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Sample records for cavitating lung nodule

  1. Lung Nodules: Overview

    Science.gov (United States)

    ... Research & Science Education & Training Home Conditions Lung Nodules Lung Nodules Make an Appointment Find a Doctor Ask ... Kern, MD (June 01, 2016) What is a lung nodule? A lung nodule is also called a ...

  2. Multiple Cavitating Nodules in a Renal Transplant Recipient

    Directory of Open Access Journals (Sweden)

    Sharla-Rae J Olsen

    2009-01-01

    Full Text Available Pulmonary nodules are common following solid organ transplantation and vary in etiology. Nodules with central cavitation are most likely to be of infectious origin in the post-transplant population. A novel presentation of post-transplant lymphoproliferative disorder manifesting as multiple cavitating pulmonary nodules is described. The patient, a 45-year-old female renal transplant recipient, presented with constitutional symptoms and a chest x-ray showing multiple bilateral cavitating lesions. A computed tomography scan confirmed innumerable, randomly dispersed, cavitating nodules in the lung parenchyma. Multiple large hypodense lesions were identified in the liver and spleen. The appearance of the native and transplanted kidneys was normal. A liver biopsy identified an Epstein-Barr virus-negative, diffuse, large B cell lymphoma. Repeat imaging after treatment with a cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone/prednisolone regimen demonstrated dramatic resolution of all lesions. The present case represents a unique radiographic presentation of post-transplant lymphoproliferative disorder not previously reported in the literature.

  3. Automatic lung nodule classification with radiomics approach

    Science.gov (United States)

    Ma, Jingchen; Wang, Qian; Ren, Yacheng; Hu, Haibo; Zhao, Jun

    2016-03-01

    Lung cancer is the first killer among the cancer deaths. Malignant lung nodules have extremely high mortality while some of the benign nodules don't need any treatment .Thus, the accuracy of diagnosis between benign or malignant nodules diagnosis is necessary. Notably, although currently additional invasive biopsy or second CT scan in 3 months later may help radiologists to make judgments, easier diagnosis approaches are imminently needed. In this paper, we propose a novel CAD method to distinguish the benign and malignant lung cancer from CT images directly, which can not only improve the efficiency of rumor diagnosis but also greatly decrease the pain and risk of patients in biopsy collecting process. Briefly, according to the state-of-the-art radiomics approach, 583 features were used at the first step for measurement of nodules' intensity, shape, heterogeneity and information in multi-frequencies. Further, with Random Forest method, we distinguish the benign nodules from malignant nodules by analyzing all these features. Notably, our proposed scheme was tested on all 79 CT scans with diagnosis data available in The Cancer Imaging Archive (TCIA) which contain 127 nodules and each nodule is annotated by at least one of four radiologists participating in the project. Satisfactorily, this method achieved 82.7% accuracy in classification of malignant primary lung nodules and benign nodules. We believe it would bring much value for routine lung cancer diagnosis in CT imaging and provide improvement in decision-support with much lower cost.

  4. False positive reduction for lung nodule CAD

    Science.gov (United States)

    Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.

    2007-03-01

    Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.

  5. The Lung TIME: annotated lung nodule dataset and nodule detection framework

    Science.gov (United States)

    Dolejsi, Martin; Kybic, Jan; Polovincak, Michal; Tuma, Stanislav

    2009-02-01

    The Lung Test Images from Motol Environment (Lung TIME) is a new publicly available dataset of thoracic CT scans with manually annotated pulmonary nodules. It is larger than other publicly available datasets. Pulmonary nodules are lesions in the lungs, which may indicate lung cancer. Their early detection significantly improves survival rate of patients. Automatic nodule detecting systems using CT scans are being developed to reduce physicians' load and to improve detection quality. Besides presenting our own nodule detection system, in this article, we mainly address the problem of testing and comparison of automatic nodule detection methods. Our publicly available 157 CT scan dataset with 394 annotated nodules contains almost every nodule types (pleura attached, vessel attached, solitary, regular, irregular) with 2-10mm in diameter, except ground glass opacities (GGO). Annotation was done consensually by two experienced radiologists. The data are in DICOM format, annotations are provided in XML format compatible with the Lung Imaging Database Consortium (LIDC). Our computer aided diagnosis system (CAD) is based on mathematical morphology and filtration with a subsequent classification step. We use Asymmetric AdaBoost classifier. The system was tested using TIME, LIDC and ANODE09 databases. The performance was evaluated by cross-validation for Lung TIME and LIDC, and using the supplied evaluation procedure for ANODE09. The sensitivity at chosen working point was 94.27% with 7.57 false positives/slice for TIME and LIDC datasets combined, 94.03% with 5.46 FPs/slice for the Lung TIME, 89.62% sensitivity with 12.03 FPs/slice for LIDC, and 78.68% with 4,61 FPs/slice when applied on ANODE09.

  6. LUNGx Challenge for computerized lung nodule classification.

    Science.gov (United States)

    Armato, Samuel G; Drukker, Karen; Li, Feng; Hadjiiski, Lubomir; Tourassi, Georgia D; Engelmann, Roger M; Giger, Maryellen L; Redmond, George; Farahani, Keyvan; Kirby, Justin S; Clarke, Laurence P

    2016-10-01

    The purpose of this work is to describe the LUNGx Challenge for the computerized classification of lung nodules on diagnostic computed tomography (CT) scans as benign or malignant and report the performance of participants' computerized methods along with that of six radiologists who participated in an observer study performing the same Challenge task on the same dataset. The Challenge provided sets of calibration and testing scans, established a performance assessment process, and created an infrastructure for case dissemination and result submission. Ten groups applied their own methods to 73 lung nodules (37 benign and 36 malignant) that were selected to achieve approximate size matching between the two cohorts. Area under the receiver operating characteristic curve (AUC) values for these methods ranged from 0.50 to 0.68; only three methods performed statistically better than random guessing. The radiologists' AUC values ranged from 0.70 to 0.85; three radiologists performed statistically better than the best-performing computer method. The LUNGx Challenge compared the performance of computerized methods in the task of differentiating benign from malignant lung nodules on CT scans, placed in the context of the performance of radiologists on the same task. The continued public availability of the Challenge cases will provide a valuable resource for the medical imaging research community.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. [Lung cancer screening and management of small pulmonary nodules].

    Science.gov (United States)

    Schulz, Christian

    2015-03-01

    Worldwide lung cancer is the leading cause of death from cancer. Most lung cancers are diagnosed at an advanced stage, so survival after lung cancer is generally poor. Diagnosis of lung cancer at earlier stages may be associated with an increased survival rate. This indicates that the implementation of lung cancer screening programs at the population level by means of low dose computed tomography might helpful to improve the outcome and mortality of lung cancer patients. By means of rapid advances in imaging technologies over the last decades it became possible to detect small lung nodules as small as a couple of millimeters. This recent developments require management algorithms to guide the clinical management of suspicious and indeterminate lung nodules found in computer tomography during lung cancer screening or by incidental finding.This review will focus on both, the recent advances in lung cancer screening and the guidelines for the management of small pulmonary nodules.

  9. Probable Phaeoacremonium parasiticum as a cause of cavitary native lung nodules after single lung transplantation.

    Science.gov (United States)

    Shah, S K; Parto, P; Lombard, G A; James, M A; Beckles, D L; Lick, S; Valentine, V G

    2013-02-01

    Lung nodules after lung transplantation most often represent infection or post-transplant lymphoproliferative disorder in the allograft. Conversely, native lung nodules in single lung transplant recipients are more likely to be bronchogenic carcinoma. We present a patient who developed native lung cavitary nodules. Although malignancy was anticipated, evaluation revealed probable Phaeoacremonium parasiticum infection. Phaeoacremonium parasiticum is a dematiaceous fungus first described as a cause of soft tissue infection in a renal transplant patient. Lung nodules have not been previously described and this is the first case, to our knowledge, of P. parasiticum identified after lung transplantation. © 2012 John Wiley & Sons A/S.

  10. Quantitative analysis of CT attenuation distribution patterns of nodule components for pathologic categorization of lung nodules

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    Zhou, Chuan; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir M.; Chughtai, Aamer; Kazerooni, Ella A.

    2017-03-01

    We investigated the feasibility of classifying pathologic invasive nodules and pre-invasive or benign nodules by quantitative analysis of the CT attenuation distribution patterns and other radiomic features of lung nodule components. We developed a new 3D adaptive multi-component Expectation-Maximization (EM) analysis method to segment the solid and non-solid nodule components and the surrounding lung parenchymal region. Features were extracted to characterize the size, shape, and the CT attenuation distribution of the entire nodule as well as the individual regions. With permission of the National Lung Screening Trial (NLST) project, a data set containing the baseline low dose CT scans of 53 cases with known pathologic tumor type categorization was obtained. The 53 cases contain 45 invasive nodules (group 1) and 42 pre-invasive nodules (group 2). A logistic regression model (LRM) was built using leave-one-case-out resampling and receiver operating characteristic (ROC) analysis for classification of group 1 and group 2, using the pathologic categorization as ground truth. With 4 selected features, the LRM achieved a test area under the curve (AUC) value of 0.877+/-0.036. The results demonstrated that the pathologic invasiveness of lung adenocarcinomas could be categorized according to the CT attenuation distribution patterns of the nodule components manifested on LDCT images.

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

    NARCIS (Netherlands)

    Ashraf, H.; Hoop, B. 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

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

    NARCIS (Netherlands)

    Ashraf, H.; Hoop, B. 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

  13. GA-SVM Based Lungs Nodule Detection and Classification

    Science.gov (United States)

    Jaffar, M. Arfan; Hussain, Ayyaz; Jabeen, Fauzia; Nazir, M.; Mirza, Anwar M.

    In this paper we have proposed a method for lungs nodule detection from computed tomography (CT) scanned images by using Genetic Algorithms (GA) and morphological techniques. First of all, GA has been used for automated segmentation of lungs. Region of interests (ROIs) have been extracted by using 8 directional searches slice by slice and then features extraction have been performed. Finally SVM have been used to classify ROI that contain nodule. The proposed system is capable to perform fully automatic segmentation and nodule detection from CT Scan Lungs images. The technique was tested against the 50 datasets of different patients received from Aga Khan Medical University, Pakistan and Lung Image Database Consortium (LIDC) dataset.

  14. Probabilistic lung nodule classification with belief decision trees.

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    Zinovev, Dmitriy; Feigenbaum, Jonathan; Furst, Jacob; Raicu, Daniela

    2011-01-01

    In reading Computed Tomography (CT) scans with potentially malignant lung nodules, radiologists make use of high level information (semantic characteristics) in their analysis. Computer-Aided Diagnostic Characterization (CADc) systems can assist radiologists by offering a "second opinion"--predicting these semantic characteristics for lung nodules. In this work, we propose a way of predicting the distribution of radiologists' opinions using a multiple-label classification algorithm based on belief decision trees using the National Cancer Institute (NCI) Lung Image Database Consortium (LIDC) dataset, which includes semantic annotations by up to four human radiologists for each one of the 914 nodules. Furthermore, we evaluate our multiple-label results using a novel distance-threshold curve technique--and, measuring the area under this curve, obtain 69% performance on the validation subset. We conclude that multiple-label classification algorithms are an appropriate method of representing the diagnoses of multiple radiologists on lung CT scans when ground truth is unavailable.

  15. 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.

  16. Hybrid detection of lung nodules on CT scan images

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Lin; Tan, Yongqiang; Schwartz, Lawrence H.; Zhao, Binsheng, E-mail: bz2166@columbia.edu [Department of Radiology, Columbia University Medical Center, 630 West 168th Street, New York, New York 10032 (United States)

    2015-09-15

    Purpose: The diversity of lung nodules poses difficulty for the current computer-aided diagnostic (CAD) schemes for lung nodule detection on computed tomography (CT) scan images, especially in large-scale CT screening studies. We proposed a novel CAD scheme based on a hybrid method to address the challenges of detection in diverse lung nodules. Methods: The hybrid method proposed in this paper integrates several existing and widely used algorithms in the field of nodule detection, including morphological operation, dot-enhancement based on Hessian matrix, fuzzy connectedness segmentation, local density maximum algorithm, geodesic distance map, and regression tree classification. All of the adopted algorithms were organized into tree structures with multi-nodes. Each node in the tree structure aimed to deal with one type of lung nodule. Results: The method has been evaluated on 294 CT scans from the Lung Image Database Consortium (LIDC) dataset. The CT scans were randomly divided into two independent subsets: a training set (196 scans) and a test set (98 scans). In total, the 294 CT scans contained 631 lung nodules, which were annotated by at least two radiologists participating in the LIDC project. The sensitivity and false positive per scan for the training set were 87% and 2.61%. The sensitivity and false positive per scan for the testing set were 85.2% and 3.13%. Conclusions: The proposed hybrid method yielded high performance on the evaluation dataset and exhibits advantages over existing CAD schemes. We believe that the present method would be useful for a wide variety of CT imaging protocols used in both routine diagnosis and screening studies.

  17. 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....

  18. Automated segmentation refinement of small lung nodules in CT scans by local shape analysis.

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    Diciotti, Stefano; Lombardo, Simone; Falchini, Massimo; Picozzi, Giulia; Mascalchi, Mario

    2011-12-01

    One of the most important problems in the segmentation of lung nodules in CT imaging arises from possible attachments occurring between nodules and other lung structures, such as vessels or pleura. In this report, we address the problem of vessels attachments by proposing an automated correction method applied to an initial rough segmentation of the lung nodule. The method is based on a local shape analysis of the initial segmentation making use of 3-D geodesic distance map representations. The correction method has the advantage that it locally refines the nodule segmentation along recognized vessel attachments only, without modifying the nodule boundary elsewhere. The method was tested using a simple initial rough segmentation, obtained by a fixed image thresholding. The validation of the complete segmentation algorithm was carried out on small lung nodules, identified in the ITALUNG screening trial and on small nodules of the lung image database consortium (LIDC) dataset. In fully automated mode, 217/256 (84.8%) lung nodules of ITALUNG and 139/157 (88.5%) individual marks of lung nodules of LIDC were correctly outlined and an excellent reproducibility was also observed. By using an additional interactive mode, based on a controlled manual interaction, 233/256 (91.0%) lung nodules of ITALUNG and 144/157 (91.7%) individual marks of lung nodules of LIDC were overall correctly segmented. The proposed correction method could also be usefully applied to any existent nodule segmentation algorithm for improving the segmentation quality of juxta-vascular nodules.

  19. Benign-Malignant Lung Nodule Classification with Geometric and Appearance Histogram Features

    OpenAIRE

    Shewaye, Tizita Nesibu; Mekonnen, Alhayat Ali

    2016-01-01

    Lung cancer accounts for the highest number of cancer deaths globally. Early diagnosis of lung nodules is very important to reduce the mortality rate of patients by improving the diagnosis and treatment of lung cancer. This work proposes an automated system to classify lung nodules as malignant and benign in CT images. It presents extensive experimental results using a combination of geometric and histogram lung nodule image features and different linear and non-linear discriminant classifier...

  20. Potential Lung Nodules Identification for Characterization by Variable Multistep Threshold and Shape Indices from CT Images

    Directory of Open Access Journals (Sweden)

    Saleem Iqbal

    2014-01-01

    Full Text Available Computed tomography (CT is an important imaging modality. Physicians, surgeons, and oncologists prefer CT scan for diagnosis of lung cancer. However, some nodules are missed in CT scan. Computer aided diagnosis methods are useful for radiologists for detection of these nodules and early diagnosis of lung cancer. Early detection of malignant nodule is helpful for treatment. Computer aided diagnosis of lung cancer involves lung segmentation, potential nodules identification, features extraction from the potential nodules, and classification of the nodules. In this paper, we are presenting an automatic method for detection and segmentation of lung nodules from CT scan for subsequent features extraction and classification. Contribution of the work is the detection and segmentation of small sized nodules, low and high contrast nodules, nodules attached with vasculature, nodules attached to pleura membrane, and nodules in close vicinity of the diaphragm and lung wall in one-go. The particular techniques of the method are multistep threshold for the nodule detection and shape index threshold for false positive reduction. We used 60 CT scans of “Lung Image Database Consortium-Image Database Resource Initiative” taken by GE medical systems LightSpeed16 scanner as dataset and correctly detected 92% nodules. The results are reproducible.

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

    OpenAIRE

    Mehdi Alilou; Vassili Kovalev; Eduard Snezhko; Vahid Taimouri

    2014-01-01

    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 wit...

  2. Outcomes of lung cancers manifesting as nonsolid nodules.

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    Yip, Rowena; Wolf, Andrea; Tam, Kathleen; Taioli, Emanuela; Olkin, Ingram; Flores, Raja M; Yankelevitz, David F; Henschke, Claudia I

    2016-07-01

    This is a comprehensive review and re-analysis of available literature to assess the outcome of lung cancer presenting as nonsolid nodules (NSNs), a more indolent form of cancer. PubMed and EMBASE were searched for articles reporting on CT-detected lung cancers manifesting as NSNs published in English on or before July 17, 2015. Only studies including clinicopathologic data, lung cancer-specific survival, or overall survival were included. Data extraction was performed by three independent reviewers using prespecified criteria. Twenty-four articles from 5 countries met criteria and they included 704 subjects with 712 lung cancers manifesting as NSNs. Each article reported from 2 to 100 lung cancer cases with a median follow up of 18-51 months. All NSNs were Stage I adenocarcinoma without pathologic nodal involvement upon resection, except for one case in which the NSN progressed to become part-solid nodule after 6 years of follow-up. The five-year lung cancer-specific survival rate was 100%. These findings suggest an indolent course for lung cancers manifesting as NSNs.

  3. 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...... correct diagnosis and optimal management. Here we present the latest advances in the radiologic imaging and pathology of GGO nodules, demonstrating that radiologic features are increasingly predictive of the pathology of GGO nodules. We review the current guidelines from the Fleischner Society......, 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...

  4. The characteristic scale as a consistent indicator of lung nodule size in CT imaging

    OpenAIRE

    Diciotti, Stefano; Lombardo, Simone; Coppini, Giuseppe; Grassi, L.; Petrolo, L; G.Picozzi; Falchini, Massimo; Mascalchi, Mario

    2008-01-01

    Nodule growth as observed in CT scans is the primary malignancy clue of indeterminate small lung nodules. A new approach to assess the 3D size of lung nodules which is based on LoG scale space theory is described. Validation using private (ITALUNG) and public (LIDC) data-set are described.

  5. A Solitary Feature-based Lung Nodule Detection Approach for Chest X-Ray Radiographs.

    Science.gov (United States)

    Li, Xuechen; Shen, Linlin; Luo, Suhuai

    2017-01-31

    Lung cancer is one of the most deadly diseases. It has a high death rate and its incidence rate has been increasing all over the world. Lung cancer appears as a solitary nodule in chest x-ray radiograph (CXR). Therefore, lung nodule detection in CXR could have a significant impact on early detection of lung cancer. Radiologists define a lung nodule in chest x-ray radiographs as "solitary white nodule-like blob". However, the solitary feature has not been employed for lung nodule detection before. In this paper, a solitary feature-based lung nodule detection method was proposed. We employed stationary wavelet transform and convergence index filter to extract the texture features and used AdaBoost to generate white nodule-likeness map. A solitary feature was defined to evaluate the isolation degree of candidates. Both the isolation degree and the white nodule-likeness were used as final evaluation of lung nodule candidates. The proposed method shows better performance and robustness than those reported in previous research. More than 80% and 93% of lung nodules in the lung field in the JSRT database were detected when the false positives per image was two and five, respectively. The proposed approach has the potential of being used in clinical practice.

  6. Cavitating Lung Lesions in Chronic Thromboembolic Pulmonary Hypertension

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    edwin j r van beek

    2008-09-01

    Full Text Available Purpose: The aim of this study is to assess the incidence and natural history of cavitating lung lesions in chronic thromboembolic pulmonary hypertension (CTEPH, note thrombus position between patients with and without a cavity and determine whether their development is a predictor of mortality. Materials & Methods: All patients with confirmed CTEPH attending our Pulmonary Vascular Unit between February 1998 and January 2006 were identified, and a review of their notes and imaging was performed. Thrombus position, pre-disposing factors, cavity progression and mortality were noted, and comparisons made between those with and without a cavity. Results: 11 of 104 patients had a cavity (10.6%. Thrombus distribution was similar between those with and those without a cavity. Preceding infection was not proven in  most cases. 27.3% of patients with a cavity died compared to 26.8% of those without. Conclusion: Cavity formation in CTEPH is 3 times more common than in acute pulmonary embolism. Thrombus position does not predict cavity development, and the presence of a cavity may serve as an indicator of disease severity but does not appear to predict mortality.

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

    DEFF Research Database (Denmark)

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

    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......, 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...... 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...

  8. Contextual convolutional neural networks for lung nodule classification using Gaussian-weighted average image patches

    Science.gov (United States)

    Lee, Haeil; Lee, Hansang; Park, Minseok; Kim, Junmo

    2017-03-01

    Lung cancer is the most common cause of cancer-related death. To diagnose lung cancers in early stages, numerous studies and approaches have been developed for cancer screening with computed tomography (CT) imaging. In recent years, convolutional neural networks (CNN) have become one of the most common and reliable techniques in computer aided detection (CADe) and diagnosis (CADx) by achieving state-of-the-art-level performances for various tasks. In this study, we propose a CNN classification system for false positive reduction of initially detected lung nodule candidates. First, image patches of lung nodule candidates are extracted from CT scans to train a CNN classifier. To reflect the volumetric contextual information of lung nodules to 2D image patch, we propose a weighted average image patch (WAIP) generation by averaging multiple slice images of lung nodule candidates. Moreover, to emphasize central slices of lung nodules, slice images are locally weighted according to Gaussian distribution and averaged to generate the 2D WAIP. With these extracted patches, 2D CNN is trained to achieve the classification of WAIPs of lung nodule candidates into positive and negative labels. We used LUNA 2016 public challenge database to validate the performance of our approach for false positive reduction in lung CT nodule classification. Experiments show our approach improves the classification accuracy of lung nodules compared to the baseline 2D CNN with patches from single slice image.

  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. The calcified lung nodule: What does it mean?

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    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.

  11. Usage of Template Matching for Lung Nodule Detection in CT Images

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    Farzaneh Shayegh

    2008-09-01

    Full Text Available In this paper we describe the lung nodule detection through image processing methods. Therefore, in the preprocessing stage, we use a medical-like method to omit all objects that surely they are not nodule. In this way nodule candidates are obtained. Therefore, false positives decay, while rate of main process does not increase. Finally, nodule candidates are selected through these suspicious regions. In the first step, we extracted candidate areas of the lung using synchronous thresholding in consecutive slices, medical decision implementation and also morphology methods. We divided the preprocessing stage into two phases for detecting all of lung nodules more accurately, depend on the nodule is connected to lung wall or vessel or it is an alone nodule.Here, template matching and maximum similarity method have used for nodule detection. The used database comes from LIDC database images that consist of 7 patients' CT scans. All of nodules are completely detected and there are 3 FP/slice. Value of similarity has been computed for all of points (pixels that determined in preprocessing stage. Indeed, the limited search area makes the optimum (i.e. direct search algorithm as fast as other sub-optimal search methods. Indeed, this method is faster than other methods that don’t have enough attention to information of CT scan slices.

  12. [Sclerosing hemangioma presenting as a solitary lung nodule. Report of one case].

    Science.gov (United States)

    Cardemil, Gonzalo; Fernández, Eduardo; Riffo, Paola; Reyes, Diego; Ledezma, Rodrigo; Mira, Magdalena; Morales, Claudia; Salguero, Jorge

    2004-07-01

    Lung sclerosing hemangioma is an uncommon tumor that presents as a solitary asymptomatic nodule and that affects middle age women. It derives from type II pneumocytes. We report a 52 years old female with a solitary lung nodule detected in a chest X ray requested for the diagnosis of an acute respiratory disease. The nodule was excised by video thoracoscopy and the frozen section biopsy was informed as a non small cell undifferentiated carcinoma. Therefore an inferior right lobectomy with lymph node resection was performed. The definitive biopsy was informed as a lung sclerosing hemangioma.

  13. A novel approach to CAD system for the detection of lung nodules in CT images.

    Science.gov (United States)

    Javaid, Muzzamil; Javid, Moazzam; Rehman, Muhammad Zia Ur; Shah, Syed Irtiza Ali

    2016-10-01

    Detection of pulmonary nodule plays a significant role in the diagnosis of lung cancer in early stage that improves the chances of survival of an individual. In this paper, a computer aided nodule detection method is proposed for the segmentation and detection of challenging nodules like juxtavascular and juxtapleural nodules. Lungs are segmented from computed tomography (CT) images using intensity thresholding; brief analysis of CT image histogram is done to select a suitable threshold value for better segmentation results. Simple morphological closing is used to include juxtapleural nodules in segmented lung regions. K-means clustering is applied for the initial detection and segmentation of potential nodules; shape specific morphological opening is implemented to refine segmentation outcomes. These segmented potential nodules are then divided into six groups on the basis of their thickness and percentage connectivity with lung walls. Grouping not only helped in improving system's efficiency but also reduced computational time, otherwise consumed in calculating and analyzing unnecessary features for all nodules. Different sets of 2D and 3D features are extracted from nodules in each group to eliminate false positives. Small size nodules are differentiated from false positives (FPs) on the basis of their salient features; sensitivity of the system for small nodules is 83.33%. SVM classifier is used for the classification of large nodules, for which the sensitivity of the proposed system is 93.8% applying 10-fold cross-validation. Receiver Operating Characteristic (ROC) curve is used for the analysis of CAD system. Overall sensitivity of the system is 91.65% with 3.19 FPs per case, and accuracy is 96.22%. The system took 3.8 seconds to analyze each image.

  14. 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.)

  15. 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.

  16. 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.

