas P Sauter
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany.
| | - Johannes Hammel
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Sebastian Ehn
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Klaus Achterhold
- Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, Germany
| | - Felix K Kopp
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Melanie A Kimm
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Kai Mei
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Alexis Laugerette
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany.,Chair of Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Garching, Germany.,Institute for Advanced Study, Technical University of Munich, Garching, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Peter B Noël
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
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Spectral CT and its specific values in the staging of patients with non-small cell lung cancer: technical possibilities and clinical impact. Clin Radiol 2019; 74:456-466. [PMID: 30905380 DOI: 10.1016/j.crad.2019.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 02/12/2019] [Indexed: 12/25/2022]
Abstract
AIM To investigate how spectral computed tomography (SCT) values impact the staging of non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS One hundred and thirteen patients with confirmed NSCLC were included in a prospective cohort study. All patients underwent single-phase contrast-enhanced SCT (using the fast tube voltage switching technique, 80-140 kV). SCT values (iodine content [IC], spectral slope pitch, and radiodensity increase) of malignant tissue (primary and metastases) and lymph nodes (LNs) were measured. Adrenal masses were evaluated in a virtual non-contrast series (VNS). If pulmonary embolism was present, pulmonary perfusion was analysed as an additional finding. RESULTS Fifty-two untreated primary NSCLC lesions were evaluable. Lung adenocarcinoma had significantly higher normalised IC (NIC: 19.37) than squamous cell carcinoma (NIC: 12.03; p=0.035). Pulmonary metastases were not significantly different from benign lung nodules. A total of 126 LNs were analysed and histologically proven metastatic LNs (2.08 mg/ml) had significantly lower IC than benign LNs (2.58 mg/ml; p=0.023). Among 34 adrenal masses, VNS identified adenomas with high sensitivity (91%) and specificity (100%). In two patients, a perfusion defect due to pulmonary embolism was detected in the iodine images. CONCLUSION SCT may contribute to the differentiation of histological NSCLC subtypes and improve the identification of LN metastases. VNS differentiates adrenal adenoma from metastasis. In case of pulmonary embolism, iodine imaging can visualise associated pulmonary perfusion defects.
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Carotti M, Salaffi F, Beci G, Giovagnoni A. The application of dual-energy computed tomography in the diagnosis of musculoskeletal disorders: a review of current concepts and applications. Radiol Med 2019; 124:1175-1183. [DOI: 10.1007/s11547-019-01015-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 02/21/2019] [Indexed: 12/27/2022]
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Wang T, Ghavidel BB, Beitler JJ, Tang X, Lei Y, Curran WJ, Liu T, Yang X. Optimal virtual monoenergetic image in "TwinBeam" dual-energy CT for organs-at-risk delineation based on contrast-noise-ratio in head-and-neck radiotherapy. J Appl Clin Med Phys 2019; 20:121-128. [PMID: 30693665 PMCID: PMC6370994 DOI: 10.1002/acm2.12539] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/21/2018] [Accepted: 01/02/2019] [Indexed: 01/04/2023] Open
Abstract
PURPOSE Dual-energy computed tomography (DECT) using TwinBeam CT (TBCT) is a new option for radiation oncology simulators. TBCT scanning provides virtual monoenergetic images which are attractive in treatment planning since lower energies offer better contrast for soft tissues, and higher energies reduce noise. A protocol is needed to achieve optimal performance of this feature. In this study, we investigated the TBCT scan schema with the head-and-neck radiotherapy workflow at our clinic and selected the optimal energy with best contrast-noise-ratio (CNR) in organs-at-risks (OARs) delineation for head-and-neck treatment planning. METHODS AND MATERIALS We synthesized monochromatic images from 40 keV to 190 keV at 5 keV increments from data acquired by TBCT. We collected the Hounsfield unit (HU) numbers of OARs (brainstem, mandible, spinal cord, and parotid glands), the HU numbers of marginal regions outside OARs, and the noise levels for each monochromatic image. We then calculated the CNR for the different OARs at each energy level to generate a serial of spectral curves for each OAR. Based on these spectral curves of CNR, the mono-energy corresponding to the max CNR was identified for each OAR of each patient. RESULTS Computed tomography scans of ten patients by TBCT were used to test the optimal monoenergetic image for the CNR of OAR. Based on the maximized CNR, the optimal energy values were 78.5 ± 5.3 keV for the brainstem, 78.0 ± 4.2 keV for the mandible, 78.5 ± 5.7 keV for the parotid glands, and 78.5 ± 5.3 keV for the spinal cord. Overall, the optimal energy for the maximum CNR of these OARs in head-and-neck cancer patients was 80 keV. CONCLUSION We have proposed a clinically feasible protocol that selects the optimal energy level of the virtual monoenergetic image in TBCT for OAR delineation based on the CNR in head-and-neck OAR. This protocol can be applied in TBCT simulation.
