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Sample records for cavitating lung nodule

  1. Pulmonary cavitary mass containing a mural nodule: differential diagnosis between intracavitary aspergilloma and cavitating lung cancer on contrast-enhanced computed tomography

    International Nuclear Information System (INIS)

    Park, Y.; Kim, T.S.; Yi, C.A.; Cho, E.Y.; Kim, H.; Choi, Y.S.

    2007-01-01

    Aim: The objective of this study was to identify whether there were any significant differences in the computed tomography (CT) findings of an intracavitary aspergilloma and a cavitating lung cancer containing a mural nodule. Materials and methods: The CT and histopathological findings of 12 patients (male:female ratio 3:9; aged 51-76 years) with cavitating lung cancer containing a mural nodule and 26 patients (male:female ratio 14:12; aged 29-72 years) with intracavitary aspergilloma were retrospectively reviewed. Results: The mural nodules within cavitating lung cancer were more enhanced (p < 0.001) and showed a nondependent location more frequently (p = 0.012) than those of intracavitary aspergillomas. The cavitary walls were thicker in cavitating lung cancer (mean 5.8 mm thick) than those in intracavitary aspergillomas (mean 2.6 mm thick; p = 0.035). Adjacent bronchiectasis and volume decrease of the involved lobe were observed more frequently in intracavitary aspergillomas than in cavitating lung cancers (p < 0.001 and p = 0.008, respectively). Conclusion: Whether a mural nodule within a cavitary lesion is contrast-enhanced or not is one of the most important features in making a differential diagnosis between an intracavitary aspergilloma and a cavitating lung cancer. Assessment of dependent location of a mural nodule within the cavity and wall thickness of the cavity itself can also be helpful for differentiation

  2. Pulmonary cavitary mass containing a mural nodule: differential diagnosis between intracavitary aspergilloma and cavitating lung cancer on contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, T.S. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)]. E-mail: tskim.kim@samsung.com; Yi, C.A. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Cho, E.Y. [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Kim, H. [Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of); Choi, Y.S. [Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)

    2007-03-15

    Aim: The objective of this study was to identify whether there were any significant differences in the computed tomography (CT) findings of an intracavitary aspergilloma and a cavitating lung cancer containing a mural nodule. Materials and methods: The CT and histopathological findings of 12 patients (male:female ratio 3:9; aged 51-76 years) with cavitating lung cancer containing a mural nodule and 26 patients (male:female ratio 14:12; aged 29-72 years) with intracavitary aspergilloma were retrospectively reviewed. Results: The mural nodules within cavitating lung cancer were more enhanced (p < 0.001) and showed a nondependent location more frequently (p = 0.012) than those of intracavitary aspergillomas. The cavitary walls were thicker in cavitating lung cancer (mean 5.8 mm thick) than those in intracavitary aspergillomas (mean 2.6 mm thick; p = 0.035). Adjacent bronchiectasis and volume decrease of the involved lobe were observed more frequently in intracavitary aspergillomas than in cavitating lung cancers (p < 0.001 and p = 0.008, respectively). Conclusion: Whether a mural nodule within a cavitary lesion is contrast-enhanced or not is one of the most important features in making a differential diagnosis between an intracavitary aspergilloma and a cavitating lung cancer. Assessment of dependent location of a mural nodule within the cavity and wall thickness of the cavity itself can also be helpful for differentiation.

  3. Can Lung Nodules Be Cancerous?

    Science.gov (United States)

    ... lung nodules be cancerous? Answers from Eric J. Olson, M.D. Yes, lung nodules can be cancerous, ... to determine if it's cancerous. With Eric J. Olson, M.D. AskMayoExpert. Pulmonary nodules. Rochester, Minn.: Mayo ...

  4. Characteristic CT Findings After Percutaneous Cryoablation Treatment of Malignant Lung Nodules.

    Science.gov (United States)

    Chaudhry, Ammar; Grechushkin, Vadim; Hoshmand, Mahsa; Kim, Choo Won; Pena, Andres; Huston, Brett; Chaya, Yair; Bilfinger, Thomas; Moore, William

    2015-10-01

    Assess computed tomography (CT) imaging characteristics after percutaneous cryotherapy for lung cancer.A retrospective IRB-approved analysis of 40 patients who underwent nonsurgical treatment for primary stage 1 lung cancer performed from January 2007 to March 2011 was included in this study. All procedures were performed using general anesthesia and CT guidance. Follow-up imaging with CT of the chest was obtained at 1 month, 3 months, 6 months, and 12 months postprocedure to evaluate the ablated lung nodule. Nodule surface area, density (in Hounsfield units), and presence or absence of cavitations were recorded. In addition, the degree of nodule enhancement was also recorded. Patients who were unable to obtain the aforementioned follow-up were excluded from the study.Thirty-six patients underwent percutaneous cryoablation with men to women ratio of 75% with mean age for men 74.6 and mean age for women 74.3 years of age. The average nodule surface area preablation and postcryoablation at 1-, 3-, 6-, and 12-month follow-ups were 2.99, 7.86, 3.89, 3.18 and 3.07[REPLACEMENT CHARACTER]cm, respectively. The average precontrast nodule density before cryoablation was 8.9 and average precontrast nodule density postprocedure at 1, 3, 6, and 12 months follow-ups were 8.5, -5.9, -9.4, and -3.8 HU, respectively. There is increased attenuation of lung nodules over time with an average postcontrast enhancement of 11.4, 18.5, 16.1, and 25.7 HU at the aforementioned time intervals. Cavitations occurred in the cryoablation zone in 53% (19/36) of patients. 80.6% (29/36) of the cavitations in the cryoablation zone resolved within 12 months. Four patients (11%) had recurrence of tumor at the site of cryoablation and none of the patients had satellite or distant metastasis.Our study shows that patients who underwent cryotherapy for lung nodules treatment had characteristic changes on follow-up CT including. The surface area of the nodule increases at the 1-month follow-up with

  5. Lung Nodule Detection via Deep Reinforcement Learning

    Directory of Open Access Journals (Sweden)

    Issa Ali

    2018-04-01

    Full Text Available Lung cancer is the most common cause of cancer-related death globally. As a preventive measure, the United States Preventive Services Task Force (USPSTF recommends annual screening of high risk individuals with low-dose computed tomography (CT. The resulting volume of CT scans from millions of people will pose a significant challenge for radiologists to interpret. To fill this gap, computer-aided detection (CAD algorithms may prove to be the most promising solution. A crucial first step in the analysis of lung cancer screening results using CAD is the detection of pulmonary nodules, which may represent early-stage lung cancer. The objective of this work is to develop and validate a reinforcement learning model based on deep artificial neural networks for early detection of lung nodules in thoracic CT images. Inspired by the AlphaGo system, our deep learning algorithm takes a raw CT image as input and views it as a collection of states, and output a classification of whether a nodule is present or not. The dataset used to train our model is the LIDC/IDRI database hosted by the lung nodule analysis (LUNA challenge. In total, there are 888 CT scans with annotations based on agreement from at least three out of four radiologists. As a result, there are 590 individuals having one or more nodules, and 298 having none. Our training results yielded an overall accuracy of 99.1% [sensitivity 99.2%, specificity 99.1%, positive predictive value (PPV 99.1%, negative predictive value (NPV 99.2%]. In our test, the results yielded an overall accuracy of 64.4% (sensitivity 58.9%, specificity 55.3%, PPV 54.2%, and NPV 60.0%. These early results show promise in solving the major issue of false positives in CT screening of lung nodules, and may help to save unnecessary follow-up tests and expenditures.

  6. Automated lung nodule classification following automated nodule detection on CT: A serial approach

    International Nuclear Information System (INIS)

    Armato, Samuel G. III; Altman, Michael B.; Wilkie, Joel; Sone, Shusuke; Li, Feng; Doi, Kunio; Roy, Arunabha S.

    2003-01-01

    We have evaluated the performance of an automated classifier applied to the task of differentiating malignant and benign lung nodules in low-dose helical computed tomography (CT) scans acquired as part of a lung cancer screening program. The nodules classified in this manner were initially identified by our automated lung nodule detection method, so that the output of automated lung nodule detection was used as input to automated lung nodule classification. This study begins to narrow the distinction between the 'detection task' and the 'classification task'. Automated lung nodule detection is based on two- and three-dimensional analyses of the CT image data. Gray-level-thresholding techniques are used to identify initial lung nodule candidates, for which morphological and gray-level features are computed. A rule-based approach is applied to reduce the number of nodule candidates that correspond to non-nodules, and the features of remaining candidates are merged through linear discriminant analysis to obtain final detection results. Automated lung nodule classification merges the features of the lung nodule candidates identified by the detection algorithm that correspond to actual nodules through another linear discriminant classifier to distinguish between malignant and benign nodules. The automated classification method was applied to the computerized detection results obtained from a database of 393 low-dose thoracic CT scans containing 470 confirmed lung nodules (69 malignant and 401 benign nodules). Receiver operating characteristic (ROC) analysis was used to evaluate the ability of the classifier to differentiate between nodule candidates that correspond to malignant nodules and nodule candidates that correspond to benign lesions. The area under the ROC curve for this classification task attained a value of 0.79 during a leave-one-out evaluation

  7. Use of Volumetry for Lung Nodule Management: Theory and Practice

    NARCIS (Netherlands)

    Devaraj, A.; Ginneken, B. van; Nair, A.; Baldwin, D.

    2017-01-01

    A consistent feature of many lung nodule management guidelines is the recommendation to evaluate nodule size by using diameter measurements and electronic calipers. Traditionally, the use of nodule volumetry applications has primarily been reserved for certain lung cancer screening trials rather

  8. Lung nodules after whole lung radiation

    International Nuclear Information System (INIS)

    Cohen, M.D.; Mirkin, D.L.; Provisor, A.; Hornback, N.B.; Smith, J.A.; Slabaugh, R.D.

    1983-01-01

    It is essential to recognize radiation pneumonitis after whole lung irradiation, or nodular changes in response to chemotherapy, so that such conditions are not mistaken for tumor metastases, causing grave error in patient management and the possibility of further lung damage

  9. Automatic Solitary Lung Nodule Detection in Computed Tomography Images Slices

    Science.gov (United States)

    Sentana, I. W. B.; Jawas, N.; Asri, S. A.

    2018-01-01

    Lung nodule is an early indicator of some lung diseases, including lung cancer. In Computed Tomography (CT) based image, nodule is known as a shape that appears brighter than lung surrounding. This research aim to develop an application that automatically detect lung nodule in CT images. There are some steps in algorithm such as image acquisition and conversion, image binarization, lung segmentation, blob detection, and classification. Data acquisition is a step to taking image slice by slice from the original *.dicom format and then each image slices is converted into *.tif image format. Binarization that tailoring Otsu algorithm, than separated the background and foreground part of each image slices. After removing the background part, the next step is to segment part of the lung only so the nodule can localized easier. Once again Otsu algorithm is use to detect nodule blob in localized lung area. The final step is tailoring Support Vector Machine (SVM) to classify the nodule. The application has succeed detecting near round nodule with a certain threshold of size. Those detecting result shows drawback in part of thresholding size and shape of nodule that need to enhance in the next part of the research. The algorithm also cannot detect nodule that attached to wall and Lung Chanel, since it depend the searching only on colour differences.

  10. Use of Volumetry for Lung Nodule Management: Theory and Practice.

    Science.gov (United States)

    Devaraj, Anand; van Ginneken, Bram; Nair, Arjun; Baldwin, David

    2017-09-01

    A consistent feature of many lung nodule management guidelines is the recommendation to evaluate nodule size by using diameter measurements and electronic calipers. Traditionally, the use of nodule volumetry applications has primarily been reserved for certain lung cancer screening trials rather than clinical practice. However, even before the first nodule management guidelines were published more than a decade ago, research has been ongoing into the use of nodule volumetry as a means of measuring nodule size, and this research has accelerated in recent years. This article aims to provide radiologists with an up-to-date review of the most recent literature on volumetry and volume doubling times in lung nodule management, outlining their benefits and drawbacks. A brief technical review of typical volumetry applications is also provided. © RSNA, 2017.

  11. An unusual presentation of multiple cavitated lung metastases from colon carcinoma

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    Iannace Alessandro

    2011-05-01

    Full Text Available Abstract Background Consolidation with or without ground-glass opacity is the typical radiologic finding of lung metastases of adenocarcinoma from the gastrointestinal tract. Lung excavated metastases from gastrointestinal carcinoma are very rare. Case presentation The authors describe an unusual presentation of multiple cavitated lung metastases from colon adenocarcinoma and discuss the outcome of a patient. The absence both of symptoms and other disease localizations, the investigations related to different diagnostic hypotheses and the empirical treatments caused a delay in correct diagnosis. Only a transparietal biopsy revealed the neoplastic origin of nodules. Conclusions This report demonstrates that although lung excavated metastases are described in literature, initial failure to reach a diagnosis is common. We would like to alert clinicians and radiologists to the possibility of unusual atypical features of pulmonary metastases from colon adenocarcinoma.

  12. Improved pulmonary nodule classification utilizing quantitative lung parenchyma features.

    Science.gov (United States)

    Dilger, Samantha K N; Uthoff, Johanna; Judisch, Alexandra; Hammond, Emily; Mott, Sarah L; Smith, Brian J; Newell, John D; Hoffman, Eric A; Sieren, Jessica C

    2015-10-01

    Current computer-aided diagnosis (CAD) models for determining pulmonary nodule malignancy characterize nodule shape, density, and border in computed tomography (CT) data. Analyzing the lung parenchyma surrounding the nodule has been minimally explored. We hypothesize that improved nodule classification is achievable by including features quantified from the surrounding lung tissue. To explore this hypothesis, we have developed expanded quantitative CT feature extraction techniques, including volumetric Laws texture energy measures for the parenchyma and nodule, border descriptors using ray-casting and rubber-band straightening, histogram features characterizing densities, and global lung measurements. Using stepwise forward selection and leave-one-case-out cross-validation, a neural network was used for classification. When applied to 50 nodules (22 malignant and 28 benign) from high-resolution CT scans, 52 features (8 nodule, 39 parenchymal, and 5 global) were statistically significant. Nodule-only features yielded an area under the ROC curve of 0.918 (including nodule size) and 0.872 (excluding nodule size). Performance was improved through inclusion of parenchymal (0.938) and global features (0.932). These results show a trend toward increased performance when the parenchyma is included, coupled with the large number of significant parenchymal features that support our hypothesis: the pulmonary parenchyma is influenced differentially by malignant versus benign nodules, assisting CAD-based nodule characterizations.

  13. Fusobacterium necrophorum presenting as isolated lung nodules

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    Rajiv Sonti

    2015-01-01

    Full Text Available Fusobacterium necrophorum causes Lemierre's syndrome - a dramatic and distinct condition beginning with pharyngitis before proceeding to internal jugular vein septic thrombophlebitis and respiratory tract infection in otherwise healthy individuals. It is rare, but by far the most common pathway to parenchymal lung disease with this organism. Here we describe we a 34 year old healthy lady who was nontoxic without any antecedent illness who presented with lung nodules due to fusobacterium necrophorum as the sole manifestation of disease. Leading diagnostic consideration prior to culture data was pulmonary vasculitis. Identifying her disease process was a somewhat chance occurrence, and it began to resolve prior to antibiotic therapy. Though it would be difficult to recommend keen awareness of this organism given its rarity, it is important to consider that its scope may be broader than traditionally considered.

  14. Vasculature surrounding a nodule: A novel lung cancer biomarker.

    Science.gov (United States)

    Wang, Xiaohua; Leader, Joseph K; Wang, Renwei; Wilson, David; Herman, James; Yuan, Jian-Min; Pu, Jiantao

    2017-12-01

    To investigate whether the vessels surrounding a nodule depicted on non-contrast, low-dose computed tomography (LDCT) can discriminate benign and malignant screen detected nodules. We collected a dataset consisting of LDCT scans acquired on 100 subjects from the Pittsburgh Lung Screening study (PLuSS). Fifty subjects were diagnosed with lung cancer and 50 subjects had suspicious nodules later proven benign. For the lung cancer cases, the location of the malignant nodule in the LDCT scans was known; while for the benign cases, the largest nodule in the LDCT scan was used in the analysis. A computer algorithm was developed to identify surrounding vessels and quantify the number and volume of vessels that were connected or near the nodule. A nonparametric receiver operating characteristic (ROC) analysis was performed based on a single nodule per subject to assess the discriminability of the surrounding vessels to provide a lung cancer diagnosis. Odds ratio (OR) were computed to determine the probability of a nodule being lung cancer based on the vessel features. The areas under the ROC curves (AUCs) for vessel count and vessel volume were 0.722 (95% CI=0.616-0.811, plung cancer group 9.7 (±9.6) compared to the non-lung cancer group 4.0 (±4.3) CONCLUSION: Our preliminary results showed that malignant nodules are often surrounded by more vessels compared to benign nodules, suggesting that the surrounding vessel characteristics could serve as lung cancer biomarker for indeterminate nodules detected during LDCT lung cancer screening using only the information collected during the initial visit. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Cavitation

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Cavitation in fluid machines or flow passages can cause loss of performance or material damage due to erosion. This conference reports the results of world-wide research into all aspects of the study of cavitation. Contents include: Cavitation effects in machinery such as pumps, water turbines, propellers and positive displacement machinery; Cavitation in structures, flow passages, valves, flow meters and bearings; Cavitation erosion, noise and instability effects; Cavitation inception; Developed flows; Supercavitating flows and machines; Fundamentals; Bubble dynamics and thermodynamics of cavitation in various fluids; Test facilities and methods of cavitation research and testing; Special instrumentation for cavitation studies, and standards and recommendations for cavitation or erosion

  16. System for automatic detection of lung nodules exhibiting growth

    Science.gov (United States)

    Novak, Carol L.; Shen, Hong; Odry, Benjamin L.; Ko, Jane P.; Naidich, David P.

    2004-05-01

    Lung nodules that exhibit growth over time are considered highly suspicious for malignancy. We present a completely automated system for detection of growing lung nodules, using initial and follow-up multi-slice CT studies. The system begins with automatic detection of lung nodules in the later CT study, generating a preliminary list of candidate nodules. Next an automatic system for registering locations in two studies matches each candidate in the later study to its corresponding position in the earlier study. Then a method for automatic segmentation of lung nodules is applied to each candidate and its matching location, and the computed volumes are compared. The output of the system is a list of nodule candidates that are new or have exhibited volumetric growth since the previous scan. In a preliminary test of 10 patients examined by two radiologists, the automatic system identified 18 candidates as growing nodules. 7 (39%) of these corresponded to validated nodules or other focal abnormalities that exhibited growth. 4 of the 7 true detections had not been identified by either of the radiologists during their initial examinations of the studies. This technique represents a powerful method of surveillance that may reduce the probability of missing subtle or early malignant disease.

  17. Computerized detection of lung nodules in digital chest radiographs

    International Nuclear Information System (INIS)

    Giger, M.L.; Doi, K.; MacMahon, H.

    1987-01-01

    Detection of cancerous lung nodules in chest radiographs is one of the more important tasks performed by a radiologist. In addition, the ''miss rate'' associated with the radiographic detection of lung nodules is approximately 30%. A computerized scheme that alerts the radiologist to possible locations of lung nodules should allow this number of false-negative diagnoses to be reduced. The authors are developing a computer-aided nodule detection scheme based on a difference image approach. They attempt to eliminate the camouflaging background structure of the normal lung anatomy by creating, from a single-projection chest image, two images: one in which the signal-to-noise ratio (SNR) of the nodule is maximized and another in which that SNR is suppressed while the processed background remains essentially the same. Thus, the difference between these two processed images should consist of the nodule superimposed on a relatively uniform background in which the detection task may be simplified. This difference image approach is fundamentally different from conventional subtraction techniques (e.g., temporal or dual-energy subtraction) in that the two images which are subtracted arise from the same single-projection chest radiograph. Once the difference image is obtained, thresholding is performed along with tests for circularity, size and growth in order to extract the nodules. It should be noted that once an original chest image is input to the computer the nodule detection process is totally automated

  18. Radiographic test phantom for computed tomographic lung nodule analysis

    International Nuclear Information System (INIS)

    Zerhouni, E.A.

    1987-01-01

    This patent describes a method for evaluating a computed tomograph scan of a nodule in a lung of a human or non-human animal. The method comprises generating a computer tomograph of a transverse section of the animal containing lung and nodule tissue, and generating a second computer tomograph of a test phantom comprising a device which simulates the transverse section of the animal. The tissue simulating portions of the device are constructed of materials having radiographic densities substantially identical to those of the corresponding tissue in the simulated transverse section of the animal and have voids therein which simulate, in size and shape, the lung cavities in the transverse section and which contain a test reference nodule constructed of a material of predetermined radiographic density which simulates in size, shape and position within a lung cavity void of the test phantom the nodule in the transverse section of the animal and comparing the respective tomographs

  19. Lung Nodule Detection in CT Images using Neuro Fuzzy Classifier

    Directory of Open Access Journals (Sweden)

    M. Usman Akram

    2013-07-01

    Full Text Available Automated lung cancer detection using computer aided diagnosis (CAD is an important area in clinical applications. As the manual nodule detection is very time consuming and costly so computerized systems can be helpful for this purpose. In this paper, we propose a computerized system for lung nodule detection in CT scan images. The automated system consists of two stages i.e. lung segmentation and enhancement, feature extraction and classification. The segmentation process will result in separating lung tissue from rest of the image, and only the lung tissues under examination are considered as candidate regions for detecting malignant nodules in lung portion. A feature vector for possible abnormal regions is calculated and regions are classified using neuro fuzzy classifier. It is a fully automatic system that does not require any manual intervention and experimental results show the validity of our system.

  20. Lung nodule volumetry: segmentation algorithms within the same software package cannot be used interchangeably.

    NARCIS (Netherlands)

    Ashraf, H.; Hoop, B.J. de; Shaker, S.B.; Dirksen, A.; Bach, K.S.; Hansen, H.; Prokop, M.; Pedersen, J.H.

    2010-01-01

    OBJECTIVE: We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms. METHODS: In a lung cancer screening trial, 188 baseline nodules >5 mm were identified. Including follow-ups, these nodules formed a study-set of 545 nodules. Nodules were

  1. Lung nodule volumetry: segmentation algorithms within the same software package cannot be used interchangeably

    DEFF Research Database (Denmark)

    Ashraf, Haseem; de Hoop, B; Shaker, S B

    2010-01-01

    We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms.......We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms....

  2. Cavitation

    CERN Document Server

    Young, F Ronald

    1999-01-01

    First published by McGraw-Hill in 1989, this book provides a unified treatment of cavitation, a phenomenon which extends across the boundaries of many fields. The approach is wide-ranging and the aim is to give due consideration to the many aspects of cavitation in proportion to their importance. Particular attention is paid to the diverse situations in which cavitation occurs and to its practical applications.

  3. What to Do with All of These Lung Nodules?

    Directory of Open Access Journals (Sweden)

    Dmitry Rozenberg

    2014-01-01

    Full Text Available Caplan syndrome is a rare entity that is specific to rheumatoid arthritis and presents with multiple, well-defined necrotic nodules in patients with occupational dust exposure. The present report describes a case of Caplan syndrome involving a 71-year-old man with a known diagnosis of seropositive rheumatoid arthritis who presented to the authors’ centre with a five-year history of multiple, bilateral cavitary lung nodules with mild dyspnea on exertion. He was an ex-smoker (30 pack-years and had previously worked with silica. The case highlights the clinical, radiological and pathological features of this syndrome and outlines the importance of considering a broad differential in the management of pulmonary nodules, especially in patients with rheumatoid arthritis.

  4. Radiofrequency thermal ablation of a metastatic lung nodule

    Energy Technology Data Exchange (ETDEWEB)

    Highland, Adrian M. [Department of Clinical Radiology, Hull Royal Infirmary, Anlaby Road, Hull, HU3 2JZ (United Kingdom); Mack, Paul [Diana Princess of Wales Hospital, Scartho Road, Grimsby, DN33 2BA (United Kingdom); Breen, David J. [Department of Radiology, Southampton University Hospitals, Tremona Road, Southampton, SO16 6YD (United Kingdom)

    2002-07-01

    Pulmonary metastases are a common finding in patients with colonic adenocarcinoma. We report the treatment of a metastatic lung nodule with radiofrequency (RF) ablation under CT guidance. This case illustrates the use of RF ablation in a patient in whom surgical resection was no longer possible and where chemotherapy was unlikely to produce benefit. This technique may offer a viable method of cytoreduction when other treatments have not succeeded. (orig.)

  5. Radiofrequency thermal ablation of a metastatic lung nodule

    International Nuclear Information System (INIS)

    Highland, Adrian M.; Mack, Paul; Breen, David J.

    2002-01-01

    Pulmonary metastases are a common finding in patients with colonic adenocarcinoma. We report the treatment of a metastatic lung nodule with radiofrequency (RF) ablation under CT guidance. This case illustrates the use of RF ablation in a patient in whom surgical resection was no longer possible and where chemotherapy was unlikely to produce benefit. This technique may offer a viable method of cytoreduction when other treatments have not succeeded. (orig.)

  6. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Wille, Mathilde Marie Winkler

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure...... that will yield improvements in both diagnosis and treatment. The standard-of-care surgical treatment of early lung cancer is still minimally invasive lobectomy with systematic lymph node dissection. However, recent research has shown that some GGO lesions may be treated with sublobar resections; these findings......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...

  7. Pulmonary Nodule Management in Lung Cancer Screening: A Pictorial Review of Lung-RADS Version 1.0.

    Science.gov (United States)

    Godoy, Myrna C B; Odisio, Erika G L C; Truong, Mylene T; de Groot, Patricia M; Shroff, Girish S; Erasmus, Jeremy J

    2018-05-01

    The number of screening-detected lung nodules is expected to increase as low-dose computed tomography screening is implemented nationally. Standardized guidelines for image acquisition, interpretation, and screen-detected nodule workup are essential to ensure a high standard of medical care and that lung cancer screening is implemented safely and cost effectively. In this article, we review the current guidelines for pulmonary nodule management in the lung cancer screening setting. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Evaluation of radiographic imaging techniques in lung nodule detection

    International Nuclear Information System (INIS)

    Ho, J.T.; Kruger, R.A.

    1989-01-01

    Dual-energy radiography appears to be the most effective technique to address bone superposition that compromises conventional chest radiography. A dual-energy, single-exposure, film-based technique was compared with a dual-energy, dual-exposure technique and conventional chest radiography in a simulated lung nodule detection study. Observers detected more nodules on images produced by dual-energy techniques than on images produced by conventional chest radiography. The difference between dual-energy and conventional chest radiography is statistically significant and the difference between dual-energy, dual-exposure and single-exposure techniques is statistically insignificant. The single-exposure technique has the potential to replace the dual-exposure technique in future clinical application

  9. A COMPREHENSIVE FRAMEWORK FOR AUTOMATIC DETECTION OF PULMONARY NODULES IN LUNG CT IMAGES

    Directory of Open Access Journals (Sweden)

    Mehdi Alilou

    2014-03-01

    Full Text Available Solitary pulmonary nodules may indicate an early stage of lung cancer. Hence, the early detection of nodules is the most efficient way for saving the lives of patients. The aim of this paper is to present a comprehensive Computer Aided Diagnosis (CADx framework for detection of the lung nodules in computed tomography images. The four major components of the developed framework are lung segmentation, identification of candidate nodules, classification and visualization. The process starts with segmentation of lung regions from the thorax. Then, inside the segmented lung regions, candidate nodules are identified using an approach based on multiple thresholds followed by morphological opening and 3D region growing algorithm. Finally, a combination of a rule-based procedure and support vector machine classifier (SVM is utilized to classify the candidate nodules. The proposed CADx method was validated on CT images of 60 patients, containing the total of 211 nodules, selected from the publicly available Lung Image Database Consortium (LIDC image dataset. Comparing to the other state of the art methods, the proposed framework demonstrated acceptable detection performance (Sensitivity: 0.80; Fp/Scan: 3.9. Furthermore, we visualize a range of anatomical structures including the 3D lung structure and the segmented nodules along with the Maximum Intensity Projection (MIP volume rendering method that will enable the radiologists to accurately and easily estimate the distance between the lung structures and the nodules which are frequently difficult at best to recognize from CT images.

  10. Accuracy of lung nodule volumetry in low-dose CT with iterative reconstruction: an anthropomorphic thoracic phantom study.

    Science.gov (United States)

    Doo, K W; Kang, E-Y; Yong, H S; Woo, O H; Lee, K Y; Oh, Y-W

    2014-09-01

    The purpose of this study was to assess accuracy of lung nodule volumetry in low-dose CT with application of iterative reconstruction (IR) according to nodule size, nodule density and CT tube currents, using artificial lung nodules within an anthropomorphic thoracic phantom. Eight artificial nodules (four diameters: 5, 8, 10 and 12 mm; two CT densities: -630 HU that represents ground-glass nodule and +100 HU that represents solid nodule) were randomly placed inside a thoracic phantom. Scans were performed with tube current-time product to 10, 20, 30 and 50 mAs. Images were reconstructed with IR and filtered back projection (FBP). We compared volume estimates to a reference standard and calculated the absolute percentage error (APE). The APE of all nodules was significantly lower when IR was used than with FBP (7.5 ± 4.7% compared with 9.0 ±6.9%; p volumetry in low-dose CT by application of IR showed reliable accuracy in a phantom study. Lung nodule volumetry can be reliably applicable to all lung nodules including small, ground-glass nodules even in ultra-low-dose CT with application of IR. IR significantly improved the accuracy of lung nodule volumetry compared with FBP particularly for ground-glass (-630 HU) nodules. Volumetry in low-dose CT can be utilized in patient with lung nodule work-up, and IR has benefit for small, ground-glass lung nodules in low-dose CT.

  11. Computer-aided detection of lung nodules in digital chest radiographs

    International Nuclear Information System (INIS)

    Giger, M.L.; Doi, K.; MacMahon, H.M.

    1986-01-01

    The authors are developing an automated method to detect lung nodules by eliminating the ''camouflaging: effect of the lung background. In order to increase the conspicuity of the nodules, we created, from a single chest radiograph, two images: one in which the signal-to-noise ratio (S/N) of the nodule is maximized and another in which that S/N is suppressed. The difference between these two processed images was subjected to feature-extraction technique in order to isolate the nodules. The detection accuracy of the computer-aided detection scheme, as compared with unaided radiologists' performance, was determined using receiver operating characteristic curve analysis

  12. The calcified lung nodule: What does it mean?

    Directory of Open Access Journals (Sweden)

    Khan Ali

    2010-01-01

    Full Text Available The aim of this review is to present a pictorial essay emphasizing the various patterns of calcification in pulmonary nodules (PN to aid diagnosis and to discuss the differential diagnosis and the pathogenesis where it is known. The imaging evaluation of PN is based on clinical history, size, distribution and the gross appearance of the nodule as well as feasibility of obtaining a tissue diagnosis. Imaging is instrumental in the management of PN and one should strive not only to identify small malignant tumors with high survival rates but to spare patients with benign PN from undergoing unnecessary surgery. The review emphasizes how to achieve these goals. One of the most reliable imaging features of a benign lesion is a benign pattern of calcification and periodic follow-up with computed tomography showing no growth for 2 years. Calcification in PN is generally considered as a pointer toward a possible benign disease. However, as we show here, calcification in PN as a criterion to determine benign nature is fallacious and can be misleading. The differential considerations of a calcified lesion include calcified granuloma, hamartoma, carcinoid, osteosarcoma, chondrosarcoma and lung metastases or a primary bronchogenic carcinoma among others. We describe and illustrate different patterns of calcification as seen in PN on imaging.

  13. Comparison of digital tomosynthesis and computed tomography for lung nodule detection in SOS screening program.

    Science.gov (United States)

    Grosso, Maurizio; Priotto, Roberto; Ghirardo, Donatella; Talenti, Alberto; Roberto, Emanuele; Bertolaccini, Luca; Terzi, Alberto; Chauvie, Stéphane

    2017-08-01

    To compare the lung nodules' detection of digital tomosynthesis (DTS) and computed tomography (CT) in the context of the SOS (Studio OSservazionale) prospective screening program for lung cancer detection. One hundred and thirty-two of the 1843 subjects enrolled in the SOS study underwent CT because non-calcified nodules with diameters larger than 5 mm and/or multiple nodules were present in DTS. Two expert radiologists reviewed the exams classifying the nodules based on their radiological appearance and their dimension. LUNG-RADS classification was applied to compare receiver operator characteristics curve between CT and DTS with respect to final diagnosis. CT was used as gold standard. DTS and CT detected 208 and 179 nodules in the 132 subjects, respectively. Of these 208 nodules, 189 (91%) were solid, partially solid, and ground glass opacity. CT confirmed 140/189 (74%) of these nodules but found 4 nodules that were not detected by DTS. DTS and CT were concordant in 62% of the cases applying the 5-point LUNG-RADS scale. The concordance rose to 86% on a suspicious/non-suspicious binary scale. The areas under the curve in receiver operator characteristics were 0.89 (95% CI 0.83-0.94) and 0.80 (95% CI 0.72-0.89) for CT and DTS, respectively. The mean effective dose was 0.09 ± 0.04 mSv for DTS and 4.90 ± 1.20 mSv for CT. The use of a common classification for nodule detection in DTS and CT helps in comparing the two technologies. DTS detected and correctly classified 74% of the nodules seen by CT but lost 4 nodules identified by CT. Concordance between DTS and CT rose to 86% of the nodules when considering LUNG-RADS on a binary scale.

  14. Evaluation of an improved method of simulating lung nodules in chest tomosynthesis

    International Nuclear Information System (INIS)

    Svalkvist, Angelica; Allansdotter Johnsson, Aase; Vikgren, Jenny

    2012-01-01

    Background Simulated pathology is a valuable complement to clinical images in studies aiming at evaluating an imaging technique. In order for a study using simulated pathology to be valid, it is important that the simulated pathology in a realistic way reflect the characteristics of real pathology. Purpose To perform a thorough evaluation of a nodule simulation method for chest tomosynthesis, comparing the detection rate and appearance of the artificial nodules with those of real nodules in an observer performance experiment. Material and Methods A cohort consisting of 64 patients, 38 patients with a total of 129 identified pulmonary nodules and 26 patients without identified pulmonary nodules, was used in the study. Simulated nodules, matching the real clinically found pulmonary nodules by size, attenuation, and location, were created and randomly inserted into the tomosynthesis section images of the patients. Three thoracic radiologists and one radiology resident reviewed the images in an observer performance study divided into two parts. The first part included nodule detection and the second part included rating of the visual appearance of the nodules. The results were evaluated using a modified receiver-operating characteristic (ROC) analysis. Results The sensitivities for real and simulated nodules were comparable, as the area under the modified ROC curve (AUC) was close to 0.5 for all observers (range, 0.43-0.55). Even though the ratings of visual appearance for real and simulated nodules overlapped considerably, the statistical analysis revealed that the observers to were able to separate simulated nodules from real nodules (AUC values range 0.70-0.74). Conclusion The simulation method can be used to create artificial lung nodules that have similar detectability as real nodules in chest tomosynthesis, although experienced thoracic radiologists may be able to distinguish them from real nodules

  15. Lung nodule volumetry: segmentation algorithms within the same software package cannot be used interchangeably

    Energy Technology Data Exchange (ETDEWEB)

    Ashraf, H.; Bach, K.S.; Hansen, H. [Copenhagen University, Department of Radiology, Gentofte Hospital, Hellerup (Denmark); Hoop, B. de [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands); Shaker, S.B.; Dirksen, A. [Copenhagen University, Department of Respiratory Medicine, Gentofte Hospital, Hellerup (Denmark); Prokop, M. [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands); Radboud University Nijmegen, Department of Radiology, Nijmegen (Netherlands); Pedersen, J.H. [Copenhagen University, Department of Cardiothoracic Surgery RT, Rigshospitalet, Copenhagen (Denmark)

    2010-08-15

    We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms. In a lung cancer screening trial, 188 baseline nodules >5 mm were identified. Including follow-ups, these nodules formed a study-set of 545 nodules. Nodules were independently double read by two readers using commercially available volumetry software. The software offers readers three different analysing algorithms. We compared the inter-observer variability of nodule volumetry when the readers used the same and different algorithms. Both readers were able to correctly segment and measure 72% of nodules. In 80% of these cases, the readers chose the same algorithm. When readers used the same algorithm, exactly the same volume was measured in 50% of readings and a difference of >25% was observed in 4%. When the readers used different algorithms, 83% of measurements showed a difference of >25%. Modern volumetric software failed to correctly segment a high number of screen detected nodules. While choosing a different algorithm can yield better segmentation of a lung nodule, reproducibility of volumetric measurements deteriorates substantially when different algorithms were used. It is crucial even in the same software package to choose identical parameters for follow-up. (orig.)

  16. Lung nodule volumetry: segmentation algorithms within the same software package cannot be used interchangeably

    International Nuclear Information System (INIS)

    Ashraf, H.; Bach, K.S.; Hansen, H.; Hoop, B. de; Shaker, S.B.; Dirksen, A.; Prokop, M.; Pedersen, J.H.

    2010-01-01

    We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms. In a lung cancer screening trial, 188 baseline nodules >5 mm were identified. Including follow-ups, these nodules formed a study-set of 545 nodules. Nodules were independently double read by two readers using commercially available volumetry software. The software offers readers three different analysing algorithms. We compared the inter-observer variability of nodule volumetry when the readers used the same and different algorithms. Both readers were able to correctly segment and measure 72% of nodules. In 80% of these cases, the readers chose the same algorithm. When readers used the same algorithm, exactly the same volume was measured in 50% of readings and a difference of >25% was observed in 4%. When the readers used different algorithms, 83% of measurements showed a difference of >25%. Modern volumetric software failed to correctly segment a high number of screen detected nodules. While choosing a different algorithm can yield better segmentation of a lung nodule, reproducibility of volumetric measurements deteriorates substantially when different algorithms were used. It is crucial even in the same software package to choose identical parameters for follow-up. (orig.)

  17. Computer-aided diagnosis of lung cancer: the effect of training data sets on classification accuracy of lung nodules

    Science.gov (United States)

    Gong, Jing; Liu, Ji-Yu; Sun, Xi-Wen; Zheng, Bin; Nie, Sheng-Dong

    2018-02-01

    This study aims to develop a computer-aided diagnosis (CADx) scheme for classification between malignant and benign lung nodules, and also assess whether CADx performance changes in detecting nodules associated with early and advanced stage lung cancer. The study involves 243 biopsy-confirmed pulmonary nodules. Among them, 76 are benign, 81 are stage I and 86 are stage III malignant nodules. The cases are separated into three data sets involving: (1) all nodules, (2) benign and stage I malignant nodules, and (3) benign and stage III malignant nodules. A CADx scheme is applied to segment lung nodules depicted on computed tomography images and we initially computed 66 3D image features. Then, three machine learning models namely, a support vector machine, naïve Bayes classifier and linear discriminant analysis, are separately trained and tested by using three data sets and a leave-one-case-out cross-validation method embedded with a Relief-F feature selection algorithm. When separately using three data sets to train and test three classifiers, the average areas under receiver operating characteristic curves (AUC) are 0.94, 0.90 and 0.99, respectively. When using the classifiers trained using data sets with all nodules, average AUC values are 0.88 and 0.99 for detecting early and advanced stage nodules, respectively. AUC values computed from three classifiers trained using the same data set are consistent without statistically significant difference (p  >  0.05). This study demonstrates (1) the feasibility of applying a CADx scheme to accurately distinguish between benign and malignant lung nodules, and (2) a positive trend between CADx performance and cancer progression stage. Thus, in order to increase CADx performance in detecting subtle and early cancer, training data sets should include more diverse early stage cancer cases.

  18. Digital tomosynthesis for evaluating metastatic lung nodules: nodule visibility, learning curves, and reading times.

    Science.gov (United States)

    Lee, Kyung Hee; Goo, Jin Mo; Lee, Sang Min; Park, Chang Min; Bahn, Young Eun; Kim, Hyungjin; Song, Yong Sub; Hwang, Eui Jin

    2015-01-01

    To evaluate nodule visibility, learning curves, and reading times for digital tomosynthesis (DT). We included 80 patients who underwent computed tomography (CT) and DT before pulmonary metastasectomy. One experienced chest radiologist annotated all visible nodules on thin-section CT scans using computer-aided detection software. Two radiologists used CT as the reference standard and retrospectively graded the visibility of nodules on DT. Nodule detection performance was evaluated in four sessions of 20 cases each by six readers. After each session, readers were unblinded to the DT images by revealing the true-positive markings and were instructed to self-analyze their own misreads. Receiver-operating-characteristic curves were determined. Among 414 nodules on CT, 53.3% (221/414) were visible on DT. The main reason for not seeing a nodule on DT was small size (93.3%, ≤ 5 mm). DT revealed a substantial number of malignant nodules (84.1%, 143/170). The proportion of malignant nodules among visible nodules on DT was significantly higher (64.7%, 143/221) than that on CT (41.1%, 170/414) (p 0.8, and the average detection rate for malignant nodules was 85% (210/246). The inter-session analysis of the AUC showed no significant differences among the readers, and the detection rate for malignant nodules did not differ across sessions. A slight improvement in reading times was observed. Most malignant nodules > 5 mm were visible on DT. As nodule detection performance was high from the initial session, DT may be readily applicable for radiology residents and board-certified radiologists.

  19. Digital tomosynthesis for evaluating metastatic lung nodules: Nodule visibility, learning curves, and reading times

    International Nuclear Information System (INIS)

    Lee, Kyung Hee; Goo, Jin Mo; Lee, Sang Min; Park, Chang Min; Bahn, Young Eun; Kim, Hyung Jin; Song, Yong Sub; Hwang, Eui Jin

    2015-01-01

    To evaluate nodule visibility, learning curves, and reading times for digital tomosynthesis (DT). We included 80 patients who underwent computed tomography (CT) and DT before pulmonary metastasectomy. One experienced chest radiologist annotated all visible nodules on thin-section CT scans using computer-aided detection software. Two radiologists used CT as the reference standard and retrospectively graded the visibility of nodules on DT. Nodule detection performance was evaluated in four sessions of 20 cases each by six readers. After each session, readers were unblinded to the DT images by revealing the true-positive markings and were instructed to self-analyze their own misreads. Receiver-operating-characteristic curves were determined. Among 414 nodules on CT, 53.3% (221/414) were visible on DT. The main reason for not seeing a nodule on DT was small size (93.3%, < or = 5 mm). DT revealed a substantial number of malignant nodules (84.1%, 143/170). The proportion of malignant nodules among visible nodules on DT was significantly higher (64.7%, 143/221) than that on CT (41.1%, 170/414) (p < 0.001). Area under the curve (AUC) values at the initial session were > 0.8, and the average detection rate for malignant nodules was 85% (210/246). The inter-session analysis of the AUC showed no significant differences among the readers, and the detection rate for malignant nodules did not differ across sessions. A slight improvement in reading times was observed. Most malignant nodules > 5 mm were visible on DT. As nodule detection performance was high from the initial session, DT may be readily applicable for radiology residents and board-certified radiologists.

  20. Digital tomosynthesis for evaluating metastatic lung nodules: Nodule visibility, learning curves, and reading times

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Hee; Goo, Jin Mo; Lee, Sang Min; Park, Chang Min; Bahn, Young Eun; Kim, Hyung Jin; Song, Yong Sub; Hwang, Eui Jin [Dept. of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2015-04-15

    To evaluate nodule visibility, learning curves, and reading times for digital tomosynthesis (DT). We included 80 patients who underwent computed tomography (CT) and DT before pulmonary metastasectomy. One experienced chest radiologist annotated all visible nodules on thin-section CT scans using computer-aided detection software. Two radiologists used CT as the reference standard and retrospectively graded the visibility of nodules on DT. Nodule detection performance was evaluated in four sessions of 20 cases each by six readers. After each session, readers were unblinded to the DT images by revealing the true-positive markings and were instructed to self-analyze their own misreads. Receiver-operating-characteristic curves were determined. Among 414 nodules on CT, 53.3% (221/414) were visible on DT. The main reason for not seeing a nodule on DT was small size (93.3%, < or = 5 mm). DT revealed a substantial number of malignant nodules (84.1%, 143/170). The proportion of malignant nodules among visible nodules on DT was significantly higher (64.7%, 143/221) than that on CT (41.1%, 170/414) (p < 0.001). Area under the curve (AUC) values at the initial session were > 0.8, and the average detection rate for malignant nodules was 85% (210/246). The inter-session analysis of the AUC showed no significant differences among the readers, and the detection rate for malignant nodules did not differ across sessions. A slight improvement in reading times was observed. Most malignant nodules > 5 mm were visible on DT. As nodule detection performance was high from the initial session, DT may be readily applicable for radiology residents and board-certified radiologists.

  1. Incidentally detected lung nodules: clinical predictors of adherence to fleischner society surveillance guidelines.

    LENUS (Irish Health Repository)

    Ridge, Carole A

    2014-02-28

    The objective of this study was to determine adherence to incidentally detected lung nodule computed tomographic (CT) surveillance recommendations and identify demographic and clinical factors that increase the likelihood of CT surveillance.

  2. Towards automatic pulmonary nodule management in lung cancer screening with deep learning.

    Science.gov (United States)

    Ciompi, Francesco; Chung, Kaman; van Riel, Sarah J; Setio, Arnaud Arindra Adiyoso; Gerke, Paul K; Jacobs, Colin; Scholten, Ernst Th; Schaefer-Prokop, Cornelia; Wille, Mathilde M W; Marchianò, Alfonso; Pastorino, Ugo; Prokop, Mathias; van Ginneken, Bram

    2017-04-19

    The introduction of lung cancer screening programs will produce an unprecedented amount of chest CT scans in the near future, which radiologists will have to read in order to decide on a patient follow-up strategy. According to the current guidelines, the workup of screen-detected nodules strongly relies on nodule size and nodule type. In this paper, we present a deep learning system based on multi-stream multi-scale convolutional networks, which automatically classifies all nodule types relevant for nodule workup. The system processes raw CT data containing a nodule without the need for any additional information such as nodule segmentation or nodule size and learns a representation of 3D data by analyzing an arbitrary number of 2D views of a given nodule. The deep learning system was trained with data from the Italian MILD screening trial and validated on an independent set of data from the Danish DLCST screening trial. We analyze the advantage of processing nodules at multiple scales with a multi-stream convolutional network architecture, and we show that the proposed deep learning system achieves performance at classifying nodule type that surpasses the one of classical machine learning approaches and is within the inter-observer variability among four experienced human observers.

  3. Intelligent Recognition of Lung Nodule Combining Rule-based and C-SVM Classifiers

    Directory of Open Access Journals (Sweden)

    Bin Li

    2011-10-01

    Full Text Available Computer-aided detection(CAD system for lung nodules plays the important role in the diagnosis of lung cancer. In this paper, an improved intelligent recognition method of lung nodule in HRCT combing rule-based and costsensitive support vector machine(C-SVM classifiers is proposed for detecting both solid nodules and ground-glass opacity(GGO nodules(part solid and nonsolid. This method consists of several steps. Firstly, segmentation of regions of interest(ROIs, including pulmonary parenchyma and lung nodule candidates, is a difficult task. On one side, the presence of noise lowers the visibility of low-contrast objects. On the other side, different types of nodules, including small nodules, nodules connecting to vasculature or other structures, part-solid or nonsolid nodules, are complex, noisy, weak edge or difficult to define the boundary. In order to overcome the difficulties of obvious boundary-leak and slow evolvement speed problem in segmentatioin of weak edge, an overall segmentation method is proposed, they are: the lung parenchyma is extracted based on threshold and morphologic segmentation method; the image denoising and enhancing is realized by nonlinear anisotropic diffusion filtering(NADF method;candidate pulmonary nodules are segmented by the improved C-V level set method, in which the segmentation result of EM-based fuzzy threshold method is used as the initial contour of active contour model and a constrained energy term is added into the PDE of level set function. Then, lung nodules are classified by using the intelligent classifiers combining rules and C-SVM. Rule-based classification is first used to remove easily dismissible nonnodule objects, then C-SVM classification are used to further classify nodule candidates and reduce the number of false positive(FP objects. In order to increase the efficiency of SVM, an improved training method is used to train SVM, which uses the grid search method to search the optimal parameters

  4. Intelligent Recognition of Lung Nodule Combining Rule-based and C-SVM Classifiers

    Directory of Open Access Journals (Sweden)

    Bin Li

    2012-02-01

    Full Text Available Computer-aided detection(CAD system for lung nodules plays the important role in the diagnosis of lung cancer. In this paper, an improved intelligent recognition method of lung nodule in HRCT combing rule-based and cost-sensitive support vector machine(C-SVM classifiers is proposed for detecting both solid nodules and ground-glass opacity(GGO nodules(part solid and nonsolid. This method consists of several steps. Firstly, segmentation of regions of interest(ROIs, including pulmonary parenchyma and lung nodule candidates, is a difficult task. On one side, the presence of noise lowers the visibility of low-contrast objects. On the other side, different types of nodules, including small nodules, nodules connecting to vasculature or other structures, part-solid or nonsolid nodules, are complex, noisy, weak edge or difficult to define the boundary. In order to overcome the difficulties of obvious boundary-leak and slow evolvement speed problem in segmentatioin of weak edge, an overall segmentation method is proposed, they are: the lung parenchyma is extracted based on threshold and morphologic segmentation method; the image denoising and enhancing is realized by nonlinear anisotropic diffusion filtering(NADF method; candidate pulmonary nodules are segmented by the improved C-V level set method, in which the segmentation result of EM-based fuzzy threshold method is used as the initial contour of active contour model and a constrained energy term is added into the PDE of level set function. Then, lung nodules are classified by using the intelligent classifiers combining rules and C-SVM. Rule-based classification is first used to remove easily dismissible nonnodule objects, then C-SVM classification are used to further classify nodule candidates and reduce the number of false positive(FP objects. In order to increase the efficiency of SVM, an improved training method is used to train SVM, which uses the grid search method to search the optimal

  5. Detection of lung nodules with low-dose spiral CT: comparison with conventional dose CT

    International Nuclear Information System (INIS)

    Zhu Tianzhao; Tang Guangjian; Jiang Xuexiang

    2004-01-01

    Objective: To investigate the effect of reducing scan dose on the lung nodules detection rate by scanning a lung nodule model at low dose and conventional dose. Methods: The lung and the thoracic cage were simulated by using a cyst filled with water surrounded by a roll bandage. Flour, butter, and paraffin wax were mixed together by a certain ratio to simulate lung nodules of 10 mm and 5 mm in diameter with the CT values ranging from -10 to 50 HU. Conventional-dose scan (240 mA, 140 kV) and low-dose scan of three different levels (43 mA, 140 kV; 50 mA, 120 kV; 75 mA, 80 kV) together with three different pitches (1.0, 1.5, and 2.0) were performed. The images of the simulated nodules were combined with the CT images of a normal adult's upper, middle, and inferior lung. Three radiologists read the images and the number of the nodules they detected including both the real ones and the false-positive ones was calculated to investigate weather there was any difference among different doses, pitch groups, and different locations. Results: The detection rate of the 10 mm and 5 mm nodules was 100% and 89.6% respectively by the low-dose scan. There was no difference between low-dose and conventional-dose CT (χ 2 =0.6907, P>0.70). The detection rate of 5 mm nodules declined when large pitch was used. Conclusion: The detection rates of 10 mm and 5 mm nodules had no difference between low-dose CT and conventional-dose CT. As the pitch augmented, the detection rate for the nodules declined

  6. Ant Colony Optimization Approaches to Clustering of Lung Nodules from CT Images

    Directory of Open Access Journals (Sweden)

    Ravichandran C. Gopalakrishnan

    2014-01-01

    Full Text Available Lung cancer is becoming a threat to mankind. Applying machine learning algorithms for detection and segmentation of irregular shaped lung nodules remains a remarkable milestone in CT scan image analysis research. In this paper, we apply ACO algorithm for lung nodule detection. We have compared the performance against three other algorithms, namely, Otsu algorithm, watershed algorithm, and global region based segmentation. In addition, we suggest a novel approach which involves variations of ACO, namely, refined ACO, logical ACO, and variant ACO. Variant ACO shows better reduction in false positives. In addition we propose black circular neighborhood approach to detect nodule centers from the edge detected image. Genetic algorithm based clustering is performed to cluster the nodules based on intensity, shape, and size. The performance of the overall approach is compared with hierarchical clustering to establish the improvisation in the proposed approach.

  7. Accuracy of lung nodule density on HRCT: analysis by PSF-based image simulation.

    Science.gov (United States)

    Ohno, Ken; Ohkubo, Masaki; Marasinghe, Janaka C; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

    2012-11-08

    A computed tomography (CT) image simulation technique based on the point spread function (PSF) was applied to analyze the accuracy of CT-based clinical evaluations of lung nodule density. The PSF of the CT system was measured and used to perform the lung nodule image simulation. Then, the simulated image was resampled at intervals equal to the pixel size and the slice interval found in clinical high-resolution CT (HRCT) images. On those images, the nodule density was measured by placing a region of interest (ROI) commonly used for routine clinical practice, and comparing the measured value with the true value (a known density of object function used in the image simulation). It was quantitatively determined that the measured nodule density depended on the nodule diameter and the image reconstruction parameters (kernel and slice thickness). In addition, the measured density fluctuated, depending on the offset between the nodule center and the image voxel center. This fluctuation was reduced by decreasing the slice interval (i.e., with the use of overlapping reconstruction), leading to a stable density evaluation. Our proposed method of PSF-based image simulation accompanied with resampling enables a quantitative analysis of the accuracy of CT-based evaluations of lung nodule density. These results could potentially reveal clinical misreadings in diagnosis, and lead to more accurate and precise density evaluations. They would also be of value for determining the optimum scan and reconstruction parameters, such as image reconstruction kernels and slice thicknesses/intervals.

  8. Early detection of lung cancer from CT images: nodule segmentation and classification using deep learning

    Science.gov (United States)

    Sharma, Manu; Bhatt, Jignesh S.; Joshi, Manjunath V.

    2018-04-01

    Lung cancer is one of the most abundant causes of the cancerous deaths worldwide. It has low survival rate mainly due to the late diagnosis. With the hardware advancements in computed tomography (CT) technology, it is now possible to capture the high resolution images of lung region. However, it needs to be augmented by efficient algorithms to detect the lung cancer in the earlier stages using the acquired CT images. To this end, we propose a two-step algorithm for early detection of lung cancer. Given the CT image, we first extract the patch from the center location of the nodule and segment the lung nodule region. We propose to use Otsu method followed by morphological operations for the segmentation. This step enables accurate segmentation due to the use of data-driven threshold. Unlike other methods, we perform the segmentation without using the complete contour information of the nodule. In the second step, a deep convolutional neural network (CNN) is used for the better classification (malignant or benign) of the nodule present in the segmented patch. Accurate segmentation of even a tiny nodule followed by better classification using deep CNN enables the early detection of lung cancer. Experiments have been conducted using 6306 CT images of LIDC-IDRI database. We achieved the test accuracy of 84.13%, with the sensitivity and specificity of 91.69% and 73.16%, respectively, clearly outperforming the state-of-the-art algorithms.

  9. Computer-Aided Detection of Malignant Lung Nodules on Chest Radiographs: Effect on Observers' Performance

    International Nuclear Information System (INIS)

    Lee, Kyung Hee; Goo, Jin Mo; Park, Chang Min; Lee, Hyun Ju; Jin, Kwang Nam

    2012-01-01

    To evaluate the effect of computer-aided detection (CAD) system on observer performance in the detection of malignant lung nodules on chest radiograph. Two hundred chest radiographs (100 normal and 100 abnormal with malignant solitary lung nodules) were evaluated. With CT and histological confirmation serving as a reference, the mean nodule size was 15.4 mm (range, 7-20 mm). Five chest radiologists and five radiology residents independently interpreted both the original radiographs and CAD output images using the sequential testing method. The performances of the observers for the detection of malignant nodules with and without CAD were compared using the jackknife free-response receiver operating characteristic analysis. Fifty-nine nodules were detected by the CAD system with a false positive rate of 1.9 nodules per case. The detection of malignant lung nodules significantly increased from 0.90 to 0.92 for a group of observers, excluding one first-year resident (p = 0.04). When lowering the confidence score was not allowed, the average figure of merit also increased from 0.90 to 0.91 (p = 0.04) for all observers after a CAD review. On average, the sensitivities with and without CAD were 87% and 84%, respectively; the false positive rates per case with and without CAD were 0.19 and 0.17, respectively. The number of additional malignancies detected following true positive CAD marks ranged from zero to seven for the various observers. The CAD system may help improve observer performance in detecting malignant lung nodules on chest radiographs and contribute to a decrease in missed lung cancer.

  10. Automated system for lung nodules classification based on wavelet feature descriptor and support vector machine.

    Science.gov (United States)

    Madero Orozco, Hiram; Vergara Villegas, Osslan Osiris; Cruz Sánchez, Vianey Guadalupe; Ochoa Domínguez, Humberto de Jesús; Nandayapa Alfaro, Manuel de Jesús

    2015-02-12

    Lung cancer is a leading cause of death worldwide; it refers to the uncontrolled growth of abnormal cells in the lung. A computed tomography (CT) scan of the thorax is the most sensitive method for detecting cancerous lung nodules. A lung nodule is a round lesion which can be either non-cancerous or cancerous. In the CT, the lung cancer is observed as round white shadow nodules. The possibility to obtain a manually accurate interpretation from CT scans demands a big effort by the radiologist and might be a fatiguing process. Therefore, the design of a computer-aided diagnosis (CADx) system would be helpful as a second opinion tool. The stages of the proposed CADx are: a supervised extraction of the region of interest to eliminate the shape differences among CT images. The Daubechies db1, db2, and db4 wavelet transforms are computed with one and two levels of decomposition. After that, 19 features are computed from each wavelet sub-band. Then, the sub-band and attribute selection is performed. As a result, 11 features are selected and combined in pairs as inputs to the support vector machine (SVM), which is used to distinguish CT images containing cancerous nodules from those not containing nodules. The clinical data set used for experiments consists of 45 CT scans from ELCAP and LIDC. For the training stage 61 CT images were used (36 with cancerous lung nodules and 25 without lung nodules). The system performance was tested with 45 CT scans (23 CT scans with lung nodules and 22 without nodules), different from that used for training. The results obtained show that the methodology successfully classifies cancerous nodules with a diameter from 2 mm to 30 mm. The total preciseness obtained was 82%; the sensitivity was 90.90%, whereas the specificity was 73.91%. The CADx system presented is competitive with other literature systems in terms of sensitivity. The system reduces the complexity of classification by not performing the typical segmentation stage of most CADx

  11. A mixed reality approach for stereo-tomographic quantification of lung nodules.

    Science.gov (United States)

    Chen, Mianyi; Kalra, Mannudeep K; Yun, Wenbing; Cong, Wenxiang; Yang, Qingsong; Nguyen, Terry; Wei, Biao; Wang, Ge

    2016-05-25

    To reduce the radiation dose and the equipment cost associated with lung CT screening, in this paper we propose a mixed reality based nodule measurement method with an active shutter stereo imaging system. Without involving hundreds of projection views and subsequent image reconstruction, we generated two projections of an iteratively placed ellipsoidal volume in the field of view and merging these synthetic projections with two original CT projections. We then demonstrated the feasibility of measuring the position and size of a nodule by observing whether projections of an ellipsoidal volume and the nodule are overlapped from a human observer's visual perception through the active shutter 3D vision glasses. The average errors of measured nodule parameters are less than 1 mm in the simulated experiment with 8 viewers. Hence, it could measure real nodules accurately in the experiments with physically measured projections.

  12. The probability of malignancy in small pulmonary nodules coexisting with potentially operable lung cancer detected by CT

    International Nuclear Information System (INIS)

    Yuan, Yue; Matsumoto, Tsuneo; Hiyama, Atsuto; Miura, Goji; Tanaka, Nobuyuki; Emoto, Takuya; Kawamura, Takeo; Matsunaga, Naofumi

    2003-01-01

    The aim of this study was to assess the probability of malignancy in one or two small nodules 1 cm or less coexisting with potentially operable lung cancer (coexisting small nodules). The preoperative helical CT scans of 223 patients with lung cancer were retrospectively reviewed. The probability of malignancy of coexisting small nodules was evaluated based on nodule size, location, and clinical stage of the primary lung cancers. Seventy-one coexisting small nodules were found on conventional CT in 58 (26%) of 223 patients, and 14 (6%) patients had malignant nodules. Eighteen (25%) of such nodules were malignant. The probability of malignancy was not significantly different between two groups of nodules larger and smaller than 0.5 cm (p=0.1). The probability of malignancy of such nodules within primary tumor lobe was significantly higher than that in the other lobes (p<0.01). Metastatic nodules were significantly fewer in clinical stage-IA patients than in the patients with the other stage (p<0.01); however, four (57%) of seven synchronous lung cancers were located in the non-primary tumor lobes in the clinical stage-I patients. Malignant coexisting small nodules are not infrequent, and such nodules in the non-primary tumor lobes should be carefully diagnosed. (orig.)

  13. Central focused convolutional neural networks: Developing a data-driven model for lung nodule segmentation.

    Science.gov (United States)

    Wang, Shuo; Zhou, Mu; Liu, Zaiyi; Liu, Zhenyu; Gu, Dongsheng; Zang, Yali; Dong, Di; Gevaert, Olivier; Tian, Jie

    2017-08-01

    Accurate lung nodule segmentation from computed tomography (CT) images is of great importance for image-driven lung cancer analysis. However, the heterogeneity of lung nodules and the presence of similar visual characteristics between nodules and their surroundings make it difficult for robust nodule segmentation. In this study, we propose a data-driven model, termed the Central Focused Convolutional Neural Networks (CF-CNN), to segment lung nodules from heterogeneous CT images. Our approach combines two key insights: 1) the proposed model captures a diverse set of nodule-sensitive features from both 3-D and 2-D CT images simultaneously; 2) when classifying an image voxel, the effects of its neighbor voxels can vary according to their spatial locations. We describe this phenomenon by proposing a novel central pooling layer retaining much information on voxel patch center, followed by a multi-scale patch learning strategy. Moreover, we design a weighted sampling to facilitate the model training, where training samples are selected according to their degree of segmentation difficulty. The proposed method has been extensively evaluated on the public LIDC dataset including 893 nodules and an independent dataset with 74 nodules from Guangdong General Hospital (GDGH). We showed that CF-CNN achieved superior segmentation performance with average dice scores of 82.15% and 80.02% for the two datasets respectively. Moreover, we compared our results with the inter-radiologists consistency on LIDC dataset, showing a difference in average dice score of only 1.98%. Copyright © 2017. Published by Elsevier B.V.

  14. Preliminary evaluation of lung care software of 16-slice helical CT in the study of pulmonary nodules

    International Nuclear Information System (INIS)

    Song Wei; Jin Zhengyu; Yan Hongzhen; Wang Yun; Zhang Yunqing; Wang Linhui; Zhu Haifeng; Liang Jixiang; Qi Bing

    2005-01-01

    Objective: To evaluate the auxiliary diagnostic ability and applicability of the Lung Care software for the study of the pulmonary nodules. Methods: Fifty-six patients underwent low-dose CT scan with 1.5 mm collimation, 4 mm reconstruction interval, and 4 mm reconstruction slice in group A, and with 1.5 mm collimation, 2 mm reconstruction interval, and 2 mm reconstruction slice in group B. 12 patients underwent low-dose CT with 0.75 mm collimation, 0.75 mm reconstruction interval, and 0.75 mm reconstruction slice in group C. The nodules detected in groups A, B, and C were analyzed by r-MPR or VOI of the Lung Care software to distinguish the true pulmonary nodules from the vessels. The volume and density distribution of the true pulmonary nodules in groups A, B, and C were measured with the Lung Care software. Results: It was difficult to observe the diffuse pulmonary nodules by r-MPR or VOI of the Lung Care software. The images of each patient in group C were too many to be applied in the clinic. There was statistically consistent in the observation of pulmonary nodules between r-MPR and VOI, but the coincidence was not good (Kappa=0.369, P=0.002). There was statistically significant difference in showing faint nodules between r-MPR and VOI (P=0.001), r-MPR was better than VOI. There was statistically significant difference between group A and B in showing = 3.886, P=0.045), but no statistically significant difference in showing 5-10 mm nodules (χ 2 =0.170, P=0.680). The volume and density distribution of most 5 - ≤20 mm nodules were successfully measured with the Lung Care software, whereas those of most 2 =5.811, P=0.016) and 5-10 mm nodules (χ 2 =13.500, P 10 - ≤20 mm nodules (χ 2 =0.000, P=1.000). Conclusion: For distinguishing the true pulmonary nodules from others, the Lung Care software is suitable for the well-edged pulmonary nodules and most faint nodules, but not suitable for the nodules such as ground-glass opacity. For measuring the volume and

  15. Surveillance of the remaining nodules after resection of the dominant lung adenocarcinoma is an appropriate follow-up strategy

    Directory of Open Access Journals (Sweden)

    Massimo eCastiglioni

    2015-01-01

    Full Text Available IntroductionAdenocarcinomas, commonly present as a dominant lesion (DL with additional nodules in the ipsilateral or contralateral lung. We sought to determine the fate and management of the secondary nodules and to assess the risk of these nodules using the Lung CT Screening Reporting and Data System (Lung-RADS criteria and the National Comprehensive Cancer Network (NCCN guidelines to determine if surveillance is an appropriate strategy.MethodsWe retrospectively evaluated patients with lepidic growth pattern adenocarcinoma and secondary nodules from 2000 to 2013. Risk assessment of the additional lesions was completed with a simplified model of Lung-RADS and NCCN-Guidelines. ResultsEighty-seven patients underwent resection of 87 DLs (Group 1 concurrently with 60 additional pulmonary nodules (Group 2 while 157 non-DLs were radiologically surveyed over a median follow-up time of 3.2 years (Group 3. Malignancy was found in 29/60 (48% nodules in Group 2. Whereas, only 9/157 (6% of the lesions in Group 3 enlarged, 4 of which (2.5% of total were found to be malignant, and then treated, while the remaining nodules continued surveillance. After applying the Lung-RADS and NCCN simplified models, nodules in Group 2 were at higher risk for lung cancer than those in Group 3. ConclusionsIn patients with lepidic growth pattern adenocarcinoma associated with multiple secondary nodules, surveillance of the remaining nodules, after resection of the DL, is a reasonable strategy since these nodules exhibited a slow rate of growth and minimal malignancy. In contrast, nodules resected from the ipsilateral lung at the time of the DL, harbor malignancy in 48%. Risk assessment models may provide a useful and standardized tool for clinical assessment of pulmonary nodules.

  16. Radiomic features analysis in computed tomography images of lung nodule classification.

    Directory of Open Access Journals (Sweden)

    Chia-Hung Chen

    Full Text Available Radiomics, which extract large amount of quantification image features from diagnostic medical images had been widely used for prognostication, treatment response prediction and cancer detection. The treatment options for lung nodules depend on their diagnosis, benign or malignant. Conventionally, lung nodule diagnosis is based on invasive biopsy. Recently, radiomics features, a non-invasive method based on clinical images, have shown high potential in lesion classification, treatment outcome prediction.Lung nodule classification using radiomics based on Computed Tomography (CT image data was investigated and a 4-feature signature was introduced for lung nodule classification. Retrospectively, 72 patients with 75 pulmonary nodules were collected. Radiomics feature extraction was performed on non-enhanced CT images with contours which were delineated by an experienced radiation oncologist.Among the 750 image features in each case, 76 features were found to have significant differences between benign and malignant lesions. A radiomics signature was composed of the best 4 features which included Laws_LSL_min, Laws_SLL_energy, Laws_SSL_skewness and Laws_EEL_uniformity. The accuracy using the signature in benign or malignant classification was 84% with the sensitivity of 92.85% and the specificity of 72.73%.The classification signature based on radiomics features demonstrated very good accuracy and high potential in clinical application.