  17. 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.

  18. Lung nodule detection using 3D convolutional neural networks trained on weakly labeled data

    Science.gov (United States)

    Anirudh, Rushil; Thiagarajan, Jayaraman J.; Bremer, Timo; Kim, Hyojin

    2016-03-01

    Early detection of lung nodules is currently the one of the most effective ways to predict and treat lung cancer. As a result, the past decade has seen a lot of focus on computer aided diagnosis (CAD) of lung nodules, whose goal is to efficiently detect, segment lung nodules and classify them as being benign or malignant. Effective detection of such nodules remains a challenge due to their arbitrariness in shape, size and texture. In this paper, we propose to employ 3D convolutional neural networks (CNN) to learn highly discriminative features for nodule detection in lieu of hand-engineered ones such as geometric shape or texture. While 3D CNNs are promising tools to model the spatio-temporal statistics of data, they are limited by their need for detailed 3D labels, which can be prohibitively expensive when compared obtaining 2D labels. Existing CAD methods rely on obtaining detailed labels for lung nodules, to train models, which is also unrealistic and time consuming. To alleviate this challenge, we propose a solution wherein the expert needs to provide only a point label, i.e., the central pixel of of the nodule, and its largest expected size. We use unsupervised segmentation to grow out a 3D region, which is used to train the CNN. Using experiments on the SPIE-LUNGx dataset, we show that the network trained using these weak labels can produce reasonably low false positive rates with a high sensitivity, even in the absence of accurate 3D labels.

  19. Impact of image quality, radiologists, lung segments, and Gunnar eyewear on detectability of lung nodules in chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Christe, Andreas [Dept. of Radiology, Stanford Univ. Medical Center, Stanford (United States); Dept. of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Univ. Hospital, Univ. of Bern, Bern (Switzerland)], e-mail: andreas.christe@insel.ch; Ebner, Lukas; Steiger, Philipp; Vock, Peter [Dept. of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Univ. Hospital, Univ. of Bern, Bern (Switzerland); Parikh, Sachin R. [Dept. of Radiology, Emory Univ. School of Medicine, Atlanta (United States); Shah, Akash D. [Proscan Imaging, Cincinnati (United States); Roychoudhury, Kingshuk [Statistics Dept., Univ. Coll. Cork, Cork (Ireland); Roos, Justus E. [Dept. of Radiology, Stanford Univ. Medical Center, Stanford (United States)

    2013-07-15

    Background: Despite the increasingly higher spatial and contrast resolution of CT, nodular lesions are prone to be missed on chest CT. Tinted lenses increase visual acuity and contrast sensitivity by filtering short wavelength light of solar and artificial origin. Purpose: To test the impact of Gunnar eyewear, image quality (standard versus low dose CT) and nodule location on detectability of lung nodules in CT and to compare their individual influence. Material and Methods: A pre-existing database of CT images of patients with lung nodules >5 mm, scanned with standard does image quality (150 ref mAs/120 kVp) and lower dose/quality (40 ref mAs/120 kVp), was used. Five radiologists read 60 chest CTs twice: once with Gunnar glasses and once without glasses with a 1 month break between. At both read-outs the cases were shown at lower dose or standard dose level to quantify the influence of both variables (eyewear vs. image quality) on nodule sensitivity. Results: The sensitivity of CT for lung nodules increased significantly using Gunnar eyewear for two readers and insignificantly for two other readers. Over all, the mean sensitivity of all radiologist raised significantly from 50% to 53%, using the glasses (P value = 0.034). In contrast, sensitivity for lung nodules was not significantly affected by lowering the image quality from 150 to 40 ref mAs. The average sensitivity was 52% at low dose level, that was even 0.7 % higher than at standard dose level (P value = 0.40). The strongest impact on sensitivity had the factors readers and nodule location (lung segments). Conclusion: Sensitivity for lung nodules was significantly enhanced by Gunnar eyewear (+3 %), while lower image quality (40 ref mAs) had no impact on nodule sensitivity. Not using the glasses had a bigger impact on sensitivity than lowering the image quality.

  20. 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; Th. Scholten, Ernst; Schaefer-Prokop, Cornelia; Wille, Mathilde M. W.; Marchianò, Alfonso; Pastorino, Ugo; Prokop, Mathias; van Ginneken, Bram

    2017-04-01

    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 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.

  1. Evaluation of a New Ultrasound Thoracoscope for Localization of Lung Nodules in Ex Vivo Human Lungs.

    Science.gov (United States)

    Ujiie, Hideki; Kato, Tatsuya; Hu, Hsin-Pei; Hasan, Suhaib; Patel, Priya; Wada, Hironobu; Lee, Daiyoon; Fujino, Kosuke; Hwang, David M; Cypel, Marcelo; de Perrot, Marc; Pierre, Andrew; Darling, Gail; Waddell, Thomas K; Keshavjee, Shaf; Yasufuku, Kazuhiro

    2017-03-01

    Localization of small, nonvisible and nonpalpable nodules is challenging during video-assisted thoracoscopic surgery. We evaluated the feasibility of using a new ultrasound thoracoscope to localize nodules in resected ex vivo human lungs. The tumor was localized and measured in its greatest dimension with a prototype ultrasound thoracoscope (XLTF-UC180; Olympus Corporation, Tokyo, Japan) at different frequencies (5.0 to 12.0 MHz) and different lung specimen states (deflated, semiinflated). Measured tumor size and depth from lung surface were compared and correlated to the true diameter and depth from lung surface acquired from pathologic morphology. Ex vivo evaluation was performed on 16 solid nodules and nine part solid ground-glass nodules. All tumors were successfully localized in the deflated lung specimens (average size, 13.7 ± 5.2 mm). The tumor boundaries were best evaluated with an ultrasound frequency of 10 MHz. Solid nodules were more easily visualized than ground-glass nodules. Part solid ground-glass nodules were not easily detected in the semiinflated specimen owing to peritumoral air surrounding the tumor. Tumor boundaries were also difficult to identify in deeply situated tumors and in lungs with underlying disease. A strong positive correlation existed between the ultrasound measurement and true measurement of tumor size (R(2) = 0.89, p lungs. The clarity of the tumor boundaries is influenced by the tumor type and depth and the underlying pulmonary disease. Complete lung deflation and the use of 10 MHz ultrasound frequency optimize the visualization of target tumors. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  2. 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.

  3. Management of subsolid pulmonary nodules in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Oudkerk, Matthijs

    2015-01-01

    The distinct appearance and behavior of subsolid pulmonary nodules (SSNs) has resulted in separate recommendations for the management of solitary SSNs, both for incidentally detected as well as for screen detected nodules. However, these guidelines have been based primarily on expert opinion. Recent

  4. Management of subsolid pulmonary nodules in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Oudkerk, Matthijs

    The distinct appearance and behavior of subsolid pulmonary nodules (SSNs) has resulted in separate recommendations for the management of solitary SSNs, both for incidentally detected as well as for screen detected nodules. However, these guidelines have been based primarily on expert opinion.

  5. Small pulmonary nodules in baseline and incidence screening rounds of low-dose CT lung cancer screening.

    Science.gov (United States)

    Walter, Joan E; Heuvelmans, Marjolein A; Oudkerk, Matthijs

    2017-02-01

    Currently, lung cancer screening by low-dose computed tomography (LDCT) is widely recommended for high-risk individuals by US guidelines, but there still is an ongoing debate concerning respective recommendations for European countries. Nevertheless, the available data regarding pulmonary nodules released by lung cancer screening studies could improve future screening guidelines, as well as the clinical practice of incidentally detected pulmonary nodules on routine CT scans. Most lung cancer screening trials present results for baseline and incidence screening rounds separately, clustering pulmonary nodules initially found at baseline screening and newly detected pulmonary nodules after baseline screening together. This approach does not appreciate possible differences among pulmonary nodules detected at baseline and firstly detected at incidence screening rounds and is heavily influenced by methodological differences of the respective screening trials. This review intends to create a basis for assessing non-calcified pulmonary nodules detected during LDCT lung cancer screening in a more clinical relevant manner. The aim is to present data of non-calcified pulmonary baseline nodules and new non-calcified pulmonary incident nodules without clustering them together, thereby also simplifying translation to the clinical practice of incidentally detected pulmonary nodules. Small pulmonary nodules newly detected at incidence screening rounds of LDCT lung cancer screening may possess a greater lung cancer probability than pulmonary baseline nodules at a smaller size, which is essential for the development of new guidelines.

  6. Effects of CT dose and nodule characteristics on lung-nodule detectability in a cohort of 90 national lung screening trial patients

    Science.gov (United States)

    Young, Stefano; Lo, Pechin; Hoffman, John M.; Kim, H. J. Grace; Brown, Matthew S.; McNitt-Gray, Michael F.

    2016-03-01

    Lung cancer screening CT is already performed at low dose. There are many techniques to reduce the dose even further, but it is not clear how such techniques will affect nodule detectability. In this work, we used an in-house CAD algorithm to evaluate detectability. 90348 patients and their raw CT data files were drawn from the National Lung Screening Trial (NLST) database. All scans were acquired at ~2 mGy CTDIvol with fixed tube current, 1 mm slice thickness, and B50 reconstruction kernel on a Sensation 64 scanner (Siemens Healthcare). We used the raw CT data to simulate two additional reduced-dose scans for each patient corresponding to 1 mGy (50%) and 0.5 mGy (25%). Radiologists' findings on the NLST reader forms indicated 65 nodules in the cohort, which we subdivided based on LungRADS criteria. For larger category 4 nodules, median sensitivities were 100% at all three dose levels, and mean sensitivity decreased with dose. For smaller nodules meeting the category 2 or 3 criteria, the dose dependence was less obvious. Overall, mean patient-level sensitivity varied from 38.5% at 100% dose to 40.4% at 50% dose, a difference of only 1.9%. However, the false-positive rate quadrupled from 1 per case at 100% dose to 4 per case at 25% dose. Dose reduction affected lung-nodule detectability differently depending on the LungRADS category, and the false-positive rate was very sensitive at sub-screening dose levels. Thus, care should be taken to adapt CAD for the very challenging noise characteristics of screening.

  7. Lung nodules in pediatric oncology patients: a prediction rule for when to biopsy.

    Science.gov (United States)

    Murrell, Zaria; Dickie, Belinda; Dasgupta, Roshni

    2011-05-01

    The purpose of the study was to develop a prediction rule regarding the factors that most accurately predict the diagnosis of a malignancy in a lung nodule in the pediatric oncology patient. A retrospective review of pediatric oncology patients that underwent lung nodule resection between 1998 and 2007 was performed. Multivariable logistic regression was used to create a prediction rule. Fifty pediatric oncology patients underwent 21 thoracotomies and 48 thoracoscopies to resect discrete lung nodules seen on computed tomographic scans during workup for metastasis or routine surveillance. The mean nodule size was 10.43 ± 7.08 mm. The most significant predictors of malignancy in a nodule were peripheral location (odds ratio [OR], 9.1); size between 5 and 10 mm (OR, 2.78); location within the right lower lobe (OR, 2.43); and patients with osteosarcoma (OR, 10.8), Ewing sarcoma (OR, 3.05), or hepatocellular carcinoma (OR, 2.38). Lesions that are between 5 and 10 mm in size and peripherally located in patients with osteosarcoma, Ewing sarcoma, or hepatocellular carcinoma are most likely to be malignant. Use of a prediction rule can help guide clinical practice by determining which patients should undergo surgical resection of lung nodules and which patients may be closely observed with continued radiologic studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. A study on the effect of CT imaging acquisition parameters on lung nodule image interpretation

    Science.gov (United States)

    Yu, Shirley J.; Wantroba, Joseph S.; Raicu, Daniela S.; Furst, Jacob D.; Channin, David S.; Armato, Samuel G., III

    2009-02-01

    Most Computer-Aided Diagnosis (CAD) research studies are performed using a single type of Computer Tomography (CT) scanner and therefore, do not take into account the effect of differences in the imaging acquisition scanner parameters. In this paper, we present a study on the effect of the CT parameters on the low-level image features automatically extracted from CT images for lung nodule interpretation. The study is an extension of our previous study where we showed that image features can be used to predict semantic characteristics of lung nodules such as margin, lobulation, spiculation, and texture. Using the Lung Image Data Consortium (LIDC) dataset, we propose to integrate the imaging acquisition parameters with the low-level image features to generate classification models for the nodules' semantic characteristics. Our preliminary results identify seven CT parameters (convolution kernel, reconstruction diameter, exposure, nodule location along the z-axis, distance source to patient, slice thickness, and kVp) as influential in producing classification rules for the LIDC semantic characteristics. Further post-processing analysis, which included running box plots and binning of values, identified four CT parameters: distance source to patient, kVp, nodule location, and rescale intercept. The identification of these parameters will create the premises to normalize the image features across different scanners and, in the long run, generate automatic rules for lung nodules interpretation independently of the CT scanner types.

  9. Automated detection of lung nodules in CT images using shape-based genetic algorithm.

    Science.gov (United States)

    Dehmeshki, Jamshid; Ye, Xujiong; Lin, Xinyu; Valdivieso, Manlio; Amin, Hamdan

    2007-09-01

    A shape-based genetic algorithm template-matching (GATM) method is proposed for the detection of nodules with spherical elements. A spherical-oriented convolution-based filtering scheme is used as a pre-processing step for enhancement. To define the fitness function for GATM, a 3D geometric shape feature is calculated at each voxel and then combined into a global nodule intensity distribution. Lung nodule phantom images are used as reference images for template matching. The proposed method has been validated on a clinical dataset of 70 thoracic CT scans (involving 16,800 CT slices) that contains 178 nodules as a gold standard. A total of 160 nodules were correctly detected by the proposed method and resulted in a detection rate of about 90%, with the number of false positives at approximately 14.6/scan (0.06/slice). The high-detection performance of the method suggested promising potential for clinical applications.

  10. Shape and texture based novel features for automated juxtapleural nodule detection in lung CTs.

    Science.gov (United States)

    Taşcı, Erdal; Uğur, Aybars

    2015-05-01

    Lung cancer is one of the types of cancer with highest mortality rate in the world. In case of early detection and diagnosis, the survival rate of patients significantly increases. In this study, a novel method and system that provides automatic detection of juxtapleural nodule pattern have been developed from cross-sectional images of lung CT (Computerized Tomography). Shape-based and both shape and texture based 7 features are contributed to the literature for lung nodules. System that we developed consists of six main stages called preprocessing, lung segmentation, detection of nodule candidate regions, feature extraction, feature selection (with five feature ranking criteria) and classification. LIDC dataset containing cross-sectional images of lung CT has been utilized, 1410 nodule candidate regions and 40 features have been extracted from 138 cross-sectional images for 24 patients. Experimental results for 10 classifiers are obtained and presented. Adding our derived features to known 33 features has increased nodule recognition performance from 0.9639 to 0.9679 AUC value on generalized linear model regression (GLMR) for 22 selected features and being reached one of the most successful results in the literature.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yue; Matsumoto, Tsuneo; Hiyama, Atsuto; Miura, Goji; Tanaka, Nobuyuki; Emoto, Takuya; Kawamura, Takeo; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, 755-8505, Yamaguchi (Japan)

    2003-11-01

    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.)

  12. GGO nodule volume-preserving nonrigid lung registration using GLCM texture analysis.

    Science.gov (United States)

    Park, Seongjin; Kim, Bohyoung; Lee, Jeongjin; Goo, Jin Mo; Shin, Yeong-Gil

    2011-10-01

    In lung cancer screening, benign and malignant nodules can be classified through nodule growth assessment by the registration and, then, subtraction between follow-up computed tomography scans. During the registration, the volume of nodule regions in the floating image should be preserved, whereas the volume of other regions in the floating image should be aligned to that in the reference image. However, ground glass opacity (GGO) nodules are very elusive to automatically segment due to their inhomogeneous interior. In other words, it is difficult to automatically define the volume-preserving regions of GGO nodules. In this paper, we propose an accurate and fast nonrigid registration method. It applies the volume-preserving constraint to candidate regions of GGO nodules, which are automatically detected by gray-level cooccurrence matrix (GLCM) texture analysis. Considering that GGO nodules can be characterized by their inner inhomogeneity and high intensity, we identify the candidate regions of GGO nodules based on the homogeneity values calculated by the GLCM and the intensity values. Furthermore, we accelerate our nonrigid registration by using Compute Unified Device Architecture (CUDA). In the nonrigid registration process, the computationally expensive procedures of the floating-image transformation and the cost-function calculation are accelerated by using CUDA. The experimental results demonstrated that our method almost perfectly preserves the volume of GGO nodules in the floating image as well as effectively aligns the lung between the reference and floating images. Regarding the computational performance, our CUDA-based method delivers about 20× faster registration than the conventional method. Our method can be successfully applied to a GGO nodule follow-up study and can be extended to the volume-preserving registration and subtraction of specific diseases in other organs (e.g., liver cancer).

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

    OpenAIRE

    Hua KL; Hsu CH; Hidayati SC; Cheng WH; Chen YJ

    2015-01-01

    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 ...

  14. Investigating the low-dose limits of multidetector CT in lung nodule surveillance.

    Science.gov (United States)

    Paul, N S; Siewerdsen, J H; Patsios, D; Chung, T B

    2007-09-01

    The purpose of this study was to evaluate the factors limiting nodule detection in thoracic computed tomography (CT) and to determine whether prior knowledge of nodule size and attenuation, available from a baseline CT study, influences the minimum radiation dose at which nodule surveillance CT scans can be performed while maintaining current levels of nodule detectability. Multiple nodules varying in attenuation (-509 to + 110 HU) and diameter (1.6 to 9.5 mm) were layered in random and ordered sequences within 2 lung cylinders made of Rando lung material and suspended within a custom-built CT phantom. Multiple CT scans were performed at varying kVp (120, 100, and 80), mA (200, 150, 100, 50, 20, and 10), and beam collimation (5, 2.5, and 1.25 mm) on a four-row multidetector scanner (Lightspeed, General Electric, Milwaukee, WI) using 0.8 s gantry rotation. The corresponding range of radiation dose over which images were acquired was 0.3-26.4 mGy. Nine observers independently performed three specific tasks, namely: (1) To detect a 3.2 mm nodule of 23 HU; (2) To detect 3.2 mm nodules of varying attenuation (-509 to -154 HU); and (3) To detect nodules varying in size (1.6-9 mm) and attenuation (-509 to 110 HU). A two-alternative forced-choice test was used in order to determine the limits of nodule detection in terms of the proportion of correct responses (Pcorr, related to the area under the ROC curve) as a summary metric of observer performance. The radiation dose levels for detection of 99% of nodules in each task were as follows: Task 1 (1 mGy); Task 2 (5 mGy); and Task 3 (7 mGy). The corresponding interobserver confidence limits were 1, 5, and 10 mGy for Tasks 1, 2, and 3, respectively. There was a fivefold increase in the radiation dose required for detection of lower-density nodules (Tasks 1 to 2). Absence of prior knowledge of the nodule size and density (Task 3) corresponds to a significant increase in the minimum required radiation dose. Significant image

  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. Effect of segmentation algorithms on the performance of computerized detection of lung nodules in CT.

    Science.gov (United States)

    Guo, Wei; Li, Qiang

    2014-09-01

    The purpose of this study is to reveal how the performance of lung nodule segmentation algorithm impacts the performance of lung nodule detection, and to provide guidelines for choosing an appropriate segmentation algorithm with appropriate parameters in a computer-aided detection (CAD) scheme. The database consisted of 85 CT scans with 111 nodules of 3 mm or larger in diameter from the standard CT lung nodule database created by the Lung Image Database Consortium. The initial nodule candidates were identified as those with strong response to a selective nodule enhancement filter. A uniform viewpoint reformation technique was applied to a three-dimensional nodule candidate to generate 24 two-dimensional (2D) reformatted images, which would be used to effectively distinguish between true nodules and false positives. Six different algorithms were employed to segment the initial nodule candidates in the 2D reformatted images. Finally, 2D features from the segmented areas in the 24 reformatted images were determined, selected, and classified for removal of false positives. Therefore, there were six similar CAD schemes, in which only the segmentation algorithms were different. The six segmentation algorithms included the fixed thresholding (FT), Otsu thresholding (OTSU), fuzzy C-means (FCM), Gaussian mixture model (GMM), Chan and Vese model (CV), and local binary fitting (LBF). The mean Jaccard index and the mean absolute distance (Dmean) were employed to evaluate the performance of segmentation algorithms, and the number of false positives at a fixed sensitivity was employed to evaluate the performance of the CAD schemes. For the segmentation algorithms of FT, OTSU, FCM, GMM, CV, and LBF, the highest mean Jaccard index between the segmented nodule and the ground truth were 0.601, 0.586, 0.588, 0.563, 0.543, and 0.553, respectively, and the corresponding Dmean were 1.74, 1.80, 2.32, 2.80, 3.48, and 3.18 pixels, respectively. With these segmentation results of the six

  17. Acetylsalicylic Acid Compared to Placebo in Treating High-Risk Patients With Subsolid Lung Nodules | Division of Cancer Prevention

    Science.gov (United States)

    This randomized phase II trial studies acetylsalicylic acid compared to placebo in treating high-risk patients with subsolid lung nodules. A nodule is a growth or lump that may be malignant (cancer) or benign (not cancer). Chemoprevention is the use of drugs to keep cancer from forming or coming back. The use of acetylsalicylic acid may keep cancer from forming in patients with subsolid lung nodules. |

  18. Lung nodule malignancy prediction using multi-task convolutional neural network

    Science.gov (United States)

    Li, Xiuli; Kao, Yueying; Shen, Wei; Li, Xiang; Xie, Guotong

    2017-03-01

    In this paper, we investigated the problem of diagnostic lung nodule malignancy prediction using thoracic Computed Tomography (CT) screening. Unlike most existing studies classify the nodules into two types benign and malignancy, we interpreted the nodule malignancy prediction as a regression problem to predict continuous malignancy level. We proposed a joint multi-task learning algorithm using Convolutional Neural Network (CNN) to capture nodule heterogeneity by extracting discriminative features from alternatingly stacked layers. We trained a CNN regression model to predict the nodule malignancy, and designed a multi-task learning mechanism to simultaneously share knowledge among 9 different nodule characteristics (Subtlety, Calcification, Sphericity, Margin, Lobulation, Spiculation, Texture, Diameter and Malignancy), and improved the final prediction result. Each CNN would generate characteristic-specific feature representations, and then we applied multi-task learning on the features to predict the corresponding likelihood for that characteristic. We evaluated the proposed method on 2620 nodules CT scans from LIDC-IDRI dataset with the 5-fold cross validation strategy. The multitask CNN regression result for regression RMSE and mapped classification ACC were 0.830 and 83.03%, while the results for single task regression RMSE 0.894 and mapped classification ACC 74.9%. Experiments show that the proposed method could predict the lung nodule malignancy likelihood effectively and outperforms the state-of-the-art methods. The learning framework could easily be applied in other anomaly likelihood prediction problem, such as skin cancer and breast cancer. It demonstrated the possibility of our method facilitating the radiologists for nodule staging assessment and individual therapeutic planning.

  19. 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.

  20. 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.

  1. Progressive intraparenchymal lung nodules dissemination in a heavy smoker and seropositive rheumatoid arthritis suspected of tuberculosis relapse.

    Science.gov (United States)

    Arghir, Oana Cristina; Niţu, Mimi; Trenchea, Mihaela; Ciobotaru, Camelia

    2013-01-01

    Anthony Caplan first described rheumatoid lung nodules associated with pneumoconiosis in coal-miners (Caplan, 1953). Intraparenchymal lung nodules were later described in rheumatoid arthritis (RA) patients who were never exposed to coal dust and/or without pneumoconiosis. Rheumatoid lung nodules are usually detected in unselected patients: 0.2% in chest radiography and 4% in high-resolution computed tomography (Nannini et al., 2008). Patients could be reluctant to perform surgical lung biopsy for an accurate histopathological diagnosis. We present a peculiar association between a seropositive RA and a presumptive active tuberculosis (TB) disease in a 59-year-old male patient, ex-smoker with a previously healed pulmonary TB disease. The purpose of this report is to describe an unusual case of a presumptive relapse of the nodular TB disease, which progressed to an extensive nodular bilateral dissemination under anti-tuberculosis therapy, mimicking a metastatic carcinoma. The diagnosis of rheumatoid necrobiotic lung nodules was confirmed after open biopsy left pulmonary was performed. Formalin-fixed paraffin-embedded pulmonary rheumatoid nodules were processed for histology and stained with Masson's trichrome. Central structure of the removed pulmonary nodules is typical of a rheumatoid nodule with central necrosis surrounded by a palisade of macrophages. The accumulation of anthracotic pigment was noticed inside the pulmonary nodules in a RA patient without professional exposure to coal or mineral dust. This rare entity is an appearance of the rheumatoid nodules lung syndrome and anthracosis in a heavy tobacco former smoker.

  2. 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.)

  3. 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

  4. SubSolid Nodules in lung cancer screening

    NARCIS (Netherlands)

    Scholten, E.Th.

    2014-01-01

    With eight million deaths in 2012 lung cancer is the most common cause of cancer death in the world, and the problem is still growing. As long as the goal of a total ban on smoking tobacco is not fulfilled, lung cancer screening as a means of secondary prevention has great potential. The aim of lung

  5. An automated system for lung nodule detection in low-dose computed tomography

    CERN Document Server

    Gori, I; Martinez, A Preite; Retico, A

    2007-01-01

    A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector helical Computed Tomography (CT) images was 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, a dot-enhancement filter for nodule candidate selection 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 results obtained on the collected database of low-dose thin-slice CT scans are shown in terms of free response receiver operating characteristic (FROC) curves and discussed.