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Affiliation(s)
- Tonghe Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Beth Bradshaw Ghavidel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Jonathan J Beitler
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Xiangyang Tang
- Department of Radiology and Imaging Sciences and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Yang Lei
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Walter J Curran
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
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Martin SS, van Assen M, Griffith LP, De Cecco CN, Varga-Szemes A, Bauer MJ, Wichmann JL, Vogl TJ, Schoepf UJ. Dual-Energy CT Pulmonary Angiography: Quantification of Disease Burden and Impact on Management. CURRENT RADIOLOGY REPORTS 2018. [DOI: 10.1007/s40134-018-0297-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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25
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De Santis D, Eid M, De Cecco CN, Jacobs BE, Albrecht MH, Varga-Szemes A, Tesche C, Caruso D, Laghi A, Schoepf UJ. Dual-Energy Computed Tomography in Cardiothoracic Vascular Imaging. Radiol Clin North Am 2018; 56:521-534. [PMID: 29936945 DOI: 10.1016/j.rcl.2018.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Dual energy computed tomography is becoming increasingly widespread in clinical practice. It can expand on the traditional density-based data achievable with single energy computed tomography by adding novel applications to help reach a more accurate diagnosis. The implementation of this technology in cardiothoracic vascular imaging allows for improved image contrast, metal artifact reduction, generation of virtual unenhanced images, virtual calcium subtraction techniques, cardiac and pulmonary perfusion evaluation, and plaque characterization. The improved diagnostic performance afforded by dual energy computed tomography is not associated with an increased radiation dose. This review provides an overview of dual energy computed tomography cardiothoracic vascular applications.
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Affiliation(s)
- Domenico De Santis
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA; Department of Radiological Sciences, Oncology and Pathology, University of Rome "Sapienza", Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Marwen Eid
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA
| | - Carlo N De Cecco
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA
| | - Brian E Jacobs
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA
| | - Moritz H Albrecht
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA; Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, Frankfurt am Main 60590, Germany
| | - Akos Varga-Szemes
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA
| | - Christian Tesche
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA; Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Lazarettstraße 36, Munich 80636, Germany
| | - Damiano Caruso
- Department of Radiological Sciences, Oncology and Pathology, University of Rome "Sapienza", Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Andrea Laghi
- Department of Radiological Sciences, Oncology and Pathology, University of Rome "Sapienza", Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Uwe Joseph Schoepf
- Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC 29425, USA.
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Cascio V, Hon M, Haramati LB, Gour A, Spiegler P, Bhalla S, Katz DS. Imaging of suspected pulmonary embolism and deep venous thrombosis in obese patients. Br J Radiol 2018; 91:20170956. [PMID: 29762047 DOI: 10.1259/bjr.20170956] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Obesity is a growing problem around the world, and radiology departments frequently encounter difficulties related to large patient size. Diagnosis and management of suspected venous thromboembolism, in particular deep venous thrombosis (DVT) and pulmonary embolism (PE), are challenging even in some lean patients, and can become even more complicated in the setting of obesity. Many obstacles must be overcome to obtain imaging examinations in obese patients with suspected PE and/or DVT, and to ensure that these examinations are of sufficient quality to diagnose or exclude thromboembolic disease, or to establish an alternative diagnosis. Equipment limitations and technical issues both need to be acknowledged and addressed. Table weight limits and scanner sizes that readily accommodate obese and even morbidly obese patients are not in place at many clinical sites. There are also issues with image quality, which can be substantially compromised. We discuss current understanding of the effects of patient size on imaging in general and, more specifically, on the imaging modalities used for the diagnosis and treatment of DVT and PE. Emphasis will be placed on the technical parameters and protocol nuances, including contrast dosing, which are necessary to refine and optimize images for the diagnosis of DVT and PE in obese patients, while remaining cognizant of radiation exposure. More research is necessary to develop consistent high-level evidence regarding protocols to guide radiologists, and to help them effectively utilize emerging technology.
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Affiliation(s)
- Vincent Cascio
- 1 Stony Brook University School of Medicine , Stony Brook, NY , USA.,2 Department of Radiology, NYU Winthrop, Stony Brook University School of Medicine , Mineola, NY , USA
| | - Man Hon
- 3 Interventional Radiology, NYU Winthrop, Stony Brook University School of Medicine , Stony Brook, NY , USA
| | - Linda B Haramati
- 4 Division of Cardiothoracic Imaging, Montefiore Medical Center and the Albert Einstein College of Medicine , Bronx, NY , USA
| | - Animesh Gour
- 5 Division of Pulmonaryand Critical Care Medicine, Department of Internal Medicine, NYU Winthrop , Mineola, NY , USA
| | - Peter Spiegler
- 1 Stony Brook University School of Medicine , Stony Brook, NY , USA
| | - Sanjeev Bhalla
- 6 Mallinckrodt Institute of Radiology, Washington University School of Medicine , St Louis, MO , USA
| | - Douglas S Katz
- 2 Department of Radiology, NYU Winthrop, Stony Brook University School of Medicine , Mineola, NY , USA
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Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the potentially curable causes of pulmonary hypertension and is definitively treated with pulmonary thromboendartectomy. CTEPH can be overlooked, as its symptoms are nonspecific and can be mimicked by a wide range of diseases that can cause pulmonary hypertension. Early diagnosis of CTEPH and prompt evaluation for surgical candidacy are paramount factors in determining future outcomes. Imaging plays a central role in the diagnosis of CTEPH and patient selection for pulmonary thromboendartectomy and balloon pulmonary angioplasty. Currently, various imaging tools are used in concert, with techniques such as computed tomography (CT) and conventional pulmonary angiography providing detailed structural information, tests such as ventilation-perfusion (V/Q) scanning providing functional data, and magnetic resonance imaging providing a combination of morphologic and functional information. Emerging techniques such as dual-energy CT and single photon emission computed tomography-CT V/Q scanning promise to provide both anatomic and functional information in a single test and may change the way we image these patients in the near future. In this review, we discuss the roles of various imaging techniques and discuss their merits, limitations, and relative strengths in depicting the structural and functional changes of CTEPH. We also explore newer imaging techniques and the potential value they may offer.