  17. Aquamous cell carcinomas of the lung which presented as numerous polypoid nodules in the tracheobronchial tree: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Gyu; Choi, Yo Won; Yoon, Hyun Jung; Paik, Seung Sam [Hanyang University Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2017-03-15

    We report a case of squamous cell carcinomas of the lung, which presented as numerous polypoid nodules in the tracheobronchial tree. They occurred at two years and 7 months after resection of squamous cell carcinoma, which presented as a lung nodule in the left lower lobe, and at 7 months after resection of tracheal squamous cell carcinoma.

  18. Aquamous cell carcinomas of the lung which presented as numerous polypoid nodules in the tracheobronchial tree: A case report

    International Nuclear Information System (INIS)

    Lee, Hyun Gyu; Choi, Yo Won; Yoon, Hyun Jung; Paik, Seung Sam

    2017-01-01

    We report a case of squamous cell carcinomas of the lung, which presented as numerous polypoid nodules in the tracheobronchial tree. They occurred at two years and 7 months after resection of squamous cell carcinoma, which presented as a lung nodule in the left lower lobe, and at 7 months after resection of tracheal squamous cell carcinoma

  19. An Unusual Radiologic Manifestation of Pulmonary Tuberculosis with Bilateral Multiple Lung Nodules and Diffuse Alveolar Hemorrhage: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seo In; Seon, Hyun Ju; Kim, Yun Hyeon [Dept. of Radiology, Chunnam National University Hospital, Gwangju (Korea, Republic of); Choi, Sung [Dept. of Radiology, Chunnam National University Hwasun Hospital, Hwasun(Korea, Republic of)

    2011-12-15

    Pulmonary tuberculosis presenting as bilateral multiple lung nodules or diffuse alveolar hemorrhage is very rare. Here, we report a case of pulmonary tuberculosis presenting as bilateral multiple lung nodules and diffuse alveolar hemorrhage mimicking granulomatous vasculitis, such as Wegener's granulomatosis.

  20. Cryptogenic Organizing Pneumonia With Lung Nodules Secondary to Pulmonary Manifestation of Crohn Disease

    Directory of Open Access Journals (Sweden)

    Taufiq Zaman

    2017-05-01

    Full Text Available Crohn disease is an immune-mediated inflammatory condition with gastrointestinal and extraintestinal manifestations in patients. Pulmonary involvement of Crohn disease is one manifestation. There have been case reports which have shown Crohn disease and lung nodules which were noted to be histopathological as cryptogenic organizing pneumonia (COP. In our case, a 22-year-old woman with Crohn disease was seen with complaints of chest pain and cough. Computed tomographic scan of chest showed multiple bilateral lung nodules, for which biopsy was done, which showed COP. The case study is followed by a deeper discussion of COP and the extraintestinal manifestation seen in inflammatory bowel disease.

  1. Lung Nodule Image Classification Based on Local Difference Pattern and Combined Classifier.

    Science.gov (United States)

    Mao, Keming; Deng, Zhuofu

    2016-01-01

    This paper proposes a novel lung nodule classification method for low-dose CT images. The method includes two stages. First, Local Difference Pattern (LDP) is proposed to encode the feature representation, which is extracted by comparing intensity difference along circular regions centered at the lung nodule. Then, the single-center classifier is trained based on LDP. Due to the diversity of feature distribution for different class, the training images are further clustered into multiple cores and the multicenter classifier is constructed. The two classifiers are combined to make the final decision. Experimental results on public dataset show the superior performance of LDP and the combined classifier.

  2. Lung Nodule Image Classification Based on Local Difference Pattern and Combined Classifier

    Directory of Open Access Journals (Sweden)

    Keming Mao

    2016-01-01

    Full Text Available This paper proposes a novel lung nodule classification method for low-dose CT images. The method includes two stages. First, Local Difference Pattern (LDP is proposed to encode the feature representation, which is extracted by comparing intensity difference along circular regions centered at the lung nodule. Then, the single-center classifier is trained based on LDP. Due to the diversity of feature distribution for different class, the training images are further clustered into multiple cores and the multicenter classifier is constructed. The two classifiers are combined to make the final decision. Experimental results on public dataset show the superior performance of LDP and the combined classifier.

  3. Lung nodule detection on chest CT: evaluation of a computer-aided detection (CAD) system

    International Nuclear Information System (INIS)

    Lee, In Jae; Gamsu, Gordon; Czum, Julianna; Johnson, Rebecca; Chakrapani, Sanjay; Wu, Ning

    2005-01-01

    To evaluate the capacity of a computer-aided detection (CAD) system to detect lung nodules in clinical chest CT. A total of 210 consecutive clinical chest CT scans and their reports were reviewed by two chest radiologists and 70 were selected (33 without nodules and 37 with 1-6 nodules, 4-15.4 mm in diameter). The CAD system (ImageChecker CT LN-1000) developed by R2 Technology, Inc. (Sunnyvale, CA) was used. Its algorithm was designed to detect nodules with a diameter of 4-20 mm. The two chest radiologists working with the CAD system detected a total of 78 nodules. These 78 nodules form the database for this study. Four independent observers interpreted the studies with and without the CAD system. The detection rates of the four independent observers without CAD were 81% (63/78), 85% (66/78), 83% (65/78), and 83% (65/78), respectively. With CAD their rates were 87% (68/78), 85% (66/78), 86% (67/78), and 85% (66/78), respectively. The differences between these two sets of detection rates did not reach statistical significance. In addition, CAD detected eight nodules that were not mentioned in the original clinical radiology reports. The CAD system produced 1.56 false-positive nodules per CT study. The four test observers had 0, 0.1, 0.17, and 0.26 false-positive results per study without CAD and 0.07, 0.2, 0.23, and 0.39 with CAD, respectively. The CAD system can assist radiologists in detecting pulmonary nodules in chest CT, but with a potential increase in their false positive rates. Technological improvements to the system could increase the sensitivity and specificity for the detection of pulmonary nodules and reduce these false-positive results

  4. A computerized scheme for lung nodule detection in multiprojection chest radiography

    International Nuclear Information System (INIS)

    Guo Wei; Li Qiang; Boyce, Sarah J.; McAdams, H. Page; Shiraishi, Junji; Doi, Kunio; Samei, Ehsan

    2012-01-01

    Purpose: Our previous study indicated that multiprojection chest radiography could significantly improve radiologists' performance for lung nodule detection in clinical practice. In this study, the authors further verify that multiprojection chest radiography can greatly improve the performance of a computer-aided diagnostic (CAD) scheme. Methods: Our database consisted of 59 subjects, including 43 subjects with 45 nodules and 16 subjects without nodules. The 45 nodules included 7 real and 38 simulated ones. The authors developed a conventional CAD scheme and a new fusion CAD scheme to detect lung nodules. The conventional CAD scheme consisted of four steps for (1) identification of initial nodule candidates inside lungs, (2) nodule candidate segmentation based on dynamic programming, (3) extraction of 33 features from nodule candidates, and (4) false positive reduction using a piecewise linear classifier. The conventional CAD scheme processed each of the three projection images of a subject independently and discarded the correlation information between the three images. The fusion CAD scheme included the four steps in the conventional CAD scheme and two additional steps for (5) registration of all candidates in the three images of a subject, and (6) integration of correlation information between the registered candidates in the three images. The integration step retained all candidates detected at least twice in the three images of a subject and removed those detected only once in the three images as false positives. A leave-one-subject-out testing method was used for evaluation of the performance levels of the two CAD schemes. Results: At the sensitivities of 70%, 65%, and 60%, our conventional CAD scheme reported 14.7, 11.3, and 8.6 false positives per image, respectively, whereas our fusion CAD scheme reported 3.9, 1.9, and 1.2 false positives per image, and 5.5, 2.8, and 1.7 false positives per patient, respectively. The low performance of the conventional

  5. Pulmonary nodules and masses in lung transplant recipients: clinical and CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Morla, Olivier; Liberge, Renan; Arrigoni, Pierre Paul; Frampas, Eric [Service de Radiologie Centrale, C.H.U. Hotel Dieu, Nantes (France)

    2014-09-15

    The purpose of this study was to review the clinical and CT findings of pulmonary nodules and masses in lung transplant recipients and to determine distinguishing features among the various aetiologies. This retrospective study included 106 lung transplant recipients who had a chest CT performed over a 7-year period in a single institution. Twenty-four cases of pulmonary nodules and masses were observed on CT. Among the single lesions, three (50 %) were due to infections, one (17 %) to organizing pneumonia, and two (33 %) remained of undetermined origin. Among the multiple lesions, 14 (78 %) were due to infection, three to post-transplant lymphoproliferative disorder (17 %), and one to bronchogenic carcinoma (5 %). The two main microorganisms were P. aeruginosa and Aspergillus spp. Among 12 solid nodules > 1 cm, four (33 %) were due to malignancy: three post-transplant lymphoproliferative disorders (25 %), and one bronchogenic carcinoma (8 %). Among five cavitary nodules four (80 %) were due to aspergillosis. Infection is the most frequent aetiology of pulmonary nodules and masses in lung transplant recipients, but other causes such as post-transplant lymphoproliferative disorder, bronchogenic carcinoma, or organizing pneumonia should be considered. (orig.)

  6. A Computer-Aided Diagnosis for Evaluating Lung Nodules on Chest CT: the Current Status and Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Jin Mo [Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2011-04-15

    As the detection and characterization of lung nodules are of paramount importance in thoracic radiology, various tools for making a computer-aided diagnosis (CAD) have been developed to improve the diagnostic performance of radiologists in clinical practice. Numerous studies over the years have shown that the CAD system can effectively help readers identify more nodules. Moreover, nodule malignancy and the response of malignant lung tumors to treatment can also be assessed using nodule volumetry. CAD also has the potential to objectively analyze the morphology of nodules and enhance the work flow during the assessment of follow-up studies. Therefore, understanding the current status and limitations of CAD for evaluating lung nodules is essential to effectively apply CAD in clinical practice

  7. Lung nodule detection in pediatric chest CT: quantitative relationship between image quality and radiologist performance.

    Science.gov (United States)

    Li, Xiang; Samei, Ehsan; Barnhart, Huiman X; Gaca, Ana Maria; Hollingsworth, Caroline L; Maxfield, Charles M; Carrico, Caroline W T; Colsher, James G; Frush, Donald P

    2011-05-01

    To determine the quantitative relationship between image quality and radiologist performance in detecting small lung nodules in pediatric CT. The study included clinical chest CT images of 30 pediatric patients (0-16 years) scanned at tube currents of 55-180 mA. Calibrated noise addition software was used to simulate cases at three nominal mA settings: 70, 35, and 17.5 mA, resulting in quantum noise of 7-32 Hounsfield Unit (HU). Using a validated nodule simulation technique, lung nodules with diameters of 3-5 mm and peak contrasts of 200-500 HU were inserted into the cases, which were then randomized and rated independently by four experienced pediatric radiologists for nodule presence on a continuous scale from 0 (definitely absent) to 100 (definitely present). The receiver operating characteristic (ROC) data were analyzed to quantify the relationship between diagnostic accuracy (area under the ROC curve, AUC) and image quality (the product of nodule peak contrast and displayed diameter to noise ratio, CDNR display). AUC increased rapidly from 0.70 to 0.87 when CDNR display increased from 60 to 130 mm, followed by a slow increase to 0.94 when CDNR display further increased to 257 mm. For the average nodule diameter (4 mm) and contrast (350 HU), AUC decreased from 0.93 to 0.71 with noise increased from 7 to 28 HU. We quantified the relationship between image quality and the performance of radiologists in detecting lung nodules in pediatric CT. The relationship can guide CT protocol design to achieve the desired diagnostic performance at the lowest radiation dose.

  8. Malignancy estimation of Lung-RADS criteria for subsolid nodules on CT. Accuracy of low and high risk spectrum when using NLST nodules

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kaman; Jacobs, Colin; Scholten, Ernst T.; Dekker, Irma; Prokop, Mathias; Ginneken, Bram van [Radboud University Medical Centre, Diagnostic Image Analysis Group, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Mets, Onno M. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Schaefer-Prokop, Cornelia M. [Radboud University Medical Centre, Diagnostic Image Analysis Group, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Meander Medical Center, Department of Radiology, Amersfoort (Netherlands)

    2017-11-15

    Lung-RADS proposes malignancy probabilities for categories 2 (<1%) and 4B (>15%). The purpose of this study was to quantify and compare malignancy rates for Lung-RADS 2 and 4B subsolid nodules (SSNs) on a nodule base. We identified all baseline SSNs eligible for Lung-RADS 2 and 4B in the National Lung Screening Trial (NLST) database. Solid cores and nodule locations were annotated using in-house software. Malignant SSNs were identified by an experienced radiologist using NLST information. Malignancy rates and percentages of persistence were calculated. Of the Lung-RADS 2SSNs, 94.3% (1790/1897) could be located on chest CTs. Likewise, 95.1% (331/348) of part-solid nodules ≥6 mm in diameter could be located. Of these, 120 had a solid core ≥8 mm, corresponding to category 4B. Category 2 SSNs showed a malignancy rate of 2.5%, exceeding slightly the proposed rate of <1%. Category 4B SSNs showed a malignancy rate of 23.9%. In both categories one third of benign lesions were transient. Malignancy probabilities for Lung-RADS 2 and 4B generally match malignancy rates in SSNs. An option to include also category 2 SSNs for upgrade to 4X designed for suspicious nodules might be useful in the future. Integration of short-term follow-up to confirm persistence would prevent unnecessary invasive work-up in 4B SSNs. (orig.)

  9. [Cavitating lung lesions in the course of ANCA-associated vasculitis: differential diagnostic aspects].

    Science.gov (United States)

    Kirchner, J; Raab, H P; Länger, F; Wigand, R; Mitrou, P; Jacobi, V

    1998-05-01

    Antineutrophil cytoplasmatic antibodies (ANCA)-associated vasculitides (Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome) show quite variable courses. Clinical features of the full blown generalized systemic vasculitis are usually found in the respiratory tract and the kidney. Pulmonary involvement of Wegener's granulomatosis shows commonly nodules and cavitations but also diffuse alveolar hemorrhage. We report the case of a 57 year-old man suffering from dyspnea, thoracal pain, arthralgia, purpura, scleritis and tinitus. Specimen of the kidney showed segmental glomerulosclerosis and tubulointerstitial nephritis. Because of the presence of cANCA Wegener's disease was assumed. Pulmonary infiltrates developed under immunosuppressive treatment with cyclophosphamid. As differential diagnosis of the pulmonary infiltrates, we considered invasive pulmonary aspergillosis as well as infiltrates due to Wegener's granulomatosis. In spite of maximal therapeutic management of patient died of respiratory and cardiovascular failure. The findings at autopsy showed distinct invasive pulmonary aspergillosis and perifocal hemorrhage.

  10. Outcomes of Stereotactic Body Radiotherapy (SBRT) treatment of multiple synchronous and recurrent lung nodules

    International Nuclear Information System (INIS)

    Owen, Dawn; Olivier, Kenneth R; Mayo, Charles S; Miller, Robert C; Nelson, Kathryn; Bauer, Heather; Brown, Paul D; Park, Sean S; Ma, Daniel J; Garces, Yolanda I

    2015-01-01

    Stereotactic body radiotherapy (SBRT) is evolving into a standard of care for unresectable lung nodules. Local control has been shown to be in excess of 90% at 3 years. However, some patients present with synchronous lung nodules in the ipsilateral or contralateral lobe or metasynchronous disease. In these cases, patients may receive multiple courses of lung SBRT or a single course for synchronous nodules. The toxicity of such treatment is currently unknown. Between 2006 and 2012, 63 subjects with 128 metasynchronous and synchronous lung nodules were treated at the Mayo Clinic with SBRT. Demographic patient data and dosimetric data regarding SBRT treatments were collected. Acute toxicity (defined as toxicity < 90 days) and late toxicity (defined as toxicity > = 90 days) were reported and graded as per standardized CTCAE 4.0 criteria. Local control, progression free survival and overall survival were also described. The median age of patients treated was 73 years. Sixty five percent were primary or recurrent lung cancers with the remainder metastatic lung nodules of varying histologies. Of 63 patients, 18 had prior high dose external beam radiation to the mediastinum or chest. Dose and fractionation varied but the most common prescriptions were 48 Gy/4 fractions, 54 Gy/3 fractions, and 50 Gy/5 fractions. Only 6 patients demonstrated local recurrence. With a median follow up of 12.6 months, median SBRT specific overall survival and progression free survival were 35.7 months and 10.7 months respectively. Fifty one percent (32/63 patients) experienced acute toxicity, predominantly grade 1 and 2 fatigue. One patient developed acute grade 3 radiation pneumonitis at 75 days. Forty six percent (29/63 patients) developed late effects. Most were grade 1 dyspnea. There was one patient with grade 5 pneumonitis. Multiple courses of SBRT and SBRT delivery after external beam radiotherapy appear to be feasible and safe. Most toxicity was grade 1 and 2 but the risk was

  11. Towards automatic pulmonary nodule management in lung cancer screening with deep learning

    NARCIS (Netherlands)

    Ciompi, F.; Chung, K; Riel, S.J. van; Setio, A.A.A.; Gerke, P.K.; Jacobs, C.; Scholten, E.T.; Schaefer-Prokop, C.M.; Wille, M.M.W.; Marchiano, A.; Pastorino, U.; Prokop, M.; Ginneken, B. van

    2017-01-01

    The introduction of lung cancer screening programs will produce an unprecedented amount of chest CT scans in the near future, which radiologists will have to read in order to decide on a patient follow-up strategy. According to the current guidelines, the workup of screen-detected nodules strongly

  12. Investigation of lung nodule detectability in low-dose 320-slice computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, J. D.; Paul, N. S.; Siewerdsen, J. H. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Imaging, Toronto General Hospital, Toronto, Ontario M5G 2C6 (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada) and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

    2009-05-15

    Low-dose imaging protocols in chest CT are important in the screening and surveillance of suspicious and indeterminate lung nodules. Techniques that maintain nodule detectability yet permit dose reduction, particularly for large body habitus, were investigated. The objective of this study was to determine the extent to which radiation dose can be minimized while maintaining diagnostic performance through knowledgeable selection of reconstruction techniques. A 320-slice volumetric CT scanner (Aquilion ONE, Toshiba Medical Systems) was used to scan an anthropomorphic phantom at doses ranging from {approx}0.1 mGy up to that typical of low-dose CT (LDCT, {approx}5 mGy) and diagnostic CT ({approx}10 mGy). Radiation dose was measured via Farmer chamber and MOSFET dosimetry. The phantom presented simulated nodules of varying size and contrast within a heterogeneous background, and chest thickness was varied through addition of tissue-equivalent bolus about the chest. Detectability of a small solid lung nodule (3.2 mm diameter, -37 HU, typically the smallest nodule of clinical significance in screening and surveillance) was evaluated as a function of dose, patient size, reconstruction filter, and slice thickness by means of nine-alternative forced-choice (9AFC) observer tests to quantify nodule detectability. For a given reconstruction filter, nodule detectability decreased sharply below a threshold dose level due to increased image noise, especially for large body size. However, nodule detectability could be maintained at lower doses through knowledgeable selection of (smoother) reconstruction filters. For large body habitus, optimal filter selection reduced the dose required for nodule detection by up to a factor of {approx}3 (from {approx}3.3 mGy for sharp filters to {approx}1.0 mGy for the optimal filter). The results indicate that radiation dose can be reduced below the current low-dose (5 mGy) and ultralow-dose (1 mGy) levels with knowledgeable selection of

  13. Incidental perifissural nodules on routine chest computed tomography. Lung cancer or not?

    Energy Technology Data Exchange (ETDEWEB)

    Mets, Onno M.; Veldhuis, Wouter B.; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Chung, Kaman; Scholten, Ernst T.; Ginneken, Bram van [Radboud University Nijmegen Medical Centre, Diagnostic Image Analysis Group, Nijmegen (Netherlands); Prokop, M. [Radboud University Nijmegen Medical Centre, Department of Radiology, Nijmegen (Netherlands); Schaefer-Prokop, Cornelia M. [Radboud University Nijmegen Medical Centre, Diagnostic Image Analysis Group, Nijmegen (Netherlands); Meander Medical Center, Department of Radiology, Amersfoort (Netherlands)

    2018-03-15

    Perifissural nodules (PFNs) are a common finding on chest CT, and are thought to represent non-malignant lesions. However, data outside a lung cancer-screening setting are currently lacking. In a nested case-control design, out of a total cohort of 16,850 patients ≥ 40 years of age who underwent routine chest CT (2004-2012), 186 eligible subjects with incident lung cancer and 511 controls without were investigated. All non-calcified nodules ≥ 4 mm were semi-automatically annotated. Lung cancer location and subject characteristics were recorded. Cases (56 % male) had a median age of 64 years (IQR 59-70). Controls (60 % male) were slightly younger (p<0.01), median age of 61 years (IQR 51-70). A total of 262/1,278 (21 %) unique non-calcified nodules represented a PFN. None of these were traced to a lung malignancy over a median follow-up of around 4.5 years. PFNs were most often located in the lower lung zones (72 %, p<0.001). Median diameter was 4.6 mm (range: 4.0-8.1), volume 51 mm{sup 3} (range: 32-278). Some showed growth rates < 400 days. Our data show that incidental PFNs do not represent lung cancer in a routine care, heterogeneous population. This confirms prior screening-based results. (orig.)

  14. Application of a kernel-based online learning algorithm to the classification of nodule candidates in computer-aided detection of CT lung nodules

    International Nuclear Information System (INIS)

    Matsumoto, S.; Ohno, Y.; Takenaka, D.; Sugimura, K.; Yamagata, H.

    2007-01-01

    Classification of the nodule candidates in computer-aided detection (CAD) of lung nodules in CT images was addressed by constructing a nonlinear discriminant function using a kernel-based learning algorithm called the kernel recursive least-squares (KRLS) algorithm. Using the nodule candidates derived from the processing by a CAD scheme of 100 CT datasets containing 253 non-calcified nodules or 3 mm or larger as determined by the consensus of two thoracic radiologists, the following trial were carried out 100 times: by randomly selecting 50 datasets for training, a nonlinear discriminant function was obtained using the nodule candidates in the training datasets and tested with the remaining candidates; for comparison, a rule-based classification was tested in a similar manner. At the number of false positives per case of about 5, the nonlinear classification method showed an improved sensitivity of 80% (mean over the 100 trials) compared with 74% of the rule-based method. (orig.)

  15. Application of CT-PSF-based computer-simulated lung nodules for evaluating the accuracy of computer-aided volumetry.

    Science.gov (United States)

    Funaki, Ayumu; Ohkubo, Masaki; Wada, Shinichi; Murao, Kohei; Matsumoto, Toru; Niizuma, Shinji

    2012-07-01

    With the wide dissemination of computed tomography (CT) screening for lung cancer, measuring the nodule volume accurately with computer-aided volumetry software is increasingly important. Many studies for determining the accuracy of volumetry software have been performed using a phantom with artificial nodules. These phantom studies are limited, however, in their ability to reproduce the nodules both accurately and in the variety of sizes and densities required. Therefore, we propose a new approach of using computer-simulated nodules based on the point spread function measured in a CT system. The validity of the proposed method was confirmed by the excellent agreement obtained between computer-simulated nodules and phantom nodules regarding the volume measurements. A practical clinical evaluation of the accuracy of volumetry software was achieved by adding simulated nodules onto clinical lung images, including noise and artifacts. The tested volumetry software was revealed to be accurate within an error of 20 % for nodules >5 mm and with the difference between nodule density and background (lung) (CT value) being 400-600 HU. Such a detailed analysis can provide clinically useful information on the use of volumetry software in CT screening for lung cancer. We concluded that the proposed method is effective for evaluating the performance of computer-aided volumetry software.

  16. Importance of scatter compensation algorithm in heterogeneous tissue for the radiation dose calculation of small lung nodules. A clinical study

    International Nuclear Information System (INIS)

    Baba, Yuji; Murakami, Ryuji; Mizukami, Naohisa; Morishita, Shoji; Yamashita, Yasuyuki; Araki, Fujio; Moribe, Nobuyuki; Hirata, Yukinori

    2004-01-01

    The purpose of this study was to compare radiation doses of small lung nodules calculated with beam scattering compensation and those without compensation in heterogeneous tissues. Computed tomography (CT) data of 34 small (1-2 cm: 12 nodules, 2-3 cm 11 nodules, 3-4 cm 11 nodules) lung nodules were used in the radiation dose measurements. Radiation planning for lung nodule was performed with a commercially available unit using two different radiation dose calculation methods: the superposition method (with scatter compensation in heterogeneous tissues), and the Clarkson method (without scatter compensation in heterogeneous tissues). The energy of the linac photon used in this study was 10 MV and 4 MV. Monitor unit (MU) to deliver 10 Gy at the center of the radiation field (center of the nodule) calculated with the two methods were compared. In 1-2 cm nodules, MU calculated by Clarkson method (MUc) was 90.0±1.1% (4 MV photon) and 80.5±2.7% (10 MV photon) compared to MU calculated by superposion method (MUs), in 2-3 cm nodules, MUc was 92.9±1.1% (4 MV photon) and 86.6±2.8% (10 MV photon) compared to MUs, and in 3-4 cm nodules, MUc was 90.5±2.0% (4 MV photon) and 90.1±1.7% (10 MV photon) compared to MUs. In 1-2 cm nodules, MU calculated without lung compensation (MUn) was 120.6±8.3% (4 MV photon) and 95.1±4.1% (10 MV photon) compared to MU calculated by superposion method (MUs), in 2-3 cm nodules, MUc was 120.3±11.5% (4 MV photon) and 100.5±4.6% (10 MV photon) compared to MUs, and in 3-4 cm nodules, MUc was 105.3±9.0% (4 MV photon) and 103.4±4.9% (10 MV photon) compared to MUs. The MU calculated without lung compensation was not significantly different from the MU calculated by superposition method in 2-3 cm nodules. We found that the conventional dose calculation algorithm without scatter compensation in heterogeneous tissues substantially overestimated the radiation dose of small nodules in the lung field. In the calculation of dose distribution of small

  17. Differential diagnosis and cancer staging of a unique case with multiple nodules in the lung - lung adenocarcinoma, metastasis of colon adenocarcinoma, and colon adenocarcinoma metastasizing to lung adenocarcinoma.

    Science.gov (United States)

    Bai, Yun; Qiu, Jianxing; Shang, Xueqian; Liu, Ping; Zhang, Ying; Wang, Ying; Xiong, Yan; Li, Ting

    2015-05-01

    Lung cancer is the most common cancer in the world. Despite this, there have been few cases of simultaneous primary and metastatic cancers in the lung reported, let alone coexisting with tumor-to-tumor metastasis. Herein, we describe an extremely unusual case. A 61-year-old man with a history of colon adenocarcinoma was revealed as having three nodules in the lung 11 months after colectomy. The nodule in the left upper lobe was primary lung adenocarcinoma, the larger one in the right upper lobe was a metastasis of colon adenocarcinoma, and the smaller one in the right upper lobe was colon adenocarcinoma metastasizing to lung adenocarcinoma. Our paper focused on the differential diagnosis and cancer staging of this unique case, and discussed the uncommon phenomenon of the lung acting as a recipient in tumor-to-tumor metastasis.

  18. Deep-learning derived features for lung nodule classification with limited datasets

    Science.gov (United States)

    Thammasorn, P.; Wu, W.; Pierce, L. A.; Pipavath, S. N.; Lampe, P. D.; Houghton, A. M.; Haynor, D. R.; Chaovalitwongse, W. A.; Kinahan, P. E.

    2018-02-01

    Only a few percent of indeterminate nodules found in lung CT images are cancer. However, enabling earlier diagnosis is important to avoid invasive procedures or long-time surveillance to those benign nodules. We are evaluating a classification framework using radiomics features derived with a machine learning approach from a small data set of indeterminate CT lung nodule images. We used a retrospective analysis of 194 cases with pulmonary nodules in the CT images with or without contrast enhancement from lung cancer screening clinics. The nodules were contoured by a radiologist and texture features of the lesion were calculated. In addition, sematic features describing shape were categorized. We also explored a Multiband network, a feature derivation path that uses a modified convolutional neural network (CNN) with a Triplet Network. This was trained to create discriminative feature representations useful for variable-sized nodule classification. The diagnostic accuracy was evaluated for multiple machine learning algorithms using texture, shape, and CNN features. In the CT contrast-enhanced group, the texture or semantic shape features yielded an overall diagnostic accuracy of 80%. Use of a standard deep learning network in the framework for feature derivation yielded features that substantially underperformed compared to texture and/or semantic features. However, the proposed Multiband approach of feature derivation produced results similar in diagnostic accuracy to the texture and semantic features. While the Multiband feature derivation approach did not outperform the texture and/or semantic features, its equivalent performance indicates promise for future improvements to increase diagnostic accuracy. Importantly, the Multiband approach adapts readily to different size lesions without interpolation, and performed well with relatively small amount of training data.

  19. The computer tomography application of LUNG CARE to detect pulmonary nodules

    International Nuclear Information System (INIS)

    Minnoso Arabi, Yaysel; Ugarte Moreno, Dayana; Jordan Gonzalez, Jose

    2011-01-01

    The pulmonary nodule multiple or unique is frequently a casual finding and it is one of lung's cancer presentation. It's known that cancer is one of the first causes of death in our country and pulmonary tumor has become in a major sanitary problem. Methods. A descriptive prospective was carried out to detect pulmonary nodules in Medical Surgical Research Center. Patients were seen in General Medicine Consultation, in the period of time between January and December 2009. An inquiry was applied to every patients and a computer tomography scan with LUNG CARE program was performed to them. LUNG CARE program is used to early diagnosis and study of pulmonary nodule (mass). The data were analyzed with statistic packet SPSS version 13.0, for Windows. The data were summarized by means of stockings, deviations standard and percent, according to the variable type. For the comparison of the detection of nodules according to technical imagenology the test Chi -square was used at a level of significance of 0,05

  20. Lung nodule detection by microdose CT versus chest radiography (standard and dual-energy subtracted).

    Science.gov (United States)

    Ebner, Lukas; Bütikofer, Yanik; Ott, Daniel; Huber, Adrian; Landau, Julia; Roos, Justus E; Heverhagen, Johannes T; Christe, Andreas

    2015-04-01

    The purpose of this study was to investigate the feasibility of microdose CT using a comparable dose as for conventional chest radiographs in two planes including dual-energy subtraction for lung nodule assessment. We investigated 65 chest phantoms with 141 lung nodules, using an anthropomorphic chest phantom with artificial lung nodules. Microdose CT parameters were 80 kV and 6 mAs, with pitch of 2.2. Iterative reconstruction algorithms and an integrated circuit detector system (Stellar, Siemens Healthcare) were applied for maximum dose reduction. Maximum intensity projections (MIPs) were reconstructed. Chest radiographs were acquired in two projections with bone suppression. Four blinded radiologists interpreted the images in random order. A soft-tissue CT kernel (I30f) delivered better sensitivities in a pilot study than a hard kernel (I70f), with respective mean (SD) sensitivities of 91.1%±2.2% versus 85.6%±5.6% (p=0.041). Nodule size was measured accurately for all kernels. Mean clustered nodule sensitivity with chest radiography was 45.7%±8.1% (with bone suppression, 46.1%±8%; p=0.94); for microdose CT, nodule sensitivity was 83.6%±9% without MIP (with additional MIP, 92.5%±6%; pmicrodose CT for readers 1, 2, 3, and 4 were 84.3%, 90.7%, 68.6%, and 45.0%, respectively. Sensitivities with chest radiography for readers 1, 2, 3, and 4 were 42.9%, 58.6%, 36.4%, and 90.7%, respectively. In the per-phantom analysis, respective sensitivities of microdose CT versus chest radiography were 96.2% and 75% (pmicrodose CT, the applied dose was 0.1323 mSv. Microdose CT is better than the combination of chest radiography and dual-energy subtraction for the detection of solid nodules between 5 and 12 mm at a lower dose level of 0.13 mSv. Soft-tissue kernels allow better sensitivities. These preliminary results indicate that microdose CT has the potential to replace conventional chest radiography for lung nodule detection.

  1. Use of morphologic filters in the computerized detection of lung nodules in digital chest images

    International Nuclear Information System (INIS)

    Yoshimura, H.; Giger, M.L.; Doi, K.; Ahn, N.; MacMahon, H.

    1989-01-01

    The authors have previously described a computerized scheme for the detection of lung nodules based on a difference-image approach, which had a detection accuracy of 70% with 7--8 false positives per image. Currently, they are investigating morphologic filters for the further enhancement/suppression of nodule-signals and the removal of false-positives. Gray-level morphologic filtering is performed on clinical chest radiographs digitized with an optical drum scanner. Various shapes and sequences of erosion and dilation filters (i.e., determination of the minimum and maximum gray levels, respectively) were examined for signal enhancement and suppression for sue in the difference- image approach

  2. Difficulties encountered managing nodules detected during a computed tomography lung cancer screening program.

    Science.gov (United States)

    Veronesi, Giulia; Bellomi, Massimo; Scanagatta, Paolo; Preda, Lorenzo; Rampinelli, Cristiano; Guarize, Juliana; Pelosi, Giuseppe; Maisonneuve, Patrick; Leo, Francesco; Solli, Piergiorgio; Masullo, Michele; Spaggiari, Lorenzo

    2008-09-01

    The main challenge of screening a healthy population with low-dose computed tomography is to balance the excessive use of diagnostic procedures with the risk of delayed cancer detection. We evaluated the pitfalls, difficulties, and sources of mistakes in the management of lung nodules detected in volunteers in the Cosmos single-center screening trial. A total of 5201 asymptomatic high-risk volunteers underwent screening with multidetector low-dose computed tomography. Nodules detected at baseline or new nodules at annual screening received repeat low-dose computed tomography at 1 year if less than 5 mm, repeat low-dose computed tomography 3 to 6 months later if between 5 and 8 mm, and fluorodeoxyglucose positron emission tomography if more than 8 mm. Growing nodules at the annual screening received low-dose computed tomography at 6 months and computed tomography-positron emission tomography or surgical biopsy according to doubling time, type, and size. During the first year of screening, 106 patients underwent lung biopsy and 91 lung cancers were identified (70% were stage I). Diagnosis was delayed (false-negative) in 6 patients (stage IIB in 1 patient, stage IIIA in 3 patients, and stage IV in 2 patients), including 2 small cell cancers and 1 central lesion. Surgical biopsy revealed benign disease (false-positives) in 15 cases (14%). Positron emission tomography sensitivity was 88% for prevalent cancers and 70% for cancers diagnosed after first annual screening. No needle biopsy procedures were performed in this cohort of patients. Low-dose computed tomography screening is effective for the early detection of lung cancers, but nodule management remains a challenge. Computed tomography-positron emission tomography is useful at baseline, but its sensitivity decreases significantly the subsequent year. Multidisciplinary management and experience are crucial for minimizing misdiagnoses.

  3. Systematic Error in Lung Nodule Volumetry : Effect of Iterative Reconstruction Versus Filtered Back Projection at Different CT Parameters

    NARCIS (Netherlands)

    Willemink, Martin J.; Leiner, Tim; Budde, Ricardo P. J.; de Kort, Freek P. L.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Oudkerk, Matthijs; de Jong, Pim A.

    2012-01-01

    OBJECTIVE. Iterative reconstruction potentially can reduce radiation dose compared with filtered back projection (FBP) for chest CT. This is especially important for repeated CT scanning, as is the case in patients with indeterminate lung nodules. It is currently unknown whether absolute nodule

  4. AUTOMATIC LUNG NODULE SEGMENTATION USING AUTOSEED REGION GROWING WITH MORPHOLOGICAL MASKING (ARGMM AND FEATURE EX-TRACTION THROUGH COMPLETE LOCAL BINARY PATTERN AND MICROSCOPIC INFORMATION PATTERN

    Directory of Open Access Journals (Sweden)

    Senthil Kumar

    2015-04-01

    Full Text Available An efficient Autoseed Region Growing with Morphological Masking(ARGMM is imple-mented in this paper on the Lung CT Slice to segment the 'Lung Nodules',which may be the potential indicator for the Lung Cancer. The segmentation of lung nodules car-ried out in this paper through Multi-Thresholding, ARGMM and Level Set Evolution. ARGMM takes twice the time compared to Level Set, but still the number of suspected segmented nodules are doubled, which make sure that no potential cancerous nodules go unnoticed at the earlier stages of diagnosis. It is very important not to panic the patient by finding the presence of nodules from Lung CT scan. Only 40 percent of nod-ules can be cancerous. Hence, in this paper an efficient Shape and Texture analysis is computed to quantitatively describe the segmented lung nodules. The Frequency spectrum of the lung nodules is developed and its frequency domain features are com-puted. The Complete Local binary pattern of lung nodules is computed in this paper by constructing the combine histogram of Sign and Magnitude Local Binary Patterns. Lo-cal Configuration Pattern is also determined in this work for lung nodules to numeri-cally model the microscopic information of nodules pattern.

  5. Potential contribution of multiplanar reconstruction (MPR) to computer-aided detection of lung nodules on MDCT

    International Nuclear Information System (INIS)

    Matsumoto, Sumiaki; Ohno, Yoshiharu; Yamagata, Hitoshi; Nogami, Munenobu; Kono, Atsushi; Sugimura, Kazuro

    2012-01-01

    Purpose: To evaluate potential benefits of using multiplanar reconstruction (MPR) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (MDCT). Materials and methods: MDCT datasets of 60 patients with suspected lung nodules were retrospectively collected. Using “second-read” CAD, two radiologists (Readers 1 and 2) independently interpreted these datasets for the detection of non-calcified nodules (≥4 mm) with concomitant confidence rating. They did this task twice, first without MPR (using only axial images), and then 4 weeks later with MPR (using also coronal and sagittal MPR images), where the total reading time per dataset, including the time taken to assess the detection results of CAD software (CAD assessment time), was recorded. The total reading time and CAD assessment time without MPR and those with MPR were statistically compared for each reader. The radiologists’ performance for detecting nodules without MPR and the performance with MPR were compared using jackknife free-response receiver operating characteristic (JAFROC) analysis. Results: Compared to the CAD assessment time without MPR (mean, 69 s and 57 s for Readers 1 and 2), the CAD assessment time with MPR (mean, 46 s and 45 s for Readers 1 and 2) was significantly reduced (P < 0.001). For Reader 1, the total reading time was also significantly shorter in the case with MPR. There was no significant difference between the detection performances without MPR and with MPR. Conclusion: The use of MPR has the potential to improve the workflow in CAD of lung nodules on MDCT.

  6. AUTOMATIC LUNG NODULE DETECTION BASED ON STATISTICAL REGION MERGING AND SUPPORT VECTOR MACHINES

    Directory of Open Access Journals (Sweden)

    Elaheh Aghabalaei Khordehchi

    2017-06-01

    Full Text Available Lung cancer is one of the most common diseases in the world that can be treated if the lung nodules are detected in their early stages of growth. This study develops a new framework for computer-aided detection of pulmonary nodules thorough a fully-automatic analysis of Computed Tomography (CT images. In the present work, the multi-layer CT data is fed into a pre-processing step that exploits an adaptive diffusion-based smoothing algorithm in which the parameters are automatically tuned using an adaptation technique. After multiple levels of morphological filtering, the Regions of Interest (ROIs are extracted from the smoothed images. The Statistical Region Merging (SRM algorithm is applied to the ROIs in order to segment each layer of the CT data. Extracted segments in consecutive layers are then analyzed in such a way that if they intersect at more than a predefined number of pixels, they are labeled with a similar index. The boundaries of the segments in adjacent layers which have the same indices are then connected together to form three-dimensional objects as the nodule candidates. After extracting four spectral, one morphological, and one textural feature from all candidates, they are finally classified into nodules and non-nodules using the Support Vector Machine (SVM classifier. The proposed framework has been applied to two sets of lung CT images and its performance has been compared to that of nine other competing state-of-the-art methods. The considerable efficiency of the proposed approach has been proved quantitatively and validated by clinical experts as well.

  7. Generation of realistic virtual nodules based on three-dimensional spatial resolution in lung computed tomography: A pilot phantom study.

    Science.gov (United States)

    Narita, Akihiro; Ohkubo, Masaki; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

    2017-10-01

    The aim of this feasibility study using phantoms was to propose a novel method for obtaining computer-generated realistic virtual nodules in lung computed tomography (CT). In the proposed methodology, pulmonary nodule images obtained with a CT scanner are deconvolved with the point spread function (PSF) in the scan plane and slice sensitivity profile (SSP) measured for the scanner; the resultant images are referred to as nodule-like object functions. Next, by convolving the nodule-like object function with the PSF and SSP of another (target) scanner, the virtual nodule can be generated so that it has the characteristics of the spatial resolution of the target scanner. To validate the methodology, the authors applied physical nodules of 5-, 7- and 10-mm-diameter (uniform spheres) included in a commercial CT test phantom. The nodule-like object functions were calculated from the sphere images obtained with two scanners (Scanner A and Scanner B); these functions were referred to as nodule-like object functions A and B, respectively. From these, virtual nodules were generated based on the spatial resolution of another scanner (Scanner C). By investigating the agreement of the virtual nodules generated from the nodule-like object functions A and B, the equivalence of the nodule-like object functions obtained from different scanners could be assessed. In addition, these virtual nodules were compared with the real (true) sphere images obtained with Scanner C. As a practical validation, five types of laboratory-made physical nodules with various complicated shapes and heterogeneous densities, similar to real lesions, were used. The nodule-like object functions were calculated from the images of these laboratory-made nodules obtained with Scanner A. From them, virtual nodules were generated based on the spatial resolution of Scanner C and compared with the real images of laboratory-made nodules obtained with Scanner C. Good agreement of the virtual nodules generated from

  8. Radiological and pathological analysis of LDCT screen detected and surgically resected sub-centimetre lung nodules in 44 asymptomatic patients

    International Nuclear Information System (INIS)

    Hu, Xing; Zhao, Jiangmin; Qian, Haishan; Du, Guangyan; Kelly, Margaret; Yang, Hua

    2016-01-01

    Once lung cancer is detected due to clinical symptoms or by being visible on chest X-ray, it is usually high stage and non-operable. In order to improve mortality rates in lung cancer, low-dose CT (LDCT) screening of “high risk” individuals is gaining popularity. However, the rate of malignancy in LDCT detected sub-centimetre lung nodules is not clear. We aimed to analyze surgically resected specimens in this patient group to explore cost effectiveness and recommendations for clinical management of these nodules. Our hospital pathology database was searched for sub-centimeter lung nodules detected by LDCT screening which were resected. The patient demographics were collected and the radiologic and pathologic characteristics of those nodules were analyzed. From the records, 44 patients with 46 resected subcentimetre nodules were identified. Patients were selected for surgery based on an irregular shape, growth in size during follow up, family history of lung cancer or personal history of cancer of other sites, previous lung disease, smoking and personal anxiety. Of the 44 patients, 33 were women and the ages ranged from 43 to 76 years (56.75 ± 8.44). All nodules were equal to, or less than 10 mm with a mean diameter of 7.81 ± 1.80 mm (SD). Out of 46 nodules, the pathological diagnoses were: invasive adenocarcinoma (ACa) in 4 (8.7%); adenocarcinoma in situ (AIS) or atypical adenomatous hyperplasia (AAH) in 29 (63%); benign fibrosis/fibrotic scar with inflammation or calcification in 12 (26.1%); an intrapulmonary benign lymph node in 1 (2.2%). Of the ACa, AIS and AAH groups (a total of 31 patients), 77% were women (24 vs. 7). The cancer or pre-cancer nodules (ACa, AIS and AAH) tended to be larger than benign fibrotic scars (P = 0.039). Amongst all characteristics, significant statistical differences were found when the following radiological features were considered: reconstructed nodule shape (P = 0.011), margin (P = 0.003) and ground glass pattern (P = 0

  9. Development and validation of a prediction model for measurement variability of lung nodule volumetry in patients with pulmonary metastases.

    Science.gov (United States)

    Hwang, Eui Jin; Goo, Jin Mo; Kim, Jihye; Park, Sang Joon; Ahn, Soyeon; Park, Chang Min; Shin, Yeong-Gil

    2017-08-01

    To develop a prediction model for the variability range of lung nodule volumetry and validate the model in detecting nodule growth. For model development, 50 patients with metastatic nodules were prospectively included. Two consecutive CT scans were performed to assess volumetry for 1,586 nodules. Nodule volume, surface voxel proportion (SVP), attachment proportion (AP) and absolute percentage error (APE) were calculated for each nodule and quantile regression analyses were performed to model the 95% percentile of APE. For validation, 41 patients who underwent metastasectomy were included. After volumetry of resected nodules, sensitivity and specificity for diagnosis of metastatic nodules were compared between two different thresholds of nodule growth determination: uniform 25% volume change threshold and individualized threshold calculated from the model (estimated 95% percentile APE). SVP and AP were included in the final model: Estimated 95% percentile APE = 37.82 · SVP + 48.60 · AP-10.87. In the validation session, the individualized threshold showed significantly higher sensitivity for diagnosis of metastatic nodules than the uniform 25% threshold (75.0% vs. 66.0%, P = 0.004) CONCLUSION: Estimated 95% percentile APE as an individualized threshold of nodule growth showed greater sensitivity in diagnosing metastatic nodules than a global 25% threshold. • The 95 % percentile APE of a particular nodule can be predicted. • Estimated 95 % percentile APE can be utilized as an individualized threshold. • More sensitive diagnosis of metastasis can be made with an individualized threshold. • Tailored nodule management can be provided during nodule growth follow-up.

  10. Automated detection of lung nodules in low-dose computed tomography

    International Nuclear Information System (INIS)

    Cascio, D.; Cheran, S.C.; Chincarini, A.; De Nunzio, G.; Delogu, P.; Fantacci, M.E.; Gargano, G.; Gori, I.; Retico, A.; Masala, G.L.; Preite Martinez, A.; Santoro, M.; Spinelli, C.; Tarantino, T.

    2007-01-01

    A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector computed-tomography (CT) images has been developed in the framework of the MAGIC-5 Italian project. One of the main goals of this project is to build a distributed database of lung CT scans in order to enable automated image analysis through a data and cpu GRID infrastructure. The basic modules of our lung-CAD system, consisting in a 3D dot-enhancement filter for nodule detection and a neural classifier for false-positive finding reduction, are described. The system was designed and tested for both internal and sub-pleural nodules. The database used in this study consists of 17 low-dose CT scans reconstructed with thin slice thickness (∝300 slices/scan). The preliminary results are shown in terms of the FROC analysis reporting a good sensitivity (85% range) for both internal and sub-pleural nodules at an acceptable level of false positive findings (1-9 FP/scan); the sensitivity value remains very high (75% range) even at 1-6 FP/scan. (orig.)

  11. Using YOLO based deep learning network for real time detection and localization of lung nodules from low dose CT scans

    Science.gov (United States)

    Ramachandran S., Sindhu; George, Jose; Skaria, Shibon; V. V., Varun

    2018-02-01

    Lung cancer is the leading cause of cancer related deaths in the world. The survival rate can be improved if the presence of lung nodules are detected early. This has also led to more focus being given to computer aided detection (CAD) and diagnosis of lung nodules. The arbitrariness of shape, size and texture of lung nodules is a challenge to be faced when developing these detection systems. In the proposed work we use convolutional neural networks to learn the features for nodule detection, replacing the traditional method of handcrafting features like geometric shape or texture. Our network uses the DetectNet architecture based on YOLO (You Only Look Once) to detect the nodules in CT scans of lung. In this architecture, object detection is treated as a regression problem with a single convolutional network simultaneously predicting multiple bounding boxes and class probabilities for those boxes. By performing training using chest CT scans from Lung Image Database Consortium (LIDC), NVIDIA DIGITS and Caffe deep learning framework, we show that nodule detection using this single neural network can result in reasonably low false positive rates with high sensitivity and precision.

  12. Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baiyu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Barnhart, Huiman [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina 27705 (United States); Richard, Samuel [Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Robins, Marthony [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Colsher, James [Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Samei, Ehsan [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Department of Biomedical Engineering, and Department of Electronic and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2013-11-15

    Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of

  13. Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR).

    Science.gov (United States)

    Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Robins, Marthony; Colsher, James; Samei, Ehsan

    2013-11-01

    Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables. Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision. Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A. The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of accuracy on reconstruction algorithms

  14. Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

    International Nuclear Information System (INIS)

    Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Robins, Marthony; Colsher, James; Samei, Ehsan

    2013-01-01

    Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of

  15. Volumetry of Artificial Pulmonary Nodules in Ex Vivo Porcine Lungs: Comparison of Semi-automated Volumetry and Radiologists' Performance

    International Nuclear Information System (INIS)

    Jeong, Ju Hyeon; Kim, Jin Hwan; Kim, Song Soo; Jeon, Ho Sang; Lee, Hyun Ju; Park, Noh Hyuck; Cho, Gyu Seong

    2010-01-01

    With the advent of MSCT, the detection rate of small pulmonary nodules is markedly greater. However, there is no definite diagnostic clue to differentiate between malignant and benign nodules, except for the interval growth in small nodule less than 1 cm in diameter. We evaluated the accuracy of computer aided volumetry (CAV) and compared it with 4 radiologists' measurement. Fifteen artificial nodules that were embedded in the ex vivo porcine lung were scanned by MSCT. The diameters and volumes of nodules were independently measured three times, at 5-day intervals, and by four radiologists as well as by CAV. We evaluated the accuracy of the measurements on the basis of the true diameter and volume of the nodules. Using a paired t-test and a Bland-Altman plot, we evaluated whether there was a statistically significant difference between the radiologists' measurements and the CAV. The accuracy of the manual measurements by radiologists revealed a statistically significant difference from the true diameter and volume of the artificial nodules (p 0.01) The results of this study suggest that CAV is an accurate and useful tool to evaluate the volume of pulmonary nodules and can eventually be used to differentiate malignant and benign nodules as well as evaluate the therapeutic response of lung cancer

  16. SPECT/CT of lung nodules using 111In-DOTA-c(RGDfK) in a mouse lung carcinogenesis model.

    Science.gov (United States)

    Hayakawa, Takuya; Mutoh, Michihiro; Imai, Toshio; Tsuta, Koji; Yanaka, Akinori; Fujii, Hirofumi; Yoshimoto, Mitsuyoshi

    2013-08-01

    Lung cancer is one of the leading causes of cancer-related deaths worldwide, including Japan. Although computed tomography (CT) can detect small lung lesions such as those appearing as ground glass opacity, it cannot differentiate between malignant and non-malignant lesions. Previously, we have shown that single photon emission computed tomography (SPECT) imaging using (111)In-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-cyclo-(Arg-Gly-Asp-D-Phe-Lys) (DOTA-c(RGDfK)), an imaging probe of αvβ3 integrin, is useful for the early detection of pancreatic cancer in a hamster pancreatic carcinogenesis model. In this study, we aimed to assess the usefulness of SPECT/CT with (111)In-DOTA-c(RGDfK) for the evaluation of the malignancy of lung cancer. Lung tumors were induced by a single intraperitoneal injection (250 mg/kg) of urethane in male A/J mice. Twenty-six weeks after the urethane treatment, SPECT was performed an hour after injection of (111)In-DOTA-c(RGDfK). Following this, the radioactivity ratios of tumor to normal lung tissue were measured by autoradiography (ARG) in the excised lung samples. We also examined the expression of αvβ3 integrin in mouse and human lung samples. Urethane treatment induced 5 hyperplasias, 41 adenomas and 12 adenocarcinomas in the lungs of 8 A/J mice. SPECT with (111)In-DOTA-c(RGDfK) could clearly visualize lung nodules, though we failed to detect small lung nodules like adenoma and hyperplasias (adenocarcinoma: 66.7%, adenoma: 33.6%, hyperplasia: 0.0%). ARG analysis revealed significant uptake of (111)In-DOTA-c(RGDfK) in all the lesions. Moreover, tumor to normal lung tissue ratios increased along with the progression of carcinogenesis. Histopathological examination using human lung tissue samples revealed clear up-regulation of αvβ3 integrin in well-differentiated adenocarcinoma (Noguchi type B and C) rather than atypical adenomatous hyperplasia. Although there are some limitations in evaluating the malignancy of

  17. Lung contusion and cavitation with exudative plural effusion following extracorporeal shock wave lithotripsy in an adult: a case report

    Directory of Open Access Journals (Sweden)

    Nouri-Majalan Nader

    2010-08-01

    Full Text Available Abstract Introduction Among the complications of extracorporeal shock wave lithotripsy are perinephric bleeding and hypertension. Case presentation We describe the case of a 31-year-old Asian man with an unusual case of hemoptysis and lung contusion and cavitation with exudative plural effusion due to pulmonary trauma following false positioning of extracorporeal shock wave lithotripsy. Differential diagnoses included pneumonia and pulmonary emboli, but these diagnoses were ruled out by the uniformly negative results of a lung perfusion scan, Doppler ultrasound, and culture of bronchoalveolar lavage and plural effusion, and because our patient showed spontaneous improvement. Conclusions False positioning of extracorporeal shock wave lithotripsy can cause lung trauma presenting as pulmonary contusion and cavitation with plural effusion.

  18. Clinical evaluation of a software for automated localization of lung nodules at follow-up CT examinations

    International Nuclear Information System (INIS)

    Beyer, F.; Wormanns, D.; Heindel, W.; Kohl, G.

    2004-01-01

    Purpose: To evaluate a software algorithm for automated localization of pulmonary nodules at follow-up CT examinations of the chest and to determine factors influencing the rate of correctly matched nodules. Materials and Methods: The 'real-time automatic matching' (RAM) algorithm (Siemens LungCare TM software) was applied to 22 follow-up multirow-detector CT (MDCT) examinations in 11 patients (Siemens Somatom VolumeZoom, tube voltage 120 kVp; effective tube current 20 mAs (n=18) or 100 mAs (n=4); 4 x 1 mm detector configuration, 1.25 mm slice thickness; 0.8 mm reconstruction increment; standard lung kernel B50f) with a total of 190 lung nodules (mean diameter 6.7±3.5 mm, range 2-17 mm). The following nodule features were recorded: diameter, edge definition (well- or ill-defined), location (upper, middle or lower third; central or peripheral; right of left lung) and inspiration level (considered identical if the difference of diaphragm-apex distance between baseline and follow-up examination was 2 -test was used to describe influence of nodule features on detection rate. Influence of nodule size was assessed using Mann-Whitney-U-Test. Results: RAM correctly located 164 of 190 of all lung nodules (86.3%). Detection rate did not depend on nodule location (left vs. right lung: p=0.48; upper vs. middle vs. lower third: p=0.96; peripheral vs. central: p=0.47) or diameter (p=0.30). Influence of inspiration level was highly significant (p [de

  19. Variability in CT lung-nodule volumetry: Effects of dose reduction and reconstruction methods.

    Science.gov (United States)

    Young, Stefano; Kim, Hyun J Grace; Ko, Moe Moe; Ko, War War; Flores, Carlos; McNitt-Gray, Michael F

    2015-05-01

    Measuring the size of nodules on chest CT is important for lung cancer staging and measuring therapy response. 3D volumetry has been proposed as a more robust alternative to 1D and 2D sizing methods. There have also been substantial advances in methods to reduce radiation dose in CT. The purpose of this work was to investigate the effect of dose reduction and reconstruction methods on variability in 3D lung-nodule volumetry. Reduced-dose CT scans were simulated by applying a noise-addition tool to the raw (sinogram) data from clinically indicated patient scans acquired on a multidetector-row CT scanner (Definition Flash, Siemens Healthcare). Scans were simulated at 25%, 10%, and 3% of the dose of their clinical protocol (CTDIvol of 20.9 mGy), corresponding to CTDIvol values of 5.2, 2.1, and 0.6 mGy. Simulated reduced-dose data were reconstructed with both conventional filtered backprojection (B45 kernel) and iterative reconstruction methods (SAFIRE: I44 strength 3 and I50 strength 3). Three lab technologist readers contoured "measurable" nodules in 33 patients under each of the different acquisition/reconstruction conditions in a blinded study design. Of the 33 measurable nodules, 17 were used to estimate repeatability with their clinical reference protocol, as well as interdose and inter-reconstruction-method reproducibilities. The authors compared the resulting distributions of proportional differences across dose and reconstruction methods by analyzing their means, standard deviations (SDs), and t-test and F-test results. The clinical-dose repeatability experiment yielded a mean proportional difference of 1.1% and SD of 5.5%. The interdose reproducibility experiments gave mean differences ranging from -5.6% to -1.7% and SDs ranging from 6.3% to 9.9%. The inter-reconstruction-method reproducibility experiments gave mean differences of 2.0% (I44 strength 3) and -0.3% (I50 strength 3), and SDs were identical at 7.3%. For the subset of repeatability cases, inter

  20. Tumor cavitation in patients with stage III non-small-cell lung cancer undergoing concurrent chemoradiotherapy: incidence and outcomes.

    Science.gov (United States)

    Phernambucq, Erik C J; Hartemink, Koen J; Smit, Egbert F; Paul, Marinus A; Postmus, Pieter E; Comans, Emile F I; Senan, Suresh

    2012-08-01

    Commonly reported complications after concurrent chemoradiotherapy (CCRT) in patients with stage III non-small-cell lung cancer (NSCLC) include febrile neutropenia, radiation esophagitis, and pneumonitis. We studied the incidence of tumor cavitation and/or "tumor abscess" after CCRT in a single-institutional cohort. Between 2003 and 2010, 87 patients with stage III NSCLC underwent cisplatin-based CCRT and all subsequent follow-up at the VU University Medical Center. Diagnostic and radiotherapy planning computed tomography scans were reviewed for tumor cavitation, which was defined as a nonbronchial air-containing cavity located within the primary tumor. Pulmonary toxicities scored as Common Toxicity Criteria v3.0 of grade III or more, occurring within 90 days after end of radiotherapy, were analyzed. In the entire cohort, tumor cavitation was observed on computed tomography scans of 16 patients (18%). The histology in cavitated tumors was squamous cell (n = 14), large cell (n = 1), or adenocarcinoma (n = 1). Twenty patients (23%) experienced pulmonary toxicity of grade III or more, other than radiation pneumonitis. Eight patients with a tumor cavitation (seven squamous cell carcinoma) developed severe pulmonary complications; tumor abscess (n = 5), fatal hemorrhage (n = 2), and fatal embolism (n = 1). Two patients with a tumor abscess required open-window thoracostomy post-CCRT. The median overall survival for patients with or without tumor cavitation were 9.9 and 16.3 months, respectively (p = 0.09). With CCRT, acute pulmonary toxicity of grade III or more developed in 50% of patients with stage III NSCLC, who also had radiological features of tumor cavitation. The optimal treatment of patients with this presentation is unclear given the high risk of a tumor abscess.

  1. Automated detection of lung nodules with three-dimensional convolutional neural networks

    Science.gov (United States)

    Pérez, Gustavo; Arbeláez, Pablo

    2017-11-01

    Lung cancer is the cancer type with highest mortality rate worldwide. It has been shown that early detection with computer tomography (CT) scans can reduce deaths caused by this disease. Manual detection of cancer nodules is costly and time-consuming. We present a general framework for the detection of nodules in lung CT images. Our method consists of the pre-processing of a patient's CT with filtering and lung extraction from the entire volume using a previously calculated mask for each patient. From the extracted lungs, we perform a candidate generation stage using morphological operations, followed by the training of a three-dimensional convolutional neural network for feature representation and classification of extracted candidates for false positive reduction. We perform experiments on the publicly available LIDC-IDRI dataset. Our candidate extraction approach is effective to produce precise candidates with a recall of 99.6%. In addition, false positive reduction stage manages to successfully classify candidates and increases precision by a factor of 7.000.

  2. Role of high-resolution CT in the diagnosis of small pulmonary nodules coexisting with potentially operable lung cancer

    International Nuclear Information System (INIS)

    Yuan, Yue; Matsumoto, Tsuneo; Hiyama, Atsuto; Miura, Goji; Tanaka, Nobuyuki; Matsunaga, Naofumi

    2002-01-01

    The purpose of this study was to evaluate whether high-resolution CT (HRCT) could facilitate the preoperative diagnosis of one or two small nodules of 1 cm or less coexisting with a lung cancer, i.e., coexisting small nodule. This study included 27 coexisting small nodules in 24 potentially operable lung cancer patients. An observer study was performed by five radiologists. The observer performances in differentiating malignant from benign coexisting small nodules were evaluated on conventional CT and HRCT using receiver operating characteristic (ROC) analysis. The area under the ROC curve of five observers was 0.731 on HRCT and 0.578 on conventional CT in the differential diagnosis of coexisting small nodules. A significant diagnostic improvement was found on HRCT (p=0.031). This was especially evident for nodules of ground-glass attenuation (p=0.005). HRCT plays an important role in determining the treatment of potentially operable lung cancer patients with coexisting small nodules. (author)

  3. 3D multi-view convolutional neural networks for lung nodule classification

    Science.gov (United States)

    Kang, Guixia; Hou, Beibei; Zhang, Ningbo

    2017-01-01

    The 3D convolutional neural network (CNN) is able to make full use of the spatial 3D context information of lung nodules, and the multi-view strategy has been shown to be useful for improving the performance of 2D CNN in classifying lung nodules. In this paper, we explore the classification of lung nodules using the 3D multi-view convolutional neural networks (MV-CNN) with both chain architecture and directed acyclic graph architecture, including 3D Inception and 3D Inception-ResNet. All networks employ the multi-view-one-network strategy. We conduct a binary classification (benign and malignant) and a ternary classification (benign, primary malignant and metastatic malignant) on Computed Tomography (CT) images from Lung Image Database Consortium and Image Database Resource Initiative database (LIDC-IDRI). All results are obtained via 10-fold cross validation. As regards the MV-CNN with chain architecture, results show that the performance of 3D MV-CNN surpasses that of 2D MV-CNN by a significant margin. Finally, a 3D Inception network achieved an error rate of 4.59% for the binary classification and 7.70% for the ternary classification, both of which represent superior results for the corresponding task. We compare the multi-view-one-network strategy with the one-view-one-network strategy. The results reveal that the multi-view-one-network strategy can achieve a lower error rate than the one-view-one-network strategy. PMID:29145492

  4. Differentiating early malignant lung tumors from inflammatory nodules to minimize the use of video-assisted thoracoscopic surgery or open biopsy to establish a diagnosis

    International Nuclear Information System (INIS)

    Nomori, Hiroaki; Horio, Hirotoshi; Suemasu, Keiichi

    2001-01-01

    To decrease the frequency of video-assisted thoracoscopic surgery (VATS) biopsy being used to diagnose inflammatory nodules, we studied the clinicopathological findings of lung cancers and inflammatory nodules diagnosed by VATS or open-lung biopsy. We studied 46 lung cancers and 47 inflammatory nodules smaller than 30 mm in diameter diagnosed by VATS or open-lung biopsy. While the computed tomography (CT) findings were not significantly different between lung cancers and inflammatory nodules, N1 or N2 lung cancers more frequently showed distinct malignant features on CT than T1N0M0 lung cancers (P<0.05). A review of previous chest X-ray films revealed that those of inflammatory nodules showed new nodules more frequently and nodular enlargement less frequently than those of lung cancer (P<0.01). Of 13 lung cancers that showed nodular enlargement during a mean 15-month period, 12 were T1N0M0. Nondiagnosable small lung nodules, which had few malignant features on CT and had newly appeared on a chest X-ray film, were more likely to be inflammatory nodules than lung cancers; and even if they were lung cancers, the tumor stage was usually T1N0M0. Thus, to decrease the incidence of VATS biopsy being performed for inflammatory nodules, intensive follow-up by CT until slight nodular enlargement becomes evident could be a means of revealing nondiagnosable small lung nodules without distinct malignant findings, except for nodules found to be enlarging on a review of retrospective films. (author)

  5. Lung nodule assessment in computed tomography. Precision of attenuation measurement based on computer-aided volumetry

    International Nuclear Information System (INIS)

    Knoess, Naomi; Hoffmann, B.; Fabel, M.; Wiese, C.; Bolte, H.; Heller, M.; Biederer, J.; Jochens, A.

    2009-01-01

    Purpose: to compare the reproducibility (r) of CT value measurement of pulmonary nodules using volumetry software (LungCare, LC) and manual ROIs (mROI). Materials and methods: 54 artificial nodules in a chest phantom were scanned three times with CT. CT values were measured with LC and mROI. The intrascan-r was assessed with three measurements in the first scan, and the interscan-r with measurements in three consecutive scans (one observer). Intrascan-r und interobserver-r (two obs.) were assessed in the first scan and in contrast-enhanced CT of 51 nodules from 15 patients (kernels b50f and b80f). Intrascan-r and interscan-r were described as the mean range and interobserver-r as the mean difference of CT values. The significance of differences was tested using t-test and sign test. Results: reproducibility was significantly higher for volumetry-based measurements in both artificial and patient nodules (range 0.11 vs. 6.16 HU for intrascan-r, 2.22 vs. 7.03 HU for interscan-r, difference 0.11 vs. 18.42 HU for interobserver-r; patients: 1.78 vs. 13.19 HU (b50f-Kernel) and 1.88 vs. 27.4 HU (b80f-Kernel) for intrascan-r, 3.71 vs. 22.43 HU for interobserver-r). Absolute CT values differed significantly between convolution kernels (pat./mROI: 29.3 [b50f] and 151.9 HU [b80f] pat./LC: 5 [b50f] and 147 HU [b80f]). Conclusion: the reproducibility of volumetry-based measurements of CT values in pulmonary nodules is significantly higher and should therefore be recommended, e.g. in dynamic chest CT protocols. Reproducibility does not depend on absolute CT values. (orig.)

  6. Computer-aided classification of lung nodules on computed tomography images via deep learning technique

    Directory of Open Access Journals (Sweden)

    Hua KL

    2015-08-01

    Full Text Available Kai-Lung Hua,1 Che-Hao Hsu,1 Shintami Chusnul Hidayati,1 Wen-Huang Cheng,2 Yu-Jen Chen3 1Department of Computer Science and Information Engineering, National Taiwan University of Science and Technology, 2Research Center for Information Technology Innovation, Academia Sinica, 3Department of Radiation Oncology, MacKay Memorial Hospital, Taipei, Taiwan Abstract: Lung cancer has a poor prognosis when not diagnosed early and unresectable lesions are present. The management of small lung nodules noted on computed tomography scan is controversial due to uncertain tumor characteristics. A conventional computer-aided diagnosis (CAD scheme requires several image processing and pattern recognition steps to accomplish a quantitative tumor differentiation result. In such an ad hoc image analysis pipeline, every step depends heavily on the performance of the previous step. Accordingly, tuning of classification performance in a conventional CAD scheme is very complicated and arduous. Deep learning techniques, on the other hand, have the intrinsic advantage of an automatic exploitation feature and tuning of performance in a seamless fashion. In this study, we attempted to simplify the image analysis pipeline of conventional CAD with deep learning techniques. Specifically, we introduced models of a deep belief network and a convolutional neural network in the context of nodule classification in computed tomography images. Two baseline methods with feature computing steps were implemented for comparison. The experimental results suggest that deep learning methods could achieve better discriminative results and hold promise in the CAD application domain. Keywords: nodule classification, deep learning, deep belief network, convolutional neural network

  7. Data-Driven Decision Support for Radiologists: Re-using the National Lung Screening Trial Dataset for Pulmonary Nodule Management

    OpenAIRE

    Morrison, James J.; Hostetter, Jason; Wang, Kenneth; Siegel, Eliot L.

    2014-01-01

    Real-time mining of large research trial datasets enables development of case-based clinical decision support tools. Several applicable research datasets exist including the National Lung Screening Trial (NLST), a dataset unparalleled in size and scope for studying population-based lung cancer screening. Using these data, a clinical decision support tool was developed which matches patient demographics and lung nodule characteristics to a cohort of similar patients. The NLST dataset was conve...

  8. 68Ga-DOTATATE PET/CT imaging of indeterminate pulmonary nodules and lung cancer.