  6. Lung amyloid nodule detected by 99mTc-aprotinin scintigraphy.

    Science.gov (United States)

    Ishii, Satoru; Kubota, Kazuo; Minamimoto, Ryogo; Kouketu, Rikiya; Morooka, Miyako; Kawai, Shigeo; Takeda, Yuichiro; Kobayashi, Nobuyuki; Sugiyama, Haruhito

    2012-07-01

    We present a case in which an amyloid lung nodule was diagnosed preoperatively by amyloid scintigraphy (99m)Tc-aprotinin. A 65-year-old man complained of marked weight loss (9 kg) over a period of 6 months. An abnormal shadow in the middle field of the right lung was detected on chest X-ray, corresponding to a 16-mm nodule in the right middle lobe on thoracic computed tomography (CT). Total protein and immunoglobulin G levels were elevated to 8.3 and 2245 mg/dl, respectively, but other blood tests including several tumor marker levels and Cryptococcus antibodies were all within normal range. Fluorodeoxyglucose positron emission tomography showed no uptake by the lung nodule, so lung amyloidosis was considered as differential diagnosis. To avoid risk of bleeding on bronchoscopy, noninvasive amyloid scintigraphy using (99m)Tc-aprotinin was first performed. A nodular, abnormal accumulation was observed in the right middle lung lobe. Diagnostic imaging strongly suggested amyloidosis, so video-assisted thoracic surgery was performed rather than bronchoscopy. Pathological samples showed positive staining with Congo red, and A-λ amyloidosis was diagnosed on the basis of immunostaining. Scintigraphy using (99m)Tc-aprotinin offers a useful, noninvasive method for assessing lung amyloidosis.

  7. 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.

  8. Change descriptors for determining nodule malignancy in national lung screening trial CT screening images

    Science.gov (United States)

    Geiger, Benjamin; Hawkins, Samuel; Hall, Lawrence O.; Goldgof, Dmitry B.; Balagurunathan, Yoganand; Gatenby, Robert A.; Gillies, Robert J.

    2016-03-01

    Pulmonary nodules are effectively diagnosed in CT scans, but determining their malignancy has been a challenge. The rate of change of the volume of a pulmonary nodule is known to be a prognostic factor for cancer development. In this study, we propose that other changes in imaging characteristics are similarly informative. We examined the combination of image features across multiple CT scans, taken from the National Lung Screening Trial, with individual scans of the same patient separated by approximately one year. By subtracting the values of existing features in multiple scans for the same patient, we were able to improve the ability of existing classification algorithms to determine whether a nodule will become malignant. We trained each classifier on 83 nodules determined to be malignant by biopsy and 172 nodules determined to be benign by their clinical stability through two years of no change; classifiers were tested on 77 malignant and 144 benign nodules, using a set of features that in a test-retest experiment were shown to be stable. An accuracy of 83.71% and AUC of 0.814 were achieved with the Random Forests classifier on a subset of features determined to be stable via test-retest reproducibility analysis, further reduced with the Correlation-based Feature Selection algorithm.

  9. A parameterized logarithmic image processing method with Laplacian of Gaussian filtering for lung nodule enhancement in chest radiographs.

    Science.gov (United States)

    Chen, Sheng; Yao, Liping; Chen, Bao

    2016-11-01

    The enhancement of lung nodules in chest radiographs (CXRs) plays an important role in the manual as well as computer-aided detection (CADe) lung cancer. In this paper, we proposed a parameterized logarithmic image processing (PLIP) method combined with the Laplacian of a Gaussian (LoG) filter to enhance lung nodules in CXRs. We first applied several LoG filters with varying parameters to an original CXR to enhance the nodule-like structures as well as the edges in the image. We then applied the PLIP model, which can enhance lung nodule images with high contrast and was beneficial in extracting effective features for nodule detection in the CADe scheme. Our method combined the advantages of both the PLIP algorithm and the LoG algorithm, which can enhance lung nodules in chest radiographs with high contrast. To test our nodule enhancement method, we tested a CADe scheme, with a relatively high performance in nodule detection, using a publically available database containing 140 nodules in 140 CXRs enhanced through our nodule enhancement method. The CADe scheme attained a sensitivity of 81 and 70 % with an average of 5.0 frame rate (FP) and 2.0 FP, respectively, in a leave-one-out cross-validation test. By contrast, the CADe scheme based on the original image recorded a sensitivity of 77 and 63 % at 5.0 FP and 2.0 FP, respectively. We introduced the measurement of enhancement by entropy evaluation to objectively assess our method. Experimental results show that the proposed method obtains an effective enhancement of lung nodules in CXRs for both radiologists and CADe schemes.

  10. Digital tomosynthesis of the thorax - The influence of respiratory motion artifacts on lung nodule detection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Mok; Chung, Myung Jin; Lee, Kyung Soo; Kang, Hee; Song, In-Young; Lee, Eun Joo; Hwang, Hye Sun [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)], e-mail: mj1.chung@samsung.com

    2013-07-15

    Background: Digital tomosynthesis considerably reduces problems created by overlapping anatomy compared with chest X-ray (CXR). However, digital tomosynthesis requires a longer scan time compared with CXR, and thus may be vulnerable to motion artifacts. Purpose: To compare the diagnostic performance of digital tomosynthesis in subjects with and without respiratory motion artifacts. Material and Methods: The institutional review board approved this retrospective study, and the requirement for written informed consent was waived. A total of 46 subjects with imaging containing respiratory motion artifacts were enrolled in this study, 18 of whom were positive and 28 of whom were negative for lung nodules on computed tomography (CT). The control group was comprised of 92 age-matched subjects with imaging devoid of motion artifacts. Of these, 36 were positive and 56 were negative for lung nodules on subsequent CT scan. The size criteria of nodules were 4-0 mm. Three chest radiologists independently evaluated the radiographs and digital tomosynthesis images for the presence of pulmonary nodules. Multireader multicase receiver-operating characteristic (ROC) analyses was used for statistical comparisons. Results: Within the control group, the areas under curve (AUC) for observer performances in detecting lung nodules on digital tomosynthesis was higher than that on CXR (P = 0.017). Within the study group, there were no significant differences in AUCs for observer performances (P = 0.576). Conclusion: When no motion artifacts are present, the detection performance of nodules (4-10 mm) on digital tomosynthesis is significantly better than that on CXR, whereas there is not a significant difference in cases with motion artifacts.

  11. Optimization of nodule management in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein Anne

    2015-01-01

    Lung cancer is the leading cancer-related cause of death. Through computed tomography (CT) screening, cancer can be detected at the earliest stage, with a much greater probability of cure. After the positive outcome of the US National Lung Screening Trial (NLST), screening with low-dose CT in heavy

  12. Brain nodules with lung mass: are they always metastases?

    Science.gov (United States)

    Jorcano, Sandra; Farrús, Blanca; Pujol, Teresa; Verger, Eugenia; Marruecos, Jordi; Conill, Carlos

    2008-08-01

    In a smoking adult with a lung mass, brain masses are usually diagnosed as brain metastases of lung origin. Nevertheless, differential diagnosis between cerebral abscesses cannot be performed based on clinical symptoms or imaging technologies, and histological diagnosis is essential. This case illustrates the advisability of always obtaining histological diagnosis of the primary tumor and/or cerebral lesion before introducing any oncological treatment.

  13. A Simple and Safe Technique for CT Guided Lung Nodule Marking prior to Video Assisted Thoracoscopic Surgical Resection Revisited

    Directory of Open Access Journals (Sweden)

    James A. Stephenson

    2015-01-01

    Full Text Available Aim. We describe our experience of a simple, safe, and reproducible technique for lung nodule marking prethoracoscopic metastasectomy. Thoracoscopic lung nodule resection reduces patient discomfort, complications, higher level of care, hospital stay, and cost; however, small deeply placed lung nodules are difficult to locate and resect thoracoscopically. Materials and Methods. We describe and review the success of our novel technique, where nodules are identified on a low dose CT and marked with methylene blue using CT fluoroscopy guidance immediately prior to surgery. Results. 30 nodules were marked with a mean size of 8 mm (4–18 mm located at a mean depth of 17 mm, distributed through both lungs. Dye was detected at the pleural surface in 97% of the patients and at the nodule in 93%. There were no major complications. Thoracoscopic resection was possible in 90%. Conclusion. This is a simple and safe method of lung nodule marking to facilitate thoracoscopic resection in cases where this may not be technically possible due to nodule location.

  14. Fully automatic lung segmentation and rib suppression methods to improve nodule detection in chest radiographs.

    Science.gov (United States)

    Soleymanpour, Elaheh; Pourreza, Hamid Reza; Ansaripour, Emad; Yazdi, Mehri Sadooghi

    2011-07-01

    Computer-aided Diagnosis (CAD) systems can assist radiologists in several diagnostic tasks. Lung segmentation is one of the mandatory steps for initial detection of lung cancer in Posterior-Anterior chest radiographs. On the other hand, many CAD schemes in projection chest radiography may benefit from the suppression of the bony structures that overlay the lung fields, e.g. ribs. The original images are enhanced by an adaptive contrast equalization and non-linear filtering. Then an initial estimation of lung area is obtained based on morphological operations and then it is improved by growing this region to find the accurate final contour, then for rib suppression, we use oriented spatial Gabor filter. The proposed method was tested on a publicly available database of 247 chest radiographs. Results show that this method outperformed greatly with accuracy of 96.25% for lung segmentation, also we will show improving the conspicuity of lung nodules by rib suppression with local nodule contrast measures. Because there is no additional radiation exposure or specialized equipment required, it could also be applied to bedside portable chest x-rays. In addition to simplicity of these fully automatic methods, lung segmentation and rib suppression algorithms are performed accurately with low computation time and robustness to noise because of the suitable enhancement procedure.

  15. 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.

  16. Inter-reader variability when applying the 2013 Fleischner guidelines for potential solitary subsolid lung nodules.

    Science.gov (United States)

    Penn, Alex; Ma, Mingming; Chou, Benjamin B; Tseng, Jeffrey R; Phan, Peter

    2015-10-01

    In 2013, the Fleischner Society published recommendations for managing subsolid pulmonary nodules. Inter-reader variability has not yet been defined and has potential implications for the ease and reproducibility of applying the guidelines to clinical practice. To evaluate inter-reader variability when applying the 2013 Fleischner guidelines for potential solitary subsolid lung nodules. Potential nodules were identified through a systematic retrospective review of CT studies that reported a ground-glass lesion. Three radiologists decided whether these lesions fit criteria of a subsolid nodule and thus merit application of the Fleischner Society guidelines, determined if a solid component was present, and measured each component in two dimensions. Final management recommendations were based on these intermediate decisions. Inter-reader variability for management was calculated and Fleiss' kappa was used to determine significance. Logistic regression and Fisher's exact test determined whether management was contingent on each intermediate decision. Forty-four nodules with mean diameter of 9.4 mm were evaluated by three radiologists. Final management recommendations were in agreement for 93 out of 132 cases (70.4%, kappa = 0.56). Inter-reader variability in management recommendation was contingent on disagreement over whether a pulmonary lesion fit criteria of a subsolid nodule for 24 cases (P reader variability when applying the 2013 Fleischner Society management recommendations. Significant contributors of variability include whether the potential lesions fit subsolid nodule criteria and whether a solid component is present. Measurement variability does not significantly affect the final management decisions. © The Foundation Acta Radiologica 2014.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cascio, D. [Dipt. di Fisica e Tecnologie Relative, Univ. di Palermo (Italy); Cheran, S.C. [Dipt. di Fisica, Univ. di Genova (Italy); Ist. Nazionale di Fisica Nucleare, Sezione di Torino (Italy); Chincarini, A. [Ist. Nazionale di Fisica Nucleare, Sezione di Genova (Italy); De Nunzio, G. [Dipt. di Scienza dei Materiali, Univ. di Lecce (Italy); Delogu, P.; Fantacci, M.E. [Dipt. di Fisica, Univ. di Pisa (Italy); Ist. Nazionale di Fisica Nucleare, Sezione di Pisa (Italy); Gargano, G. [Dipt. Interateneo di Fisica M. Merlin, Univ. di Bari (Italy); Ist. Nazionale di Fisica Nucleare, Sezione di Bari (Italy); Gori, I.; Retico, A. [Ist. Nazionale di Fisica Nucleare, Sezione di Pisa (Italy); Masala, G.L. [Struttura Dipartimentale di Matematica e Fisica, Univ. di Sassari (Italy); Ist. Nazionale di Fisica Nucleare, Sezione di Cagliari (Italy); Preite Martinez, A. [Centro Studi e Ricerche Enrico Fermi, Roma (Italy); Santoro, M. [Dipt. di Scienze Fisiche, Univ. di Napoli (Italy); Spinelli, C. [Unita Operativa Radiodiagnostica 2, Azienda Ospedaliera Universitaria Pisana, Pisa (Italy); Tarantino, T. [Divisione di Radiologia Diagnostica e Interventistica del Dipt. di Oncologia, Trapianti e Nuove Tecnologie in Medicina, Univ. di Pisa (Italy)

    2007-06-15

    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 ({proportional_to}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.)

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

    CERN Document Server

    Cascio, D; Chincarini, A; De Nunzio, G; Delogu, P; Fantacci, M E; Gargano, G; Gori, I; Masala, G L; Martinez, A Preite; Retico, 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 hig...

  19. 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

    2017-08-04

    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

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

    OpenAIRE

    Hugh J Freeman; Jennifer E Davis; Marcia E Prest; Edward J Lawson

    2004-01-01

    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 immunosuppressi...

  1. 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

  2. Evaluation of a projection-domain lung nodule insertion technique in thoracic CT

    Science.gov (United States)

    Ma, Chi; Chen, Baiyu; Koo, Chi Wan; Takahashi, Edwin A.; Fletcher, Joel G.; McCollough, Cynthia H.; Levin, David L.; Kuzo, Ronald S.; Viers, Lyndsay D.; Vincent Sheldon, Stephanie A.; Leng, Shuai; Yu, Lifeng

    2016-04-01

    Task-based assessment of computed tomography (CT) image quality requires a large number of cases with ground truth. Inserting lesions into existing cases to simulate positive cases is a promising alternative approach. The aim of this study was to evaluate a recently-developed raw-data based lesion insertion technique in thoracic CT. Lung lesions were segmented from patient CT images, forward projected, and reinserted into the same patient CT projection data. In total, 32 nodules of various attenuations were segmented from 21 CT cases. Two experienced radiologists and 2 residents blinded to the process independently evaluated these inserted nodules in two sub-studies. First, the 32 inserted and the 32 original nodules were presented in a randomized order and each received a rating score from 1 to 10 (1=absolutely artificial to 10=absolutely realistic). Second, the inserted and the corresponding original lesions were presented side-by-side to each reader, who identified the inserted lesion and provided a confidence score (1=no confidence to 5=completely certain). For the randomized evaluation, discrimination of real versus artificial nodules was poor with areas under the receiver operative characteristic curves being 0.69 (95% CI: 0.58-0.78), 0.57 (95% CI: 0.46-0.68), and 0.62 (95% CI: 0.54-0.69) for the 2 radiologists, 2 residents, and all 4 readers, respectively. For the side-by-side evaluation, although all 4 readers correctly identified inserted lesions in 103/128 pairs, the confidence score was moderate (2.6). Our projection-domain based lung nodule insertion technique provides a robust method to artificially generate clinical cases that prove to be difficult to differentiate from real cases.

  3. 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.

  4. Rapid Growth of Lung Nodules due to Combined Pulmonary Vasculitis, Silicoanthracosis, and Chondrocalcinosis

    Directory of Open Access Journals (Sweden)

    Wolfgang Jungraithmayr

    2016-01-01

    Full Text Available Background. Silicoanthracosis is a pneumoconiosis due to occupational inhalation of silica and carbon dusts. Clinically, it can be associated with vasculitis or rheumatoid arthritis. In association with these diseases, silicoanthracosis can present within the lung with multiple pulmonary nodules which, as a differential diagnosis, can mimic metastatic disease or multiple abscesses. Case Presentation. We present the case of a 62-year old former pit worker with pulmonary nodules, chondrocalcinosis due to calcium pyrophosphate deposition (CPPD, and a history of renal cancer. Within a short period of time, pulmonary nodules grew rapidly. Thoracoscopically, the resected lung specimen revealed silicoanthracosis associated with small-to-medium-size vasculitis in the presence of antineutrophil cytoplasmatic autoantibodies (c-ANCA. Conclusion. Pulmonary silicoanthracotic lesions on the base of ANCA-associated vasculitis and CPPD arthritis can rapidly grow. A mutual correlation between silicoanthracosis, ANCA-associated vasculitis, and CPPD seems possible. Apart from this, consideration of metastatic disease should be obligatory in patients with a history of cancer at the same time being immunosuppressed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yue; Matsumoto, Tsuneo; Hiyama, Atsuto; Miura, Goji; Tanaka, Nobuyuki; Matsunaga, Naofumi [Yamaguchi Univ., Ube (Japan). School of Medicine

    2002-10-01

    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)

  6. A unified methodology based on sparse field level sets and boosting algorithms for false positives reduction in lung nodules detection.

    Science.gov (United States)

    Saien, Soudeh; Moghaddam, Hamid Abrishami; Fathian, Mohsen

    2017-08-09

    This work aims to develop a unified methodology for the false positives reduction in lung nodules computer-aided detection schemes. The 3D region of each detected nodule candidate is first reconstructed using the sparse field method for accurately segmenting the objects. This technique enhances the level set modeling by restricting the computations to a narrow band near the evolving curve. Then, a set of 2D and 3D relevant features are extracted for each segmented candidate. Subsequently, a hybrid undersampling/boosting algorithm called RUSBoost is applied to analyze the features and discriminate real nodules from non-nodules. The performance of the proposed scheme was evaluated by using 70 CT images, randomly selected from the Lung Image Database Consortium and containing 198 nodules. Applying RUSBoost classifier exhibited a better performance than some commonly used classifiers. It effectively reduced the average number of FPs to only 3.9 per scan based on a fivefold cross-validation. The practical implementation, applicability for different nodule types and adaptability in handling the imbalanced data classification insure the improvement in lung nodules detection by utilizing this new approach.

  7. Computer-aided detection of lung cancer: combining pulmonary nodule detection systems with a tumor risk prediction model

    Science.gov (United States)

    Setio, Arnaud A. A.; Jacobs, Colin; Ciompi, Francesco; van Riel, Sarah J.; Winkler Wille, Mathilde M.; Dirksen, Asger; van Rikxoort, Eva M.; van Ginneken, Bram

    2015-03-01

    Computer-Aided Detection (CAD) has been shown to be a promising tool for automatic detection of pulmonary nodules from computed tomography (CT) images. However, the vast majority of detected nodules are benign and do not require any treatment. For effective implementation of lung cancer screening programs, accurate identification of malignant nodules is the key. We investigate strategies to improve the performance of a CAD system in detecting nodules with a high probability of being cancers. Two strategies were proposed: (1) combining CAD detections with a recently published lung cancer risk prediction model and (2) the combination of multiple CAD systems. First, CAD systems were used to detect the nodules. Each CAD system produces markers with a certain degree of suspicion. Next, the malignancy probability was automatically computed for each marker, given nodule characteristics measured by the CAD system. Last, CAD degree of suspicion and malignancy probability were combined using the product rule. We evaluated the method using 62 nodules which were proven to be malignant cancers, from 180 scans of the Danish Lung Cancer Screening Trial. The malignant nodules were considered as positive samples, while all other findings were considered negative. Using a product rule, the best proposed system achieved an improvement in sensitivity, compared to the best individual CAD system, from 41.9% to 72.6% at 2 false positives (FPs)/scan and from 56.5% to 88.7% at 8 FPs/scan. Our experiment shows that combining a nodule malignancy probability with multiple CAD systems can increase the performance of computerized detection of lung cancer.

  8. Cavitary pulmonary nodules in atypical collagen disease and lupoid drug reaction. Report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Muren, C.; Strandberg, O.

    The case histories of two patients with cavitary pulmonary nodules and the findings at chest radiography are reviewed. The first patient had a connective tissue disease with features common to systematic lupus erythematosus and Wegener's granulomatosis. In the second patient the lung changes developed as part of a drug reaction to carbamezapine and/or phenytoin. The common denominator of the cavitating nodules is probably the presence of granulomas, developing as a sequela of pulmonary vasculitis. (orig.).

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

    Energy Technology Data Exchange (ETDEWEB)

    Knoess, Naomi; Hoffmann, B.; Fabel, M.; Wiese, C.; Bolte, H.; Heller, M.; Biederer, J. [Klinik fuer Diagnostische Radiologie, Universitaetsklinikum Schleswig-Holstein, Campus Kiel (Germany); Jochens, A. [Inst. fuer Medizinische Informatik und Statistik, Universitaetsklinikum Schleswig-Holstein Campus Kiel (Germany)

    2009-12-15

    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.)

  10. Limited Wegener's granulomatosis presenting as lung nodules in a patient with rheumatoid arthritis: a case report.

    Science.gov (United States)

    Pai, Sushma; Panda, Mukta

    2008-12-23

    Rheumatoid arthritis has varied pleuroparenchymal manifestations. Wegener's granulomatosis can develop in an established case of rheumatoid arthritis and this association although previously reported is very rare. A 60-year-old lady had been diagnosed with rheumatoid arthritis on the basis of her clinical symptoms and serological tests which were positive RA factor and anti-CCP antibodies. Her rheumatoid arthritis activity had been mild and well controlled with hydroxychloroquine and low dose prednisone. She presented with a productive cough and right-sided pleuritic chest pain. CT scan of the chest showed three lung nodules with increased uptake on PET CT scan, raising concerns for an inflammatory or malignant process. The differential diagnosis included rheumatoid nodules, infections or malignancy. A CT-guided needle biopsy of the largest nodule was undertaken which showed vasculitis typical of Wegener's granulomatosis. Stains and cultures of the biopsy specimen were negative for bacteria, fungi and acid fast bacilli. A panel of serological tests for vasculitis were checked and showed elevated titers of cANCA and anti-proteinase 3 antibodies. Urine analysis and CT scan of paranasal sinuses was normal. Since the upper respiratory tract and the kidneys were spared a diagnosis of limited Wegener's granulomatosis affecting only the lungs was made. Due to the toxicity of cyclophosphamide, her relatively mild disease sparing the kidneys and the underlying rheumatoid arthritis, weekly methotrexate was started and low dose prednisone was continued. She had marked symptomatic improvement and complete resolution of the nodules was documented on subsequent imaging. Wegener's granulomatosis developing in a patient with rheumatoid arthritis is very rare but should be considered as it warrants a different and possibly more aggressive treatment approach.

  11. Intussuscepting Ampullary Adenoma: An Unusual Cause of Gastric Outlet Obstruction Leading to Cavitating Lung Lesions

    Directory of Open Access Journals (Sweden)

    Simon J. McCluney

    2016-10-01

    Full Text Available Ampullary adenomas are a rare clinical entity, occurring at a rate of 0.04–0.12% in the general population. They are premalignant lesions which have the capability to progress to malignancy, and they should be excised if they are causing immediate symptoms and/or are likely to degenerate to carcinoma. Intestinal intussusception in adults is rare and, unlike in children, is often due to a structural pathology. Intussuscepting duodenal/ampullary adenomas have been reported in the literature on 13 previous occasions, however never before with this presentation. We report the case of a woman who presented with a 1-year history of recurrent chest infections. She was treated with numerous antibiotics, whilst intermittent symptoms of recurrent vomiting and weight loss were initially attributed to her lung infections. A chest CT demonstrated multiple cavitating lung lesions, whilst an obstructing polypoid mass was noted at D2 on dedicated abdominal imaging. Due to ongoing nutritional problems, she had a semi-urgent pancreaticoduodenectomy. Intraoperative findings demonstrated a large mass at D2 with a duodeno-duodenal intussusception. Histological analysis reported a duodenal, ampullary, low-grade tubular adenoma, 75 × 28 × 30 mm in size, with intussusception and complete resection margins. The patient recovered well and was discharged on postoperative day 10, with no complications to date. Ampullary adenomas may present with obstruction of the main gastrointestinal tract and/or biliary/pancreatic ducts. Common presentations include gastric outlet obstruction, gastrointestinal bleeding or acute pancreatitis. This unique presentation should remind clinicians of the need to investigate recurrent chest infections for a possible gastrointestinal cause.