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Fukuda T, Umezawa Y, Asahina A, Nakagawa H, Furuya K, Fukuda K. Dual energy CT iodine map for delineating inflammation of inflammatory arthritis. Eur Radiol 2017; 27:5034-5040. [PMID: 28674965 DOI: 10.1007/s00330-017-4931-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/10/2017] [Accepted: 06/07/2017] [Indexed: 01/08/2023]
Abstract
Iodine mapping is an image-processing technique used with dual-energy computed tomography (DECT) to improve iodine contrast resolution. CT, because of its high spatial resolution and thin slice reconstruction, is well suited to the evaluation of the peripheral joints. Recent developments in the treatment of inflammatory arthritis that require early diagnosis and precise therapeutic assessment encourage radiological evaluation. To facilitate such assessment, we describe DECT iodine mapping as a novel modality for evaluating rheumatoid arthritis and psoriatic arthritis of the hands and feet. KEY POINTS • Dual-energy CT iodine mapping can delineate inflammation of peripheral inflammatory arthritis. • DECT iodine mapping has high spatial resolution compared with MRI. • DECT iodine mapping has a high iodine contrast resolution. • DECT iodine mapping may reflect therapeutic effects.
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Affiliation(s)
- Takeshi Fukuda
- Department of Radiology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan.
| | - Yoshinori Umezawa
- Department of Dermatology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan
| | - Akihiko Asahina
- Department of Dermatology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan
| | - Hidemi Nakagawa
- Department of Dermatology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan
| | - Kazuhiro Furuya
- Division of Rheumatology Department of Internal Medicine, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan
| | - Kunihiko Fukuda
- Department of Radiology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo, 1058471, Japan
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Sista AK, Kuo WT, Schiebler M, Madoff DC. Stratification, Imaging, and Management of Acute Massive and Submassive Pulmonary Embolism. Radiology 2017. [DOI: 10.1148/radiol.2017151978] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Akhilesh K. Sista
- From the Dept of Radiology, Div of Interventional Radiology, Weill Cornell Medical College, 525 E 68th St, New York, NY 10065 (A.K.S., D.C.M.); Dept of Radiology, Div of Interventional Radiology, Stanford Univ School of Medicine, Stanford, Calif (W.T.K.); and Dept of Radiology, Univ of Wisconsin School of Medicine, Madison, Wis (M.S.)
| | - William T. Kuo
- From the Dept of Radiology, Div of Interventional Radiology, Weill Cornell Medical College, 525 E 68th St, New York, NY 10065 (A.K.S., D.C.M.); Dept of Radiology, Div of Interventional Radiology, Stanford Univ School of Medicine, Stanford, Calif (W.T.K.); and Dept of Radiology, Univ of Wisconsin School of Medicine, Madison, Wis (M.S.)
| | - Mark Schiebler
- From the Dept of Radiology, Div of Interventional Radiology, Weill Cornell Medical College, 525 E 68th St, New York, NY 10065 (A.K.S., D.C.M.); Dept of Radiology, Div of Interventional Radiology, Stanford Univ School of Medicine, Stanford, Calif (W.T.K.); and Dept of Radiology, Univ of Wisconsin School of Medicine, Madison, Wis (M.S.)
| | - David C. Madoff
- From the Dept of Radiology, Div of Interventional Radiology, Weill Cornell Medical College, 525 E 68th St, New York, NY 10065 (A.K.S., D.C.M.); Dept of Radiology, Div of Interventional Radiology, Stanford Univ School of Medicine, Stanford, Calif (W.T.K.); and Dept of Radiology, Univ of Wisconsin School of Medicine, Madison, Wis (M.S.)
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Lee SW, Lee SM, Shin SY, Park TS, Oh SY, Kim N, Hong Y, Lee JS, Oh YM, Lee SD, Seo JB. Improvement in Ventilation-Perfusion Mismatch after Bronchoscopic Lung Volume Reduction: Quantitative Image Analysis. Radiology 2017; 285:250-260. [PMID: 28510483 DOI: 10.1148/radiol.2017162148] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To evaluate whether bronchoscopic lung volume reduction (BLVR) increases ventilation and therefore improves ventilation-perfusion (V/Q) mismatch. Materials and Methods All patients provided written informed consent to be included in this study, which was approved by the Institutional Review Board (2013-0368) of Asan Medical Center. The physiologic changes that occurred after BLVR were measured by using xenon-enhanced ventilation and iodine-enhanced perfusion dual-energy computed tomography (CT). Patients with severe emphysema plus hyperinflation who did not respond to usual treatments were eligible. Pulmonary function tests, the 6-minute walking distance (6MWD) test, quality of life assessment, and dual-energy CT were performed at baseline and 3 months after BLVR. The effect of BLVR was assessed with repeated-measures analysis of variance. Results Twenty-one patients were enrolled in this study (median age, 68 years; mean forced expiratory volume in 1 second [FEV1], 0.75 L ± 0.29). After BLVR, FEV1 (P < .001) and 6MWD (P = .002) improved significantly. Despite the reduction in lung volume (-0.39 L ± 0.44), both ventilation per voxel (P < .001) and total ventilation (P = .01) improved after BLVR. However, neither perfusion per voxel (P = .16) nor total perfusion changed significantly (P = .49). Patients with lung volume reduction of 50% or greater had significantly better improvement in FEV1 (P = .02) and ventilation per voxel (P = .03) than patients with lung volume reduction of less than 50%. V/Q mismatch also improved after BLVR (P = .005), mainly owing to the improvement in ventilation. Conclusion The dual-energy CT analyses showed that BLVR improved ventilation and V/Q mismatch. This increased lung efficiency may be the primary mechanism of improvement after BLVR, despite the reduction in lung volume. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Sei Won Lee
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Sang Min Lee
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - So Youn Shin
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Tai Sun Park
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Sang Young Oh
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Namkug Kim
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Yoonki Hong
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Jae Seung Lee
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Yeon-Mok Oh
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Sang-Do Lee
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
| | - Joon Beom Seo
- From the Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases (S.W.L., T.S.P., J.S.L., Y.M.O., S.D.L.) and Department of Radiology and Research Institute of Radiology (S.M.L., S.Y.S., S.Y.O., N.K., J.B.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea; Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea (S.Y.S.); Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea (T.S.P.); and Department of Internal Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea (Y.H.)