    Directory of Open Access Journals (Sweden)

    Ronald Walker

    Full Text Available 18F-FDG PET/CT is widely used to evaluate indeterminate pulmonary nodules (IPNs. False positive results occur, especially from active granulomatous nodules. A PET-based imaging agent with superior specificity to 18F-FDG for IPNs, is badly needed, especially in areas of endemic granulomatous nodules. Somatostatin receptors (SSTR are expressed in many malignant cells including small cell and non-small cell lung cancers (NSCLCs. 68Ga-DOTATATE, a positron emitter labeled somatostatin analog, combined with PET/CT imaging, may improve the diagnosis of IPNs over 18F-FDG by reducing false positives. Our study purpose was to test this hypothesis in our region with high endemic granulomatous IPNs.We prospectively performed 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT scans in the same 30 patients with newly diagnosed, treatment-naïve lung cancer (N = 14 or IPNs (N = 15 and one metastatic nodule. 68Ga-DOTATATE SUVmax levels at or above 1.5 were considered likely malignant. We analyzed the scan results, correlating with ultimate diagnosis via biopsy or 2-year chest CT follow-up. We also correlated 68Ga-DOTATATE uptake with immunohistochemical (IHC staining for SSTR subtype 2A (SSTR2A in pathological specimens.We analyzed 31 lesions in 30 individuals, with 14 (45% being non-neuroendocrine lung cancers and 1 (3% being metastatic disease. McNemar's result comparing the two radiopharmaceuticals (p = 0.65 indicates that their accuracy of diagnosis in this indication are equivalent. 68Ga-DOTATATE was more specific (94% compared to 81% and less sensitive 73% compared to 93% than 18F-FDG. 68Ga-DOTATATE uptake correlated with SSTR2A expression in tumor stroma determined by immunohistochemical (IHC staining in 5 of 9 (55% NSCLCs.68Ga-DOTATATE and 18F-FDG PET/CT had equivalent accuracy in the diagnosis of non-neuroendocrine lung cancer and 68Ga-DOTATATE was more specific than 18F-FDG for the diagnosis of IPNs. IHC staining for SSTR2A receptor expression correlated with

  9. The use of abatacept in debilitating cavitating lung disease associated with rheumatoid arthritis, bronchocentric granulomatosis and aspergillosis.

    LENUS (Irish Health Repository)

    Neff, K

    2010-06-01

    A case of debilitating cavitating lung disease associated with rheumatoid arthritis and bronchocentric granulomatosis, which failed to respond to conventional medical or surgical treatment, is described. The patient was treated over 10 years with steroids, antimicrobial agents, disease-modifying antirheumatoid drugs and surgery. Lung function continued to decline and the patient presented for admission with recurrent pneumonia. Abatacept was initiated to modify the underlying immunopathology. Following 12 months of treatment with abatacept the patient has demonstrable improvement in lung function and lung anatomy, and has not presented to hospital with pneumonia. She has tolerated the treatment without complication. The use of abatacept has stabilised the lung disease in this case in the medium term and prevented readmission to hospital. These results suggest a larger role for abatacept in those with such disease in the future and may warrant further investigation.

  10. Soft computing approach to 3D lung nodule segmentation in CT.

    Science.gov (United States)

    Badura, P; Pietka, E

    2014-10-01

    This paper presents a novel, multilevel approach to the segmentation of various types of pulmonary nodules in computed tomography studies. It is based on two branches of computational intelligence: the fuzzy connectedness (FC) and the evolutionary computation. First, the image and auxiliary data are prepared for the 3D FC analysis during the first stage of an algorithm - the masks generation. Its main goal is to process some specific types of nodules connected to the pleura or vessels. It consists of some basic image processing operations as well as dedicated routines for the specific cases of nodules. The evolutionary computation is performed on the image and seed points in order to shorten the FC analysis and improve its accuracy. After the FC application, the remaining vessels are removed during the postprocessing stage. The method has been validated using the first dataset of studies acquired and described by the Lung Image Database Consortium (LIDC) and by its latest release - the LIDC-IDRI (Image Database Resource Initiative) database. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Diagnostic feasibility and safety of CT-guided core biopsy for lung nodules less than or equal to 8 mm. A single-institution experience

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ying-Yueh [Taipei Veterans General Hospital, Department of Radiology, Taipei (China); Chen, Chun-Ku [Taipei Veterans General Hospital, Department of Radiology, Taipei (China); National Yang-Ming University, School of Medicine, Taipei (China); National Yang-Ming University, Institute of Clinical Medicine, Taipei (China); Yeh, Yi-Chen [National Yang-Ming University, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Department of Pathology and Laboratory Medicine, Taipei (China); Wu, Mei-Han [Taipei Veterans General Hospital, Department of Radiology, Taipei (China); National Yang-Ming University, School of Medicine, Taipei (China)

    2018-02-15

    This retrospective study evaluated the diagnostic yield and safety of CT-guided core biopsy of pulmonary nodules ≤8 mm. We determined the diagnostic yield and safety profile of CT-guided lung biopsies for 125 pulmonary nodules ≤8 mm. Pathological diagnoses were made by a combination of histopathological examination and imprint cytology. Results were compared with biopsy results for 134 pulmonary nodules >8 and ≤10 mm. Final diagnoses were established in 94 nodules ≤8 mm. The sensitivity, specificity and diagnostic accuracy of CT-guided core biopsy for nodules ≤8 mm were 87.1 % (61/70 nodules), 100 % (24/24) and 90.4 % (85/94), respectively. Diagnostic failure rates were comparable for nodules ≤8 mm and nodules >8 mm and ≤10 mm (9/94, 9.6 % and 7/111, 6.3 %, respectively, P=0.385). The rate of tube thoracostomy for nodules ≤8 mm was comparable to that for nodules >8 and ≤10 mm (1.6 % vs. 0.7 %, P=0.611). Nodules ≤6 mm had a higher non-diagnostic result rate of 15.4 % (6/39) than did nodules >8 and ≤10 mm (3.7 %, 5/134, P=0.017). CT-guided pulmonary biopsy is feasible for lung nodules ≤8 mm, especially those >6 mm, and has an acceptable diagnostic yield and safety profile. (orig.)

  12. Improvement in visibility of simulated lung nodules on computed radiography (CR) chest images by use of temporal subtraction technique

    International Nuclear Information System (INIS)

    Oda, Nobuhiro; Fujimoto, Keiji; Murakami, Seiichi; Katsuragawa, Shigehiko; Doi, Kunio; Nakata, Hajime

    1999-01-01

    A temporal subtraction image obtained by subtraction of a previous image from a current one can enhance interval change on chest images. In this study, we compared the visibility of simulated lung nodules on CR images with and without temporal subtraction. Chest phantom images without and with simulated nodules were obtained as previous and current images, respectively, by a CR system. Then, subtraction images were produced with an iterative image warping technique. Twelve simulated nodules were attached on various locations of the chest phantom. The diameter of nodules having a CT number of 47 ranged from 3 mm to 10 mm. Seven radiologists subjectively evaluated the visibility of simulated nodules on CR images with and without temporal subtraction using a three-point rating scale (0: invisible, +1: questionable, +2:visible). The minimum diameter of simulated nodules visible at a frequency greater than 50% was 4 mm on the CR images with temporal subtraction and 6 mm on those without. Our results indicated that the subtraction images clearly improved the visibility of simulated nodules. (author)

  13. Dynamic Gd-DTPA enhanced breath-hold 1.5 t MRI of normal lungs and patients with interstitial lung disease and pulmonary nodules: preliminary results

    International Nuclear Information System (INIS)

    Semelka, R.C.; Maycher, B.; Shoenut, J.P.; Kroeker, R.; Griffin, P.; Lertzman, M.

    1992-01-01

    A FLASH technique was used, which encompassed the entire thorax in the transverse plane, before and after dynamic intravenous injection of godalinium DTPA (Gd-DTPA) to study 7 patients with normal lungs, 12 patients with interstitial lung disease (ILD), and 11 patients with pulmonary nodules. Comparative CT studies were obtained within 2 weeks of the MRI study in the patients with lung disease. Quantitative signal intensity (SI) measurements were performed. Qualitative evaluation of lung parenchyma was determined in a prospective blinded fashion, and in the normal group comparison was made with the CT images. In normal patients, SI of lung parenchyma increased by 7.7±1.3%. On precontrast images, second-order pulmonary branchings were visible while post-contrast, fifth- to sixth-order branches were apparent. In patients with ILD, interstitial changes enhanced to a variable extent, increases in SI ranging from minimal (49.9%) to substantial (308.4%). Detection of pulmonary nodules improved following contrast injection. The minimum lesion size detectable decreased from 8 mm precontrast to 5 mm post-contrast. Percentage contrast enhancement was greater for malignant nodules (124.2±79.7%) than benign nodules (5.8±4.7%) (p<0.01). (orig.)

  14. Computer-aided detection of lung nodules on chest CT: issues to be solved before clinical use

    International Nuclear Information System (INIS)

    Goo, Jin Mo

    2005-01-01

    Given the increasing resolution of modern CT scanners, and the requirements for large-scale lung-screening examinations and diagnostic studies, there is an increased need for the accurate and reproducible analysis of the large number of images. Nodule detection is one of the main challenges of CT imaging, as they can be missed due to their small size, low relative contrast, or because they are located in an area with complex anatomy. Recent developments in computer-aided diagnosis (CAD) schemes are expected to aid radiologists in various tasks of chest imaging. In this era of multidetector row CT, the thoracic applications of greatest interest include the detection and volume measurement of lung nodules (1-7). Technology for CAD as applied to lung nodule detection on chest CT has been approved by the Food and Drug Administration and is currently commercially available. The article by Lee et al. (5) in this issue of the Korean Journal of Radiology is one of the few studies to examine the influence of a commercially available CAD system on the detection of lung nodules. In this study, some additional nodules were detected with the help of a CAD system, but at the expense of increased false positivity. The nodule detection rate of the CAD system in this study was lower than that achieved by radiologist, and the authors insist that the CAD system should be improved further. Compared to the use of CAD on mammograms, CAD evaluations of chest CTs remain limited to the laboratory setting. In this field, apart from the issues of detection rate and false positive detections, many obstacles must be overcome before CAD can be used in a true clinical reading environment. In this editorial, I will list some of these issues, but I emphasize now that I believe these issues will be solved by improved CAD versions in the near future

  15. Computer-aided detection of lung nodules via 3D fast radial transform, scale space representation, and Zernike MIP classification.

    Science.gov (United States)

    Riccardi, Alessandro; Petkov, Todor Sergueev; Ferri, Gianluca; Masotti, Matteo; Campanini, Renato

    2011-04-01

    The authors presented a novel system for automated nodule detection in lung CT exams. The approach is based on (1) a lung tissue segmentation preprocessing step, composed of histogram thresholding, seeded region growing, and mathematical morphology; (2) a filtering step, whose aim is the preliminary detection of candidate nodules (via 3D fast radial filtering) and estimation of their geometrical features (via scale space analysis); and (3) a false positive reduction (FPR) step, comprising a heuristic FPR, which applies thresholds based on geometrical features, and a supervised FPR, which is based on support vector machines classification, which in turn, is enhanced by a feature extraction algorithm based on maximum intensity projection processing and Zernike moments. The system was validated on 154 chest axial CT exams provided by the lung image database consortium public database. The authors obtained correct detection of 71% of nodules marked by all radiologists, with a false positive rate of 6.5 false positives per patient (FP/patient). A higher specificity of 2.5 FP/patient was reached with a sensitivity of 60%. An independent test on the ANODE09 competition database obtained an overall score of 0.310. The system shows a novel approach to the problem of lung nodule detection in CT scans: It relies on filtering techniques, image transforms, and descriptors rather than region growing and nodule segmentation, and the results are comparable to those of other recent systems in literature and show little dependency on the different types of nodules, which is a good sign of robustness.

  16. Toxocariasis masquerading as liver and lung metastatic nodules in patents with gastrointestinal cancer: clinicopathologic study of five cases.

    Science.gov (United States)

    Park, Sanghui; Kim, Yun Soo; Kim, Yu Jin; Kyung, Sun Young; Park, Jeong-Woong; Jeong, Sung Hwan; Lee, Sang Pyo

    2012-01-01

    There are sporadic reports in the literature in which radiologic liver and lung lesions found incidentally during follow-up metastatic surveillance were shown to be caused by toxocariasis. The objective of the work discussed in this report was to identify common clinical and histopathological features of toxocariasis resembling metastatic nodules in five patients with gastrointestinal cancer. We retrospectively analyzed clinical features of five gastrointestinal cancer patients with liver or lung nodules mimicking metastasis. Serologic tests for parasitic infestations and pathologic examinations were performed. All five patients were males and three patients had gastric cancer and two had colorectal cancer. All the cases of toxocariasis were confirmed serologically. On follow-up imaging, the lesions improved or resolved, suggestive of the phenomenon of visceral larva migrans. In two patients, liver biopsy was performed and showed eosinophilic abscess. Serologic tests and liver or lung biopsy should be performed aggressively to exclude toxocariasis when patients with underlying gastrointestinal cancer present with hepatic or pulmonary nodules associated with eosinophilia, particularly if the patients have a clinical history of raw animal liver ingestion. Curative surgical intervention should not be excluded just because of multiple nodules in the liver or the lungs.

  17. Sublobar resection is equivalent to lobectomy for clinical stage 1A lung cancer in solid nodules.

    Science.gov (United States)

    Altorki, Nasser K; Yip, Rowena; Hanaoka, Takaomi; Bauer, Thomas; Aye, Ralph; Kohman, Leslie; Sheppard, Barry; Thurer, Richard; Andaz, Shahriyour; Smith, Michael; Mayfield, William; Grannis, Fred; Korst, Robert; Pass, Harvey; Straznicka, Michaela; Flores, Raja; Henschke, Claudia I

    2014-02-01

    A single randomized trial established lobectomy as the standard of care for the surgical treatment of early-stage non-small cell lung cancer. Recent advances in imaging/staging modalities and detection of smaller tumors have once again rekindled interest in sublobar resection for early-stage disease. The objective of this study was to compare lung cancer survival in patients with non-small cell lung cancer with a diameter of 30 mm or less with clinical stage 1 disease who underwent lobectomy or sublobar resection. We identified 347 patients diagnosed with lung cancer who underwent lobectomy (n = 294) or sublobar resection (n = 53) for non-small cell lung cancer manifesting as a solid nodule in the International Early Lung Cancer Action Program from 1993 to 2011. Differences in the distribution of the presurgical covariates between sublobar resection and lobectomy were assessed using unadjusted P values determined by logistic regression analysis. Propensity scoring was performed using the same covariates. Differences in the distribution of the same covariates between sublobar resection and lobectomy were assessed using adjusted P values determined by logistic regression analysis with adjustment for the propensity scores. Lung cancer-specific survival was determined by the Kaplan-Meier method. Cox survival regression analysis was used to compare sublobar resection with lobectomy, adjusted for the propensity scores, surgical, and pathology findings, when adjusted and stratified by propensity quintiles. Among 347 patients, 10-year Kaplan-Meier for 53 patients treated by sublobar resection compared with 294 patients treated by lobectomy was 85% (95% confidence interval, 80-91) versus 86% (confidence interval, 75-96) (P = .86). Cox survival analysis showed no significant difference between sublobar resection and lobectomy when adjusted for propensity scores or when using propensity quintiles (P = .62 and P = .79, respectively). For those with cancers 20 mm or less in

  18. Roles of computed tomography and [18F]fluorodeoxyglucose-positron emission tomography/computed tomography in the characterization of multiple solitary solid lung nodules

    OpenAIRE

    Travaini, LL; Trifirò, G; Vigna, PD; Veronesi, G; De Pas, TM; Spaggiari, L; Paganelli, G; Bellomi, M

    2012-01-01

    The purpose of this study is to compare the performance of multidetector computed tomography (CT) and positron emission tomography/CT (PET/CT) with [18F]fluorodeoxyglucose in the diagnosis of multiple solitary lung nodules in 14 consecutive patients with suspicious lung cancer. CT and PET/CT findings were reviewed by a radiologist and nuclear medicine physician, respectively, blinded to the pathological diagnoses of lung cancer, considering nodule size, shape, and location (CT) and maximum st...

  19. Comparison of image features calculated in different dimensions for computer-aided diagnosis of lung nodules

    Science.gov (United States)

    Xu, Ye; Lee, Michael C.; Boroczky, Lilla; Cann, Aaron D.; Borczuk, Alain C.; Kawut, Steven M.; Powell, Charles A.

    2009-02-01

    Features calculated from different dimensions of images capture quantitative information of the lung nodules through one or multiple image slices. Previously published computer-aided diagnosis (CADx) systems have used either twodimensional (2D) or three-dimensional (3D) features, though there has been little systematic analysis of the relevance of the different dimensions and of the impact of combining different dimensions. The aim of this study is to determine the importance of combining features calculated in different dimensions. We have performed CADx experiments on 125 pulmonary nodules imaged using multi-detector row CT (MDCT). The CADx system computed 192 2D, 2.5D, and 3D image features of the lesions. Leave-one-out experiments were performed using five different combinations of features from different dimensions: 2D, 3D, 2.5D, 2D+3D, and 2D+3D+2.5D. The experiments were performed ten times for each group. Accuracy, sensitivity and specificity were used to evaluate the performance. Wilcoxon signed-rank tests were applied to compare the classification results from these five different combinations of features. Our results showed that 3D image features generate the best result compared with other combinations of features. This suggests one approach to potentially reducing the dimensionality of the CADx data space and the computational complexity of the system while maintaining diagnostic accuracy.

  20. The MAGIC-5 CAD for nodule detection in low dose and thin slice lung CTs

    International Nuclear Information System (INIS)

    Cerello, Piergiorgio

    2010-01-01

    Lung cancer is the leading cause of cancer-related mortality in developed countries. Only 10-15% of all men and women diagnosed with lung cancer live 5 years after the diagnosis. However, the 5-year survival rate for patients diagnosed in the early asymptomatic stage of the disease can reach 70%. Early-stage lung cancers can be diagnosed by detecting non-calcified small pulmonary nodules with computed tomography (CT). Computer-aided detection (CAD) could support radiologists in the analysis of the large amount of noisy images generated in screening programs, where low-dose and thin-slice settings are used. The MAGIC-5 project, funded by the Istituto Nazionale di Fisica Nucleare (INFN, Italy) and Ministero dell'Universita e della Ricerca (MUR, Italy), developed a multi-method approach based on three CAD algorithms to be used in parallel with a merging of their results: the Channeler Ant Model (CAM), based on Virtual Ant Colonies, the Dot-Enhancement/Pleura Surface Normals/VBNA (DE-PSN-VBNA), and the Region Growing Volume Plateau (RGVP). Preliminary results show quite good performances, to be improved with the refining of the single algorithm and the added value of the results merging.

  1. Clinical, pathological, and radiological characteristics of solitary ground-glass opacity lung nodules on high-resolution computed tomography

    Directory of Open Access Journals (Sweden)

    Qiu ZX

    2016-09-01

    Full Text Available Zhi-Xin Qiu,1 Yue Cheng,1 Dan Liu,1 Wei-Ya Wang,2 Xia Wu,2 Wei-Lu Wu,2 Wei-Min Li1,2 1Department of Respiratory Medicine, 2Department of Pathology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Background: Lung nodules are being detected at an increasing rate year by year with high-resolution computed tomography (HRCT being widely used. Ground-glass opacity nodule is one of the special types of pulmonary nodules that is confirmed to be closely associated with early stage of lung cancer. Very little is known about solitary ground-glass opacity nodules (SGGNs. In this study, we analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT.Methods: A total of 95 resected SGGNs were evaluated with HRCT scan. The clinical, pathological, and radiological characteristics of these cases were analyzed.Results: Eighty-one adenocarcinoma and 14 benign nodules were observed. The nodules included 12 (15% adenocarcinoma in situ (AIS, 14 (17% minimally invasive adenocarcinoma (MIA, and 55 (68% invasive adenocarcinoma (IA. No patients with recurrence till date have been identified. The positive expression rates of anaplastic lymphoma kinase and ROS-1 (proto-oncogene tyrosine-protein kinase ROS were only 2.5% and 8.6%, respectively. The specificity and accuracy of HRCT of invasive lung adenocarcinoma were 85.2% and 87.4%. The standard uptake values of only two patients determined by 18F-FDG positron emission tomography/computed tomography (PET/CT were above 2.5. The size, density, shape, and pleural tag of nodules were significant factors that differentiated IA from AIS and MIA. Moreover, the size, shape, margin, pleural tag, vascular cluster, bubble-like sign, and air bronchogram of nodules were significant determinants for mixed ground-glass opacity nodules (all P<0.05.Conclusion: We analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT and found that the size, density

  2. Techniques for virtual lung nodule insertion: volumetric and morphometric comparison of projection-based and image-based methods for quantitative CT

    Science.gov (United States)

    Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Sedlmair, Martin; Choudhury, Kingshuk Roy; Pezeshk, Aria; Sahiner, Berkman; Samei, Ehsan

    2017-09-01

    Virtual nodule insertion paves the way towards the development of standardized databases of hybrid CT images with known lesions. The purpose of this study was to assess three methods (an established and two newly developed techniques) for inserting virtual lung nodules into CT images. Assessment was done by comparing virtual nodule volume and shape to the CT-derived volume and shape of synthetic nodules. 24 synthetic nodules (three sizes, four morphologies, two repeats) were physically inserted into the lung cavity of an anthropomorphic chest phantom (KYOTO KAGAKU). The phantom was imaged with and without nodules on a commercial CT scanner (SOMATOM Definition Flash, Siemens) using a standard thoracic CT protocol at two dose levels (1.4 and 22 mGy CTDIvol). Raw projection data were saved and reconstructed with filtered back-projection and sinogram affirmed iterative reconstruction (SAFIRE, strength 5) at 0.6 mm slice thickness. Corresponding 3D idealized, virtual nodule models were co-registered with the CT images to determine each nodule’s location and orientation. Virtual nodules were voxelized, partial volume corrected, and inserted into nodule-free CT data (accounting for system imaging physics) using two methods: projection-based Technique A, and image-based Technique B. Also a third Technique C based on cropping a region of interest from the acquired image of the real nodule and blending it into the nodule-free image was tested. Nodule volumes were measured using a commercial segmentation tool (iNtuition, TeraRecon, Inc.) and deformation was assessed using the Hausdorff distance. Nodule volumes and deformations were compared between the idealized, CT-derived and virtual nodules using a linear mixed effects regression model which utilized the mean, standard deviation, and coefficient of variation (Mea{{n}RHD} , ST{{D}RHD} and C{{V}RHD}{) }~ of the regional Hausdorff distance. Overall, there was a close concordance between the volumes of the CT-derived and

  3. Clinical value of a one-stop-shop low-dose lung screening combined with 18F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer

    International Nuclear Information System (INIS)

    Han, Yeon Hee; Lim, Seok Tae; Jeong, Hwan Jeong; Sohn, Myung Hee

    2016-01-01

    The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with 18F-fluoro-2-deoxyglucose positron emission tomography with CT (18F-FDG PET/CT) compared with conventional lung setting image of 18F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer. From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with 18F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had  >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of 18F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of 18F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed. Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of 18F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were <1 cm in size. The sensitivity, specificity, and diagnostic accuracy of the modalities were 60.6 %, 85.2 %, and 71.1 % for conventional lung setting image and 83.3 %, 88.9 %, and 85.8 % for additional LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional

  4. Clinical value of a one-stop-shop low-dose lung screening combined with {sup 18}F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yeon Hee; Lim, Seok Tae; Jeong, Hwan Jeong; Sohn, Myung Hee [Dept. of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University-Biomedical Research Institute, Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2016-06-15

    The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with 18F-fluoro-2-deoxyglucose positron emission tomography with CT (18F-FDG PET/CT) compared with conventional lung setting image of 18F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer. From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with 18F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had  >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of 18F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of 18F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed. Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of 18F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were <1 cm in size. The sensitivity, specificity, and diagnostic accuracy of the modalities were 60.6 %, 85.2 %, and 71.1 % for conventional lung setting image and 83.3 %, 88.9 %, and 85.8 % for additional LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional

  5. Volumetry of Artificial Pulmonary Nodules in Ex Vivo Porcine Lungs: Comparison of Semi-automated Volumetry and Radiologists' Performance

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ju Hyeon; Kim, Jin Hwan; Kim, Song Soo [Chungnam National University Hospital, Daejeon (Korea, Republic of); Jeon, Ho Sang [Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of); Lee, Hyun Ju [Seoul National University Hospital, Seoul (Korea, Republic of); Park, Noh Hyuck [Kwandong University College of Medicine, Myungji Hospital, Goyang (Korea, Republic of); Cho, Gyu Seong [KAIST, Daejeon (Korea, Republic of)

    2010-10-15

    With the advent of MSCT, the detection rate of small pulmonary nodules is markedly greater. However, there is no definite diagnostic clue to differentiate between malignant and benign nodules, except for the interval growth in small nodule less than 1 cm in diameter. We evaluated the accuracy of computer aided volumetry (CAV) and compared it with 4 radiologists' measurement. Fifteen artificial nodules that were embedded in the ex vivo porcine lung were scanned by MSCT. The diameters and volumes of nodules were independently measured three times, at 5-day intervals, and by four radiologists as well as by CAV. We evaluated the accuracy of the measurements on the basis of the true diameter and volume of the nodules. Using a paired t-test and a Bland-Altman plot, we evaluated whether there was a statistically significant difference between the radiologists' measurements and the CAV. The accuracy of the manual measurements by radiologists revealed a statistically significant difference from the true diameter and volume of the artificial nodules (p<0.01). Conversely, the accuracy of CAV did not show a statistically significant difference with the true nodule diameter and volume (p>0.01) The results of this study suggest that CAV is an accurate and useful tool to evaluate the volume of pulmonary nodules and can eventually be used to differentiate malignant and benign nodules as well as evaluate the therapeutic response of lung cancer.

  6. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-02-15

    Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process. Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule{>=}3 mm,''''nodule<3 mm,'' and ''non-nodule{>=}3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked ''nodule

  7. Computer-assisted solid lung nodule 3D volumetry on CT : influence of scan mode and iterative reconstruction: a CT phantom study

    NARCIS (Netherlands)

    Coenen, Adriaan; Honda, Osamu; van der Jagt, Eric J.; Tomiyama, Noriyuki

    2013-01-01

    To evaluate the effect of high-resolution scan mode and iterative reconstruction on lung nodule 3D volumetry. Solid nodules with various sizes (5, 8, 10 and 12 mm) were placed inside a chest phantom. CT images were obtained with various tube currents, scan modes (conventional mode, high-resolution

  8. Usefulness of computerized method for lung nodule detection on digital chest radiographs using similar subtraction images from different patients

    International Nuclear Information System (INIS)

    Aoki, Takatoshi; Oda, Nobuhiro; Yamashita, Yoshiko; Yamamoto, Keiji; Korogi, Yukunori

    2012-01-01

    Purpose: The purpose of this study is to evaluate the usefulness of a novel computerized method to select automatically the similar chest radiograph for image subtraction in the patients who have no previous chest radiographs and to assist the radiologists’ interpretation by presenting the “similar subtraction image” from different patients. Materials and methods: Institutional review board approval was obtained, and the requirement for informed patient consent was waived. A large database of approximately 15,000 normal chest radiographs was used for searching similar images of different patients. One hundred images of candidates were selected according to two clinical parameters and similarity of the lung field in the target image. We used the correlation value of chest region in the 100 images for searching the most similar image. The similar subtraction images were obtained by subtracting the similar image selected from the target image. Thirty cases with lung nodules and 30 cases without lung nodules were used for an observer performance test. Four attending radiologists and four radiology residents participated in this observer performance test. Results: The AUC for all radiologists increased significantly from 0.925 to 0.974 with the CAD (P = .004). When the computer output images were available, the average AUC for the residents was more improved (0.960 vs. 0.890) than for the attending radiologists (0.987 vs. 0.960). Conclusion: The novel computerized method for lung nodule detection using similar subtraction images from different patients would be useful to detect lung nodules on digital chest radiographs, especially for less experienced readers.

  9. Clinical Value of a One-Stop-Shop Low-Dose Lung Screening Combined with (18)F-FDG PET/CT for the Detection of Metastatic Lung Nodules from Colorectal Cancer.

    Science.gov (United States)

    Han, Yeon-Hee; Lim, Seok Tae; Jeong, Hwan-Jeong; Sohn, Myung-Hee

    2016-06-01

    The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with (18)F-fluoro-2-deoxyglucose positron emission tomography with CT ((18)F-FDG PET/CT) compared with conventional lung setting image of (18)F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer. From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with (18)F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of (18)F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of (18)F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed. Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of (18)F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional lung setting image and additional LD-HRCT were 0.712 and 0.827 respectively. Additional LD-HRCT with maximum inspiration was superior to conventional lung setting image of (18)F-FDG PET

  10. Computer-assisted lung nodule volumetry from multi-detector row CT: Influence of image reconstruction parameters

    International Nuclear Information System (INIS)

    Honda, Osamu; Sumikawa, Hiromitsu; Johkoh, Takeshi; Tomiyama, Noriyuki; Mihara, Naoki; Inoue, Atsuo; Tsubamoto, Mitsuko; Natsag, Javzandulam; Hamada, Seiki; Nakamura, Hironobu

    2007-01-01

    Purpose: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT. Materials and methods: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test. Results: The diameter of the nodules was 8.7 ± 2.7 mm on average, ranging from 4.3 to 16.4 mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p > 0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p < 0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p < 0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5 mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction. Conclusion: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction

  11. Cavitating lung disease due to concomitant drug resistant tuberculosis and invasive pulmonary Aspergillosis in a post-partum patient: A case report.

    Science.gov (United States)

    Ray, Animesh; Suri, J C; Sen, M K; Chakrabarti, S; Gupta, Ayush; Capoor, Malini

    2015-01-01

    Many disorders can present as cavitating lesions in the lung. In this case report, a case of mixed infection with drug resistant tuberculosis and invasive pulmonary aspergillosis in a post-partum patient has been presented. Copyright © 2015 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

  12. Automated detection of lung nodules in multidetector CT: influence of different reconstruction protocols on performance of a software prototype

    International Nuclear Information System (INIS)

    Gurung, J.; Maataoui, A.; Khan, M.; Wetter, A.; Harth, M.; Jacobi, V.; Vogl, T.J.

    2006-01-01

    Purpose: To evaluate the accuracy of software for computer-aided detection (CAD) of lung nodules using different reconstruction slice thickness protocols in multidetector CT. Materials and Methods: Raw image data sets for 15 patients who had undergone 16-row multidetector CT (MDCT) for known pulmonary nodules were reconstructed at a reconstruction thickness of 5.0, 2.0 and 1.0 mm with a reconstruction increment of 1.5, 1.0 and 0.5 mm, respectively. The ''Nodule Enhanced Viewing'' (NEV) tool of LungCare for computer-aided detection of lung nodules was applied to the reconstructed images. The reconstructed images were also blinded and then evaluated by 2 radiologists (A and B). Data from the evaluating radiologists and CAD was then compared to an independent reference standard established using the consensus of 2 independent experienced chest radiologists. The eligible nodules were grouped according to their size (diameter >10, 5 - 10, <5 mm) for assessment. Statistical analysis was performed using the receiver operating characteristic (ROC) curve analysis, t-test and two-rater Cohen's Kappa co-efficient. Results: A total of 103 nodules were included in the reference standard by the consensus panel. The performance of CAD was marginally lower than that of readers at a 5.0-mm reconstruction thickness (AUC = 0.522, 0.517 and 0.497 for A, B and CAD, respectively). In the case of 2.0-mm reconstruction slices, the performance of CAD was better than that of the readers (AUC = 0.524, 0.524 and 0.614 for A, B and CAD, respectively). CAD was found to be significantly superior to radiologists in the case of 1.0-mm reconstruction slices (AUC = 0.537, 0.531 and 0.675 for A, B and CAD, respectively). The sensitivity at a reconstruction thickness of 1.0 mm was determined to be 66.99%, 68.93% and 80.58% for A, B and CAD, respectively. The time required for detection was shortest for CAD at reconstruction slices of 1.0 mm (mean t = 4 min). The performance of radiologists was greatly

  13. An Innocent Appearing Subcutaneous Nodule Diagnoses a Small Cell Lung Cancer in a Never-Smoker Female

    Directory of Open Access Journals (Sweden)

    Nupur Sinha

    2014-01-01

    Full Text Available Lung cancer among never-smokers is recognized as the 7th most common cause of cancer death globally. Adenocarcinoma is the most commonly reported histology. Small cell lung cancer (SCLC has the strongest association with smoking and is rarely reported in never-smokers. Although lung cancer in never-smokers is more common in women, the overall incidence of SCLC in female never-smokers still remains low. Soft tissue metastases from any cancer are rare with an overall prevalence of 1.8%. Soft tissue metastases from lung primary are uncommon, mostly from adenocarcinoma, and portend a poor prognosis. Cutaneous metastases from SCLC are exceptionally rare with reported incidence of 0.3% to 0.8%. We believe ours is the first reported case of SCLC presenting as subcutaneous nodule, in a never-smoker, otherwise asymptomatic female. The diagnosis of SCLC was made incidentally by the excisional biopsy of the subcutaneous nodule. Subsequent CT chest and PET scan revealed a hypermetabolic right lower lobe spiculated lung mass with adrenal and liver involvement. Platinum and etoposide chemotherapy with prophylactic cranial irradiation was initiated for advanced SCLC, and she required further irinotecan and taxol for subsequent pancreatic and adrenal metastases. With continued deterioration, she died approximately 36 months from diagnosis, while under hospice care.

  14. Automatic Approach for Lung Segmentation with Juxta-Pleural Nodules from Thoracic CT Based on Contour Tracing and Correction

    Directory of Open Access Journals (Sweden)

    Jinke Wang

    2016-01-01

    Full Text Available This paper presents a fully automatic framework for lung segmentation, in which juxta-pleural nodule problem is brought into strong focus. The proposed scheme consists of three phases: skin boundary detection, rough segmentation of lung contour, and pulmonary parenchyma refinement. Firstly, chest skin boundary is extracted through image aligning, morphology operation, and connective region analysis. Secondly, diagonal-based border tracing is implemented for lung contour segmentation, with maximum cost path algorithm used for separating the left and right lungs. Finally, by arc-based border smoothing and concave-based border correction, the refined pulmonary parenchyma is obtained. The proposed scheme is evaluated on 45 volumes of chest scans, with volume difference (VD 11.15±69.63 cm3, volume overlap error (VOE 3.5057±1.3719%, average surface distance (ASD 0.7917±0.2741 mm, root mean square distance (RMSD 1.6957±0.6568 mm, maximum symmetric absolute surface distance (MSD 21.3430±8.1743 mm, and average time-cost 2 seconds per image. The preliminary results on accuracy and complexity prove that our scheme is a promising tool for lung segmentation with juxta-pleural nodules.

  15. Evolutionary image simplification for lung nodule classification with convolutional neural networks.

    Science.gov (United States)

    Lückehe, Daniel; von Voigt, Gabriele

    2018-05-29

    Understanding decisions of deep learning techniques is important. Especially in the medical field, the reasons for a decision in a classification task are as crucial as the pure classification results. In this article, we propose a new approach to compute relevant parts of a medical image. Knowing the relevant parts makes it easier to understand decisions. In our approach, a convolutional neural network is employed to learn structures of images of lung nodules. Then, an evolutionary algorithm is applied to compute a simplified version of an unknown image based on the learned structures by the convolutional neural network. In the simplified version, irrelevant parts are removed from the original image. In the results, we show simplified images which allow the observer to focus on the relevant parts. In these images, more than 50% of the pixels are simplified. The simplified pixels do not change the meaning of the images based on the learned structures by the convolutional neural network. An experimental analysis shows the potential of the approach. Besides the examples of simplified images, we analyze the run time development. Simplified images make it easier to focus on relevant parts and to find reasons for a decision. The combination of an evolutionary algorithm employing a learned convolutional neural network is well suited for the simplification task. From a research perspective, it is interesting which areas of the images are simplified and which parts are taken as relevant.

  16. Optimization of a tomosynthesis system for the detection of lung nodules

    International Nuclear Information System (INIS)

    Pineda, Angel R.; Yoon, Sungwon; Paik, David S.; Fahrig, Rebecca

    2006-01-01

    Mathematical observers that track human performance can be used to reduce the number of human observer studies needed to optimize imaging systems. The performance of human observers for the detection of a 3.6 mm lung nodule in anatomical backgrounds was measured as a function of varying tomosynthetic angle and compared with mathematical observers. The human observer results showed a dramatic increase in the percent of correct responses, from 80% in the projection images to 96% in the projection images with a tomosynthetic angle of just 3 degrees. This result suggests the potential usefulness of the scanned beam digital x-ray system for this application. Given the small number of images (40) used per tomosynthetic angle and the highly nonstationary statistical nature of the backgrounds, the nonprewhitening eye observer achieved a higher performance than the channelized Hotelling observer using a Laguerre-Gauss basis. The channelized Hotelling observer with internal noise and the eye filter matched to the projection data were shown to track human performance as the tomosynthetic angle changed. The validation of these mathematical observers extends their applicability to the optimization of tomosynthesis systems

  17. A approach for differential diagnosis of primary lung cancer and breast cancer relapse presenting as a solitary pulmonary nodule in patients after breast surgery

    International Nuclear Information System (INIS)

    Fujita, Takashi; Iwata, Hiroharu; Yatabe, Yasushi

    2009-01-01

    The differential diagnosis of primary lung cancer from metastatic breast cancer is crucial in patients presenting with a solitary pulmonary nodule after breast surgery. However definitive diagnosis of these nodules is often difficult due to similar radiological and pathological features in primary lung and metastatic breast cancer nodules. We assessed the feasibility of our diagnostic approach for these nodules by morphopathological and immunohistochemical examination (thyroid transcription factor-1 (TTF-1), surfactant pro-protein B (SPPB), estrogen receptor (ER), mammaglobin-1 (MGB1)), and estimated the frequency of primary lung cancer occurrence in 23 breast cancer patients. Biopsy specimens were obtained using CT-guided needle biopsy (NB) and transbronchial lung biopsy (TBLB) in 21 patients (91.3%). Surgical resection was performed for diagnosis and treatment in two patients. Differential diagnosis was obtained by morphopathological methods alone in 17 patients (73.9%, primary lung cancer: 6 cases, metastatic breast cancer: 11 cases) and by immunohistochemical examination in the remaining 6 (26.1%, primary lung cancer: 1 case, metastatic breast cancer: 5 cases). Our results show the clinical feasibility of our approach to the differential diagnosis of breast cancer relapse and primary lung cancer presenting as a solitary nodule in breast cancer patients. (author)

  18. CT and histopathologic characteristics of lung adenocarcinoma with pure ground-glass nodules 10 mm or less in diameter

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fang [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Capital Medical University, Department of Radiology, Xuanwu Hospital, Beijing (China); Tian, Shu-ping [Navy General Hospital, Department of Radiology, Beijing (China); Jin, Xin; Jing, Rui; Yang, Yue-qing; Jin, Mei; Zhao, Shao-hong [Chinese PLA General Hospital, Department of Radiology, Beijing (China)

    2017-10-15

    To evaluate CT and histopathologic features of lung adenocarcinoma with pure ground-glass nodule (pGGN) ≤10 mm in diameter. CT appearances of 148 patients (150 lesions) who underwent curative resection of lung adenocarcinoma with pGGN ≤10 mm (25 atypical adenomatous hyperplasias, 42 adenocarcinoma in situs, 38 minimally invasive adenocarcinomas, and 45 invasive pulmonary adenocarcinomas) were analyzed for lesion size, density, bubble-like sign, air bronchogram, vessel changes, margin, and tumour-lung interface. CT characteristics were compared among different histopathologic subtypes. Univariate and multivariate analysis were used to assess the relationship between CT characteristics of pGGN and lesion invasiveness, respectively. There were statistically significant differences among histopathologic subtypes in lesion size, vessel changes, and tumour-lung interface (P<0.05). Univariate analysis revealed significant differences of vessel changes, margin and tumour-lung interface between preinvasive and invasive lesions (P<0.05). Logistic regression analysis showed that the vessel changes, unsmooth margin and clear tumour-lung interface were significant predictive factors for lesion invasiveness, with odds ratios (95% CI) of 2.57 (1.17-5.62), 1.83 (1.25-2.68) and 4.25 (1.78-10.14), respectively. Invasive lesions are found in 55.3% of subcentimeter pGGNs in our cohort. Vessel changes, unsmooth margin, and clear lung-tumour interface may indicate the invasiveness of lung adenocarcinoma with subcentimeter pGGN. (orig.)

  19. Computerized detection of lung nodules by means of "virtual dual-energy" radiography.

    Science.gov (United States)

    Chen, Sheng; Suzuki, Kenji

    2013-02-01

    Major challenges in current computer-aided detection (CADe) schemes for nodule detection in chest radiographs (CXRs) are to detect nodules that overlap with ribs and/or clavicles and to reduce the frequent false positives (FPs) caused by ribs. Detection of such nodules by a CADe scheme is very important, because radiologists are likely to miss such subtle nodules. Our purpose in this study was to develop a CADe scheme with improved sensitivity and specificity by use of "virtual dual-energy" (VDE) CXRs where ribs and clavicles are suppressed with massive-training artificial neural networks (MTANNs). To reduce rib-induced FPs and detect nodules overlapping with ribs, we incorporated the VDE technology in our CADe scheme. The VDE technology suppressed rib and clavicle opacities in CXRs while maintaining soft-tissue opacity by use of the MTANN technique that had been trained with real dual-energy imaging. Our scheme detected nodule candidates on VDE images by use of a morphologic filtering technique. Sixty morphologic and gray-level-based features were extracted from each candidate from both original and VDE CXRs. A nonlinear support vector classifier was employed for classification of the nodule candidates. A publicly available database containing 140 nodules in 140 CXRs and 93 normal CXRs was used for testing our CADe scheme. All nodules were confirmed by computed tomography examinations, and the average size of the nodules was 17.8 mm. Thirty percent (42/140) of the nodules were rated "extremely subtle" or "very subtle" by a radiologist. The original scheme without VDE technology achieved a sensitivity of 78.6% (110/140) with 5 (1165/233) FPs per image. By use of the VDE technology, more nodules overlapping with ribs or clavicles were detected and the sensitivity was improved substantially to 85.0% (119/140) at the same FP rate in a leave-one-out cross-validation test, whereas the FP rate was reduced to 2.5 (583/233) per image at the same sensitivity level as the

  20. Computerized Detection of Lung Nodules by Means of “Virtual Dual-Energy” Radiography

    Science.gov (United States)

    Chen, Sheng; Suzuki, Kenji

    2014-01-01

    Major challenges in current computer-aided detection (CADe) schemes for nodule detection in chest radiographs (CXRs) are to detect nodules that overlap with ribs and/or clavicles and to reduce the frequent false positives (FPs) caused by ribs. Detection of such nodules by a CADe scheme is very important, because radiologists are likely to miss such subtle nodules. Our purpose in this study was to develop a CADe scheme with improved sensitivity and specificity by use of “virtual dual-energy” (VDE) CXRs where ribs and clavicles are suppressed with massive-training artificial neural networks (MTANNs). To reduce rib-induced FPs and detect nodules overlapping with ribs, we incorporated the VDE technology in our CADe scheme. The VDE technology suppressed rib and clavicle opacities in CXRs while maintaining soft-tissue opacity by use of the MTANN technique that had been trained with real dual-energy imaging. Our scheme detected nodule candidates on VDE images by use of a morphologic filtering technique. Sixty morphologic and gray-level-based features were extracted from each candidate from both original and VDE CXRs. A nonlinear support vector classifier was employed for classification of the nodule candidates. A publicly available database containing 140 nodules in 140 CXRs and 93 normal CXRs was used for testing our CADe scheme. All nodules were confirmed by computed tomography examinations, and the average size of the nodules was 17.8 mm. Thirty percent (42/140) of the nodules were rated “extremely subtle” or “very subtle” by a radiologist. The original scheme without VDE technology achieved a sensitivity of 78.6% (110/140) with 5 (1165/233) FPs per image. By use of the VDE technology, more nodules overlapping with ribs or clavicles were detected and the sensitivity was improved substantially to 85.0% (119/140) at the same FP rate in a leave-one-out cross-validation test, whereas the FP rate was reduced to 2.5 (583/233) per image at the same sensitivity

  1. Data-driven decision support for radiologists: re-using the National Lung Screening Trial dataset for pulmonary nodule management.

    Science.gov (United States)

    Morrison, James J; Hostetter, Jason; Wang, Kenneth; Siegel, Eliot L

    2015-02-01

    Real-time mining of large research trial datasets enables development of case-based clinical decision support tools. Several applicable research datasets exist including the National Lung Screening Trial (NLST), a dataset unparalleled in size and scope for studying population-based lung cancer screening. Using these data, a clinical decision support tool was developed which matches patient demographics and lung nodule characteristics to a cohort of similar patients. The NLST dataset was converted into Structured Query Language (SQL) tables hosted on a web server, and a web-based JavaScript application was developed which performs real-time queries. JavaScript is used for both the server-side and client-side language, allowing for rapid development of a robust client interface and server-side data layer. Real-time data mining of user-specified patient cohorts achieved a rapid return of cohort cancer statistics and lung nodule distribution information. This system demonstrates the potential of individualized real-time data mining using large high-quality clinical trial datasets to drive evidence-based clinical decision-making.

  2. Massive training artificial neural network (MTANN) for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Armato, Samuel G. III; Li, Feng; Sone, Shusuke; Doi, Kunio

    2003-01-01

    In this study, we investigated a pattern-recognition technique based on an artificial neural network (ANN), which is called a massive training artificial neural network (MTANN), for reduction of false positives in computerized detection of lung nodules in low-dose computed tomography (CT) images. The MTANN consists of a modified multilayer ANN, which is capable of operating on image data directly. The MTANN is trained by use of a large number of subregions extracted from input images together with the teacher images containing the distribution for the 'likelihood of being a nodule'. The output image is obtained by scanning an input image with the MTANN. The distinction between a nodule and a non-nodule is made by use of a score which is defined from the output image of the trained MTANN. In order to eliminate various types of non-nodules, we extended the capability of a single MTANN, and developed a multiple MTANN (Multi-MTANN). The Multi-MTANN consists of plural MTANNs that are arranged in parallel. Each MTANN is trained by using the same nodules, but with a different type of non-nodule. Each MTANN acts as an expert for a specific type of non-nodule, e.g., five different MTANNs were trained to distinguish nodules from various-sized vessels; four other MTANNs were applied to eliminate some other opacities. The outputs of the MTANNs were combined by using the logical AND operation such that each of the trained MTANNs eliminated none of the nodules, but removed the specific type of non-nodule with which the MTANN was trained, and thus removed various types of non-nodules. The Multi-MTANN consisting of nine MTANNs was trained with 10 typical nodules and 10 non-nodules representing each of nine different non-nodule types (90 training non-nodules overall) in a training set. The trained Multi-MTANN was applied to the reduction of false positives reported by our current computerized scheme for lung nodule detection based on a database of 63 low-dose CT scans (1765

  3. Lung cancer risk and cancer-specific mortality in subjects undergoing routine imaging test when stratified with and without identified lung nodule on imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Saez, Noemi [Miguel Hernandez University, Public Health, History of Science and Ginecology Department, Alicante (Spain); Hernandez-Aguado, Ildefonso; Pastor Valero, Maria; Parker, Lucy Anne; Lumbreras, Blanca [Miguel Hernandez University, Public Health, History of Science and Ginecology Department, Alicante (Spain); CIBER en Epidemiologia y Salud Publica, Madrid (Spain); Vilar, Jose; Domingo, Maria Luisa [Peset Hospital, Radiodiagnostic Department, Valencia (Spain); Gonzalez-Alvarez, Isabel; Lorente, Maria Fermina [San Juan Hospital, Radiodiagnostic Department, San Juan de Alicante (Spain)

    2015-12-15

    To assess the risk of lung cancer and specific mortality rate in patients with and without solitary pulmonary nodules (SPN) on chest radiograph and CT. This prospective study included 16,078 patients ≥35 years old (893 of them had an SPN detected with either chest radiograph or CT) and 15,185 without SPN. Patients were followed up for 18 months or until being diagnosed with lung cancer. Risk and mortality lung cancer were calculated in both groups with Poisson regression. In patients with SPN, incidence of lung cancer was 8.3 % (95 % CI 6.0-11.2) on radiograph and 12.4 % (95 % CI 9.3-15.9) on CT. A chronic obstructive pulmonary disease in patients with radiographs (odds ratio 2.62; 95 % CI 1.03, 6.67) and smoking habit (odds ratio 20.63; 95 % CI 3.84, 110.77) in patients with CT were associated with a higher probability of lung cancer. Large nodule size and spiculated edge were associated with lung cancer on both CT and radiograph. Lung cancer-specific mortality was lower in patients with SPN than in those without SPN (1.73/1000 person-years, 95 % CI 1.08-2.88 vs. 2.15/1000 person-years, 95 % CI 1.25-3.96). The risk of lung cancer for patients with SPN is higher in clinical populations than in screening studies. Moreover, patients with SPN showed lower mortality than those without SPN. (orig.)

  4. Lung cancer risk and cancer-specific mortality in subjects undergoing routine imaging test when stratified with and without identified lung nodule on imaging study

    International Nuclear Information System (INIS)

    Gomez-Saez, Noemi; Hernandez-Aguado, Ildefonso; Pastor Valero, Maria; Parker, Lucy Anne; Lumbreras, Blanca; Vilar, Jose; Domingo, Maria Luisa; Gonzalez-Alvarez, Isabel; Lorente, Maria Fermina

    2015-01-01

    To assess the risk of lung cancer and specific mortality rate in patients with and without solitary pulmonary nodules (SPN) on chest radiograph and CT. This prospective study included 16,078 patients ≥35 years old (893 of them had an SPN detected with either chest radiograph or CT) and 15,185 without SPN. Patients were followed up for 18 months or until being diagnosed with lung cancer. Risk and mortality lung cancer were calculated in both groups with Poisson regression. In patients with SPN, incidence of lung cancer was 8.3 % (95 % CI 6.0-11.2) on radiograph and 12.4 % (95 % CI 9.3-15.9) on CT. A chronic obstructive pulmonary disease in patients with radiographs (odds ratio 2.62; 95 % CI 1.03, 6.67) and smoking habit (odds ratio 20.63; 95 % CI 3.84, 110.77) in patients with CT were associated with a higher probability of lung cancer. Large nodule size and spiculated edge were associated with lung cancer on both CT and radiograph. Lung cancer-specific mortality was lower in patients with SPN than in those without SPN (1.73/1000 person-years, 95 % CI 1.08-2.88 vs. 2.15/1000 person-years, 95 % CI 1.25-3.96). The risk of lung cancer for patients with SPN is higher in clinical populations than in screening studies. Moreover, patients with SPN showed lower mortality than those without SPN. (orig.)

  5. Differential diagnosis of a solitary pulmonary nodule of the lung on the grounds of selected laboratory tests and radiological examination

    International Nuclear Information System (INIS)

    Szlachcinska, A.; Kozak, J.

    2011-01-01

    Objective: To present in detail the diagnosis of solitary pulmonary nodule and especially evaluation of: clinical data, analysis of radiological images, selected laboratory tests. Material and methods: There were 50 patients - 31 men and 19 women at the mean age 58.7 ± 11.4 years old who underwent surgical treatment because of a solitary pulmonary nodule. Interview, physical examination, computed tomography, bronchoscopy, spirometry, and laboratory tests needed for the operation were performed in all these patients. Additionally LDH, fibrinogen, ESR, and the tumour markers CEA, Ca 15-3, Ca 19-9, NSE, SCC, and Cyfra 21-1 were measured from the blood sample collected during admission. Results: Malignant tumour was diagnosed in 24 patients, benign in 26. There is a significant difference between patients with malignant and nonmalignant tumours in age (54.46 years vs. 63.33 years), size of the tumour in the lung scan of chest CT (1.53 cm vs. 1.91 cm) and location (lower right lobe vs. upper right lobe). There is no significant difference between type of tumour and sex, clinical symptoms and laboratory tests. Conclusions: 1. The risk factors of malignancy in patient with solitary pulmonary nodule are: age ≥ 56.5 years, size of the tumour in the lung scan of chest CT ≥ 1.45 cm, location in upper right lobe. 2. LDH, fibrinogen, ESR, and the tumour markers CEA, Ca 15-3, Ca 19-9, NSE, SCC, and Cyfra 21-1 are not useful in differential diagnosis of solitary pulmonary nodule. (authors)

  6. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans

    International Nuclear Information System (INIS)

    2011-01-01

    Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process. Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule≥3 mm,''''nodule<3 mm,'' and ''non-nodule≥3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked ''nodule≥3 mm'' by at least one radiologist, of which 928 (34.7%) received such marks from all

  7. Whether and under what conditions FDG-PET might be cost-effective in evaluating solitary pulmonary nodules depicted on lung cancer screening in Japan

    International Nuclear Information System (INIS)

    Tsushima, Yoshito; Aoki, Jun; Endo, Keigo

    2003-01-01

    The purpose of this study was to determine whether and under what conditions fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) may be cost-effective in evaluating solitary pulmonary nodules depicted on lung cancer screening in Japan. Three decision models for differentiating lung cancer from benign nodules were compared: CT alone, PET alone, and CT plus PET. The various paths of each strategy were dependent on variables determined from a review of the medical literature. Costs were based on Japanese health insurance. The prevalence of lung cancer among solitary pulmonary nodules detected on lung cancer screening was less than 10%. For this prevalence, the CT-plus-PET model was the cost-effective alternative to the CT-alone model (cost savings were 64,000 yen per patient) and provided greater accuracy (0.90 vs. 0.84). Both of these effects were the result of reducing the number of candidates who undergo unnecessary CT-guided or bronchofiberscopic biopsies or thoracotomy for a benign pulmonary nodule. The CT-plus-PET strategy is accurate and cost-effective for the characterization of solitary pulmonary nodules detected on lung cancer screening in Japan. (author)

  8. Correlation of emphysema score with perceived malignancy of pulmonary nodules: a multi-observer study using the LIDC-IDRI CT lung database

    Science.gov (United States)

    Wiemker, Rafael; Bülow, Thomas; Blaffert, Thomas; Dharaiya, Ekta

    2009-02-01

    Presence of emphysema is recognized to be one of the single most significant risk factors in risk models for the prediction of lung cancer. Therefore, an automatically computed emphysema score would be a prime candidate as an additional numerical feature for computer aided diagnosis (CADx) for indeterminate pulmonary nodules. We have applied several histogram-based emphysema scores to 460 thoracic CT scans from the IDRI CT lung image database, and analyzed the emphysema scores in conjunction with 3000 nodule malignancy ratings of 1232 pulmonary nodules made by expert observers. Despite the emphysema being a known risk factor, we have not found any impact on the readers' malignancy rating of nodules found in a patient with higher emphysema score. We have also not found any correlation between the number of expert-detected nodules in a patient and his emphysema score, or the relative craniocaudal location of the nodules and their malignancy rating. The inter-observer agreement of the expert ratings was excellent on nodule diameter (as derived from manual delineations), good for calcification, and only modest for malignancy and shape descriptions such as spiculation, lobulation, margin, etc.

  9. Emphysema and soluble CD14 are associated with pulmonary nodules in HIV-infected patients: implications for lung cancer screening.

    Science.gov (United States)

    Triplette, Matthew; Sigel, Keith M; Morris, Alison; Shahrir, Shahida; Wisnivesky, Juan P; Kong, Chung Y; Diaz, Phillip T; Petraglia, Alycia; Crothers, Kristina

    2017-07-31

    Lung cancer screening may benefit HIV-infected (HIV) smokers because of an elevated risk of lung cancer, but may have unique harms because of HIV-specific risk factors for false-positive screens. This study seeks to understand whether inflammatory biomarkers and markers of chronic lung disease are associated with noncalcified nodules at least 4 mm (NCN) in HIV compared with uninfected patients. This is a cohort study of Examinations of HIV-Associated Lung Emphysema (EXHALE), including 158 HIV and 133 HIV-uninfected participants. Participants underwent a laboratory assessment [including measurement of D-dimer, interleukin 6, and soluble CD14 (sCD14)], chest computed tomography (CT), and pulmonary function testing. We created multivariable logistic regression models to determine predictors of NCN in the participants stratified by HIV status, with attention to semiqualitative scoring of radiographic emphysema, markers of pulmonary function, and inflammatory biomarkers. Of the 291 participants, 69 had NCN on chest CT. As previously reported, there was no difference in prevalence of these nodules by HIV status. Emphysema and elevated sCD14 demonstrated an association with NCN in HIV participants independent of smoking status, CD4 cell count, HIV viral load, and pulmonary function. Emphysema and sCD14, a marker of immune activation, was associated with a higher prevalence of NCN on chest CT in HIV participants. Patients with chronic immune activation and emphysema may be at higher risk for both false-positive findings and incident lung cancer, thus screening in this group requires further study to understand the balance of benefits and harms.

  10. Granulomatous Bronchiolitis with Necrobiotic Pulmonary Nodules in Chrohn's Disease

    Directory of Open Access Journals (Sweden)

    Hugh J Freeman

    2004-01-01

    Full Text Available A 37-year-old man with extensive Crohn's disease of the stomach, small and large intestine for almost a decade developed respiratory symptoms and radiological findings suggestive of pneumonia that failed to resolve with antibiotic treatment. Computed tomography scanning of his lungs showed extensive changes with cavitated parenchymal nodules. Histological evaluation of an open lung biopsy showed granulomatous bronchiolitis and pulmonary necrobiosis. Treatment with steroids and immunosuppression resulted in complete resolution of his clinical symptoms of pneumonia and abnormal computed tomography imaging changes. Granulomatous bronchiolitis and necrobiotic nodules may be a manifestation of Crohn's disease in the absence of microbial agents, including mycobacteria or fungal agents. While a multiplicity of complex pulmonary changes may occur in Crohn's disease, their clinical recognition and precise pathological definition may be particularly important if treatment with a biological agent, such as infliximab, is being considered.

  11. Parametric features of image textures in 18F-FDG PET/CT evaluation of lung nodules

    International Nuclear Information System (INIS)

    Wang Changmei; Guan Yihui; Zhang Wenqiang; Zuo Chuantao; Hua Fengchun

    2013-01-01

    Objective: To evaluate the parametric features of image textures on 18 F-FDG PET/CT for the differentiation between malignant and benign pulmonary nodules and compare the diagnostic performance of these parameters with SUV max . Methods: 18 F-FDG PET/CT images of 170 patients (102 males, 68 females, age range: 29-81 (mean 59) years) with pulmonary nodules were retrospectively evaluated. Eighty-nine pulmonary nodules (230 slices) were malignant and 81 (193 slices) were benign. The pulmonary nodules were contoured on CT images and mapped to the co-registered PET images. Thirteen parameters of textural features were extracted and SUV max was measured. Logistic regression analysis was used to identify the significant texture parameters and create a regression model. The efficacy of the textural features and SUV max to distinguish between malignant and benign pulmonary nodules was evaluated by ROC curve analysis. The textural features of squamous cell carcinoma and adenocarcinoma were compared via the Mann-Whitney u test. The sensitivity and specificity of the textural features and SUV max for the differential diagnosis were compared with χ 2 test. Results: Logistic regression model identified 4 textural features (skewness (β=1.7058), kurtosis (β=-1.0989), angular second moment (ASM, 3=-4.4140) and strength (β=0.5626); all P<0.05) to have significant correlation with the malignancy of lung nodules. The AUC of ROC curve was 0.775 (95% CI 0.732-0.819; P<0.001) with the sensitivity of 89.6% (206/230) and specificity of 50.8% (98/193). ASM and strength had statistically significant differences between squamous cell carcinoma and adenocarcinoma [ASM: 0.0303 (95% CI 0.0392-0.0724) vs 0.0594 (95% CI 0.0721-0.0947); strength: 2.4714 (95% CI 2.4632-4.1050) vs 1.5945 (95% CI 1.9003-2.4652); u=3082.0 and 3115.0, both P<0.01]. The AUC of SUV max -based diagnosis was 0.757 (95% CI 0.711-0.802; P<0.001) with the sensitivity of 80.9% (186/230) and specificity of 50.3% (97/193) at

  12. Nodule Detection in a Lung Region that's Segmented with Using Genetic Cellular Neural Networks and 3D Template Matching with Fuzzy Rule Based Thresholding

    International Nuclear Information System (INIS)

    Ozekes, Serhat; Osman, Onur; Ucan, N.

    2008-01-01

    The purpose of this study was to develop a new method for automated lung nodule detection in serial section CT images with using the characteristics of the 3D appearance of the nodules that distinguish themselves from the vessels. Lung nodules were detected in four steps. First, to reduce the number of region of interests (ROIs) and the computation time, the lung regions of the CTs were segmented using Genetic Cellular Neural Networks (G-CNN). Then, for each lung region, ROIs were specified with using the 8 directional search; +1 or -1 values were assigned to each voxel. The 3D ROI image was obtained by combining all the 2-Dimensional (2D) ROI images. A 3D template was created to find the nodule-like structures on the 3D ROI image. Convolution of the 3D ROI image with the proposed template strengthens the shapes that are similar to those of the template and it weakens the other ones. Finally, fuzzy rule based thresholding was applied and the ROI's were found. To test the system's efficiency, we used 16 cases with a total of 425 slices, which were taken from the Lung Image Database Consortium (LIDC) dataset. The computer aided diagnosis (CAD) system achieved 100% sensitivity with 13.375 FPs per case when the nodule thickness was greater than or equal to 5.625 mm. Our results indicate that the detection performance of our algorithm is satisfactory, and this may well improve the performance of computer aided detection of lung nodules

  13. Excavated pulmonary nodules: an unusual clinical presentation of lung metastasis in two cases

    Directory of Open Access Journals (Sweden)

    Lalya Issam

    2010-06-01

    Full Text Available Abstract Background Excavated pulmonary metastasis are rare. We present two cases of excavated pulmonary nodules proved to be metastases from osteosarcoma and gallblader lymphoma. Case presentation The first one is 39-year-old man in whom cholecystectomy made the diagnosis of primary non-Hodgkin's lymphoma of the gallbladder. He presented in chest CT scan excavated nodules that had been biopsied and confirmed the diagnosis of non hodgkin lymphoma. He underwent 8 courses of chemotherapy CHOP 21 with complete remission. The second one is an 21 years old man who presented a right leg osteoblastic osteosarcoma with only excavated pulmonary nodules in extension assessment. He had 3 courses of polychemotherapy API (doxorubicin, platinum, and ifosfamide with partial response. Unfortunately, he died following a septic shock. Review of the literature shows that excavated pulmonary nodules as metastasis are rare but we should consider this diagnosis every time we are in front of a cancer. Chest computed tomography is the best diagnosis imaging that could make this diagnosis. Differential diagnosis between benign and malignant bullous lesions is important because surgical excision affects survival in some malignancies. Conclusions Although pulmonary nodules are the most common cancer metastasis, a differential diagnosis of a concurrent primary malignancy should always be considered every time we have excavated lesions, even in patients with known malignant disease. Thorough chest evaluation is important, as multiple primary malignancies may occur concomitantly.

  14. TH-CD-207B-10: Effect of CT Reconstruction Filter On Measured Hounsfield Values in Lung Nodules

    Energy Technology Data Exchange (ETDEWEB)

    Little, K; Reiser, I; Sanchez, A; Chung, J; MacMahon, H; Lu, Z [The University of Chicago, Chicago, IL (United States)

    2016-06-15

    Purpose: Measured Hounsfield numbers in CT are used by radiologists to determine the presence of calcium or fat in lung nodules, either of which suggests a benign diagnosis. However, substantial variations in Hounsfield number may arise due to the use of different reconstruction parameters such as the filter/kernel, leading to measurement inaccuracies. This quality improvement project was developed to demonstrate measurement pitfalls and to identify acceptable conditions for incorporating Hounsfield values as a factor in lung nodule diagnosis. Methods: 12 mm-diameter spheres of polyurethane and urethane foam were placed into an anthropomorphic chest phantom, and 10 mm-diameter tubes with varying iodine concentrations were placed into a 16 cm PMMA cylindrical phantom. Additionally, 11 mm-diameter PMMA and HDPE spheres were placed in a 10 cm PMMA cylindrical phantom. Phantoms were scanned at 120 kVp using a Siemens Biograph mCT and on a Philips iCT and reconstructed using various reconstruction filters. Results: For the Siemens system, both sharp kernels and smooth kernels altered the Hounsfield numbers. Hounsfield numbers varied within a range of 8.9 HU for urethane foam and varied within 58.7 HU for polyurethane. The iodine measurements varied up to 37.9 HU for the lowest concentration. For the Philips system, Hounsfield numbers were relatively consistent but were higher for the “Detail” and “Lung Enhanced” filters, varying by 36.9 HU for PMMA and 15.9 HU for HDPE. Conclusion: Reconstruction filters can change the measured Hounsfield numbers of nodular objects, especially with detail-enhancing (sharpening) filters commonly used in lung imaging. Measured values should only be used for diagnostic decision support with filters that have demonstrated accuracy and consistency. While filter accuracy statements are available from manufacturers, radiologists are likely not aware of the extent of potential variations that can occur in a clinical setting.

  15. Eye-tracking of nodule detection in lung CT volumetric data

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Ivan; Verdun, Francis R.; Bochud, François O., E-mail: francois.bochud@chuv.ch [Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1004 (Switzerland); Schmidt, Sabine [Department of Radiology, Lausanne University Hospital, Lausanne 1004 (Switzerland)

    2015-06-15

    Purpose: Signal detection on 3D medical images depends on many factors, such as foveal and peripheral vision, the type of signal, and background complexity, and the speed at which the frames are displayed. In this paper, the authors focus on the speed with which radiologists and naïve observers search through medical images. Prior to the study, the authors asked the radiologists to estimate the speed at which they scrolled through CT sets. They gave a subjective estimate of 5 frames per second (fps). The aim of this paper is to measure and analyze the speed with which humans scroll through image stacks, showing a method to visually display the behavior of observers as the search is made as well as measuring the accuracy of the decisions. This information will be useful in the development of model observers, mathematical algorithms that can be used to evaluate diagnostic imaging systems. Methods: The authors performed a series of 3D 4-alternative forced-choice lung nodule detection tasks on volumetric stacks of chest CT images iteratively reconstructed in lung algorithm. The strategy used by three radiologists and three naïve observers was assessed using an eye-tracker in order to establish where their gaze was fixed during the experiment and to verify that when a decision was made, a correct answer was not due only to chance. In a first set of experiments, the observers were restricted to read the images at three fixed speeds of image scrolling and were allowed to see each alternative once. In the second set of experiments, the subjects were allowed to scroll through the image stacks at will with no time or gaze limits. In both static-speed and free-scrolling conditions, the four image stacks were displayed simultaneously. All trials were shown at two different image contrasts. Results: The authors were able to determine a histogram of scrolling speeds in frames per second. The scrolling speed of the naïve observers and the radiologists at the moment the signal

  16. Evaluation of effectiveness of a computer system (CAD) in the identification of lung nodules with low-dose MSCT: scanning technique and preliminary results

    International Nuclear Information System (INIS)

    Fraioli, Francesco; Catalano, Carlo; Almberger, Maria; Bertoletti, Linda; Cantisani, Vito; Danti, Massimiliano; Pediconi, Federica; Passariello, Roberto

    2005-01-01

    Purpose: Evaluation of the effectiveness of a computer-aided diagnosis (CAD) in the identification of pulmonary nodules. Materials and methods: Two observers (A1, A2) with different levels of experience independently evaluated 20 chest MSCT studies with and without the aid of a CAD system (LungCheck, R2 Technology, Inc.). The study parameters were as follows: 140 kVs, 40 mAs, collimation 4x1 mm, slice thickness 1.25 mm, reconstruction interval 1.0 mm. The observers analysed the images with and without CAD and evaluated: 1) nodule size (longer axis); 2) number and location of nodules; 3) reading time for each observer. The gold standard was represented by the evaluation of both readers in consensus with the aid of the CAD system. Results: Without CAD support the two readers identified 77 (A1) and 79 (A2) nodules and with CAD 81 (A1) and 82 (A2) nodules. Working in consensus the two observers identified 81 nodules without the aid of CAD and 84 nodules with the aid of CAD. Total number of nodules identified by CAD was 104, 25 of which were false positive and 5 false negative. The average reading time with the aid of CAD decreased by as much as 40% for both the observers. Conclusions: The preliminary results of our study suggest that the CAD technique is an accurate automatic support tool in the identification of pulmonary nodules. It reduces reading time and automatically supplies the size, volume, density and number of nodules, thus being useful both in screening programmes and in the follow-up of cancer patients, in whom comparison of the images is particularly difficult [it

  17. Benefit of computer-aided detection analysis for the detection of subsolid and solid lung nodules on thin- and thick-section CT.