  12. CT scan screening for lung cancer: risk factors for nodules and malignancy in a high-risk urban cohort.

    Directory of Open Access Journals (Sweden)

    Alissa K Greenberg

    Full Text Available BACKGROUND: Low-dose computed tomography (CT for lung cancer screening can reduce lung cancer mortality. The National Lung Screening Trial reported a 20% reduction in lung cancer mortality in high-risk smokers. However, CT scanning is extremely sensitive and detects non-calcified nodules (NCNs in 24-50% of subjects, suggesting an unacceptably high false-positive rate. We hypothesized that by reviewing demographic, clinical and nodule characteristics, we could identify risk factors associated with the presence of nodules on screening CT, and with the probability that a NCN was malignant. METHODS: We performed a longitudinal lung cancer biomarker discovery trial (NYU LCBC that included low-dose CT-screening of high-risk individuals over 50 years of age, with more than 20 pack-year smoking histories, living in an urban setting, and with a potential for asbestos exposure. We used case-control studies to identify risk factors associated with the presence of nodules (n=625 versus no nodules (n=557, and lung cancer patients (n=30 versus benign nodules (n=128. RESULTS: The NYU LCBC followed 1182 study subjects prospectively over a 10-year period. We found 52% to have NCNs >4 mm on their baseline screen. Most of the nodules were stable, and 9.7% of solid and 26.2% of sub-solid nodules resolved. We diagnosed 30 lung cancers, 26 stage I. Three patients had synchronous primary lung cancers or multifocal disease. Thus, there were 33 lung cancers: 10 incident, and 23 prevalent. A sub-group of the prevalent group were stable for a prolonged period prior to diagnosis. These were all stage I at diagnosis and 12/13 were adenocarcinomas. CONCLUSIONS: NCNs are common among CT-screened high-risk subjects and can often be managed conservatively. Risk factors for malignancy included increasing age, size and number of nodules, reduced FEV1 and FVC, and increased pack-years smoking. A sub-group of screen-detected cancers are slow-growing and may contribute to over

  13. 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

  14. Lung nodule detection in a high-risk population: Comparison of magnetic resonance imaging and low-dose computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregor, E-mail: gregor.sommer@usb.ch [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel (Switzerland); Tremper, Jan, E-mail: j.tremper@dkfz.de [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik Heidelberg gGmbH, Amalienstr. 5, 69126 Heidelberg (Germany); Department of Radiology, University Hospital of the School of Medicine of Ribeirao Preto – University of Sao Paulo, Av. Bandeirantes 3900, Campus Universitario Monte Alegre, 14048 900 Ribeirao Preto, SP (Brazil); Delorme, Stefan, E-mail: s.delorme@dkfz.de [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Becker, Nikolaus, E-mail: n.becker@dkfz.de [Division of Cancer Epidemiology (C020), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg (Germany); Biederer, Jürgen, E-mail: juergen.biederer@uni-heidelberg.de [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); and others

    2014-03-15

    Objective: To investigate the potential of MRI for lung nodule detection in a high-risk population in comparison to low-dose CT. Methods: 49 participants (31 men, 18 women, 51–71 years) of the German Lung Cancer Screening and Intervention Trial (LUSI) with a cancer-suspicious lung lesion in CT were examined with non-contrast-enhanced MRI of the lung at 1.5 T. Data were pseudonymized and presented at random order together with 30 datasets (23 in men, 7 in women, 18–64 years) from healthy volunteers. Two radiologists read the data for the presence of nodules. Sensitivity and specificity were calculated. Gold standard was either histology or long-term follow-up. Contrast-to-Noise-Ratio (CNR) was measured for all detected lesions in all MRI sequences. Results: Average maximum diameter of the lesions was 15 mm. Overall sensitivity and specificity of MRI were 48% (26/54) and 88% (29/33) compared to low-dose CT. Sensitivity of MRI was significantly higher for malignant nodules (78% (12.5/16)) than for benign ones (36% (13.5/38); P = 0.007). There was no statistically significant difference in sensitivity between nodules (benign and malignant) larger or smaller than 10 mm (P = 0.7). Inter observer agreement was 84% (κ = 0.65). Lesion-to-background CNR of T2-weighted single-shot turbo-spin-echo was significantly higher for malignant nodules (89 ± 27) than for benign ones (56 ± 23; P = 0.002). Conclusion: The sensitivity of MRI for detection of malignant pulmonary nodules in a high-risk population is 78%. Due to its inherent soft tissue contrast, MRI is more sensitive to malignant nodules than to benign ones. MRI may therefore represent a useful test for early detection of lung cancer.

  15. Automatic segmentation of pulmonary nodules on CT images by use of NCI lung image database consortium

    Science.gov (United States)

    Tachibana, Rie; Kido, Shoji

    2006-03-01

    Accurate segmentation of small pulmonary nodules (SPNs) on thoracic CT images is an important technique for volumetric doubling time estimation and feature characterization for the diagnosis of SPNs. Most of the nodule segmentation algorithms that have been previously presented were designed to handle solid pulmonary nodules. However, SPNs with ground-glass opacity (GGO) also affects a diagnosis. Therefore, we have developed an automated volumetric segmentation algorithm of SPNs with GGO on thoracic CT images. This paper presents our segmentation algorithm with multiple fixed-thresholds, template-matching method, a distance-transformation method, and a watershed method. For quantitative evaluation of the performance of our algorithm, we used the first dataset provided by NCI Lung Image Database Consortium (LIDC). In the evaluation, we employed the coincident rate which was calculated with both the computerized segmented region of a SPN and the matching probability map (pmap) images provided by LIDC. As the result of 23 cases, the mean of the total coincident rate was 0.507 +/- 0.219. From these results, we concluded that our algorithm is useful for extracting SPNs with GGO and solid pattern as well as wide variety of SPNs in size.

  16. 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.

  17. Computerized lung nodule detection using 3D feature extraction and learning based algorithms.

    Science.gov (United States)

    Ozekes, Serhat; Osman, Onur

    2010-04-01

    In this paper, a Computer Aided Detection (CAD) system based on three-dimensional (3D) feature extraction is introduced to detect lung nodules. First, eight directional search was applied in order to extract regions of interests (ROIs). Then, 3D feature extraction was performed which includes 3D connected component labeling, straightness calculation, thickness calculation, determining the middle slice, vertical and horizontal widths calculation, regularity calculation, and calculation of vertical and horizontal black pixel ratios. To make a decision for each ROI, feed forward neural networks (NN), support vector machines (SVM), naive Bayes (NB) and logistic regression (LR) methods were used. These methods were trained and tested via k-fold cross validation, and results were compared. To test the performance of the proposed system, 11 cases, which were taken from Lung Image Database Consortium (LIDC) dataset, were used. ROC curves were given for all methods and 100% detection sensitivity was reached except naive Bayes.

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

    Science.gov (United States)

    Hua, Kai-Lung; Hsu, Che-Hao; Hidayati, Shintami Chusnul; Cheng, Wen-Huang; Chen, Yu-Jen

    2015-01-01

    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.

  19. Content-Based Image Retrieval System for Pulmonary Nodules: Assisting Radiologists in Self-Learning and Diagnosis of Lung Cancer.

    Science.gov (United States)

    Dhara, Ashis Kumar; Mukhopadhyay, Sudipta; Dutta, Anirvan; Garg, Mandeep; Khandelwal, Niranjan

    2017-02-01

    Visual information of similar nodules could assist the budding radiologists in self-learning. This paper presents a content-based image retrieval (CBIR) system for pulmonary nodules, observed in lung CT images. The reported CBIR systems of pulmonary nodules cannot be put into practice as radiologists need to draw the boundary of nodules during query formation and feature database creation. In the proposed retrieval system, the pulmonary nodules are segmented using a semi-automated technique, which requires a seed point on the nodule from the end-user. The involvement of radiologists in feature database creation is also reduced, as only a seed point is expected from radiologists instead of manual delineation of the boundary of the nodules. The performance of the retrieval system depends on the accuracy of the segmentation technique. Several 3D features are explored to improve the performance of the proposed retrieval system. A set of relevant shape and texture features are considered for efficient representation of the nodules in the feature space. The proposed CBIR system is evaluated for three configurations such as configuration-1 (composite rank of malignancy "1","2" as benign and "4","5" as malignant), configuration-2 (composite rank of malignancy "1","2", "3" as benign and "4","5" as malignant), and configuration-3 (composite rank of malignancy "1","2" as benign and "3","4","5" as malignant). Considering top 5 retrieved nodules and Euclidean distance metric, the precision achieved by the proposed method for configuration-1, configuration-2, and configuration-3 are 82.14, 75.91, and 74.27 %, respectively. The performance of the proposed CBIR system is close to the most recent technique, which is dependent on radiologists for manual segmentation of nodules. A computer-aided diagnosis (CAD) system is also developed based on CBIR paradigm. Performance of the proposed CBIR-based CAD system is close to performance of the CAD system using support vector machine.

  20. Automatic detection of lung nodules in computed tomography images: training and validation of algorithms using public research databases

    Science.gov (United States)

    Camarlinghi, Niccolò

    2013-09-01

    Lung cancer is one of the main public health issues in developed countries. Lung cancer typically manifests itself as non-calcified pulmonary nodules that can be detected reading lung Computed Tomography (CT) images. To assist radiologists in reading images, researchers started, a decade ago, the development of Computer Aided Detection (CAD) methods capable of detecting lung nodules. In this work, a CAD composed of two CAD subprocedures is presented: , devoted to the identification of parenchymal nodules, and , devoted to the identification of the nodules attached to the pleura surface. Both CADs are an upgrade of two methods previously presented as Voxel Based Neural Approach CAD . The novelty of this paper consists in the massive training using the public research Lung International Database Consortium (LIDC) database and on the implementation of new features for classification with respect to the original VBNA method. Finally, the proposed CAD is blindly validated on the ANODE09 dataset. The result of the validation is a score of 0.393, which corresponds to the average sensitivity of the CAD computed at seven predefined false positive rates: 1/8, 1/4, 1/2, 1, 2, 4, and 8 FP/CT.

  1. Autoantibody Signature Enhances the Positive Predictive Power of Computed Tomography and Nodule-Based Risk Models for Detection of Lung Cancer

    Science.gov (United States)

    Massion, Pierre P.; Healey, Graham F.; Peek, Laura J.; Fredericks, Lynn; Sewell, Herb F.; Murray, Andrea; Robertson, John F. R.

    2017-01-01

    Introduction The incidence of pulmonary nodules is increasing with the movement toward screening for lung cancer by low-dose computed tomography. Given the large number of benign nodules detected by computed tomography, an adjunctive test capable of distinguishing malignant from benign nodules would benefit practitioners. The ability of the EarlyCDT-Lung blood test (Oncimmune Ltd., Nottingham, United Kingdom) to make this distinction by measuring autoantibodies to seven tumor-associated antigens was evaluated in a prospective registry. Methods Of the members of a cohort of 1987 individuals with Health Insurance Portability and Accountability Act authorization, those with pulmonary nodules detected, imaging, and pathology reports were reviewed. All patients for whom a nodule was identified within 6 months of testing by EarlyCDT-Lung were included. The additivity of the test to nodule size and nodule-based risk models was explored. Results A total of 451 patients (32%) had at least one nodule, leading to 296 eligible patients after exclusions, with a lung cancer prevalence of 25%. In 4- to 20-mm nodules, a positive test result represented a greater than twofold increased relative risk for development of lung cancer as compared with a negative test result. Also, when the “both-positive rule” for combining binary tests was used, adding EarlyCDT-Lung to risk models improved diagnostic performance with high specificity (>92%) and positive predictive value (>70%). Conclusions A positive autoantibody test result reflects a significant increased risk for malignancy in lung nodules 4 to 20 mm in largest diameter. These data confirm that EarlyCDT-Lung may add value to the armamentarium of the practitioner in assessing the risk for malignancy in indeterminate pulmonary nodules. PMID:27615397

  2. Incidental lung nodules on CT examinations of the abdomen: Prevalence and reporting rates in the PACS era

    Energy Technology Data Exchange (ETDEWEB)

    Rinaldi, Maria Francesca [Radiologia III - Azienda Ospedaliera Pol. S.Orsola-Malpighi, via Massarenti 9 - 40138 Bologna (Italy); Bartalena, Tommaso, E-mail: t.bartalena@email.i [Radiologia III - Azienda Ospedaliera Pol. S.Orsola-Malpighi, via Massarenti 9 - 40138 Bologna (Italy); Giannelli, Giovanni; Rinaldi, Giovanni [Radiologia III - Azienda Ospedaliera Pol. S.Orsola-Malpighi, via Massarenti 9 - 40138 Bologna (Italy); Sverzellati, Nicola [Dipartimento di Scienze Cliniche, sezione di Radiologia - Universita di Parma, via Gramsci 14 - 43100 Parma (Italy); Canini, Romeo [Dipartimento Clinico di Scienze Radiologiche ed Istocitopatologiche, divisione di Diagnostica per Immagini - Universita di Bologna, via Massarenti 9 - 40138 Bologna (Italy); Gavelli, Giampaolo [Servizio di Diagnostica per Immagini, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (I.R.S.T.), via Piero Maroncelli, 40 - 47014 Meldola (Italy)

    2010-06-15

    Objectives: To retrospectively evaluate prevalence, reporting rates and clinical implications of incidental pulmonary nodules detected in multidetector computed tomography (MDCT) abdominal studies. Materials and methods: Abdominal MDCT studies of 243 consecutive patients, 94 of whom had a history of cancer, were evaluated. Lung bases included in the scan were reviewed on a PACS workstation with different window settings and post-processing techniques. Nodules were classified according to their density (calcified, solid noncalcified, non-solid, part-solid) and size (<4 mm; 4-6 mm; 6-8 mm; >8 mm). The study findings were compared with the corresponding radiologic reports. Previous of following CT studies, when available from the PACS, were also reviewed to evaluate changes in number and size of the detected nodules. Results: An average of 8.2 cm of lung parenchyma was imaged in each patient. 213 noncalcified nodules (NCNs) were identified in 95 patients (39.1%) but only 8 patients (8.4%) had it mentioned in the final report. Comparison CT studies were available for 44 out of the 95 positive patients showing disappearance of the nodules in 2 cases, no interval change in 26 and progression in size and/or number in 16 patients, in whom a final diagnosis of metastasis or primary lung cancers was achieved. Conclusion: Radiologists tend to overlook lung portions on abdominal CT studies. Underreporting may affect patient care and have medico-legal implications since images are permanently stored in digital format on PACS and CD-ROMs. Management of the discovered nodules should be tailored to the clinical situation of the patient, and particular care should be reserved to patients with oncologic history.

  3. New methods for using computer-aided detection information for the detection of lung nodules on chest radiographs

    NARCIS (Netherlands)

    Schalekamp, S.; Ginneken, B. van; Heggelman, B.; Imhof-Tas, M.W.; Somers, I.; Brink, M.; Spee, M.; Schaefer-Prokop, C.M.; Karssemeijer, N.

    2014-01-01

    Objective: To investigate two new methods of using computer-aided detection (CAD) system information for the detection of lung nodules on chest radiographs. We evaluated an interactive CAD application and an independent combination of radiologists and CAD scores. Methods: 300 posteroanterior and lat

  4. Small pulmonary nodules in baseline and incidence screening rounds of low-dose CT lung cancer screening

    NARCIS (Netherlands)

    Walter, Joan E; Heuvelmans, Marjolein A; Oudkerk, Matthijs

    Currently, lung cancer screening by low-dose computed tomography (LDCT) is widely recommended for high-risk individuals by US guidelines, but there still is an ongoing debate concerning respective recommendations for European countries. Nevertheless, the available data regarding pulmonary nodules

  5. Predicting lung cancer prior to surgical resection in patients with lung nodules.

    Science.gov (United States)

    Deppen, Stephen A; Blume, Jeffrey D; Aldrich, Melinda C; Fletcher, Sarah A; Massion, Pierre P; Walker, Ronald C; Chen, Heidi C; Speroff, Theodore; Degesys, Catherine A; Pinkerman, Rhonda; Lambright, Eric S; Nesbitt, Jonathan C; Putnam, Joe B; Grogan, Eric L

    2014-10-01

    Existing predictive models for lung cancer focus on improving screening or referral for biopsy in general medical populations. A predictive model calibrated for use during preoperative evaluation of suspicious lung lesions is needed to reduce unnecessary operations for a benign disease. A clinical prediction model (Thoracic Research Evaluation And Treatment [TREAT]) is proposed for this purpose. We developed and internally validated a clinical prediction model for lung cancer in a prospective cohort evaluated at our institution. Best statistical practices were used to construct, evaluate, and validate the logistic regression model in the presence of missing covariate data using bootstrap and optimism corrected techniques. The TREAT model was externally validated in a retrospectively collected Veteran Affairs population. The discrimination and calibration of the model was estimated and compared with the Mayo Clinic model in both the populations. The TREAT model was developed in 492 patients from Vanderbilt whose lung cancer prevalence was 72% and validated among 226 Veteran Affairs patients with a lung cancer prevalence of 93%. In the development cohort, the area under the receiver operating curve (AUC) and Brier score were 0.87 (95% confidence interval [CI], 0.83-0.92) and 0.12, respectively compared with the AUC 0.89 (95% CI, 0.79-0.98) and Brier score 0.13 in the validation dataset. The TREAT model had significantly higher accuracy (p < 0.001) and better calibration than the Mayo Clinic model (AUC = 0.80; 95% CI, 75-85; Brier score = 0.17). The validated TREAT model had better diagnostic accuracy than the Mayo Clinic model in preoperative assessment of suspicious lung lesions in a population being evaluated for lung resection.

  6. Influence of display quality on radiologists' performance in the detection of lung nodules on radiographs.

    Science.gov (United States)

    Buls, N; Shabana, W; Verbeek, P; Pevenage, P; De Mey, J

    2007-09-01

    The purpose of this study was to evaluate the influence of display quality on radiologists' performance in the detection of lung nodules. Display systems with various technical properties were considered based on their general availability in a radiology department. Their quality was assessed by physical tests. Multireader-multicase receiver operating characteristic (ROC) analysis was used to evaluate observer performance. The area under the curve (Az) was used as a metric for detectability of simulated lung nodules with diameters of 5 mm and 10 mm, and peak contrast values ranging from 0.1 (subtle) to 0.4 (evident) that were digitally superimposed on normal chest radiographs. Three experienced radiologists interpreted a batch of 60 radiographs on five different display systems; four monitors (two liquid crystal display (LCD) and two cathode ray tube (CRT) monitors) and one printed hardcopy. The physical tests showed superior performance of the two LCD monitors. ROC analysis resulted in the following Az scores: LCD-5MP Az = 0.78, hardcopy Az = 0.77, LCDc-2MP Az = 0.75, CRT-5MP Az = 0.72 and CRTc-1MP Az = 0.71. Difference in Az scores between the LCD-5MP monitor and both the CRT-5MP (p = 0.04) and CRTc-1MP (p = 0.01) monitors was significant. The primary class CRT-5MP monitor that showed reduced observer performance failed to comply with physical acceptance requirements. Luminance response was particularly observed to be insufficient. The results indicate that a quality assurance program has the potential to detect non-optimised display systems that could otherwise result in reduced observer performance.

  7. 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; Roy Choudhury, Kingshuk; Pezeshk, Aria; Sahiner, Berkman; Samei, Ehsan

    2017-08-22

    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 ([Formula: see text], [Formula: see text] and [Formula: see text] of the regional Hausdorff distance. Overall, there was a close concordance between the volumes of

  8. Lung cancer screening with CT: Evaluation of radiologists and different computer assisted detection software (CAD) as first and second readers for lung nodule detection at different dose levels

    Energy Technology Data Exchange (ETDEWEB)

    Christe, A., E-mail: andreas.christe@insel.ch [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland); Leidolt, L.; Huber, A.; Steiger, P. [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland); Szucs-Farkas, Z. [Radiology, Hospital Center of Biel (Switzerland); Roos, J.E. [Department of Radiology, Duke University, Durham, NC (United States); Heverhagen, J.T.; Ebner, L. [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland)

    2013-12-01

    Objectives: To find the best pairing of first and second reader at highest sensitivity for detecting lung nodules with CT at various dose levels. Materials and methods: An anthropomorphic lung phantom and artificial lung nodules were used to simulate screening CT-examination at standard dose (100 mAs, 120 kVp) and 8 different low dose levels, using 120, 100 and 80 kVp combined with 100, 50 and 25 mAs. At each dose level 40 phantoms were randomly filled with 75 solid and 25 ground glass nodules (5–12 mm). Two radiologists and 3 different computer aided detection softwares (CAD) were paired to find the highest sensitivity. Results: Sensitivities at standard dose were 92%, 90%, 84%, 79% and 73% for reader 1, 2, CAD1, CAD2, CAD3, respectively. Combined sensitivity for human readers 1 and 2 improved to 97%, (p1 = 0.063, p2 = 0.016). Highest sensitivities – between 97% and 99.0% – were achieved by combining any radiologist with any CAD at any dose level. Combining any two CADs, sensitivities between 85% and 88% were significantly lower than for radiologists combined with CAD (p < 0.03). Conclusions: Combination of a human observer with any of the tested CAD systems provide optimal sensitivity for lung nodule detection even at reduced dose at 25 mAs/80 kVp.

  9. Initial experience of percutaneous transthoracic needle biopsy of lung nodules using C-arm cone-beam CT systems

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam; Goo, Jin Mo; Lee, Hyun Ju; Lee, Youkyung; Kim, Jung Im; Choi, So Young; Kim, Hyo-Cheol [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea); Park, Chang Min [Seoul National University Hospital, Department of Radiology, Seoul (Korea); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea)

    2010-09-15

    To describe our initial experience with percutaneous transthoracic biopsy (PCNB) of lung nodules using C-arm cone-beam CT (CBCT). Seventy-one consecutive patients with lung nodules of 30 mm or smaller underwent CBCT-guided PCNB using a coaxial cutting needle. We evaluated the procedure time, coaxial introducer dwell time, the numbers of pleural passages, coaxial introducer repositionings and CT acquisitions, as well as the technical success rate and radiation doses. Diagnostic accuracy, sensitivity, specificity and incidence of complications were also evaluated. PCNB was performed for 71 nodules: 63 solid, 6 part-solid and 2 ground-glass nodules. The procedure time, coaxial introducer dwell time, numbers of pleural passages, coaxial introducer repositionings and CT acquisitions were 17.9 {+-} 5.9 min, 8.7 {+-} 3.8 min, 1.1 {+-} 0.4, 0.2 {+-} 0.5 and 2.9 {+-} 0.7, respectively. The technical success rate was 100% and the radiation dose was 272 {+-} 116 mGy. Thirty-six nodules (50.7%) were diagnosed as malignant, 25 (35.2%) as benign and 10 (14.1%) as indeterminate. Diagnostic accuracy, sensitivity, specificity and incidence of complications were 98.4%, 97%, 100% and 38%, respectively. Complications included pneumothorax in 18 patients (25.4%), haemoptysis in 10 (14.1%) and chest pain in one (1.4%). Under CBCT guidance, PCNB of lung nodules can be performed accurately, providing both real-time fluoroscopic guidance and CT imaging capabilities. (orig.)

  10. Comparison of cone-beam CT-guided and CT fluoroscopy-guided transthoracic needle biopsy of lung nodules

    Energy Technology Data Exchange (ETDEWEB)

    Rotolo, Nicola; Imperatori, Andrea; Arlant, Veronica; Dominioni, Lorenzo [Insubria University, Center for Thoracic Surgery, Varese (Italy); Floridi, Chiara; Fontana, Federico; Ierardi, Anna Maria; Mangini, Monica; De Marchi, Giuseppe; Fugazzola, Carlo; Carrafiello, Gianpaolo [Insubria University, Radiology Department, Varese (Italy); Novario, Raffaele [Insubria University, Medical Physics Department, Varese (Italy)

    2016-02-15

    To compare the diagnostic performance of cone-beam CT (CBCT)-guided and CT fluoroscopy (fluoro-CT)-guided technique for transthoracic needle biopsy (TNB) of lung nodules. The hospital records of 319 consecutive patients undergoing 324 TNBs of lung nodules in a single radiology unit in 2009-2013 were retrospectively evaluated. The newly introduced CBCT technology was used to biopsy 123 nodules; 201 nodules were biopsied by conventional fluoro-CT-guided technique. We assessed the performance of the two biopsy systems for diagnosis of malignancy and the radiation exposure. Nodules biopsied by CBCT-guided and by fluoro-CT-guided technique had similar characteristics: size, 20 ± 6.5 mm (mean ± standard deviation) vs. 20 ± 6.8 mm (p = 0.845); depth from pleura, 15 ± 15 mm vs. 15 ± 16 mm (p = 0.595); malignant, 60 % vs. 66 % (p = 0.378). After a learning period, the newly introduced CBCT-guided biopsy system and the conventional fluoro-CT-guided system showed similar sensitivity (95 % and 92 %), specificity (100 % and 100 %), accuracy for diagnosis of malignancy (96 % and 94 %), and delivered non-significantly different median effective doses [11.1 mSv (95 % CI 8.9-16.0) vs. 14.5 mSv (95 % CI 9.5-18.1); p = 0.330]. The CBCT-guided and fluoro-CT-guided systems for lung nodule biopsy are similar in terms of diagnostic performance and effective dose, and may be alternatively used to optimize the available technological resources. (orig.)

  11. 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

  12. A virtual clinical trial using projection-based nodule insertion to determine radiologist reader performance in lung cancer screening CT

    Science.gov (United States)

    Yu, Lifeng; Hu, Qiyuan; Koo, Chi Wan; Takahashi, Edwin A.; Levin, David L.; Johnson, Tucker F.; Hora, Megan J.; Dirks, Shane; Chen, Baiyu; McMillan, Kyle; Leng, Shuai; Fletcher, J. G.; McCollough, Cynthia H.

    2017-03-01

    Task-based image quality assessment using model observers is promising to provide an efficient, quantitative, and objective approach to CT dose optimization. Before this approach can be reliably used in practice, its correlation with radiologist performance for the same clinical task needs to be established. Determining human observer performance for a well-defined clinical task, however, has always been a challenge due to the tremendous amount of efforts needed to collect a large number of positive cases. To overcome this challenge, we developed an accurate projection-based insertion technique. In this study, we present a virtual clinical trial using this tool and a low-dose simulation tool to determine radiologist performance on lung-nodule detection as a function of radiation dose, nodule type, nodule size, and reconstruction methods. The lesion insertion and low-dose simulation tools together were demonstrated to provide flexibility to generate realistically-appearing clinical cases under well-defined conditions. The reader performance data obtained in this virtual clinical trial can be used as the basis to develop model observers for lung nodule detection, as well as for dose and protocol optimization in lung cancer screening CT.

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

    OpenAIRE

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

    2008-01-01

    Objective 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. Materials and Methods 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 lu...

  14. 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

  15. 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

  16. 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.