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Takx RAP, Henzler T, Schoepf UJ, Germann T, Schoenberg SO, Shirinova A, Bauer RW, Frellesen C, Zhang LJ, Nance JW, Fink C, Apfaltrer P. Predictive value of perfusion defects on dual energy CTA in the absence of thromboembolic clots. J Cardiovasc Comput Tomogr 2017; 11:183-187. [PMID: 28431860 DOI: 10.1016/j.jcct.2017.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/05/2017] [Accepted: 04/15/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND To determine the predictive value of volumetrically measured lung perfusion defects (PDvol) and right ventricular dysfunction on dual-energy computed tomography angiography (DE-CTA) for predicting all cause mortality in patients suspected of pulmonary embolism (PE) but without evident thromboembolic clot on CTA. METHODS 448 patients underwent DE-CTA on a 64-channel DSCT system between January 2007 and December 2012 for suspected PE, of which 115 were without detectable thromboembolic clot on CTA. Diagnostic performance for identifying patients at risk of dying was evaluated using ROC analysis. All-cause mortality was assessed via the hospital electronic medical records and/or consultation of the patient or the patient's primary care physician via phone call interviews. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve (AUC) were determined for PDvol (volume of perfusion defects/total lung volume), transverse right ventricular to left ventricular diameter ratios (RV/LV) and for the combination of both tests. RESULTS Mortality was 38% within the investigated time period of 6 months. Patients who died had significantly higher PDvol (PDvol 28 ± 13% vs. 19 ± 12%, p < 0.001) and a non-significant difference in transverse RV/LV ratio (1.14 ± 0.37 vs. 1.06 ± 0.22, p = 0.159). The AUC was 0.71 for PDvol, 0.53 for RV/LV ratio, and 0.67 for the combination of PDvol and RV/LV ratio. PDvol remained a significant predictor after correcting for age. CONCLUSIONS In the absence of thromboembolic clots, PDvol at DE-CTA appears to be predictive for all cause mortality.
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Affiliation(s)
- Richard A P Takx
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Thomas Henzler
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States.
| | - Thomas Germann
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefan O Schoenberg
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Aysel Shirinova
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Ralf W Bauer
- Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany; Clinic of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, Switzerland
| | - Claudia Frellesen
- Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, Germany
| | - Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - John W Nance
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Christian Fink
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Radiology, General Hospital Celle, Celle, Germany
| | - Paul Apfaltrer
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States; Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
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White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 3. J Comput Assist Tomogr 2017; 41:1-7. [DOI: 10.1097/rct.0000000000000538] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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State-of-the-Art Pulmonary CT Angiography for Acute Pulmonary Embolism. AJR Am J Roentgenol 2016; 208:495-504. [PMID: 27897042 DOI: 10.2214/ajr.16.17202] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Pulmonary CT angiography (CTA) is the imaging modality of choice in suspected acute pulmonary embolism (PE). Current pulmonary CTA techniques involve ever lower doses of contrast medium and radiation along with advanced postprocessing applications to enhance image quality, diagnostic accuracy, and provide added value in patient management. The objective of this article is to summarize these current developments and discuss the appropriate use of state-of-the-art pulmonary CTA. CONCLUSION Pulmonary CTA is well established as a fast and reliable means of excluding or diagnosing PE. Continued developments in CT system hardware and postprocessing techniques will allow incremental reductions in radiation and contrast material requirements while improving image quality. Advances in risk stratification and prognostication from pulmonary CTA examinations should further refine its clinical value while minimizing the potential harm from overutilization and overdiagnosis.
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Hwang HJ, Hoffman EA, Lee CH, Goo JM, Levin DL, Kauczor HU, Seo JB. The role of dual-energy computed tomography in the assessment of pulmonary function. Eur J Radiol 2016; 86:320-334. [PMID: 27865580 DOI: 10.1016/j.ejrad.2016.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/02/2016] [Accepted: 11/04/2016] [Indexed: 01/05/2023]
Abstract
The assessment of pulmonary function, including ventilation and perfusion status, is important in addition to the evaluation of structural changes of the lung parenchyma in various pulmonary diseases. The dual-energy computed tomography (DECT) technique can provide the pulmonary functional information and high resolution anatomic information simultaneously. The application of DECT for the evaluation of pulmonary function has been investigated in various pulmonary diseases, such as pulmonary embolism, asthma and chronic obstructive lung disease and so on. In this review article, we will present principles and technical aspects of DECT, along with clinical applications for the assessment pulmonary function in various lung diseases.