    Science.gov (United States)

    Godoy, Myrna C B; Kim, Tae Jung; White, Charles S; Bogoni, Luca; de Groot, Patricia; Florin, Charles; Obuchowski, Nancy; Babb, James S; Salganicoff, Marcos; Naidich, David P; Anand, Vikram; Park, Sangmin; Vlahos, Ioannis; Ko, Jane P

    2013-01-01

    The objective of our study was to evaluate the impact of computer-aided detection (CAD) on the identification of subsolid and solid lung nodules on thin- and thick-section CT. For 46 chest CT examinations with ground-glass opacity (GGO) nodules, CAD marks computed using thin data were evaluated in two phases. First, four chest radiologists reviewed thin sections (reader(thin)) for nodules and subsequently CAD marks (reader(thin) + CAD(thin)). After 4 months, the same cases were reviewed on thick sections (reader(thick)) and subsequently with CAD marks (reader(thick) + CAD(thick)). Sensitivities were evaluated. Additionally, reader(thick) sensitivity with assessment of CAD marks on thin sections was estimated (reader(thick) + CAD(thin)). For 155 nodules (mean, 5.5 mm; range, 4.0-27.5 mm)-74 solid nodules, 22 part-solid (part-solid nodules), and 59 GGO nodules-CAD stand-alone sensitivity was 80%, 95%, and 71%, respectively, with three false-positives on average (0-12) per CT study. Reader(thin) + CAD(thin) sensitivities were higher than reader(thin) for solid nodules (82% vs 57%, p thick), reader(thick) + CAD(thick), reader(thick) + CAD(thin) were 40%, 58% (p thick); false-positive rates were 1.17, 1.19, and 1.26 per case for reader(thick), reader(thick) + CAD(thick), and reader(thick) + CAD(thin), respectively. Detection of GGO nodules and solid nodules is significantly improved with CAD. When interpretation is performed on thick sections, the benefit is greater when CAD marks are reviewed on thin rather than thick sections.

  18. Prognostic importance of pleural attachment status measured by pretreatment CT images in patients with stage IA lung adenocarcinoma: measurement of the ratio of the interface between nodule and neighboring pleura to nodule surface area

    Science.gov (United States)

    Kawata, Y.; Niki, N.; Kusumoto, M.; Ohmatsu, H.; Aokage, K.; Ishii, G.; Matsumoto, Y.; Tsuchida, T.; Eguchi, K.; Kaneko, M.

    2018-02-01

    Screening for lung cancer with low-dose computed tomography (CT) has led to increased recognition of small lung cancers and is expected to increase the rate of detection of early-stage lung cancer. Major concerns in the implementation of the CT screening of large populations include determining the appropriate management of pulmonary nodules found on a scan. The identification of patients with early-stage lung cancer who have a higher risk for relapse and who require more aggressive surveillance has been a target of intense investigation. This study was performed to investigate whether image features of internal intensity in combination with surrounding structure characteristics are associated with an increased risk of relapse in patients with stage IA lung adenocarcinoma. We focused on pleural attachment status which is one of morphological characteristics associated with prognosis in three-dimensional thoracic CT images.

  19. Cloud-Based NoSQL Open Database of Pulmonary Nodules for Computer-Aided Lung Cancer Diagnosis and Reproducible Research.

    Science.gov (United States)

    Ferreira Junior, José Raniery; Oliveira, Marcelo Costa; de Azevedo-Marques, Paulo Mazzoncini

    2016-12-01

    Lung cancer is the leading cause of cancer-related deaths in the world, and its main manifestation is pulmonary nodules. Detection and classification of pulmonary nodules are challenging tasks that must be done by qualified specialists, but image interpretation errors make those tasks difficult. In order to aid radiologists on those hard tasks, it is important to integrate the computer-based tools with the lesion detection, pathology diagnosis, and image interpretation processes. However, computer-aided diagnosis research faces the problem of not having enough shared medical reference data for the development, testing, and evaluation of computational methods for diagnosis. In order to minimize this problem, this paper presents a public nonrelational document-oriented cloud-based database of pulmonary nodules characterized by 3D texture attributes, identified by experienced radiologists and classified in nine different subjective characteristics by the same specialists. Our goal with the development of this database is to improve computer-aided lung cancer diagnosis and pulmonary nodule detection and classification research through the deployment of this database in a cloud Database as a Service framework. Pulmonary nodule data was provided by the Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI), image descriptors were acquired by a volumetric texture analysis, and database schema was developed using a document-oriented Not only Structured Query Language (NoSQL) approach. The proposed database is now with 379 exams, 838 nodules, and 8237 images, 4029 of them are CT scans and 4208 manually segmented nodules, and it is allocated in a MongoDB instance on a cloud infrastructure.

  20. Malignancy risk estimation of screen-detected nodules at baseline CT: comparison of the PanCan model, Lung-RADS and NCCN guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Riel, Sarah J. van; Ciompi, Francesco; Jacobs, Colin; Scholten, Ernst T.; Prokop, Mathias; Ginneken, Bram van [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Winkler Wille, Mathilde M.; Naqibullah, Matiullah [University of Copenhagen, Department of Pulmonology Gentofte Hospital, Hellerup (Denmark); Lam, Stephen [British Columbia Cancer Agency, Department of Integrative Oncology, Vancouver, British Columbia (Canada); Schaefer-Prokop, Cornelia [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Meander Medical Center, Department of Radiology, Amersfoort (Netherlands)

    2017-10-15

    To compare the PanCan model, Lung-RADS and the 1.2016 National Comprehensive Cancer Network (NCCN) guidelines for discriminating malignant from benign pulmonary nodules on baseline screening CT scans and the impact diameter measurement methods have on performances. From the Danish Lung Cancer Screening Trial database, 64 CTs with malignant nodules and 549 baseline CTs with benign nodules were included. Performance of the systems was evaluated applying the system's original diameter definitions: D{sup longest-C} (PanCan), D{sup meanAxial} (NCCN), both obtained from axial sections, and D{sup mean3D} (Lung-RADS). Subsequently all diameter definitions were applied uniformly to all systems. Areas under the ROC curves (AUC) were used to evaluate risk discrimination. PanCan performed superiorly to Lung-RADS and NCCN (AUC 0.874 vs. 0.813, p = 0.003; 0.874 vs. 0.836, p = 0.010), using the original diameter specifications. When uniformly applying D{sup longest-C}, D{sup mean3D} and D{sup meanAxial}, PanCan remained superior to Lung-RADS (p < 0.001 - p = 0.001) and NCCN (p < 0.001 - p = 0.016). Diameter definition significantly influenced NCCN's performance with D{sup longest-C} being the worst (D{sup longest-C} vs. D{sup mean3D}, p = 0.005; D{sup longest-C} vs. D{sup meanAxial}, p = 0.016). Without follow-up information, the PanCan model performs significantly superiorly to Lung-RADS and the 1.2016 NCCN guidelines for discriminating benign from malignant nodules. The NCCN guidelines are most sensitive to nodule size definition. (orig.)

  1. TU-G-204-09: The Effects of Reduced- Dose Lung Cancer Screening CT On Lung Nodule Detection Using a CAD Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Young, S; Lo, P; Kim, G; Hsu, W; Hoffman, J; Brown, M; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2015-06-15

    Purpose: While Lung Cancer Screening CT is being performed at low doses, the purpose of this study was to investigate the effects of further reducing dose on the performance of a CAD nodule-detection algorithm. Methods: We selected 50 cases from our local database of National Lung Screening Trial (NLST) patients for which we had both the image series and the raw CT data from the original scans. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. 10 of the cases had at least one nodule reported on the NLST reader forms. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, the CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST reports. Subject-level mean sensitivities and false-positive rates were calculated for each dose level. Results: The mean sensitivities of the CAD algorithm were 35% at the original dose, 20% at 50% dose, and 42.5% at 25% dose. The false-positive rates, in decreasing-dose order, were 3.7, 2.9, and 10 per case. In certain cases, particularly in larger patients, there were severe photon-starvation artifacts, especially in the apical region due to the high-attenuating shoulders. Conclusion: The detection task was challenging for the CAD algorithm at all dose levels, including the original NLST dose. However, the false-positive rate at 25% dose approximately tripled, suggesting a loss of CAD robustness somewhere between 0.5 and 1.0 mGy. NCI grant U01 CA181156 (Quantitative Imaging Network); Tobacco Related Disease Research Project grant 22RT-0131.

  2. TU-G-204-09: The Effects of Reduced- Dose Lung Cancer Screening CT On Lung Nodule Detection Using a CAD Algorithm

    International Nuclear Information System (INIS)

    Young, S; Lo, P; Kim, G; Hsu, W; Hoffman, J; Brown, M; McNitt-Gray, M

    2015-01-01

    Purpose: While Lung Cancer Screening CT is being performed at low doses, the purpose of this study was to investigate the effects of further reducing dose on the performance of a CAD nodule-detection algorithm. Methods: We selected 50 cases from our local database of National Lung Screening Trial (NLST) patients for which we had both the image series and the raw CT data from the original scans. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. 10 of the cases had at least one nodule reported on the NLST reader forms. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, the CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST reports. Subject-level mean sensitivities and false-positive rates were calculated for each dose level. Results: The mean sensitivities of the CAD algorithm were 35% at the original dose, 20% at 50% dose, and 42.5% at 25% dose. The false-positive rates, in decreasing-dose order, were 3.7, 2.9, and 10 per case. In certain cases, particularly in larger patients, there were severe photon-starvation artifacts, especially in the apical region due to the high-attenuating shoulders. Conclusion: The detection task was challenging for the CAD algorithm at all dose levels, including the original NLST dose. However, the false-positive rate at 25% dose approximately tripled, suggesting a loss of CAD robustness somewhere between 0.5 and 1.0 mGy. NCI grant U01 CA181156 (Quantitative Imaging Network); Tobacco Related Disease Research Project grant 22RT-0131

  3. Novel high-resolution computed tomography-based radiomic classifier for screen-identified pulmonary nodules in the National Lung Screening Trial.

    Science.gov (United States)

    Peikert, Tobias; Duan, Fenghai; Rajagopalan, Srinivasan; Karwoski, Ronald A; Clay, Ryan; Robb, Richard A; Qin, Ziling; Sicks, JoRean; Bartholmai, Brian J; Maldonado, Fabien

    2018-01-01

    Optimization of the clinical management of screen-detected lung nodules is needed to avoid unnecessary diagnostic interventions. Herein we demonstrate the potential value of a novel radiomics-based approach for the classification of screen-detected indeterminate nodules. Independent quantitative variables assessing various radiologic nodule features such as sphericity, flatness, elongation, spiculation, lobulation and curvature were developed from the NLST dataset using 726 indeterminate nodules (all ≥ 7 mm, benign, n = 318 and malignant, n = 408). Multivariate analysis was performed using least absolute shrinkage and selection operator (LASSO) method for variable selection and regularization in order to enhance the prediction accuracy and interpretability of the multivariate model. The bootstrapping method was then applied for the internal validation and the optimism-corrected AUC was reported for the final model. Eight of the originally considered 57 quantitative radiologic features were selected by LASSO multivariate modeling. These 8 features include variables capturing Location: vertical location (Offset carina centroid z), Size: volume estimate (Minimum enclosing brick), Shape: flatness, Density: texture analysis (Score Indicative of Lesion/Lung Aggression/Abnormality (SILA) texture), and surface characteristics: surface complexity (Maximum shape index and Average shape index), and estimates of surface curvature (Average positive mean curvature and Minimum mean curvature), all with Pscreen-detected nodule characterization appears extremely promising however independent external validation is needed.

  4. Detection of small pulmonary nodules in high-field MR at 3 T: evaluation of different pulse sequences using porcine lung explants

    International Nuclear Information System (INIS)

    Regier, M.; Kaul, M.G.; Ittrich, H.; Bansmann, P.M.; Kemper, J.; Nolte-Ernsting, C.; Adam, G.; Kandel, S.; Hoffmann, B.; Heller, M.; Biederer, J.

    2007-01-01

    To evaluate two MR imaging sequences for the detection of artificial pulmonary nodules inside porcine lung explants. 67 agarose nodules ranging 3-20 mm were injected into ten porcine lungs within a dedicated chest phantom. The signal on T1-weighted images and radiopacity were adjusted by adding 0.125 mmol/l Gd-DTPA and 1.5 g/l of iodine. A T1-weighted three-dimensional gradient-echo (T1-3D-GRE; TR/TE:3.3/1.1 ms, slice:8 mm, flip-angle:10 ) and a T2-weighted half-Fourier fast-spin echo sequence (T2-HF-FSE; TR/TE:2000/66 ms, slice:7 mm, flip-angle:90 ) were applied in axial orientation using a 3-T system (Intera, Philips Medical Systems, Best, The Netherlands), followed by CT (16 x 0.5 mm) as reference. Nodule sizes and locations were assessed by three blinded observers. In nodules of >10 mm, sensitivity was 100% using 3D-GRE-MRI and 94% using the HF-FSE sequence. For nodules 6-10 mm, the sensitivity of MRI was lower than with CT (3D-GRE:92%; T2-HF-FSE:83%). In lesions smaller than 5 mm, the sensitivity declined to 80% (3D-GRE) and 53% (HF-FSE). Small lesion diameters were overestimated with both sequences, particularly with HF-FSE. This study confirms the feasibility of 3 T-MRI for lung nodule detection. In lesions greater than 5 mm, the sensitivity of the 3D-GRE sequence approximated CT (>90%), while sensitivity and PPV with the HF-FSE sequence were slightly inferior. (orig.)

  5. Clinical impact of abnormal FDG uptake in pulmonary nodules detected by CT in patients with only history of non-lung cancers

    International Nuclear Information System (INIS)

    Wong, C.O.; Nunez, R.; Welsh, R.J.; Chmielewski, G.W.; Hill, E.A.; Hill, J.C.; Ravikrishnan, K.P.; Darlene Fink-Bennett; Dworkin, H.J.

    2001-01-01

    Objective: The aim is to assess the clinical impact of positive FDG uptake in single (SPN) or multiple (MPN) pulmonary nodules detected by CT in patients with known past history of non-lung cancers (but no known lung cancers). Materials and Methods: Twenty-eight sequential patients with non-lung cancers (15 breast, 8 colon, 5 prostate) referred for evaluation of SPN or MPN by PET over a period of two years were included. F-18 FDG PET images, covering chest and upper abdomen, were interpreted blindly and then correlated with CT findings for the precise location of abnormal FDG uptake in the chest. Results: There was a significant number of abnormal FDG uptake in both SPN or MPN. Positive abnormal uptake suggestive of malignancy was found in 25% of patients in the form of SPN and 39% of patients in the form of MPN (p<0.03). Positive cases in the pattern of multiple foci of pulmonary uptake were attributed to metastatic disease. Otherwise positive cases were followed by tissue diagnosis and/or surgical attention. The negative cases were followed clinically. Of the 11 positive cases of MPN, 2 patients (18%) showed only abnormal FDG uptake in just one of the nodules, which was later confirmed at surgery to be a primary cancer of lung in both patients. Conclusion: These results suggest that PET scan would be just as useful in patients with SPN and known non-lung cancers as other patients with no history of any cancers. Not all patients with non-lung cancer and MPN have pulmonary metastasis by PET criteria. PET may single out a primary lung malignancy in patients with non-lung cancer and MPN. PET has thus great clinical impact in these patients with pulmonary nodules and known non-lung cancers as the management would otherwise be completely different in situations revealed by the study

  6. Localized thin-section CT with radiomics feature extraction and machine learning to classify early-detected pulmonary nodules from lung cancer screening

    Science.gov (United States)

    Tu, Shu-Ju; Wang, Chih-Wei; Pan, Kuang-Tse; Wu, Yi-Cheng; Wu, Chen-Te

    2018-03-01

    Lung cancer screening aims to detect small pulmonary nodules and decrease the mortality rate of those affected. However, studies from large-scale clinical trials of lung cancer screening have shown that the false-positive rate is high and positive predictive value is low. To address these problems, a technical approach is greatly needed for accurate malignancy differentiation among these early-detected nodules. We studied the clinical feasibility of an additional protocol of localized thin-section CT for further assessment on recalled patients from lung cancer screening tests. Our approach of localized thin-section CT was integrated with radiomics features extraction and machine learning classification which was supervised by pathological diagnosis. Localized thin-section CT images of 122 nodules were retrospectively reviewed and 374 radiomics features were extracted. In this study, 48 nodules were benign and 74 malignant. There were nine patients with multiple nodules and four with synchronous multiple malignant nodules. Different machine learning classifiers with a stratified ten-fold cross-validation were used and repeated 100 times to evaluate classification accuracy. Of the image features extracted from the thin-section CT images, 238 (64%) were useful in differentiating between benign and malignant nodules. These useful features include CT density (p  =  0.002 518), sigma (p  =  0.002 781), uniformity (p  =  0.032 41), and entropy (p  =  0.006 685). The highest classification accuracy was 79% by the logistic classifier. The performance metrics of this logistic classification model was 0.80 for the positive predictive value, 0.36 for the false-positive rate, and 0.80 for the area under the receiver operating characteristic curve. Our approach of direct risk classification supervised by the pathological diagnosis with localized thin-section CT and radiomics feature extraction may support clinical physicians in determining

  7. Development and evaluation of a computer-aided diagnostic scheme for lung nodule detection in chest radiographs by means of two-stage nodule enhancement with support vector classification

    International Nuclear Information System (INIS)

    Chen Sheng; Suzuki, Kenji; MacMahon, Heber

    2011-01-01

    Purpose: To develop a computer-aided detection (CADe) scheme for nodules in chest radiographs (CXRs) with a high sensitivity and a low false-positive (FP) rate. Methods: The authors developed a CADe scheme consisting of five major steps, which were developed for improving the overall performance of CADe schemes. First, to segment the lung fields accurately, the authors developed a multisegment active shape model. Then, a two-stage nodule-enhancement technique was developed for improving the conspicuity of nodules. Initial nodule candidates were detected and segmented by using the clustering watershed algorithm. Thirty-one shape-, gray-level-, surface-, and gradient-based features were extracted from each segmented candidate for determining the feature space, including one of the new features based on the Canny edge detector to eliminate a major FP source caused by rib crossings. Finally, a nonlinear support vector machine (SVM) with a Gaussian kernel was employed for classification of the nodule candidates. Results: To evaluate and compare the scheme to other published CADe schemes, the authors used a publicly available database containing 140 nodules in 140 CXRs and 93 normal CXRs. The CADe scheme based on the SVM classifier achieved sensitivities of 78.6% (110/140) and 71.4% (100/140) with averages of 5.0 (1165/233) FPs/image and 2.0 (466/233) FPs/image, respectively, in a leave-one-out cross-validation test, whereas the CADe scheme based on a linear discriminant analysis classifier had a sensitivity of 60.7% (85/140) at an FP rate of 5.0 FPs/image. For nodules classified as ''very subtle'' and ''extremely subtle,'' a sensitivity of 57.1% (24/42) was achieved at an FP rate of 5.0 FPs/image. When the authors used a database developed at the University of Chicago, the sensitivities was 83.3% (40/48) and 77.1% (37/48) at an FP rate of 5.0 (240/48) FPs/image and 2.0 (96/48) FPs /image, respectively. Conclusions: These results compare favorably to those described for

  8. Seven-microRNA panel for lung adenocarcinoma early diagnosis in patients presenting with ground-glass nodules

    Directory of Open Access Journals (Sweden)

    He Y

    2017-12-01

    Full Text Available Yayi He,1,2,* Yang Yang,3,* Peng Kuang,1 Shengxiang Ren,1 Leslie Rozeboom,2 Christopher J Rivard,2 Xuefei Li,4 Caicun Zhou,1 Fred R Hirsch2 1Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, People’s Republic of China; 2Division of Medical Oncology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; 3Department of Surgery, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, 4Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: MicroRNA (miRNA expression is correlated with tumor histology, differentiation, invasiveness and treatment outcome. We aimed to identify miRNAs whose differential expression might enable early diagnosis of lung adenocarcinoma in patients presenting with ground-glass nodules (GGNs.Methods: To identify potential miRNAs of interest, we analyzed the miRNA expression profile of tumor and adjacent non-para-tumor tissue in three participants by next-generation sequencing (NGS. We then assessed the expression levels of the miRNAs of interest in 73 lung adenocarcinomas presenting with GGNs with matched adjacent non-tumor tissue by quantitative real-time polymerase chain reaction (qRT-PCR. We also detected the miRNA panel in 66 lung benign diseases and 66 lung adenocarcinomas presenting with GGN lesion tissues by qRT-PCR. Target genes of our selected miRNA panel were predicted using Miranda with default parameters.Results: Twenty-three miRNAs showed differential expression between tumor and adjacent non-tumor tissue by NGS. Five miRNAs exhibited higher expression in tumor tissue compared to adjacent non-tumor tissue (P

  9. A comparison of six software packages for evaluation of solid lung nodules using semi-automated volumetry: What is the minimum increase in size to detect growth in repeated CT examinations

    International Nuclear Information System (INIS)

    Hoop, Bartjan de; Gietema, Hester; Prokop, Mathias; Ginneken, Bram van; Zanen, Pieter; Groenewegen, Gerard

    2009-01-01

    We compared interexamination variability of CT lung nodule volumetry with six currently available semi-automated software packages to determine the minimum change needed to detect the growth of solid lung nodules. We had ethics committee approval. To simulate a follow-up examination with zero growth, we performed two low-dose unenhanced CT scans in 20 patients referred for pulmonary metastases. Between examinations, patients got off and on the table. Volumes of all pulmonary nodules were determined on both examinations using six nodule evaluation software packages. Variability (upper limit of the 95% confidence interval of the Bland-Altman plot) was calculated for nodules for which segmentation was visually rated as adequate. We evaluated 214 nodules (mean diameter 10.9 mm, range 3.3 mm-30.0 mm). Software packages provided adequate segmentation in 71% to 86% of nodules (p < 0.001). In case of adequate segmentation, variability in volumetry between scans ranged from 16.4% to 22.3% for the various software packages. Variability with five to six software packages was significantly less for nodules ≥8 mm in diameter (range 12.9%-17.1%) than for nodules <8 mm (range 18.5%-25.6%). Segmented volumes of each package were compared to each of the other packages. Systematic volume differences were detected in 11/15 comparisons. This hampers comparison of nodule volumes between software packages. (orig.)

  10. Computer-aided detection of lung nodules on multidetector CT in concurrent-reader and second-reader modes: A comparative study

    International Nuclear Information System (INIS)

    Matsumoto, Sumiaki; Ohno, Yoshiharu; Aoki, Takatoshi; Yamagata, Hitoshi; Nogami, Munenobu; Matsumoto, Keiko; Yamashita, Yoshiko; Sugimura, Kazuro

    2013-01-01

    Purpose: To compare the reading times and detection performances of radiologists in concurrent-reader and second-reader modes of computer-aided detection (CAD) for lung nodules on multidetector computed tomography (CT). Materials and Methods: Fifty clinical multidetector CT datasets containing nodules up to 20 mm in diameter were retrospectively collected. For the detection and rating of non-calcified nodules larger than 4 mm in diameter, 6 radiologists (3 experienced radiologists and 3 resident radiologists) independently interpreted these datasets twice, once with concurrent-reader CAD and once with second-reader CAD. The reference standard of nodules in the datasets was determined by the consensus of two experienced chest radiologists. The reading times and detection performances in the two modes of CAD were statistically compared, where jackknife free-response receiver operating characteristic (JAFROC) analysis was used for the comparison of detection performances. Results: Two hundreds and seven nodules constituted the reference standard. Reading time was significantly shorter in the concurrent-reader mode than in the second-reader mode, with the mean reading time for the 6 radiologists being 132 s with concurrent-reader CAD and 210 s with second-reader CAD (p < 0.01). JAFROC analysis revealed no significant difference between the detection performances in the two modes, with the average figure-of-merit value for the 6 radiologists being 0.70 with concurrent-reader CAD and 0.72 with second-reader CAD (p = 0.35). Conclusion: In CAD for lung nodules on multidetector CT, the concurrent-reader mode is more time-efficient than the second-reader mode, and there can be no significant difference between the two modes in terms of detection performance of radiologists

  11. Computer-aided detection (CAD) of lung nodules in CT scans: radiologist performance and reading time with incremental CAD assistance

    International Nuclear Information System (INIS)

    Roos, Justus E.; Paik, David; Olsen, David; Liu, Emily G.; Leung, Ann N.; Mindelzun, Robert; Choudhury, Kingshuk R.; Napel, Sandy; Rubin, Geoffrey D.; Chow, Lawrence C.; Naidich, David P.

    2010-01-01

    The diagnostic performance of radiologists using incremental CAD assistance for lung nodule detection on CT and their temporal variation in performance during CAD evaluation was assessed. CAD was applied to 20 chest multidetector-row computed tomography (MDCT) scans containing 190 non-calcified ≥3-mm nodules. After free search, three radiologists independently evaluated a maximum of up to 50 CAD detections/patient. Multiple free-response ROC curves were generated for free search and successive CAD evaluation, by incrementally adding CAD detections one at a time to the radiologists' performance. The sensitivity for free search was 53% (range, 44%-59%) at 1.15 false positives (FP)/patient and increased with CAD to 69% (range, 59-82%) at 1.45 FP/patient. CAD evaluation initially resulted in a sharp rise in sensitivity of 14% with a minimal increase in FP over a time period of 100 s, followed by flattening of the sensitivity increase to only 2%. This transition resulted from a greater prevalence of true positive (TP) versus FP detections at early CAD evaluation and not by a temporal change in readers' performance. The time spent for TP (9.5 s ± 4.5 s) and false negative (FN) (8.4 s ± 6.7 s) detections was similar; FP decisions took two- to three-times longer (14.4 s ± 8.7 s) than true negative (TN) decisions (4.7 s ± 1.3 s). When CAD output is ordered by CAD score, an initial period of rapid performance improvement slows significantly over time because of non-uniformity in the distribution of TP CAD output and not to a changing reader performance over time. (orig.)

  12. Role of -FDG PET Scan in Rheumatoid Lung Nodule: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Christine L. Chhakchhuak

    2013-01-01

    Full Text Available Flourine-18 fluoro-2-deoxy-glucose (18F-FDG positron emission tomography combined with computed tomography (PET/CT is a useful test for the management of malignant conditions. Inflammatory and infectious processes, however, can cause increased uptake on PET scanning, often causing diagnostic dilemmas. This knowledge is important to the rheumatologist not only because of the inflammatory conditions we treat but also because certain rheumatic diseases impose an increased risk of malignancy either due to the disease itself or as a consequence of medications used to treat the rheumatic diseases. There is an increasing body of evidence investigating the role of PET scans in inflammatory conditions. This paper describes a patient with rheumatoid arthritis who developed pulmonary nodules that showed increased uptake on PET/CT scan and reviews the use of PET scanning in the diagnosis and management of rheumatoid arthritis.

  13. Interobserver-variability of lung nodule volumetry considering different segmentation algorithms and observer training levels

    International Nuclear Information System (INIS)

    Bolte, H.; Jahnke, T.; Schaefer, F.K.W.; Wenke, R.; Hoffmann, B.; Freitag-Wolf, S.; Dicken, V.; Kuhnigk, J.M.; Lohmann, J.; Voss, S.; Knoess, N.

    2007-01-01

    Objective: The aim of this study was to investigate the interobserver variability of CT based diameter and volumetric measurements of artificial pulmonary nodules. A special interest was the consideration of different measurement methods, observer experience and training levels. Materials and methods: For this purpose 46 artificial small solid nodules were examined in a dedicated ex-vivo chest phantom with multislice-spiral CT (20 mAs, 120 kV, collimation 16 mm x 0.75 mm, table feed 15 mm, reconstructed slice thickness 1 mm, reconstruction increment 0.7 mm, intermediate reconstruction kernel). Two observer groups of different radiologic experience (0 and more than 5 years of training, 3 observers each) analysed all lesions with digital callipers and 2 volumetry software packages (click-point depending and robust volumetry) in a semi-automatic and manually corrected mode. For data analysis the variation coefficient (VC) was calculated in per cent for each group and a Wilcoxon test was used for analytic statistics. Results: Click-point robust volumetry showed with a VC of <0.01% in both groups the smallest interobserver variability. Between experienced and un-experienced observers interobserver variability was significantly different for diameter measurements (p = 0.023) but not for semi-automatic and manual corrected volumetry. A significant training effect was revealed for diameter measurements (p = 0.003) and semi-automatic measurements of click-point depending volumetry (p = 0.007) in the un-experienced observer group. Conclusions: Compared to diameter measurements volumetry achieves a significantly smaller interobserver variance and advanced volumetry algorithms are independent of observer experience

  14. Computer-aided detection of artificial pulmonary nodules using an ex vivo lung phantom: influence of exposure parameters and iterative reconstruction.

    Science.gov (United States)

    Wielpütz, Mark O; Wroblewski, Jacek; Lederlin, Mathieu; Dinkel, Julien; Eichinger, Monika; Koenigkam-Santos, M; Biederer, Jürgen; Kauczor, Hans-Ulrich; Puderbach, Michael U; Jobst, Bertram J

    2015-05-01

    To evaluate the influence of exposure parameters and raw-data based iterative reconstruction (IR) on the performance of computer-aided detection (CAD) of pulmonary nodules on chest multidetector computed tomography (MDCT). Seven porcine lung explants were inflated in a dedicated ex vivo phantom shell and prepared with n=162 artificial nodules of a clinically relevant volume and maximum diameter (46-1063 μl, and 6.2-21.5 mm). n=118 nodules were solid and n=44 part-solid. MDCT was performed with different combinations of 120 and 80 kV with 120, 60, 30 and 12 mA*s, and reconstructed with both filtered back projection (FBP) and IR. Subsequently, 16 datasets per lung were subjected to dedicated CAD software. The rate of true positive, false negative and false positive CAD marks was measured for each reconstruction. The rate of true positive findings ranged between 88.9-91.4% for FBP and 88.3-90.1% for IR (n.s.) with most exposure settings, but was significantly lower with the combination of 80 kV and 12 mA*s (80.9% and 81.5%, respectively, pvolumes 300 μl (p<0.05). Similarly, it was significantly lower for diameters <12 mm compared to ≥12 mm (p<0.05). The rate of true positives for solid and part-solid nodules was similar. Nodule CAD on chest MDCT is robust over a wide range of exposure settings. Noise reduction by IR is not detrimental for CAD, and may be used to improve image quality in the setting of low-dose MDCT for lung cancer screening. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Assessing the use of digital radiography and a real-time interactive pulmonary nodule analysis system for large population lung cancer screening

    International Nuclear Information System (INIS)

    Xu Yan; Ma Daqing; He Wen

    2012-01-01

    Rationale and objectives: To assess the use of chest digital radiograph (DR) assisted with a real-time interactive pulmonary nodule analysis system in large population lung cancer screening. Materials and methods: 346 DR/CR patient studies with corresponding CT images were selected from 12,500 patients screened for lung cancer from year 2007 to 2009. Two expert chest radiologists established CT-confirmed Gold Standard of nodules on DR/CR images with consensus. These cases were read by eight other chest radiologists (participating radiologists) first without using a real-time interactive pulmonary nodule analysis system and then re-read using the system. Performances of participating radiologists and the computer system were analyzed. Results: The computer system achieved similar performance on DR and CR images, with a detection rate of 76% and an average FPs of 2.0 per image. Before and after using the computer-aided detection system, the nodule detection sensitivities of the participating radiologists were 62.3% and 77.3% respectively, and the A z values increased from 0.794 to 0.831. Statistical analysis demonstrated statically significant improvement for the participating radiologists after using the computer analysis system with a P-value 0.05. Conclusion: The computer system could help radiologists identify more lesions, especially small ones that are more likely to be overlooked on chest DR/CR images, and could help reduce inter-observer diagnostic variations, while its FPs were easy to recognize and dismiss. It is suggested that DR/CR assisted by the real-time interactive pulmonary nodule analysis system may be an effective means to screen large populations for lung cancer.

  16. Nodule management protocol of the NELSON randomised lung cancer screening trial

    NARCIS (Netherlands)

    Xu, Dong Ming; Gietema, Hester; de Koning, Harry; Vernhout, Rene; Nackaerts, Kristiaan; Prokop, Mathias; Weenink, Carla; Lammers, Jan-Willem; Groen, Harry; Oudkerk, Matthijs; van Klaveren, Rob

    In December 2003, the Dutch-Belgian NELSON trial, a Dutch acronym for "Nederlands-Leuvens Longkanker Screenings ONderzoek", has been launched. Primary objective of the NELSON trial is to investigate whether screening for lung cancer by 16-detector multi-slice CT with 16 mm x 0.75 mm collimation and

  17. Computer-aided diagnostic scheme for the detection of lung nodules on chest radiographs: Localized search method based on anatomical classification

    International Nuclear Information System (INIS)

    Shiraishi, Junji; Li Qiang; Suzuki, Kenji; Engelmann, Roger; Doi, Kunio

    2006-01-01

    We developed an advanced computer-aided diagnostic (CAD) scheme for the detection of various types of lung nodules on chest radiographs intended for implementation in clinical situations. We used 924 digitized chest images (992 noncalcified nodules) which had a 500x500 matrix size with a 1024 gray scale. The images were divided randomly into two sets which were used for training and testing of the computerized scheme. In this scheme, the lung field was first segmented by use of a ribcage detection technique, and then a large search area (448x448 matrix size) within the chest image was automatically determined by taking into account the locations of a midline and a top edge of the segmented ribcage. In order to detect lung nodule candidates based on a localized search method, we divided the entire search area into 7x7 regions of interest (ROIs: 64x64 matrix size). In the next step, each ROI was classified anatomically into apical, peripheral, hilar, and diaphragm/heart regions by use of its image features. Identification of lung nodule candidates and extraction of image features were applied for each localized region (128x128 matrix size), each having its central part (64x64 matrix size) located at a position corresponding to a ROI that was classified anatomically in the previous step. Initial candidates were identified by use of the nodule-enhanced image obtained with the average radial-gradient filtering technique, in which the filter size was varied adaptively depending on the location and the anatomical classification of the ROI. We extracted 57 image features from the original and nodule-enhanced images based on geometric, gray-level, background structure, and edge-gradient features. In addition, 14 image features were obtained from the corresponding locations in the contralateral subtraction image. A total of 71 image features were employed for three sequential artificial neural networks (ANNs) in order to reduce the number of false-positive candidates. All

  18. Optimal dose levels in screening chest CT for unimpaired detection and volumetry of lung nodules, with and without computer assisted detection at minimal patient radiation.

    Directory of Open Access Journals (Sweden)

    Andreas Christe

    Full Text Available OBJECTIVES: The aim of this phantom study was to minimize the radiation dose by finding the best combination of low tube current and low voltage that would result in accurate volume measurements when compared to standard CT imaging without significantly decreasing the sensitivity of detecting lung nodules both with and without the assistance of CAD. METHODS: An anthropomorphic chest phantom containing artificial solid and ground glass nodules (GGNs, 5-12 mm was examined with a 64-row multi-detector CT scanner with three tube currents of 100, 50 and 25 mAs in combination with three tube voltages of 120, 100 and 80 kVp. This resulted in eight different protocols that were then compared to standard CT sensitivity (100 mAs/120 kVp. For each protocol, at least 127 different nodules were scanned in 21-25 phantoms. The nodules were analyzed in two separate sessions by three independent, blinded radiologists and computer-aided detection (CAD software. RESULTS: The mean sensitivity of the radiologists for identifying solid lung nodules on a standard CT was 89.7% ± 4.9%. The sensitivity was not significantly impaired when the tube and current voltage were lowered at the same time, except at the lowest exposure level of 25 mAs/80 kVp [80.6% ± 4.3% (p = 0.031]. Compared to the standard CT, the sensitivity for detecting GGNs was significantly lower at all dose levels when the voltage was 80 kVp; this result was independent of the tube current. The CAD significantly increased the radiologists' sensitivity for detecting solid nodules at all dose levels (5-11%. No significant volume measurement errors (VMEs were documented for the radiologists or the CAD software at any dose level. CONCLUSIONS: Our results suggest a CT protocol with 25 mAs and 100 kVp is optimal for detecting solid and ground glass nodules in lung cancer screening. The use of CAD software is highly recommended at all dose levels.

  19. 3D Convolutional Neural Network for Automatic Detection of Lung Nodules in Chest CT.

    Science.gov (United States)

    Hamidian, Sardar; Sahiner, Berkman; Petrick, Nicholas; Pezeshk, Aria

    2017-01-01

    Deep convolutional neural networks (CNNs) form the backbone of many state-of-the-art computer vision systems for classification and segmentation of 2D images. The same principles and architectures can be extended to three dimensions to obtain 3D CNNs that are suitable for volumetric data such as CT scans. In this work, we train a 3D CNN for automatic detection of pulmonary nodules in chest CT images using volumes of interest extracted from the LIDC dataset. We then convert the 3D CNN which has a fixed field of view to a 3D fully convolutional network (FCN) which can generate the score map for the entire volume efficiently in a single pass. Compared to the sliding window approach for applying a CNN across the entire input volume, the FCN leads to a nearly 800-fold speed-up, and thereby fast generation of output scores for a single case. This screening FCN is used to generate difficult negative examples that are used to train a new discriminant CNN. The overall system consists of the screening FCN for fast generation of candidate regions of interest, followed by the discrimination CNN.

  20. Thoracoscopic anatomical lung segmentectomy using 3D computed tomography simulation without tumour markings for non-palpable and non-visualized small lung nodules.

    Science.gov (United States)

    Kato, Hirohisa; Oizumi, Hiroyuki; Suzuki, Jun; Hamada, Akira; Watarai, Hikaru; Sadahiro, Mitsuaki

    2017-09-01

    Although wedge resection can be curative for small lung tumours, tumour marking is sometimes required for resection of non-palpable or visually undetectable lung nodules as a method for identification of tumours. Tumour marking sometimes fails and occasionally causes serious complications. We have performed many thoracoscopic segmentectomies using 3D computed tomography simulation for undetectable small lung tumours without any tumour markings. The aim of this study was to investigate whether thoracoscopic segmentectomy planned with 3D computed tomography simulation could precisely remove non-palpable and visually undetectable tumours. Between January 2012 and March 2016, 58 patients underwent thoracoscopic segmentectomy using 3D computed tomography simulation for non-palpable, visually undetectable tumours. Surgical outcomes were evaluated. A total of 35, 14 and 9 patients underwent segmentectomy, subsegmentectomy and segmentectomy combined with adjacent subsegmentectomy, respectively. All tumours were correctly resected without tumour marking. The median tumour size and distance from the visceral pleura was 14 ± 5.2 mm (range 5-27 mm) and 11.6 mm (range 1-38.8 mm), respectively. Median values related to the procedures were operative time, 176 min (range 83-370 min); blood loss, 43 ml (range 0-419 ml); duration of chest tube placement, 1 day (range 1-8 days); and postoperative hospital stay, 5 days (range 3-12 days). Two cases were converted to open thoracotomy due to bleeding. Three cases required pleurodesis for pleural fistula. No recurrences occurred during the mean follow-up period of 44.4 months (range 5-53 months). Thoracoscopic segmentectomy using 3D computed tomography simulation was feasible and could be performed to resect undetectable tumours with no tumour markings. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  1. Development of a Blood-Based Biomarker Panel for Indeterminate Lung Nodules

    Science.gov (United States)

    2016-09-01

    based markers are a promising and attractive approach to complement LDCT because of the potential to identify those subjects that need to undergo further...concerns including high false positivity, cost, and radiation exposure. Blood- based markers are a promising and attractive approach to complement...innovations, successes, or any change in practice or behavior that has come about as a result of the project Although a large number of lung cancer biomarker

  2. A 3-D Riesz-Covariance Texture Model for Prediction of Nodule Recurrence in Lung CT

    OpenAIRE

    Cirujeda Pol; Dicente Cid Yashin; Müller Henning; Rubin Daniel L.; Aguilera Todd A.; Jr. Billy W. Loo; Diehn Maximilian; Binefa Xavier; Depeursinge Adrien

    2016-01-01

    This paper proposes a novel imaging biomarker of lung cancer relapse from 3 D texture analysis of CT images. Three dimensional morphological nodular tissue properties are described in terms of 3 D Riesz wavelets. The responses of the latter are aggregated within nodular regions by means of feature covariances which leverage rich intra and inter variations of the feature space dimensions. When compared to the classical use of the average for feature aggregation feature covariances preserve sp...

  3. Spatial frequency characteristics at image decision-point locations for observers with different radiological backgrounds in lung nodule detection

    Science.gov (United States)

    Pietrzyk, Mariusz W.; Manning, David J.; Dix, Alan; Donovan, Tim

    2009-02-01

    Aim: The goal of the study is to determine the spatial frequency characteristics at locations in the image of overt and covert observers' decisions and find out if there are any similarities in different observers' groups: the same radiological experience group or the same accuracy scored level. Background: The radiological task is described as a visual searching decision making procedure involving visual perception and cognitive processing. Humans perceive the world through a number of spatial frequency channels, each sensitive to visual information carried by different spatial frequency ranges and orientations. Recent studies have shown that particular physical properties of local and global image-based elements are correlated with the performance and the level of experience of human observers in breast cancer and lung nodule detections. Neurological findings in visual perception were an inspiration for wavelet applications in vision research because the methodology tries to mimic the brain processing algorithms. Methods: The wavelet approach to the set of postero-anterior chest radiographs analysis has been used to characterize perceptual preferences observers with different levels of experience in the radiological task. Psychophysical methodology has been applied to track eye movements over the image, where particular ROIs related to the observers' fixation clusters has been analysed in the spaces frame by Daubechies functions. Results: Significance differences have been found between the spatial frequency characteristics at the location of different decisions.

  4. TH-AB-207A-09: Tailoring TCM Schemes to a Task: Evaluating the Impact of Customized TCM Profiles On Detection of Lung Nodules in Simulated CT Lung Cancer Screening

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, J; McNitt-Gray, M [Departments of Biomedical Physics and Radiology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Noo, F [University of Utah, Salt Lake City, UT (United States); Young, S [Department of Radiology, UCLA, Los Angeles, CA (United States)

    2016-06-15

    Purpose: Recent work has shown that current TCM profile designs boost detection of low-contrast lung lesions in the lung apices, but yield reduced detection performance in the mid and lower lung regions relative to fixed tube current cases. This observed imbalance suggests that the TCM scheme might be tailored in new ways to maximize nodule detection throughout the entire lung. In this work, we begin a preliminary investigation into custom TCM profiles in an attempt to achieve uniform lesion detection throughout the extent of the lung. Methods: Low-contrast (25HU), 6mm nodules representing ground glass opacities were simulated at 1mm intervals over the length the lungs in a voxelized model of the XCAT phantom, one nodule per lung, per simulated scan. Voxel values represented attenuation values at 80keV. CT projection data was created by simulating a finite focal spot and using Joseph’s method for forward projection; scanner geometry was that of the Siemens Sensation 64 and the X-ray source was simulated as an 80keV monochromatic beam. Noise realizations were created using Poisson statistics, a realistic bowtie filter and varying tube current. 500 noise realizations were created for the custom TCM designs. All reconstruction was done with FreeCT-wFBP. An SKE/BKE task was used in conjunction with a 2D Hotelling Observer to calculate area-under-the-curve (AUC) as a proxy for “detectability.” AUC was plotted as a function of nodule Z-location to create a “detectability map.” The detectability map for the custom TCM curve was qualitatively assessed relative to previous results for the fixed TC and clinical TCM cases for uniformity. Results: Detection uniformity was improved throughout the mid and lower lungs, however detection remained disproportionately high in the upper lung region. Conclusion: Detection uniformity was improved with a custom TC profile. Future work will incorporate an analytic, task-specific approach to optimize the TC scheme for nodule

  5. TH-AB-207A-09: Tailoring TCM Schemes to a Task: Evaluating the Impact of Customized TCM Profiles On Detection of Lung Nodules in Simulated CT Lung Cancer Screening

    International Nuclear Information System (INIS)

    Hoffman, J; McNitt-Gray, M; Noo, F; Young, S

    2016-01-01

    Purpose: Recent work has shown that current TCM profile designs boost detection of low-contrast lung lesions in the lung apices, but yield reduced detection performance in the mid and lower lung regions relative to fixed tube current cases. This observed imbalance suggests that the TCM scheme might be tailored in new ways to maximize nodule detection throughout the entire lung. In this work, we begin a preliminary investigation into custom TCM profiles in an attempt to achieve uniform lesion detection throughout the extent of the lung. Methods: Low-contrast (25HU), 6mm nodules representing ground glass opacities were simulated at 1mm intervals over the length the lungs in a voxelized model of the XCAT phantom, one nodule per lung, per simulated scan. Voxel values represented attenuation values at 80keV. CT projection data was created by simulating a finite focal spot and using Joseph’s method for forward projection; scanner geometry was that of the Siemens Sensation 64 and the X-ray source was simulated as an 80keV monochromatic beam. Noise realizations were created using Poisson statistics, a realistic bowtie filter and varying tube current. 500 noise realizations were created for the custom TCM designs. All reconstruction was done with FreeCT_wFBP. An SKE/BKE task was used in conjunction with a 2D Hotelling Observer to calculate area-under-the-curve (AUC) as a proxy for “detectability.” AUC was plotted as a function of nodule Z-location to create a “detectability map.” The detectability map for the custom TCM curve was qualitatively assessed relative to previous results for the fixed TC and clinical TCM cases for uniformity. Results: Detection uniformity was improved throughout the mid and lower lungs, however detection remained disproportionately high in the upper lung region. Conclusion: Detection uniformity was improved with a custom TC profile. Future work will incorporate an analytic, task-specific approach to optimize the TC scheme for nodule

  6. Development of a multivariate model to predict the likelihood of carcinoma in patients with indeterminate peripheral lung nodules after a nondiagnostic bronchoscopic evaluation.

    Science.gov (United States)

    Voss, Jesse S; Iqbal, Seher; Jenkins, Sarah M; Henry, Michael R; Clayton, Amy C; Jett, James R; Kipp, Benjamin R; Halling, Kevin C; Maldonado, Fabien

    2014-01-01

    Studies have shown that fluorescence in situ hybridization (FISH) testing increases lung cancer detection on cytology specimens in peripheral nodules. The goal of this study was to determine whether a predictive model using clinical features and routine cytology with FISH results could predict lung malignancy after a nondiagnostic bronchoscopic evaluation. Patients with an indeterminate peripheral lung nodule that had a nondiagnostic bronchoscopic evaluation were included in this study (N = 220). FISH was performed on residual bronchial brushing cytology specimens diagnosed as negative (n = 195), atypical (n = 16), or suspicious (n = 9). FISH results included hypertetrasomy (n = 30) and negative (n = 190). Primary study end points included lung cancer status along with time to diagnosis of lung cancer or date of last clinical follow-up. Hazard ratios (HRs) were calculated using Cox proportional hazards regression model analyses, and P values < .05 were considered statistically significant. The mean age of the 220 patients was 66.7 years (range, 35-91), and most (58%) were men. Most patients (79%) were current or former smokers with a mean pack year history of 43.2 years (median, 40; range, 1-200). After multivariate analysis, hypertetrasomy FISH (HR = 2.96, P < .001), pack years (HR = 1.03 per pack year up to 50, P = .001), age (HR = 1.04 per year, P = .02), atypical or suspicious cytology (HR = 2.02, P = .04), and nodule spiculation (HR = 2.36, P = .003) were independent predictors of malignancy over time and were used to create a prediction model (C-statistic = 0.78). These results suggest that this multivariate model including test results and clinical features may be useful following a nondiagnostic bronchoscopic examination. © 2013.

  7. Computed tomography of pulmonary nodules

    International Nuclear Information System (INIS)

    Nakata, Hajime; Honda, Hiroshi; Nakayama, Chikashi; Kimoto, Tatsuya; Nakayama, Takashi

    1983-01-01

    We have evaluated the value of computed tomography (CT) in distinguishing benign and malignant pulmonary nodules. CT was performed on 30 cases of solitary pulmonary nodules consisting of 17 primary lung cancers, 3 metastatic tumors and 10 benign nodules. The CT number was calculated for each lesion. Three benign nodules showed CT numbers well above the range of malignant nodules, and only in one of them was calcification visible on conventional tomography. In 6 benign nodules, the CT numbers overlapped those of malignant lesion and could not be differentiated. Thus the measurement of CT number can be useful to confirm the benign nature of certain nodules when calcification is unclear or not visible on conventional tomography. As for the morphological observation of the nodule, CT was not superior to conventional tomography and its value seems to be limited. (author)

  8. High-resolution computed tomography findings of pulmonary tuberculosis in lung transplant recipients

    Directory of Open Access Journals (Sweden)

    Irai Luis Giacomelli

    Full Text Available ABSTRACT Objective: Respiratory infections constitute a major cause of morbidity and mortality in solid organ transplant recipients. The incidence of pulmonary tuberculosis is high among such patients. On imaging, tuberculosis has various presentations. Greater understanding of those presentations could reduce the impact of the disease by facilitating early diagnosis. Therefore, we attempted to describe the HRCT patterns of pulmonary tuberculosis in lung transplant recipients. Methods: From two hospitals in southern Brazil, we collected the following data on lung transplant recipients who developed pulmonary tuberculosis: gender; age; symptoms; the lung disease that led to transplantation; HRCT pattern; distribution of findings; time from transplantation to pulmonary tuberculosis; and mortality rate. The HRCT findings were classified as miliary nodules; cavitation and centrilobular nodules with a tree-in-bud pattern; ground-glass attenuation with consolidation; mediastinal lymph node enlargement; or pleural effusion. Results: We evaluated 402 lung transplant recipients, 19 of whom developed pulmonary tuberculosis after transplantation. Among those 19 patients, the most common HRCT patterns were ground-glass attenuation with consolidation (in 42%; cavitation and centrilobular nodules with a tree-in-bud pattern (in 31.5%; and mediastinal lymph node enlargement (in 15.7%. Among the patients with cavitation and centrilobular nodules with a tree-in-bud pattern, the distribution was within the upper lobes in 66.6%. No pleural effusion was observed. Despite treatment, one-year mortality was 47.3%. Conclusions: The predominant HRCT pattern was ground-glass attenuation with consolidation, followed by cavitation and centrilobular nodules with a tree-in-bud pattern. These findings are similar to those reported for immunocompetent patients with pulmonary tuberculosis and considerably different from those reported for AIDS patients with the same disease.

  9. High-resolution computed tomography findings of pulmonary tuberculosis in lung transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Giacomelli, Irai Luis; Schuhmacher Neto, Roberto; Nin, Carlos Schuller; Cassano, Priscilla de Souza; Pereira, Marisa; Moreira, Jose da Silva; Nascimento, Douglas Zaione; Hochhegger, Bruno, E-mail: iraigiacomelli@gmail.com [Complexo Hospitalar Santa Casa de Porto Alegre, RS (Brazil)

    2017-07-15

    Objective: Respiratory infections constitute a major cause of morbidity and mortality in solid organ transplant recipients. The incidence of pulmonary tuberculosis is high among such patients. On imaging, tuberculosis has various presentations. Greater understanding of those presentations could reduce the impact of the disease by facilitating early diagnosis. Therefore, we attempted to describe the HRCT patterns of pulmonary tuberculosis in lung transplant recipients. Methods: From two hospitals in southern Brazil, we collected the following data on lung transplant recipients who developed pulmonary tuberculosis: gender; age; symptoms; the lung disease that led to transplantation; HRCT pattern; distribution of findings; time from transplantation to pulmonary tuberculosis; and mortality rate. The HRCT findings were classified as miliary nodules; cavitation and centrilobular nodules with a tree-in-bud pattern; ground-glass attenuation with consolidation; mediastinal lymph node enlargement; or pleural effusion. Results: We evaluated 402 lung transplant recipients, 19 of whom developed pulmonary tuberculosis after transplantation. Among those 19 patients, the most common HRCT patterns were ground-glass attenuation with consolidation (in 42%); cavitation and centrilobular nodules with a tree-in-bud pattern (in 31.5%); and mediastinal lymph node enlargement (in 15.7%). Among the patients with cavitation and centrilobular nodules with a tree-in-bud pattern, the distribution was within the upper lobes in 66.6%. No pleural effusion was observed. Despite treatment, one-year mortality was 47.3%. Conclusions: The predominant HRCT pattern was ground-glass attenuation with consolidation, followed by cavitation and centrilobular nodules with a tree-in-bud pattern. These findings are similar to those reported for immunocompetent patients with pulmonary tuberculosis and considerably different from those reported for AIDS patients with the same disease. (author)

  10. High-resolution computed tomography findings of pulmonary tuberculosis in lung transplant recipients.

    Science.gov (United States)

    Giacomelli, Irai Luis; Schuhmacher Neto, Roberto; Nin, Carlos Schuller; Cassano, Priscilla de Souza; Pereira, Marisa; Moreira, José da Silva; Nascimento, Douglas Zaione; Hochhegger, Bruno

    2017-01-01

    Respiratory infections constitute a major cause of morbidity and mortality in solid organ transplant recipients. The incidence of pulmonary tuberculosis is high among such patients. On imaging, tuberculosis has various presentations. Greater understanding of those presentations could reduce the impact of the disease by facilitating early diagnosis. Therefore, we attempted to describe the HRCT patterns of pulmonary tuberculosis in lung transplant recipients. From two hospitals in southern Brazil, we collected the following data on lung transplant recipients who developed pulmonary tuberculosis: gender; age; symptoms; the lung disease that led to transplantation; HRCT pattern; distribution of findings; time from transplantation to pulmonary tuberculosis; and mortality rate. The HRCT findings were classified as miliary nodules; cavitation and centrilobular nodules with a tree-in-bud pattern; ground-glass attenuation with consolidation; mediastinal lymph node enlargement; or pleural effusion. We evaluated 402 lung transplant recipients, 19 of whom developed pulmonary tuberculosis after transplantation. Among those 19 patients, the most common HRCT patterns were ground-glass attenuation with consolidation (in 42%); cavitation and centrilobular nodules with a tree-in-bud pattern (in 31.5%); and mediastinal lymph node enlargement (in 15.7%). Among the patients with cavitation and centrilobular nodules with a tree-in-bud pattern, the distribution was within the upper lobes in 66.6%. No pleural effusion was observed. Despite treatment, one-year mortality was 47.3%. The predominant HRCT pattern was ground-glass attenuation with consolidation, followed by cavitation and centrilobular nodules with a tree-in-bud pattern. These findings are similar to those reported for immunocompetent patients with pulmonary tuberculosis and considerably different from those reported for AIDS patients with the same disease.

  11. Characteristics of Consolidation, Centrilobular Nodule and Bronchus as CT Findings for the Differentiation between Tuberculosis and Pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Se Young; Chung, Myung Hee; Lim, Yeon Soo; Lim, Hyun Wook; Kahng, Ji Min [Bucheon St. Mary' s Hospital, The Catholic University of Korea College of Medicine, Bucheon (Korea, Republic of); Sung, Mi Sook [Dept. of Radiology, St. Paul' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    2013-06-15

    To differentiate tuberculosis from pneumonia by computed tomography (CT) in cases difficult to diagnose clinically and radiologically. CT scans of 300 patients with tuberculosis and 234 patients with pneumonia were retrospectively analyzed. Parenchymal abnormalities, lymph nodes, pleural effusions and central bronchial narrowing were evaluated. The density of consolidation was measured by pre- and post-enhanced CT. Centrilobular nodules, granulomas, cavitations in both nodules as well as consolidation, conglomerated nodules, and enlarged lymph nodes occurred with significantly greater frequency in patients with tuberculosis than in those with pneumonia. Centrilobular nodules were larger and denser in tuberculosis patients. In consolidation, decreases in lung lobe volume and a bronchial beaded appearance (irregular narrowing and dilatation) were more frequent in patients with tuberculosis. The tuberculous consolidation had significantly lower mean enhancement and net enhancement than that from pneumonia. When the diagnostic criteria for tuberculosis were set as well-demarcated larger centrilobular nodules and/or a lowerly enhancing consolidation with internal beaded bronchi, the diagnostic accuracy was found to be 82.0%. Consolidation with a low level of enhancement, decreased lung lobe volume, and bronchi with irregular, beaded shape and denser and larger centrilobular nodules are helpful CT findings for the diagnosis of tuberculosis.

  12. The value of FDG-PET/CT in assessing single pulmonary nodules in patients at high risk of lung cancer

    International Nuclear Information System (INIS)

    Kagna, Olga; Solomonov, Anna; Fruchter, Oren; Keidar, Zohar; Bar-Shalom, Rachel; Israel, Ora; Yigla, Mordechai; Guralnik, Luda

    2009-01-01

    To evaluate whether PET/low-dose CT (ldCT) using 18 F-fluorodeoxyglucose (FDG) improves characterization of indeterminate single pulmonary nodules (SPNs) in patients at high risk of lung cancer. Retrospective analysis of 307 patients who underwent FDG-PET/CT for indeterminate SPNs identified 93 (70 men, age range 46-90 years) at high risk of lung cancer (age >40 years, minimum 10 pack-year smokers). SPNs were evaluated for the presence and intensity of FDG avidity and ldCT patterns. The performance of visual and semiquantitative FDG-PET/ldCT algorithms for characterization of SPNs was compared to that of ldCT. Incongruent FDG-PET and ldCT patterns were analyzed for significance in further patient management. Malignancy was diagnosed in 38% patients. FDG avidity defined 33 SPNs as true-positive (TP) and 2 as false-negative (FN) (malignant), and 41 as true-negative (TN) and 17 as false-positive (FP) (benign). For SUVmax of 2.2 (by ROC analysis) there were 27 TP, 8 FN, 48 TN and 10 FP SPNs. LdCT defined 34 TP, 1 FN, 28 TN and 30 FP lesions. Of the FP lesions on ldCT, 60% were FDG-negative. Visual PET/ldCT analysis had a sensitivity of 94%, a specificity of 70%, an accuracy of 80%, a positive predictive value (PPV) of 66%, and a negative predictive value (NPV) of 95% as compared to 77%, 83%, 81%, 73%, 86% for semiquantitative PET/ldCT and 97%, 48%, 66%, 53%, 96% for ldCT, respectively. Both PET/ldCT algorithms had statistically significantly higher specificity and accuracy than ldCT. Semiquantitative analysis showed significantly higher PPV and lower sensitivity and NPV than found with ldCT. A single screening procedure encompassing FDG-PET and ldCT may improve screening for lung cancer in high-risk patients. The significantly improved specificity may potentially reduce FP ldCT results and further unnecessary invasive procedures. (orig.)

  13. Predicting adenocarcinoma recurrence using computational texture models of nodule components in lung CT

    International Nuclear Information System (INIS)

    Depeursinge, Adrien; Yanagawa, Masahiro; Leung, Ann N.; Rubin, Daniel L.

    2015-01-01

    Purpose: To investigate the importance of presurgical computed tomography (CT) intensity and texture information from ground-glass opacities (GGO) and solid nodule components for the prediction of adenocarcinoma recurrence. Methods: For this study, 101 patients with surgically resected stage I adenocarcinoma were selected. During the follow-up period, 17 patients had disease recurrence with six associated cancer-related deaths. GGO and solid tumor components were delineated on presurgical CT scans by a radiologist. Computational texture models of GGO and solid regions were built using linear combinations of steerable Riesz wavelets learned with linear support vector machines (SVMs). Unlike other traditional texture attributes, the proposed texture models are designed to encode local image scales and directions that are specific to GGO and solid tissue. The responses of the locally steered models were used as texture attributes and compared to the responses of unaligned Riesz wavelets. The texture attributes were combined with CT intensities to predict tumor recurrence and patient hazard according to disease-free survival (DFS) time. Two families of predictive models were compared: LASSO and SVMs, and their survival counterparts: Cox-LASSO and survival SVMs. Results: The best-performing predictive model of patient hazard was associated with a concordance index (C-index) of 0.81 ± 0.02 and was based on the combination of the steered models and CT intensities with survival SVMs. The same feature group and the LASSO model yielded the highest area under the receiver operating characteristic curve (AUC) of 0.8 ± 0.01 for predicting tumor recurrence, although no statistically significant difference was found when compared to using intensity features solely. For all models, the performance was found to be significantly higher when image attributes were based on the solid components solely versus using the entire tumors (p < 3.08 × 10 −5 ). Conclusions: This study

  14. Computer-assisted solid lung nodule 3D volumetry on CT. Influence of scan mode and iterative reconstruction. A CT phantom study

    International Nuclear Information System (INIS)

    Coenen, Adriaan; Honda, Osamu; Tomiyama, Noriyuki; Jagt, Eric J. van der

    2013-01-01

    The objective of this study was to evaluate the effect of high-resolution scan mode and iterative reconstruction on lung nodule 3D volumetry. Solid nodules with various sizes (5, 8, 10 and 12 mm) were placed inside a chest phantom. CT images were obtained with various tube currents, scan modes (conventional mode, high-resolution mode) and iterative reconstructions [0, 50 and 100% blending of adaptive statistical iterative reconstruction (ASiR) and filtered back projection]. The nodule volumes were calculated using semiautomatic software and compared with the assumed volume from the nodules. The mean absolute and relative percentage error improved when using iterative reconstruction especially when using the conventional scan mode; however, this effect was not significant. Significant reduction in volume overestimation was observed when using high-resolution scan mode (P=0.011). The high-resolution mode significantly reduces the volume overestimation of 3D volumetry. Iterative reconstruction shows a reduction in volume overestimation and error margin especially with the conventional scan mode; however, this effect was not significant. (author)

  15. High resolution computed tomography(HRCT) findings of a solitary pulmonary nodule : differential diagnosis of cancer and tuberculosis

    International Nuclear Information System (INIS)

    Kim, Hee Soo; Choe, Kyu Ok

    1996-01-01

    To evaluate the role of HRCT in the differentiation of Pulmonary tuberculosis and lung cancer, where the manifestation of disease is a solitary pulmonary nodule(SPN). Forty eight SPNs including 29 cancers proven by surgery(n=10), by bronchoscopic biopsy(n=7) and by fine needle aspiration biopsy(n=12), and 19 tuberculous nodules proven by surgery(n=4), by bronchoscopic biopsy(n=4), by fine needle aspiration biopsy(n=5), by a positive result in AFB culture without evidence of malignant cells(n=3), and by a decrease in size on serial plain chests despite negative AFB culture(n=3) were included. Scanning parameters for HRCT were 140 KVp, 170 mA, 1.5 mm collimation, 3 sec scanning time, and a high spatial frequency algorithm was used. With regard to the marginal features of nodules, the findings more commonly observed in malignant nodules were greater average length of the longest spicule(5.35 ± 3.19 mm versus 2.75 ± 1.56 mm), and more commonspiculated nodules greater than 3 cm in diameter, 16(55%) versus 2(10.5%)(p<0.05). Regarding the internal characteristics of nodules and perinodular parenchymal changes, the findings more commonly observed in cases of cancer were air-bronchograms within nodules(14 ; 48.3%) and interlobar fissure puckering (6 ; 20.7%), whereas in tuberculosis cases the most common findings were low density of nodule(16 ; 84.2%), cavitation(12 ; 63.1%), and perinodular focal lung hypodensity(5 ; 26.3%), (p<0.05). no statstically significant difference was observed between the incidence of satellite lesion of tuberculous(73.7%) and of malignant nodules(34.5%). However, perilobular nodules or bronchovascular bundle thickening s were more commonly observed in the satellite lesions of malignant nodules(9 ; 90%), whereas centrilobular nodules or lobular consolidation were more commonly observed in those of tuberculous nodules(12 ; 85.7%), (p<0.05). HRCT provides detailed information concerning perinodular parenchymal changes and characteristics of

  16. CT-guided marking of pulmonary nodules with a special lung marking wire before video-assisted thoracoscopic surgery. Review of 184 cases; CT-gestuetzte Drahtmarkierung vor videoassistierter thorakoskopischer OP von pulmonalen Rundherden. Eine Auswertung von 184 Faellen

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, M.K.; Eichfeld, U.; Kahn, T.; Stumpp, P. [Universitaetsklinikum Leipzig AoeR (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie

    2012-06-15

    Purpose: Minimally invasive techniques like video-assisted thoracoscopic surgery (VATS) are currently the method of choice for the resection of small pulmonary nodules, when they are located in the periphery of the lungs. To guarantee quick and safe intraoperative identification of the nodule, preoperative marking is necessary and sensible. We report about our experiences in 184 markings with a special lung marking wire, which is placed in or around the pulmonary nodule using CT guidance. Materials and Methods: In 184 patients (97 m, 87f, mean age: 58.1 {+-} 13.7 years) with pulmonary nodules, scheduled for resection with VATS, a special lung marking wire was placed preoperatively under CT guidance. We evaluated the technical success, safety, necessity of conversion to thoracotomy and histology in all patients. Results: The marking wire could be positioned successfully in 181 cases (98.4 %). There was one major complication (uncontrollable pneumothorax). Minor adverse events like small pneumothorax (53.3 %) or a perifocal bleeding (30.4 %) did not necessitate treatment. Complete resection of the marked nodule was successful in 98.4 % of the patients. Conversion to thoracotomy was necessary in 29 patients (15.9 %) due to bleeding, adhesions, malignancy or wire dislocation. Histology revealed a benign nodule in 96 cases (54.4 %) and a malignant lesion in 78 cases (45.6 %), of which only 21 nodules (11.5 %) turned out to present a primary pulmonary carcinoma. Conclusion: CT-guided marking of pulmonary nodules using a special marking wire followed by thoracoscopic resection is an efficient and safe method for diagnosing suspicious nodules in the periphery of the lung. (orig.)