  17. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    Background US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and thei

  18. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and the

  19. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M A; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem P Th M; Groen, Harry J M; de Koning, Harry J.; Oudkerk, Matthijs

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and

  20. 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 m

  1. Detection of lung nodules. New opportunities in chest radiography; Detektion pulmonaler Rundherde. Neue Moeglichkeiten der Thoraxradiographie

    Energy Technology Data Exchange (ETDEWEB)

    Poetter-Lang, S. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Department of Biomedical Imaging and Image-Guided Therapy, Wien (Austria); Schalekamp, S. [Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Schaefer-Prokop, C. [Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Meander Medical Center Amersfoort, Amersfoort (Netherlands); Uffmann, M. [Landesklinikum Neunkirchen, Abteilung fuer Radiodiagnostik, Neunkirchen (Germany)

    2014-05-15

    Chest radiography still represents the most commonly performed X-ray examination because it is readily available, requires low radiation doses and is relatively inexpensive. However, as previously published, many initially undetected lung nodules are retrospectively visible in chest radiographs. The great improvements in detector technology with the increasing dose efficiency and improved contrast resolution provide a better image quality and reduced dose needs. The dual energy acquisition technique and advanced image processing methods (e.g. digital bone subtraction and temporal subtraction) reduce the anatomical background noise by reduction of overlapping structures in chest radiography. Computer-aided detection (CAD) schemes increase the awareness of radiologists for suspicious areas. The advanced image processing methods show clear improvements for the detection of pulmonary lung nodules in chest radiography and strengthen the role of this method in comparison to 3D acquisition techniques, such as computed tomography (CT). Many of these methods will probably be integrated into standard clinical treatment in the near future. Digital software solutions offer advantages as they can be easily incorporated into radiology departments and are often more affordable as compared to hardware solutions. (orig.) [German] Das Thoraxroentgen mit den Vorteilen der schnellen Verfuegbarkeit, geringen Strahlendosis und geringen Kosten ist unveraendert die haeufigste radiologische Untersuchung. Es wurde jedoch vielfach publiziert, dass primaer im Thoraxroentgen uebersehene Lungenrundherde retrospektiv sichtbar waren. Die grossen Fortschritte der Detektortechnologie mit verbesserter Dosiseffizienz und Ortsaufloesung der Systeme fuehren zu einer gesteigerten Bildqualitaet bei geringerem Dosisbedarf. Die Dual-energy-Aufnahmetechnik sowie auch Bildverarbeitungsmethoden wie die digitale Knochensubtraktion und die ''temporal subtraction'' reduzieren das &apos

  2. Dual-energy snap-shot perfusion CT in suspect pulmonary nodules and masses and for lung cancer staging.

    Science.gov (United States)

    Sudarski, Sonja; Hagelstein, Claudia; Weis, Meike; Schoenberg, Stefan O; Apfaltrer, Paul

    2015-12-01

    Dual energy computed tomography (DECT) has proven its clinical usefulness for improved tissue characterization within the past years. In thoracic oncology, DECT can be used to differentiate between benign and malignant pulmonary nodules and masses. In patients with known lung cancer, DECT can add incremental functional information to staging scans, therapeutic response evaluation, as well as to the assessment of lung function. This review aims to give an overview on the current clinical utilities of DECT of the chest, its multiple post-processing applications and dose saving options. Furthermore, this review highlights promising applications of DECT that merit implementation in future clinical routine.

  3. Volumetric analysis of lung nodules in computed tomography (CT): comparison of two different segmentation algorithm softwares and two different reconstruction filters on automated volume calculation.

    Science.gov (United States)

    Christe, Andreas; Brönnimann, Alain; Vock, Peter

    2014-02-01

    A precise detection of volume change allows for better estimating the biological behavior of the lung nodules. Postprocessing tools with automated detection, segmentation, and volumetric analysis of lung nodules may expedite radiological processes and give additional confidence to the radiologists. To compare two different postprocessing software algorithms (LMS Lung, Median Technologies; LungCARE®, Siemens) in CT volumetric measurement and to analyze the effect of soft (B30) and hard reconstruction filter (B70) on automated volume measurement. Between January 2010 and April 2010, 45 patients with a total of 113 pulmonary nodules were included. The CT exam was performed on a 64-row multidetector CT scanner (Somatom Sensation, Siemens, Erlangen, Germany) with the following parameters: collimation, 24x1.2 mm; pitch, 1.15; voltage, 120 kVp; reference tube current-time, 100 mAs. Automated volumetric measurement of each lung nodule was performed with the two different postprocessing algorithms based on two reconstruction filters (B30 and B70). The average relative volume measurement difference (VME%) and the limits of agreement between two methods were used for comparison. At soft reconstruction filters the LMS system produced mean nodule volumes that were 34.1% (P filters (B30) was significantly larger than with hard filters (B70); 11.2% for LMS and 1.6% for LungCARE®, respectively (both with P filters, 13.6% for soft and 3.8% for hard filters, respectively (P  0.05). There is a substantial inter-software (LMS/LungCARE®) as well as intra-software variability (B30/B70) in lung nodule volume measurement; therefore, it is mandatory to use the same equipment with the same reconstruction filter for the follow-up of lung nodule volume.

  4. 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.

  5. A feasibility study of automatic lung nodule detection in chest digital tomosynthesis with machine learning based on support vector machine

    Science.gov (United States)

    Lee, Donghoon; Kim, Ye-seul; Choi, Sunghoon; Lee, Haenghwa; Jo, Byungdu; Choi, Seungyeon; Shin, Jungwook; Kim, Hee-Joung

    2017-03-01

    The chest digital tomosynthesis(CDT) is recently developed medical device that has several advantage for diagnosing lung disease. For example, CDT provides depth information with relatively low radiation dose compared to computed tomography (CT). However, a major problem with CDT is the image artifacts associated with data incompleteness resulting from limited angle data acquisition in CDT geometry. For this reason, the sensitivity of lung disease was not clear compared to CT. In this study, to improve sensitivity of lung disease detection in CDT, we developed computer aided diagnosis (CAD) systems based on machine learning. For design CAD systems, we used 100 cases of lung nodules cropped images and 100 cases of normal lesion cropped images acquired by lung man phantoms and proto type CDT. We used machine learning techniques based on support vector machine and Gabor filter. The Gabor filter was used for extracting characteristics of lung nodules and we compared performance of feature extraction of Gabor filter with various scale and orientation parameters. We used 3, 4, 5 scales and 4, 6, 8 orientations. After extracting features, support vector machine (SVM) was used for classifying feature of lesions. The linear, polynomial and Gaussian kernels of SVM were compared to decide the best SVM conditions for CDT reconstruction images. The results of CAD system with machine learning showed the capability of automatically lung lesion detection. Furthermore detection performance was the best when Gabor filter with 5 scale and 8 orientation and SVM with Gaussian kernel were used. In conclusion, our suggested CAD system showed improving sensitivity of lung lesion detection in CDT and decide Gabor filter and SVM conditions to achieve higher detection performance of our developed CAD system for CDT.

  6. 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.)

  7. Development of local complexity metrics to quantify the effect of anatomical noise on detectability of lung nodules in chest CT imaging

    Science.gov (United States)

    Solomon, Justin; Rubin, Geoffrey; Smith, Taylor; Harrawood, Brian; Choudhury, Kingshuk Roy; Samei, Ehsan

    2017-03-01

    The purpose of this study was to develop metrics of local anatomical complexity and compare them with detectability of lung nodules in CT. Data were drawn retrospectively from a published perception experiment in which detectability was assessed in cases enriched with virtual nodules (13 radiologists x 157 total nodules = 2041 responses). A local anatomical complexity metric called the distractor index was developed, defined as the Gaussian weighted proportion (i.e., average) of distracting local voxels (50 voxels in-plane, 5 slices). A distracting voxel was classified by thresholding image data that had been selectively filtered to enhance nodule-like features. The distractor index was measured for each nodule location in the nodule-free images. The local pixel standard deviation (STD) was also measured for each nodule. Other confounding factors of search fraction (proportion of lung voxels to total voxels in the given slice) and peripheral distance (defined as the 3D distance of the nodule from the trachea bifurcation) were measured. A generalized linear mixed-effects statistical model (no interaction terms, probit link function, random reader term) was fit to the data to determine the influence of each metric on detectability. In order of decreasing effect size: distractor index, STD, and search fraction all significantly affected detectability (P < 0.001). Distance to the trachea did not have a significant effect (P < 0.05). These data demonstrate that local lung complexity degrades detection of lung nodules and the distractor index could serve as a good surrogate metric to quantify anatomical complexity.

  8. MORPHOLOGICAL CHARACTERISTICS OF POTENTIALLY MALIGNANT PULMONARY NODULES IN HIGH-RISK MALE SMOKERS DETECTED IN LUNG CANCER SCREENING TRIAL IN CRACOW, POLAND

    NARCIS (Netherlands)

    Kiszka, Kinga; Rudnicka-Sosin, Lucyna; Tomaszewska, Romana; Urbanczyk-Zawadzka, Malgorzata; Krupinski, Maciej; Pikul, Patrycja; Podsiadlo, Kaja; Pasowicz, Mieczyslaw; Vliegenthart, Rozemarijn; Oudkerk, Matthijs; Miszalski-Jamka, Tomasz

    2013-01-01

    The purpose of this paper was to present morphological characteristics of potentially malignant nodules revealed in a group of male smokers aged 50-74 with a very high risk for developing lung cancer estimated in the study for lung cancer screening in Cracow (Poland). Nine hundred male smokers aged

  9. Lung adenocarcinoma as a solitary pulmonary nodule: prognostic determinants of CT, PET, and histopathologic findings.

    Science.gov (United States)

    Lee, Ho Yun; Han, Joungho; Lee, Kyung Soo; Koo, Ji Hyun; Jeong, Sun Young; Kim, Byung-Tae; Cho, Young-Seok; Shim, Young Mog; Kim, Jhingook; Kim, Kwanmien; Choi, Yong Soo

    2009-12-01

    We aimed to retrospectively compare CT, PET, and histopathologic (the extent of bronchioloalveolar carcinoma [BAC] components) findings of solitary pulmonary nodular (SPN) adenocarcinomas of the lung to determine their value as prognostic determinants. We reviewed CT and PET characteristics of tumors and pathologic specimens from 65 consecutive patients who underwent surgical resection for SPN adenocarcinomas. Nodule size and TDR (tumor shadow disappearance rate) were assessed from CT scans, and maximum standardized uptake value (SUVmax) of tumors was measured at PET. On pathologic examination, BAC, non-BAC, and central fibrous scar ratios were quantified. Prognosis was evaluated by noting disease recurrence during a minimum 12-month follow-up period after curative resection. The interrelationships between TDR, SUVmax, BAC, and non-BAC ratio were studied, and relationships between recurrence and various variables were analyzed. The median follow-up time was 33 months, and seven patients (11%) developed disease recurrence after surgical resection. TDR at CT and SUVmax at PET correlated well with pathologic BAC and non-BAC ratios. Between subgroups with and without recurrence, there were significant differences in SUVmax and BAC and non-BAC ratios. Based on univariate survival analyses, pathologic BAC and non-BAC ratios were risk factors significantly related to recurrence, but only high non-BAC ratio remained as an independent factor associated with recurrence in the multivariate analysis (hazard ratio [HR]=0.956, P=0.013). Among the factors examined, pathologic non-BAC ratio is the only independent risk factor for poor prognosis in patients with SPN adenocarcinomas.

  10. [Localizating and Extracting Small Peripheral Nodules of Lung with Simulating 
Radiaotherapy Combining Methylene Blue Staining].

    Science.gov (United States)

    Mao, Feng; Zhang, Liang; Gu, Hengle; Zhang, Hui; Lv, Changxing; Shen-Tu, Yang

    2016-09-20

    With the extensively application of HRCT (high resolution CT) and the popularization of early lung cancer screening, the proportion of small nodullar lung cancer to be operated increases rapidly. Identifying the focus lesions quickly and accurately in operation has shown to be a challenge. We carried out this research trying to make use of and evaluate a new method that localizaes and extracts small peripheral pulmonary nodules by way of simulating radiaotherapy combining methylene blue staining. From February 2012 to January 2015, 97 patients with 100 peripheral pulmonary nodules ≤10 mm in size were simulated puncturing using a radiotherapy planning. When the anaesthesia came into use, methylene blue dye was injected to the virtually identified point corresponding to the surface point, according to the angle and depth previously computed by the radiotherapy planning. The video-assisted thoracoscopic surgery (VATS) wedge resections of the marked lesions were undertaken and the specimens were sent for frozen pathologic examination. The interval time from anesthesia-completing to puncture and injection, The interval time from methylene blue injection to identifying the stained area and the distances between the centre point of the stains and edge of coloured lesion were recorded. Our preoperative localization procedure was successful in 96 of 100 (96%) nodules. The interval time from anesthesia-completing to puncture and injection of methylene blue were (4.85±1.25) min. The interval time from methylene blue injection to identifying the stained area was (16.36±2.36) min. The distances between the centre point of the stains and edge of coloured lesion were (4.78±2.51) mm. No complication was observed in all participants. The new method of locating peripheral pulmonary nodules by simulating simulating radiaotherapy combining methylene blue staining has a high success rate and no complication for localizing small peripheral pulmonary lesions, avoiding the fear and

  11. Assessing nodule detection on lung cancer screening CT: the effects of tube current modulation and model observer selection on detectability maps

    Science.gov (United States)

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

    2016-03-01

    Lung cancer screening using low dose CT has been shown to reduce lung cancer related mortality and been approved for widespread use in the US. These scans keep radiation doses low while maximizing the detection of suspicious lung lesions. Tube current modulation (TCM) is one technique used to optimize dose, however limited work has been done to assess TCM's effect on detection tasks. In this work the effect of TCM on detection is investigated throughout the lung utilizing several different model observers (MO). 131 lung nodules were simulated at 1mm intervals in each lung of the XCAT phantom. A Sensation 64 TCM profile was generated for the XCAT phantom and 2500 noise realizations were created using both TCM and a fixed TC. All nodules and noise realizations were reconstructed for a total of 262 (left and right lungs) nodule reconstructions and 10 000 XCAT lung reconstructions. Single-slice Hotelling (HO) and channelized Hotelling (CHO) observers, as well as a multislice CHO were used to assess area-under-the-curve (AUC) as a function of nodule location in both the fixed TC and TCM cases. As expected with fixed TC, nodule detectability was lowest through the shoulders and leveled off below mid-lung; with TCM, detectability was unexpectedly highest through the shoulders, dropping sharply near the mid-lung and then increasing into the abdomen. Trends were the same for all model observers. These results suggest that TCM could be further optimized for detection and that detectability maps present exciting new opportunities for TCM optimization on a patient-specific level.

  12. Effects of Iterative Reconstruction Algorithms on Computer-assisted Detection (CAD) Software for Lung Nodules in Ultra-low-dose CT for Lung Cancer Screening.

    Science.gov (United States)

    Nomura, Yukihiro; Higaki, Toru; Fujita, Masayo; Miki, Soichiro; Awaya, Yoshikazu; Nakanishi, Toshio; Yoshikawa, Takeharu; Hayashi, Naoto; Awai, Kazuo

    2017-02-01

    This study aimed to evaluate the effects of iterative reconstruction (IR) algorithms on computer-assisted detection (CAD) software for lung nodules in ultra-low-dose computed tomography (ULD-CT) for lung cancer screening. We selected 85 subjects who underwent both a low-dose CT (LD-CT) scan and an additional ULD-CT scan in our lung cancer screening program for high-risk populations. The LD-CT scans were reconstructed with filtered back projection (FBP; LD-FBP). The ULD-CT scans were reconstructed with FBP (ULD-FBP), adaptive iterative dose reduction 3D (AIDR 3D; ULD-AIDR 3D), and forward projected model-based IR solution (FIRST; ULD-FIRST). CAD software for lung nodules was applied to each image dataset, and the performance of the CAD software was compared among the different IR algorithms. The mean volume CT dose indexes were 3.02 mGy (LD-CT) and 0.30 mGy (ULD-CT). For overall nodules, the sensitivities of CAD software at 3.0 false positives per case were 78.7% (LD-FBP), 9.3% (ULD-FBP), 69.4% (ULD-AIDR 3D), and 77.8% (ULD-FIRST). Statistical analysis showed that the sensitivities of ULD-AIDR 3D and ULD-FIRST were significantly higher than that of ULD-FBP (P CAD software in ULD-CT was improved by using IR algorithms. In particular, the performance of CAD in ULD-FIRST was almost equivalent to that in LD-FBP. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  13. Computer-aided diagnosis: a 3D segmentation method for lung nodules in CT images by use of a spiral-scanning technique

    Science.gov (United States)

    Wang, Jiahui; Engelmann, Roger; Li, Qiang

    2008-03-01

    Lung nodule segmentation in computed tomography (CT) plays an important role in computer-aided detection, diagnosis, and quantification systems for lung cancer. In this study, we developed a simple but accurate nodule segmentation method in three-dimensional (3D) CT. First, a volume of interest (VOI) was determined at the location of a nodule. We then transformed the VOI into a two-dimensional (2D) image by use of a "spiral-scanning" technique, in which a radial line originating from the center of the VOI spirally scanned the VOI. The voxels scanned by the radial line were arranged sequentially to form a transformed 2D image. Because the surface of a nodule in 3D image became a curve in the transformed 2D image, the spiral-scanning technique considerably simplified our segmentation method and enabled us to obtain accurate segmentation results. We employed a dynamic programming technique to delineate the "optimal" outline of a nodule in the 2D image, which was transformed back into the 3D image space to provide the interior of the nodule. The proposed segmentation method was trained on the first and was tested on the second Lung Image Database Consortium (LIDC) datasets. An overlap between nodule regions provided by computer and by the radiologists was employed as a performance metric. The experimental results on the LIDC database demonstrated that our segmentation method provided relatively robust and accurate segmentation results with mean overlap values of 66% and 64% for the nodules in the first and second LIDC datasets, respectively, and would be useful for the quantification, detection, and diagnosis of lung cancer.

  14. From diagnosis to therapy in lung cancer: management of CT detected pulmonary nodules, a summary of the 2015 Chinese-German Lung Cancer Expert Panel.

    Science.gov (United States)

    Su, Chunxia; Meyer, Mathias; Pirker, Robert; Voigt, Wieland; Shi, Jingyun; Pilz, Lothar; Huber, Rudolf M; Wu, Yilong; Wang, Jinghong; He, Yonglan; Wang, Xuan; Zhang, Jian; Zhi, Xiuyi; Shi, Meiqi; Zhu, Bo; Schoenberg, Stefan S; Henzler, Thomas; Manegold, Christian; Zhou, Caicun; Roessner, Eric Dominic

    2016-08-01

    The first Chinese-German Lung Cancer Expert Panel was held in November 2015 one day after the 7th Chinese-German Lung Cancer Forum, Shanghai. The intention of the meeting was to discuss strategies for the diagnosis and treatment of lung cancer within the context of lung cancer screening. Improved risk classification criteria and novel imaging approaches for screening populations are highly required as more than half of lung cancer cases are false positive during the initial screening round if the National Lung Screening Trial (NLST) demographic criteria [≥30 pack years (PY) of cigarettes, age ≥55 years] are applied. Moreover, if the NLST criteria are applied to the Chinese population a high number of lung cancer patients are not diagnosed due to non-smoking related risk factors in China. The primary goal in the evaluation of pulmonary nodules (PN) is to determine whether they are malignant or benign. Volumetric based screening concepts such as investigated in the Dutch-Belgian randomized lung cancer screening trial (NELSON) seem to achieve higher specificity. Chest CT is the best imaging technique to identify the origin and location of the nodule since 20% of suspected PN found on chest X-ray turn out to be non-pulmonary lesions. Moreover, novel state-of-the-art CT systems can reduce the radiation dose for lung cancer screening acquisitions down to a level of 0.1 mSv with improved image quality to novel reconstruction techniques and thus reduce concerns related to chest CT as the primary screening technology. The aim of the first part of this manuscript was to summarize the current status of novel diagnostic techniques used for lung cancer screening and minimally invasive treatment techniques for progressive PNs that were discussed during the first Chinese-German Lung Cancer. This part should serve as an educational part for the readership of the techniques that were discussed during the Expert Panel. The second part summarizes the consensus recommendations

  15. [Comparison of LCD and CRT monitors for detection of pulmonary nodules and interstitial lung diseases on digital chest radiographs by using receiver operating characteristic analysis].

    Science.gov (United States)

    Ikeda, Ryuji; Katsuragawa, Shigehiko; Shimonobou, Toshiaki; Hiai, Yasuhiro; Hashida, Masahiro; Awai, Kazuo; Yamashita, Yasuyuki; Doi, Kunio

    2006-05-20

    Soft copy reading of digital images has been practiced commonly in the PACS environment. In this study, we compared liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors for detection of pulmonary nodules and interstitial lung diseases on digital chest radiographs by using receiver operating characteristic (ROC) analysis. Digital chest images with a 1000x1000 matrix size and a 8 bit grayscale were displayed on LCD/CRT monitor with 2M pixels in each observer test. Eight and ten radiologists participated in the observer tests for detection of nodules and interstitial diseases, respectively. In each observer test, radiologists marked their confidence levels for diagnosis of pulmonary nodules or interstitial diseases. The detection performance of radiologists was evaluated by ROC analyses. The average Az values (area under the ROC curve) in detecting pulmonary nodules with LCD and CRT monitors were 0.792 and 0.814, respectively. In addition, the average Az values in detecting interstitial diseases with LCD and CRT monitors were 0.951 and 0.953, respectively. There was no statistically significant difference between LCD and CRT for both detection of pulmonary nodules (P=0.522) and interstitial lung diseases (P=0.869). Therefore, we believe that the LCD monitor instead of the CRT monitor can be used for the diagnosis of pulmonary nodules and interstitial lung diseases in digital chest images.

  16. Granulomatous bronchiolitis with necrobiotic pulmonary nodules in Crohn's disease.

    Science.gov (United States)

    Freeman, Hugh J; Davis, Jennifer E; Prest, Marcia E; Lawson, Edward J

    2004-11-01

    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.

  17. 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.

  18. Radiomics of Lung Nodules: A Multi-Institutional Study of Robustness and Agreement of Quantitative Imaging Features

    Science.gov (United States)

    Kalpathy-Cramer, Jayashree; Mamomov, Artem; Zhao, Binsheng; Lu, Lin; Cherezov, Dmitry; Napel, Sandy; Echegaray, Sebastian; Rubin, Daniel; McNitt-Gray, Michael; Lo, Pechin; Sieren, Jessica C.; Uthoff, Johanna; Dilger, Samantha K. N.; Driscoll, Brandan; Yeung, Ivan; Hadjiiski, Lubomir; Cha, Kenny; Balagurunathan, Yoganand; Gillies, Robert; Goldgof, Dmitry

    2017-01-01

    Radiomics is to provide quantitative descriptors of normal and abnormal tissues during classification and prediction tasks in radiology and oncology. Quantitative Imaging Network members are developing radiomic “feature” sets to characterize tumors, in general, the size, shape, texture, intensity, margin, and other aspects of the imaging features of nodules and lesions. Efforts are ongoing for developing an ontology to describe radiomic features for lung nodules, with the main classes consisting of size, local and global shape descriptors, margin, intensity, and texture-based features, which are based on wavelets, Laplacian of Gaussians, Law’s features, gray-level co-occurrence matrices, and run-length features. The purpose of this study is to investigate the sensitivity of quantitative descriptors of pulmonary nodules to segmentations and to illustrate comparisons across different feature types and features computed by different implementations of feature extraction algorithms. We calculated the concordance correlation coefficients of the features as a measure of their stability with the underlying segmentation; 68% of the 830 features in this study had a concordance CC of ≥0.75. Pairwise correlation coefficients between pairs of features were used to uncover associations between features, particularly as measured by different participants. A graphical model approach was used to enumerate the number of uncorrelated feature groups at given thresholds of correlation. At a threshold of 0.75 and 0.95, there were 75 and 246 subgroups, respectively, providing a measure for the features’ redundancy. PMID:28149958

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

    Energy Technology Data Exchange (ETDEWEB)

    Ozekes, Serhat; Osman, Onur; Ucan, N. [Istanbul Commerce University, Ragip Gumuspala Cad. No: 84 34378 Eminonu, Istanbul (Turkmenistan)

    2008-02-15

    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.

  20. 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

  1. 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

    NARCIS (Netherlands)

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

    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

  2. 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.

    NARCIS (Netherlands)

    Hoop, B. de; Gietema, H.; Ginneken, B. van; Zanen, P.; Groenewegen, G.; Prokop, M.

    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

  3. 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.

  4. [Quality assurance of rapid on-site evaluation of CT-guided fine-needle aspiration cytology of lung nodules].

    Science.gov (United States)

    Bak, Mihály; Hidvégi, Judit; Andi, Judit; Bahéry, Mária; Kovács, Eszter; Schneider, Ferenc; Kostic, Szilárd; Rényi-Vámos, Ferenc; Szőke, János; Nyári, Tibor; Gődény, Mária; Kásler, Miklós

    2013-01-06

    The methods available for the diagnosis of lung cancer include radiologic, cytologic and pathologic procedures. The aim of this study was to determine the quality assurance of CT guided fine needle aspiration cytology of lung nodules. Cytology results were rated to 4 categories (positive; suspicious; negative; not representative). All cytology reports were compared with the final histology diagnosis. A total of 128 patients underwent CT-guided percutaneous fine-needle aspiration biopsy cytology (63 males; 65 females; mean age 62.8 years). Smears were adequate in 99 cases and inadequate in 29 cases. The average diameter of the nodules was 3.28 cm. Thirty three (25.6%) of the cases were histologically verified and 2 falsely negative and 2 falsely positive cases were detected. The sensitivity and the positive predictive value were 88.8% and 88.8%, respectively. Pneumothorax developed in 7 (5.4%) cases. These results suggest that CT-guided transthoracic fine needle aspiration cytology has a high diagnostic accuracy and an acceptable complication rate. The auditing valves of the results meet the proposed threshold values.