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Affiliation(s)
- Hye Jeon Hwang
- Department of Radiology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, 22, Gwanpyeong-ro 170beon-gil, Dongan-gu, Anyang-si, Gyeonggi-do 431-796, Republic of Korea
| | - Eric A Hoffman
- Departments of Radiology, Medicine, and Biomedical Engineering, University of Iowa, 200 Hawkins Dr, CC 701 GH, Iowa City, IA 52241, United States
| | - Chang Hyun Lee
- Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Jin Mo Goo
- Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Republic of Korea
| | - David L Levin
- Department of Radiology, Mayo Clinic College of Medicine, 200 First Street, SW, Rochester, MN 55905, United States
| | - Hans-Ulrich Kauczor
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Joon Beom Seo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap 2-dong, Songpa-ku, Seoul, 05505, Republic of Korea.
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Wang T, Zhu L. Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR). Phys Med Biol 2016; 61:6684-6706. [PMID: 27552793 DOI: 10.1088/0031-9155/61/18/6684] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Conventional dual-energy CT (DECT) reconstruction requires two full-size projection datasets with two different energy spectra. In this study, we propose an iterative algorithm to enable a new data acquisition scheme which requires one full scan and a second sparse-view scan for potential reduction in imaging dose and engineering cost of DECT. A bilateral filter is calculated as a similarity matrix from the first full-scan CT image to quantify the similarity between any two pixels, which is assumed unchanged on a second CT image since DECT scans are performed on the same object. The second CT image from reduced projections is reconstructed by an iterative algorithm which updates the image by minimizing the total variation of the difference between the image and its filtered image by the similarity matrix under data fidelity constraint. As the redundant structural information of the two CT images is contained in the similarity matrix for CT reconstruction, we refer to the algorithm as structure preserving iterative reconstruction (SPIR). The proposed method is evaluated on both digital and physical phantoms, and is compared with the filtered-backprojection (FBP) method, the conventional total-variation-regularization-based algorithm (TVR) and prior-image-constrained-compressed-sensing (PICCS). SPIR with a second 10-view scan reduces the image noise STD by a factor of one order of magnitude with same spatial resolution as full-view FBP image. SPIR substantially improves over TVR on the reconstruction accuracy of a 10-view scan by decreasing the reconstruction error from 6.18% to 1.33%, and outperforms TVR at 50 and 20-view scans on spatial resolution with a higher frequency at the modulation transfer function value of 10% by an average factor of 4. Compared with the 20-view scan PICCS result, the SPIR image has 7 times lower noise STD with similar spatial resolution. The electron density map obtained from the SPIR-based DECT images with a second 10-view scan has an average error of less than 1%.
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Affiliation(s)
- Tonghe Wang
- Nuclear & Radiological Engineering and Medical Physics Programs, The George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Single Phase Dual-energy CT Angiography: One-stop-shop Tool for Evaluating Aneurysmal Subarachnoid Hemorrhage. Sci Rep 2016; 6:26704. [PMID: 27222163 PMCID: PMC4879615 DOI: 10.1038/srep26704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 05/06/2016] [Indexed: 01/29/2023] Open
Abstract
Aneurysmal subarachnoid hemorrhages have extremely high case fatality in clinic. Early and rapid identifications of ruptured intracranial aneurysms seem to be especially important. Here we evaluate clinical value of single phase contrast-enhanced dual-energy CT angiograph (DE-CTA) as a one-stop-shop tool in detecting aneurysmal subarachnoid hemorrhage. One hundred and five patients who underwent true non-enhanced CT (TNCT), contrast-enhanced DE-CTA and digital subtraction angiography (DSA) were included. Image quality and detectability of intracranial hemorrhage were evaluated and compared between virtual non-enhanced CT (VNCT) images reconstructed from DE-CTA and TNCT. There was no statistical difference in image quality (P > 0.05) between VNCT and TNCT. The agreement of VNCT and TNCT in detecting intracranial hemorrhage reached 98.1% on a per-patient basis. With DSA as reference standard, sensitivity and specificity on a per-patient were 98.3% and 97.9% for DE-CTA in intracranial aneurysm detection. Effective dose of DE-CTA was reduced by 75.0% compared to conventional digital subtraction CTA. Thus, single phase contrast-enhanced DE-CTA is optimal reliable one-stop-shop tool for detecting intracranial hemorrhage with VNCT and intracranial aneurysms with DE-CTA with substantial radiation dose reduction compared with conventional digital subtraction CTA.