  17. Adaptive statistical iterative reconstruction-applied ultra-low-dose CT with radiography- comparable radiation dose: Usefulness for lung nodule detection

    International Nuclear Information System (INIS)

    Yoon, Hyun Jung; Chung, Myung Jin; Hwang, Hye Sun; Lee, Kyung Soo; Moon, Jung Won

    2015-01-01

    To assess the performance of adaptive statistical iterative reconstruction (ASIR)-applied ultra-low-dose CT (ULDCT) in detecting small lung nodules. Thirty patients underwent both ULDCT and standard dose CT (SCT). After determining the reference standard nodules, five observers, blinded to the reference standard reading results, independently evaluated SCT and both subsets of ASIR- and filtered back projection (FBP)-driven ULDCT images. Data assessed by observers were compared statistically. Converted effective doses in SCT and ULDCT were 2.81 ± 0.92 and 0.17 ± 0.02 mSv, respectively. A total of 114 lung nodules were detected on SCT as a standard reference. There was no statistically significant difference in sensitivity between ASIR-driven ULDCT and SCT for three out of the five observers (p = 0.678, 0.735, < 0.01, 0.038, and < 0.868 for observers 1, 2, 3, 4, and 5, respectively). The sensitivity of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT in three out of the five observers (p < 0.01 for three observers, and p = 0.064 and 0.146 for two observers). In jackknife alternative free-response receiver operating characteristic analysis, the mean values of figure-of-merit (FOM) for FBP, ASIR-driven ULDCT, and SCT were 0.682, 0.772, and 0.821, respectively, and there were no significant differences in FOM values between ASIR-driven ULDCT and SCT (p = 0.11), but the FOM value of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT and SCT (p = 0.01 and 0.00). Adaptive statistical iterative reconstruction-driven ULDCT delivering a radiation dose of only 0.17 mSv offers acceptable sensitivity in nodule detection compared with SCT and has better performance than FBP-driven ULDCT

  18. Adaptive statistical iterative reconstruction-applied ultra-low-dose CT with radiography- comparable radiation dose: Usefulness for lung nodule detection

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyun Jung; Chung, Myung Jin; Hwang, Hye Sun; Lee, Kyung Soo [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Moon, Jung Won [Dept. of Radiology, Kangbuk Samsung Hospital, Seoul (Korea, Republic of)

    2015-10-15

    To assess the performance of adaptive statistical iterative reconstruction (ASIR)-applied ultra-low-dose CT (ULDCT) in detecting small lung nodules. Thirty patients underwent both ULDCT and standard dose CT (SCT). After determining the reference standard nodules, five observers, blinded to the reference standard reading results, independently evaluated SCT and both subsets of ASIR- and filtered back projection (FBP)-driven ULDCT images. Data assessed by observers were compared statistically. Converted effective doses in SCT and ULDCT were 2.81 ± 0.92 and 0.17 ± 0.02 mSv, respectively. A total of 114 lung nodules were detected on SCT as a standard reference. There was no statistically significant difference in sensitivity between ASIR-driven ULDCT and SCT for three out of the five observers (p = 0.678, 0.735, < 0.01, 0.038, and < 0.868 for observers 1, 2, 3, 4, and 5, respectively). The sensitivity of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT in three out of the five observers (p < 0.01 for three observers, and p = 0.064 and 0.146 for two observers). In jackknife alternative free-response receiver operating characteristic analysis, the mean values of figure-of-merit (FOM) for FBP, ASIR-driven ULDCT, and SCT were 0.682, 0.772, and 0.821, respectively, and there were no significant differences in FOM values between ASIR-driven ULDCT and SCT (p = 0.11), but the FOM value of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT and SCT (p = 0.01 and 0.00). Adaptive statistical iterative reconstruction-driven ULDCT delivering a radiation dose of only 0.17 mSv offers acceptable sensitivity in nodule detection compared with SCT and has better performance than FBP-driven ULDCT.

  19. Adaptive Statistical Iterative Reconstruction-Applied Ultra-Low-Dose CT with Radiography-Comparable Radiation Dose: Usefulness for Lung Nodule Detection.

    Science.gov (United States)

    Yoon, Hyun Jung; Chung, Myung Jin; Hwang, Hye Sun; Moon, Jung Won; Lee, Kyung Soo

    2015-01-01

    To assess the performance of adaptive statistical iterative reconstruction (ASIR)-applied ultra-low-dose CT (ULDCT) in detecting small lung nodules. Thirty patients underwent both ULDCT and standard dose CT (SCT). After determining the reference standard nodules, five observers, blinded to the reference standard reading results, independently evaluated SCT and both subsets of ASIR- and filtered back projection (FBP)-driven ULDCT images. Data assessed by observers were compared statistically. Converted effective doses in SCT and ULDCT were 2.81 ± 0.92 and 0.17 ± 0.02 mSv, respectively. A total of 114 lung nodules were detected on SCT as a standard reference. There was no statistically significant difference in sensitivity between ASIR-driven ULDCT and SCT for three out of the five observers (p = 0.678, 0.735, ASIR-driven ULDCT in three out of the five observers (p ASIR-driven ULDCT, and SCT were 0.682, 0.772, and 0.821, respectively, and there were no significant differences in FOM values between ASIR-driven ULDCT and SCT (p = 0.11), but the FOM value of FBP-driven ULDCT was significantly lower than that of ASIR-driven ULDCT and SCT (p = 0.01 and 0.00). Adaptive statistical iterative reconstruction-driven ULDCT delivering a radiation dose of only 0.17 mSv offers acceptable sensitivity in nodule detection compared with SCT and has better performance than FBP-driven ULDCT.

  20. Additional effects of FDG-PET to thin-section CT for the differential diagnosis of lung nodules. A Japanese multicenter clinical study

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Murakami, Koji; Inoue, Tomio; Saga, Tsuneo; Shiomi, Susumu

    2011-01-01

    This study was a controlled multicenter clinical study on patients with peripheral lung nodules to verify the improvement in the diagnostic ability of fluorodeoxyglucose-positron emission tomography (FDG-PET) when used in combination with thin-section CT (TS-CT). Patients with peripheral lung nodules (long maximal diameter: 10-30 mm) detected using CT were examined using TS-CT and FDG-PET for the differential diagnosis of benign or malignant lesions. The primary endpoint was the specificity of the results using a combination of TS-CT and FDG-PET, compared with the results for TS-CT alone. Images were interpreted by investigators at each institution. Blind readings were also performed by an independent image interpretation committee. The gold standard was a pathological diagnosis determined using a surgical or biopsy specimen obtained after PET; and the patients in whom a pathological diagnosis could not be obtained were diagnosed based on a follow-up TS-CT performed more than 6 months later. Adverse reactions to FDG were also evaluated. The blind reading results for 82 lesions in 81 subjects eligible for analysis among the 90 subjects included in the study showed a specificity of 91.2% (31/34) (95% confidence interval (CI): 76.3-98.1) for TS-CT + PET, compared with a specificity of 67.6% (23/34) (95% CI: 49.5-82.6) for TS-CT alone. The specificity was significantly improved by the addition of the PET findings (p<0.05). The sensitivity improved from 89.6% (43/48) for TS-CT to 91.7% (44/48) for TS-CT + PET; the addition of PET increased the level of confidence in the diagnosis, but the difference was not significant. The results reported by the institutional investigators were not significantly different. No serious adverse reactions occurred, although two of the 90 subjects exhibited mild adverse reactions. The addition of FDG-PET to TS-CT for the differential diagnosis of benign or malignant peripheral lung nodules resulted in a significant improvement in

  1. CT volumetry of artificial pulmonary nodules using an ex vivo lung phantom: Influence of exposure parameters and iterative reconstruction on reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Wielpütz, Mark O., E-mail: Mark.wielpuetz@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Translational Lung Research Center (TLRC-H), German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Lederlin, Mathieu, E-mail: mathieu.lederlin@chu-bordeaux.fr [Department of Thoracic and Cardiovascular Imaging, University Hospital of Bordeaux, Av de Magellan, 33600 Pessac (France); Department of Radiology, German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Wroblewski, Jacek, E-mail: JacekWr@gmx.net [Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Translational Lung Research Center (TLRC-H), German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Dinkel, Julien, E-mail: jdinkel@partners.org [Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114 (United States); Department of Radiology, German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Translational Lung Research Center (TLRC-H), German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Eichinger, Monika, E-mail: Monika.eichinger@thoraxklinik-heidelberg.de [Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Amalienstr. 5, 69126 Heidelberg (Germany); Translational Lung Research Center (TLRC-H), German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Department of Radiology, German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); and others

    2013-09-15

    Objectives: To evaluate the influence of exposure parameters and raw-data based iterative reconstruction (IR) on the measurement variability of computer-aided nodule volumetry on chest multidetector computed tomography (MDCT). Materials and methods: N = 7 porcine lung explants were inflated in a dedicated ex vivo phantom and prepared with n = 162 artificial nodules. MDCT was performed eight consecutive times (combinations of 120 and 80 kV with 120, 60, 30 and 12 mA s), and reconstructed with filtered back projection (FBP) and IR. Nodule volume and diameter were measured semi-automatically with dedicated software. The absolute percentage measurement error (APE) was computed in relation to the 120 kV 120 mA s acquisition. Noise was recorded for each nodule in every dataset. Results: Mean nodule volume and diameter were 0.32 ± 0.15 ml and 12.0 ± 2.6 mm, respectively. Although IR reduced noise by 24.9% on average compared to FBP (p < 0.007), APE with IR was equal to or slightly higher than with FBP. Mean APE for volume increased significantly below a volume computed tomography dose index (CTDI) of 1.0 mGy: for 120 kV 12 mA s APE was 3.8 ± 6.2% (FBP) vs. 4.0 ± 5.2% (IR) (p < 0.007); for 80 kV 12 mA s APE was 8.0 ± 13.0% vs. 9.3 ± 15.8% (n.s.), respectively. Correlating APE with image noise revealed that at identical noise APE was higher with IR than with FBP (p < 0.05). Conclusions: Computer-aided volumetry is robust in a wide range of exposure settings, and reproducibility is reduced at a CTDI below 1.0 mGy only, but the error rate remains clinically irrelevant. Noise reduction by IR is not detrimental for measurement error in the setting of semi-automatic nodule volumetry on chest MDCT.

  2. CT volumetry of artificial pulmonary nodules using an ex vivo lung phantom: Influence of exposure parameters and iterative reconstruction on reproducibility

    International Nuclear Information System (INIS)

    Wielpütz, Mark O.; Lederlin, Mathieu; Wroblewski, Jacek; Dinkel, Julien; Eichinger, Monika

    2013-01-01

    Objectives: To evaluate the influence of exposure parameters and raw-data based iterative reconstruction (IR) on the measurement variability of computer-aided nodule volumetry on chest multidetector computed tomography (MDCT). Materials and methods: N = 7 porcine lung explants were inflated in a dedicated ex vivo phantom and prepared with n = 162 artificial nodules. MDCT was performed eight consecutive times (combinations of 120 and 80 kV with 120, 60, 30 and 12 mA s), and reconstructed with filtered back projection (FBP) and IR. Nodule volume and diameter were measured semi-automatically with dedicated software. The absolute percentage measurement error (APE) was computed in relation to the 120 kV 120 mA s acquisition. Noise was recorded for each nodule in every dataset. Results: Mean nodule volume and diameter were 0.32 ± 0.15 ml and 12.0 ± 2.6 mm, respectively. Although IR reduced noise by 24.9% on average compared to FBP (p < 0.007), APE with IR was equal to or slightly higher than with FBP. Mean APE for volume increased significantly below a volume computed tomography dose index (CTDI) of 1.0 mGy: for 120 kV 12 mA s APE was 3.8 ± 6.2% (FBP) vs. 4.0 ± 5.2% (IR) (p < 0.007); for 80 kV 12 mA s APE was 8.0 ± 13.0% vs. 9.3 ± 15.8% (n.s.), respectively. Correlating APE with image noise revealed that at identical noise APE was higher with IR than with FBP (p < 0.05). Conclusions: Computer-aided volumetry is robust in a wide range of exposure settings, and reproducibility is reduced at a CTDI below 1.0 mGy only, but the error rate remains clinically irrelevant. Noise reduction by IR is not detrimental for measurement error in the setting of semi-automatic nodule volumetry on chest MDCT

  3. The feasibility of 11C-methionine-PET in diagnosis of solitary lung nodules/masses when compared with 18F-FDG-PET

    International Nuclear Information System (INIS)

    Hsieh Hungjen; Lin Shenghsiang; Lin Kohan; Lee Chienying; Chang Chengpei; Wang Shyhjen

    2008-01-01

    The objective of this study was to differentiate between benign and malignant lesions of the lung, 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG-PET) has limitations such as a lower specificity in cases of non-specific inflammation. The positive predictive value is unsatisfactory in countries where inflammatory lung disorders are prevalent. We present the preliminary results of the usefulness of combining 11 C-methionine-PET and 18 F-FDG-PET in this context. Fifteen patients with indeterminate solitary pulmonary nodules/masses (10 men, 5 women; average age 64.7±14.0 years, ranging from 25 to 87 years) were studied using 11 C-methionine- and 18 F-FDG-PET. Interpretations were primarily made on visual analysis with five-point scale and a consensus of two nuclear medicine physicians, using standardized uptake value as an accessory reference. Foci of abnormal radiotracer uptake were subsequently correlated with clinical follow-up, imaging modalities such as chest radiography, chest computed tomography (CT), serial PET studies, and pathology results from bronchoscopic biopsy and/or surgical specimen. Diagnoses were established in 14 patients. The 11 C-methionine-PET and 18 F-FDG-PET studies were both true positive in two cases of adenocarcinoma and true negative in two cases of clinical benign nodules. In one case of lymphoid hyperplasia both 11 C-methionine-PET and 18 F-FDG-PET showed false-positive findings. Discordant results were obtained in nine cases. In spite of the false-positive results of 18 F-FDG-PET, 11 C-methionine-PET was true negative in four cases with chronic inflammatory nodules and three cases of pulmonary tuberculosis. Furthermore, 11 C-methionine-PET was true positive in one case of lung metastasis of thyroid cancer, and in another with recurrence of gastric cancer, respectively, for which 18 F-FDG-PET imaging was false negative. Our experience indicates that 11 C-methionine-PET seems more specific and sensitive when compared with

  4. Clinical significance of pulmonary nodules detected on abdominal CT in pediatric patients

    International Nuclear Information System (INIS)

    Breen, Micheal; Lee, Edward Y.; Zurakowski, David

    2015-01-01

    The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children. The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children. This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms ''nodule,'' ''nodular'' or ''mass'' in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules. Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these

  5. Clinical significance of pulmonary nodules detected on abdominal CT in pediatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Micheal; Lee, Edward Y. [Boston Children' s Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Zurakowski, David [Boston Children' s Hospital and Harvard Medical School, Departments of Anesthesiology and Surgery, Boston, MA (United States)

    2015-11-15

    The clinical significance of a pulmonary nodule that is detected incidentally on CT studies in children is unknown. In addition, there is limited information regarding the management of incidentally detected pulmonary nodules discovered on abdominal CT studies in children. The purpose of this study was to investigate the clinical significance of incidental pulmonary nodules detected on abdominal CT studies in children. This was a retrospective study performed following institutional review board approval. Abdominal CT reports in patients younger than 18 years of age from July 2004 to June 2011 were reviewed for the terms ''nodule,'' ''nodular'' or ''mass'' in reference to the lung bases. The study population included those pediatric patients in whom pulmonary nodules were initially detected on abdominal CT studies. The largest pulmonary nodules detected on CT studies were evaluated for their features (size, shape, margin, attenuation, location, and presence of calcification and cavitation). Follow-up CT studies and clinical records were reviewed for demographic information, history of underlying malignancies and the clinical outcome of the incidental pulmonary nodules. Comparison of malignant versus benign pulmonary nodules was performed with respect to the size of the nodule, imaging features on CT, and patient history of malignancy using the Student's t-test and Fisher exact test. Youden J-index in receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off size for suggesting a high risk of malignancy of incidentally detected pulmonary nodules. Pulmonary nodules meeting inclusion criteria were detected in 62 (1.2%) of 5,234 patients. The mean age of patients with nodules was 11.2 years (range: 5 months-18 years). Thirty-one patients (50%) had follow-up CT studies and two of these patients (6%) were subsequently found to have malignant pulmonary nodules. Both of these

  6. Solitary pulmonary nodule: radiologic features and diagnostic approach

    International Nuclear Information System (INIS)

    Rodriguez Cambronero, Luis Enrique

    2012-01-01

    A literature review is conducted on the solitary pulmonary nodule, to determine the diagnostic methods and specific characteristics. The diagnostic methods used have been: chest radiography, computed tomography, positron emission tomography and magnetic resonance imaging. The radiological features are defined: location, size, definition of contours or edges (margins), densitometric and attenuation characteristics, cavitation, air bronchogram, growth, doubling time, satellite nodules, nutrient vessels [es

  7. Thyroid nodule

    International Nuclear Information System (INIS)

    McKenney, J.F.

    1975-01-01

    A palpable mass or nodule may represent any one of a large and diverse group of conditions that involve the thyroid. Whether the patient is euthyroid, hypothyroid, or hyperthyroid can be assessed, and the cause of hypofunction or hyperfunction can usually be determined. Scintiscanning provides important information on the anatomic structure of thyroid nodules. A hot nodule should be ablated by either radioiodine or surgery. A warm nodule usually responds to suppression therapy; if regression does not occur, the problem should be reevaluated. A cold nodule should be surgically excised, as microscopic study of such a lesion is mandatory

  8. Diagnosing lung nodules on oncologic MR/PET imaging: Comparison of fast T1-weighted sequences and influence of image acquisition in inspiration and expiration breath-hold

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, Nina F.; Seith, Ferdinand; Gatidis, Sergios; Brendle, Cornelia; Schmidt, Holger; Pfannenberg, Christina A; LaFougère, Christian; Nikolaou, Konstantin; Schraml, Christina [University Hospital of Tuebingen, Tuebingen (Germany)

    2016-09-15

    First, to investigate the diagnostic performance of fast T1-weighted sequences for lung nodule evaluation in oncologic magnetic resonance (MR)/positron emission tomography (PET). Second, to evaluate the influence of image acquisition in inspiration and expiration breath-hold on diagnostic performance. The study was approved by the local Institutional Review Board. PET/CT and MR/PET of 44 cancer patients were evaluated by 2 readers. PET/CT included lung computed tomography (CT) scans in inspiration and expiration (CTin, CTex). MR/PET included Dixon sequence for attenuation correction and fast T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences (volume interpolated breath-hold examination acquired in inspiration [VIBEin], volume interpolated breath-hold examination acquired in expiration [VIBEex]). Diagnostic performance was analyzed for lesion-, lobe-, and size-dependence. Diagnostic confidence was evaluated (4-point Likert-scale; 1 = high). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed. Seventy-six pulmonary lesions were evaluated. Lesion-based detection rates were: CTex, 77.6%; VIBEin, 53.3%; VIBEex, 51.3%; and Dixon, 22.4%. Lobe-based detection rates were: CTex, 89.6%; VIBEin, 58.3%; VIBEex, 60.4%; and Dixon, 31.3%. In contrast to CT, inspiration versus expiration did not alter diagnostic performance in VIBE sequences. Diagnostic confidence was best for VIBEin and CTex and decreased in VIBEex and Dixon (1.2 ± 0.6; 1.2 ± 0.7; 1.5 ± 0.9; 1.7 ± 1.1, respectively). The JAFROC figure-of-merit of Dixon was significantly lower. All patients with malignant lesions were identified by CTex, VIBEin, and VIBEex, while 3 patients were false-negative in Dixon. Fast T1-weighted VIBE sequences allow for identification of patients with malignant pulmonary lesions. The Dixon sequence is not recommended for lung nodule evaluation in oncologic MR/PET patients. In contrast to CT, inspiration versus

  9. Diagnosing Lung Nodules on Oncologic MR/PET Imaging: Comparison of Fast T1-Weighted Sequences and Influence of Image Acquisition in Inspiration and Expiration Breath-Hold

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, Nina F.; Seith, Ferdinand; Gatidis, Sergios [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Brendle, Cornelia [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Department of Diagnostic and Interventional Neuroradiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Schmidt, Holger; Pfannenberg, Christina A. [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Fougère, Christian la [Department of Nuclear Medicine, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Nikolaou, Konstantin; Schraml, Christina [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany)

    2016-11-01

    First, to investigate the diagnostic performance of fast T1-weighted sequences for lung nodule evaluation in oncologic magnetic resonance (MR)/positron emission tomography (PET). Second, to evaluate the influence of image acquisition in inspiration and expiration breath-hold on diagnostic performance. The study was approved by the local Institutional Review Board. PET/CT and MR/PET of 44 cancer patients were evaluated by 2 readers. PET/CT included lung computed tomography (CT) scans in inspiration and expiration (CTin, CTex). MR/PET included Dixon sequence for attenuation correction and fast T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences (volume interpolated breath-hold examination acquired in inspiration [VIBEin], volume interpolated breath-hold examination acquired in expiration [VIBEex]). Diagnostic performance was analyzed for lesion-, lobe-, and size-dependence. Diagnostic confidence was evaluated (4-point Likert-scale; 1 = high). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed. Seventy-six pulmonary lesions were evaluated. Lesion-based detection rates were: CTex, 77.6%; VIBEin, 53.3%; VIBEex, 51.3%; and Dixon, 22.4%. Lobe-based detection rates were: CTex, 89.6%; VIBEin, 58.3%; VIBEex, 60.4%; and Dixon, 31.3%. In contrast to CT, inspiration versus expiration did not alter diagnostic performance in VIBE sequences. Diagnostic confidence was best for VIBEin and CTex and decreased in VIBEex and Dixon (1.2 ± 0.6; 1.2 ± 0.7; 1.5 ± 0.9; 1.7 ± 1.1, respectively). The JAFROC figure-of-merit of Dixon was significantly lower. All patients with malignant lesions were identified by CTex, VIBEin, and VIBEex, while 3 patients were false-negative in Dixon. Fast T1-weighted VIBE sequences allow for identification of patients with malignant pulmonary lesions. The Dixon sequence is not recommended for lung nodule evaluation in oncologic MR/PET patients. In contrast to CT, inspiration versus

  10. Detection of pulmonary nodules on lung X-ray images. Studies on multi-resolutional filter and energy subtraction images

    International Nuclear Information System (INIS)

    Sawada, Akira; Sato, Yoshinobu; Kido, Shoji; Tamura, Shinichi

    1999-01-01

    The purpose of this work is to prove the effectiveness of an energy subtraction image for the detection of pulmonary nodules and the effectiveness of multi-resolutional filter on an energy subtraction image to detect pulmonary nodules. Also we study influential factors to the accuracy of detection of pulmonary nodules from viewpoints of types of images, types of digital filters and types of evaluation methods. As one type of images, we select an energy subtraction image, which removes bones such as ribs from the conventional X-ray image by utilizing the difference of X-ray absorption ratios at different energy between bones and soft tissue. Ribs and vessels are major causes of CAD errors in detection of pulmonary nodules and many researches have tried to solve this problem. So we select conventional X-ray images and energy subtraction X-ray images as types of images, and at the same time select ∇ 2 G (Laplacian of Guassian) filter, Min-DD (Minimum Directional Difference) filter and our multi-resolutional filter as types of digital filters. Also we select two evaluation methods and prove the effectiveness of an energy subtraction image, the effectiveness of Min-DD filter on a conventional X-ray image and the effectiveness of multi-resolutional filter on an energy subtraction image. (author)

  11. [Thyroid nodule].

    Science.gov (United States)

    Clerc, Jérôme

    2005-01-31

    The thyroid nodule is a frequent, most often benign, chronic, multifocal and slowly progressive disease. The first line strategy is to diagnose cancerous nodules (thyroid nodules is controversial since the prognosis of thyroid cancer is excellent for lesions measuring less than 20 mm. Though imaging accuracy is quite limited in assessing the diagnosis of thyroid cancer, both ultrasounds (US) and thyroid scan are helpful to enhance nodular identification (>30%), to sort the nodules relevant for cytological sampling and to optimize the follow-up, the major source of health costs. Suspicious and non contributive FNAs must have a control FNA within 6 months. Nodules with a non suspicious FNA (>85%) require long term follow-up. This follow-up is mainly morphological. New or evolutive nodules, as assessed by palpation or US, will require iterative FNAs or should be considered for surgery. In patients with hyperfunctioning nodules on the scan (10 to 20%), a yearly evaluation of the TSH level is sufficient. These nodules account either for autonomously functioning ones, which slowly develop towards thyrotoxicosis, or for hyperplastic nodules frequently disclosing a lymphocytic thyroiditis. Morbidity due to thyroid autonomy is still underestimated especially in aging patients with TSH levels thyroid nodule is suggested.

  12. Phased searching with NEAT in a time-scaled framework: experiments on a computer-aided detection system for lung nodules.

    Science.gov (United States)

    Tan, Maxine; Deklerck, Rudi; Cornelis, Jan; Jansen, Bart

    2013-11-01

    In the field of computer-aided detection (CAD) systems for lung nodules in computed tomography (CT) scans, many image features are presented and many artificial neural network (ANN) classifiers with various structural topologies are analyzed; frequently, the classifier topologies are selected by trial-and-error experiments. To avoid these trial and error approaches, we present a novel classifier that evolves ANNs using genetic algorithms, called "Phased Searching with NEAT in a Time or Generation-Scaled Framework", integrating feature selection with the classification task. We analyzed our method's performance on 360 CT scans from the public Lung Image Database Consortium database. We compare our method's performance with other more-established classifiers, namely regular NEAT, Feature-Deselective NEAT (FD-NEAT), fixed-topology ANNs, and support vector machines (SVMs) using ten-fold cross-validation experiments of all 360 scans. The results show that the proposed "Phased Searching" method performs better and faster than regular NEAT, better than FD-NEAT, and achieves sensitivities at 3 and 4 false positives (FP) per scan that are comparable with the fixed-topology ANN and SVM classifiers, but with fewer input features. It achieves a detection sensitivity of 83.0±9.7% with an average of 4FP/scan, for nodules with a diameter greater than or equal to 3mm. It also evolves networks with shorter evolution times and with lower complexities than regular NEAT (p=0.026 and pNEAT and by our approach shows that our approach searches for good solutions in lower dimensional search spaces, and evolves networks without superfluous structure. We have presented a novel approach that combines feature selection with the evolution of ANN topology and weights. Compared with the original threshold-based Phased Searching method of Green, our method requires fewer parameters and converges to the optimal network complexity required for the classification task at hand. The results of the

  13. CT SCAN EVALUATION OF PULMONARY NODULE

    Directory of Open Access Journals (Sweden)

    A. Ravi Kumar

    2016-06-01

    Full Text Available BACKGROUND Lung carcinomas are quite commonly diagnosed. Thanks to the ever increasing smokers’ population. Majority of the city dwellers are at a higher risk of having this disease when compared to the village counterparts. The stigma through which the person and the family have to undergo before confirming the diagnosis is enormous. So the radiographic methods of diagnosing the malignancies have to improve. Before confirming the diagnosis, the radiologists, the treating physicians should be somewhat confident about the diagnosis so as to prepare the patients and their relatives for the most probable diagnosis before the confirmatory report. The confirmatory procedures include the PET scan and the Histopathology. Both are time consuming procedures and in an economy like ours, finding a PET scanning centre is rather difficult. So the most probable diagnosis has to be thought of using minimal resource. This study puts in a sincere effort to understand and evaluate the pulmonary nodule when identified by a CT scan. This paper is intended to help the practicing radiologists and also make life easy for a practicing physician to identify correctly the lesions and also help the patients to prevent further progression of the disease. METHODS The study was a cross-sectional study. The sample size of the study consisted of thirty patients. CT scan was done in thirty patients who were identified to have lung nodules either by other mode of radiological studies or first time identified in a CT scan itself. The study was conducted in Fathima Institute of Medical Sciences, Kadapa. The study was conducted from 2014 to 2015. RESULT Non-solid nodules were more in number when compared to the solid nodules. All the non-solid nodules were confirmed to be adenomas. Eighty percent of the nodules which were more than 8 mm in size were confirmed to be malignant. One hundred percent of the spiculated border on CT was confirmed to be malignant. In the present study

  14. Management of an incidentally discovered pulmonary nodule

    International Nuclear Information System (INIS)

    Beigelman-Aubry, Catherine; Hill, Catherine; Grenier, Philippe A.

    2007-01-01

    The incidental finding of a pulmonary nodule on computed tomography (CT) is becoming an increasingly frequent event. The discovery of such a nodule should evoke the possibility of a small bronchogenic carcinoma, for which excision is indicated without delay. However, invasive diagnostic procedures should be avoided in the case of a benign lesion. The objectives of this review article are: (1) to analyze the CT criteria defining benign nodules, nodules of high suspicion of malignancy and indeterminate nodules, (2) to analyze the diagnostic performances and limitations of complementary investigations requested to characterize indeterminate lung nodules, (3) to review the criteria permitting to assess the probability of malignancy of indeterminate nodules and (4) to report on the new guidelines provided by the Fleischner Society for the management of small indeterminate pulmonary nodules, according to their prior probability of malignancy. (orig.)

  15. Report of sodium cavitation

    International Nuclear Information System (INIS)

    Murai, Hitoshi; Shima, Akira; Oba, Toshisaburo; Kobayashi, Ryoji; Hashimoto, Hiroyuki

    1975-01-01

    The damage of components for LMFBRs due to sodium cavitation is serious problem. This report summarizes the following items, (1) mechanism of the incipience of sodium cavitation, (2) damage due to sodium cavitation, (3) detection method for sodium cavitation, and (4) estimation method for sodium cavitation by the comparison with water cavitation. Materials were collected from the reports on liquid metal cavitation, sodium cavitation and water cavitation published from 1965 to now. The mechanism of the incipience of sodium cavitation cavitation parameters (mean location, distributed amount or occurrence aspect and stability), experiment of causing cavitation with Venturi tube, and growth of bubbles within superheated sodium. The sodium cavitation damage was caused by magnetostriction vibration method and with Venturi tube. The state of damage was investigated with the cavitation performance of a sodium pump, and the damage was examined in view of the safety of LMFBR plants. Sodium cavitation was detected with acoustic method, radiation method, and electric method. The effect of physical property of liquid on incipient cavitation was studied. These are thermodynamic effect based on quasistatic thermal equilibrium condition and the effect of the physical property of liquid based on bubble dynamics. (Iwase, T.)

  16. Microbubble Cavitation Imaging

    OpenAIRE

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2013-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information.

  17. Approximations of noise covariance in multi-slice helical CT scans: impact on lung nodule size estimation.

    Science.gov (United States)

    Zeng, Rongping; Petrick, Nicholas; Gavrielides, Marios A; Myers, Kyle J

    2011-10-07

    Multi-slice computed tomography (MSCT) scanners have become popular volumetric imaging tools. Deterministic and random properties of the resulting CT scans have been studied in the literature. Due to the large number of voxels in the three-dimensional (3D) volumetric dataset, full characterization of the noise covariance in MSCT scans is difficult to tackle. However, as usage of such datasets for quantitative disease diagnosis grows, so does the importance of understanding the noise properties because of their effect on the accuracy of the clinical outcome. The goal of this work is to study noise covariance in the helical MSCT volumetric dataset. We explore possible approximations to the noise covariance matrix with reduced degrees of freedom, including voxel-based variance, one-dimensional (1D) correlation, two-dimensional (2D) in-plane correlation and the noise power spectrum (NPS). We further examine the effect of various noise covariance models on the accuracy of a prewhitening matched filter nodule size estimation strategy. Our simulation results suggest that the 1D longitudinal, 2D in-plane and NPS prewhitening approaches can improve the performance of nodule size estimation algorithms. When taking into account computational costs in determining noise characterizations, the NPS model may be the most efficient approximation to the MSCT noise covariance matrix.

  18. Non-invasive Characterization of the Histopathologic Features of Pulmonary Nodules of the Lung Adenocarcinoma Spectrum using Computer Aided Nodule Assessment and Risk Yield (CANARY) – a Pilot Study

    Science.gov (United States)

    Maldonado, Fabien; Boland, Jennifer M.; Raghunath, Sushravya; Aubry, Marie Christine; Bartholmai, Brian J.; deAndrade, Mariza; Hartman, Thomas E.; Karwoski, Ronald A.; Rajagopalan, Srinivasan; Sykes, Anne-Marie; Yang, Ping; Yi, Eunhee S.; Robb, Richard A.; Peikert, Tobias

    2013-01-01

    Introduction Pulmonary nodules of the adenocarcinoma spectrum are characterized by distinctive morphological and radiological features and variable prognosis. Non-invasive high-resolution computed-tomography (HRCT)-based risk stratification tools are needed to individualize their management. Methods Radiological measurements of histopathologic tissue invasion were developed in a training set of 54 pulmonary nodules of the adenocarcinoma spectrum and validated in 86 consecutively resected nodules. Nodules were isolated and characterized by computer-aided analysis and data were analyzed by Spearman correlation, sensitivity, specificity as well as the positive and negative predictive values. Results Computer Aided Nodule Assessment and Risk Yield (CANARY) can non-invasively characterize pulmonary nodules of the adenocarcinoma spectrum. Unsupervised clustering analysis of HRCT data identified 9 unique exemplars representing the basic radiologic building blocks of these lesions. The exemplar distribution within each nodule correlated well with the proportion of histologic tissue invasion, Spearman R=0.87,p < 0.0001 and 0.89,p < 0.0001 for the training and the validation set, respectively. Clustering of the exemplars in three-dimensional space corresponding to tissue invasion and lepidic growth was used to develop a CANARY decision algorithm, which successfully categorized these pulmonary nodules as “aggressive” (invasive adenocarcinoma) or “indolent” (adenocarcinoma in situ and minimally invasive adenocarcinoma). Sensitivity, specificity, positive predictive value and negative predictive value of this approach for the detection of “aggressive” lesions were 95.4%, 96.8%, 95.4% and 96.8%, respectively in the training set and 98.7%, 63.6%, 94.9% and 87.5%, respectively in the validation set. Conclusion CANARY represents a promising tool to non-invasively risk stratify pulmonary nodules of the adenocarcinoma spectrum. PMID:23486265

  19. Diagnosis and management of solitary pulmonary nodules.

    Science.gov (United States)

    Jeong, Yeon Joo; Lee, Kyung Soo; Kwon, O Jung

    2008-12-01

    The advent of computed tomography (CT) screening with or without the help of computer-aided detection systems has increased the detection rate of solitary pulmonary nodules (SPNs), including that of early peripheral lung cancer. Helical dynamic (HD)CT, providing the information on morphologic and hemodynamic characteristics with high specificity and reasonably high accuracy, can be used for the initial assessment of SPNs. (18)F-fluorodeoxyglucose PET/CT is more sensitive at detecting malignancy than HDCT. Therefore, PET/CT may be selectively performed to characterize SPNs when HDCT gives an inconclusive diagnosis. Serial volume measurements are currently the most reliable methods for the tissue characterization of subcentimeter nodules. When malignant nodule is highly suspected for subcentimeter nodules, video-assisted thoracoscopic surgery nodule removal after nodule localization using the pulmonary nodule-marker system may be performed for diagnosis and treatment.

  20. Designing a new CAD system for pulmonary nodule detection in High Resolution Computed Tomography (HRCT images

    Directory of Open Access Journals (Sweden)

    Parsa Hosseini M

    2012-07-01

    Conclusion: Considering the complexity and different shapes of lung nodules and large number of CT images to evaluate, finding lung nodules are difficult and time consuming for physicians and include human error. Experimental results showed the accuracy of the proposed method to be appropriate (P<0.05 for lung nodule detection.

  1. Microbubble Cavitation Imaging

    Science.gov (United States)

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2014-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information. This paper presents a prototype of a 2-D cavitation imager capable of producing images of the dominant cavitation state and activity level in a region of interest. Similar to PCDs, the cavitation imaging described here is based on the spectral analysis of the acoustic signal radiated by the cavitating microbubbles: ultraharmonics of the excitation frequency indicate stable cavitation, whereas elevated noise bands indicate inertial cavitation; the absence of both indicates moderate oscillations. The prototype system is a modified commercially available ultrasound scanner with a sector imaging probe. The lateral resolution of the system is 1.5 mm at a focal depth of 3 cm, and the axial resolution is 3 cm for a therapy pulse length of 20 µs. The maximum frame rate of the prototype is 2 Hz. The system has been used for assessing and mapping the relative importance of the different cavitation states of a microbubble contrast agent. In vitro (tissue-mimicking flow phantom) and in vivo (heart, liver, and brain of two swine) results for cavitation states and their changes as a function of acoustic amplitude are presented. PMID:23549527

  2. Improving the Diagnostic Specificity of CT for Early Detection of Lung Cancer: 4D CT-Based Pulmonary Nodule Elastometry

    Science.gov (United States)

    2015-10-01

    image registration investigation. Int J Radiat Oncol Biol Phys 2009;75:268–75. [13] Liu X, Saboo RR, Pizer SM , Mageras GS. A shape-navigated image...Larson SM , Arbit E. Characterization of neuroblastoma xenograft in rat flank. I. Growth, interstitial fluid pressure, and interstitial fluid velocity...al. Reduced lung-cancer mortality with low- dose computed tomographic screening. N Engl J Med 2011;365:395–409. [27] Maldonado F, Boland JM, Raghunath

  3. Modeling hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.S.; Pandit, A.B. [Mumbai Univ. (India). Chemical Engineering Div.

    1999-12-01

    Cavitation as a source and method of energy input for chemical processing is increasingly studied due to its ability to generate localized high temperatures and pressures under nearly ambient conditions. Compared to cavitation generated by ultrasound, hydrodynamic cavitation has been proved to be a very energy-efficient alternative. A simple and unified model has been developed to study the cavitation phenomena in hydraulic systems with emphasis on the venturi tube and high-speed homogenizer. The model has been found to be satisfactory in explaining the effect of operating variables and equipment geometry on two different modes of cavitation generation qualitatively and in some cases quantitatively. (orig.)

  4. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  5. High-resolution CT in eosinophilic granuloma (histiocytosis X) of the lung

    International Nuclear Information System (INIS)

    Godwin, J.D.; Buschman, D.L.; Moore, A.D.A.; Muller, N.L.; Naidich, D.P.; Carvalho, C.R.R.; Takasugi, J.E.; Schmidt, R.A.

    1988-01-01

    Eosinophilic granuloma of the lung is fascinating but poorly understood. Computed tomographic (CT) scans in 18 cases (11 high resolution) showed a variety of striking patterns: cysts up to 4 cm with thin or indiscernible walls, ranging from a few lesions to confluent honeycombing; retriculonodular infiltrate; and nodules 2 mm-2cm, sometimes cavitated. CT showed that the ill-defined lucencies barely visible on radiographs are indeed cysts, rather than preserved normal lung surrounded by infiltrate. High-resolution CT showed that some of the early, small nodules were concentrated along terminal bronchioles within the secondary lobules. The differential diagnosis includes sarcoidosis and idiopathic fibrosis, but the prominent cystic abnormality and the lack of peripheral concentration help to distinguish eosinophilic granuloma

  6. VATS intraoperative tattooing to facilitate solitary pulmonary nodule resection

    Directory of Open Access Journals (Sweden)

    Boutros Cherif

    2008-03-01

    Full Text Available Abstract Introduction Video-assisted thoracic surgery (VATS has become routine and widely accepted for the removal of solitary pulmonary nodules of unknown etiology. Thoracosopic techniques continue to evolve with better instruments, robotic applications, and increased patient acceptance and awareness. Several techniques have been described to localize peripheral pulmonary nodules, including pre-operative CT-guided tattooing with methylene blue, CT scan guided spiral/hook wire placement, and transthoracic ultrasound. As pulmonary surgeons well know, the lung and visceral pleura may appear featureless on top of a pulmonary nodule. Case description This paper presents a rapid, direct and inexpensive approach to peripheral lung lesion resection by marking the lung parenchyma on top of the nodule using direct methylene blue injection. Methods In two patients with peripherally located lung nodules (n = 3 scheduled for VATS, we used direct methylene blue injection for intraoperative localization of the pulmonary nodule. Our technique was the following: After finger palpation of the lung, a spinal 25 gauge needle was inserted through an existing port and 0.1 ml of methylene blue was used to tattoo the pleura perpendicular to the localized nodule. The methylene blue tattoo immediately marks the lung surface over the nodule. The surgeon avoids repeated finger palpation, while lining up stapler, graspers and camera, because of the visible tattoo. Our technique eliminates regrasping and repalpating the lung once again to identify a non marked lesion. Results Three lung nodules were resected in two patients. Once each lesion was palpated it was marked, and the area was resected with security of accurate localization. All lung nodules were resected in totality with normal lung parenchymal margins. Our technique added about one minute to the operative time. The two patients were discharged home on the second postoperative day, with no morbidity. Conclusion

  7. 3D pulmonary nodules detection using fast marching segmentation ...

    African Journals Online (AJOL)

    This paper proposes an automated computer aided diagnosis system for detection of pulmonary nodules based on three dimensional (3D) structures. Lung ... The proposed detection methodology can give the accuracy of 92%. Keywords: lung cancer; pulmonary nodule; fast marching; 3D features; random forest classifier.

  8. Occurrence of hydrodynamic cavitation.

    Science.gov (United States)

    Nosov, V R; Gómez-Mancilla, J C; Meda-Campaña, J A

    2011-01-01

    In this paper, the conditions under which cavitation (or liquid film rupture) can or cannot occur in thin layers of moving liquid are derived for three typical cases. At the same time, expressions depending on geometrical and movement parameters, where cavitation might start, are given. The results are obtained using simple engineering terms, which can be used in cases whether it is necessary to avoid cavitation or to induce it.

  9. Quantitative assessment of the influence of anatomic noise on the detection of subtle lung nodule in digital chest radiography using fractal-feature distance

    International Nuclear Information System (INIS)

    Imai, Kuniharu; Ikeda, Mitsuru; Enchi, Yukihiro; Niimi, Takanaga

    2008-01-01

    Purpose: To confirm whether or not the influence of anatomic noise on the detection of nodules in digital chest radiography can be evaluated by the fractal-feature distance. Materials and methods: We used the square images with and without a simulated nodule which were generated in our previous observer performance study; the simulated nodule was located on the upper margin of a rib, the inside of a rib, the lower margin of a rib, or the central region between two adjoining ribs. For the square chest images, fractal analysis was conducted using the virtual volume method. The fractal-feature distances between the considered and the reference images were calculated using the pseudo-fractal dimension and complexity, and the square images without the simulated nodule were employed as the reference images. We compared the fractal-feature distances with the observer's confidence level regarding the presence of a nodule in plain chest radiograph. Results: For all square chest images, the relationships between the length of the square boxes and the mean of the virtual volumes were linear on a log-log scale. For all types of the simulated nodules, the fractal-feature distance was the highest for the simulated nodules located on the central region between two adjoining ribs and was the lowest for those located in the inside of a rib. The fractal-feature distance showed a linear relation to an observer's confidence level. Conclusion: The fractal-feature distance would be useful for evaluating the influence of anatomic noise on the detection of nodules in digital chest radiography

  10. Can Cavitation Be Anticipated?

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Dress, W.B.; Hylton, J.O.; Kercel, S.W.

    1999-04-25

    The major problem with cavitation in pumps and hydraulic systems is that there is no effective (conventional) method for detecting or predicting its inception. The traditional method of recognizing cavitation in a pump is to declare the event occurring when the total head drops by some arbitrary value (typically 3%) in response to a pressure reduction at the pump inlet. However, the device is already seriously cavitating when this happens. What is actually needed is a practical method to detect impending rather than incipient cavitation. Whereas the detection of incipient cavitation requires the detection of features just after cavitation starts, the anticipation of cavitation requires the detection and identification of precursor features just before it begins. Two recent advances that make this detection possible. The first is acoustic sensors with a bandwidth of 1 MHz and a dynamic range of 80 dB that preserve the fine details of the features when subjected to coarse vibrations. The second is the application of Bayesian parameter estimation which makes it possible to separate weak signals, such as those present in cavitation precursors, from strong signals, such as pump vibration. Bayesian parameter estimation derives a model based on cavitation hydrodynamics and produces a figure of merit of how well it fits the acquired data. Applying this model to an anticipatory engine should lead to a reliable method of anticipating cavitation before it occurs. This paper reports the findings of precursor features using high-performance sensors and Bayesian analysis of weak acoustic emissions in the 100-1000kHz band from an experimental flow loop.

  11. Hemolytic potential of hydrodynamic cavitation.

    Science.gov (United States)

    Chambers, S D; Bartlett, R H; Ceccio, S L

    2000-08-01

    The purpose of this study was to determine the hemolytic potentials of discrete bubble cavitation and attached cavitation. To generate controlled cavitation events, a venturigeometry hydrodynamic device, called a Cavitation Susceptibility Meter (CSM), was constructed. A comparison between the hemolytic potential of discrete bubble cavitation and attached cavitation was investigated with a single-pass flow apparatus and a recirculating flow apparatus, both utilizing the CSM. An analytical model, based on spherical bubble dynamics, was developed for predicting the hemolysis caused by discrete bubble cavitation. Experimentally, discrete bubble cavitation did not correlate with a measurable increase in plasma-free hemoglobin (PFHb), as predicted by the analytical model. However, attached cavitation did result in significant PFHb generation. The rate of PFHb generation scaled inversely with the Cavitation number at a constant flow rate, suggesting that the size of the attached cavity was the dominant hemolytic factor.

  12. Lung adenocarcinoma mimicking pulmonary fibrosis-a case report

    International Nuclear Information System (INIS)

    Mehić, Bakir; Duranović Rayan, Lina; Bilalović, Nurija; Dohranović Tafro, Danina; Pilav, Ilijaz

    2016-01-01

    Lung cancer is usually presented with cough, dyspnea, pain and weight loss, which is overlapping with symptoms of other lung diseases such as pulmonary fibrosis. Pulmonary fibrosis shows characteristic reticular and nodular pattern, while lung cancers are mostly presented with infiltrative mass, thick-walled cavitations or a solitary nodule with spiculated borders. If the diagnosis is established based on clinical symptoms and CT findings, it would be a misapprehension. We report a case of lung adenocarcinoma whose symptoms as well as clinical images overlapped strongly with pulmonary fibrosis. The patient’s non-productive cough, progressive dyspnea, restrictive pattern of pulmonary function test and CT scans (showing reticular interstitial opacities) were all indicative of pulmonary fibrosis. The patient underwent a treatment consisting of corticosteroids and antibiotics, to no avail. Histopathology of the lung showed that the patient suffered from mucinous adenocarcinoma. Albeit the immunohistochemical staining was not consistent with lung adenocarcinoma, tumor’s morphological characteristics were consistent, and were used to make the definitive diagnosis. Given the fact that radiography cannot always make a clear-cut difference between pulmonary fibrosis and lung adenocarcinomas, and that clinical symptoms often overlap, histological examination should be considered as gold standard for diagnosis of lung adenocarcinoma

  13. Acoustic cavitation studies

    Science.gov (United States)

    Crum, L. A.

    1981-09-01

    The primary thrust of this study was toward a more complete understanding of general aspects of acoustic cavitation. The effect of long-chain polymer additives on the cavitation threshold was investigated to determine if they reduced the acoustic cavitation threshold in a similar manner to the observed reduction in the cavitation index in hydrodynamic cavitation. Measurements were made of the acoustic cavitation threshold as a function of polymer concentration for additives such as guar gum and polyethelene oxide. The measurements were also made as a function of dissolved gas concentration, surface tension and viscosity. It was determined that there was a significant increase in the acoustic cavitation threshold for increased concentrations of the polymer additives (measurable effects could be obtained for concentrations as low as a few parts per million). One would normally expect that an additive that reduces surface tension to decrease the pressure required to cause a cavity to grow and thus these additives, at first thought, should reduce the threshold. However, even in the hydrodynamic case, the threshold was increased. In both of the hydrodynamic cases considered, the explanation for the increased threshold was given in terms of changed fluid dynamics rather than changed physical properties of the fluid.

  14. Fundamentals of Cavitation

    CERN Document Server

    Franc, Jean-Pierre

    2005-01-01

    The present book is aimed at providing a comprehensive presentation of cavitation phenomena in liquid flows. It is further backed up by the experience, both experimental and theoretical, of the authors whose expertise has been internationally recognized. A special effort is made to place the various methods of investigation in strong relation with the fundamental physics of cavitation, enabling the reader to treat specific problems independently. Furthermore, it is hoped that a better knowledge of the cavitation phenomenon will allow engineers to create systems using it positively. Examples in the literature show the feasibility of this approach.

  15. Cavitation damage of ceramics

    International Nuclear Information System (INIS)

    Kovalenko, V.I.; Marinin, V.G.

    1988-01-01

    Consideration is given to results of investigation of ceramic material damage under the effect of cavitation field on their surface, formed in water under the face of exponential concentrator, connected with ultrasonic generator UZY-3-0.4. Amplitude of vibrations of concentrator face (30+-2)x10 -6 m, frequency-21 kHz. It was established that ceramics resistance to cavitation effect correlated with the product of critical of stress intensity factor and material hardness

  16. Subsolid pulmonary nodules: imaging evaluation and strategic management.

    Science.gov (United States)

    Godoy, Myrna C B; Sabloff, Bradley; Naidich, David P

    2012-07-01

    Given the higher rate of malignancy of subsolid pulmonary nodules and the considerably lower growth rate of ground-glass nodules (GGNs), dedicated standardized guidelines for management of these nodules have been proposed, including long-term low-dose computed tomography (CT) follow-up (≥3 years). Physicians must be familiar with the strategic management of subsolid pulmonary nodules, and should be able to identify imaging features that suggest invasive adenocarcinoma requiring a more aggressive management. Low-dose CT screening studies for early detection of lung cancer have increased our knowledge of pulmonary nodules, and in particular our understanding of the strong although imperfect correlation of the subsolid pulmonary nodules, including pure GGNs and part-solid nodules, with the spectrum of preinvasive to invasive lung adenocarcinoma. Serial CT imaging has shown stepwise progression in a subset of these nodules, characterized by increase in size and density of pure GGNs and development of a solid component, the latter usually indicating invasive adenocarcinoma. There is close correlation between the CT features of subsolid nodules (SSNs) and the spectrum of lung adenocarcinoma. Standardized guidelines are suggested for management of SSNs.

  17. Cavitation guide for control valves

    Energy Technology Data Exchange (ETDEWEB)

    Tullis, J.P. [Tullis Engineering Consultants, Logan, UT (United States)

    1993-04-01

    This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation.

  18. Cavitation guide for control valves

    International Nuclear Information System (INIS)

    Tullis, J.P.

    1993-04-01

    This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation

  19. Bacterial lung abscess

    International Nuclear Information System (INIS)

    Groskin, S.A.; Panicek, D.M.; Ewing, D.K.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    A retrospective review of patients with bacterial lung abscess was carried out. Demographic, clinical, and radiographical features of this patient group are compared with similar data from patients with empyema and/or cavitated lung carcinoma; differential diagnostic points are stressed. The entity of radiographically occult lung abscess is discussed. Complications associated with bacterial lung abscess are discussed. Current therapeutic options and treatment philosophy for patients with bacterial lung abscess are noted

  20. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    Cavitation on marine propellers causes thrust breakdown, noise, vibration and erosion. The increasing demand for high-efficiency propellers makes it difficult to avoid the occurrence of cavitation. Currently, practical analysis of propeller cavitation depends on cavitation tunnel test, empirical...... criteria and inviscid flow method, but a series of model test is costly and the other two methods have low accuracy. Nowadays, computational fluid dynamics by using a viscous flow solver is common for practical industrial applications in many disciplines. Cavitation models in viscous flow solvers have been...... hydrofoils and conventional/highly-skewed propellers are performed with one of three cavitation models proven in 2D analysis. 3D cases also show accuracy and robustness of numerical method in simulating steady and unsteady sheet cavitation on complicated geometries. Hydrodynamic characteristics of cavitation...

  1. Solitary pulmonary nodule

    Science.gov (United States)

    ... Adenocarcinoma - chest x-ray Pulmonary nodule - front view chest x-ray Pulmonary nodule, solitary - CT scan Respiratory system References Gotway MB, Panse PM, Gruden JF, Elicker BM. Thoracic radiology: noninvasive diagnostic imaging. In: Broaddus VC, Mason RJ, ...

  2. The influence of inspiratory effort and emphysema on pulmonary nodule volumetry reproducibility.

    Science.gov (United States)

    Moser, J B; Mak, S M; McNulty, W H; Padley, S; Nair, A; Shah, P L; Devaraj, A

    2017-11-01

    To evaluate the impact of inspiratory effort and emphysema on reproducibility of pulmonary nodule volumetry. Eighty-eight nodules in 24 patients with emphysema were studied retrospectively. All patients had undergone volumetric inspiratory and end-expiratory thoracic computed tomography (CT) for consideration of bronchoscopic lung volume reduction. Inspiratory and expiratory nodule volumes were measured using commercially available software. Local emphysema extent was established by analysing a segmentation area extended circumferentially around each nodule (quantified as percent of lung with density of -950 HU or less). Lung volumes were established using the same software. Differences in inspiratory and expiratory nodule volumes were illustrated using the Bland-Altman test. The influences of percentage reduction in lung volume at expiration, local emphysema extent, and nodule size on nodule volume variability were tested with multiple linear regression. The majority of nodules (59/88 [67%]) showed an increased volume at expiration. Mean difference in nodule volume between expiration and inspiration was +7.5% (95% confidence interval: -24.1, 39.1%). No relationships were demonstrated between nodule volume variability and emphysema extent, degree of expiration, or nodule size. Expiration causes a modest increase in volumetry-derived nodule volumes; however, the effect is unpredictable. Local emphysema extent had no significant effect on volume variability in the present cohort. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  3. Cavitation problems in sodium valves

    International Nuclear Information System (INIS)

    Elie, X.

    1976-01-01

    Cavitation poses few problems for sodium valves, in spite of the fact that the loops are not pressurized. This is no doubt due to the low flow velocities in the pipes. For auxiliary loop valves we are attempting to standardize performances with respect to cavitation. For economic reasons cavitation thresholds are approached with large diameter valves. (author)

  4. A novel ultrasonic cavitation enhancer

    NARCIS (Netherlands)

    Rivas, Fernandez D.; Verhaagen, B.; Galdamez Perez, Andres; Castro-Hernandez, Elena; Zwieten, Van Ralph; Schroen, Karin

    2015-01-01

    We introduce a Cavitation Intensifying Bag as a versatile tool for acoustic cavitation control. The cavitation activity is spatially controlled by the modification of the inner surface of the bag with patterned pits of microscopic dimensions. We report on different measurements such as the

  5. A novel ultrasonic cavitation enhancer

    NARCIS (Netherlands)

    Fernandez Rivas, David; Verhaagen, B.; Galdamez Perez, Andres; Castro-Hernandez, Elena; van Zwieten, Ralph; Schroen, Karin

    2015-01-01

    We introduce a Cavitation Intensifying Bag as a versatile tool for acoustic cavitation control. The cavitation activity is spatially controlled by the modification of the inner surface of the bag with patterned pits of microscopic dimensions. We report on different measurements such as the

  6. Advances in intelligent diagnosis methods for pulmonary ground-glass opacity nodules.

    Science.gov (United States)

    Yang, Jing; Wang, Hailin; Geng, Chen; Dai, Yakang; Ji, Jiansong

    2018-02-07

    Pulmonary nodule is one of the important lesions of lung cancer, mainly divided into two categories of solid nodules and ground glass nodules. The improvement of diagnosis of lung cancer has significant clinical significance, which could be realized by machine learning techniques. At present, there have been a lot of researches focusing on solid nodules. But the research on ground glass nodules started late, and lacked research results. This paper summarizes the research progress of the method of intelligent diagnosis for pulmonary nodules since 2014. It is described in details from four aspects: nodular signs, data analysis methods, prediction models and system evaluation. This paper aims to provide the research material for researchers of the clinical diagnosis and intelligent analysis of lung cancer, and further improve the precision of pulmonary ground glass nodule diagnosis.

  7. Cavitated Conglomerate Mass in Silicosis Indicating Associated Tuberculosis

    Directory of Open Access Journals (Sweden)

    Pedro Martins

    2010-01-01

    Full Text Available Silicosis is the most common occupational lung disease worldwide. It leads to respiratory impairment and may have associated infections that decrease pulmonary function. We describe the case of a 55-year-old man with chronic silicosis who presented with hemoptysis and a cavitated conglomerate mass. The final diagnosis was silicotuberculosis.

  8. Harness cavitation to improve processing

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, A.G.; Moholkar, V.S. [Univ. of Bombay (India)

    1996-07-01

    Mention cavitation to most chemical engineers, and they undoubtedly think of it as an operational problem. Indeed, the rapid creation and then collapse of bubbles, which is after all what cavitation involves, can destroy pumps and erode other equipment. Cavitation, however, also can have a positive side--presuming it is designed for and not unplanned. In this article, the authors look at how cavitation can be harnessed to improve processes, and the mechanisms for inducing cavitation--ultrasonics and hydrodynamics--and their likely roles. Sonication, that is, the use of ultrasound, is the conventional approach for creating cavitation, and so they turn to it first. Over the past few years, a number of groups have attempted to solve the problem of scale-up and design of ultrasonic reactors. The authors review the systems that already exist and also explore a simpler and efficient alternative to the ultrasonic reactor, the hydrodynamic cavitation reactor.

  9. Fusariosis as solitary pulmonary nodule

    International Nuclear Information System (INIS)

    Moreno, Nelson; Saavedra R, Alfredo; Sanchez Edgar A

    2008-01-01

    Invasive fungal infections are common cause of morbidity and mortality in immunocompromised patients. Of these the most frequents are: aspergillosis and Fusariosis, both grouped under the term Hyalohyphomycosis. One of the organs most commonly affected is the lung.Unfortunately the clinical manifestations as cough, pain and bleeding pleuritic such are none specific. The chest Rx may show since alveolar infiltration, or nodular lesions until cavitaciones. This is the first report on Colombia of a single pulmonary nodule by Fusarium fungi in an immunocompetent patient.

  10. Transient cavitation in pipelines

    NARCIS (Netherlands)

    Kranenburg, C.

    1974-01-01

    The aim of the present study is to set up a one-dimensional mathematical model, which describes the transient flow in pipelines, taking into account the influence of cavitation and free gas. The flow will be conceived of as a three-phase flow of the liquid, its vapour and non-condensible gas. The

  11. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis.

    Science.gov (United States)

    Nagatani, Yukihiro; Takahashi, Masashi; Murata, Kiyoshi; Ikeda, Mitsuru; Yamashiro, Tsuneo; Miyara, Tetsuhiro; Koyama, Hisanobu; Koyama, Mitsuhiro; Sato, Yukihisa; Moriya, Hiroshi; Noma, Satoshi; Tomiyama, Noriyuki; Ohno, Yoshiharu; Murayama, Sadayuki

    2015-07-01

    To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC curve (AUC) was 0.844 ± 0.017 in ULDCT and 0.876 ± 0.026 in LDCT (p=0.057). For ground glass nodules with LD 8mm or more, LNDP was similar between both methods, as AUC 0.899 ± 0.038 in ULDCT and 0.941 ± 0.030 in LDCT. (p=0.144). ULDCT using AIDR3D with an equivalent radiation dose to chest x-ray could have comparable LNDP to LDCT with AIDR3D except for smaller ground

  12. Correlation between computed tomographic and magnetic resonance imaging findings of parenchymal lung diseases

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Miriam Menna; Rafful, Patricia Piazza [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Rodrigues, Rosana Souza [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); D’Or Institute for Research and Education, Rio de Janeiro, RJ (Brazil); Zanetti, Gláucia [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Hochhegger, Bruno [Complexo Hospitalar Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS (Brazil); Souza, Arthur Soares [Department of Radiology, Medical School of Rio Preto (FAMERP) and Ultra X, São José do Rio Preto, SP (Brazil); Guimarães, Marcos Duarte [Department of Imaging, Hospital AC Camargo, São Paulo, SP (Brazil); Marchiori, Edson, E-mail: edmarchiori@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)

    2013-09-15

    Computed tomography (CT) is considered to be the gold standard method for the assessment of morphological changes in the pulmonary parenchyma. Although its spatial resolution is lower than that of CT, MRI offers the advantage of characterizing different aspects of tissue based on the degree of contrast on T1-weighted image (WI) and T2-WI. In this article, we describe and correlate the MRI and CT features of several common patterns of parenchymal lung disease (air trapping, atelectasis, bronchiectasis, cavitation, consolidation, emphysema, ground-glass opacities, halo sign, interlobular septal thickening, masses, mycetoma, nodules, progressive massive fibrosis, reverse halo sign and tree-in-bud pattern). MRI may be an alternative modality for the collection of morphological and functional information useful for the management of parenchymal lung disease, which would help reduce the number of chest CT scans and radiation exposure required in patients with a variety of conditions.

  13. Mechanism of cavitation damage and structure of a cavitating eddy

    International Nuclear Information System (INIS)

    Efimov, A.V.; Vorob'ev, G.A.; Filenko, Yu.I.; Petrov, K.N.

    1976-01-01

    As a result of experimental studies of the structure of a cavitating eddy and the action of single cavitation bubbles on a solid surface the assumption of double nature of cavitation damage forces depending on its regimes was made. The first type of the damage forces is shock waves, appearing around collapsing spherical bubble, the second type is hydraulic impacts of microjets making a hole in a collapsing aspherical bubble. The outward appearance of single microdents differs from each other. The damage of the first type is accompanied by corrosion. The cavitation erosion intensity of the damage of the first type exceeds that of the damage of the second type by one order of magnitude. The values of the porosity of a cavitation eddy, the bubble concentration and the distance between them, the bubble distribution according to the size and the form for the initial cavitation stage are given from holographic investigations

  14. Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

    Directory of Open Access Journals (Sweden)

    Patricia M. de Groot, MD

    2018-04-01

    Full Text Available Purpose: Precision radiation therapy such as stereotactic body radiation therapy and limited resection are being used more frequently to treat intrathoracic malignancies. Effective local control requires precise radiation target delineation or complete resection. Lung biopsy tracts (LBT on computed tomography (CT scans after the use of tract sealants can mimic malignant tract seeding (MTS and it is unclear whether these LBTs should be included in the calculated tumor volume or resected. This study evaluates the incidence, appearance, evolution, and malignant seeding of LBTs. Methods and materials: A total of 406 lung biopsies were performed in oncology patients using a tract sealant over 19 months. Of these patients, 326 had follow-up CT scans and were included in the study group. Four thoracic radiologists retrospectively analyzed the imaging, and a pathologist examined 10 resected LBTs. Results: A total of 234 of 326 biopsies (72%, including primary lung cancer [n = 98]; metastases [n = 81]; benign [n = 50]; and nondiagnostic [n = 5] showed an LBT on CT. LBTs were identified on imaging 0 to 3 months after biopsy. LBTs were typically straight or serpiginous with a thickness of 2 to 5 mm. Most LBTs were unchanged (92% or decreased (6.3% over time. An increase in LBT thickness/nodularity that was suspicious for MTS occurred in 4 of 234 biopsies (1.7%. MTS only occurred after biopsy of metastases from extrathoracic malignancies, and none occurred in patients with lung cancer. Conclusions: LBTs are common on CT after lung biopsy using a tract sealant. MTS is uncommon and only occurred in patients with extrathoracic malignancies. No MTS was found in patients with primary lung cancer. Accordingly, potential alteration in planned therapy should be considered only in patients with LBTs and extrathoracic malignancies being considered for stereotactic body radiation therapy or wedge resection.

  15. Management of Pulmonary Nodules

    OpenAIRE

    Arvin Aryan

    2010-01-01

    Pulmonary nodule characterization is currently being redefined as new clinical, radiological and pathological data are reported, necessitating a reevaluation of the clinical management."nIn approach to an incidentally detected pulmonary nodule, we should consider that there are different risk situations, different lesion morphologies, and different sizes with various management options."nIn this session we will review the different risk situations for patients with pulmonary nodules...

  16. The usefulness of F-18 FDG PET to discriminate between malignant and benign nodule in idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Kim, Bom Sahn; Kang, Won Jun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2006-01-01

    Incidence of lung cancer in patients with idiopathic pulmonary fibrosis (IPF) is known to be higher than that in general population. However, it is difficult to discriminate pulmonary nodule in patients with IPF, because underlying IPF can be expressed as lung nodules. We evaluated the diagnostic performance of FDG PET in discriminating lung nodule in patients with IPF. We retrospectively reviewed 28 lung nodules in 16 subjects (age; 67.53 ± 9.83, M:F = 14:2). Two patients had previous history of malignant cancer (small cell lung cancer and subglottic cancer). The diagnostic criteria on chest CT were size, morphology and serial changes of size. FDG PET was visually interpreted, and maximal SUV was calculated for quantitative analysis. From 28 nodules, 18 nodules were interpreted as benign nodules, 10 nodules as malignant nodules by histopathology or follow-up chest CT. The sensitivity and specificity of FDG PET were 100% and 94.4%, while those of CT were 70.0% and 44.4% respectively. Malignant nodule was higher maxSUV than that of benign lung nodules (7.68 ± 3.96 vs 1.22 ± 0.65, p < 0.001). Inflammatory lesion in underlying IPF was significantly lower masSUV than that of malignant nodules (1.80 ± 0.43, p < 0.001). The size of malignant and benign nodule were 23.95 ± 10.15 mm and 10.83 ± 5.23 mm p < 0.01) FDG PET showed superior diagnostic performance to chest CT in differentiating lung nodules in patients with underlying IPF. FDG PET could be used to evaluate suspicious malignant nodule detected by chest in patients with IPF

  17. The usefulness of F-18 FDG PET to discriminate between malignant and benign nodule in idiopathic pulmonary fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bom Sahn; Kang, Won Jun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2006-06-15

    Incidence of lung cancer in patients with idiopathic pulmonary fibrosis (IPF) is known to be higher than that in general population. However, it is difficult to discriminate pulmonary nodule in patients with IPF, because underlying IPF can be expressed as lung nodules. We evaluated the diagnostic performance of FDG PET in discriminating lung nodule in patients with IPF. We retrospectively reviewed 28 lung nodules in 16 subjects (age; 67.53 {+-} 9.83, M:F = 14:2). Two patients had previous history of malignant cancer (small cell lung cancer and subglottic cancer). The diagnostic criteria on chest CT were size, morphology and serial changes of size. FDG PET was visually interpreted, and maximal SUV was calculated for quantitative analysis. From 28 nodules, 18 nodules were interpreted as benign nodules, 10 nodules as malignant nodules by histopathology or follow-up chest CT. The sensitivity and specificity of FDG PET were 100% and 94.4%, while those of CT were 70.0% and 44.4% respectively. Malignant nodule was higher maxSUV than that of benign lung nodules (7.68 {+-} 3.96 vs 1.22 {+-} 0.65, p < 0.001). Inflammatory lesion in underlying IPF was significantly lower masSUV than that of malignant nodules (1.80 {+-} 0.43, p < 0.001). The size of malignant and benign nodule were 23.95 {+-} 10.15 mm and 10.83 {+-} 5.23 mm p < 0.01) FDG PET showed superior diagnostic performance to chest CT in differentiating lung nodules in patients with underlying IPF. FDG PET could be used to evaluate suspicious malignant nodule detected by chest in patients with IPF.

  18. Cavitation Generation and Usage Without Ultrasound: Hydrodynamic Cavitation

    Science.gov (United States)

    Gogate, Parag R.; Pandit, Aniruddha B.

    Hydrodynamic Cavitation, which was and is still looked upon as an unavoidable nuisance in the flow systems, can be a serious contender as an alternative to acoustic cavitation for harnessing the spectacular effects of cavitation in physical and chemical processing. The present chapter covers the basics of hydrodynamic cavitation including the considerations for the bubble dynamics analysis, reactor designs and recommendations for optimum operating parameters. An overview of applications in different areas of physical, chemical and biological processing on scales ranging from few grams to several hundred kilograms has also been presented. Since hydrodynamic cavitation was initially proposed as an alternative to acoustic cavitation, it is necessary to compare the efficacy of both these modes of cavitations for a variety of applications and hence comparisons have been discussed either on the basis of energy efficiency or based on the scale of operation. Overall it appears that hydrodynamic cavitation results in conditions similar to those generated using acoustic cavitation but at comparatively much larger scale of operation and with better energy efficiencies.

  19. Micromonospora is a normal occupant of actinorhizal nodules

    Indian Academy of Sciences (India)

    Supplementary table 1. Number of isolates per nodule. Nodule Colonies Average Nodule Colonies Average. AV1 Nodule 1 2 13 EEM Nodule 1 17 9.4. Nodule 2 O Nodule 2 13. Nodule 3 2 Nodule 3 9. AV2 Nodule 1 19 16.1 Nodule 4 7. Nodule 2 25 Nodule 5 18. Nodule 3 38 Nodule 6 4. AV4 Nodule 1 8 14.0 Nodule 7 12.

  20. Quantitative CT: technique dependence of volume estimation on pulmonary nodules

    Science.gov (United States)

    Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Colsher, James; Amurao, Maxwell; Samei, Ehsan

    2012-03-01

    Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.

  1. Surface mechanics design by cavitation peening

    OpenAIRE

    Hitoshi Soyama

    2015-01-01

    Although impacts at cavitation bubble collapses cause severe damage in hydraulic machineries, the cavitation impacts can be utilised for surface mechanics design such as introduction of compressive residual stress and/or improvement of fatigue strength. The peening method using the cavitation impacts was called as cavitation peening. In order to reveal the peening intensity of hydrodynamic cavitation and laser cavitation, the arc height of Almen strip and duralumin plate were measured. In the...