  5. Granulomatous PJP presenting as a solitary lung nodule in an immune competent female.

    Science.gov (United States)

    Lam, J; Kelly, M M; Leigh, R; Parkins, M D

    2014-01-01

    Pneumocystis jiroveci pneumonia (PJP) opportunistically targets immunosuppressed patients, most notably those with advanced HIV/AIDS. Radiologically, PJP typically appears as bilateral diffuse pulmonary infiltrates. Herein an unusual case of an immunocompetent woman developing granulomatous PJP in the absence of evident risk factors is described. PJP may be an under-recognized cause of pulmonary nodules in immune competent individuals.

  6. Granulomatous PJP presenting as a solitary lung nodule in an immune competent female

    Directory of Open Access Journals (Sweden)

    J. Lam

    2014-01-01

    Full Text Available Pneumocystis jiroveci pneumonia (PJP opportunistically targets immunosuppressed patients, most notably those with advanced HIV/AIDS. Radiologically, PJP typically appears as bilateral diffuse pulmonary infiltrates. Herein an unusual case of an immunocompetent woman developing granulomatous PJP in the absence of evident risk factors is described. PJP may be an under-recognized cause of pulmonary nodules in immune competent individuals.

  7. Localizating and Extracting Small Peripheral Nodules of Lung with Simulating 
Radiaotherapy Combining Methylene Blue Staining

    Directory of Open Access Journals (Sweden)

    Feng MAO

    2016-09-01

    Full Text Available Background and objective With the extensively application of HRCT (high resolution CT and the popularization of early lung cancer screening, the proportion of small nodullar lung cancer to be operated increases rapidly. Identifying the focus lesions quickly and accurately in operation has shown to be a challenge. We carried out this research trying to make use of and evaluate a new method that localizaes and extracts small peripheral pulmonary nodules by way of simulating radiaotherapy combining methylene blue staining. Methods From February 2012 to January 2015, 97 patients with 100 peripheral pulmonary nodules ≤10 mm in size were simulated puncturing using a radiotherapy planning. When the anaesthesia came into use, methylene blue dye was injected to the virtually identified point corresponding to the surface point, according to the angle and depth previously computed by the radiotherapy planning. The video-assisted thoracoscopic surgery (VATS wedge resections of the marked lesions were undertaken and the specimens were sent for frozen pathologic examination. The interval time from anesthesia-completing to puncture and injection, The interval time from methylene blue injection to identifying the stained area and the distances between the centre point of the stains and edge of coloured lesion were recorded. Results Our preoperative localization procedure was successful in 96 of 100 (96% nodules. The interval time from anesthesia-completing to puncture and injection of methylene blue were (4.85±1.25 min. The interval time from methylene blue injection to identifying the stained area was (16.36±2.36 min. The distances between the centre point of the stains and edge of coloured lesion were (4.78±2.51 mm. No complication was observed in all participants. Conclusion The new method of locating peripheral pulmonary nodules by simulating simulating radiaotherapy combining methylene blue staining has a high success rate and no complication for

  8. 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.

  9. 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.

  10. 'Bubble-like' lung metastases in osteosarcoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Briccoli, Antonio; Rocca, Michele; Salone, Maria Cristina [General Surgery, Rizzoli Orthopaedic Institute, Bologna (Italy); Di Fiore, Maria [Anaesthesiology, izzoli Orthopaedic Institute, Bologna (Italy); Vanel, Daniel [Research in Imaging, Rizzoli Orthopaedic Institute, Bologna (Italy)], E-mail: vanel@igr.fr; Balladelli, Alba [Laboratory Oncology Research, Rizzoli Orthopaedic Institute, Bologna (Italy); Alberghini, Marco [Pathology, Rizzoli Orthopaedic Institute, Bologna (Italy)

    2009-07-15

    Purpose: Cavitation of pulmonary metastases have been reported by several authors either as a spontaneous phenomenon or as a consequence of chemotherapy. We present two cases, with this type of image in follow-up, and 20-45 months after the end of treatment. This was the first sign of pulmonary metastases. Results: Two patients with osteogenic sarcoma developed radiological evidence of pulmonary 'bubble-like' cavitation several years following completion of chemotherapy. In one patient the 'bubble-like' cavitation transformed into a solid nodule. Both patients had surgical resections of all pulmonary lesions, and histology confirmed presence of viable osteosarcoma metastases. Conclusion: The two cases suggest that onset of 'bubble-like' cavitation in lung parenchyma of osteosarcoma patients may be the first sign of pulmonary metastases.

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

    Energy Technology Data Exchange (ETDEWEB)

    Regier, M.; Kaul, M.G.; Ittrich, H.; Bansmann, P.M.; Kemper, J.; Nolte-Ernsting, C.; Adam, G. [University Hospital of Hamburg, Center for Diagnostic Imaging and Image Guided Therapy, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Kandel, S.; Hoffmann, B.; Heller, M.; Biederer, J. [University Hospital of Kiel, Department of Diagnostic Radiology, Kiel (Germany)

    2007-05-15

    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.)

  12. Lung cancer probability in patients with CT-detected pulmonary nodules: a prespecified analysis of data from the NELSON trial of low-dose CT screening.

    Science.gov (United States)

    Horeweg, Nanda; van Rosmalen, Joost; Heuvelmans, Marjolein A; van der Aalst, Carlijn M; Vliegenthart, Rozemarijn; Scholten, Ernst Th; ten Haaf, Kevin; Nackaerts, Kristiaan; Lammers, Jan-Willem J; Weenink, Carla; Groen, Harry J; van Ooijen, Peter; de Jong, Pim A; de Bock, Geertruida H; Mali, Willem; de Koning, Harry J; Oudkerk, Matthijs

    2014-11-01

    The main challenge in CT screening for lung cancer is the high prevalence of pulmonary nodules and the relatively low incidence of lung cancer. Management protocols use thresholds for nodule size and growth rate to determine which nodules require additional diagnostic procedures, but these should be based on individuals' probabilities of developing lung cancer. In this prespecified analysis, using data from the NELSON CT screening trial, we aimed to quantify how nodule diameter, volume, and volume doubling time affect the probability of developing lung cancer within 2 years of a CT scan, and to propose and evaluate thresholds for management protocols. Eligible participants in the NELSON trial were those aged 50-75 years, who have smoked 15 cigarettes or more per day for more than 25 years, or ten cigarettes or more for more than 30 years and were still smoking, or had stopped smoking less than 10 years ago. Participants were randomly assigned to low-dose CT screening at increasing intervals, or no screening. We included all participants assigned to the screening group who had attended at least one round of screening, and whose results were available from the national cancer registry database. We calculated lung cancer probabilities, stratified by nodule diameter, volume, and volume doubling time and did logistic regression analysis using diameter, volume, volume doubling time, and multinodularity as potential predictor variables. We assessed management strategies based on nodule threshold characteristics for specificity and sensitivity, and compared them to the American College of Chest Physicians (ACCP) guidelines. The NELSON trial is registered at www.trialregister.nl, number ISRCTN63545820. Volume, volume doubling time, and volumetry-based diameter of 9681 non-calcified nodules detected by CT screening in 7155 participants in the screening group of NELSON were used to quantify lung cancer probability. Lung cancer probability was low in participants with a nodule

  13. Needle Biopsy of the Lung

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Needle Biopsy of the Lung Needle biopsy of the lung ... Needle Biopsy of Lung Nodules? What is Needle Biopsy of the Lung? A lung nodule is relatively ...

  14. 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

    Energy Technology Data Exchange (ETDEWEB)

    Hoop, Bartjan de [University Medical Center, Department of Radiology, Utrecht (Netherlands); University Medical Center, Heidelberglaan 100, GA, Utrecht (Netherlands); Gietema, Hester; Prokop, Mathias [University Medical Center, Department of Radiology, Utrecht (Netherlands); Ginneken, Bram van [University Medical Center, Image Sciences Institute, Utrecht (Netherlands); Zanen, Pieter [University Medical Center, Department of Pulmonology, Utrecht (Netherlands); Groenewegen, Gerard [University Medical Center, Department of Oncology, Utrecht (Netherlands)

    2009-04-15

    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.)

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

    Science.gov (United States)

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

    2013-08-01

    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). Fifty clinical multidetector CT datasets containing nodules up to 20mm in diameter were retrospectively collected. For the detection and rating of non-calcified nodules larger than 4mm 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. 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 132s with concurrent-reader CAD and 210s with second-reader CAD (preader CAD and 0.72 with second-reader CAD (p=0.35). 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. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. 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.

  17. Lung adenocarcinoma with GGO nodules:HRCT radiological and pathological correlation

    Institute of Scientific and Technical Information of China (English)

    ACHARYA Prashanta; PAUDEL Rasmita; XU Qiu-zhen

    2015-01-01

    Background:Lung cancer is the most common cancer related death in the world for the both male and female as well .Adenocarcinoma is the most common pathological type which is in increasing trend .With recent ad-vancement of screening of lung cancer with HRCT , GGO lesion has been noted frequently .GGO is a nonspecific finding that may be caused by various disorders , including inflammatory diseases , focal fibrosis , atypical adenoma-tous hyperplasia , bronchoalveolar carcinoma ( BAC) , and adenocarcinoma .This study intends to analyze the corre-lation between high resolutions computed tomography ( HRCT) findings and the pathological findings of lung adeno-carcinoma.Material and methods:Retrospective review of 16 cases of lung adenocarcinoma lesions after surgical resection.Tumors were defined as air containing type based on ratio of maximum dimension of the tumor on medias-tinal window to the maximum diameter of the tumor on lung window was≤50%and as solid density if the ratio was >50%.The correlation between CT findings ( homogenous/heterogeneous , airbronchogram , pleural tag , specula-tion, vascular involvement , pleural thickening , margin, shape ) and pathological findings were investigated .Re-sults:Of 3 air containing 2 were pre-invasive type and 1 was invasive .Among 13 solid density type all 13 were in-vasive type .Presence of speculation , heterogeneous appearance was found significantly associated with pathological invasion .Conclusion:Air containing type of small cells lung adenocarcinomas are preinvasive whereas solid densi-ties are invasive .Speculation and heterogeneous are significant factor in invasive adenocarcinoma .

  18. Trade-off between benefits, harms and economic efficiency of low-dose CT lung cancer screening: a microsimulation analysis of nodule management strategies in a population-based setting.

    Science.gov (United States)

    Treskova, Marina; Aumann, Ines; Golpon, Heiko; Vogel-Claussen, Jens; Welte, Tobias; Kuhlmann, Alexander

    2017-08-25

    In lung cancer screening, a nodule management protocol describes nodule assessment and thresholds for nodule size and growth rate to identify patients who require immediate diagnostic evaluation or additional imaging exams. The Netherlands-Leuvens Screening Trial and the National Lung Screening Trial used different selection criteria and nodule management protocols. Several modelling studies have reported variations in screening outcomes and cost-effectiveness across selection criteria and screening intervals; however, the effect of variations in the nodule management protocol remains uncertain. This study evaluated the effects of the eligibility criteria and nodule management protocols on the benefits, harms and cost-effectiveness of lung screening scenarios in a population-based setting in Germany. We developed a modular microsimulation model: a biological module simulated individual histories of lung cancer development from carcinogenesis onset to death; a screening module simulated patient selection, screening-detection, nodule management protocols, diagnostic evaluation and screening outcomes. Benefits included mortality reduction, life years gained and averted lung cancer deaths. Harms were costs, false positives and overdiagnosis. The comparator was no screening. The evaluated 76 screening scenarios included variations in selection criteria and thresholds for nodule size and growth rate. Five years of annual screening resulted in a 9.7-12.8% lung cancer mortality reduction in the screened population. The efficient scenarios included volumetric assessment of nodule size, a threshold for a volume of 300 mm(3) and a threshold for a volume doubling time of 400 days. Assessment of volume doubling time is essential for reducing overdiagnosis and false positives. Incremental cost-effectiveness ratios of the efficient scenarios were 16,754-23,847 euro per life year gained and 155,287-285,630 euro per averted lung cancer death. Lung cancer screening can be cost

  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, 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. Long-term follow-up of non-calcified pulmonary nodules (<10 mm) identified during low-dose CT screening for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, Michael M.; Logan, P.M.; Lee, Michael J. [Beaumont Hospital, Department of Radiology, Dublin (Ireland); Foley, Claire; Kenny, Dermot [Beaumont Hospital, Clinical Research Centre, RCSI, Dublin (Ireland); Costello, Richard W. [Beaumont Hospital, Respiratory Division, Dublin (Ireland)

    2012-09-15

    To assess the long-term stability of small (<10 mm) non-calcified pulmonary nodules (NCNs) in high-risk subjects initially screened for lung cancer using low-dose chest computed tomography (LDCCT). A total of 449 subjects initially underwent screening with serial LDCCT over a 2-year period. Participants identified as having NCNs {>=}10 mm were referred for formal lung cancer workup. NCNs <10 mm diameter were followed in accordance with the study protocol. Seven years after baseline screening, subjects with previously documented NCNs <10 mm, which were unchanged in size after the 2-year follow-up period, were re-imaged using LDCCT to assess for interval nodule growth. Eighty-three subjects with previously documented stable NCNs <10 mm underwent LDCCT at 7 years. NCNs were unchanged in 78 subjects and had decreased in size in 4 subjects. There was interval growth of an NCN (from 6 mm to 9 mm) in one subject re-imaged at 7 years, but this nodule has remained stable in size over a further 2-year follow-up period. Non-calcified pulmonary nodules <10 mm in size that are unchanged in size or smaller after 2 years of follow-up with LDCCT are most likely benign. (orig.)

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

    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) Heidelberg, Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Amalienstr. 5, 69126 Heidelberg (Germany); Department of Radiology, German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Wroblewski, Jacek [Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University of Heidelberg, Amalienstr. 5, 69126 Heidelberg (Germany); Department of Radiology, German Cancer Research Center (dkfz), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Lederlin, Mathieu [Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Department of Radiology, University Hospital of Rennes, F-35033 Rennes (France); University of Rennes 1, UEB, F-35043 Rennes (France); and others

    2015-05-15

    Highlights: • CAD on chest MDCT is robust over a wide range of exposure settings, and may be applied on low-dose MDCT. • Iterative reconstruction (IR) is not detrimental for CAD sensitivity. • IR may not be used for further dose reduction with CAD on low-dose MDCT. • IR may be applicable with CAD for management of low-dose MDCT for lung cancer screening. - Abstract: Objectives: 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). Material and methods: 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. Results: 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, p < 0.05). False positive findings ranged between 2.3 - 8.1 annotations per lung. For nodule volumes <200 μl the rate of true positives was significantly lower than for >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. Conclusions: 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

  2. MALDI-ToF mass spectrometry for the rapid diagnosis of cancerous lung nodules.

    Directory of Open Access Journals (Sweden)

    Fabienne Brégeon

    Full Text Available Recently, tissue-based methods for proteomic analysis have been used in clinical research and appear reliable for digestive, brain, lymphomatous, and lung cancers classification. However simple, tissue-based methods that couple signal analysis to tissue imaging are time consuming. To assess the reliability of a method involving rapid tissue preparation and analysis to discriminate cancerous from non-cancerous tissues, we tested 141 lung cancer/non-tumor pairs and 8 unique lung cancer samples among the stored frozen samples of 138 patients operated on during 2012. Samples were crushed in water, and 1.5 µl was spotted onto a steel target for analysis with the Microflex LT analyzer (Bruker Daltonics. Spectra were analyzed using ClinProTools software. A set of samples was used to generate a random classification model on the basis of a list of discriminant peaks sorted with the k-nearest neighbor genetic algorithm. The rest of the samples (n = 43 cancerous and n = 41 non-tumoral was used to verify the classification capability and calculate the diagnostic performance indices relative to the histological diagnosis. The analysis found 53 m/z valid peaks, 40 of which were significantly different between cancerous and non-tumoral samples. The selected genetic algorithm model identified 20 potential peaks from the training set and had 98.81% recognition capability and 89.17% positive predictive value. In the blinded set, this method accurately discriminated the two classes with a sensitivity of 86.7% and a specificity of 95.1% for the cancer tissues and a sensitivity of 87.8% and a specificity of 95.3% for the non-tumor tissues. The second model generated to discriminate primary lung cancer from metastases was of lower quality. The reliability of MALDI-ToF analysis coupled with a very simple lung preparation procedure appears promising and should be tested in the operating room on fresh samples coupled with the pathological examination.

  3. MALDI-ToF mass spectrometry for the rapid diagnosis of cancerous lung nodules.

    Science.gov (United States)

    Brégeon, Fabienne; Brioude, Geoffrey; De Dominicis, Florence; Atieh, Thérèse; D'Journo, Xavier Benoit; Flaudrops, Christophe; Rolain, Jean-Marc; Raoult, Didier; Thomas, Pascal Alexandre

    2014-01-01

    Recently, tissue-based methods for proteomic analysis have been used in clinical research and appear reliable for digestive, brain, lymphomatous, and lung cancers classification. However simple, tissue-based methods that couple signal analysis to tissue imaging are time consuming. To assess the reliability of a method involving rapid tissue preparation and analysis to discriminate cancerous from non-cancerous tissues, we tested 141 lung cancer/non-tumor pairs and 8 unique lung cancer samples among the stored frozen samples of 138 patients operated on during 2012. Samples were crushed in water, and 1.5 µl was spotted onto a steel target for analysis with the Microflex LT analyzer (Bruker Daltonics). Spectra were analyzed using ClinProTools software. A set of samples was used to generate a random classification model on the basis of a list of discriminant peaks sorted with the k-nearest neighbor genetic algorithm. The rest of the samples (n = 43 cancerous and n = 41 non-tumoral) was used to verify the classification capability and calculate the diagnostic performance indices relative to the histological diagnosis. The analysis found 53 m/z valid peaks, 40 of which were significantly different between cancerous and non-tumoral samples. The selected genetic algorithm model identified 20 potential peaks from the training set and had 98.81% recognition capability and 89.17% positive predictive value. In the blinded set, this method accurately discriminated the two classes with a sensitivity of 86.7% and a specificity of 95.1% for the cancer tissues and a sensitivity of 87.8% and a specificity of 95.3% for the non-tumor tissues. The second model generated to discriminate primary lung cancer from metastases was of lower quality. The reliability of MALDI-ToF analysis coupled with a very simple lung preparation procedure appears promising and should be tested in the operating room on fresh samples coupled with the pathological examination.

  4. Lung nodule malignancy classification using only radiologist-quantified image features as inputs to statistical learning algorithms: probing the Lung Image Database Consortium dataset with two statistical learning methods.

    Science.gov (United States)

    Hancock, Matthew C; Magnan, Jerry F

    2016-10-01

    In the assessment of nodules in CT scans of the lungs, a number of image-derived features are diagnostically relevant. Currently, many of these features are defined only qualitatively, so they are difficult to quantify from first principles. Nevertheless, these features (through their qualitative definitions and interpretations thereof) are often quantified via a variety of mathematical methods for the purpose of computer-aided diagnosis (CAD). To determine the potential usefulness of quantified diagnostic image features as inputs to a CAD system, we investigate the predictive capability of statistical learning methods for classifying nodule malignancy. We utilize the Lung Image Database Consortium dataset and only employ the radiologist-assigned diagnostic feature values for the lung nodules therein, as well as our derived estimates of the diameter and volume of the nodules from the radiologists' annotations. We calculate theoretical upper bounds on the classification accuracy that are achievable by an ideal classifier that only uses the radiologist-assigned feature values, and we obtain an accuracy of 85.74 [Formula: see text], which is, on average, 4.43% below the theoretical maximum of 90.17%. The corresponding area-under-the-curve (AUC) score is 0.932 ([Formula: see text]), which increases to 0.949 ([Formula: see text]) when diameter and volume features are included and has an accuracy of 88.08 [Formula: see text]. Our results are comparable to those in the literature that use algorithmically derived image-based features, which supports our hypothesis that lung nodules can be classified as malignant or benign using only quantified, diagnostic image features, and indicates the competitiveness of this approach. We also analyze how the classification accuracy depends on specific features and feature subsets, and we rank the features according to their predictive power, statistically demonstrating the top four to be spiculation, lobulation, subtlety, and

  5. 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.

  6. Solitary pulmonary nodule

    Science.gov (United States)

    ... Chest x-ray Granulomatosis with polyangiitis Histoplasmosis Lung cancer - small cell Pulmonary tuberculosis Skin nodules Valley fever Review Date 8/1/2015 Updated by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, ... Cancer Lung Diseases Browse the Encyclopedia A.D.A. ...

  7. Image-guided radiotherapy platform using single nodule conditional lung cancer mouse models.

    Science.gov (United States)

    Herter-Sprie, Grit S; Korideck, Houari; Christensen, Camilla L; Herter, Jan M; Rhee, Kevin; Berbeco, Ross I; Bennett, David G; Akbay, Esra A; Kozono, David; Mak, Raymond H; Mike Makrigiorgos, G; Kimmelman, Alec C; Wong, Kwok-Kin

    2014-12-18

    Close resemblance of murine and human trials is essential to achieve the best predictive value of animal-based translational cancer research. Kras-driven genetically engineered mouse models of non-small-cell lung cancer faithfully predict the response of human lung cancers to systemic chemotherapy. Owing to development of multifocal disease, however, these models have not been usable in studies of outcomes following focal radiotherapy (RT). We report the development of a preclinical platform to deliver state-of-the-art image-guided RT in these models. Presence of a single tumour as usually diagnosed in patients is modelled by confined injection of adenoviral Cre recombinase. Furthermore, three-dimensional conformal planning and state-of-the-art image-guided dose delivery are performed as in humans. We evaluate treatment efficacies of two different radiation regimens and find that Kras-driven tumours can temporarily be stabilized upon RT, whereas additional loss of either Lkb1 or p53 renders these lesions less responsive to RT.

  8. A Case of Multifocal Skin Metastases from Lung Cancer Presenting with Vasculitic-type Cutaneous Nodule

    Science.gov (United States)

    Babacan, Nalan Akgul; Kiliçkap, Saadettin; Sene, Soner; Kacan, Turgut; Yucel, Birsen; Eren, Mehmet Fuat; Cihan, Sener

    2015-01-01

    Although cutaneous metastasis occurs usually at the terminal stage of the disease, it may be rarely concurrent with the diagnosis and may also present as the first sign of the illness. A 55-year-old male patient presented with vasculitic-type cutaneous nodular lesions and a necrotic distal phalangeal lesion developed over the last month. He was a tradesman and smoked 40 packets year. On physical examination, he was found to have multiple cutaneous lesions on the skin of the face, limbs, neck, scalp, dorsal side, fingers, subungual side, right leg, and feet. A skin lesion punch biopsy was performed and squamous cell carcinoma metastasis was detected. He was diagnosed as having squamous cell lung cancer with bronchoscopic biopsy. Although it is very rare, cutaneous metastases that is concurrent with the diagnosis of lung cancer may be the first sign of the disease. In patients with suspicious skin lesions, the patient's age, smoking history, and other symptoms should be evaluated and a biopsy should be performed. PMID:25814739

  9. A case of multifocal skin metastases from lung cancer presenting with vasculitic-type cutaneous nodule

    Directory of Open Access Journals (Sweden)

    Nalan Akgul Babacan

    2015-01-01

    Full Text Available Although cutaneous metastasis occurs usually at the terminal stage of the disease, it may be rarely concurrent with the diagnosis and may also present as the first sign of the illness. A 55-year-old male patient presented with vasculitic-type cutaneous nodular lesions and a necrotic distal phalangeal lesion developed over the last month. He was a tradesman and smoked 40 packets year. On physical examination, he was found to have multiple cutaneous lesions on the skin of the face, limbs, neck, scalp, dorsal side, fingers, subungual side, right leg, and feet. A skin lesion punch biopsy was performed and squamous cell carcinoma metastasis was detected. He was diagnosed as having squamous cell lung cancer with bronchoscopic biopsy. Although it is very rare, cutaneous metastases that is concurrent with the diagnosis of lung cancer may be the first sign of the disease. In patients with suspicious skin lesions, the patient′s age, smoking history, and other symptoms should be evaluated and a biopsy should be performed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Depeursinge, Adrien, E-mail: adrien.depeursinge@hevs.ch [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 and Business Information Systems, University of Applied Sciences Western Switzerland (HES-SO), Sierre 3960 (Switzerland); Yanagawa, Masahiro [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 and Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Leung, Ann N.; Rubin, Daniel L. [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 (United States)

    2015-04-15

    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{sup −5}). Conclusions: This study

  11. 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.)

  12. Rheumatoid lung disease

    Science.gov (United States)

    Lung disease - rheumatoid arthritis; Rheumatoid nodules; Rheumatoid lung ... They often cause no symptoms. The cause of lung disease associated with rheumatoid arthritis is unknown. Sometimes, the ...

  13. Estimation of non-solid lung nodule volume with low-dose CT protocols: effect of reconstruction algorithm and measurement method

    Science.gov (United States)

    Gavrielides, Marios A.; DeFilippo, Gino; Berman, Benjamin P.; Li, Qin; Petrick, Nicholas; Schultz, Kurt; Siegelman, Jenifer

    2017-03-01

    Computed tomography is primarily the modality of choice to assess stability of nonsolid pulmonary nodules (sometimes referred to as ground-glass opacity) for three or more years, with change in size being the primary factor to monitor. Since volume extracted from CT is being examined as a quantitative biomarker of lung nodule size, it is important to examine factors affecting the performance of volumetric CT for this task. More specifically, the effect of reconstruction algorithms and measurement method in the context of low-dose CT protocols has been an under-examined area of research. In this phantom study we assessed volumetric CT with two different measurement methods (model-based and segmentation-based) for nodules with radiodensities of both nonsolid (-800HU and -630HU) and solid (-10HU) nodules, sizes of 5mm and 10mm, and two different shapes (spherical and spiculated). Imaging protocols included CTDIvol typical of screening (1.7mGy) and sub-screening (0.6mGy) scans and different types of reconstruction algorithms across three scanners. Results showed that radio-density was the factor contributing most to overall error based on ANOVA. The choice of reconstruction algorithm or measurement method did not affect substantially the accuracy of measurements; however, measurement method affected repeatability with repeatability coefficients ranging from around 3-5% for the model-based estimator to around 20-30% across reconstruction algorithms for the segmentation-based method. The findings of the study can be valuable toward developing standardized protocols and performance claims for nonsolid nodules.