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Hong SR, Chang S, Im DJ, Suh YJ, Hong YJ, Hur J, Kim YJ, Choi BW, Lee HJ. Feasibility of Single Scan for Simultaneous Evaluation of Regional Krypton and Iodine Concentrations with Dual-Energy CT: An Experimental Study. Radiology 2016; 281:597-605. [PMID: 27203543 DOI: 10.1148/radiol.16152429] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To evaluate the feasibility of a simultaneous single scan of regional krypton and iodine concentrations by using dual-energy computed tomography (CT). Materials and Methods The study was approved by the institutional animal experimental committee. An airway obstruction model was first made in 10 beagle dogs, and a pulmonary arterial occlusion was induced in each animal after 1 week. For each model, three sessions of dual-energy CT (80% krypton ventilation [krypton CT], 80% krypton ventilation with iodine enhancement [mixed-contrast agent CT], and iodine enhancement [iodine CT]) were performed. Krypton maps were made from krypton and mixed-contrast agent CT, and iodine maps were made from iodine and mixed-contrast agent CT. Observers measured overlay Hounsfield units of the diseased and contralateral segments on each map. Values were compared by using the Wilcoxon signed-rank test. Results In krypton maps of airway obstruction, overlay Hounsfield units of diseased segments were significantly decreased compared with those of contralateral segments in both krypton and mixed-contrast agent CT (P = .005 for both). However, the values of mixed-contrast agent CT were significantly higher than those of krypton CT for both segments (P = .005 and .007, respectively). In iodine maps of pulmonary arterial occlusion, values were significantly lower in diseased segments than in contralateral segments for both iodine and mixed-contrast agent CT (P = .005 for both), without significant difference between iodine and mixed-contrast agent CT for both segments (P = .126 and .307, respectively). Conclusion Although some limitations may exist, it might be feasible to analyze regional krypton and iodine concentrations simultaneously by using dual-energy CT. © RSNA, 2016.
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Affiliation(s)
- Sae Rom Hong
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Suyon Chang
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Dong Jin Im
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Young Joo Suh
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Yoo Jin Hong
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Jin Hur
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Young Jin Kim
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Byoung Wook Choi
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Hye-Jeong Lee
- From the Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
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Mao X, Wang S, Jiang X, Zhang L, Xu W. Diagnostic Value of Dual-Source Computerized Tomography Combined with Perfusion Imaging for Peripheral Pulmonary Embolism. IRANIAN JOURNAL OF RADIOLOGY : A QUARTERLY JOURNAL PUBLISHED BY THE IRANIAN RADIOLOGICAL SOCIETY 2016; 13:e29402. [PMID: 27703656 PMCID: PMC5039736 DOI: 10.5812/iranjradiol.29402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 02/06/2016] [Accepted: 02/14/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulmonary embolism has become the third most common cardiovascular disease, which can seriously harm human health. OBJECTIVES To investigate the diagnostic value of dual-source computerized tomography (CT) and perfusion imaging for peripheral pulmonary embolism. PATIENTS AND METHODS Thirty-two patients with suspected pulmonary embolism underwent dual-source CT exams. To compare the ability of pulmonary embolism detection software (PED) with CT pulmonary angiography (CTPA) in determining the presence, numbers, and locations of pulmonary emboli, the subsequent images were reviewed by two radiologists using both imaging modalities. Also, the diagnostic consistency between PED and CTPA images and dual-energy pulmonary perfusion imaging (DEPI) for segmental pulmonary embolism was compared. RESULTS CTPA images revealed 50 (7.81%) segmental and 56 (4.38%) sub-segmental pulmonary embolisms, while the PED images showed 68 (10.63%) segmental and 94 (7.34%) sub-segmental pulmonary embolisms. Thus, the detection rate on PED images for peripheral pulmonary embolism was significantly higher than that of the CTPA images (P < 0.05). There was good consistency for diagnosing segmental pulmonary embolism between PED and CTPA and DEPI (kappa = 0.85). The sensitivity and specificity of DEPI images for the diagnosis of pulmonary embolism were 91.7% and 97.5%, respectively. CONCLUSION PED software of dual-source CT combined with perfusion imaging can significantly improve the detection rate of peripheral pulmonary embolism.
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Affiliation(s)
- Xijin Mao
- Department of Radiology, Affiliated Hospital of Qingdao University, Qingdao, China
- Department of Radiology, Affiliated Hospital of Binzhou Medical College, Binzhou, China
| | - Shanshan Wang
- Department of Radiology, Affiliated Hospital of Binzhou Medical College, Binzhou, China
| | - Xingyue Jiang
- Department of Radiology, Affiliated Hospital of Binzhou Medical College, Binzhou, China
| | - Lin Zhang
- Department of Radiology, Affiliated Hospital of Binzhou Medical College, Binzhou, China
| | - Wenjian Xu
- Department of Radiology, Affiliated Hospital of Qingdao University, Qingdao, China
- Corresponding author: Wenjian Xu, Department of Radiology, Affiliated Hospital of Qingdao University, Qingdao, China. Tel: +86-13963952822, Fax: +86-53282824980, E-mail:
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Baldi S, Hartley R, Brightling C, Gupta S. Asthma. IMAGING 2016. [DOI: 10.1183/2312508x.10002815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Abstract
OBJECTIVES The objective of this study was to assess the feasibility and safety of krypton ventilation imaging with intraindividual comparison to xenon ventilation computed tomography (CT). MATERIALS AND METHODS In a first step, attenuation of different concentrations of xenon and krypton was analyzed in a phantom setting. Thereafter, 7 male New Zealand white rabbits (4.4-6.0 kg) were included in an animal study. After orotracheal intubation, an unenhanced CT scan was obtained in end-inspiratory breath-hold. Thereafter, xenon- (30%) and krypton-enhanced (70%) ventilation CT was performed in random order. After a 2-minute wash-in of gas A, CT imaging was performed. After a 45-minute wash-out period and another 2-minute wash-in of gas B, another CT scan was performed using the same scan protocol. Heart rate and oxygen saturation were measured. Unenhanced and krypton or xenon data were registered and subtracted using a nonrigid image registration tool. Enhancement was quantified and statistically analyzed. RESULTS One animal had to be excluded from data analysis owing to problems during intubation. The CT scans in the remaining 6 animals were completed without complications. There were no relevant differences in oxygen saturation or heart rate between the scans. Xenon resulted in a mean increase of enhancement of 35.3 ± 5.5 HU, whereas krypton achieved a mean increase of 21.9 ± 1.8 HU in enhancement (P = 0.0055). CONCLUSIONS The use of krypton for lung ventilation imaging appears to be feasible and safe. Despite the use of a markedly higher concentration of krypton, enhancement is significantly worse when compared with xenon CT ventilation imaging, but sufficiently high for CT ventilation imaging studies.