  2. Techniques of Ultrasound Cavitation Control

    Directory of Open Access Journals (Sweden)

    S. P. Skvortsov

    2015-01-01

    Full Text Available The control methods of ultrasonic cavitation applied now within the range from 20 kHz to 80 kHz use either control of ultrasound source parameters (amplitude, acoustic power, etc. or control of one of the cavitation effects (erosion of materials, sonoluminescence, power of acoustic noise, etc.. These methods provide effective management of technological processes, however, make it impossible to relate the estimated effect with parameters of pulsations of cavitation bubbles. This is, mainly, due to influence of a number of uncontrollable parameters, in particular, such as temperature, composition of liquid, gas content, etc. as well as because of the difficulty to establish interrelation between the estimated effect and parameters of pulsations. As a result, in most cases it is difficult to compare controlled parameters of ultrasonic cavitation among themselves, and quantitative characteristics of processes become depending on the type of ultrasonic installation and conditions of their measurement.In this regard, methods to determine parameters of bubble pulsations through sounding a cavitation area by low-intensity laser radiation or to record cavitation noise sub-harmonics reflecting dynamics of changing radius of cavitation bubbles are of interest. The method of optical sounding, via the analysis of spectral components of a scattered signal recorded by a photo-detector, allows us to define a phase of the bubbles collapse with respect to the sound wave and a moving speed of the bubbles wall, as well as to estimate a cavitation index within the light beam section.The method to record sub-harmonicas of cavitation noise allows us to define parameters of pulsations, average for cavitation areas.The above methods allow us both to study mechanisms of cavitation action and to form quantitative criteria of its efficiency based on the physical processes, rather than their consequences and are convenient for arranging a feedback in the units using

  3. Hydrodynamic cavitation for sonochemical effects.

    Science.gov (United States)

    Moholkar, V S; Kumar, P S; Pandit, A B

    1999-03-01

    A comparative study of hydrodynamic and acoustic cavitation has been made on the basis of numerical solutions of the Rayleigh-Plesset equation. The bubble/cavity behaviour has been studied under both acoustic and hydrodynamic cavitation conditions. The effect of varying pressure fields on the collapse of the cavity (sinusoidal for acoustic and linear for hydrodynamic) and also on the latter's dynamic behaviour has been studied. The variations of parameters such as initial cavity size, intensity of the acoustic field and irradiation frequency in the case of acoustic cavitation, and initial cavity size, final recovery pressure and time for pressure recovery in the case of hydrodynamic cavitation, have been found to have significant effects on cavity/bubble dynamics. The simulations reveal that the bubble/cavity collapsing behaviour in the case of hydrodynamic cavitation is accompanied by a large number of pressure pulses of relatively smaller magnitude, compared with just one or two pulses under acoustic cavitation. It has been shown that hydrodynamic cavitation offers greater control over operating parameters and the resultant cavitation intensity. Finally, a brief summary of the experimental results on the oxidation of aqueous KI solution with a hydrodynamic cavitation set-up is given which supports the conclusion of this numerical study. The methodology presented allows one to manipulate and optimise of specific process, either physical or chemical.

  4. Cavitation noise from butterfly valves

    International Nuclear Information System (INIS)

    Rahmeyer, W.J.

    1982-01-01

    Cavitation in valves can produce levels of intense noise. It is possible to mathematically express a limit for a design level of cavitation noise in terms of the cavitation parameter sigma. Using the cavitation parameter or limit, it is then possible to calculate the flow conditions at which a design level of cavitation noise will occur. However, the intensity of cavitation increases with the upstream pressure and valve size at a constant sigma. Therefore, it is necessary to derive equations to correct or scale the cavitation limit for the effects of different upstream pressures and valve sizes. The following paper discusses and presents experimental data for the caviation noise limit as well as the cavitation limits of incipient, critical, incipient damage, and choking cavitation for butterfly valves. The main emphasis is on the design limit of caviation noise, and a noise level of 85 decibels was selected as the noise limit. Tables of data and scaling exponents are included for applying the design limits for the effects of upstream pressure and valve size. (orig.)

  5. CT radiogenomic characterization of EGFR, K-RAS, and ALK mutations in non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Stefania; Rampinelli, Cristiano [European Institute of Oncology, Department of Radiology, Milan (Italy); Petrella, Francesco; Spaggiari, Lorenzo [European Institute of Oncology, Department of Thoracic Surgery, Milan (Italy); Buscarino, Valentina; De Maria, Federica [University of Milan, Department of Health Sciences, Milan (Italy); Raimondi, Sara [European Institute of Oncology, Department of Epidemiology and Biostatistics, Milan (Italy); Barberis, Massimo; Fumagalli, Caterina [European Institute of Oncology, Department of Pathology, Milan (Italy); Spitaleri, Gianluca; De Marinis, Filippo [European Institute of Oncology, Department of Thoracic Oncology, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Department of Radiology, Milan (Italy); University of Milan, Department of Health Sciences, Milan (Italy)

    2016-01-15

    To assess the association between CT features and EGFR, ALK, KRAS mutations in non-small cell lung cancer. Patients undergoing chest CT and testing for the above gene mutations were included. Qualitative evaluation of CTs included: lobe; lesion diameter; shape; margins; ground-glass opacity; density; cavitation; air bronchogram; pleural thickening; intratumoral necrosis; nodules in tumour lobe; nodules in non-tumour lobes; pleural retraction; location; calcifications; emphysema; fibrosis; pleural contact; pleural effusion. Statistical analysis was performed to assess association of features with each gene mutation. ROC curves for gene mutations were drawn; the corresponding area under the curve was calculated. P-values <0.05 were considered significant. Of 285 patients, 60/280 (21.43 %) were positive for EGFR mutation; 31/270 (11.48 %) for ALK rearrangement; 64/240 (26.67 %) for KRAS mutation. EGFR mutation was associated with air bronchogram, pleural retraction, females, non-smokers, small lesion size, and absence of fibrosis. ALK rearrangements were associated with age and pleural effusion. KRAS mutation was associated with round shape, nodules in non-tumour lobes, and smoking. This study disclosed associations between CT features and alterations of EGFR (air bronchogram, pleural retraction, small lesion size, absence of fibrosis), ALK (pleural effusion) and KRAS (round lesion shape, nodules in non-tumour lobes). (orig.)

  6. Cavitation studies in microgravity

    Science.gov (United States)

    Kobel, Philippe; Obreschkow, Danail; Farhat, Mohamed; Dorsaz, Nicolas; de Bosset, Aurele

    The hydrodynamic cavitation phenomenon is a major source of erosion for many industrial systems such as cryogenic pumps for rocket propulsion, fast ship propellers, hydraulic pipelines and turbines. Erosive processes are associated with liquid jets and shockwaves emission fol-lowing the cavity collapse. Yet, fundamental understanding of these processes requires further cavitation studies inside various geometries of liquid volumes, as the bubble dynamics strongly depends the surrounding pressure field. To this end, microgravity represents a unique platform to produce spherical fluid geometries and remove the hydrostatic pressure gradient induced by gravity. The goal of our first experiment (flown on ESA's parabolic flight campaigns 2005 and 2006) was to study single bubble dynamics inside large spherical water drops (having a radius between 8 and 13 mm) produced in microgravity. The water drops were created by a micro-pump that smoothly expelled the liquid through a custom-designed injector tube. Then, the cavitation bubble was generated through a fast electrical discharge between two electrodes immersed in the liquid from above. High-speed imaging allowed to analyze the implications of isolated finite volumes and spherical free surfaces on bubble evolution, liquid jets formation and shock wave dynamics. Of particular interest are the following results: (A) Bubble lifetimes are shorter than in extended liquid volumes, which could be explain by deriving novel corrective terms to the Rayleigh-Plesset equation. (B) Transient crowds of micro-bubbles (smaller than 1mm) appeared at the instants of shockwaves emission. A comparison between high-speed visualizations and 3D N-particle simulations of a shock front inside a liquid sphere reveals that focus zones within the drop lead to a significantly increased density of induced cavitation. Considering shock wave crossing and focusing may hence prove crucially useful to understand the important process of cavitation erosion

  7. Cavitation instabilities in hydraulic machines

    International Nuclear Information System (INIS)

    Tsujimoto, Y

    2013-01-01

    Cavitation instabilities in hydraulic machines, hydro turbines and turbopump inducers, are reviewed focusing on the cause of instabilities. One-dimensional model of hydro turbine system shows that the overload surge is caused by the diffuser effect of the draft tube. Experiments show that this effect also causes the surge mode oscillations at part load. One dimensional model of a cavitating turbopump inducer shows that the mass flow gain factor, representing the cavity volume increase caused by the incidence angle increase is the cause of cavitation surge and rotating cavitation. Two dimensional model of a cavitating turbopump inducer shows that various modes of cavitation instabilities start to occur when the cavity length becomes about 65% of the blade spacing. This is caused by the interaction of the local flow near the cavity trailing edge with the leading edge of the next blade. It was shown by a 3D CFD that this is true also for real cases with tip cavitation. In all cases, it was shown that cavitation instabilities are caused by the fundamental characteristics of cavities that the cavity volume increases with the decrease of ambient pressure or the increase of the incidence angle

  8. Fate of pulmonary nodules detected by computer-aided diagnosis and physician review on the computed tomography simulation images for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Park, Hyo Jung; Kim, Jin Sung; Park, Hee Chul; Oh, Dong Ryul

    2014-01-01

    To investigate the frequency and clinical significance of detected incidental lung nodules found on computed tomography (CT) simulation images for hepatocellular carcinoma (HCC) using computer-aided diagnosis (CAD) and a physician review. Sixty-seven treatment-naive HCC patients treated with transcatheter arterial chemoembolization and radiotherapy (RT) were included for the study. Portal phase of simulation CT images was used for CAD analysis and a physician review for lung nodule detection. For automated nodule detection, a commercially available CAD system was used. To assess the performance of lung nodule detection for lung metastasis, the sensitivity, negative predictive value (NPV), and positive predictive value (PPV) were calculated. Forty-six patients had incidental nodules detected by CAD with a total of 109 nodules. Only 20 (18.3%) nodules were considered to be significant nodules by a physician review. The number of significant nodules detected by both of CAD or a physician review was 24 in 9 patients. Lung metastases developed in 11 of 46 patients who had any type of nodule. The sensitivities were 58.3% and 100% based on patient number and on the number of nodules, respectively. The NPVs were 91.4% and 100%, respectively. And the PPVs were 77.8% and 91.7%, respectively. Incidental detection of metastatic nodules was not an uncommon event. From our study, CAD could be applied to CT simulation images allowing for an increase in detection of metastatic nodules.

  9. Computed tomography-based lung nodule volumetry - do optimized reconstructions of routine protocols achieve similar accuracy, reproducibility and interobserver variability to that of special volumetry protocols?

    International Nuclear Information System (INIS)

    Bolte, H.; Riedel, C.; Knoess, N.; Hoffmann, B.; Heller, M.; Biederer, J.; Freitag, S.

    2007-01-01

    Purpose: The aim of this in vitro and ex vivo CT study was to investigate whether the use of a routine thorax protocol (RTP) with optimized reconstruction parameters can provide comparable accuracy, reproducibility and interobserver variability of volumetric analyses to that of a special volumetry protocol (SVP). Materials and Methods: To assess accuracy, 3 polyurethane (PU) spheres (35 HU; diameters: 4, 6 and 10 mm) were examined with a recommended SVP using a multislice CT (collimation 16 x 0.75 mm, pitch 1.25, 20 mAs, slice thickness 1 mm, increment 0.7 mm, medium kernel) and an optimized RTP (collimation 16 x 1.5 mm, pitch 1.25, 100 mAs, reconstructed slice thickness 2 mm, increment 0.4 mm, sharp kernel). For the assessment of intrascan and interscan reproducibility and interobserver variability, 20 artificial small pulmonary nodules were placed in a dedicated ex vivo chest phantom and examined with identical scan protocols. The artificial lesions consisted of a fat-wax-Lipiodol registered mixture. Phantoms and ex vivo lesions were examined afterwards using commercial volumetry software. To describe accuracy the relative deviations from the true volumes of the PU phantoms were calculated. For intrascan and interscan reproducibility and interobserver variability, the 95 % normal range (95 % NR) of relative deviations between two measurements was calculated. Results: For the SVP the achieved relative deviations for the 4, 6 and 10 mm PU phantoms were - 14.3 %, - 12.7 % and - 6.8 % and were 4.5 %, - 0.6 % and - 2.6 %, respectively, for the optimized RTP. SVP showed a 95 % NR of 0 - 1.5 % for intrascan and a 95 % NR of - 10.8 - 2.9 % for interscan reproducibility. The 95 % NR for interobserver variability was - 4.3 - 3.3 %. The optimized RTP achieved a 95 % NR of - 3.1 - 4.3 % for intrascan reproducibility and a 95 % NR of - 7.0 - 3.5 % for interscan reproducibility. The 95 % NR for interobserver variability was - 0.4 - 6.8 %. (orig.)

  10. Detection of pulmonary nodules

    International Nuclear Information System (INIS)

    Vanzulli, A.; Zanello, A.; DelMaschio, M.; Paesano, P.; Panizza, P.; DelMaschio, A.

    1989-01-01

    The authors have prospectively studied 203 pulmonary nodules in 91 patients, selected by CT (gold standard), with both subtraction digital radiography (SDR) and conventional plain film. Subtracted images were obtained by using copper filter inserted between two photostimulable imaging plates. Five radiologists randomly analyzed all conventional and subtracted images. The authors calculated sensitivity, specificity, and positive and negative predictive values for both conventional radiography and SDR. Receiver operating characteristics (ROC) curves were calculated by plotting the number of nodules detected with different degrees of confidence. SDR detected 12% more nodules than conventional radiography. ROC curves demonstrated that the level of confidence was better for SDR (P <.05)

  11. Dynamic behaviors of cavitation bubble for the steady cavitating flow

    Science.gov (United States)

    Cai, Jun; Huai, Xiulan; Li, Xunfeng

    2009-12-01

    In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a new equation, which does not involve the time term and can describe the motion of cavitation bubble in the steady cavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order method with adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure field downstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (corresponding to the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motion of bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamic behaviors of bubble different from those in previous papers are displayed. In addition, the internal relationship between bubble dynamics and process intensification is also discussed. The simulation results reported in this work reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundation for the practical application of hydrodynamic cavitation technology.

  12. Effects of Different Reconstruction Parameters on CT Volumetric Measurement 
of Pulmonary Nodules

    Directory of Open Access Journals (Sweden)

    Rongrong YANG

    2012-02-01

    Full Text Available Background and objective It has been proven that volumetric measurements could detect subtle changes in small pulmonary nodules in serial CT scans, and thus may play an important role in the follow-up of indeterminate pulmonary nodules and in differentiating malignant nodules from benign nodules. The current study aims to evaluate the effects of different reconstruction parameters on the volumetric measurements of pulmonary nodules in chest CT scans. Methods Thirty subjects who underwent chest CT scan because of indeterminate pulmonary nodules in General Hospital of Tianjin Medical University from December 2009 to August 2011 were retrospectively analyzed. A total of 52 pulmonary nodules were included, and all CT data were reconstructed using three reconstruction algorithms and three slice thicknesses. The volumetric measurements of the nodules were performed using the advanced lung analysis (ALA software. The effects of the reconstruction algorithms, slice thicknesses, and nodule diameters on the volumetric measurements were assessed using the multivariate analysis of variance for repeated measures, the correlation analysis, and the Bland-Altman method. Results The reconstruction algorithms (F=13.6, P<0.001 and slice thicknesses (F=4.4, P=0.02 had significant effects on the measured volume of pulmonary nodules. In addition, the coefficients of variation of nine measurements were inversely related with nodule diameter (r=-0.814, P<0.001. The volume measured at the 2.5 mm slice thickness had poor agreement with the volumes measured at 1.25 mm and 0.625 mm, respectively. Moreover, the best agreement was achieved between the slice thicknesses of 1.25 mm and 0.625 mm using the bone algorithm. Conclusion Reconstruction algorithms and slice thicknesses have significant impacts on the volumetric measurements of lung nodules, especially for the small nodules. Therefore, the reconstruction setting in serial CT scans should be consistent in the follow

  13. Cavitational boiling of liquids

    International Nuclear Information System (INIS)

    Kostyuk, V.V.; Berlin, I.I.; Borisov, N.N.; Karpyshev, A.V.

    1986-01-01

    Transition boiling is a term usually denoting the segment of boiling curve 1-2, where the heat flux, q, decreases as the temperature head, ΔT/sub w/=T/sub w/-T/sub s/, increases. Transition boiling is the subject of numerous papers. Whereas most researchers have studied transition boiling of saturated liquids the authors studied for many years transition boiling of liquids subcooled to the saturation temperature. At high values of subcooling, ΔT/sub sub/=T/sub s/-T/sub 1/, an anomalous dependence of the heat flux density on the temperature head was detected. Unlike a conventional boiling curve, where a single heat flux maximum occurs, another maximum is seen in the transition boiling segment, the boiling being accompanied by strong noise. The authors refer to this kind of boiling as cavitational. This process is largely similar to noisy boiling of helium-II. This article reports experimental findings for cavitational boiling of water, ethanol, freon-113 and noisy boiling of helium-II

  14. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagatani, Yukihiro, E-mail: yatsushi@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Takahashi, Masashi; Murata, Kiyoshi [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Ikeda, Mitsuru [Department of Radiological and Medical Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673, Aichi (Japan); Yamashiro, Tsuneo [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Miyara, Tetsuhiro [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Department of Radiology, Okinawa Prefectural Yaeyama Hospital, Ishigaki 907-0022, Okinawa (Japan); Koyama, Hisanobu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Koyama, Mitsuhiro [Department of Radiology, Osaka Medical College, Takatsuki 569-8686, Osaka (Japan); Sato, Yukihisa [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Department of Radiology, Osaka Medical Center of Cancer and Cardiovascular Diseases, Osaka 537-8511, Osaka (Japan); Moriya, Hiroshi [Department of Radiology, Ohara General Hospital, Fukushima 960-8611 (Japan); Noma, Satoshi [Department of Radiology, Tenri Hospital, Tenri 632-8552, Nara (Japan); Tomiyama, Noriyuki [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Murayama, Sadayuki [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan)

    2015-07-15

    Highlights: • Using AIDR 3D, ULDCT showed comparable LND of solid nodules to LDCT. • Using AIDR 3D, LND of smaller GGN in ULDCT was inferior to that in LDCT. • Effective dose in ULDCT was about only twice of that in chest X-ray. • BMI values in study population were mostly in the normal range body habitus. - Abstract: Purpose: To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). Materials and methods: This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3 mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). Results: For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC

  15. Radiolucencies and cavitation in bronchioloalveolar carcinoma: CT-pathologic correlation

    International Nuclear Information System (INIS)

    Gaeta, M.; Bartiromo, G.; Caruso, R.; Blandino, A.; Scribano, E.; Pandolfo, I.

    1999-01-01

    Bronchioloalveolar carcinoma (BAC) is a polymorphic lung cancer the incidence of which is rising. The presence of intratumoral radiolucencies is an important feature of bronchioloalveolar carcinoma.The aim of this study was to present pictorially the spectrum of intratumoral radiolucencies visible in BAC. In 57 BACs studied with thin-slice CT, we identified six types of radiolucencies: (a) patent intratumoral bronchioles (air bronchiologram); (b) pseudocavitations; (c) cavitation; (d) serpentine radiolucencies; (e) internal alveologram; and (f) multiple cystic lesions. (orig.) (orig.)

  16. Radio-guided thoracoscopic surgery (RGTS) of small pulmonary nodules.

    Science.gov (United States)

    Ambrogi, Marcello Carlo; Melfi, Franca; Zirafa, Carmelina; Lucchi, Marco; De Liperi, Annalisa; Mariani, Giuliano; Fanucchi, Olivia; Mussi, Alfredo

    2012-04-01

    The demand for adequate tissue sampling to determine individual tumor behavior is increasing the number of lung nodule resections, even when the diagnosis is already recognized. Video-assisted thoracic surgery (VATS) is the procedure of choice for diagnosis and treatment of small pulmonary nodules. Difficulties in localizing smaller and deeper nodules have been approached with different techniques. Herein we report our 13-years' experience with radio-guided thoracoscopic resection. Patients with pulmonary nodules smaller than 1 cm and/or deeper than 1 cm, below the visceral pleura, underwent computed tomography (CT)-guided injection of a solution, composed of 0.2 ml (99)Tc-labeled human serum albumin microspheres and 0.1 ml nonionic contrast, into the nodule. During the VATS procedure, an 11-mm-diameter collimated probe connected to a gamma ray detector was introduced to scan the lung surface. The area of major radioactivity, which matched with the area of the nodule, was resected. From 1997 to 2009, 573 patients underwent thoracoscopic resection of small pulmonary nodules, 211 with the radio-guided technique. There were 159 men and 52 women, with an average age of 60.6 years (range = 12-83). The mean duration of the surgical procedure was 41 min (range = 20-100). The procedure was successful in 208/211 cases. Three patients (0.5%) required conversion to a minithoracotomy. The mean length of pleural drainage and hospital stay was 2.3 and 3.7 days, respectively. Histological examination showed 98 benign lesions and 113 malignant lesions (61 metastases and 52 primary lung cancers). This study confirms that radio-guided localization of small pulmonary nodules is a feasible, safe, and quick procedure, with a high rate of success. The spread of the sentinel lymph node technique has increased the availability of technology required for RGTS.

  17. Cavitations synthesis of carbon nanostructures

    International Nuclear Information System (INIS)

    Voropaev, S

    2011-01-01

    Originally an idea of diamonds production by hydrodynamical cavitation was presented by academician E.M. Galimov. He supposed the possibility of nature diamonds formation at fast magma flowing in kimberlitic pipes during bubbles collapse. This hypothesis assumes a number of processes, which were not under consideration until now. It concerns cavitation under high pressure, growth and stability of the gas- and vapors bubbles, their evolution, and corresponding physical- and chemical processes inside. Experimental setup to reproduce the high pressure and temperature reaction centers by means of the cavitation following the above idea was created. A few crystalline nanocarbon forms were successfully recovered after treatment of benzene (C 6 H 6 ).

  18. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    , and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid....... The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model...

  19. Nucleation and cavitation in parahydrogen

    International Nuclear Information System (INIS)

    Pi, Martí; Barranco, Manuel; Navarro, Jesús; Ancilotto, Francesco

    2012-01-01

    Highlights: ► We have constructed a density functional (DF) for parahydrogen between 14 and 32 K. ► The experimental equation of state and the surface tension are well reproduced. ► We have investigated nucleation and cavitations processes in the metastable phase. ► We have obtained the electron bubble explosion within the capillary model. - Abstract: We have used a density functional approach to investigate thermal homogeneous nucleation and cavitation in parahydrogen. The effect of electrons as seeds of heterogeneous cavitation in liquid parahydrogen is also discussed within the capillary model.

  20. Evaluation of pulmonary nodules and lung cancer with one-inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT

    International Nuclear Information System (INIS)

    Moodie, K.; Lau, E.; Hicks, R. J.; Cherk, M. H.; Turlakow, A.; Skinner, S.; Kelly, M. J.; Kalff, V.

    2009-01-01

    Full text: Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d-PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using Nal detectors in coincidence mode (g-PET) have been compared to d-PET but reported usefulness has been variable when gamma cameras with half-inch to three-fourth-inch thick crystals have been used without CT. Our aim was to compare g-PET with a 1-in.-thick crystal and inbuilt CT for lesion localization and attenuation correction (g-PET/CT) and d-PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after 18F-fluorodeoxyglucose (FDG), patients underwent BGO d-PET/CT from jaw to proximal thigh. This was followed by one to two bed position g-PET/CT 194 + 27 min after FDG. Each study pair was independently analysed with concurrent CT. d-PET/CT was interpreted by a radiologist experienced in both PET and CT, and g-PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist, A TNM score was assigned and studies were then unblinded and compared. Fifty-seven patients underwent 58 scan pairs over 2 years. Eighty-nine percent concordance was shown between g-PET/CT and d-PET/CT for the assessment of I intrapulmonary lesions, with 100% concordance for intrapulmonary lesions I >10 mm (36 of 36). Eighty-eight per cent (51 of 58) concordance was shown between g-PET/CTand d-PET/CTforTNM staging. Coincidence imaging usingan optimized dual-head 1-in.-thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some] value when d-PET/CT is not readily available.

  1. Cavitation nuclei measurements - A review

    International Nuclear Information System (INIS)

    Billet, M.L.

    1985-01-01

    The measurement of cavitation nuclei has been the goal of many cavitation research laboratories and has resulted in the development of many methods. Two significantly different approaches have been developed. One is to measure the particulate-microbubble distribution by utilizing acoustical, electrical or optical methods. The other approach measures a liquid tension and a rate of cavitation events for a liquid in order to establish a cavitation susceptibility. Comparisons between various methods indicate that most methods are capable of giving an indication of the nuclei distribution. Measurements obtained in the ocean environment indicate an average of three bubbles per cubic centimeter are present; whereas, water tunnel bubble distributions vary from much less than one to over a hundred per cubic centimeter

  2. Fracture of elastomers by cavitation

    KAUST Repository

    Hamdi, Adel

    2014-01-01

    Cavitation phenomenon is studied in rubber-like materials by combining experimental, theoretical and numerical approaches. Specific tests are carried out on a Styrene Butadiene Rubber to point out main characteristics of cavitation phenomenon. Hydrostatic depression is numerically modelled using finite element method. Numerical results are compared to Ball\\'s and Hou & Abeyaratne\\'s models with regard to cavity nucleation in the material. Both models well fit experimental observations suggesting that the cavitation nucleation in elastomers depends on the confinement degree of the specimen. Finally, critical hydrostatic pressure and critical global deformation are proved to govern cavitation nucleation in the studied material. Critical loadings are identified by comparing experimental and numerical load-displacement curves. © 2013 Elsevier Ltd.

  3. Role of Computer Aided Diagnosis (CAD) in the detection of pulmonary nodules on 64 row multi detector computed tomography.

    Science.gov (United States)

    Prakashini, K; Babu, Satish; Rajgopal, K V; Kokila, K Raja

    2016-01-01

    To determine the overall performance of an existing CAD algorithm with thin-section computed tomography (CT) in the detection of pulmonary nodules and to evaluate detection sensitivity at a varying range of nodule density, size, and location. A cross-sectional prospective study was conducted on 20 patients with 322 suspected nodules who underwent diagnostic chest imaging using 64-row multi-detector CT. The examinations were evaluated on reconstructed images of 1.4 mm thickness and 0.7 mm interval. Detection of pulmonary nodules, initially by a radiologist of 2 years experience (RAD) and later by CAD lung nodule software was assessed. Then, CAD nodule candidates were accepted or rejected accordingly. Detected nodules were classified based on their size, density, and location. The performance of the RAD and CAD system was compared with the gold standard that is true nodules confirmed by consensus of senior RAD and CAD together. The overall sensitivity and false-positive (FP) rate of CAD software was calculated. Of the 322 suspected nodules, 221 were classified as true nodules on the consensus of senior RAD and CAD together. Of the true nodules, the RAD detected 206 (93.2%) and 202 (91.4%) by the CAD. CAD and RAD together picked up more number of nodules than either CAD or RAD alone. Overall sensitivity for nodule detection with the CAD program was 91.4%, and FP detection per patient was 5.5%. The CAD showed comparatively higher sensitivity for nodules of size 4-10 mm (93.4%) and nodules in hilar (100%) and central (96.5%) location when compared to RAD's performance. CAD performance was high in detecting pulmonary nodules including the small size and low-density nodules. CAD even with relatively high FP rate, assists and improves RAD's performance as a second reader, especially for nodules located in the central and hilar region and for small nodules by saving RADs time.

  4. Some Cavitation Properties of Liquids

    Directory of Open Access Journals (Sweden)

    K. D. Efremova

    2016-01-01

    Full Text Available Cavitation properties of liquid must be taken into consideration in the engineering design of hydraulic machines and hydro devices when there is a possibility that in their operation an absolute pressure in the liquid drops below atmospheric one, and for a certain time the liquid is in depression state. Cold boiling, which occurs at a comparatively low temperature under a reduced absolute pressure within or on the surface of the liquid is regarded as hydrostatic cavitation if the liquid is stationary or as hydrodynamic cavitation, if the liquid falls into conditions when in the flow cross-section there is a sharply increasing dynamic pressure and a dropping absolute pressure.In accordance with the theory of cavitation, the first phase of cavitation occurs when the absolute pressure of the degassed liquid drops to the saturated vapour pressure, and the air dissolved in the liquid, leaving the intermolecular space, is converted into micro-bubbles of combined air and becomes a generator of cavitation “nuclei”. A quantitative estimate of the minimum allowable absolute pressure in a real, fully or partially degassed liquid at which a hydrostatic cavitation occurs is of practical interest.Since the pressure of saturated vapour of a liquid is, to a certain extent, related to the forces of intermolecular interaction, it is necessary to have information on the cavitation properties of technical solutions, including air solution in a liquid, as a solute may weaken intermolecular bonds and affect the pressure value of the saturated solvent vapour. In the experiment to carry out vacuum degassing of liquids was used a hydraulic air driven vacuum pump.The paper presents hydrostatic and hydrodynamic degassing liquid processes used in the experiment.The experimental studies of the cavitation properties of technical liquids (sea and distilled water, saturated NaCl solution, and pure glycerol and as a 49/51% solution in water, mineral oil and jet fuel enabled

  5. Benign pulmonary nodule. Morphological features and contrast enhancement evaluated with contiguous thin-section CT

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Hisayasu; Murata, Kiyoshi; Takahashi, Masashi; Morita, Rikushi [Shiga Univ. of Medical Science, Otsu (Japan)

    1998-10-01

    The morphological changes in 54 benign lung nodules, including 8 histologically proven nodules of tuberculoma, 10 of focal organizing pneumonia (FOP), 1 of lung abscess and 35 other benign nodules, were evaluated with contiguous thin-section (3 mm) CT. In addition, incremental dynamic studies were carried out in 25 of these nodules. The three-dimensional shapes of the nodules were found to be quite varied and were classified into four types: round mass (n=18), polygonal mass with concave or straight margins (n=20), oval or band-like mass extending along the bronchovascular bundle (n=7), and oval mass attached to the pleura with broad contact (n=9). Forty-two (78%) of the 54 nodules were located along the bronchovascular bundle. The maximum increments in CT values over 20 HU were observed after contrast enhancement in 18 (72%) of the 25 benign nodules, among which all tuberculomas showed little or no contrast enhancement. The number of small vessels quantified microscopically in the center of the nodules were minimal in tuberculomas with little enhancement and plentiful in lesions of FOP and abscess which showed marked enhancement. Our results suggest that the differentiation between benign and malignant pulmonary nodules is not possible simply on the basis of the degree of contrast enhancement. Therefore, morphological features and the anatomical relation to the bronchovascular bundles should also be taken into consideration in the diagnosis of pulmonary nodules. (author)

  6. Benign pulmonary nodule. Morphological features and contrast enhancement evaluated with contiguous thin-section CT

    International Nuclear Information System (INIS)

    Matsuo, Hisayasu; Murata, Kiyoshi; Takahashi, Masashi; Morita, Rikushi

    1998-01-01

    The morphological changes in 54 benign lung nodules, including 8 histologically proven nodules of tuberculoma, 10 of focal organizing pneumonia (FOP), 1 of lung abscess and 35 other benign nodules, were evaluated with contiguous thin-section (3 mm) CT. In addition, incremental dynamic studies were carried out in 25 of these nodules. The three-dimensional shapes of the nodules were found to be quite varied and were classified into four types: round mass (n=18), polygonal mass with concave or straight margins (n=20), oval or band-like mass extending along the bronchovascular bundle (n=7), and oval mass attached to the pleura with broad contact (n=9). Forty-two (78%) of the 54 nodules were located along the bronchovascular bundle. The maximum increments in CT values over 20 HU were observed after contrast enhancement in 18 (72%) of the 25 benign nodules, among which all tuberculomas showed little or no contrast enhancement. The number of small vessels quantified microscopically in the center of the nodules were minimal in tuberculomas with little enhancement and plentiful in lesions of FOP and abscess which showed marked enhancement. Our results suggest that the differentiation between benign and malignant pulmonary nodules is not possible simply on the basis of the degree of contrast enhancement. Therefore, morphological features and the anatomical relation to the bronchovascular bundles should also be taken into consideration in the diagnosis of pulmonary nodules. (author)

  7. On the computed tomographic diagnosis of pulmonary nodules

    International Nuclear Information System (INIS)

    Higashi, Yuuichirou

    1988-01-01

    Computed tomography (CT) was used to examine 53 pulmonary nodules which were considered not definitely calcified on plain radiographs or conventional tomograms. An average CT number was calculate for each lesion. For the primary lung cancers, the average CT number was 36 HU with a standard deviation of 6.6 HU, while the benign lesions had the mean CT number of 69 HU, with a standard deviation of 42.8 HU. The mean CT number separating lung malignancies from benign lesions was 78.8 HU. To evaluate the attenuation values within each nodule, iso-CT value map was obtained by using Siemens therapy planning system, MEVAPLAN. Nodules were classified into five categories, Type I to V. All of three nodules classified as Type IV were benign. Iso-CT value map was effective in establishing the benignancy of nodules. The quantitative computed tomographic analysis of pulmonary nodules was evaluated by dual-energy CT. Dual-energy CT has the potential to eliminate the effect of spectral hardening by use of monoenergic images derived from dual-kV data and to separate high CT numbers due to calcium from those due to high density organic material. (author)

  8. A Systematic Review of the Prevalence and Pattern of Imaging Defined Post-TB Lung Disease.

    Directory of Open Access Journals (Sweden)

    Jamilah Meghji

    Full Text Available Tuberculosis is an important risk factor for chronic respiratory disease in resource poor settings. The persistence of abnormal spirometry and symptoms after treatment are well described, but the structural abnormalities underlying these changes remain poorly defined, limiting our ability to phenotype post-TB lung disease in to meaningful categories for clinical management, prognostication, and ongoing research. The relationship between post-TB lung damage and patient-centred outcomes including functional impairment, respiratory symptoms, and health related quality of life also remains unclear.We performed a systematic literature review to determine the prevalence and pattern of imaging-defined lung pathology in adults after medical treatment for pleural, miliary, or pulmonary TB disease. Data were collected on study characteristics, and the modality, timing, and findings of thoracic imaging. The proportion of studies relating imaging findings to spirometry results and patient morbidity was recorded. Study quality was assessed using a modified Newcastle-Ottowa score. (Prospero Registration number CRD42015027958.We identified 37 eligible studies. The principle features seen on CXR were cavitation (8.3-83.7%, bronchiectasis (4.3-11.2%, and fibrosis (25.0-70.4%, but prevalence was highly variable. CT imaging identified a wider range of residual abnormalities than CXR, including nodules (25.0-55.8%, consolidation (3.7-19.2%, and emphysema (15.0-45.0%. The prevalence of cavitation was generally lower (7.4-34.6% and bronchiectasis higher (35.0-86.0% on CT vs. CXR imaging. A paucity of prospective data, and data from HIV-infected adults and sub-Saharan Africa (sSA was noted. Few studies related structural damage to physiological impairment, respiratory symptoms, or patient morbidity.Post-TB structural lung pathology is common. Prospective data are required to determine the evolution of this lung damage and its associated morbidity over time. Further

  9. Performance of computer-aided detection of pulmonary nodules in low-dose CT: comparison with double reading by nodule volume

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yingru; Vliegenthart, Rozemarijn; Wang, Ying; Ooijen, Peter M.A. van; Oudkerk, Matthijs [University of Groningen/University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Department of Radiology, P.O. Box 30.001, Groningen (Netherlands); Bock, Geertruida H. de [University of Groningen/University Medical Center Groningen, Department of Epidemiology, P.O. Box 30.001, Groningen (Netherlands); Klaveren, Rob J. van [Lievensberg Hospital, Department of Pulmonology, P.O. Box 135, Bergen op Zoom (Netherlands); Bogoni, Luca [CAD Group, Siemens Medical Solutions USA, Inc., Malvern, PA (United States); Jong, Pim A. de; Mali, Willem P. [University of Utrecht, Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, Utrecht (Netherlands)

    2012-10-15

    To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume. A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two independent readers and processed by CAD. A total of 1,667 findings marked by readers and/or CAD were evaluated by a consensus panel of expert chest radiologists. Performance was evaluated by calculating sensitivity of pulmonary nodule detection and number of false positives, by nodule characteristics and volume. According to the screening protocol, 90.9 % of the findings could be excluded from further evaluation, 49.2 % being small nodules (less than 50 mm{sup 3}). Excluding small nodules reduced false-positive detections by CAD from 3.7 to 1.9 per examination. Of 151 findings that needed further evaluation, 33 (21.9 %) were detected by CAD only, one of them being diagnosed as lung cancer the following year. The sensitivity of nodule detection was 78.1 % for double reading and 96.7 % for CAD. A total of 69.7 % of nodules undetected by readers were attached nodules of which 78.3 % were vessel-attached. CAD is valuable in lung cancer screening to improve sensitivity of pulmonary nodule detection beyond double reading, at a low false-positive rate when excluding small nodules. circle Computer-aided detection (CAD) has known advantages for computed tomography (CT). (orig.)

  10. Performance of computer-aided detection of pulmonary nodules in low-dose CT: comparison with double reading by nodule volume

    International Nuclear Information System (INIS)

    Zhao, Yingru; Vliegenthart, Rozemarijn; Wang, Ying; Ooijen, Peter M.A. van; Oudkerk, Matthijs; Bock, Geertruida H. de; Klaveren, Rob J. van; Bogoni, Luca; Jong, Pim A. de; Mali, Willem P.

    2012-01-01

    To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume. A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two independent readers and processed by CAD. A total of 1,667 findings marked by readers and/or CAD were evaluated by a consensus panel of expert chest radiologists. Performance was evaluated by calculating sensitivity of pulmonary nodule detection and number of false positives, by nodule characteristics and volume. According to the screening protocol, 90.9 % of the findings could be excluded from further evaluation, 49.2 % being small nodules (less than 50 mm 3 ). Excluding small nodules reduced false-positive detections by CAD from 3.7 to 1.9 per examination. Of 151 findings that needed further evaluation, 33 (21.9 %) were detected by CAD only, one of them being diagnosed as lung cancer the following year. The sensitivity of nodule detection was 78.1 % for double reading and 96.7 % for CAD. A total of 69.7 % of nodules undetected by readers were attached nodules of which 78.3 % were vessel-attached. CAD is valuable in lung cancer screening to improve sensitivity of pulmonary nodule detection beyond double reading, at a low false-positive rate when excluding small nodules. circle Computer-aided detection (CAD) has known advantages for computed tomography (CT). (orig.)

  11. Pulmonary nodule characterization, including computer analysis and quantitative features.

    Science.gov (United States)

    Bartholmai, Brian J; Koo, Chi Wan; Johnson, Geoffrey B; White, Darin B; Raghunath, Sushravya M; Rajagopalan, Srinivasan; Moynagh, Michael R; Lindell, Rebecca M; Hartman, Thomas E

    2015-03-01

    Pulmonary nodules are commonly detected in computed tomography (CT) chest screening of a high-risk population. The specific visual or quantitative features on CT or other modalities can be used to characterize the likelihood that a nodule is benign or malignant. Visual features on CT such as size, attenuation, location, morphology, edge characteristics, and other distinctive "signs" can be highly suggestive of a specific diagnosis and, in general, be used to determine the probability that a specific nodule is benign or malignant. Change in size, attenuation, and morphology on serial follow-up CT, or features on other modalities such as nuclear medicine studies or MRI, can also contribute to the characterization of lung nodules. Imaging analytics can objectively and reproducibly quantify nodule features on CT, nuclear medicine, and magnetic resonance imaging. Some quantitative techniques show great promise in helping to differentiate benign from malignant lesions or to stratify the risk of aggressive versus indolent neoplasm. In this article, we (1) summarize the visual characteristics, descriptors, and signs that may be helpful in management of nodules identified on screening CT, (2) discuss current quantitative and multimodality techniques that aid in the differentiation of nodules, and (3) highlight the power, pitfalls, and limitations of these various techniques.

  12. Nodules size: An important factor in nodule mining?

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    A study of about 850 different sized nodules from 234 sites in the Central Indian Basin (CIB) showed a clear inverse relationship between size and grade of nodules. Among the different sized nodules, only the small (less than 2 cm) and medium (2...

  13. Computer-aided detection and automated CT volumetry of pulmonary nodules

    International Nuclear Information System (INIS)

    Marten, Katharina; Engelke, Christoph

    2007-01-01

    With use of multislice computed tomography (MSCT), small pulmonary nodules are being detected in vast numbers, constituting the majority of all noncalcified lung nodules. Although the prevalence of lung cancers among such lesions in lung cancer screening populations is low, their isolation may contribute to increased patient survival. Computer-aided diagnosis (CAD) has emerged as a diverse set of diagnostic tools to handle the large number of images in MSCT datasets and most importantly, includes automated detection and volumetry of pulmonary nodules. Current CAD systems can significantly enhance experienced radiologists' performance and outweigh human limitations in identifying small lesions and manually measuring their diameters, augment observer consistency in the interpretation of such examinations and may thus help to detect significantly higher rates of early malignomas and give more precise estimates on chemotherapy response than can radiologists alone. In this review, we give an overview of current CAD in lung nodule detection and volumetry and discuss their relative merits and limitations. (orig.)

  14. Subtle pulmonary nodules: detection and identification with storage phosphor radiographs and conventional chest films

    International Nuclear Information System (INIS)

    Scheck, R.J.; Schaetzl, M.; Kandziora, C.; Panzer, M.; Rienmueller, R.

    1994-01-01

    To determine the value of digital storagephosphor radiography (SR) on the detection and identification of subtle lung nodules, postero-anterior (PA) and lateral (LAT) film-screen (FR) chest radiographs were compared with isodose SR images of 45 patients with metastatic malignancies. The SR postprocessing was done with a particular mode previously optimized for routine chest radiography. Pulmonary metastases were found in 34 patients and were proved or excluded by CT (n=28) or longterm follow-up FR (n=17). Chest images were divided into four regions for evaluation of image quality, number of lung nodules per region and marked pulmonary structures by receiver-operating characteristics (ROC) analysis (45 patients; 125 nodules; 2810 observations; five readers). Of the nodules selected for an ROC study 82% were 0.5-1.0 cm in diameter. Overall image quality was rated better for FR concerning lung fields (PA) and mediastinum/hilum (LAT). More lung-field nodules were detected on FR than on SR chest images. Use of FR was superior to SR in the general identification of nodules (PA chest), especially concerning intermediate and subtle abnormalities, whereas there was no significant difference for LAT chest images. Our results show, that currently FR still has advantages over SR in the detection and identification of subtle lung nodules in routine clinical radiography. (orig.)

  15. Surface mechanics design by cavitation peening

    Directory of Open Access Journals (Sweden)

    Hitoshi Soyama

    2015-07-01

    Full Text Available Although impacts at cavitation bubble collapses cause severe damage in hydraulic machineries, the cavitation impacts can be utilised for surface mechanics design such as introduction of compressive residual stress and/or improvement of fatigue strength. The peening method using the cavitation impacts was called as cavitation peening. In order to reveal the peening intensity of hydrodynamic cavitation and laser cavitation, the arc height of Almen strip and duralumin plate were measured. In the case of hydrodynamic cavitation, cavitation was generated by injecting a high speed water jet into water with a pressurised chamber and an open chamber, and the cavitating jet in air was also examined. The laser cavitation was produced by a pulse laser, and a high speed observation using a high speed video camera was carried out to clarify laser abrasion and laser cavitation with detecting noise by a hydrophone. It was concluded that the peening intensity by using the cavitating jet in water with the pressurized chamber was most aggressive, and the impact induced by the laser cavitation was larger than that of the laser abrasion at the present condition.

  16. Whole lung computed tomography for detection of pulmonary metastasis of osteosarcoma confirmed at thoracotomy

    International Nuclear Information System (INIS)

    Ishida, Itsuro; Fukuma, Seigo; Sawada, Kinya; Seki, Yasuo; Tanaka, Fumitaka

    1980-01-01

    Whole lung computed tomography (CT) was performed in patients with osteosarcoma of bone to evaluate its diagnostic efficacy in comparison to that in conventional chest radiography and in whole lung tomography to detect metastatic nodules in the lung. In 11 of the 12 patients with osteosarcoma, CT detected pulmonary nodules and in 6 of the 11 patients pulmonary nodules were detected by CT, conventional chest radiography and whole lung tomography, respectively, and 22 pulmonary nodules were resected at thoracotomy and proved to be metastatic lesions. Nineteen nodules of the 22 nodules resected were detected by CT and nine of the 22 nodules were discovered only by CT, while only 10 of 22 nodules were recognized by the conventional chest radiography and the whole lung tomography. Two pulmonary nodules, measuring 1 mm and 2 mm in diameter, respectively, were not detected by any of these three methods. In three nodules that showed to be false positive in CT in the two patients, two nodules were histologically suture granulomas induced by the previous operation, and a deformed protuberance of the chest wall was erroneously interpreted to be a subpleural and intrapulmonary nodule in the remaining. We conclude that CT is the most efficient method to detect pulmonary nodules in the patients with osteosarcoma, but that the minimal size of the detectable nodule by CT is 3 mm in diameter. But a smaller nodule having a tendency to ossify can be detected by CT. (author)

  17. Modeling liquid hydrogen cavitating flow with the full cavitation model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.B.; Qiu, L.M.; Qi, H.; Zhang, X.J.; Gan, Z.H. [Institute of Refrigeration and Cryogenic Engineering, Zhejiang University, Hangzhou 310027 (China)

    2008-12-15

    Cavitation is the formation of vapor bubbles within a liquid where flow dynamics cause the local static pressure to drop below the vapor pressure. This paper strives towards developing an effective computational strategy to simulate liquid hydrogen cavitation relevant to liquid rocket propulsion applications. The aims are realized by performing a steady state computational fluid dynamic (CFD) study of liquid hydrogen flow over a 2D hydrofoil and an axisymmetric ogive in Hord's reports with a so-called full cavitation model. The thermodynamic effect was demonstrated with the assumption of thermal equilibrium between the gas phase and liquid phase. Temperature-dependent fluid thermodynamic properties were specified along the saturation line from the ''Gaspak 3.2'' databank. Justifiable agreement between the computed surface pressure, temperature and experimental data of Hord was obtained. Specifically, a global sensitivity analysis is performed to examine the sensitivity of the turbulent computations to the wall grid resolution, wall treatments and changes in model parameters. A proper near-wall model and grid resolution were suggested. The full cavitation model with default model parameters provided solutions with comparable accuracy to sheet cavitation in liquid hydrogen for the two geometries. (author)

  18. Solitary pulmonary nodule by pulmonary hematoma under warfarin therapy

    International Nuclear Information System (INIS)

    Scheppach, W.; Kulke, H.; Liebau, G.; Braun, H.; Wuerzburg Univ.

    1983-01-01

    Pulmonary hematoma is a rare cause of a pulmonary nodule. Mostly it results from penetrating or blunt chest injuries. The case of a patient is reported, whose chest X-ray showed a pulmonary nodule suspected of malignancy. This patient was maintained permanently on anticoagulants (warfarin derivates) after cardiac valve replacement with a prosthesis. A definite diagnosis could not be established by non-invasive methods. A needle biopsy of the lung was impracticable because of the location of the pulmonary lesion; an exploratory thoracotomy could not be carried out due to a general indication of nonoperability. Control examinations showed that the pulmonary nodule had vanished completely within four months. In consideration of the patient's clinical situation it can be concluded that the pulmonary lesion was caused by a hematoma of the lung. (orig.) [de

  19. Solitary pulmonary nodule by pulmonary hematoma under warfarin therapy

    Energy Technology Data Exchange (ETDEWEB)

    Scheppach, W.; Kulke, H.; Liebau, G.; Braun, H.

    1983-06-01

    Pulmonary hematoma is a rare cause of a pulmonary nodule. Mostly it results from penetrating or blunt chest injuries. The case of a patient is reported, whose chest X-ray showed a pulmonary nodule suspected of malignancy. This patient was maintained permanently on anticoagulants (warfarin derivates) after cardiac valve replacement with a prosthesis. A definite diagnosis could not be established by non-invasive methods. A needle biopsy of the lung was impracticable because of the location of the pulmonary lesion; an exploratory thoracotomy could not be carried out due to a general indication of nonoperability. Control examinations showed that the pulmonary nodule had vanished completely within four months. In consideration of the patient's clinical situation it can be concluded that the pulmonary lesion was caused by a hematoma of the lung.

  20. Numerical and experimental investigations on cavitation erosion

    Science.gov (United States)

    Fortes Patella, R.; Archer, A.; Flageul, C.

    2012-11-01

    A method is proposed to predict cavitation damage from cavitating flow simulations. For this purpose, a numerical process coupling cavitating flow simulations and erosion models was developed and applied to a two-dimensional (2D) hydrofoil tested at TUD (Darmstadt University of Technology, Germany) [1] and to a NACA 65012 tested at LMH-EPFL (Lausanne Polytechnic School) [2]. Cavitation erosion tests (pitting tests) were carried out and a 3D laser profilometry was used to analyze surfaces damaged by cavitation [3]. The method allows evaluating the pit characteristics, and mainly the volume damage rates. The paper describes the developed erosion model, the technique of cavitation damage measurement and presents some comparisons between experimental results and numerical damage predictions. The extent of cavitation erosion was correctly estimated in both hydrofoil geometries. The simulated qualitative influence of flow velocity, sigma value and gas content on cavitation damage agreed well with experimental observations.

  1. Aspergillus infection of the respiratory tract after lung transplantation: chest radiographic and CT findings

    International Nuclear Information System (INIS)

    Diederich, S.; Scadeng, M.; Flower, C.D.R.; Dennis, C.; Stewart, S.

    1998-01-01

    The objective of our study was to assess radiographic and CT findings in lung transplant patients with evidence of Aspergillus colonization or infection of the airways and correlate the findings with clinical, laboratory, bronchoalveolar lavage, biopsy and autopsy findings. The records of 189 patients who had undergone lung transplantation were retrospectively reviewed for evidence of Aspergillus colonization or infection of the airways. Aspergillus was demonstrated by culture or microscopy of sputum or bronchoalveolar lavage fluid or histologically from lung biopsies or postmortem studies in 44 patients (23 %). Notes and radiographs were available for analysis in 30 patients. In 12 of the 30 patients (40 %) chest radiographs remained normal. In 11 of 18 patients with abnormal radiographs pulmonary abnormalities were attributed to invasive pulmonary aspergillosis (IPA) in the absence of other causes for pulmonary abnormalities (8 patients) or because of histological demonstration of IPA (3 patients). In these 11 patients initial radiographic abnormalities were focal areas of patchy consolidation (8 patients), ill-defined pulmonary nodules (2 patients) or a combination of both (1 patient). In some of the lesions cavitation was demonstrated subsequently. At CT a ''halo'' of decreased density was demonstrated in some of the nodules and lesion morphology and location were shown more precisely. Demonstration of Aspergillus from the respiratory tract after lung transplantation does not necessarily reflect IPA but may represent colonization of the airways or semi-invasive aspergillosis. The findings in patients with IPA did not differ from those described in the literature in other immunocompromised patients, suggesting that surgical disruption of lymphatic drainage and nervous supply or effects of preservation and transport of the transplant lung do not affect the radiographic appearances. (orig.)

  2. Experimental research of a microjet cavitation

    Directory of Open Access Journals (Sweden)

    Olšiak Róbert

    2012-04-01

    Full Text Available The paper presents some results of a cavitation research behind a micro-orifice. Investigated were the conditions of the origin of cavitation represented by parameters such as upstream pressure, downstream pressure, liquid temperature and cavitation number. Presented are also images of a cavitating microjet made by the high speed high definition camera RedLake Y3. Dimensions of a microjet are: diameter 0,3 mm; length 0,5 mm.

  3. Correlation of chest computed tomography findings with dyspnea and lung functions in post-tubercular sequelae

    Directory of Open Access Journals (Sweden)

    Ananya Panda

    2016-01-01

    Full Text Available Aims: To study the correlation between dyspnea, radiological findings, and pulmonary function tests (PFTs in patients with sequelae of pulmonary tuberculosis (TB. Materials and Methods: Clinical history, chest computed tomography (CT, and PFT of patients with post-TB sequelae were recorded. Dyspnea was graded according to the Modified Medical Research Council (mMRC scale. CT scans were analyzed for fibrosis, cavitation, bronchiectasis, consolidation, nodules, and aspergilloma. Semi-quantitative analysis was done for these abnormalities. Scores were added to obtain a total morphological score (TMS. The lungs were also divided into three zones and scores added to obtain the total lung score (TLS. Spirometry was done for forced vital capacity (FVC, forced expiratory volume in 1 s (FEV1, and FEV1/FVC. Results: Dyspnea was present in 58/101 patients. A total of 22/58 patients had mMRC Grade 1, and 17/58 patients had Grades 2 and 3 dyspnea each. There was a significant difference in median fibrosis, bronchiectasis, nodules (P < 0.01 scores, TMS, and TLS (P < 0.0001 between dyspnea and nondyspnea groups. Significant correlations were obtained between grades of dyspnea and fibrosis (r = 0.34, P = 0.006, bronchiectasis (r = 0.35, P = 0.004, nodule (r = 0.24, P = 0.016 scores, TMS (r = 0.398, P = 0.000, and TLS (r = 0.35, P = 0.0003. PFTs were impaired in 78/101 (77.2% patients. Restrictive defect was most common in 39.6% followed by mixed in 34.7%. There was a negative but statistically insignificant trend between PFT and fibrosis, bronchiectasis, nodule scores, TMS, and TLS. However, there were significant differences in median fibrosis, cavitation, and bronchiectasis scores in patients with normal, mild to moderate, and severe respiratory defects. No difference was seen in TMS and TLS according to the severity of the respiratory defect. Conclusion: Both fibrosis and bronchiectasis correlated with dyspnea and with PFT. However, this correlation was not

  4. Cavitation erosion in sodium flow, sodium cavitation tunnel testing

    International Nuclear Information System (INIS)

    Courbiere, Pierre.

    1981-04-01

    The high-volume sodium flows present in fast neutron reactors are liable to induce cavitation phenomena in various portion of the sodium lines and pumps. The absence of sufficient data in this area led the C.E.A. to undertake an erosion research program in cavitating sodium flow. This paper discusses the considerations leading to the definition and execution of sodium cavitation erosion tests, and reviews the tests run with 400 0 C sodium on various steel grades: 316, 316 L, 316 Ti (Z8CNDT17-12), Poral (Z3CND18-12), 304 L and LN2 - clad 316 L (Ni coating-clad 316 L). Acoustic detection and signal processing methods were used with an instrument package designed and implemented at the Cadarache Nuclear Research Center

  5. Sonoluminescence and acoustic cavitation

    Science.gov (United States)

    Choi, Pak-Kon

    2017-07-01

    Sonoluminescence (SL) is light emission under high-temperature and high-pressure conditions of a cavitating bubble under intense ultrasound in liquid. In this review, the fundamentals of the interactions between the sound field and the bubble, and between bubbles are explained. Experimental results on high-speed shadowgraphy of bubble dynamics and multibubble SL are shown, demonstrating that the SL intensity is closely related to the bubble dynamics. SL studies of alkali-metal atom (Na and K) emission are summarized. The spectral measurements in solutions with different noble-gas dissolutions and in surfactant solutions, and the results of spatiotemporal separation of SL distribution strongly suggested that the site of alkali-metal atom emission is the gas phase inside bubbles. The spectral studies indicated that alkali-metal atom lines are composed of two kinds of lines: a component that is broadened and shifted from the original D lines arises from van der Waals molecules formed between alkali-metal atoms and noble-gas atoms under extreme conditions at bubble collapse. The other spectral component exhibiting no broadening and no shift was suggested to originate from higher temperature bubbles than those producing the broadened component.

  6. Cavitation and multiphase flow forum - 1985

    International Nuclear Information System (INIS)

    Hoyt, J.W.; Furuya, O.

    1985-01-01

    This book presents the papers given at a conference on fluid flow. Topics considered at the conference included cavitation inception, bubble growth, cavitation noise, holography, axial flow pumps, vortices, cavitation erosion, two-phase flow in nozzles, coal slurry valves, hopper flows of granular materials, helium bubble transport in a closed vertical duct, and a numerical model for flow in a venturi scrubber

  7. Discriminative Localization in CNNs for Weakly-Supervised Segmentation of Pulmonary Nodules.

    Science.gov (United States)

    Feng, Xinyang; Yang, Jie; Laine, Andrew F; Angelini, Elsa D

    2017-09-01

    Automated detection and segmentation of pulmonary nodules on lung computed tomography (CT) scans can facilitate early lung cancer diagnosis. Existing supervised approaches for automated nodule segmentation on CT scans require voxel-based annotations for training, which are labor- and time-consuming to obtain. In this work, we propose a weakly-supervised method that generates accurate voxel-level nodule segmentation trained with image-level labels only. By adapting a convolutional neural network (CNN) trained for image classification, our proposed method learns discriminative regions from the activation maps of convolution units at different scales, and identifies the true nodule location with a novel candidate-screening framework. Experimental results on the public LIDC-IDRI dataset demonstrate that, our weakly-supervised nodule segmentation framework achieves competitive performance compared to a fully-supervised CNN-based segmentation method.

  8. Surgical resection of highly suspicious pulmonary nodules without a tissue diagnosis

    International Nuclear Information System (INIS)

    Heo, Eun-Young; Lee, Kyung-Won; Jheon, Sanghoon; Lee, Jae-Ho; Lee, Choon-Taek; Yoon, Ho-II

    2011-01-01

    The safety and efficacy of surgical resection of lung nodule without tissue diagnosis is controversial. We evaluated direct surgical resection of highly suspicious pulmonary nodules and the clinical and radiological predictors of malignancy. Retrospective analyses were performed on 113 patients who underwent surgical resection without prior tissue diagnosis for highly suspicious pulmonary nodules. Clinical and radiological characteristics were compared between histologically proven benign and malignant nodules after resection. Total costs, length of hospitalization and waiting time to surgery were compared with those of patients who had tissue diagnosis prior to surgery. Among 280 patients with pulmonary nodules suspicious for lung cancer, 113 (40.4%) underwent operation without prior tissue diagnosis. Lung nodules were diagnosed as malignant in 96 (85%) of the 113 patients. Except for forced expiratory volume in 1 s, clinical characteristics were not significantly different according to the pathologic results. Forty-five (90%) of 50 patients with ground-glass opacity nodules had a malignancy. Mixed ground-glass opacity, bubble lucency, irregular margin and larger size correlated with malignancy in ground-glass opacity nodules (P<0.05). Fifty-one (81%) of 67 patients with solid nodules had a malignancy. Spiculation, pre-contrast attenuation and contrast enhancement significantly correlated with malignancy in solid nodules (P<0.05). Surgical resection without tissue diagnosis significantly decreased total costs, hospital stay and waiting time (P<0.05). Direct surgical resection of highly suspicious pulmonary nodules can be a valid procedure. However, careful patient selection and further investigations are required to justify direct surgical resection. (author)

  9. Paediatric CT: the effects of increasing image noise on pulmonary nodule detection

    International Nuclear Information System (INIS)

    Punwani, Shonit; Davies, Warren; Greenhalgh, Rebecca; Humphries, Paul; Zhang, Jie

    2008-01-01

    A radiation dose of any magnitude can produce a detrimental effect manifesting as an increased risk of cancer. Cancer development may be delayed for many years following radiation exposure. Minimizing radiation dose in children is particularly important. However, reducing the dose can reduce image quality and may, therefore, hinder lesion detection. We investigated the effects of reducing the image signal-to-noise ratio (SNR) on CT lung nodule detection for a range of nodule sizes. A simulated nodule was placed at the periphery of the lung on an axial CT slice using image editing software. Multiple copies of the manipulated image were saved with various levels of superimposed noise. The image creation process was repeated for a range of nodule sizes. For a given nodule size, output images were read independently by four Fellows of The Royal College of Radiologists. The overall sensitivities in detecting nodules for the SNR ranges 0.8-0.99, 1-1.49, and 1.5-2.35 were 40.5%, 77.3% and 90.3%, respectively, and the specificities were 47.9%, 73.3% and 75%, respectively. The sensitivity for detecting lung nodules increased with nodule size and increasing SNR. There was 100% sensitivity for the detection of nodules of 4-10 mm in diameter at SNRs greater than 1.5. Reducing medical radiation doses in children is of paramount importance. For chest CT examinations this may be counterbalanced by reduced sensitivity and specificity combined with an increased uncertainty of pulmonary nodule detection. This study demonstrates that pulmonary nodules of 4 mm and greater in diameter can be detected with 100% sensitivity provided that the perceived image SNR is greater than 1.5. (orig.)

  10. Size effects on cavitation instabilities

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2006-01-01

    growth is here analyzed for such cases. A finite strain generalization of a higher order strain gradient plasticity theory is applied for a power-law hardening material, and the numerical analyses are carried out for an axisymmetric unit cell containing a spherical void. In the range of high stress...... triaxiality, where cavitation instabilities are predicted by conventional plasticity theory, such instabilities are also found for the nonlocal theory, but the effects of gradient hardening delay the onset of the instability. Furthermore, in some cases the cavitation stress reaches a maximum and then decays...... as the void grows to a size well above the characteristic material length....

  11. [Role of MRI for detection and characterization of pulmonary nodules].

    Science.gov (United States)

    Sommer, G; Koenigkam-Santos, M; Biederer, J; Puderbach, M

    2014-05-01

    Due to physical and technical limitations, magnetic resonance imaging (MRI) has hitherto played only a minor role in image-based diagnostics of the lungs. However, as a consequence of important methodological developments during recent years, MRI has developed into a technically mature and clinically well-proven method for specific pulmonary questions. The purpose of this article is to provide an overview on the currently available sequences and techniques for assessment of pulmonary nodules and analyzes the clinical significance according to the current literature. The main focus is on the detection of lung metastases, the detection of primary pulmonary malignancies in high-risk individuals and the differentiation between pulmonary nodules of benign and malignant character. The MRI technique has a sensitivity of approximately 80 % for detection of malignant pulmonary nodules compared to the reference standard low-dose computed tomography (CT) and is thus somewhat inferior to CT. Advantages of MRI on the other hand are a higher specificity in differentiating malignant and benign pulmonary nodules and the absence of ionizing radiation exposure. A systematic use of MRI as a primary tool for detection and characterization of pulmonary nodules is currently not recommended due to insufficient data. The diagnostic potential of MRI for early detection and staging of malignant pulmonary diseases, however, seems promising. Therefore, further evaluation of MRI as a secondary imaging modality in clinical trials is highly warranted.

  12. Cavitation instabilities and rotordynamic effects in turbopumps and hydroturbines turbopump and inducer cavitation, experiments and design

    CERN Document Server

    Salvetti, Maria

    2017-01-01

    The book provides a detailed approach to the physics, fluid dynamics, modeling, experimentation and numerical simulation of cavitation phenomena, with special emphasis on cavitation-induced instabilities and their implications on the design and operation of high performance turbopumps and hydraulic turbines. The first part covers the fundamentals (nucleation, dynamics, thermodynamic effects, erosion) and forms of cavitation (attached cavitation, cloud cavitation, supercavitation, vortex cavitation) relevant to hydraulic turbomachinery, illustrates modern experimental techniques for the characterization, visualization and analysis of cavitating flows, and introduces the main aspects of the hydrodynamic design and performance of axial inducers, centrifugal turbopumps and hydo-turbines. The second part focuses on the theoretical modeling, experimental analysis, and practical control of cavitation-induced fluid-dynamic and rotordynamic instabilities of hydraulic turbomachinery, with special emphasis on cavitating...

  13. Lung

    International Nuclear Information System (INIS)

    DeNardo, G.L.; Blankenship, W.J.; Burdine, J.A. Jr.; DeNardo, S.J.

    1975-01-01

    At present no simple statement can be made relative to the role of radionuclidic lung studies in the pediatric population. It is safe to assume that they will be used with increasing frequency for research and clinical applications because of their sensitivity and ready applicability to the pediatric patient. Methods comparable to those used in adults can be used in children older than 4 years. In younger children, however, a single injection of 133 Xe in solution provides an index of both regional perfusion and ventilation which is easier to accomplish. This method is particularly valuable in infants and neonates because it is rapid, requires no patient cooperation, results in a very low radiation dose, and can be repeated in serial studies. Radionuclidic studies of ventilation and perfusion can be performed in almost all children if the pediatrician and the nuclear medicine specialist have motivation and ingenuity. S []ontaneous pulmonary vascular occlusive disease which occurs in infants and pulmonary emboli in children are easily detected using radionuclides. The pathophysiologic defects of pulmonary agenesis, bronchopulmonary sequestration, and foreign body aspiration may be demonstrated by these techniques. These techniques also appear to be useful in following patients with bronchial asthma, cystic fibrosis, congenital emphysema, and postinfection pulmonary abnormalities. (auth)

  14. A theoretical study of hydrodynamic cavitation.

    Science.gov (United States)

    Arrojo, S; Benito, Y

    2008-03-01

    The optimization of hydrodynamic cavitation as an AOP requires identifying the key parameters and studying their effects on the process. Specific simulations of hydrodynamic bubbles reveal that time scales play a major role on the process. Rarefaction/compression periods generate a number of opposing effects which have demonstrated to be quantitatively different from those found in ultrasonic cavitation. Hydrodynamic cavitation can be upscaled and offers an energy efficient way of generating cavitation. On the other hand, the large characteristic time scales hinder bubble collapse and generate a low number of cavitation cycles per unit time. By controlling the pressure pulse through a flexible cavitation chamber design these limitations can be partially compensated. The chemical processes promoted by this technique are also different from those found in ultrasonic cavitation. Properties such as volatility or hydrophobicity determine the potential applicability of HC and therefore have to be taken into account.

  15. Stochastic-field cavitation model

    International Nuclear Information System (INIS)

    Dumond, J.; Magagnato, F.; Class, A.

    2013-01-01

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian “particles” or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations

  16. Stochastic-field cavitation model

    Science.gov (United States)

    Dumond, J.; Magagnato, F.; Class, A.

    2013-07-01

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian "particles" or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

  17. In Vivo Microbubble Cavitation Imaging

    NARCIS (Netherlands)

    Vignon, F.; Shi, W.; Liu, J.; Xie, F.; Gao, S.; Drvol, L.; Lof, J.; Everbach, C.; Porter, T.; Powers, J.

    2011-01-01

    Stroke is the second cause of death and leading cause of disabilityworldwide. Less than 5% of ischemic stroke patients receive the state-of-the art treatment of a thrombolytic drug tPA, and only about 10% of these gain additional benefit from it. Ultrasound (US)-inducedmicrobubble (MB) cavitation

  18. Level-set segmentation of pulmonary nodules in megavolt electronic portal images using a CT prior

    International Nuclear Information System (INIS)

    Schildkraut, J. S.; Prosser, N.; Savakis, A.; Gomez, J.; Nazareth, D.; Singh, A. K.; Malhotra, H. K.

    2010-01-01

    Purpose: Pulmonary nodules present unique problems during radiation treatment due to nodule position uncertainty that is caused by respiration. The radiation field has to be enlarged to account for nodule motion during treatment. The purpose of this work is to provide a method of locating a pulmonary nodule in a megavolt portal image that can be used to reduce the internal target volume (ITV) during radiation therapy. A reduction in the ITV would result in a decrease in radiation toxicity to healthy tissue. Methods: Eight patients with nonsmall cell lung cancer were used in this study. CT scans that include the pulmonary nodule were captured with a GE Healthcare LightSpeed RT 16 scanner. Megavolt portal images were acquired with a Varian Trilogy unit equipped with an AS1000 electronic portal imaging device. The nodule localization method uses grayscale morphological filtering and level-set segmentation with a prior. The treatment-time portion of the algorithm is implemented on a graphical processing unit. Results: The method was retrospectively tested on eight cases that include a total of 151 megavolt portal image frames. The method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases. The treatment phase portion of the method has a subsecond execution time that makes it suitable for near-real-time nodule localization. Conclusions: A method was developed to localize a pulmonary nodule in a megavolt portal image. The method uses the characteristics of the nodule in a prior CT scan to enhance the nodule in the portal image and to identify the nodule region by level-set segmentation. In a retrospective study, the method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases studied.