  14. Cavitation bioeffects.

    Science.gov (United States)

    Kimmel, Eitan

    2006-01-01

    Acoustic cavitation takes place when tiny gas bubbles oscillate, grow, and collapse in liquid under the influence of ultrasonic field. This study reviews cavitation bioeffects that are found both in vivo and in vitro when exposed to either low- or high-power acoustics. Proposed mechanisms are discussed here as well based on theoretical studies, simulations and test bench experiments. Bioeffects are induced in living tissue once the gas bubble is, for instance, within a blood vessel in close vicinity to the endothelium or to the red blood cells. Conditions for inducing various bioeffects are discussed - from severe damage, such as cell necrosis, to delicate alterations, such as increased permeability of cell membrane. Present and potential applications for therapeutic purpose from stone pulverization and tissue ablation to gene transfection and transdermal delivery are reviewed including the growing use of artificial microbubbles.

  15. Analysis of the clinical characteristics between cavitating squamous cell lung carcinoma and non-cavitating squamous cell lung carcinoma%空洞型肺鳞癌与非空洞型肺鳞癌的临床特征分析

    Institute of Scientific and Technical Information of China (English)

    Aiwu Li; Caicun Zhou; Jianfang Xu; Jian Ni; Jie Zhang; Jingyun Shi; Jie Luo

    2007-01-01

    Objective:To identify the differences between cavitating squamous cell lung carcinoma (cSLC) and non-cavitating squamous cell lung carcinoma (ncSLC). Methods:Fifty-one patients with cSLC and 281 with ncSLC confirmed by surgery in our hospital between 1999 to 2000 were collected and their clinical, histological and survival features were retrospectively analyzed. Results:Patients with cSLC had more frequent manifestation of infection and weight loss. They usually experienced longer duration of pre-diagnosis and showed bigger tumor mass, larger primary tumor invasion with worse differentiated than ncSLC patients. There was no significant difference in age, sex, smoking history, family tumor history, personal tuberculosis history, disease location, TNM stage, lymph node invasion, and metastasis between the two groups. Median survival time was 29 months for cSLC and 35 months for ncSLC. One- and 3- year survival rates were 86.3% and 43.1% for cSLC vs. 91.1% and 47.0% for ncSLC respectively (P>0.05). Conclusion:Patients with cSLC presented with a bigger mass, a larger extent of primary tumor invasion, worse differentiated, more obstructed pneumonia that might result in longer duration of pre-diagnosis and more weight loss. As lack of differences in disease stages, lymph node invasion, metastasis and especially survival time with ncSLC, cSLC couldn't be classified as a special type of squamous cell carcinoma by present evidences.

  16. Rotating Cavitation Supression Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT proposes development of a rotating cavitation (RC) suppressor for liquid rocket engine turbopump inducers. Cavitation instabilities, such as rotating...

  17. Segmentation of pulmonary nodules in computed tomography using a regression neural network approach and its application to the Lung Image Database Consortium and Image Database Resource Initiative dataset.

    Science.gov (United States)

    Messay, Temesguen; Hardie, Russell C; Tuinstra, Timothy R

    2015-05-01

    We present new pulmonary nodule segmentation algorithms for computed tomography (CT). These include a fully-automated (FA) system, a semi-automated (SA) system, and a hybrid system. Like most traditional systems, the new FA system requires only a single user-supplied cue point. On the other hand, the SA system represents a new algorithm class requiring 8 user-supplied control points. This does increase the burden on the user, but we show that the resulting system is highly robust and can handle a variety of challenging cases. The proposed hybrid system starts with the FA system. If improved segmentation results are needed, the SA system is then deployed. The FA segmentation engine has 2 free parameters, and the SA system has 3. These parameters are adaptively determined for each nodule in a search process guided by a regression neural network (RNN). The RNN uses a number of features computed for each candidate segmentation. We train and test our systems using the new Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) data. To the best of our knowledge, this is one of the first nodule-specific performance benchmarks using the new LIDC-IDRI dataset. We also compare the performance of the proposed methods with several previously reported results on the same data used by those other methods. Our results suggest that the proposed FA system improves upon the state-of-the-art, and the SA system offers a considerable boost over the FA system.

  18. 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.

  19. 以双侧肺结节为临床表现的肺隐球菌性炎性假瘤1例及文献回顾%Pulmonary inflammatory pseudotumor caused by Cryptococcus presenting multiple nodules in bilateral lungs

    Institute of Scientific and Technical Information of China (English)

    刘立刚; 潘铁成; 魏翔

    2006-01-01

    By now there are a few reports describing a case of pulmonary inflammatory pseudotumor, presenting multiple nodules in bilateral lungs and a pseudotumor caused by fungus infection is also a very rare disease. Here we report a rare case of pulmonary inflammatory pseudotumor with confirmed cause by Cryptococcus infection presenting multiple nodules in bilateral lungs.

  20. Multiple pulmonary rheumatoid nodules.

    Science.gov (United States)

    Sargin, Gokhan; Senturk, Taskin

    2015-01-01

    We present a case of 45-year-old female patient with the diagnosis of seropositive rheumatoid arthritis, who was admitted to our rheumatology department with exacerbation of the disease. The patient's disease activity score (DAS 28) was 6.9. Physical examination revealed changes in the lung auscultation as a rough breathing sound at the middle and lower lobe of the right lung. Chest X-ray revealed multiple nodular densities in both lungs. Lung biopsy was performed for the diagnosis and revealed necrotizing granulomas with central fibrinoid necrosis surrounded by epithelioid cells. Such a histopathological picture is typical for rheumatoid nodules. Finally the patient was treated with rituximab, with significant improvement.

  1. 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

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

    Science.gov (United States)

    Breen, Micheál; Zurakowski, David; Lee, Edward Y

    2015-11-01

    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 patients had a history of malignancy. Of the remaining 31 patients

  3. Thyroid nodule

    Science.gov (United States)

    ... nodules are not always found, but can include: Hashimoto's disease Lack of iodine in the diet Symptoms ... nodules are sometimes found in people who have Hashimoto's disease. This may cause symptoms of an underactive ...

  4. Thyroid Nodules

    Science.gov (United States)

    ... Endocrinologist Search Featured Resource New Mobile App DOWNLOAD Thyroid Nodules March 2010 Download PDFs English Espanol Hindi ... Resources Mayo Clinic American Thyroid Association What are thyroid nodules and who is at risk? A thyroid ...

  5. Thyroid Nodules

    Science.gov (United States)

    ... very accurate for identifying cancerous or “suspicious” nodules. Thyroid ultrasound is used to get an exact picture of ... up may involve a physical exam or a thyroid ultrasound or both. If the nodule gets larger, you ...

  6. 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

  7. 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

  8. 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.

  9. Effect of austempering temperature on cavitation behaviour of unalloyed ADI material

    Energy Technology Data Exchange (ETDEWEB)

    Dojcinovic, Marina [University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade (Serbia); Eric, Olivera [Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade (Serbia); Rajnovic, Dragan; Sidjanin, Leposava [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia); Balos, Sebastian, E-mail: sebab@uns.ac.rs [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia)

    2013-08-15

    This paper provides an in-depth study and description of cavitation damage and microstructural changes in two types of unalloyed austempered ductile iron (ADI). ADI materials used were austempered at 300 and 400 °C having ausferrite microstructure with 16 and 31.4% of retained austenite, respectively. Metallographic examination was carried out to study the morphology of their cavitation-damaged surfaces. Cavitation damage was initiated at graphite nodules as well as in the interface between a graphite nodule and an ausferrite matrix. Furthermore, microcracking and ferrite/retained austenite morphology were proved to be of great importance for cavitation resistance. Mass loss rate revealed that ADI austempered at 400 °C has a higher cavitation resistance in water than ADI austempered at 300 °C. A higher amount of retained austenite in ADI austempered at 400 °C played an important role in increasing cavitation resistance. The good cavitation behaviour of ADI austempered at 400 °C was due to the matrix hardening by stress assisted phase transformation of retained austenite into martensite (SATRAM) phenomenon, as shown by X-ray diffraction analysis. - Highlights: • Cavitation rate of two ADI materials was tested. • ADI material with a lower hardness has had a lower cavitation rate. • The main reason is microstructural transformations during cavitation. • SATRAM phenomenon increases cavitation resistance.

  10. Manganese nodules

    Science.gov (United States)

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn

    2016-01-01

    The existence of manganese (Mn) nodules (Fig. 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published...

  11. 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

    2013-04-01

    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.

  12. 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

    space mediated by stromal fibroblasts, all of which are hall - marks of cancer [24,25]. Since a limitation of current CT based screening for lung cancer is...Biomedical Imaging (ISBI): From Nano to Macro; Barcelona, Spain: 2012. [16] Negahdar M, Amini AA. Tracking planar lung motion in 4D CT with optical

  13. The Application of Doubling Time in the Diagnosis of Following Up Lung Nodules%倍增时间的测定在肺小结节随访中的应用价值

    Institute of Scientific and Technical Information of China (English)

    周科峰; 朱斌; 秦国初; 何健; 李丹燕; 窦鑫

    2012-01-01

    目的 评估倍增时间的测定在肺小结节病变随访中的应用价值.材料和方法 初次胸部CT检查发现肺部小结节的病灶(直径?3cm)并有复查资料的患者共202例(确诊108例).其中直径< 5mm组16例,5~ 10mm组38例,11 ~20mm组123例,21~ 30mm组2 5例;按照结节的密度:实质性结节127例,部分实性的结节65例,磨玻璃样结节10例.采用GE Lightspeed Pro16螺旋CT扫描,工作站为AW4.2的高级肺结节分析(Advanced Lung Analysis,ALA)数据后处理软件,重建肺结节体积并计算其倍增时间及生长率,并与最终临床结果作对照.结果 磨玻璃样结节均重建失败,直径< 5mm的结节部分重建失败.良性或炎性结节其生长速度非常快,倍增时间小于30天,或生长速度非常缓慢或负生长,倍增时间超过180天以上或者为负值.恶性结节倍增时间分别为腺癌136±2天,鳞癌89±7天,大细胞癌118±9天,小细胞癌35±4天,转移癌61±5天.结论 在肺部小结节难以定性时,倍增时间可以作为定性诊断的重要指标.%Objective To evaluate the application value of doubling time in lung nodules lesions in the following-up. Materials and Methods 202 patients (108 cases diagnosed) who were found the lung nodule lesions (< 3 cm in diameter) by chest CT and had underwent CT scan at least twice. In all lesions, 16 cases in the group of diameter < 5mm, 38 cases in 5 - 10mm, 123 cases in 11 ~ 20mm and 25 cases in 21 ~ 30mm group. According to the density of nodes: 127 cases of substantial nodules, part of the solid nodules 65 cases, ground glass opacity nodules 10 cases. Using the GE Lightspeed Prol6 spiral CT and AW4.2 workstation, we reconstructed the lung nodules and calculated its volume doubling time with Advanced Lung Analysis software, taking the final clinical results as a control. Results Ground glass opacity sample nodules are all failed to reconstruct, and parts of nodules diameter < 5mm are also failed.Benign or

  14. Manganese nodules

    Science.gov (United States)

    Hein, James R.; Harff, Jan; Petersen, Sven; Thiede, Jorn

    2016-01-01

    The existence of manganese (Mn) nodules (Figure 1) has been known since the late 1800s when they were collected during the Challenger expedition of 1873–1876. However, it was not until after WWII that nodules were further studied in detail for their ability to adsorb metals from seawater. Many of the early studies did not distinguish Mn nodules from Mn crusts. Economic interest in Mn nodules began in the late 1950s and early 1960s when John Mero finished his Ph.D. thesis on this subject, which was published in the journal Economic Geology (Mero, 1962) and later as a book (Mero, 1965). By the mid-1970s, large consortia had formed to search for and mine Mn nodules that occur between the Clarion and Clipperton fracture zones (CCZ) in the NE Pacific (Figure 2). This is still the area considered of greatest economic potential in the global ocean because of high nickel (Ni), copper (Cu), and Mn contents and the dense distribution of nodules in the area. While the mining of nodules was fully expected to begin in the late 1970s or early 1980s, this never occurred due to a downturn in the price of metals on the global market. Since then, many research cruises have been undertaken to study the CCZ nodules, and now 15 contracts for exploration sites have been given or are pending by the International Seabed Authority (ISA). Many books and science journal articles have been published summarizing the early work (e.g., Baturin, 1988; Halbach et al., 1988), and research has continued to the present day (e.g., ISA, 1999; ISA, 2010). Although the initial attraction for nodules was their high Ni, Cu, and Mn contents, subsequent work has shown that nodules host large quantities of other critical metals needed for high-tech, green-tech, and energy applications (Hein et al., 2013; Hein and Koschinsky, 2014).

  15. 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.

  16. 非小细胞肺癌伴对侧肺内结节的外科治疗%Surgical treatment of non - small cell lung cancer with contralateral pulmonary nodules

    Institute of Scientific and Technical Information of China (English)

    胡涛; 晏大学; 王青涛

    2011-01-01

    Objective To investigate the diagnosis and therapeutic strategy of non - small cell lung cancer(NSCLC) with contralateral pulmonary nodules.Methods A total of 24 NSCLC patients with contralateral pulmonary nodules were given surgical treatments.Adjuvant chemotherapy and/or radiotherapy were performed after the operation.All the patients were followed up for 14 to 21 months.Results Among the 24 cases, six nodules were found to be primary or metastatic tumor.The size of nodules, the stage and type of primary lung cancer were not associated with the nature of nodules.Conclusion NSCLC with contralateral pulmonary nodule is not a contraindication to surgical treatment when the definite pathological results cannot be achieved.%目的 探讨非小细胞肺癌伴对侧肺结节的诊断及治疗.方法 24例获明确诊断的非小细胞肺癌患者伴对侧肺结节,均接受手术治疗,术后辅助放、化疗,并定期跟踪随访14~21个月.结果 24例患者中,其中6例有原发或转移癌;肺结节的大小,原发癌的病理类型和分期与结节性质之间无联系.结论 非小细胞肺癌患者伴对侧肺结节,如果不能取得病理学诊断,也并非是手术的禁忌证.

  17. 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.

  18. 两种CAD软件对体模肺结节CT体积测量的比较研究%Comparative study of two kinds of CAD softwares for volumetric measurement of lung nodules--a phantom study

    Institute of Scientific and Technical Information of China (English)

    李敏; 龚建平; 张伟; 钱铭辉

    2013-01-01

    Objective:To evaluate the accuracy and the consistency of CT phantom nodule volumetry measurement with pulmonary CT intellective CAD software and Lung VCAR sotware. Methods:Spherical nodules 2. 5mm, 5. 0mm, 10. 0mm and 20. 0mm in diameter were placed within a commercially available lung phantom and scanned by a 64 slice CT scanner. Nodule volume (V) was measured by the formula V= (4/3) 7trs. Automated nodule volume measurements were performed by using the two above mentioned CAD softwares independently. Results:The volume of all 16 nodules within the phantom could be measured and analyzed by the two softwares. The average relative errors of nodules 2. 5mm,5. 0mm, 10. 0mm and 20mm in diameter were 21. 1% ,-4. 7% , -1. 6% and -2. 3% respectively with pulmonary CT intellective CAD soltware. 1 ne average relative errors ol nodules 2.5mm,5.0mm, 10.0mm and 20.0mm in diameter were 15.5% 3. 1 % ,2. 7% and 1.4% respectively with Lung VCAR soltware. There was no substantial difference in the volume estima tions between the two CAD softwares by Bland Altman analysis. Conclusion: Although the accuracy of volumetry measure ment with pulmonary CT intellective CAD software was lower than that of lung VCAR,but still there was high consistency between the two CAD softwares.%目的:评估肺部CT智能诊断报告系统软件和Lung VCAR软件在测量体模结节体积方面的准确性和一致性.方法:使用植入直径为2.5、5.0、10.0和20.0mm的孤立结节的商用体模,采用64层螺旋CT机进行体模扫描.结节标准体积采用公式V=4/3πr3计算.分别使用肺部CT智能诊断报告系统软件和Lung VCAR软件对体模扫描数据进行分析,测量体模结节的体积.结果:两种软件对肺结节体模中16个结节均能进行相应的分析和体积测量.肺部CT智能诊断报告系统软件测量直径2.5、5.0、10.0和20.0mm结节体积的平均相对误差分别为21.1%、-4.7%、-1.6%和-2.3%;Lung VCAR软件的平均相对误差分别为15.5%

  19. The IASLC Lung Cancer Staging Project: Proposals for Coding T Categories for Subsolid Nodules and Assessment of Tumor Size in Part-Solid Tumors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer.

    Science.gov (United States)

    Travis, William D; Asamura, Hisao; Bankier, Alexander A; Beasley, Mary Beth; Detterbeck, Frank; Flieder, Douglas B; Goo, Jin Mo; MacMahon, Heber; Naidich, David; Nicholson, Andrew G; Powell, Charles A; Prokop, Mathias; Rami-Porta, Ramón; Rusch, Valerie; van Schil, Paul; Yatabe, Yasushi

    2016-08-01

    This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) and a uniform way to measure tumor size in part-solid tumors for the eighth edition of the tumor, node, and metastasis classification of lung cancer. In 2011, new entities of AIS, MIA, and lepidic predominant adenocarcinoma were defined, and they were later incorporated into the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system, the Tis category is proposed for AIS, with Tis (AIS) specified if it is to be distinguished from squamous cell carcinoma in situ (SCIS), which is to be designated Tis (SCIS). We also propose that MIA be classified as T1mi. Furthermore, the use of the invasive size for T descriptor size follows a recommendation made in three editions of the Union for International Cancer Control tumor, node, and metastasis supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA, and lepidic predominant adenocarcinoma, the suspected diagnosis and clinical staging should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus noninvasive size on the basis of solid versus ground glass components is not applicable to mucinous AIS, MIA, or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

  20. Dynamics of Vortex Cavitation

    NARCIS (Netherlands)

    Pennings, P.C.

    2016-01-01

    This thesis describes the mechanisms with which tip vortex cavitation is responsible for broadband pressure fluctuations on ship propellers. Hypotheses for these are described in detail by Bosschers (2009). Validation is provided by three main cavitation-tunnel experiments, one on a model propeller

  1. Cavitating Flow over a Mini Hydrofoil

    Institute of Scientific and Technical Information of China (English)

    LUO Xian-Wu; JI Bin; ZHANG Yao; XU Hong-Yuan

    2012-01-01

    We consider a cavitating flow over a mini hydrofoil (foil profile: Clark-Y-11.7) having a 14 mm chord length in a cavitation tunnel at various cavitation numbers. Experimental observations show that cavitating flows over a miniature hydrofoil display several types of cavitation behavior, such as cavitation inception, sheet cavitation, cloud cavitation and super cavitation with the decreasing cavitation number. Under the same cavitation conditions, cavitation over a mini hydrofoil would be suppressed in comparison to cavitation over an ordinary hydrofoil. This cavitation scale effect is suspected to be caused by the Reynolds number.%We consider a cavitating flow over a mini hydrofoil (foil profile:Clark-Y-11.7) having a 14mm chord length in a cavitation tunnel at various cavitation numbers.Experimental observations show that cavitating flows over a miniature hydrofoil display several types of cavitation behavior,such as cavitation inception,sheet cavitation,cloud cavitation and super cavitation with the decreasing cavitation number.Under the same cavitation conditions,cavitation over a mini hydrofoil would be suppressed in comparison to cavitation over an ordinary hydrofoil.This cavitation scale effect is suspected to be caused by the Reynolds number.

  2. 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.

  3. 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

  4. Sublobar Resection Margin Width Does Not Affect Recurrence of Clinical N0 Non-small Cell Lung Cancer Presenting as GGO-Predominant Nodule of 3 cm or Less.

    Science.gov (United States)

    Moon, Youngkyu; Lee, Kyo Young; Moon, Seok Whan; Park, Jae Kil

    2017-02-01

    Sublobar resection of lung cancer may benefit patients with lung cancer presenting as ground-glass opacity (GGO) nodules. The purpose of this study was to evaluate the effect of margin width on recurrence after sublobar resection in patients with clinical N0 non-small cell lung cancer presenting as GGO-predominant nodule. We conducted a retrospective chart review of 91 patients treated for clinical N0 non-small cell lung cancer ≤3 cm by sublobar resection with clear resection margins. We assigned them to two groups: GGO-predominant tumor and solid-predominant tumor. Each group was subdivided into two groups according to the margin width: resection margin ≤5 mm and resection margin >5 mm. We analyzed the clinicopathological findings and survival among these four groups. There was no recurrence in GGO-predominant tumors after sublobar resection. Margin width did not influence the recurrence in GGO-predominant tumors. In the cases of solid-predominant tumor, 5-year recurrence-free survival after sublobar resection according to margin width ≤5 and >5 mm was 24.2 and 79.6 %, respectively (p recurrence of solid-predominant tumors (hazard ratio 3.868, 95 % confidence interval 1.177-12.714, p = 0.026). The width between the tumor and resection margin does not affect the recurrence after R0 sublobar resection in patients with clinical N0 GGO-predominant lung cancer ≤3 cm. By contrast, margin width is a significant risk factor for recurrence after sublobar resection in patients with clinical N0 solid-predominant lung cancer.

  5. 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.

  6. Tracking time interval changes of pulmonary nodules on follow-up 3D CT images via image-based risk score of lung cancer

    Science.gov (United States)

    Kawata, Y.; Niki, N.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.; Moriyama, N.

    2013-03-01

    In this paper, we present a computer-aided follow-up (CAF) scheme to support physicians to track interval changes of pulmonary nodules on three dimensional (3D) CT images and to decide the treatment strategies without making any under or over treatment. Our scheme involves analyzing CT histograms to evaluate the volumetric distribution of CT values within pulmonary nodules. A variational Bayesian mixture modeling framework translates the image-derived features into an image-based risk score for predicting the patient recurrence-free survival. Through applying our scheme to follow-up 3D CT images of pulmonary nodules, we demonstrate the potential usefulness of the CAF scheme which can provide the trajectories that can characterize time interval changes of pulmonary nodules.

  7. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    is reproduced in the simulation. The overall results suggest the possibility of the cavitation model in the RANS solver to be used for practical applications in propeller design process as a complementary tool to the cavitation tunnel test and the other numerical methods. The outstanding issue for cloudy...... developed in the last decade. They show the potential for the simulation of propeller cavitation with robustness, but they are still to be more proved for practical applications. In the present work, hydrodynamic and numerical characteristics of several cavitation models developed for a viscous flow solver...... are investigated, and one of the cavitation models is verified for the cavitation simulation on marine propellers. Three cavitation models with a vapor transport equation and a cavitation model with a barotropic state law are implemented in the in-house RANS solver, EllipSys. The numerical results for cavitating...

  8. 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.

  9. Management of the Solitary Pulmonary Nodule.

    Science.gov (United States)

    Chan, Edward Y; Gaur, Puja; Ge, Yimin; Kopas, Lisa; Santacruz, Jose F; Gupta, Nakul; Munden, Reginald F; Cagle, Philip T; Kim, Min P

    2016-09-02

    Context .- Optimal management of the patient with a solitary pulmonary nodule entails early diagnosis and appropriate treatment for patients with malignant tumors, and minimization of unnecessary interventions and procedures for those with ultimately benign nodules. With the growing number of high-resolution imaging modalities and studies available, incidentally found solitary pulmonary nodules are an increasingly common occurrence. Objective .- To provide guidance to clinicians involved in the management of patients with a solitary pulmonary nodule, including aspects of risk stratification, workup, diagnosis, and management. Data Sources .- Data for this review were gathered from an extensive literature review on the topic. Conclusions .- Logical evaluation and management pathways for a patient with a solitary pulmonary nodule will allow providers to diagnose and treat individuals with early stage lung cancer and minimize morbidity from invasive procedures for patients with benign lesions.

  10. Cavitation in medicine.

    Science.gov (United States)

    Brennen, Christopher Earls

    2015-10-06

    We generally think of bubbles as benign and harmless and yet they can manifest the most remarkable range of physical effects. Some of those effects are the stuff of our everyday experience as in the tinkling of a brook or the sounds of breaking waves at the beach. But even these mundane effects are examples of the ability of bubbles to gather, focus and radiate energy (acoustic energy in the above examples). In other contexts that focusing of energy can lead to serious technological problems as when cavitation bubbles eat great holes through ships' propeller blades or cause a threat to the integrity of the spillways at the Hoover Dam. In liquid-propelled rocket engines, bubbles pose a danger to the stability of the propulsion system, and in artificial heart valves they can cause serious damage to the red blood cells. In perhaps the most extraordinary example of energy focusing, collapsing cavitation bubbles can emit not only sound, but also light with black body radiation temperatures equal to that of the sun (Brennen 1995 Cavitation and bubble dynamics). But, harnessed carefully, this almost unique ability to focus energy can also be put to remarkably constructive use. Cavitation bubbles are now used in a remarkable range of surgical and medical procedures, for example to emulsify tissue (most commonly in cataract surgery or in lithotripsy procedures for the reduction of kidney and gall stones) or to manipulate the DNA in individual cells. By creating cavitation bubbles non-invasively thereby depositing and focusing energy non-intrusively, one can generate minute incisions or target cancer cells. This paper will begin by briefly reviewing the history of cavitation phenomena and will end with a vision of the new horizons for the amazing cavitation bubble.