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Where do we stand? Functional imaging in acute and chronic pulmonary embolism with state-of-the-art CT. Eur J Radiol 2015; 84:2432-7. [DOI: 10.1016/j.ejrad.2015.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 09/17/2015] [Indexed: 01/26/2023]
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Sudarski S, Hagelstein C, Weis M, Schoenberg SO, Apfaltrer P. Dual-energy snap-shot perfusion CT in suspect pulmonary nodules and masses and for lung cancer staging. Eur J Radiol 2015; 84:2393-400. [DOI: 10.1016/j.ejrad.2015.09.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 09/27/2015] [Indexed: 10/23/2022]
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Chronic thromboembolic pulmonary hypertension: Comparison of dual-energy computed tomography and single photon emission computed tomography in canines. Eur J Radiol 2015; 85:498-506. [PMID: 26781157 DOI: 10.1016/j.ejrad.2015.11.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/24/2015] [Accepted: 11/26/2015] [Indexed: 11/23/2022]
Abstract
PURPOSE To compare diagnostic accuracy between dual-energy CT lung perfused blood volume (Lung PBV) imaging and single photon emission computed tomography (SPECT) in detecting chronic thromboembolic pulmonary hypertension (CTEPH) with histopathological results as reference standard in a canine model. MATERIALS AND METHODS Eighteen CTEPH canines were included into this experimental study. All procedures including paracentesis, embolization, scanning, pressure measurement and feeding medicine were repeated each two weeks, until systolic/diastolic pressure in canines was ≥ 30/15 mm Hg or mean pulmonary artery pressure ≥ 20 mm Hg, and then sacrificed for histopathology examination. Two radiologists (readers 1 and 2) and two nuclear radiologists (readers 3 and 4) analyzed images of conventional CT pulmonary angiography in dual-energy CT mode, Lung PBV imaging and SPECT, respectively. The presence, numbers, and locations of pulmonary emboli (PE) were recorded on a per-lobe basis. Pathological examination was served as reference standard. Sensitivity, specificity and accuracy of Lung PBV and SPECT were calculated. Kappa statistics were used to quantify inter-reader agreement. RESULTS With histopathological results as reference standard, the sensitivities of 72.2%, 78.8%, 81.2%, specificities of 75.9%, 87.5%, 84.8%, accuracies of 73.8%, 83.1%, 83.1%, for readers 1, 2 and both with Lung PBV, respectively. Readers 3, 4 and both had sensitivities of 14.3%, 25.7%, 33.3%, specificities of 90.0%, 86.7%, 93.3%, accuracies of 49.2%, 53.8%, 60.0% with SPECT for detecting CTEPH. Inter-reader agreements were good for dual-energy CT (kappa=0.662) and SPECT (k=0.706) for detecting CTEPH. CONCLUSION Dual-energy CT had a higher accuracy to detect CTEPH than SPECT in this canine model study.
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McCollough CH, Leng S, Yu L, Fletcher JG. Dual- and Multi-Energy CT: Principles, Technical Approaches, and Clinical Applications. Radiology 2015; 276:637-53. [PMID: 26302388 DOI: 10.1148/radiol.2015142631] [Citation(s) in RCA: 969] [Impact Index Per Article: 107.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In x-ray computed tomography (CT), materials having different elemental compositions can be represented by identical pixel values on a CT image (ie, CT numbers), depending on the mass density of the material. Thus, the differentiation and classification of different tissue types and contrast agents can be extremely challenging. In dual-energy CT, an additional attenuation measurement is obtained with a second x-ray spectrum (ie, a second "energy"), allowing the differentiation of multiple materials. Alternatively, this allows quantification of the mass density of two or three materials in a mixture with known elemental composition. Recent advances in the use of energy-resolving, photon-counting detectors for CT imaging suggest the ability to acquire data in multiple energy bins, which is expected to further improve the signal-to-noise ratio for material-specific imaging. In this review, the underlying motivation and physical principles of dual- or multi-energy CT are reviewed and each of the current technical approaches is described. In addition, current and evolving clinical applications are introduced.