  19. Towards the concept of hydrodynamic cavitation control

    Science.gov (United States)

    Chatterjee, Dhiman; Arakeri, Vijay H.

    1997-02-01

    A careful study of the existing literature available in the field of cavitation reveals the potential of ultrasonics as a tool for controlling and, if possible, eliminating certain types of hydrodynamic cavitation through the manipulation of nuclei size present in a flow. A glass venturi is taken to be an ideal device to study the cavitation phenomenon at its throat and its potential control. A piezoelectric transducer, driven at the crystal resonant frequency, is used to generate an acoustic pressure field and is termed an ‘ultrasonic nuclei manipulator (UNM)’. Electrolysis bubbles serve as artificial nuclei to produce travelling bubble cavitation at the venturi throat in the absence of a UNM but this cavitation is completely eliminated when a UNM is operative. This is made possible because the nuclei, which pass through the acoustic field first, cavitate, collapse violently and perhaps fragment and go into dissolution before reaching the venturi throat. Thus, the potential nuclei for travelling bubble cavitation at the venturi throat seem to be systematically destroyed through acoustic cavitation near the UNM. From the solution to the bubble dynamics equation, it has been shown that the potential energy of a bubble at its maximum radius due to an acoustic field is negligible compared to that for the hydrodynamic field. Hence, even though the control of hydrodynamic macro cavitation achieved in this way is at the expense of acoustic micro cavitation, it can still be considered to be a significant gain. These are some of the first results in this direction.

  20. Benign metastasizing leiomyoma presenting as multiple cystic pulmonary nodules: a case report.

    Science.gov (United States)

    Choe, Yeong Hun; Jeon, So Yeon; Lee, Yoon Chae; Chung, Myung Ja; Park, Seung Yong; Lee, Yong Chul; Kim, So Ri

    2017-09-12

    Benign metastatic leiomyoma (BML) is an extremely rare disease. Although uterine leiomyomas are benign histologically, they can metastasize to distant sites. While the incidence is very low, the lung is the organ most frequently affected by BML. Pulmonary BML usually presents as numerous well-defined nodules of various sizes, while the cavitary or cystic features in the nodules are rarely observed on radiologic images. A 52-year-old woman complained of cough and dyspnea for one month. She had been previously diagnosed with uterine leiomyoma and had undergone total hysterectomy about 14 years prior. High-resolution computed tomography (CT) images showed that there were multiple cystic nodules of various sizes in both lungs. Pathologic examination revealed that the pulmonary nodule had complex branching glandular structures lined by a single layer of simple cuboidal to columnar epithelium that was surrounded by abundant spindle cells. Additional immunohistochemistry data suggested that pulmonary nodule diagnosis was BML-associated uterine leiomyoma. In this report, we introduce an interesting case of pulmonary BML that presented as a combination of various kinds of nodules including simple round nodules, simple cysts, and cysts with a solid portion, which are very rare radiologic features of BML in lung. In addition, when the patient is a woman of reproductive age, physicians should meticulously review the gynecological history and suspect BML when there are various cystic pulmonary lesions.

  1. Radiolucencies and cavitation in bronchioloalveolar carcinoma: CT-pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Gaeta, M.; Bartiromo, G. [Service of Diagnostic Imaging, Piemonte Hospital, Messina (Italy); Caruso, R. [Institute of Pathology, University of Messina (Italy); Blandino, A.; Scribano, E.; Pandolfo, I. [Institute of Radiologic Sciences, University of Messina (Italy)

    1999-02-01

    Bronchioloalveolar carcinoma (BAC) is a polymorphic lung cancer the incidence of which is rising. The presence of intratumoral radiolucencies is an important feature of bronchioloalveolar carcinoma.The aim of this study was to present pictorially the spectrum of intratumoral radiolucencies visible in BAC. In 57 BACs studied with thin-slice CT, we identified six types of radiolucencies: (a) patent intratumoral bronchioles (air bronchiologram); (b) pseudocavitations; (c) cavitation; (d) serpentine radiolucencies; (e) internal alveologram; and (f) multiple cystic lesions. (orig.) (orig.) With 12 figs., 13 refs.

  2. Cavitation nucleation in gelatin: Experiment and mechanism.

    Science.gov (United States)

    Kang, Wonmo; Adnan, Ashfaq; O'Shaughnessy, Thomas; Bagchi, Amit

    2018-02-01

    Dynamic cavitation in soft materials is becoming increasingly relevant due to emerging medical implications such as the potential of cavitation-induced brain injury or cavitation created by therapeutic medical devices. However, the current understanding of dynamic cavitation in soft materials is still very limited, mainly due to lack of robust experimental techniques. To experimentally characterize cavitation nucleation under dynamic loading, we utilize a recently developed experimental instrument, the integrated drop tower system. This technique allows quantitative measurements of the critical acceleration (a cr ) that corresponds to cavitation nucleation while concurrently visualizing time evolution of cavitation. Our experimental results reveal that a cr increases with increasing concentration of gelatin in pure water. Interestingly, we have observed the distinctive transition from a sharp increase (pure water to 1% gelatin) to a much slower rate of increase (∼10× slower) between 1% and 7.5% gelatin. Theoretical cavitation criterion predicts the general trend of increasing a cr , but fails to explain the transition rates. As a likely mechanism, we consider concentration-dependent material properties and non-spherical cavitation nucleation sites, represented by pre-existing bubbles in gels, due to possible interplay between gelatin molecules and nucleation sites. This analysis shows that cavitation nucleation is very sensitive to the initial configuration of a bubble, i.e., a non-spherical bubble can significantly increase a cr . This conclusion matches well with the experimentally observed liquid-to-gel transition in the critical acceleration for cavitation nucleation. From a medical standpoint, understanding dynamic cavitation within soft materials, i.e., tissues, is important as there are both potential injury implications (blast-induced cavitation within the brain) as well as treatments utilizing the phenomena (lithotripsy). In this regard, the main

  3. Cavitation noise studies on marine propellers

    Science.gov (United States)

    Sharma, S. D.; Mani, K.; Arakeri, V. H.

    1990-04-01

    Experimental observations are described of cavitation inception and noise from five model propellers, three basic and two modified, tested in the open jet section of the Indian Institute of Science high-speed water tunnel facility. Extensive experiments on the three basic propellers of different design, which included visualization of cavitation and measurements of noise, showed that the dominant type of cavitation was in the form of tip vortex cavitation, accompanied by leading edge suction side sheet cavitation in its close vicinity, and the resultant noise depended on parameters such as the advance coefficient, the cavitation number, and the propeller geometry. Of these, advance coefficient was found to have the maximum influence not only on cavitation noise but also on the inception of cavitation. Noise levels and frequencies of spectra obtained from all the three basic propellers at conditions near inception and different advance coefficient values, when plotted in the normalized form as suggested by Blake, resulted in a universal spectrum which would be useful for predicting cavitation noise at prototype scales when a limited extent of cavitation is expected in the same form as observed on the present models. In an attempt to delay the onset of tip vortex cavitation, the blades of two of the three basic propellers were modified by drilling small holes in the tip and leading edge areas. Studies on the modified propellers showed that the effectiveness of the blade modification was apparently stronger at low advance coefficient values and depended on the blade sectional profile. Measurements of cavitation noise indicated that the modification also improved the acoustic performance of the propellers as it resulted in a complete attenuation of the low-frequency spectral peaks, which were prominent with the basic propellers. In addition to the above studies, which were conducted under uniform flow conditions, one of the basic propellers was tested in the simulated

  4. Mucoid impaction presenting as multiple pulmonary nodules in cystic fibrosis

    International Nuclear Information System (INIS)

    Carpenter, L.D.; Lambie, N.K.; Wilsher, M.L.

    1996-01-01

    Mucoid impaction has been described as a complication of asthma and more commonly in patients with allergic bronchopulmonary aspergillosis. In such cases, the impacted pools of mucus may present as discrete nodules on chest X-ray and hence simulate the appearance of metastatic malignancy. A case of mucoid impaction presenting as multiple pulmonary nodules in a patient with cystic fibrosis is described. The chest X-ray showed hyperinfiltration and scattered changes consistent with bronchiectasis. Computed tomography scan confirmed these and additional intra-pulmonary nodular densities. This report illustrates that mucus impaction as a cause of pulmonary nodules should be considered in any patient with chronic lung disease characterised by excess mucus production. 6 refs., 3 figs

  5. Pump cavitation and inducer design

    International Nuclear Information System (INIS)

    Heslenfeld, M.W.; Hes, M. de

    2002-01-01

    Details of past work on sodium pump development and cavitation studies executed mainly for SNR 300 were reported earlier. Among the requirements for large sodium pumps are long life (200000 hours up to 300000 hours) and small size of impeller and pump, fully meeting the process and design criteria. These criteria are the required 'Q, H, r characteristics' in combination with a low NPSH value and the avoidance of cavitation damage to the pump. The pump designer has to develop a sound hydraulic combination consisting of suction arrangement, impeller design and diffuser. On the other hand the designer is free to choose an optimal pump speed. The pump speed in its turn influences the rotor dynamic pump design and the pump drive. The introduction of the inducer as an integral part of the pump design is based on following advantages: no tip cavitation; (possible) cavitation bubbles move to the open centre due to centrifugal forces on the fluid; the head of the inducer improves the inlet conditions of the impeller. The aim of an inducer is the increase in the suction specific speed (SA value) of a pump whereby the inducer functions as a pressure source improving the impeller inlet conditions. With inducer-impeller combinations values up to SA=15000 are realistic. With the use of an inducer the overall pump sizes can be reduced with Ca. 30%. Pumps commonly available have SA values up to a maximum of ca. 10000. A development programme was executed for SNR 300 in order to reach an increase of the suction specific speed of the impeller from SA 8200 to SA 11000. Further studies to optimize pumps design for the follow up line introduced the 'inducer acting as a pre-impeller' development. This programme was executed in the period 1979-1981. At the FDO premises a scale 1 2.8 inducer impeller combination with a suction specific speed SA=15000 was developed, constructed and tested at the water test rig. This water test rig is equipped with a perspex pipe allowing also visualisation

  6. Scale effect on bubble growth and cavitation inception in cavitation susceptibility meters

    International Nuclear Information System (INIS)

    Shen, Y.T.; Gowing, S.

    1985-01-01

    The Reynolds number alone is not adequate to predict cavitation inception scaling. Recent experiments on headforms once again show that the cavitation inception data are very sensitive to the nuclei tensile strength which, in turn depends on the velocity scale. This paper theoretically investigates the influence of Reynolds number and velocity scale on cavitation inception in a cavitation susceptibility meter. The numerical examples given are based on a single bubble spherical model

  7. Nodule detection methods using autocorrelation features on 3D chest CT scans

    International Nuclear Information System (INIS)

    Hara, T.; Zhou, X.; Okura, S.; Fujita, H.; Kiryu, T.; Hoshi, H.

    2007-01-01

    Lung cancer screening using low dose X-ray CT scan has been an acceptable examination to detect cancers at early stage. We have been developing an automated detection scheme for lung nodules on CT scan by using second-order autocorrelation features and the initial performance for small nodules (< 10 mm) shows a high true-positive rate with less than four false-positive marks per case. In this study, an open database of lung images, LIDC (Lung Image Database Consortium), was employed to evaluate our detection scheme as an consistency test. The detection performance for solid and solitary nodules in LIDC, included in the first data set opened by the consortium, was 83% (10/12) true-positive rate with 3.3 false-positive marks per case. (orig.)

  8. Cavitation erosion - scale effect and model investigations

    Science.gov (United States)

    Geiger, F.; Rutschmann, P.

    2015-12-01

    The experimental works presented in here contribute to the clarification of erosive effects of hydrodynamic cavitation. Comprehensive cavitation erosion test series were conducted for transient cloud cavitation in the shear layer of prismatic bodies. The erosion pattern and erosion rates were determined with a mineral based volume loss technique and with a metal based pit count system competitively. The results clarified the underlying scale effects and revealed a strong non-linear material dependency, which indicated significantly different damage processes for both material types. Furthermore, the size and dynamics of the cavitation clouds have been assessed by optical detection. The fluctuations of the cloud sizes showed a maximum value for those cavitation numbers related to maximum erosive aggressiveness. The finding suggests the suitability of a model approach which relates the erosion process to cavitation cloud dynamics. An enhanced experimental setup is projected to further clarify these issues.

  9. Sound source location in cavitating tip vortices

    International Nuclear Information System (INIS)

    Higuchi, H.; Taghavi, R.; Arndt, R.E.A.

    1985-01-01

    Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress

  10. Cavitation occurrence around ultrasonic dental scalers

    OpenAIRE

    Felver, Bernhard; King, David C; Lea, Simon C; Price, Gareth J; Damien Walmsley, A

    2009-01-01

    Ultrasonic scalers are used in dentistry to remove calculus and other contaminants from teeth. One mechanism which may assist in the cleaning is cavitation generated in cooling water around the scaler. The vibratory motion of three designs of scaler tip in a water bath has been characterised by laser vibrometry, and compared with the spatial distribution of cavitation around the scaler tips observed using sonochemiluminescence from a luminol solution. The type of cavitation was confirmed by a...

  11. Contributions to some cavitation problems in turbomachinery

    OpenAIRE

    Arakeri, VH

    1999-01-01

    In the present article, three problems associated with cavitation in turbomachinery are discussed. The first one deals with the potential application of recent understanding in cavitation inception to similar problems in turbomachinery. The second considers the thermodynamic effects in developed cavitation. This has relevance to turbopump operation using fluids other than water. Old correlations to predict the above effect are summarized and a new correlation is proposed. Lastly, the possible...

  12. Cavitation Nuclei: Experiments and Theory

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2009-01-01

    The Swedish astrophysicist and Nobel Prize winner Hannes Alfven said: Theories come and go - the experiment is here forever. Often a theory, which we set up to describe an observed physical phenomenon, suffers from the lack of knowledge of decisive parameters, and therefore at best the theory...... becomes insufficient. Contrary, the experiment always reveals nature itself, though at prevailing experimental conditions. With essential parameters being out of control and even maybe unidentified, apparently similar experiments may deviate way beyond our expectations. However, these discrepancies offer...... us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

  13. Disintegration of materials by cavitating microjets

    Directory of Open Access Journals (Sweden)

    Mlkvik M.

    2013-04-01

    Full Text Available In the paper is presented an investigation of material disintegration by cavitating microjets. Cavitating microjet develops behind the micro-orifice at high flow speeds, when local pressure drop initiates a cavitation phenomenon. Described is a method and presented are selected results of experiments. Experiments were carried out with 2 micro-orifices at different flow conditions (cavitation number, distance between sample and micro-orifice. Experiments are based on flow visualisation as well as on a character of material displacement.

  14. A Comparison of Two Commercial Volumetry Software Programs in the Analysis of Pulmonary Ground-Glass Nodules: Segmentation Capability and Measurement Accuracy

    Science.gov (United States)

    Kim, Hyungjin; Lee, Sang Min; Lee, Hyun-Ju; Goo, Jin Mo

    2013-01-01

    Objective To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. Materials and Methods In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. Results The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. Conclusion LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs. PMID:23901328

  15. A comparison of two commercial volumetry software programs in the analysis of pulmonary ground-glass nodules: Segmentation capability and measurement accuracy

    International Nuclear Information System (INIS)

    Kim, Hyung Jin; Park, Chang Min; Lee, Sang Min; Lee, Hyun Joo; Goo, Jin Mo

    2013-01-01

    To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs.

  16. A comparison of two commercial volumetry software programs in the analysis of pulmonary ground-glass nodules: Segmentation capability and measurement accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Jin; Park, Chang Min; Lee, Sang Min; Lee, Hyun Joo; Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2013-08-15

    To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs.

  17. Local pulmonary structure classification for computer-aided nodule detection

    Science.gov (United States)

    Bahlmann, Claus; Li, Xianlin; Okada, Kazunori

    2006-03-01

    We propose a new method of classifying the local structure types, such as nodules, vessels, and junctions, in thoracic CT scans. This classification is important in the context of computer aided detection (CAD) of lung nodules. The proposed method can be used as a post-process component of any lung CAD system. In such a scenario, the classification results provide an effective means of removing false positives caused by vessels and junctions thus improving overall performance. As main advantage, the proposed solution transforms the complex problem of classifying various 3D topological structures into much simpler 2D data clustering problem, to which more generic and flexible solutions are available in literature, and which is better suited for visualization. Given a nodule candidate, first, our solution robustly fits an anisotropic Gaussian to the data. The resulting Gaussian center and spread parameters are used to affine-normalize the data domain so as to warp the fitted anisotropic ellipsoid into a fixed-size isotropic sphere. We propose an automatic method to extract a 3D spherical manifold, containing the appropriate bounding surface of the target structure. Scale selection is performed by a data driven entropy minimization approach. The manifold is analyzed for high intensity clusters, corresponding to protruding structures. Techniques involve EMclustering with automatic mode number estimation, directional statistics, and hierarchical clustering with a modified Bhattacharyya distance. The estimated number of high intensity clusters explicitly determines the type of pulmonary structures: nodule (0), attached nodule (1), vessel (2), junction (>3). We show accurate classification results for selected examples in thoracic CT scans. This local procedure is more flexible and efficient than current state of the art and will help to improve the accuracy of general lung CAD systems.

  18. Automatic detection of pulmonary nodules at spiral CT: clinical application of a computer-aided diagnosis system

    International Nuclear Information System (INIS)

    Wormanns, Dag; Fiebich, Martin; Saidi, Mustafa; Diederich, Stefan; Heindel, Walter

    2002-01-01

    The aim of this study was to evaluate a computer-aided diagnosis (CAD) workstation with automatic detection of pulmonary nodules at low-dose spiral CT in a clinical setting for early detection of lung cancer. Eighty-eight consecutive spiral-CT examinations were reported by two radiologists in consensus. All examinations were reviewed using a CAD workstation with a self-developed algorithm for automatic detection of pulmonary nodules. The algorithm is designed to detect nodules with diameters of at least 5 mm. A total of 153 nodules were detected with at least one modality (radiologists in consensus, CAD, 85 nodules with diameter <5 mm, 68 with diameter ≥5 mm). The results of automatic nodule detection were compared to nodules detected with any modality as gold standard. Computer-aided diagnosis correctly identified 26 of 59 (38%) nodules with diameters ≥5 mm detected by visual assessment by the radiologists; of these, CAD detected 44% (24 of 54) nodules without pleural contact. In addition, 12 nodules ≥5 mm were detected which were not mentioned in the radiologist's report but represented real nodules. Sensitivity for detection of nodules ≥5 mm was 85% (58 of 68) for radiologists and 38% (26 of 68) for CAD. There were 5.8±3.6 false-positive results of CAD per CT study. Computer-aided diagnosis improves detection of pulmonary nodules at spiral CT and is a valuable second opinion in a clinical setting for lung cancer screening despite of its still limited sensitivity. (orig.)

  19. Spontaneous Regression of Pulmonary Nodules Presenting as Epstein-Barr Virus-related Atypical Infectious Mononucleosis.

    Science.gov (United States)

    Shinozuka, Jun; Awaguni, Hitoshi; Tanaka, Shin-Ichiro; Makino, Shigeru; Maruyama, Rikken; Inaba, Tohru; Imashuku, Shinsaku

    2016-07-01

    Pulmonary nodules associated with Epstein-Barr virus (EBV)-related atypical infectious mononucleosis have rarely been described. A 12-year-old Japanese boy, upon admission, revealed multiple small round nodules (a total of 7 nodules in 4 to 8 mm size) in the lungs on computed tomography. The hemorrhagic pharyngeal tonsils with hot signals on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography were biopsied revealing the presence of EBV-encoded small nuclear RNA (EBER)-positive cells; however, no lymphoma was noted. The patient was diagnosed as having atypical EBV-infectious mononucleosis associated with primary EBV infection. Pulmonary nodules markedly reduced in numbers and sizes spontaneously over a 2-year period. Differential diagnosis of pulmonary nodules in childhood should include atypical EBV infection.

  20. Automatic detection of spiculation of pulmonary nodules in computed tomography images

    DEFF Research Database (Denmark)

    Ciompi, F; Jacobs, C; Scholten, E.T.

    2015-01-01

    to classify spiculated nodules via supervised learning. We tested our approach on a set of nodules from the Danish Lung Cancer Screening Trial (DLCST) dataset. Our results show that the proposed method outperforms other 3-D descriptors of morphology in the automatic assessment of spiculation. © (2015......-up procedure. For this reason, lung cancer screening scenario would benefit from the presence of a fully automatic system for the assessment of spiculation. The presented framework relies on the fact that spiculated nodules mainly differ from non-spiculated ones in their morphology. In order to discriminate....... A library of spectra is created by clustering data via unsupervised learning. The centroids of the clusters are used to label back each spectrum in the sampling pattern. A compact descriptor encoding the nodule morphology is obtained as the histogram of labels along all the spherical surfaces and used...

  1. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 report

    DEFF Research Database (Denmark)

    Field, John K; Smith, Robert A; Aberle, Denise R

    2011-01-01

    national screening programs; (iii) develop guidelines for the clinical work-up of "indeterminate nodules" resulting from CT screening programmers; (iv) guidelines for pathology reporting of nodules from lung cancer CT screening programs; (v) recommendations for surgical and therapeutic interventions...... of suspicious nodules identified through lung cancer CT screening programs; and (vi) integration of smoking cessation practices into future national lung cancer CT screening programs....

  2. Usefulness of CT-guided automatic needle biopsy of solitary pulmonary nodule smaller than 15 mm

    International Nuclear Information System (INIS)

    Jin, Gong Yong; Lim, Yeong Su

    2004-01-01

    To evaluate the usefulness of the CT-guided percutaneous lung biopsy for the solitary pulmonary nodules smaller than 15 mm in diameter. Between April 2002 and May 2003, we evaluated twenty-five patients (11 men, 14 women, mean ages: 52.5 years) who had solitary pulmonary nodules, which we could not discriminate as being benign or malignant on the CT findings. All the subjects had CT-guided percutaenous cutting needle biopsy (PCNB) performed on them at our institution. A definitive diagnosis of benignity or malignancy was established to retrospectively analyze the patient's records. We evaluated the accuracy, sensitivity, specificity and complications of PCNB for the definitive diagnosis of benignity or malignancy. The sensitivity and specificity of PCNB were determined using the Chi-square test, and the correlations with pneumothorax and emphysema after biopsy were analyzed using Spearman's rank correlation coefficient. In two nodules of the twenty-five nodules, no definitive diagnosis could be established. Of the remaining twenty-three nodules, 7 (30.4%) were malignant and 16 (69.6%) were benign. Twenty (87%) of the twenty-three definitively diagnosed nodules were correctly diagnosed with PCNB. Of the twenty nodules, 6 (30%) were malignant and 14 (70%) were benign. The sensitivity and specificity of the malignant nodules were 85.7% (6/7) and 100% (16/16), respectively. The sensitivity and specificity of the benign nodules were 87.5% (14/16) and 85.7% (6/7), respectively. Post-biopsy complication occurred in nine patients (36%): Hemoptysis (n=4, 16%) and pneumothorax (n=5, 20%). However, there was not a statistical significance between pneumothorax and emphysema after biopsy (r=0.3, p=0.15). When CT-guided percutaneous lung biopsy of the solitary pulmonary nodules smaller than 15 mm in diameter was performed without an on-site cytopathologist, we know that PCNB can yield high diagnostic accuracy and very few complications

  3. Volumetric measurements of pulmonary nodules at multi-row detector CT: in vivo reproducibility

    International Nuclear Information System (INIS)

    Wormanns, Dag; Marheine, Anke; Beyer, Florian; Heindel, Walter; Diederich, Stefan; Kohl, Gerhard; Klotz, Ernst

    2004-01-01

    The aim of this study was to assess the in vivo measurement precision of a software tool for volumetric analysis of pulmonary nodules from two consecutive low-dose multi-row detector CT scans. A total of 151 pulmonary nodules (diameter 2.2-20.5 mm, mean diameter 7.4±4.5 mm) in ten subjects with pulmonary metastases were examined with low-dose four-detector-row CT (120 kVp, 20 mAs (effective), collimation 4 x 1 mm, normalized pitch 1.75, slice thickness 1.25 mm, reconstruction increment 0.8 mm; Somatom VolumeZoom, Siemens). Two consecutive low-dose scans covering the whole lung were performed within 10 min. Nodule volume was determined for all pulmonary nodules visually detected in both scans using the volumetry tool included in the Siemens LungCare software. The 95% limits of agreement between nodule volume measurements on different scans were calculated using the Bland and Altman method for assessing measurement agreement. Intra- and interobserver agreement of volume measurement were determined using repetitive measurements of 50 randomly selected nodules at the same scan by the same and different observers. Taking into account all 151 nodules, 95% limits of agreement were -20.4 to 21.9% (standard error 1.5%); they were -19.3 to 20.4% (standard error 1.7%) for 105 nodules <10 mm. Limits of agreement were -3.9 to 5.7% for intraobserver and -5.5 to 6.6% for interobserver agreement. Precision of in vivo volumetric analysis of nodules with an automatic volumetry software tool was sufficiently high to allow for detection of clinically relevant growth in small pulmonary nodules. (orig.)

  4. Noninvasive Characterization of Indeterminate Pulmonary Nodules Detected on Chest High-Resolution Computed Tomography

    Science.gov (United States)

    2016-10-01

    Current Status ANALYZE Nodule Segmentation CANARY -PLUS ANALYZE AVW Surface Extraction In-house monolithic software ADMesh Surface Repair MATLAB...a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2016 2. REPORT TYPE Annual 3...we are currently developing a multivariate radiologic prediction model (radiologic model) using a population of benign and malignant lung nodules

  5. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules.......In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  6. Laser-induced cavitation based micropump

    NARCIS (Netherlands)

    Dijkink, R.J.; Ohl, C.D.

    2008-01-01

    Lab-on-a-chip devices are in strong demand as versatile and robust pumping techniques. Here, we present a cavitation based technique, which is able to pump a volume of 4000 m3 within 75 s against an estimated pressure head of 3 bar. The single cavitation event is created by focusing a laser pulse in

  7. Travelling Bubble Cavitation and Resulting Noise.

    Science.gov (United States)

    1981-03-02

    pp. 22-26, 1968. 16. Il’ichev, V. I. "Statistical Model of the Onset of Hydrodynamic Cavitation Noise," Sixth All-Union Acoustic Conference...Collected Papers, Moscow, 1968. 17. Lyamshev, L. M. "On the Theory of Hydrodynamic Cavitation Noise," Soviet Physics-Acoustics, Vol. 15, pp. 494-498, 1970. 18

  8. The incidental pulmonary nodule in a child. Part 2: Commentary and suggestions for clinical management, risk communication and prevention

    International Nuclear Information System (INIS)

    Westra, Sjirk J.; Thacker, Paul G.; Podberesky, Daniel J.; Lee, Edward Y.; Iyer, Ramesh S.; Hegde, Shilpa V.; Guillerman, R.P.; Mahani, Maryam Ghadimi

    2015-01-01

    The incidental detection of small lung nodules in children is a vexing consequence of an increased reliance on CT. We present an algorithm for the management of lung nodules detected on CT in children, based on the presence or absence of symptoms, the presence or absence of elements in the clinical history that might explain these nodules, and the imaging characteristics of the nodules (such as attenuation measurements within the nodule). We provide suggestions on how to perform a thoughtfully directed and focused search for clinically occult extrathoracic disease processes (including malignant disease) that may present as an incidentally detected lung nodule on CT. This algorithm emphasizes that because of the lack of definitive information on the natural history of small solid nodules that are truly detected incidentally, their clinical management is highly dependent on the caregivers' individual risk tolerance. In addition, we present strategies to reduce the prevalence of these incidental findings, by preventing unnecessary chest CT scans or inadvertent inclusion of portions of the lungs in scans of adjacent body parts. Application of these guidelines provides pediatric radiologists with an important opportunity to practice patient-centered and evidence-based medicine. (orig.)

  9. Pulmonary nodules in workers exposed to urban stressor

    International Nuclear Information System (INIS)

    Sancini, A.; Fioravanti, M.; Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P.; Tomei, G.; Tomei, F.

    2010-01-01

    By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM 10 , NO 2 and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung

  10. Pulmonary nodules in workers exposed to urban stressor

    Energy Technology Data Exchange (ETDEWEB)

    Sancini, A. [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Fioravanti, M. [University of Rome ' Sapienza' , Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P. [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Tomei, G. [University of Rome ' Sapienza' , Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Tomei, F., E-mail: francesco.tomei@uniroma1.it [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy)

    2010-07-15

    By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM{sub 10}, NO{sub 2} and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid

  11. [Nodulation competitiveness of nodule bacteria: Genetic control and adaptive significance].

    Science.gov (United States)

    Onishchuk, O P; Vorobyov, N I; Provorov, N A

    2017-01-01

    The most recent data on the system of cmp (competitiveness) genes that determine the nodulation competitiveness of rhizobial strains, i.e., the ability to compete for nodule formation in leguminous plants, is analyzed. Three genetic approaches for the construction of economically valuable strains of rhizobia are proposed: the amplification of positive regulators of competitiveness, the inactivation of the negative regulators of this trait, and the introduction of efficient competitiveness factors into strains capable of active nitrogen fixation.

  12. Cavitation occurrence around ultrasonic dental scalers.

    Science.gov (United States)

    Felver, Bernhard; King, David C; Lea, Simon C; Price, Gareth J; Damien Walmsley, A

    2009-06-01

    Ultrasonic scalers are used in dentistry to remove calculus and other contaminants from teeth. One mechanism which may assist in the cleaning is cavitation generated in cooling water around the scaler. The vibratory motion of three designs of scaler tip in a water bath has been characterised by laser vibrometry, and compared with the spatial distribution of cavitation around the scaler tips observed using sonochemiluminescence from a luminol solution. The type of cavitation was confirmed by acoustic emission analysed by a 'Cavimeter' supplied by NPL. A node/antinode vibration pattern was observed, with the maximum displacement of each type of tip occurring at the free end. High levels of cavitation activity occurred in areas surrounding the vibration antinodes, although minimal levels were observed at the free end of the tip. There was also good correlation between vibration amplitude and sonochemiluminescence at other points along the scaler tip. 'Cavimeter' analysis correlated well with luminol observations, suggesting the presence of primarily transient cavitation.

  13. Reflections on cavitation nuclei in water

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2007-01-01

    to explaining why the tensile strength of water varies so dramatically between the experiments reported. A model for calculation of the critical pressure of skin-covered free gas bubbles as well as that of interfacial gaseous nuclei covered by a skin is presented. This model is able to bridge the apparently......The origin of cavitation bubbles, cavitation nuclei, has been a subject of debate since the early years of cavitation research. This paper presents an analysis of a representative selection of experimental investigations of cavitation inception and the tensile strength of water. At atmospheric...... pressure, the possibility of stabilization of free gas bubbles by a skin has been documented, but only within a range of bubble sizes that makes them responsible for tensile strengths up to about 1.5 bar, and values reaching almost 300 bar have been measured. However, cavitation nuclei can also be harbored...

  14. Comparison of Different Mathematical Models of Cavitation

    Directory of Open Access Journals (Sweden)

    Dorota HOMA

    2014-12-01

    Full Text Available Cavitation occurs during the flow when local pressure drops to the saturation pressure according to the temperature of the flow. It includes both evaporation and condensation of the vapor bubbles, which occur alternately with high frequency. Cavitation can be very dangerous, especially for pumps, because it leads to break of flow continuity, noise, vibration, erosion of blades and change in pump’s characteristics. Therefore it is very important for pump designers and users to avoid working in cavitation conditions. Simulation of flow can be very useful in that and can indicate if there is risk of cavitating flow occurrence. As this is a multiphase flow and quite complicated phenomena, there are a few mathematical models describing it. The aim of this paper is to make a short review of them and describe their approach to model cavitation. It is desirable to know differences between them to model this phenomenon properly.

  15. The acoustic detection of cavitation in pumps

    International Nuclear Information System (INIS)

    Macleod, I.D.; Gray, B.S.; Taylor, C.G.

    1978-01-01

    A programme was initiated to develop a reliable technique for detecting the onset of acoustic noise from cavitation in a pump and to relate this to cavitation inception data, since significant noise from collapse of vapour bubbles arising from such cavitation would reduce the sensitivity of a noise detection system for boiling of sodium in fast breeder reactors. Factors affecting the detection of cavitation are discussed. The instrumentation and techniques of frequency analysis and pulse detection are described. Two examples are then given of the application of acoustic detection techniques under controlled conditions. It is concluded that acoustic detection can be a reliable method for detecting inception of cavitation in a pump and the required conditions are stated. (U.K.)

  16. Diagnostic value of contrast-enhanced dynamic CT in predicting the malignancy of solitary pulmonary nodules

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Song, Koun Sik; Lee, Eun Hye; Kim, Ji Hoon; Lee, Jin Seong; Lim, Tae Hwan

    1997-01-01

    To determine whether the maximal enhancement time in dynamic CT is different between benign and malignant solitary pulmonary nodules (SPN)s, and to evaluate the value of densitometry on dynamic CT in predicting the malignancy of SPN. Fifty-six patients with SPN of less than 4cm in diameter as seen on chest radiograph and SPN without benign pattern of calcification or fat, as seen on pre-enhance-ment spiral CT scans were included in this study. SPN with small cavitation sufficient to measure CT density, were also included. Thirty-four SPNs were diagnosed pathologically or radiologically as 20 malignant nodules and 14 benign nodules. Dynamic CT was performed by two techniques after injection of 50ml of nonionic contrast media at the rate of 2ml/sec. In 28 patients, incremental dynamic CT was performed before and of 15 seconds, 1 minute, 2 minutes, 3 minutes, and 4 minutes after injection of contrast media during shallow respiration. In 28 patients, double spiral CT was performed 2 minutes and 3 minutes after injection of contrast media during single breath hold. CT readings were taken at the central portion of SPNs, with a circular region of interest. The degree and time of maximal enhancement were recorded. In dynamic CT the maximal enhancement time of SPNs was not significantly different between malignant (2.73±1.27 minute) and benign nodules (2.56±1.24 minute). The enhancement of malignant nodules was significantly greater (21.42±12.17 HU) than of benign nodules (5.15±5.25 HU) (p<.0001). In dynamic CT of SPNs, there is no difference in maximal enhancement time between benign and malignant nodules;enhancement of the latter is significantly greater than that of the former. Maximal enhancement greater than 15 HU can be a good predictor of malignancy of SPNs

  17. Detection of cavitation in hydraulic turbines

    Science.gov (United States)

    Escaler, Xavier; Egusquiza, Eduard; Farhat, Mohamed; Avellan, François; Coussirat, Miguel

    2006-05-01

    An experimental investigation has been carried out in order to evaluate the detection of cavitation in actual hydraulic turbines. The methodology is based on the analysis of structural vibrations, acoustic emissions and hydrodynamic pressures measured in the machine. The proposed techniques have been checked in real prototypes suffering from different types of cavitation. In particular, one Kaplan, two Francis and one Pump-Turbine have been investigated in the field. Additionally, one Francis located in a laboratory has also been tested. First, a brief description of the general features of cavitation phenomenon is given as well as of the main types of cavitation occurring in hydraulic turbines. The work presented here is focused on the most important ones which are the leading edge cavitation due to its erosive power, the bubble cavitation because it affects the machine performance and the draft tube swirl that limits the operation stability. Cavitation detection is based on the previous understanding of the cavity dynamics and its location inside the machine. This knowledge has been gained from flow visualisations and measurements in laboratory devices such as a high-speed cavitation tunnel and a reduced scale turbine test rig. The main techniques are the study of the high frequency spectral content of the signals and of their amplitude demodulation for a given frequency band. Moreover, low frequency spectral content can also be used in certain cases. The results obtained for the various types of cavitation found in the selected machines are presented and discussed in detail in the paper. Conclusions are drawn about the best sensor, measuring location, signal processing and analysis for each type of cavitation, which serve to validate and to improve the detection techniques.

  18. Hyperfunctioning thyroid nodules in children.

    Science.gov (United States)

    Abe, K; Konno, M; Sato, T; Matsuura, N

    1980-10-01

    We studied two cases of hyperfunctioning thyroid nodules in children. A 9-year-old girl and an 11-year-old girl had thyroid masses in otherwise nonpalpable thyroid glands. Scintiscan showed hyperfunctioning thyroid nodules. The former patient had elevated values for T4 and T3, and plasma thyrotropin (TSH) level failed to respond to stimulation with thyrotropin releasing hormone (TRH), whereas the latter patient had normal values for T4, and T3 and plasma TSH response to TRH was normal. After the surgical removal of nodules, scintiscan exhibited radioactivity in the contralateral lobe of the thyroid gland in the former and in the ectopic thyroid tissue in the latter. Results of microscopic examinations of thyroid nodules were consistent with adenomatous goiter.

  19. Enterobacter Asburiae Pneumonia with Cavitation

    International Nuclear Information System (INIS)

    Cha, Seung Woo; Heo, Jeong Nam; Park, Choong Ki; Choi, Yo Won; Jeon, Seok Chol

    2013-01-01

    Enterobacter species have increasingly been identified as pathogens over the past several decades. These bacterial species have become more important because most are resistant to cephalothin and cefoxitin, and can produce extended-spectrum β-lactamase. Enterobacter asburiae (E. asburiae) is a gram-negative rod of the family Enterobacteriaceae, named in 1986. Since then, there has been only one clinical report of E. asburiae pneumonia. We report a case of E. asburiae pneumonia with cavitation and compare it with the previous case.

  20. Enterobacter Asburiae Pneumonia with Cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seung Woo; Heo, Jeong Nam; Park, Choong Ki [Dept. of Radiology, Hanyang University College of Medicine, Guri Hospital, Guri (Korea, Republic of); Choi, Yo Won; Jeon, Seok Chol [Dept. of Radiology, Hanyang University College of Medicine, Seoul Hospital, Seoul (Korea, Republic of)

    2013-03-15

    Enterobacter species have increasingly been identified as pathogens over the past several decades. These bacterial species have become more important because most are resistant to cephalothin and cefoxitin, and can produce extended-spectrum {beta}-lactamase. Enterobacter asburiae (E. asburiae) is a gram-negative rod of the family Enterobacteriaceae, named in 1986. Since then, there has been only one clinical report of E. asburiae pneumonia. We report a case of E. asburiae pneumonia with cavitation and compare it with the previous case.

  1. Superhigh Temperatures and Acoustic Cavitation

    CERN Document Server

    Belyaev, V B; Miller, M B; Sermyagin, A V; Topolnikov, A S

    2003-01-01

    The experimental results on thermonuclear synthesis under acoustic cavitation have been analyzed with the account of the latest data and their discussion. The analysis testifies that this avenue of research is a very promising one. The numerical calculations of the D(d, n)^{3}He reaction rate in the deuterated acetone (C_{3}D_{6}O) under the influence of ultrasound depending on T environment temperature within the range T=249-295 K have been carried out within the framework of hydrodynamic model. The results show that it is possible to improve substantially the effect/background relationship in experiments by decreasing the fluid temperature twenty-thirty degrees below zero.

  2. Super-Cavitating Flow Around Two-Dimensional Conical, Spherical, Disc and Stepped Disc Cavitators

    Science.gov (United States)

    Sooraj, S.; Chandrasekharan, Vaishakh; Robson, Rony S.; Bhanu Prakash, S.

    2017-08-01

    A super-cavitating object is a high speed submerged object that is designed to initiate a cavitation bubble at the nose which extends past the aft end of the object, substantially reducing the skin friction drag that would be present if the sides of the object were in contact with the liquid in which the object is submerged. By reducing the drag force the thermal energy consumption to move faster can also be minimised. The super-cavitation behavioural changes with respect to Cavitators of various geometries have been studied by varying the inlet velocity. Two-dimensional computational fluid dynamics analysis has been carried out by applying k-ε turbulence model. The variation of drag coefficient, cavity length with respect to cavitation number and inlet velocity are analyzed. Results showed conical Cavitator with wedge angle of 30° has lesser drag coefficient and cavity length when compared to conical Cavitators with wedge angles 45° and 60°, spherical, disc and stepped disc Cavitators. Conical cavitator 60° and disc cavitator have the maximum cavity length but with higher drag coefficient. Also there is significant variation of supercavitation effect observed between inlet velocities of 32 m/s to 40 m/s.

  3. Nodule detection in digital chest radiography: Introduction to the radius chest trial

    International Nuclear Information System (INIS)

    Baath, M.; Haakansson, M.; Boerjesson, S.; Kheddache, S.; Grahn, A.; Ruschin, M.; Tingberg, A.; Mattsson, S.; Maansson, L. G.

    2005-01-01

    Most digital radiographic systems of today have wide latitude and are hence able to provide images with a small constraint on dose level. This opens up for an unprejudiced dose optimisation. However, in order to succeed in the optimisation task, good knowledge of the imaging and detection processes is needed. As a part of the European-wide research project 'unification of physical and clinical requirements for medical X-ray imaging - governed by the Radiological Imaging Unification Strategies (RADIUS) Group - a major image quality trial was conducted by members of the group. The RADIUS chest trial was focused on the detection of lung nodules in digital chest radiography with the aims of determining to what extent (1) the detection of a nodule is dependent on its location, (2) the system noise disturbs the detection of lung nodules, (3) the anatomical noise disturbs the detection of lung nodules and (4) the image background and anatomical background act as pure noise for the detection of lung nodules. The purpose of the present paper is to give an introduction to the trial and describe the framework and set-up of the investigation. (authors)

  4. Role of Computer Aided Diagnosis (CAD in the detection of pulmonary nodules on 64 row multi detector computed tomography

    Directory of Open Access Journals (Sweden)

    K Prakashini

    2016-01-01

    Full Text Available Aims and Objectives: To determine the overall performance of an existing CAD algorithm with thin-section computed tomography (CT in the detection of pulmonary nodules and to evaluate detection sensitivity at a varying range of nodule density, size, and location. Materials and Methods: A cross-sectional prospective study was conducted on 20 patients with 322 suspected nodules who underwent diagnostic chest imaging using 64-row multi-detector CT. The examinations were evaluated on reconstructed images of 1.4 mm thickness and 0.7 mm interval. Detection of pulmonary nodules, initially by a radiologist of 2 years experience (RAD and later by CAD lung nodule software was assessed. Then, CAD nodule candidates were accepted or rejected accordingly. Detected nodules were classified based on their size, density, and location. The performance of the RAD and CAD system was compared with the gold standard that is true nodules confirmed by consensus of senior RAD and CAD together. The overall sensitivity and false-positive (FP rate of CAD software was calculated. Observations and Results: Of the 322 suspected nodules, 221 were classified as true nodules on the consensus of senior RAD and CAD together. Of the true nodules, the RAD detected 206 (93.2% and 202 (91.4% by the CAD. CAD and RAD together picked up more number of nodules than either CAD or RAD alone. Overall sensitivity for nodule detection with the CAD program was 91.4%, and FP detection per patient was 5.5%. The CAD showed comparatively higher sensitivity for nodules of size 4-10 mm (93.4% and nodules in hilar (100% and central (96.5% location when compared to RAD′s performance. Conclusion: CAD performance was high in detecting pulmonary nodules including the small size and low-density nodules. CAD even with relatively high FP rate, assists and improves RAD′s performance as a second reader, especially for nodules located in the central and hilar region and for small nodules by saving RADs time.

  5. Cavitation Inception Scale Effects. 1. Nuclei Distributions in Natural Waters. 2. Cavitation Inception in a Turbulent Shear Flow.

    Science.gov (United States)

    1987-05-01

    cavitation is pressure-controlled. The term hydrodynamic cavitation is some- times used to stress the dominant role of dynamic pressure in the cavitation...Diffraction Pattern of Opaque and Transparent Objects with Coherent Back- ground," Optica Acta, 11, 183-193. Peterson, F.B. (1972), " Hydrodynamic Cavitation and

  6. Radiological aspects of bacterial lung abscess

    International Nuclear Information System (INIS)

    Groskin, S.A.; Panicek, D.; Ewing, D.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    Clinical, radiological, and pathological data derived from an analysis of over 70 cases of bacterial lung abscess are presented. Etiologic agents and risk factors are presented. Key radiographic findings are discussed, and those that are most useful in differentiating bacterial lung abscess from cavitated carcinoma, infected cyst, and emphysema are emphasized. Radiographic aspects of the complications of bacterial lung abscess are illustrated, and radiological approaches to their therapy are discussed

  7. An Anticipatory Model of Cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Dress, W.B., Jr.; Hylton, J.O.; Kercel, S.W.

    1999-04-05

    The Anticipatory System (AS) formalism developed by Robert Rosen provides some insight into the problem of embedding intelligent behavior in machines. AS emulates the anticipatory behavior of biological systems. AS bases its behavior on its expectations about the near future and those expectations are modified as the system gains experience. The expectation is based on an internal model that is drawn from an appeal to physical reality. To be adaptive, the model must be able to update itself. To be practical, the model must run faster than real-time. The need for a physical model and the requirement that the model execute at extreme speeds, has held back the application of AS to practical problems. Two recent advances make it possible to consider the use of AS for practical intelligent sensors. First, advances in transducer technology make it possible to obtain previously unavailable data from which a model can be derived. For example, acoustic emissions (AE) can be fed into a Bayesian system identifier that enables the separation of a weak characterizing signal, such as the signature of pump cavitation precursors, from a strong masking signal, such as a pump vibration feature. The second advance is the development of extremely fast, but inexpensive, digital signal processing hardware on which it is possible to run an adaptive Bayesian-derived model faster than real-time. This paper reports the investigation of an AS using a model of cavitation based on hydrodynamic principles and Bayesian analysis of data from high-performance AE sensors.

  8. Released air during vapor and air cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Jablonská, Jana, E-mail: jana.jablonska@vsb.cz; Kozubková, Milada, E-mail: milada.kozubkova@vsb.cz [VŠB-Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Hydromechanics and Hydraulic Equipment, 17. listopadu 15, 708 33 Ostrava-Poruba (Czech Republic)

    2016-06-30

    Cavitation today is a very important problem that is solved by means of experimental and mathematical methods. The article deals with the generation of cavitation in convergent divergent nozzle of rectangular cross section. Measurement of pressure, flow rate, temperature, amount of dissolved air in the liquid and visualization of cavitation area using high-speed camera was performed for different flow rates. The measurement results were generalized by dimensionless analysis, which allows easy detection of cavitation in the nozzle. For numerical simulation the multiphase mathematical model of cavitation consisting of water and vapor was created. During verification the disagreement with the measurements for higher flow rates was proved, therefore the model was extended to multiphase mathematical model (water, vapor and air), due to release of dissolved air. For the mathematical modeling the multiphase turbulence RNG k-ε model for low Reynolds number flow with vapor and air cavitation was used. Subsequently the sizes of the cavitation area were verified. In article the inlet pressure and loss coefficient depending on the amount of air added to the mathematical model are evaluated. On the basis of the approach it may be create a methodology to estimate the amount of released air added at the inlet to the modeled area.

  9. Periodic cavitation shedding in a cylindrical orifice

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, C.; Barber, T.; Milton, B.; Rosengarten, G. [University of New South Wales, School of Mechanical and Manufacturing Engineering, Sydney (Australia)

    2011-11-15

    Cavitation structures in a large-scale (D = 8.25 mm), plain orifice style nozzle within a unique experimental rig are investigated using high-speed visualisation and digital image processing techniques. Refractive index matching with an acrylic nozzle is achieved using aqueous sodium iodide for the test fluid. Cavitation collapse length, unsteady shedding frequency and spray angles are measured for cavitation conditions from incipient to supercavitation for a range of Reynolds numbers, for a fixed L/D ratio of 4.85. Periodic cavitation shedding was shown to occur with frequencies between 500 and 2,000 Hz for conditions in which cavitation occupied less than 30% of the nozzle length. A discontinuity in collapse length was shown to occur once the cavitation exceeded this length, coinciding with a loss of periodic shedding. A mechanism for this behaviour is discussed. Peak spray angles of approximately {theta} {approx} 14 were recorded for supercavitation conditions indicating the positive influence of cavitation bubble collapse on the jet atomisation process. (orig.)

  10. Comparative analysis between spiral CT and pathology of pulmonary nodules

    International Nuclear Information System (INIS)

    Wang Kaifu; Zhang Zhanqing

    2007-01-01

    Objective: To explore the value of spiral CT in the diagnosis of atypical pulmonary nodules. Methods: CT, clinic and histopathologic data of 72 patients with atypical pulmonary nodules confirmed by surgical resection in 41 cases and/or biopsy in 31 cases were retrospectively analyzed. Results: CT scans demonstrated slight lobulation in 34 cases, irregular margin in 50 cases, long speculate in 10 cases, air-bronchogram in 2 case, vacuole in 2 case. 38 pulmonary cancer, 22 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were diagnosed with spiral CT. However, 30 pulmonary cancer, 30 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were confirmed by histopathology. The overall accurate diagnostic rate of pulmonary cancer was 66.7% (20/30), pulmonary tuberculosis was 60%(18/30), pulmonary inflammatory pseudotumors was 16.7%(2/12). 40 cases were diagnosed correctly and 32 cases were misdiagnosed with CT in 72 cases of atypical pulmonary nodules. The misdiagnostic rate of CT was 44.4%. 10 cases of lung cancer were misdiagnosed, including 4 cases of tuberculosis (long speculate or irregular margin) and 6 cases of inflammatory pseudotumors (irregular margin or long speculate or air-bronchogram). 12 cases of tuberculosis were misdiagnosed, including 8 cases lung cancer (slight lobulation) and 4 cases of inflammatory pseudotumors (slight lobulation). 10 cases inflammatory pseudotumor were misdiagnosed as lung cancer (slight lobulation). Conclusion: Spiral CT was very useful in the localization and morphological describing, but difficult in qualitative diagnosing of atypical pulmonary nodules, exactly diagnosis was relied on surgery and biopsy. (authors)

  11. Experimental and numerical studies on super-cavitating flow of axisymmetric cavitators

    Directory of Open Access Journals (Sweden)

    Byoung-Kwon Ahn

    2010-03-01

    Full Text Available Recently underwater systems moving at high speed such as a super-cavitating torpedo have been studied for their practical advantage of the dramatic drag reduction. In this study we are focusing our attention on super-cavitating flows around axisymmetric cavitators. A numerical method based on inviscid flow is developed and the results for several shapes of the cavitator are presented. First using a potential based boundary element method, we find the shape of the cavitator yielding a sufficiently large enough cavity to surround the body. Second, numerical predictions of supercavity are validated by comparing with experimental observations carried out in a high speed cavitation tunnel at Chungnam National University (CNU CT.

  12. Degradation of chlorocarbons driven by hydrodynamic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.L.; Ondruschka, B.; Braeutigam, P. [Institut fuer Technische Chemie und Umweltchemie, Friedrich-Schiller-Universitaet Jena, Jena (Germany)

    2007-05-15

    To provide an efficient lab-scale device for the investigation of the degradation of organic pollutants driven by hydrodynamic cavitation, the degradation kinetics of chloroform and carbon tetrachloride and the increase of conductivity in aqueous solutions were measured. These are values which were not previously available. Under hydrodynamic cavitation conditions, the degradation kinetics for chlorocarbons was found to be pseudo first-order. Meanwhile, C-H and C-Cl bonds are broken, and Cl{sub 2}, Cl{sup .}, Cl{sup -} and other ions released can increase the conductivity and enhance the oxidation of KI in aqueous solutions. The upstream pressures of the orifice plate, the cavitation number, and the solution temperature have substantial effects on the degradation kinetics. A decreased cavitation number can result in more cavitation events and enhances the degradation of chlorocarbons and/or the oxidation of KI. A decrease in temperature is generally favorable to the cavitation chemistry. Organic products from the degradation of carbon tetrachloride and chloroform have demonstrated the formation and recombination of free radicals, e.g., CCl{sub 4}, C{sub 2}Cl{sub 4}, and C{sub 2}Cl{sub 6} are produced from the degradation of CHCl{sub 3}. CHCl{sub 3} and C{sub 2}Cl{sub 6} are produced from the degradation of CCl{sub 4}. Both the chemical mechanism and the reaction kinetics of the degradation of chlorocarbons induced by hydrodynamic cavitation are consistent with those obtained from the acoustic cavitation. Therefore, the technology of hydrodynamic cavitation should be a good candidate for the removal of organic pollutants from water. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  13. Solitary pulmonary nodule: radiologic features and diagnostic approach; Nodulo pulmonar solitario: caracteristicas radiologicas y abordaje diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Cambronero, Luis Enrique

    2012-07-01

    A literature review is conducted on the solitary pulmonary nodule, to determine the diagnostic methods and specific characteristics. The diagnostic methods used have been: chest radiography, computed tomography, positron emission tomography and magnetic resonance imaging. The radiological features are defined: location, size, definition of contours or edges (margins), densitometric and attenuation characteristics, cavitation, air bronchogram, growth, doubling time, satellite nodules, nutrient vessels [Spanish] Una revision bibliografica es realizada sobre el nodulo pulmonar solitario, para determinar los metodos de diagnostico y caracteristicas especificas. Los metodos de diagnostico utilizados han sido: la radiografia de torax, tomografia computarizada, tomografia por emision de positrones y resonancia magnetica. Las caracteristicas radiologicas son definidas: localizacion, tamano, definicion de los bordes o contornos (margenes), caracteristicas densitometricas y de atenuacion, cavitacion, broncograma aereo, crecimiento, tiempo de duplicacion, nodulos satelite, vasos nutrientes.

  14. RANS computations of tip vortex cavitation

    Science.gov (United States)

    Decaix, Jean; Balarac, Guillaume; Dreyer, Matthieu; Farhat, Mohamed; Münch, Cécile

    2015-12-01

    The present study is related to the development of the tip vortex cavitation in Kaplan turbines. The investigation is carried out on a simplified test case consisting of a NACA0009 blade with a gap between the blade tip and the side wall. Computations with and without cavitation are performed using a R ANS modelling and a transport equation for the liquid volume fraction. Compared with experimental data, the R ANS computations turn out to be able to capture accurately the development of the tip vortex. The simulations have also highlighted the influence of cavitation on the tip vortex trajectory.

  15. Control of hydrodynamic cavitation using ultrasonic

    Science.gov (United States)

    Chatterjee, Dhiman; Arakeri, Vijay H.

    2003-11-01

    Hydrodynamic cavitation is known to have many harmful effects like surface damage and generation of noise. We investigated the use of ultrasonics to control traveling bubble cavitation. Ultrasonic pressure field, produced by a piezoelectric crystal, was applied to modify the nuclei size distribution. Effects of continuous-wave (CW) and pulsed excitations were studied. At low dissolved gas content the CW-mode performed better than the pulsed one, whereas for high gas content the pulsed one was more effective. The dominant mechanisms were Bjerknes force and rectified diffusion in these two cases. Simultaneous excitation by two crystals in CW and pulsed modes was seen to control cavitation better.

  16. Overview of Rotating Cavitation and Cavitation Surge in the Fastrac Engine LOX Turbopump

    Science.gov (United States)

    Zoladz, Thomas; Turner, Jim (Technical Monitor)

    2001-01-01

    Observations regarding rotating cavitation and cavitation surge experienced during the development of the Fastrac 60 Klbf engine turbopump are discussed. Detailed observations from the analysis of both water flow and liquid oxygen test data are offered. Scaling and general comparison of rotating cavitation between water flow and liquid oxygen testing are discussed. Complex data features linking the localized rotating cavitation mechanism of the inducer to system surge components are described in detail. Finally a description of a simple lumped-parameter hydraulic system model developed to better understand observed data is given.

  17. Cavitation propagation in water under tension

    Science.gov (United States)

    Noblin, Xavier; Yip Cheung Sang, Yann; Pellegrin, Mathieu; Materials and Complex Fluids Team

    2012-11-01

    Cavitation appears when pressure decreases below vapor pressure, generating vapor bubbles. It can be obtain in dynamical ways (acoustic, hydraulic) but also in quasi-static conditions. This later case is often observed in nature, in trees, or during the ejection of ferns spores. We study the cavitation bubbles nucleation dynamics and its propagation in a confined microfabricated media. This later is an ordered array of microcavities made in hydrogel filled with water. When the system is put into dry air, it dehydrates, water leaves the cavities and tension (negative pressure) builds in the cavities. This can be sustained up to a critical pressure (of order -20 MPa), then cavitation bubbles appear. We follow the dynamics using ultra high speed imaging. Events with several bubbles cavitating in a few microseconds could be observed along neighboring cells, showing a propagation phenomenon that we discuss. ANR CAVISOFT 2010-JCJC-0407 01.

  18. Cavitation in pumps, pipes and valves

    International Nuclear Information System (INIS)

    Young, Ronald.

    1990-01-01

    The phenomenon of cavitation, often perceived as merely a nuisance, may have far more serious implications. These are discussed here. They include noise, loss of performance and damage to the constituent parts. (author)

  19. Cavitation for improved sludge conversion into biogas

    Science.gov (United States)

    Stoop, A. H.; Bakker, T. W.; Kramer, H. J. M.

    2015-12-01

    In several studies the beneficial influence of pre-treatment of waste activated sludge with cavitation on the biogas production was demonstrated. It is however, still not fully certain whether this effect should be mainly contributed to an increase in conversion rate of organics into biogas by anaerobic bacteria, and how much cavitation increases the total biogas yield. An increase in yield is only the case if cavitation can further disrupt otherwise inaccessible cell membrane structures and long chain organic molecules. In this study the influence of hydrodynamic cavitation on sludge that was already digested for 30 days was investigated. The total biogas yield could indeed be increased. The effect of the backpressure behind the venturi tube on the yield could not yet be established.

  20. Shear viscosity, cavitation and hydrodynamics at LHC

    International Nuclear Information System (INIS)

    Bhatt, Jitesh R.; Mishra, Hiranmaya; Sreekanth, V.

    2011-01-01

    We study evolution of quark-gluon matter in the ultrarelativistic heavy-ion collisions within the frame work of relativistic second-order viscous hydrodynamics. In particular, by using the various prescriptions of a temperature-dependent shear viscosity to the entropy ratio, we show that the hydrodynamic description of the relativistic fluid becomes invalid due to the phenomenon of cavitation. For most of the initial conditions relevant for LHC, the cavitation sets in very early stage. The cavitation in this case is entirely driven by the large values of shear viscosity. Moreover we also demonstrate that the conformal terms used in equations of the relativistic dissipative hydrodynamic can influence the cavitation time.

  1. Some observations of tip-vortex cavitation

    Science.gov (United States)

    Arndt, R. E. A.; Arakeri, V. H.; Higuchi, H.

    1991-08-01

    Cavitation has been observed in the trailing vortex system of an elliptic platform hydrofoil. A complex dependence on Reynolds number and gas content is noted at inception. Some of the observations can be related to tension effects associated with the lack of sufficiently large-sized nuclei. Inception measurements are compared with estimates of pressure in the vortex obtained from LDV measurements of velocity within the vortex. It is concluded that a complete correlation is not possible without knowledge of the fluctuating levels of pressure in tip-vortex flows. When cavitation is fully developed, the observed tip-vortex trajectory flows. When cavitation is fully developed, the observed tip-vortex trajectory shows a surprising lack of dependence on any of the physical parameters varied, such as angle of attack, Reynolds number, cavitation number, and dissolved gas content.

  2. The limitation and coordination of CT and positron emission tomography in the diagnosis of pulmonary nodules

    International Nuclear Information System (INIS)

    Zhang Jin'e; Liang Changhong; Zhao Zhenjun; Wang Shuxia; Qiao Suixian; He Hui; Zhang Jia; Ru Guangteng

    2005-01-01

    Objective: To Analyze the limitation and coordination of CT and positron emission tomography (PET) in the diagnosis of pulmonary nodules. Methods: A retrospective study was undertaken in 118 patients with pulmonary nodules which had CT and PET scan. The interval between examinations of various imaging equipment was less than 2 weeks. The diameter of nodules ranged from 2 cm to 4 cm with an average of 2.7 cm. The nodules were proved as lung cancer by pathology in 85 cases and metastatic tumor in 2 cases, benign nodules in 31 cases, including 8 cases of tuberculosis, 6 cases of hamartoma, 6 cases of inflammatory pseudotumor, 4 cases of chronic nonspecific inflammation, 3 cases of inflammation granuloma, 2 cases of mycosis, 1 case of abscess, and 1 case of globular atelectasis. Results: 93 cases were correctly diagnosed and 25 cases were misdiagnosed with CT in 118 cases of pulmonary nodules. The misdiagnosis rate of CT was 21.2%. 12 cases of lung cancer were misdiagnosed as benign and 13 cases of benign nodules were misdiagnosed as lung cancer. 96 cases were correctly diagnosed and 22 cases were misdiagnosed with PET. The misdiagnosis rate of PET was 18.6%. 10 cases of malignant nodules were misdiagnosed as benign and 12 cases of benign nodules were misdiagnosed as lung cancer. 108 cases were correctly diagnosed and 10 cases were misdiagnosed with CT coordinated with PET. The misdiagnosis rate was 8.5%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT, PET, and CT coordinated with PET were 86.2%, 58.1%, 85.2%, 60.0%, 78.8% and 88.5%, 61.3%, 86.5%, 65.5%, 81.4%, and 97.7%, 74.2%, 91.4%, 92.0%, 91.5% respectively. The accuracy showed no significant difference between CT and PET (χ 2 =0.625, P=0.239), but there were significant difference between CT coordinated with PET and CT or PET (χ 2 =7.762 and 5.318, P=0.005 and 0021). Conclusion: The features of CT and PET in benign and malignant pulmonary nodules are partly

  3. Approaches to juxta-pleural nodule detection in CT images within the MAGIC-5 Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    De Nunzio, G., E-mail: giorgio.denunzio@unisalento.it [University of Salento, Materials Science Department and Istituto Nazionale di Fisica Nucleare (INFN), Lecce (Italy); Massafra, A. [University of Salento, Physics Department and Istituto Nazionale di Fisica Nucleare (INFN), Lecce (Italy); Cataldo, R. [University of Salento, Materials Science Department and Istituto Nazionale di Fisica Nucleare (INFN), Lecce (Italy); De Mitri, I.; Peccarisi, M. [University of Salento, Physics Department and Istituto Nazionale di Fisica Nucleare (INFN), Lecce (Italy); Fantacci, M.E. [University of Pisa, Physics Department and Istituto Nazionale di Fisica Nucleare (INFN), Pisa (Italy); Gargano, G. [University of Bari, Physics Department and Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Lopez Torres, E. [CEADEN, Havana (Cuba)

    2011-08-21

    This work is a part of the MAGIC-5 (Medical Applications on a Grid Infrastructure Connection) experiment of the Italian INFN (Istituto Nazionale di Fisica Nucleare). A simple CAD (Computer-Assisted Detection) system for juxta-pleural lung nodules in CT images is presented, with the purpose of comparing different 2D concavity-patching techniques and assessing the respective efficiency in locating nodules. After a short introduction on the motivation, and a review of some CAD systems for lung nodules already published by the MAGIC-5 Collaboration, the paper describes the main lines of this particular approach, giving preliminary results and comments. In our procedure, candidate nodules are identified by patching lung border concavities in a hierarchical multiscale framework. Once located, they are fed to an artificial neural network for false positive reduction. The system has a modular structure that easily allows the insertion of arbitrary border-smoothing functions for concavity detection and nodule searching. In this paper the {alpha}-hull and morphological closing are compared, proving the higher sensitivity of the former, which also appears computationally less heavy.

  4. The methods for detecting multiple small nodules from 3D chest X-ray CT images

    International Nuclear Information System (INIS)

    Hayase, Yosuke; Mekada, Yoshito; Mori, Kensaku; Toriwaki, Jun-ichiro; Natori, Hiroshi

    2004-01-01

    This paper describes a method for detecting small nodules, whose CT values and diameters are more than -600 Hounsfield unit (H.U.) and 2 mm, from three-dimensional chest X-ray CT images. The proposed method roughly consists of two submodules: initial detection of nodule candidates by discriminating between nodule regions and other regions such as blood vessels or bronchi using a shape feature computed from distance values inside the regions and reduction of false positive (FP) regions by using a minimum directional difference filter called minimum directional difference filter (Min-DD) changing its radius suit to the size of the initial candidates. The performance of the proposed method was evaluated by using seven cases of chest X-ray CT images including six abnormal cases where multiple lung cancers are observed. The experimental results for nodules (361 regions in total) showed that sensitivity and FP regions are 71% and 7.4 regions in average per case. (author)

  5. Detectability of pulmonary nodules with electronic collimation and conventional antiscatter grid

    International Nuclear Information System (INIS)

    Plenkovich, D.; Plavsic, B.; Robinson, A.E.; Lichtenstein, R.L.

    1989-01-01

    Electronic collimation is a method for rejection of scattered radiation and veiling glare in digital radiography. Digital images of a frozen, unembalmed, human chest phantom with simulated pulmonary nodules were obtained with use of the electronic collimation technique and a conventional 10:1 antiscatter grid. Observers were asked to locate multiple nodules and to record one of three levels of confidence. For each criterion, the total number of correct responses was divided by the total number of nodules to obtain the ordinate of a point. The total number of false-positive answers generated was divided by the number of images to obtain the abscissa of the point. The analysis was repeated for each scatter rejection method and for either the lungs or the mediastinum. The electronic collimation technique has improved the detectability of nodules projected over the mediastinum

  6. Multilevel binomial logistic prediction model for malignant pulmonary nodules based on texture features of CT image

    International Nuclear Information System (INIS)

    Wang Huan; Guo Xiuhua; Jia Zhongwei; Li Hongkai; Liang Zhigang; Li Kuncheng; He Qian

    2010-01-01

    Purpose: To introduce multilevel binomial logistic prediction model-based computer-aided diagnostic (CAD) method of small solitary pulmonary nodules (SPNs) diagnosis by combining patient and image characteristics by textural features of CT image. Materials and methods: Describe fourteen gray level co-occurrence matrix textural features obtained from 2171 benign and malignant small solitary pulmonary nodules, which belongs to 185 patients. Multilevel binomial logistic model is applied to gain these initial insights. Results: Five texture features, including Inertia, Entropy, Correlation, Difference-mean, Sum-Entropy, and age of patients own aggregating character on patient-level, which are statistically different (P < 0.05) between benign and malignant small solitary pulmonary nodules. Conclusion: Some gray level co-occurrence matrix textural features are efficiently descriptive features of CT image of small solitary pulmonary nodules, which can profit diagnosis of earlier period lung cancer if combined patient-level characteristics to some extent.

  7. The Role of Cavitation in Liposome Formation

    OpenAIRE

    Richardson, Eric S.; Pitt, William G.; Woodbury, Dixon J.

    2007-01-01

    Liposome size is a vital parameter of many quantitative biophysical studies. Sonication, or exposure to ultrasound, is used widely to manufacture artificial liposomes, yet little is known about the mechanism by which liposomes are affected by ultrasound. Cavitation, or the oscillation of small gas bubbles in a pressure-varying field, has been shown to be responsible for many biophysical effects of ultrasound on cells. In this study, we correlate the presence and type of cavitation with a decr...