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Affiliation(s)
- Cynthia H McCollough
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905
| | - Shuai Leng
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905
| | - Lifeng Yu
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905
| | - Joel G Fletcher
- From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905
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Cai XR, Feng YZ, Qiu L, Xian ZH, Yang WC, Mo XK, Wang XB. Iodine Distribution Map in Dual-Energy Computed Tomography Pulmonary Artery Imaging with Rapid kVp Switching for the Diagnostic Analysis and Quantitative Evaluation of Acute Pulmonary Embolism. Acad Radiol 2015; 22:743-51. [PMID: 25772582 DOI: 10.1016/j.acra.2015.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 01/28/2015] [Accepted: 01/30/2015] [Indexed: 01/01/2023]
Abstract
RATIONALE AND OBJECTIVES To assess the diagnostic value of dual-energy (DE) computed tomography pulmonary angiography (CTPA) for acute pulmonary embolism (PE) using a helical DE scan mode with rapid kVp switching. MATERIALS AND METHODS Seventy-six patients with suspected acute PE underwent DE CTPA. Two readers independently assessed and measured the iodine maps. CTPA images were assessed for the presence, location, and degree of PE as the standard of reference. Iodine maps were used to identify the perfusion defect (PD), and the diagnostic accuracy of iodine maps was calculated. The iodine concentrations of PDs and normal lung parenchyma were also measured and compared. RESULTS A per-patient analysis showed the 84.6% sensitivity and 96.0% specificity of iodine map for PE, and on per-segment analysis, the sensitivity and specificity for PE were 82.9% and 99.6%, respectively. Intraobserver and interobserver variability correlations were excellent, with k values from 0.806 to 1.000. Quantitative analysis showed there was a significant difference for iodine concentration between circumscribed/patchy PDs or wedge-shaped PDs consistent with PE and normal lung parenchyma (P < .05). The intraobserver reliability of reader 1 was from 0.928 to 0.997, and reader 2 was from 0.912 to 0.995. And, the interobserver reliability between two readers was from 0.967 to 0.999. CONCLUSIONS CTPA based on DE scanning with rapid kVp switching can provide both morphologic analysis and quantitative evaluation of PD related to acute PE in addition to standard CTPA data. Quantification of iodine concentration may be helpful for identifying the presence or absence of PE.
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Affiliation(s)
- Xiang-Ran Cai
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - You-Zhen Feng
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - Lin Qiu
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - Zhao-Hui Xian
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - Wen-Cai Yang
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - Xu-Kai Mo
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China
| | - Xiao-Bai Wang
- Medical Imaging Center, Department of Radiology, The First Affiliated Hospital, Jinan University, No. 613 West Huangpu Ave, Tianhe District, Guangzhou 510630, China.
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Zhang LJ, Lu GM, Meinel FG, McQuiston AD, Ravenel JG, Schoepf UJ. Computed tomography of acute pulmonary embolism: state-of-the-art. Eur Radiol 2015; 25:2547-57. [DOI: 10.1007/s00330-015-3679-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/17/2015] [Indexed: 12/13/2022]
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Dong X, Niu T, Zhu L. Combined iterative reconstruction and image-domain decomposition for dual energy CT using total-variation regularization. Med Phys 2014; 41:051909. [PMID: 24784388 DOI: 10.1118/1.4870375] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
PURPOSE Dual-energy CT (DECT) is being increasingly used for its capability of material decomposition and energy-selective imaging. A generic problem of DECT, however, is that the decomposition process is unstable in the sense that the relative magnitude of decomposed signals is reduced due to signal cancellation while the image noise is accumulating from the two CT images of independent scans. Direct image decomposition, therefore, leads to severe degradation of signal-to-noise ratio on the resultant images. Existing noise suppression techniques are typically implemented in DECT with the procedures of reconstruction and decomposition performed independently, which do not explore the statistical properties of decomposed images during the reconstruction for noise reduction. In this work, the authors propose an iterative approach that combines the reconstruction and the signal decomposition procedures to minimize the DECT image noise without noticeable loss of resolution. METHODS The proposed algorithm is formulated as an optimization problem, which balances the data fidelity and total variation of decomposed images in one framework, and the decomposition step is carried out iteratively together with reconstruction. The noise in the CT images from the proposed algorithm becomes well correlated even though the noise of the raw projections is independent on the two CT scans. Due to this feature, the proposed algorithm avoids noise accumulation during the decomposition process. The authors evaluate the method performance on noise suppression and spatial resolution using phantom studies and compare the algorithm with conventional denoising approaches as well as combined iterative reconstruction methods with different forms of regularization. RESULTS On the Catphan©600 phantom, the proposed method outperforms the existing denoising methods on preserving spatial resolution at the same level of noise suppression, i.e., a reduction of noise standard deviation by one order of magnitude. This improvement is mainly attributed to the high noise correlation in the CT images reconstructed by the proposed algorithm. Iterative reconstruction using different regularization, including quadratic orq-generalized Gaussian Markov random field regularization, achieves similar noise suppression from high noise correlation. However, the proposed TV regularization obtains a better edge preserving performance. Studies of electron density measurement also show that our method reduces the average estimation error from 9.5% to 7.1%. On the anthropomorphic head phantom, the proposed method suppresses the noise standard deviation of the decomposed images by a factor of ∼14 without blurring the fine structures in the sinus area. CONCLUSIONS The authors propose a practical method for DECT imaging reconstruction, which combines the image reconstruction and material decomposition into one optimization framework. Compared to the existing approaches, our method achieves a superior performance on DECT imaging with respect to decomposition accuracy, noise reduction, and spatial resolution.
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Affiliation(s)
- Xue Dong
- Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Tianye Niu
- Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Lei Zhu
- Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
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