  8. The role of cavitation in liposome formation.

    Science.gov (United States)

    Richardson, Eric S; Pitt, William G; Woodbury, Dixon J

    2007-12-15

    Liposome size is a vital parameter of many quantitative biophysical studies. Sonication, or exposure to ultrasound, is used widely to manufacture artificial liposomes, yet little is known about the mechanism by which liposomes are affected by ultrasound. Cavitation, or the oscillation of small gas bubbles in a pressure-varying field, has been shown to be responsible for many biophysical effects of ultrasound on cells. In this study, we correlate the presence and type of cavitation with a decrease in liposome size. Aqueous lipid suspensions surrounding a hydrophone were exposed to various intensities of ultrasound and hydrostatic pressures before measuring their size distribution with dynamic light scattering. As expected, increasing ultrasound intensity at atmospheric pressure decreased the average liposome diameter. The presence of collapse cavitation was manifested in the acoustic spectrum at high ultrasonic intensities. Increasing hydrostatic pressure was shown to inhibit the presence of collapse cavitation. Collapse cavitation, however, did not correlate with decreases in liposome size, as changes in size still occurred when collapse cavitation was inhibited either by lowering ultrasound intensity or by increasing static pressure. We propose a mechanism whereby stable cavitation, another type of cavitation present in sound fields, causes fluid shearing of liposomes and reduction of liposome size. A mathematical model was developed based on the Rayleigh-Plesset equation of bubble dynamics and principles of acoustic microstreaming to estimate the shear field magnitude around an oscillating bubble. This model predicts the ultrasound intensities and pressures needed to create shear fields sufficient to cause liposome size change, and correlates well with our experimental data.

  9. Diagnostic procedures of the solitary pulmonary nodule

    International Nuclear Information System (INIS)

    Aoe, Keisuke; Hiraki, Akio; Kohara, Hiroyuki

    2003-01-01

    The spread of computed tomography (CT) brought the frequent further examinations of the solitary pulmonary nodules (SPN). To aim the evaluation of initial data on examinations of SPN for differential diagnosis, we studied retrospective cases. Thirty-one cases of SPN less than 20 mm in diameter were compared in clinical findings and CT image findings and were examined the diagnostic procedures in recent three years in National Sanyo Hospital. The 31 patients consisted of 14 males and 17 females ranging 44 to 79 years old, median 65 years old. The causes of SPN were lung cancer (11 patients), cryptococcosis (4 patients), tuberculoma (3 patients), non-tuberculous mycobacteria (2 patients), pneumoconiosis (2 patients), pneumonia scar (one patient), hamartoma (one patient), and unknown (7 patients). There were no significant differences in laboratory findings between lung cancer and the others. CT findings showed significant differences in four categories. All patients underwent fiberoptic bronchoscopy (FB) examinations and 12 patients were determined the diagnosis initial FB. Five patients were established their diagnosis using videoassociated thoracoscopic surgeries. (author)

  10. Experimental investigation of cavitation induced air release

    Directory of Open Access Journals (Sweden)

    Kowalski Karoline

    2017-01-01

    Full Text Available Variations in cross-sectional areas may lead to pressure drops below a critical value, such that cavitation and air release are provoked in hydraulic systems. Due to a relatively slow dissolution of gas bubbles, the performance of hydraulic systems will be affected on long time scales by the gas phase. Therefore predictions of air production rates are desirable to describe the system characteristics. Existing investigations on generic geometries such as micro-orifice flows show an outgassing process due to hydrodynamic cavitation which takes place on time scales far shorter than diffusion processes. The aim of the present investigation is to find a correlation between global, hydrodynamic flow characteristics and cavitation induced undissolved gas fractions generated behind generic flow constrictions such as an orifice or venturi tube. Experimental investigations are realised in a cavitation channel that enables an independent adjustment of the pressure level upstream and downstream of the orifice. Released air fractions are determined by means of shadowgraphy imaging. First results indicate that an increased cavitation activity leads to a rapid increase in undissolved gas volume only in the choking regime. The frequency distribution of generated gas bubble size seems to depend only indirectly on the cavitation intensity driven by an increase of downstream coalescence events due to a more densely populated bubbly flow.

  11. Experimental investigation of cavitation induced air release

    Science.gov (United States)

    Kowalski, Karoline; Pollak, Stefan; Hussong, Jeanette

    Variations in cross-sectional areas may lead to pressure drops below a critical value, such that cavitation and air release are provoked in hydraulic systems. Due to a relatively slow dissolution of gas bubbles, the performance of hydraulic systems will be affected on long time scales by the gas phase. Therefore predictions of air production rates are desirable to describe the system characteristics. Existing investigations on generic geometries such as micro-orifice flows show an outgassing process due to hydrodynamic cavitation which takes place on time scales far shorter than diffusion processes. The aim of the present investigation is to find a correlation between global, hydrodynamic flow characteristics and cavitation induced undissolved gas fractions generated behind generic flow constrictions such as an orifice or venturi tube. Experimental investigations are realised in a cavitation channel that enables an independent adjustment of the pressure level upstream and downstream of the orifice. Released air fractions are determined by means of shadowgraphy imaging. First results indicate that an increased cavitation activity leads to a rapid increase in undissolved gas volume only in the choking regime. The frequency distribution of generated gas bubble size seems to depend only indirectly on the cavitation intensity driven by an increase of downstream coalescence events due to a more densely populated bubbly flow.

  12. Measuring Cavitation with Synchrotron X-Rays

    Science.gov (United States)

    Duke, Daniel; Kastengren, Alan; Powell, Chris; X-Ray Fuel Spray Group, Energy Systems Division Team

    2012-11-01

    Cavitation plays an important role in the formation of sprays from small nozzles such as those found in fuel injection systems. A sharp-edged inlet from the sac into the nozzle of a diesel fuel injector is shown to inititate a strong sheet-like cavitation along the boundary layer of the nozzle throat, which is difficult to measure and can lead to acoustic damage. To investigate this phenomenon, a diagnostic technique capable of mapping the density field of the nozzle through regions of intense cavitation is required. Available visible-light techniques are limited to qualitative observations of the outer extent of cavitation zones. However, brilliant X-rays from a synchrotron source have negligible refraction and are capable of penetrating the full extent of cavitation zones. We present the early results of a novel application of line-of-sight, time-resolved X-ray radiography on a cavitating model nozzle. Experiments were conducted at Sector 7-BM of the Advanced Photon Source. Density and vapor distribution are measured from the quantitative absorption of monochromatic X-rays. The density field can then be tomographically reconstructed from the projections. The density is then validated against a range of compressible and incompressible numerical simulations. This research was performed at the 7-BM beamline of the Advanced Photon Source. We acknowledge the support of the U.S. Department of Energy under Contract No. DE-AC02-06CH11357 and the DOE Vehicle Technologies Program (DOE-EERE).

  13. Observations on Rotating Cavitation and Cavitation Surge From The Development of the Fastrac Engine Turbopump

    Science.gov (United States)

    Zoladz, Thomas F.; Turner, James E. (Technical Monitor)

    2000-01-01

    The effects of rotating cavitation and cavitation surges on the Fastrac Engine Turbopump are described in a viewgraph presentation format. The bent inducer blade dilemma and observations of unsteady data and oscillation components are discussed. The pump-feed system stability modeling assessment is outlined. Recommendations are made urging further investigation.

  14. Research on a Pulmonary Nodule Segmentation Method Combining Fast Self-Adaptive FCM and Classification

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2015-01-01

    Full Text Available The key problem of computer-aided diagnosis (CAD of lung cancer is to segment pathologically changed tissues fast and accurately. As pulmonary nodules are potential manifestation of lung cancer, we propose a fast and self-adaptive pulmonary nodules segmentation method based on a combination of FCM clustering and classification learning. The enhanced spatial function considers contributions to fuzzy membership from both the grayscale similarity between central pixels and single neighboring pixels and the spatial similarity between central pixels and neighborhood and improves effectively the convergence rate and self-adaptivity of the algorithm. Experimental results show that the proposed method can achieve more accurate segmentation of vascular adhesion, pleural adhesion, and ground glass opacity (GGO pulmonary nodules than other typical algorithms.

  15. Host range, symbiotic effectiveness and nodulation competitiveness ...

    African Journals Online (AJOL)

    ERIC-PCR DNA fingerprinting patterns were used to identify the isolates occupying nodules. All the isolates nodulated cowpea, groundnut (Arachis hypogeae) and mungbean (Vigna radiata), but only AII-2-1, AII-3-4 and BIII-2-2 nodulated soybean (Glycine max). Apart from cowpea where all the isolates were effective, there ...

  16. Consistent interactive segmentation of pulmonary ground glass nodules identified in CT studies

    Science.gov (United States)

    Zhang, Li; Fang, Ming; Naidich, David P.; Novak, Carol L.

    2004-05-01

    Ground glass nodules (GGNs) have proved especially problematic in lung cancer diagnosis, as despite frequently being malignant they characteristically have extremely slow rates of growth. This problem is further magnified by the small size of many of these lesions now being routinely detected following the introduction of multislice CT scanners capable of acquiring contiguous high resolution 1 to 1.25 mm sections throughout the thorax in a single breathhold period. Although segmentation of solid nodules can be used clinically to determine volume doubling times quantitatively, reliable methods for segmentation of pure ground glass nodules have yet to be introduced. Our purpose is to evaluate a newly developed computer-based segmentation method for rapid and reproducible measurements of pure ground glass nodules. 23 pure or mixed ground glass nodules were identified in a total of 8 patients by a radiologist and subsequently segmented by our computer-based method using Markov random field and shape analysis. The computer-based segmentation was initialized by a click point. Methodological consistency was assessed using the overlap ratio between 3 segmentations initialized by 3 different click points for each nodule. The 95% confidence interval on the mean of the overlap ratios proved to be [0.984, 0.998]. The computer-based method failed on two nodules that were difficult to segment even manually either due to especially low contrast or markedly irregular margins. While achieving consistent manual segmentation of ground glass nodules has proven problematic most often due to indistinct boundaries and interobserver variability, our proposed method introduces a powerful new tool for obtaining reproducible quantitative measurements of these lesions. It is our intention to further document the value of this approach with a still larger set of ground glass nodules.

  17. Interscan variation of semi-automated volumetry of subsolid pulmonary nodules

    NARCIS (Netherlands)

    Scholten, Ernst Th; de Jong, Pim A.; Jacobs, Colin; van Ginneken, Bram; van Riel, Sarah; Willemink, Martin J.; Vliegenthart, Rozemarijn; Oudkerk, Matthijs; de Koning, Harry J.; Horeweg, Nanda; Prokop, Mathias; Mali, Willem P. Th. M.; Gietema, Hester A.

    We aimed to test the interscan variation of semi-automatic volumetry of subsolid nodules (SSNs), as growth evaluation is important for SSN management. From a lung cancer screening trial all SSNs that were stable over at least 3 months were included (N = 44). SSNs were quantified on the baseline CT

  18. Clinical chest CAD system for lung cancer, COPD, and osteoporosis based on MDCT images

    International Nuclear Information System (INIS)

    Matsuhiro, Mikio; Suzuki, Hidenobu; Saita, Shinsuke

    2011-01-01

    Lung cancer kills more people than any other cancer worldwide. Lung cancer screening using low-dose CT have been performed in many countries. Comparative reading of current and past CT images is important for evaluation of pulmonary nodules in lung cancer CT screening. However, primary problem in comparative reading is mismatch of slice and nodule positions caused by lung variation. It is hard for physicians to manually match slice positions, nodule positions, and evaluate the nodule's degree of change. A system to assist smooth comparative reading is necessary. We proposed a comparative reading system for lung cancer CT screening. A distinctive feature is highly accurate matching method of region of interest based on thoracic organs registration. Pulmonary blood vessels registration using analysis of the tree structure is performed. The system is evaluated by 1 mm and 2 mm slice thickness CT images obtained from lung cancer CT screening. We show how it is useful for lung cancer CT screening. (author)

  19. Ultralow dose CT for pulmonary nodule detection with chest X-ray equivalent dose - a prospective intra-individual comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Messerli, Michael [University Zurich, Department of Nuclear Medicine, University Hospital Zurich, Zurich (Switzerland); Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Kluckert, Thomas; Knitel, Meinhard; Desbiolles, Lotus; Bauer, Ralf W.; Wildermuth, Simon [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Waelti, Stephan [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); University of Montreal, Department of Radiology, CHU Sainte-Justine, Montreal, Quebec (Canada); Rengier, Fabian [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Warschkow, Rene [Cantonal Hospital St. Gallen, Department of Surgery, St. Gallen (Switzerland); Alkadhi, Hatem [University Zurich, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland); Leschka, Sebastian [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); University Zurich, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland)

    2017-08-15

    To prospectively evaluate the accuracy of ultralow radiation dose CT of the chest with tin filtration at 100 kV for pulmonary nodule detection. 202 consecutive patients undergoing clinically indicated chest CT (standard dose, 1.8 ± 0.7 mSv) were prospectively included and additionally scanned with an ultralow dose protocol (0.13 ± 0.01 mSv). Standard dose CT was read in consensus by two board-certified radiologists to determine the presence of lung nodules and served as standard of reference (SOR). Two radiologists assessed the presence of lung nodules and their locations on ultralow dose CT. Sensitivity and specificity of the ultralow dose protocol was compared against the SOR, including subgroup analyses of different nodule sizes and types. A mixed effects logistic regression was used to test for independent predictors for sensitivity of pulmonary nodule detection. 425 nodules (mean diameter 3.7 ± 2.9 mm) were found on SOR. Overall sensitivity for nodule detection by ultralow dose CT was 91%. In multivariate analysis, nodule type, size and patients BMI were independent predictors for sensitivity (p < 0.001). Ultralow dose chest CT at 100 kV with spectral shaping enables a high sensitivity for the detection of pulmonary nodules at exposure levels comparable to plain film chest X-ray. (orig.)

  20. Effect of hydrodynamic cavitation on zooplankton: A tool for disinfection

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Anil, A.C.; Venkat, K.; Gaonkar, C.; Kolwalkar, J.; Khandeparker, L.; Desai, D.V.; Mahulkar, A.V.; Ranade, V.V.; Pandit, A.B.

    by individual oscillating cavity, cell wall strength and geometrical and operating parameters of cavitation device. Theoretical model for quantifying the cavitationally generated turbulent shear and extent of microbial disinfection has been developed...

  1. Advanced experimental and numerical techniques for cavitation erosion prediction

    CERN Document Server

    Chahine, Georges; Franc, Jean-Pierre; Karimi, Ayat

    2014-01-01

    This book provides a comprehensive treatment of the cavitation erosion phenomenon and state-of-the-art research in the field. It is divided into two parts. Part 1 consists of seven chapters, offering a wide range of computational and experimental approaches to cavitation erosion. It includes a general introduction to cavitation and cavitation erosion, a detailed description of facilities and measurement techniques commonly used in cavitation erosion studies, an extensive presentation of various stages of cavitation damage (including incubation and mass loss), and insights into the contribution of computational methods to the analysis of both fluid and material behavior. The proposed approach is based on a detailed description of impact loads generated by collapsing cavitation bubbles and a physical analysis of the material response to these loads. Part 2 is devoted to a selection of nine papers presented at the International Workshop on Advanced Experimental and Numerical Techniques for Cavitation Erosion (Gr...

  2. Real-Time Two-Dimensional Imaging of Microbubble Cavitation

    NARCIS (Netherlands)

    Vignon, F.; Shi, W.T.; Powers, J.E.; Liu, J.; Drvol, L.; Lof, J.; Everbach, C.; Gao, S.; Xie, F.; Porter, T.

    2011-01-01

    Ultrasound cavitation of microbubble contrast agents has a potentialfor therapeutic applications, including sonothrombolysis in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (e.g. stable versus inertial forms of

  3. Persistent pulmonary subsolid nodules with solid portions of 5 mm or smaller: Their natural course and predictors of interval growth

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Hyuk [Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Department of Radiology, Seoul (Korea, Republic of); Park, Chang Min [Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Department of Radiology, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Duke University Medical Center, Department of Radiology, Durham, NC (United States); Lee, Sang Min [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology, Seoul (Korea, Republic of); Kim, Hyungjin [Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Department of Radiology, Seoul (Korea, Republic of); Air Force Education and Training Command, Aerospace Medical Group, Jinju (Korea, Republic of); McAdams, H.P. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Goo, Jin Mo [Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Department of Radiology, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of)

    2016-06-15

    To investigate the natural course of persistent pulmonary subsolid nodules (SSNs) with solid portions ≤5 mm and the clinico-radiological features that influence interval growth over follow-ups. From 2005 to 2013, the natural courses of 213 persistent SSNs in 213 patients were evaluated. To identify significant predictors of interval growth, Kaplan-Meier analysis and Cox proportional hazard regression analysis were performed. Among the 213 nodules, 136 were pure ground-glass nodules (GGNs; growth, 18; stable, 118) and 77 were part-solid GGNs with solid portions ≤5 mm (growth, 24; stable, 53). For all SSNs, lung cancer history (p = 0.001), part-solid GGNs (p < 0.001), and nodule diameter (p < 0.001) were significant predictors for interval growth. On subgroup analysis, nodule diameter was an independent predictor for the interval growth of both pure GGNs (p < 0.001), and part-solid GGNs (p = 0.037). For part-solid GGNs, lung cancer history (p = 0.002) was another significant predictor of the interval growth. Interval growth of pure GGNs ≥10 mm and part-solid GGNs ≥8 mm were significantly more frequent than in pure GGNs <10 mm (p < 0.001) and part-solid GGNs <8 mm (p = 0.003), respectively. The natural course of SSNs with solid portions ≤5 mm differed significantly according to their nodule type and nodule diameters, with which their management can be subdivided. (orig.)

  4. Solitary pulmonary nodule and {sup 18}F-FDG PET/CT. Part 1: epidemiology, morphological evaluation and cancer probability

    Energy Technology Data Exchange (ETDEWEB)

    Mosmann, Marcos Pretto; Borba, Marcelle Alves; Macedo, Francisco Pires Negromonte; Liguori, Adriano de Araujo Lima; Villarim Neto, Arthur, E-mail: mosmann@gmail.com [Liga Norte Riograndense Contra o Cancer, Natal, RN (Brazil); Lima, Kenio Costa de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Saude Coletiva

    2016-01-15

    Solitary pulmonary nodule corresponds to a common radiographic finding, which is frequently detected incidentally. The investigation of this entity remains complex, since characteristics of benign and malignant processes overlap in the differential diagnosis. Currently, many strategies are available to evaluate solitary pulmonary nodules with the main objective of characterizing benign lesions as best as possible, while avoiding to expose patients to the risks inherent to invasive methods, besides correctly detecting cases of lung cancer so as the potential curative treatment is not delayed. This first part of the study focuses on the epidemiology, the morphological evaluation and the methods to determine the likelihood of cancer in cases of indeterminate solitary pulmonary nodule. (author)

  5. Cavitational Hydrothermal Oxidation: A New Remediation Process - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Suslick, K. S.

    2001-07-05

    During the past year, we have continued to make substantial scientific progress on our understanding of cavitation phenomena in aqueous media and applications of cavitation to remediation processes. Our efforts have focused on three separate areas: sonoluminescence as a probe of conditions created during cavitational collapse in aqueous media, the use of cavitation for remediation of contaminated water, and an addition of the use of ultrasound in the synthesis of novel heterogeneous catalysts for hydrodehalogenation of halocarbons under mild conditions.

  6. Cavitational Hydrothermal Oxidation: A New Remediation Process - Final Report; FINAL

    International Nuclear Information System (INIS)

    Suslick, K. S.

    2001-01-01

    During the past year, we have continued to make substantial scientific progress on our understanding of cavitation phenomena in aqueous media and applications of cavitation to remediation processes. Our efforts have focused on three separate areas: sonoluminescence as a probe of conditions created during cavitational collapse in aqueous media, the use of cavitation for remediation of contaminated water, and an addition of the use of ultrasound in the synthesis of novel heterogeneous catalysts for hydrodehalogenation of halocarbons under mild conditions

  7. International symposium on cavitation and multiphase flow noise - 1986

    International Nuclear Information System (INIS)

    Arndt, R.E.A.; Billet, M.L.; Blake, W.K.

    1986-01-01

    This book presents the papers given at a symposium on multiphase flow and cavitation. Topics considered at the conference included the development of a cavitation-free sodium pump for a breeder reactor, the stochastic behavior (randomness) of acoustic pressure pulses in the near-subcavitating range, cavitation monitoring of two axial-flow hydroturbines, and noise generated by cavitation in orifice plates with some gaseous effects

  8. Actual status of sodium cavitation studies in Japan

    International Nuclear Information System (INIS)

    Yamamoto, K.; Kamiyama, S.; Hashimoto, H.; Mochizuki, K.; Nakai, Y.; Ishibashi, E.; Tamaoki, T.

    1976-01-01

    A cavitation test has been conducted on some components of the fast experimental reactor JOYO. Design is in progress for the fast proto-type reactor MONJU. Deliberate consideration has been taken against cavitation as this reactor will be operated under severer service conditions than that of JOYO. A cavitation test of entrance nozzles of MONJU fuel subassemblies was performed in water. In order to obtain design data a program of cavitation tests is planned

  9. Thyroid Nodule Imaging. Status and Limitations.

    Directory of Open Access Journals (Sweden)

    Durre Sabih

    2015-01-01

    Full Text Available Thyroid nodules are common, occurring in almost two-thirds of some populations; among these only about 7% are malignant. The most important question with any new discovered thyroid nodule is, “is this malignant?” The main arbiter of malignancy or benignity remains fine needle aspiration and the mainstay of treatment surgery. But given the resources involved, doing an FNAC or surgery in every discovered nodule would be prohibitive to impossible. The clinician must decide which nodule to investigate and which to watch in the hope that this will never turn out to be malignant. FNACs are used basically to decide which nodule to operate upon (or more importantly which to not operate upon and clinical and imaging features are used to decide which nodule to investigate by FNAC and which to leave alone. This paper describes the various imaging options for looking at thyroid nodules and briefly discusses the advantages and disadvantages with each.

  10. Lung inflammatory pseudo tumor

    International Nuclear Information System (INIS)

    Veliz, Elizabeth; Leone, Gaetano; Cano, Fernando; Sanchez, Jaime

    2005-01-01

    The inflammatory pseudo tumor is a non neoplastic process characterized by an irregular growth of inflammatory cells. We described the case of a 38 year-old patient, she went to our institute for a in situ cervix cancer and left lung nodule without breathing symptoms; valued by neumology who did bronchoscopy with biopsy whose result was negative for malignancy. She went to surgery in where we find intraparenquima nodule in felt lingula of approximately 4 cms, we remove it; the result was: Inflammatory pseudotumor. This pathology is a not very frequent, it can develop in diverse regions of the organism, it is frequent in lung. The image tests are not specific for the diagnose, which it is possible only with the biopsy. The treatment is the complete resection. (The author)

  11. Drag Reducing and Cavitation Resistant Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pease, Leonard F.

    2016-12-28

    Client, Green Building Systems (GBS), presented PNNL a coating reported to reduce drag and prevent cavitation damage on marine vessels, turbines and pumps. The composition of the coating remains proprietary but has as constituents including silicon oxides, aliphatic carbon chains, and fluorine rich particles. The coating is spray applied to surfaces. Prior GBS testing and experiments suggest reduction of both drag and cavitation on industrial scale propellers, but the underlying mechanism for these effects remains unclear. Yet, the application is compelling because even modest reductions in drag to marine vessels and cavitation to propellers and turbines present a significant economic and environmental opportunity. To discern among possible mechanisms, PNNL considered possible mechanisms with the client, executed multiple experiments, and completed one theoretical analysis (see appendix). The remainder of this report first considers image analysis to gain insight into drag reduction mechanisms and then exposes the coating to cavitation to explore its response to an intensely cavitating environment. Although further efforts may be warranted to confirm mechanisms, this report presents a first investigation into these coatings within the scope and resources of the technology assistance program (TAP).

  12. Modeling of hydrodynamic cavitation reactors: a unified approach

    NARCIS (Netherlands)

    Moholkar, V.S.; Pandit, A.B.

    2001-01-01

    An attempt has been made to present a unified theoretical model for the cavitating flow in a hydrodynamic cavitation reactor using the nonlinear continuum mixture model for two-phase flow as the basis. This model has been used to describe the radial motion of bubble in the cavitating flow in two

  13. Twin boundary cavitation in aged type 304 stainless steel

    International Nuclear Information System (INIS)

    Sikka, V.K.; Swindeman, R.W.; Brinkman, C.R.

    1975-10-01

    A transition from grain to twin boundary cavitation was observed in aged-and-creep-tested type 304 stainless steel. Evidence of twin boundary cavitation has also been observed for unaged material under certain test conditions. This same behavior was also found in aged type 316 stainless steel. Several possible reasons have been suggested for the absence of frequently observed grain boundary cavitation

  14. Cavitation erosion in a 400 deg. C sodium flow

    International Nuclear Information System (INIS)

    Courbiere, P.

    2002-01-01

    This paper presents the results of cavitation erosion tests conducted in the Cavitation Tunnel at the Cadarache Nuclear Research Center. The CANASTA system was used for acoustic monitoring of cavitation noise during the experiments. Comparative results are also presented for sodium and water tests. (author)

  15. Influence of microparticle size on cavitation noise during ultrasonic vibration

    Directory of Open Access Journals (Sweden)

    H. Ge

    2015-09-01

    Full Text Available The cavitation noise in the ultrasonic vibration system was found to be influenced by the size of microparticles added in water. The SiO2 microparticles with the diameter smaller than 100 μm reduced the cavitation noise, and the reason was attributed to the constrained oscillation of the cavitation bubbles, which were stabilized by the microparticles.

  16. Ultrasound guided percutaneous microwave ablation of benign thyroid nodules: Safety and imaging follow-up in 222 patients

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Wenwen [Binzhou Medical University, #346 Guan-hai Road, Lai-shan, Yantai, Shandong 264003 (China); Wang, Shurong, E-mail: 7762808@sina.com [Department of Ultrasound, Muping Area People' s Hospital, #629 Nan-hua Street, Mu-ping, Yantai, Shandong 264100 (China); Wang, Bin [Binzhou Medical University, #346 Guan-hai Road, Lai-shan, Yantai, Shandong 264003 (China); Xu, Qingling; Yu, Shoujun; Yonglin, Zhang; Wang, Xiju [Department of Ultrasound, Muping Area People' s Hospital, #629 Nan-hua Street, Mu-ping, Yantai, Shandong 264100 (China)

    2013-01-15

    Objective: Microwave ablation is a minimally invasive technique that has been used to treat benign and malignant tumors of liver, lung and kidney. Towards thyroid nodules, only a few cases are reported so far. The aim of the study was to investigate the effectiveness and safety of ultrasound-guided percutaneous microwave ablation in the treatment of benign thyroid nodules with a large sample. Materials and methods: A total of 477 benign thyroid nodules in 222 patients underwent microwave ablation in our department from July 2009 to March 2012. Microwave ablation was carried out using microwave antenna (16G) under local anesthesia. Nodule volume, thyroid function and clinical symptoms were evaluated before treatment and at 1, 3, more than 6 months. The study was ethics committee approved and written informed consents were obtained from all patients. Results: All thyroid nodules significantly decreased in size after microwave ablation. A 6-month follow-up was achieved in 254 of 477 nodules, and the mean decrease in the volume of thyroid nodules was from 2.13 ± 4.42 ml to 0.45 ± 0.90 ml, with a mean percent decrease of 0.65 ± 0.65. A volume-reduction ratio greater than 50% was observed in 82.3% (209/254) of index nodules, and 30.7% (78/254) of index nodules disappeared 6-month after the ablation. The treatment was well tolerated and no major complications were observed except pain and transient voice changes. Conclusions: Microwave ablation seems to be a safe and effective technique for the treatment of benign thyroid nodules. Further prospective randomized studies are needed to define the role of the procedure in the treatment of thyroid nodules.

  17. The issue of cavitation number value in studies of water treatment by hydrodynamic cavitation.

    Science.gov (United States)

    Šarc, Andrej; Stepišnik-Perdih, Tadej; Petkovšek, Martin; Dular, Matevž

    2017-01-01

    Within the last years there has been a substantial increase in reports of utilization of hydrodynamic cavitation in various applications. It has came to our attention that many times the results are poorly repeatable with the main reason being that the researchers put significant emphasis on the value of the cavitation number when describing the conditions at which their device operates. In the present paper we firstly point to the fact that the cavitation number cannot be used as a single parameter that gives the cavitation condition and that large inconsistencies in the reports exist. Then we show experiments where the influences of the geometry, the flow velocity, the medium temperature and quality on the size, dynamics and aggressiveness of cavitation were assessed. Finally we show that there are significant inconsistencies in the definition of the cavitation number itself. In conclusions we propose a number of parameters, which should accompany any report on the utilization of hydrodynamic cavitation, to make it repeatable and to enable faster progress of science and technology development. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. CT-guided localization of small pulmonary nodules using adjacent microcoil implantation prior to video-assisted thoracoscopic surgical resection

    Energy Technology Data Exchange (ETDEWEB)

    Su, Tian-Hao; Jin, Long; He, Wen [Capital Medical University, Department of Radiology, Beijing Friendship Hospital, Beijing (China); Fan, Yue-Feng [Xiamen University, Department of Interventional Therapy, The First Affiliated Hospital, Xiamen, Fujian (China); Hu, Li-Bao [Peking University People' s Hospital, Department of Radiology, Beijing (China)

    2015-09-15

    To describe and assess the localization of small peripheral pulmonary nodules prior to video-assisted thoracoscopic surgical (VATS) resection using the implantation of microcoils. Ninety-two patients with 101 pulmonary nodules underwent computed tomography (CT)-guided implantation of microcoils proximal to each nodule. Patients were randomly assigned to undergo entire microcoil or leaving-microcoil-end implantations. The complications and efficacy of the two implantation methods were evaluated. VATS resection of lung tissue containing each pulmonary lesion and microcoil were performed in the direction of the microcoil marker. Histopathological analysis was performed for the resected pulmonary lesions. CT-guided microcoil implantation was successful in 99/101 cases, and the placement of microcoils within 1 cm of the nodules was not disruptive. There was no difference in the complications and efficacy associated with the entire implantation method (performed for 51/99 nodules) versus the leaving-microcoil-end implantation method (performed for 48/99 nodules). All nodules were successfully removed using VATS resection. Asymptomatic pneumothorax occurred in 16 patients and mild pulmonary haemorrhage occurred in nine patients. However, none of these patients required further surgical treatment. Preoperative localization of small pulmonary nodules using a refined percutaneous microcoil implantation method was found to be safe and useful prior to VATS resection. (orig.)

  19. Rheumatoid arthritis and pulmonary nodules: An unexpected final diagnosis.

    Science.gov (United States)

    Zurita Prada, Pablo Antonio; Urrego Laurín, Claudia Lía; Assyaaton Bobo, Sow; Faré García, Regina; Estrada Trigueros, Graciliano; Gallardo Romero, José Manuel; Borrego Pintado, Maria Henar

    We report the case of a 50-year-old female smoker with an 11-year history of seropositive rheumatoid arthritis (rheumatoid factor and anti-cyclic citrullinated peptide antibodies) receiving triple therapy. She developed pulmonary nodules diagnosed as Langerhans cell histiocytosis by lung biopsy. We found no reported cases of the coexistence of these two diseases. Smoking abstinence led to radiologic resolution without modifying the immunosuppressive therapy. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  20. Miliary nodules in a patient of allergic bronchopulmonary aspergilosis.

    Science.gov (United States)

    Khan, N A; Sumon, S M; Rahman, A; Hossain, M A; Ferdous, J; Bari, M R

    2014-04-01

    Allergic bronchopulmonary aspergilosis (ABPA) is immunological pulmonary disease caused by hypersensitivity of aspergillus fumigatus usually occurs in patients with chronic asthma, cystic fibrosis and bronchiactasis. This disease may present with divers radiological presentation like; fleeting pulmonary opacities, bronchiactasis, mucoid impaction, perihilar opacity (hailer lymphadenopathy), and lung mass or pleural effusion. We describe the case of a 30 year old housewife who presented with progressive dysponea, low grade fever, dry cough, weight loss and miliary nodule in chest radiograph and high-resolution CT (HRCT) in a tertiary level hospital of Bangladesh. A diagnosis of ABPA was established on the basis of sputum routine microscopy and culture examination for fungus (Aspergillus).

  1. European randomized lung cancer screening trials: Post NLST

    DEFF Research Database (Denmark)

    Field, JK; Klaveren, R; Pedersen, JH

    2013-01-01

    Overview of the European randomized lung cancer CT screening trials (EUCT) is presented with regard to the implementation of CT screening in Europe; post NLST. All seven principal investigators completed a questionnaire on the epidemiological, radiological, and nodule management aspects...

  2. Staging by tomography: Lung, esophagus, mama and pleural cancer

    International Nuclear Information System (INIS)

    Gigirey, V.

    2012-01-01

    This presentation shows images of different types of cancer in the lung, esophagus, mama and pleura. The chest radiography, computed tomography, magnetic resonance and PET CT contribute to detect the morphology, size, location, metastasize, malignant and benign nodules, lymph glands.

  3. Robust semi-automatic segmentation of pulmonary subsolid nodules in chest computed tomography scans

    International Nuclear Information System (INIS)

    Lassen, B C; Kuhnigk, J-M; Van Ginneken, B; Van Rikxoort, E M; Jacobs, C

    2015-01-01

    The malignancy of lung nodules is most often detected by analyzing changes of the nodule diameter in follow-up scans. A recent study showed that comparing the volume or the mass of a nodule over time is much more significant than comparing the diameter. Since the survival rate is higher when the disease is still in an early stage it is important to detect the growth rate as soon as possible. However manual segmentation of a volume is time-consuming. Whereas there are several well evaluated methods for the segmentation of solid nodules, less work is done on subsolid nodules which actually show a higher malignancy rate than solid nodules. In this work we present a fast, semi-automatic method for segmentation of subsolid nodules. As minimal user interaction the method expects a user-drawn stroke on the largest diameter of the nodule. First, a threshold-based region growing is performed based on intensity analysis of the nodule region and surrounding parenchyma. In the next step the chest wall is removed by a combination of a connected component analyses and convex hull calculation. Finally, attached vessels are detached by morphological operations. The method was evaluated on all nodules of the publicly available LIDC/IDRI database that were manually segmented and rated as non-solid or part-solid by four radiologists (Dataset 1) and three radiologists (Dataset 2). For these 59 nodules the Jaccard index for the agreement of the proposed method with the manual reference segmentations was 0.52/0.50 (Dataset 1/Dataset 2) compared to an inter-observer agreement of the manual segmentations of 0.54/0.58 (Dataset 1/Dataset 2). Furthermore, the inter-observer agreement using the proposed method (i.e. different input strokes) was analyzed and gave a Jaccard index of 0.74/0.74 (Dataset 1/Dataset 2). The presented method provides satisfactory segmentation results with minimal observer effort in minimal time and can reduce the inter-observer variability for segmentation of

  4. Robust semi-automatic segmentation of pulmonary subsolid nodules in chest computed tomography scans

    Science.gov (United States)

    Lassen, B. C.; Jacobs, C.; Kuhnigk, J.-M.; van Ginneken, B.; van Rikxoort, E. M.

    2015-02-01

    The malignancy of lung nodules is most often detected by analyzing changes of the nodule diameter in follow-up scans. A recent study showed that comparing the volume or the mass of a nodule over time is much more significant than comparing the diameter. Since the survival rate is higher when the disease is still in an early stage it is important to detect the growth rate as soon as possible. However manual segmentation of a volume is time-consuming. Whereas there are several well evaluated methods for the segmentation of solid nodules, less work is done on subsolid nodules which actually show a higher malignancy rate than solid nodules. In this work we present a fast, semi-automatic method for segmentation of subsolid nodules. As minimal user interaction the method expects a user-drawn stroke on the largest diameter of the nodule. First, a threshold-based region growing is performed based on intensity analysis of the nodule region and surrounding parenchyma. In the next step the chest wall is removed by a combination of a connected component analyses and convex hull calculation. Finally, attached vessels are detached by morphological operations. The method was evaluated on all nodules of the publicly available LIDC/IDRI database that were manually segmented and rated as non-solid or part-solid by four radiologists (Dataset 1) and three radiologists (Dataset 2). For these 59 nodules the Jaccard index for the agreement of the proposed method with the manual reference segmentations was 0.52/0.50 (Dataset 1/Dataset 2) compared to an inter-observer agreement of the manual segmentations of 0.54/0.58 (Dataset 1/Dataset 2). Furthermore, the inter-observer agreement using the proposed method (i.e. different input strokes) was analyzed and gave a Jaccard index of 0.74/0.74 (Dataset 1/Dataset 2). The presented method provides satisfactory segmentation results with minimal observer effort in minimal time and can reduce the inter-observer variability for segmentation of

  5. Multilevel Contextual 3-D CNNs for False Positive Reduction in Pulmonary Nodule Detection.

    Science.gov (United States)

    Dou, Qi; Chen, Hao; Yu, Lequan; Qin, Jing; Heng, Pheng-Ann

    2017-07-01

    False positive reduction is one of the most crucial components in an automated pulmonary nodule detection system, which plays an important role in lung cancer diagnosis and early treatment. The objective of this paper is to effectively address the challenges in this task and therefore to accurately discriminate the true nodules from a large number of candidates. We propose a novel method employing three-dimensional (3-D) convolutional neural networks (CNNs) for false positive reduction in automated pulmonary nodule detection from volumetric computed tomography (CT) scans. Compared with its 2-D counterparts, the 3-D CNNs can encode richer spatial information and extract more representative features via their hierarchical architecture trained with 3-D samples. More importantly, we further propose a simple yet effective strategy to encode multilevel contextual information to meet the challenges coming with the large variations and hard mimics of pulmonary nodules. The proposed framework has been extensively validated in the LUNA16 challenge held in conjunction with ISBI 2016, where we achieved the highest competition performance metric (CPM) score in the false positive reduction track. Experimental results demonstrated the importance and effectiveness of integrating multilevel contextual information into 3-D CNN framework for automated pulmonary nodule detection in volumetric CT data. While our method is tailored for pulmonary nodule detection, the proposed framework is general and can be easily extended to many other 3-D object detection tasks from volumetric medical images, where the targeting objects have large variations and are accompanied by a number of hard mimics.

  6. Large eddy simulation of cavitating flows

    Science.gov (United States)

    Gnanaskandan, Aswin; Mahesh, Krishnan

    2014-11-01

    Large eddy simulation on unstructured grids is used to study hydrodynamic cavitation. The multiphase medium is represented using a homogeneous equilibrium model that assumes thermal equilibrium between the liquid and the vapor phase. Surface tension effects are ignored and the governing equations are the compressible Navier Stokes equations for the liquid/vapor mixture along with a transport equation for the vapor mass fraction. A characteristic-based filtering scheme is developed to handle shocks and material discontinuities in non-ideal gases and mixtures. A TVD filter is applied as a corrector step in a predictor-corrector approach with the predictor scheme being non-dissipative and symmetric. The method is validated for canonical one dimensional flows and leading edge cavitation over a hydrofoil, and applied to study sheet to cloud cavitation over a wedge. This work is supported by the Office of Naval Research.

  7. String cavitation formation inside fuel injectors

    Science.gov (United States)

    Reid, B. A.; Gavaises, M.; Mitroglou, N.; Hargrave, G. K.; Garner, C. P.; McDavid, R. M.

    2015-12-01

    The formation of vortex or ‘string’ cavitation has been visualised at pressures up to 2000 bar in an automotive-sized optical diesel fuel injector nozzle. The multi-hole nozzle geometry studied allowed observation of the hole-to-hole vortex interaction and, in particular, that of a bridging vortex in the sac region between the holes. Above a threshold Reynolds number, their formation and appearance during a 2 ms injection event was repeatable and independent of upstream pressure and cavitation number. In addition, two different hole layouts and threedimensional flow simulations have been employed to describe how, the relative positions of adjacent holes influenced the formation and hole-to-hole interaction of the observed string cavitation vortices, with good agreement between the experimental and simulation results being achieved.

  8. Cavitation research from an intetrnational perspective

    International Nuclear Information System (INIS)

    Arndt, R E A

    2012-01-01

    This paper reviews some current research at the Saint Anthony Falls Laboratory from the perspective of the experience gained from cooperative research in other laboratories that the author has had the opportunity to participate in for several decades. Examples are drawn from the author's experience with collaborative efforts in China, Germany, Japan, Netherlands, Norway, and the US. Emphasis is placed on the progress in our understanding of the physics of cavitation as influenced by water quality, i.e. the strength of the water as influenced by the concentration of free and dissolved gas and complex fluid dynamic factors such as turbulence. The shift from experimental research to studies involving an integrated experimental/numerical approach is also underscored. Examples are drawn from early studies of inception and acoustics, vortex cavitation and more recent research on sheet/cloud cavitation and supercavitation. Some thoughts on new directions are also presented.

  9. Control of superplastic cavitation by hydrostatic pressure

    International Nuclear Information System (INIS)

    Bampton, C.C.; Ghosh, A.K.; Hamilton, C.H.; Mahoney, M.W.; Raj, R.

    1983-01-01

    It has been shown that the application of hydrostatic gas pressures during superplastic deformation of fine grained 7475 Al can prevent the intergranular cavitation normally encountered at atmospheric pressure. A critical ratio of hydrostatic pressure to flow stress may be defined for each superplastic forming condition above which virtually no cavitation occurs. In deformation conditions where intergranular cavitation plays a significant part in final tensile rupture, superplastic ductility may be improved by the application of hydrostatic pressures. Similarly, detrimental effects of large superplastic strains on service properties may be reduced or eliminated by the application of suitable hydrostatic pressures during superplastic forming. In this case, superplastically formed material may have the same design allowables as conventional 7475 Al sheet

  10. Telomerase in lung cancer diagnostics

    International Nuclear Information System (INIS)

    Kovkarova, E.; Stefanovski, T.; Dimov, A.; Naumovski, J.

    2003-01-01

    Background. Telomerase is a ribonucleoprotein that looks after the telomeric cap of the linear chromosomes maintaining its length. It is over expressed in tumour tissues, but not in normal somatic cells. Therefore the aim of this study was to determine the telomerase activity in lung cancer patients as novel marker for lung cancer detection evaluating the influence of tissue/cell obtaining technique. Material and methods. Using the TRAP (telomeric repeat amplification protocol), telomerase activity was determined in material obtained from bronchobiopsy (60 lung cancer patients compared with 20 controls) and washings from transthoracic fine needle aspiration biopsy performed in 10 patients with peripheral lung tumours. Results. Telomerase activity was detected in 75% of the lung cancer bronchobyopsies, and in 100% in transthoracic needle washings. Conclusions. Measurement of telomerase activity can contribute in fulfilling the diagnosis of lung masses and nodules suspected for lung cancer. (author)

  11. 10Be in manganese nodules

    International Nuclear Information System (INIS)

    Thomas, J.; Parker, P.; Mangini, A.; Cochran, K.; Turekian, K.; Krishnaswami, S.; Sharma, P.

    1981-01-01

    10 Be (t/sub 1/2) = 1.5 MY) is(formed in the upper atmosphere by cosmic ray spallation on nitrogen and oxygen. It is transported to the earth's surface via precipitation. In the oceans it is eventually associated with solid phases depositing on the ocean floor such as manganese nodules and deep-sea sediments. One of the assumptions that is normally made in analysis of such processes is that 10 Be has been produced at a relatively uniform rate over the pat several million years. If we assume, in addition, that the initial specific concentration of 10 Be as it precipitates with a solid phase is invariant with time, then we would expect that the decrease of the 10 Be concentration as a function of depth in a deep-sea core or in a manganese nodule would provide a record of sediment accumulation rate in the former and of growth rate in the latter. The possibility of using cosmic-ray produced 10 Be for the dating of marine deposits had been proposed 25 years ago by Arnold and Goel et al. The method of analysis used by these investigators, and those subsequently pursuing the problem, was low-level β counting. Though the potential of using 10 Be for dating manganese nodules was explored more than a decade ago, only a few measurements of 10 Be in nodules exist in date. This is largely because of the 10 Be measurements in environmental samples have gained considerable momentum during the past 3 to 4 years, after the development of accelerator mass spectrometry for its determination

  12. Strategy for polymetallic nodule mining

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.

    in industrializing their economies. Of the known mineral reselVcs these countries have nearly 50% of the nickel resclVcs, over 50% ofcopper reselVcs, 75% ofcobalt reserves, and aboul 25% of manganese reserves, and are major suppliers to the world markets... of these minerals. These counlries face the comhined effect oflosl markets and reduced price levels broughlabout by deep seabed nodule production. They depend on revenue earned from mineral exports more than do developed nations and have less flexibility...

  13. Numerical simulation of the cavitation's hydrodynamic excitement

    International Nuclear Information System (INIS)

    Hassis, H.; Dueymes, E.; Lauro, J.F.

    1993-01-01

    First, we study the motion, the velocity, the phases plane and the acoustic sources associated to a spherical bubble in a compressible or incompressible medium. The bubble can be excited by periodic or random excitements. We study the parameters which influence their behaviour: periodicity or not of motion, implosion and explosion or oscillation of bubble. We take into account this behaviour in a model of cavitation: it is a numerical simulation using population of bubbles which are with positions (in the cavitation volume) and sizes are random. These bubbles are excited by a random excitement: a model of turbulent flow or implosion and explosion of bubble. (author)

  14. Cavitation in holographic sQGP

    Energy Technology Data Exchange (ETDEWEB)

    Klimek, Aleksandra [Department of Physics, University of Warsaw (Poland); Leblond, Louis [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Sinha, Aninda, E-mail: asinha@cts.iisc.ernet.in [Centre for High Energy Physics, Indian Institute of Science, C.V. Raman Avenue, Bangalore 560012 (India)

    2011-06-27

    We study the possibility of cavitation in the non-conformal N=2{sup *}SU(N) theory which is a mass deformation of N=4SU(N) Yang-Mills theory. The second order transport coefficients are known from the numerical work using AdS/CFT by Buchel and collaborators. Using these and the approach of Rajagopal and Tripuraneni, we investigate the flow equations in a (1+1)-dimensional boost invariant set up. We find that the string theory model does not exhibit cavitation before phase transition is reached. We give a semi-analytic explanation of this finding.

  15. Determination of acoustic characteristics of pipe cavitation

    International Nuclear Information System (INIS)

    Loof, J.-P. de; Leducq, Daniel

    1979-01-01

    The subject of this report is an experimental investigation of cavitation as a source of noise within the audible and dangerous frequency ranges for industrial plant and equipment. The first results showed the noise-generating process to be comparable to that of a shock wave developing immediately after the cavitation area, propagating at very close to flow velocity and dying-down after a length equivalent to two or three diameters. Most of the energy is concentrated in the low-frequency range of the spectrum (i.e. up to 200 Hz) [fr

  16. Experimental investigation of hydrodynamic cavitation through orifices of different geometries

    Science.gov (United States)

    Rudolf, Pavel; Kubina, Dávid; Hudec, Martin; Kozák, Jiří; Maršálek, Blahoslav; Maršálková, Eliška; Pochylý, František

    Hydrodynamic cavitation in single and multihole orifices was experimentally investigated to assess their hydraulic characteristics: loss coefficients, inception cavitation number, cavitation number for transition to supercavitation. Significant difference for singlehole and multihole orifices was observed in terms of the measured loss coefficient. It is significantly more effective to use multihole orifices, where energy dissipation is much lower.It was found that using scaling factor given by ratio of orifice thickness suggests linear behaviour of both loss coefficient and inception cavitation number. Orifices seem to be convenient choice as flow constriction devices inducing cavitation due to their simplicity.

  17. Experimental investigation of hydrodynamic cavitation through orifices of different geometries

    Directory of Open Access Journals (Sweden)

    Rudolf Pavel

    2017-01-01

    Full Text Available Hydrodynamic cavitation in single and multihole orifices was experimentally investigated to assess their hydraulic characteristics: loss coefficients, inception cavitation number, cavitation number for transition to supercavitation. Significant difference for singlehole and multihole orifices was observed in terms of the measured loss coefficient. It is significantly more effective to use multihole orifices, where energy dissipation is much lower.It was found that using scaling factor given by ratio of orifice thickness suggests linear behaviour of both loss coefficient and inception cavitation number. Orifices seem to be convenient choice as flow constriction devices inducing cavitation due to their simplicity.

  18. Pulmonary nodule characterization: A comparison of conventional with quantitative and visual semi-quantitative analyses using contrast enhancement maps

    International Nuclear Information System (INIS)

    Petkovska, Iva; Shah, Sumit K.; McNitt-Gray, Michael F.; Goldin, Jonathan G.; Brown, Matthew S.; Kim, Hyun J.; Brown, Kathleen; Aberle, Denise R.

    2006-01-01

    Purpose: To determine whether conventional nodule densitometry or analysis based on contrast enhancement maps of indeterminate lung nodules imaged with contrast-enhanced CT can distinguish benign from malignant lung nodules. Materials and method: Thin section, contrast-enhanced CT (baseline, and post-contrast series acquired at 45, 90,180, and 360 s) was performed on 29 patients with indeterminate lung nodules (14 benign, 15 malignant). A thoracic radiologist identified the boundary of each nodule using semi-automated contouring to form a 3D region-of-interest (ROI) on each image series. The post-contrast series having the maximum mean enhancement was then volumetrically registered to the baseline series. The two series were subtracted volumetrically and the subtracted voxels were quantized into seven color-coded bins, forming a contrast enhancement map (CEM). Conventional nodule densitometry was performed to obtain the maximum difference in mean enhancement values for each nodule from a circular ROI. Three thoracic radiologists performed visual semi-quantitative analysis of each nodule, scoring each map for: (a) magnitude and (b) heterogeneity of enhancement throughout the entire volume of the nodule on a five-point scale. Receiver operator characteristic (ROC) analysis was conducted on these features to evaluate their diagnostic efficacy. Finally, 14 quantitative texture features were calculated for each map. A statistical analysis was performed to combine the 14 texture features to a single factor. ROC analysis of the derived aggregate factor was done as an indicator of malignancy. All features were analyzed for differences between benign and malignant nodules. Results: Using 15 HU as a threshold, 93% (14/15) of malignant and 79% (11/14) of benign nodules demonstrated enhancement. The ROC curve when higher values of enhancement indicate malignancy was generated and area under the curve (AUC) was 0.76. The visually scored magnitude of enhancement was found to be

  19. Automated computerized scheme for distinction between benign and malignant solitary pulmonary nodules on chest images

    International Nuclear Information System (INIS)

    Aoyama, Masahito; Li Qiang; Katsuragawa, Shigehiko; MacMahon, Heber; Doi, Kunio

    2002-01-01

    A novel automated computerized scheme has been developed to assist radiologists for their distinction between benign and malignant solitary pulmonary nodules on chest images. Our database consisted of 55 chest radiographs (33 primary lung cancers and 22 benign nodules). In this method, the location of a nodule was indicated first by a radiologist. The difference image with a nodule was produced by use of filters and then represented in a polar coordinate system. The nodule was segmented automatically by analysis of contour lines of the gray-level distribution based on the polar-coordinate representation. Two clinical parameters (age and sex) and 75 image features were determined from the outline, the image, and histogram analysis for inside and outside regions of the segmented nodule. Linear discriminant analysis (LDA) and knowledge about benign and malignant nodules were used to select initial feature combinations. Many combinations for subgroups of 77 features were evaluated as input to artificial neural networks (ANNs). The performance of ANNs with the selected 7 features by use of the round-robin test showed Az=0.872, which was greater than Az=0.854 obtained previously with the manual method (P=0.53). The performance of LDA (Az=0.886) was slightly improved compared to that of ANNs (P=0.59) and was greater than that of the manual method (Az=0.854) reported previously (P=0.40). The high level of its performance indicates the potential usefulness of this automated computerized scheme in assisting radiologists as a second opinion for distinction between benign and malignant solitary pulmonary nodules on chest images

  20. An Unusual Radiologic Pattern of Cryptogenic Organizing Pneumonia: Diffuse Pulmonary Nodules in a Leukemia Patient

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kai Hsiung; Hsu, Hsian He; Kao, Woei Yau; Chang, Ching Feng; Cheng, Ming Fang; Huang, Guo Shu [Tri-Service General Hospital, Taipei (China)

    2009-02-15

    The radiological appearance of diffuse discrete pulmonary nodules associated with cryptogenic organizing pneumonia (COP) has been rarely described. We describe a case of COP in 49-year-old woman with acute myeloid leukemia who developed diffuse pulmonary nodules during the second course of induction chemotherapy. The clinical status of the patient and imaging findings suggested the presence of a pulmonary metastasis or infectious disease. A video-assisted thoracoscopic lung biopsy resulted in the unexpected diagnosis of COP as an isolated entity. Steroid therapy led to dramatic improvement of the clinical symptoms and the pulmonary lesions.

  1. Seasonality of cavitation and frost fatigue in Acer mono Maxim.

    Science.gov (United States)

    Zhang, Wen; Feng, Feng; Tyree, Melvin T

    2017-12-08

    Although cavitation is common in plants, it is unknown whether the cavitation resistance of xylem is seasonally constant or variable. We tested the changes in cavitation resistance of Acer mono before and after a controlled cavitation-refilling and freeze-thaw cycles for a whole year. Cavitation resistance was determined from 'vulnerability curves' showing the percent loss of conductivity versus xylem tension. Cavitation fatigue was defined as a reduction of cavitation resistance following a cavitation-refilling cycle, whereas frost fatigue was caused by a freeze-thaw cycle. A. mono developed seasonal changes in native embolisms; values were relatively high during winter but relatively low and constant throughout the growing season. Cavitation fatigue occurred and changed seasonally during the 12-month cycle; the greatest fatigue response occurred during summer and the weakest during winter, and the transitions occurred during spring and autumn. A. mono was highly resistant to frost damage during the relatively mild winter months; however, a quite different situation occurred during the growing season, as the seasonal trend of frost fatigue was strikingly similar to that of cavitation fatigue. Seasonality changes in cavitation resistance may be caused by seasonal changes in the mechanical properties of the pit membranes. © 2017 John Wiley & Sons Ltd.

  2. Computer-aided diagnosis of pulmonary nodules on CT scans: Segmentation and classification using 3D active contours

    International Nuclear Information System (INIS)

    Way, Ted W.; Hadjiiski, Lubomir M.; Sahiner, Berkman; Chan, H.-P.; Cascade, Philip N.; Kazerooni, Ella A.; Bogot, Naama; Zhou Chuan

    2006-01-01

    We are developing a computer-aided diagnosis (CAD) system to classify malignant and benign lung nodules found on CT scans. A fully automated system was designed to segment the nodule from its surrounding structured background in a local volume of interest (VOI) and to extract image features for classification. Image segmentation was performed with a three-dimensional (3D) active contour (AC) method. A data set of 96 lung nodules (44 malignant, 52 benign) from 58 patients was used in this study. The 3D AC model is based on two-dimensional AC with the addition of three new energy components to take advantage of 3D information: (1) 3D gradient, which guides the active contour to seek the object surface (2) 3D curvature, which imposes a smoothness constraint in the z direction, and (3) mask energy, which penalizes contours that grow beyond the pleura or thoracic wall. The search for the best energy weights in the 3D AC model was guided by a simplex optimization method. Morphological and gray-level features were extracted from the segmented nodule. The rubber band straightening transform (RBST) was applied to the shell of voxels surrounding the nodule. Texture features based on run-length statistics were extracted from the RBST image. A linear discriminant analysis classifier with stepwise feature selection was designed using a second simplex optimization to select the most effective features. Leave-one-case-out resampling was used to train and test the CAD system. The system achieved a test area under the receiver operating characteristic curve (A z ) of 0.83±0.04. Our preliminary results indicate that use of the 3D AC model and the 3D texture features surrounding the nodule is a promising approach to the segmentation and classification of lung nodules with CAD. The segmentation performance of the 3D AC model trained with our data set was evaluated with 23 nodules available in the Lung Image Database Consortium (LIDC). The lung nodule volumes segmented by the 3D AC

  3. Appearance of high submerged cavitating jet: The cavitation phenomenon and sono luminescence

    Directory of Open Access Journals (Sweden)

    Hutli Ezddin

    2013-01-01

    Full Text Available In order to study jet structure and behaviour of cloud cavitation within time and space, visualization of highly submerged cavitating water jet has been done using Stanford Optics 4 Quick 05 equipment, through endoscopes and other lenses with Drello3244 and Strobex Flash Chadwick as flashlight stroboscope. This included obligatory synchronization with several types of techniques and lenses. Images of the flow regime have been taken, allowing calculation of the non-dimensional cavitation cloud length under working conditions. Consequently a certain correlation has been proposed. The influencing parameters, such as; injection pressure, downstream pressure and cavitation number were experimentally proved to be very significant. The recordings of sono-luminescence phenomenon proved the collapsing of bubbles everywhere along the jet trajectory. In addition, the effect of temperature on sono-luminescence recordings was also a point of investigation. [Projekat Ministarstva nauke Republike Srbije, br. TR35046

  4. FOREWORD: International Symposium of Cavitation and Multiphase Flow (ISCM 2014)

    Science.gov (United States)

    Wu, Yulin

    2015-01-01

    The International Symposium on Cavitation and Multiphase Flow (ISCM 2014) was held in Beijing, China during 18th-21st October, 2014, which was jointly organized by Tsinghua University, Beijing, China and Jiangsu University, Zhenjiang, China. The co-organizer was the State Key Laboratory of Hydroscience and Engineering, Beijing, China. Cavitation and multiphase flow is one of paramount topics of fluid mechanics with many engineering applications covering a broad range of topics, e.g. hydraulic machinery, biomedical engineering, chemical and process industry. In order to improve the performances of engineering facilities (e.g. hydraulic turbines) and to accelerate the development of techniques for medical treatment of serious diseases (e.g. tumors), it is essential to improve our understanding of cavitation and Multiphase Flow. For example, the present development towards the advanced hydrodynamic systems (e.g. space engine, propeller, hydraulic machinery system) often requires that the systems run under cavitating conditions and the risk of cavitation erosion needs to be controlled. The purpose of the ISCM 2014 was to discuss the state-of-the-art cavitation and multiphase flow research and their up-to-date applications, and to foster discussion and exchange of knowledge, and to provide an opportunity for the researchers, engineers and graduate students to report their latest outputs in these fields. Furthermore, the participants were also encouraged to present their work in progress with short lead time and discuss the encountered problems. ISCM 2014 covers all aspects of cavitation and Multiphase Flow, e.g. both fundamental and applied research with a focus on physical insights, numerical modelling and applications in engineering. Some specific topics are: Cavitating and Multiphase Flow in hydroturbines, pumps, propellers etc. Numerical simulation techniques Cavitation and multiphase flow erosion and anti-erosion techniques Measurement techniques for cavitation and

  5. Kaplan turbine tip vortex cavitation – analysis and prevention

    International Nuclear Information System (INIS)

    Motycak, L; Skotak, A; Kupcik, R

    2012-01-01

    The work is focused on one type of Kaplan turbine runner cavitation – a tip vortex cavitation. For detailed description of the tip vortex, the CFD analysis is used. On the basis of this analysis it is possible to estimate the intensity of cavitating vortex core, danger of possible blade surface and runner chamber cavitation pitting. In the paper, the ways how to avoid the pitting effect of the tip vortex are described. In order to prevent the blade surface against pitting, the following possibilities as the change of geometry of the runner blade, dimension of tip clearance and finally the installation of the anti-cavitation lips are discussed. The knowledge of the shape and intensity of the tip vortex helps to design the anti-cavitation lips more sophistically. After all, the results of the model tests of the Kaplan runner with or without anti-cavitation lips and the results of the CFD analysis are compared.

  6. Kaplan turbine tip vortex cavitation - analysis and prevention

    Science.gov (United States)

    Motycak, L.; Skotak, A.; Kupcik, R.

    2012-11-01

    The work is focused on one type of Kaplan turbine runner cavitation - a tip vortex cavitation. For detailed description of the tip vortex, the CFD analysis is used. On the basis of this analysis it is possible to estimate the intensity of cavitating vortex core, danger of possible blade surface and runner chamber cavitation pitting. In the paper, the ways how to avoid the pitting effect of the tip vortex are described. In order to prevent the blade surface against pitting, the following possibilities as the change of geometry of the runner blade, dimension of tip clearance and finally the installation of the anti-cavitation lips are discussed. The knowledge of the shape and intensity of the tip vortex helps to design the anti-cavitation lips more sophistically. After all, the results of the model tests of the Kaplan runner with or without anti-cavitation lips and the results of the CFD analysis are compared.

  7. Effects of cavitation on performance of automotive torque converter

    Directory of Open Access Journals (Sweden)

    Jaewon Ju

    2016-06-01

    Full Text Available Cavitation is a phenomenon whereby vapor bubbles of a flowing liquid are formed in a local region where the pressure of the liquid is below its vapor pressure. It is well known that cavitation in torque converters occurs frequently when a car with an automatic transmission makes an abrupt start. Cavitation is closely related to a performance drop and noise generation at a specific operating condition in a car and a torque converter itself. This study addressed the relation between cavitation and performance in an automotive torque converter in a quantitative and qualitative manner using numerical simulations. The cavitation was calculated at various operating conditions using a commercial flow solver with the homogeneous cavitation model, and the torque converter performance was compared with the experimental data. Numerical results well match to the data and indicate that the cavitation causes significant performance drop, as the pump speed increases or both speed ratio and reference pressure decrease.

  8. International Symposium of Cavitation and Multiphase Flow (ISCM 2014)

    International Nuclear Information System (INIS)

    Wu, Yulin

    2015-01-01

    The International Symposium on Cavitation and Multiphase Flow (ISCM 2014) was held in Beijing, China during 18th-21st October, 2014, which was jointly organized by Tsinghua University, Beijing, China and Jiangsu University, Zhenjiang, China. The co-organizer was the State Key Laboratory of Hydroscience and Engineering, Beijing, China. Cavitation and multiphase flow is one of paramount topics of fluid mechanics with many engineering applications covering a broad range of topics, e.g. hydraulic machinery, biomedical engineering, chemical and process industry. In order to improve the performances of engineering facilities (e.g. hydraulic turbines) and to accelerate the development of techniques for medical treatment of serious diseases (e.g. tumors), it is essential to improve our understanding of cavitation and Multiphase Flow. For example, the present development towards the advanced hydrodynamic systems (e.g. space engine, propeller, hydraulic machinery system) often requires that the systems run under cavitating conditions and the risk of cavitation erosion needs to be controlled. The purpose of the ISCM 2014 was to discuss the state-of-the-art cavitation and multiphase flow research and their up-to-date applications, and to foster discussion and exchange of knowledge, and to provide an opportunity for the researchers, engineers and graduate students to report their latest outputs in these fields. Furthermore, the participants were also encouraged to present their work in progress with short lead time and discuss the encountered problems. ISCM 2014 covers all aspects of cavitation and Multiphase Flow, e.g. both fundamental and applied research with a focus on physical insights, numerical modelling and applications in engineering. Some specific topics are: Cavitating and Multiphase Flow in hydroturbines, pumps, propellers etc. Numerical simulation techniques Cavitation and multiphase flow erosion and anti-erosion techniques Measurement techniques for cavitation and

  9. Laser-nucleated acoustic cavitation in focused ultrasound.

    Science.gov (United States)

    Gerold, Bjoern; Kotopoulis, Spiros; McDougall, Craig; McGloin, David; Postema, Michiel; Prentice, Paul

    2011-04-01

    Acoustic cavitation can occur in therapeutic applications of high-amplitude focused ultrasound. Studying acoustic cavitation has been challenging, because the onset of nucleation is unpredictable. We hypothesized that acoustic cavitation can be forced to occur at a specific location using a laser to nucleate a microcavity in a pre-established ultrasound field. In this paper we describe a scientific instrument that is dedicated to this outcome, combining a focused ultrasound transducer with a pulsed laser. We present high-speed photographic observations of laser-induced cavitation and laser-nucleated acoustic cavitation, at frame rates of 0.5×10(6) frames per second, from laser pulses of energy above and below the optical breakdown threshold, respectively. Acoustic recordings demonstrated inertial cavitation can be controllably introduced to the ultrasound focus. This technique will contribute to the understanding of cavitation evolution in focused ultrasound including for potential therapeutic applications. © 2011 American Institute of Physics

  10. Prevention of Pressure Oscillations in Modeling a Cavitating Acoustic Fluid

    Directory of Open Access Journals (Sweden)

    B. Klenow

    2010-01-01

    Full Text Available Cavitation effects play an important role in the UNDEX loading of a structure. For far-field UNDEX, the structural loading is affected by the formation of local and bulk cavitation regions, and the pressure pulses resulting from the closure of the cavitation regions. A common approach to numerically modeling cavitation in far-field underwater explosions is Cavitating Acoustic Finite Elements (CAFE and more recently Cavitating Acoustic Spectral Elements (CASE. Treatment of cavitation in this manner causes spurious pressure oscillations which must be treated by a numerical damping scheme. The focus of this paper is to investigate the severity of these oscillations on the structural response and a possible improvement to CAFE, based on the original Boris and Book Flux-Corrected Transport algorithm on structured meshes [6], to limit oscillations without the energy loss associated with the current damping schemes.

  11. Influence of cavitation bubble growth by rectified diffusion on cavitation-enhanced HIFU

    Science.gov (United States)

    Okita, Kohei; Sugiyama, Kazuyasu; Takagi, Shu; Matsumoto, Yoichiro

    2017-11-01

    Cavitation is becoming increasingly important in therapeutic ultrasound applications such as diagnostic, tumor ablation and lithotripsy. Mass transfer through gas-liquid interface due to rectified diffusion is important role in an initial stage of cavitation bubble growth. In the present study, influences of the rectified diffusion on cavitation-enhanced high-intensity focused ultrasound (HIFU) was investigated numerically. Firstly, the mass transfer rate of gas from the surrounding medium to the bubble was examined as function of the initial bubble radius and the driving pressure amplitude. As the result, the pressure required to bubble growth was decreases with increasing the initial bubble radius. Next, the cavitation-enhanced HIFU, which generates cavitation bubbles by high-intensity burst and induces the localized heating owing to cavitation bubble oscillation by low-intensity continuous waves, was reproduced by the present simulation. The heating region obtained by the simulation is agree to the treatment region of an in vitro experiment. Additionally, the simulation result shows that the localized heating is enhanced by the increase of the equilibrium bubble size due to the rectified diffusion. This work was supported by JSPS KAKENHI Grant Numbers JP26420125,JP17K06170.

  12. Comparative reading support system for lung cancer CT screening

    International Nuclear Information System (INIS)

    Kubo, Mitsuru; Saita, Shinsuke; Kawata, Yoshiki; Niki, Noboru; Suzuki, Hidenobu; Ohmatsu, Hironobu; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki

    2010-01-01

    The comparative reading is performed using current and past images of the same case obtained from lung cancer CT screening. The result of this is useful for the early detection of lung cancer. Our paper describes the efficiency improvement of comparative reading using 10 mm slice thickness CT images by developing the system consists of slice registration method, pulmonary nodule registration method, and quantitative evaluation method of pulmonary nodule's degree of change. The proposed system is applied to CT images scanned for 1107 times of 85 cases with 198 pulmonary nodules and is evaluated by comparing it with the reading result of the doctors. We show the effectiveness of the system. (author)

  13. The making of a cavitation children's book

    Science.gov (United States)

    Henry de Frahan, Marc; Patterson, Brandon; Lazar, Erika

    2016-11-01

    Engaging young children in science is particularly important to future scientific endeavors. From thunderstorms to the waterpark, children are constantly exposed to the wonders of fluid dynamics. Among fluid phenomena, bubbles have always fascinated children. Yet some of the most exciting aspects of bubbles, such as cavitation, are scarcely known to non-experts. To introduce cavitation to a five year old audience, we wrote "Brooke Bubble Breaks Things", a children's book about the adventures of a cavitation bubble learning about all the things she could break. In this talk, we discuss how a children's book is made by walking through the steps involved in creating the book from concept to publication. We focus on strategies for successfully communicating a technical message while balancing entertainment and fidelity to nature. To provide parents, teachers, and young inquiring minds with a detailed explanation of the physics and applications of cavitation, we also created a website with detailed explanations, animations, and links to further information. We aim to convince the fluids community that writing picture books is an intellectually stimulating and fun way of communicating fluids principles and applications to children. ArtsEngine Microgrant at the University of Michigan.