  11. Biological Effects of Acoustic Cavitation

    Science.gov (United States)

    2007-11-02

    rectified diffusion. 56 III. STABLE CAVITATION A. Introduction There are manv areas associated with the biological effects of ultrasound in which the...used said as cavitation indicators. Further, if clinical ultrasound systems are found to be inducing cavitation , either stable or transient, it will...O BIOLOGICAL EFFECTS OF ACOUSTIC CAVITATION by Lawrence A. Crum -- Physical Acoustics Research Laboratory Department of Physics and Astronomy ’ CTE

  12. A novel ultrasonic cavitation enhancer

    NARCIS (Netherlands)

    Fernandez Rivas, David; Verhaagen, Bram; 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 transmiss

  13. 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 transm

  14. Cystic fibrohistiocytic tumor of the lung presenting as a solitary lesion

    Directory of Open Access Journals (Sweden)

    gGiorgio Sgarbi

    2010-03-01

    Full Text Available Cystic fibrohistiocytic tumor of the lung is a rare neoplasm. In many cases it represents a metastasis from a benign or low-grade fibrohistiocytic tumor of the skin, but occasionally it may be primary. Radiologically it usually occurs as a cystic change of multiple pulmonary nodules, and pneumothorax is the most frequent presenting symptom. We present here a 16-year-old man with recurrent right pneumothorax. The patient had no his-tory of cutaneous fibrohistiocytic lesions. He underwent videothoracoscopic right apical segmentectomy, right lower lobe nodulectomy, and pleuroabrasion. Microscopy of the apical segmentectomy showed a cystic fibrohistio-cytic tumor, whereas the nodule of the lower lobe was an intraparenchymal lymph node. The patient is alive with no tumor recurrence. The differential diagnosis includes Langerhans cell histiocytosis, lymphangioleiomyomatosis, pleuropulmonary blastoma, and metastatic endometrial stromal sarcoma. This disease usually occurs with multiple pulmonary cysts and cavitation. This case is the first reported presenting as a single lesion.

  15. Acoustic cavitation movies

    Science.gov (United States)

    Crum, Lawrence A.

    2003-04-01

    Acoustic cavitation is a phenomenon that occurs on microsecond time scales and micron length scales, yet, it has many macroscopic manifestations. Accordingly, it is often difficult, at least for the author, to form realistic physical descriptions of the specific mechanisms through which it expresses itself in our macroscopic world. For example, there are still many who believe that cavitation erosion is due to the shock wave that is emitted by bubble implosion, rather than the liquid jet created on asymmetric collapse...and they may be right. Over the years, the author has accumulated a number of movies and high-speed photographs of cavitation activity, which he uses to form his own visual references. In the time allotted, he will show a number of these movies and photographs and discuss their relevance to existing technological problems. A limited number of CDs containing the presented materials will be available to interested individuals. [Work supported in part by the NIH, USAMRMC, and the ONR.

  16. The effect of late-phase contrast enhancement on semi-automatic software measurements of CT attenuation and volume of part-solid nodules in lung adenocarcinomas

    NARCIS (Netherlands)

    Cohen, J.G.; Goo, J.M.; Yoo, R.E.; Park, S.B.; Ginneken, B. van; Ferretti, G.R.; Lee, C.H.; Park, C.M.

    2016-01-01

    OBJECTIVES: To evaluate the differences in semi-automatic measurements of CT attenuation and volume of part-solid nodules (PSNs) between unenhanced and enhanced CT scans. MATERIALS AND METHODS: CT scans including unenhanced and enhanced phases (slice thickness 0.625 and 1.25mm, respectively) for 53

  17. Cavitation in liquid helium

    Energy Technology Data Exchange (ETDEWEB)

    Finch, R. D.; Kagiwada, R.; Barmatz, M.; Rudnick, I.

    1963-11-15

    Ultrasonic cavitation was induced in liquid helium over the temperature range 1.2 to 2.3 deg K, using a pair of identical transducers. The transducers were calibrated using a reciprocity technique and the cavitation threshold was determined at 90 kc/s. It was found that this threshold has a sharp peak at the lambda point, but is, at all temperatures quite low, with an approximate range of 0.001 to 0.01 atm. The significance of the results is discussed. (auth)

  18. Taming Acoustic Cavitation

    CERN Document Server

    Rivas, David Fernandez; Enriquez, Oscar R; Versluis, Michel; Prosperetti, Andrea; Gardeniers, Han; Lohse, Detlef

    2012-01-01

    In this fluid dynamics video we show acoustic cavitation occurring from pits etched on a silicon surface. By immersing the surface in a liquid, gas pockets are entrapped in the pits which upon ultrasonic insonation, are observed to shed cavitation bubbles. Modulating the driving pressure it is possible to induce different behaviours based on the force balance that determines the interaction among bubbles and the silicon surface. This system can be used for several applications like sonochemical water treatment, cleaning of surfaces with deposited materials such as biofilms.

  19. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    flows on a 2D hydrofoil are compared with the experimental results. In the current implementation, three models with a vapor transport equation show numerical stability and equivalently good accuracy in simulating steady and unsteady sheet cavitation. More validations for cavitating flows on 3D...... 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...

  20. Herniation of malignant lung cavity

    Institute of Scientific and Technical Information of China (English)

    Saurabh Kumar Singh; Rakesh Bhargava; Zuber Ahmad; Deepak K.Pandey; Shirin Naaz; Vibhanshu Gupta

    2008-01-01

    @@ Hernia of the lung is defined as a protrusion of lung tissue,covered by parietal and visceral pleurae,through an abnormal opening in the chest wall,diaphragm or mediastinum.1 It is a relatively uncommon condition.We report a case of lung hernia following cavitation in malignant lung mass.

  1. Cavitation Instabilities in Inducers

    Science.gov (United States)

    2006-11-01

    gas handling turbomachines . The fluctuation of the cavity length is plotted in Fig.8 under the surge mode oscillation vi . The major differences...Cavitation Instabilities of Turbomachines .” AIAA Journal of Propulsion and Power, Vol.17, No.3, 636-643. [5] Tsujimoto, Y., (2006), “Flow Instabilities in

  2. Cavitation during wire brushing

    Science.gov (United States)

    Li, Bo; Zou, Jun; Ji, Chen

    2016-11-01

    In our daily life, brush is often used to scrub the surface of objects, for example, teeth, pots, shoes, pool, etc. And cleaning rust and stripping paint are accomplished using wire brush. Wire brushes also can be used to clean the teeth for large animals, such as horses, crocodiles. By observing brushing process in water, we capture the cavitation phenomenon on the track of moving brush wire. It shows that the cavitation also can affect the surface. In order to take clear and entire pictures of cavity, a simplified model of one stainless steel wire brushing a boss is adopted in our experiment. A transparent organic tank filled with deionized water is used as a view box. And a high speed video camera is used to record the sequences. In experiment, ambient pressure is atmospheric pressure and deionized water temperature is kept at home temperature. An obvious beautiful flabellate cavity zone appears behind the moving steel wire. The fluctuation of pressure near cavity is recorded by a hydrophone. More movies and pictures are used to show the behaviors of cavitation bubble following a restoring wire. Beautiful tracking cavitation bubble cluster is captured and recorded to show.

  3. Acoustic cavitation and sonochemistry

    NARCIS (Netherlands)

    Stricker, L.

    2013-01-01

    Sonochemistry is the use of cavitation for achieving a chemical conversion. When microbubbles are driven in the nonlinear regime, localized extreme temperatures (up to 10000 K) and pressures (up to 1000 bar) can be reached upon collapse, the surrounding liquid remaining ambient,thus giving origin to

  4. Ozone and Cavitation Combination

    Science.gov (United States)

    Carreon, Ernestina; Traversoni, Leonardo

    2009-09-01

    From laboratory measurements it is well known that the addition of ozone and cavitation enhances the properties of both, understanding for that the ones related to disinfection and carbon removal from waste water. This paper shows modeling of such phenomena that gives some light to the understanding of it and also provides the opportunity to improve the effectiveness of the current procedures.

  5. Extra-pleuric coaxial system for CT-guided percutaneous fine-needle aspiration biopsy (FNAB) of small (≤20 mm) lung nodules: a novel technique using multiplanar reconstruction (MPR) images.

    Science.gov (United States)

    Capasso, Raffaella; Nizzoli, Rita; Tiseo, Marcello; Pedrazzi, Giuseppe; Brunese, Luca; Rotondo, Antonio; De Filippo, Massimo

    2017-02-01

    The aim of the study is to present the diagnostic feasibility, usefulness, and safety of a novel technique for coaxial CT-guided fine-needle aspiration biopsy of small (≤20 mm in diameter) lung nodules. A 18-gauge (G) (1.2 × 40 mm) needle is inserted through the skin in the depth of the thoracic wall tissues remaining outside the pleura. Its positioning is planned and adjusted using multiplanar reconstruction (MPR) images along the 18-G guide needle axis tracing a reference outline extended from the needle tip to the target nodule. When the insertion of the 18-G extra-pleuric needle (EPN) proves to be precise, a 22-G Chiba needle is then passed through the outer 18-G EPN until it reaches the thoracic lesion for the sampling procedure. Patient population included 153 males and 94 females, with a mean age of 61.3 ± 21.6 years. Mean nodule diameter was 14.1 ± 2.2 mm. The lesion depth from pleural plane ranged from 0 mm to 127 mm. An average of 1.29 aspirates were performed per lesion. The most common complication was pneumothorax in 27 cases; there were no cases of PNX requiring chest tube insertion. Intrapulmonary bleeding along the needle track was observed in 32 patients. Exploiting the advantage of MPR images, our novel technique of extra-pleuric coaxial system with a 18-G EPN allows the operator to multiple samplings of small (≤20 mm) target lesions in various locations with a thinner (22-G Chiba) needle, thus reducing the degree of pleural, parenchymal, or adjacent organs damage.

  6. 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.

  7. Designing A New CAD System for Pulmonary Nodule Detection in High Resolution Computed Tomography (HRCT Images

    Directory of Open Access Journals (Sweden)

    M Bakhshayesh Karam

    2012-07-01

    Full Text Available Background: Lung diseases and lung cancer are among the most dangerous diseases with high mortality in both men and women. Lung nodules are abnormal pulmonary masses and are among major lung symptoms. A Computer Aided Diagnosis (CAD system may play an important role in accurate and early detection of lung nodules. This article presents a new CAD system for lung nodule detection from chest computed tomography (CT images.Methods: Twenty-five adult patients with lung nodules in their CT scan images presented to the National Research Institute of Tuberculosis and Lung Disease, Masih Daneshvari Hospital, Tehran, Iran in 2011-2012 were enrolled in the study. The patients were randomly assigned into two experimental (9 female, 6 male, mean age 43±5.63 yrs and control (6 female, 4 male, mean age 39±4.91 yrs groups. A fully-automatic method was developed for detecting lung nodules by employing medical image processing and analysis and statistical pattern recognition algorithms.esults: Using segmentation methods, the lung parenchyma was extracted from 2-D CT images. Then, candidate regions were labeled in pseudo-color images. In the next step, some features of lung nodules were extracted. Finally, an artificial feed forward neural network was used for classification of nodules.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.

  8. Characteristics of Vibration Induced by Cavitation

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-yu; TAO Lei; LIU Shu-yan; QIAN Jian-jun

    2005-01-01

    Cavitation-induced vibration characteristics and the relations between the vibration and cavitation are studied. Cavitation vibrations are measured around a model hollow-jet valve by an accelerometer under cavitating and non-cavitating conditions. The measurement data is analyzed by FFT method. The corresponding cavitating flow patterns are photographed by a high-speed camera with an xenon flash lamp. The frequency band of the vibration induced by cavitation is determined. To compare the vibration intensities under different cavitation conditions, a definition of vibration acceleration level is introduced based on power spectral density of the vibration. By the analysis of vibration, the definitions of characteristic cavitation number are suggested. According to these cavitation numbers, the cavitation process is divided into three stages, that is, incipient cavitation, subcavitation and supercavitation.

  9. Robust semi-automatic segmentation of pulmonary subsolid nodules in chest computed tomography scans

    NARCIS (Netherlands)

    Lassen, B.C.; Jacobs, C.; Kuhnigk, J.-M.; Ginneken, B. van; Rikxoort, E.M. van

    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 dis

  10. CT灌注成像鉴别肺癌与炎性结节的初步探讨%The value of computed tomography perfusion imaging in differential diagnosis for inlfammatory nodule and lung cancer

    Institute of Scientific and Technical Information of China (English)

    傅钢泽; 陈勇春; 谢福荣

    2015-01-01

    目的:探讨多层螺旋CT灌注成像对肺炎性结节与肺癌的鉴别价值。方法:选取2010年6月至2013年6月在我院欲行手术切除的孤立肺结节患者,先行肺部结节CT灌注成像检查,通过灌注软件计算肺癌和肺炎性结节患者的灌注参数,包括血容量(BV)、血流量(BF)、表面渗透系数(PS)和平均通过时间(MTT),并测量强化峰值(PH)、达峰值时间(TTP)、结节-主动脉强化峰值比(PHSPN/PHAA);用Mann-Whitney法比较2组间参数有无差异。结果:32例患者中肺癌26例和炎性结节6例,炎性结节组BF、PH、PHSPN/PHAA均大于肺癌结节组,差异有统计学意义(P<0.05)。炎性结节组与肺癌结节组的BV、PS差异无统计学意义(P>0.05)。以BF=78 mL·min-1·100 g-1作为炎性和肺癌结节区分阈值,其敏感度为88.5%,特异度为100%,阳性预测值为100%,阴性预测值为66.7%,准确度为90.6%。以PHSPN/PHAA=8.5%作为炎性和肺癌结节区分阈值,其敏感度为80.8%,特异度为83.3%,阳性预测值为95.5%,阴性预测值为50.0%,准确度为81.3%。结论:CT灌注成像对炎性结节及肺癌具有一定的鉴别价值。%Objective: To evaluate the value of computed tomography perfusion imaging in distinguishing inlfammatory and malignant nodules.Methods: CT perfusion scans were performed in patients with lung nodule received CT perfusion between September 2010 and February 2013. Patients with lung cancer and/or inlfamma-tory nodule were conifrmed by operation and proved by pathology. The parameters of CT perfusion, including blood volume (BV), blood lfow (BF), permeability-surface area product (PS), mean transit time (MTT) were pro-duced by perfusion software, and peak high (PH), time to peak (TTP), PHSPN/PHAA were measured. CTP parame-ters between above subgroups were analyzed using Mann-Whitney test.Results: Thirty-two cases were effective, including 26 cases of lung

  11. Volumetric measurements of pulmonary nodules: variability in automated analysis tools

    Science.gov (United States)

    Juluru, Krishna; Kim, Woojin; Boonn, William; King, Tara; Siddiqui, Khan; Siegel, Eliot

    2007-03-01

    Over the past decade, several computerized tools have been developed for detection of lung nodules and for providing volumetric analysis. Incidentally detected lung nodules have traditionally been followed over time by measurements of their axial dimensions on CT scans to ensure stability or document progression. A recently published article by the Fleischner Society offers guidelines on the management of incidentally detected nodules based on size criteria. For this reason, differences in measurements obtained by automated tools from various vendors may have significant implications on management, yet the degree of variability in these measurements is not well understood. The goal of this study is to quantify the differences in nodule maximum diameter and volume among different automated analysis software. Using a dataset of lung scans obtained with both "ultra-low" and conventional doses, we identified a subset of nodules in each of five size-based categories. Using automated analysis tools provided by three different vendors, we obtained size and volumetric measurements on these nodules, and compared these data using descriptive as well as ANOVA and t-test analysis. Results showed significant differences in nodule maximum diameter measurements among the various automated lung nodule analysis tools but no significant differences in nodule volume measurements. These data suggest that when using automated commercial software, volume measurements may be a more reliable marker of tumor progression than maximum diameter. The data also suggest that volumetric nodule measurements may be relatively reproducible among various commercial workstations, in contrast to the variability documented when performing human mark-ups, as is seen in the LIDC (lung imaging database consortium) study.

  12. Shock Waves in Cloud Cavitation

    OpenAIRE

    Brennen, C. E.; Reisman, G. E.; Wang, Y.-C.

    1997-01-01

    Thie paper described experimental and computational investigations of the dynamics of clouds of cavitation bubbles. Recent studies have confirmed that the interactions between bubbles as they are manifest in the dynamics of bubble clouds lead to generation of very large impulsive pressures which, in turn, cause substantial enhancement of the radiated noise and the material damage which results from this form of cavitation. The experimental program focuses on cloud cavitation formed on th...

  13. A novel ultrasonic cavitation enhancer

    OpenAIRE

    Rivas, Fernandez D.; Verhaagen, B.; Galdamez Perez, Andres; Castro-Hernandez, Elena; Zwieten, van, D.M.; 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 transmission of ultrasound, temperature increase inside the bag during sonication. Several applications of interest to other scientific activities are also demonstrated.

  14. 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

  15. CAD System for Pulmonary Nodule Detection Using Gabor Filtering and Template Matching

    Science.gov (United States)

    Bastawrous, Hany Ayad; Nitta, Norihisa; Tsudagawa, Masaru

    This paper aims at developing a Computer Aided Diagnosis (CAD) system used for the detection of pulmonary nodules in chest Computed Tomography (CT) images. These lung nodules include both solid nodules and Ground Glass Opacity (GGO) nodules. In our scheme, we apply Gabor filter on the CT image in order to enhance the detection process. After this we perform some morphological operations including threshold process and labeling to extract all the objects inside the lung area. Then, some feature analysis is used to examine these objects to decide which of them are likely to be potential cancer candidates. Following the feature examination, a template matching between the potential cancer candidates and some Gaussian reference models is performed to determine the similarity between them. The algorithm was applied on 715 slices containing 25 GGO nodules and 82 solid nodules and achieved detection sensitivity of 92% for GGO nodules and 95% for solid nodules with False Positive (FP) rate of 0.75 FP/slice for GGO nodules and 2.32 FP/slice for solid nodules. Finally, we used an Artificial Neural Network (ANN) to reduce the number of FP findings. After using ANN, we were able to reduce the FP rate to 0.25 FP/slice for GGO nodules and 1.62 FP/slice for solid nodules but at the expense of detection sensitivity, which became 84 % for GGO nodules and 91% for solid nodules.

  16. Pulmonary nodule detection in CT images based on shape constraint CV model

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing; Tian, Xuedong [College of Mathematics and Computer Science, Hebei University, Baoding 071002 (China); Wang, Qian [Hebei Geological Laboratory, Baoding 071000, China and Multi-disciplinary Research Center, Hebei University, Baoding 071002 (China); Yang, Ying [Hebei University Affiliated Hospital, Baoding 071002 (China); Xie, Hongzhi, E-mail: gulixu@sjtu.edu.cn, E-mail: xiehongzhi@medmail.com.cn; Zhang, Shuyang [Department of Cardiology, Peking Union Medical College Hospital, Peking 100005 (China); Gu, Lixu, E-mail: gulixu@sjtu.edu.cn, E-mail: xiehongzhi@medmail.com.cn [Multi-disciplinary Research Center, Hebei University, Baoding 071002, China and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2015-03-15

    Purpose: Accurate detection of pulmonary nodules remains a technical challenge in computer-aided diagnosis systems because some nodules may adhere to the blood vessels or the lung wall, which have low contrast compared to the surrounding tissues. In this paper, the analysis of typical shape features of candidate nodules based on a shape constraint Chan–Vese (CV) model combined with calculation of the number of blood branches adhered to nodule candidates is proposed to reduce false positive (FP) nodules from candidate nodules. Methods: The proposed scheme consists of three major stages: (1) Segmentation of lung parenchyma from computed tomography images. (2) Extraction of candidate nodules. (3) Reduction of FP nodules. A gray level enhancement combined with a spherical shape enhancement filter is introduced to extract the candidate nodules and their sphere-like contour regions. FPs are removed by analysis of the typical shape features of nodule candidates based on the CV model using spherical constraint and by investigating the number of blood branches adhered to the candidate nodules. The constrained shapes of CV model are automatically achieved from the extracted candidate nodules. Results: The detection performance was evaluated on 127 nodules of 103 cases including three types of challenging nodules, which are juxta-pleural nodules, juxta-vascular nodules, and ground glass opacity nodules. The free-receiver operating characteristic (FROC) curve shows that the proposed method is able to detect 88% of all the nodules in the data set with 4 FPs per case. Conclusions: Evaluation shows that the authors’ method is feasible and effective for detection of three types of nodules in this study.

  17. Dictionary learning-based CT detection of pulmonary nodules

    Science.gov (United States)

    Wu, Panpan; Xia, Kewen; Zhang, Yanbo; Qian, Xiaohua; Wang, Ge; Yu, Hengyong

    2016-10-01

    Segmentation of lung features is one of the most important steps for computer-aided detection (CAD) of pulmonary nodules with computed tomography (CT). However, irregular shapes, complicated anatomical background and poor pulmonary nodule contrast make CAD a very challenging problem. Here, we propose a novel scheme for feature extraction and classification of pulmonary nodules through dictionary learning from training CT images, which does not require accurately segmented pulmonary nodules. Specifically, two classification-oriented dictionaries and one background dictionary are learnt to solve a two-category problem. In terms of the classification-oriented dictionaries, we calculate sparse coefficient matrices to extract intrinsic features for pulmonary nodule classification. The support vector machine (SVM) classifier is then designed to optimize the performance. Our proposed methodology is evaluated with the lung image database consortium and image database resource initiative (LIDC-IDRI) database, and the results demonstrate that the proposed strategy is promising.

  18. 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.

  19. [Preoperative localization and anchoring of pulmonary nodules under computed tomography guidance].

    Science.gov (United States)

    Bonfioli, C; Varoli, F; Motta, F; Bergonzi, M; Urani, A; Roviaro, G

    1993-03-01

    Videoendoscopic thoracic surgery is often employed to remove peripheral lung nodules. Since manual palpation is excluded, the authors obviate the difficulty of intraoperative nodule localization by employing a thin snap open mandrel under CT to guidance localize, fix and anchor the nodule. Traction can be exerted on the device allowing for rapid nodule identification and facilitating wedge resection removal. This technical innovation, as yet applied only to a limited number of cases, widens the indications of videothoracoscopic surgery and appears complication-free.

  20. Controlled Cavitation in Microfluidic Systems

    NARCIS (Netherlands)

    Zwaan, Ed; le Gac, Severine; Tsuji, Kinko; Ohl, C.D.

    2007-01-01

    We report on cavitation in confined microscopic environments which are commonly called microfluidic or lab-on-a-chip systems. The cavitation bubble is created by focusing a pulsed laser into these structures filled with a lght-absorbing liquid. At hte center of a 20 mu m thick and 1 mm wide channel,

  1. NUMERICAL SIMULATIONS OF CAVITATING FLOWS

    Institute of Scientific and Technical Information of China (English)

    Wu Lei

    2003-01-01

    A new model, which involves viscous and multi-phase effects, was given to study cavitating flows. A local compressible model was established by introducing a density-pressure function to account for the two-phase flow of water/vapor and the transition from one phase to the other. An algorithm for calculating variable-density N-S equations of cavitating flow problem was put forward. The present method yields reasonable results for both steady and unsteady cavitating flows in 2D and 3D cases. The numerical results of unsteady character of cavitating flows around hydrofoils coincide well with experimental data. It indicates the feasibility to apply this method to a variety of cavitating flows of practical problems.

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

    Institute of Scientific and Technical Information of China (English)

    Jun CAI; Xiulan HUAI; Xunfeng LI

    2009-01-01

    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 (corre-sponding to the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial mo-tion 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.

  3. 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

    2012-03-07

    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.

  4. 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.)

  5. Profuse coarse pulmonary nodules in a patient with lymphangioleiomyomatosis

    DEFF Research Database (Denmark)

    Rasmussen, Daniel B; Shaker, Saher B; Seersholm, Niels

    2014-01-01

    Lymphangioleiomyomatosis (LAM) is a rare disease characterized by progressive cystic destruction of the lungs. We present an unusual radiological presentation of lymphangioleiomyomatosis in a patient followed for 33 years with profuse coarse lung nodules in addition to the classical cystic lesions...

  6. Dynamic response of cavitating turbomachines

    Science.gov (United States)

    Ng, S. L.

    1976-01-01

    Stimulated by the pogo instability encountered in many liquid propellant rockets, the dynamic behavior of cavitating inducers is discussed. An experimental facility where the upstream and downstream flows of a cavitating inducer could be perturbed was constructed and tested. The upstream and downstream pressure and mass flow fluctuations were measured. Matrices representing the transfer functions across the inducer pump were calculated from these measurements and from the hydraulic system characteristics for two impellers in various states of cavitation. The transfer matrices when plotted against the perturbing frequency showed significant departure from steady state or quasi-steady predictions especially at higher frequencies.

  7. Flow Instabilities in Cavitating and Non-Cavitating Pumps

    Science.gov (United States)

    2006-11-01

    stall and surge may occur in non-cavitating turbomachines at flow rates smaller than design. Rotating stall is a local instability at the...turbomachinery which is basically not dependent on the hydraulic system in which the turbomachine is installed. The stalled region rotates faster than impeller...rate and without significant head decrease. So, it is required to confirm the absence of cavitation instabilities, whenever the turbomachine is

  8. Microleakage of Cavit, CavitW, CavitG and IRM by impedance spectroscopy.

    Science.gov (United States)

    Jacquot, B M; Panighi, M M; Steinmetz, P; G'Sell, C

    1996-07-01

    The aim of this study was to quantify the sealing ability of four temporary filling materials over 9 days using a new electrochemical technique. Fifty-two extracted human maxillary bicuspids were selected and prepared for the measurements. They were divided into four groups of 12 teeth each, in addition to two positive and two negative controls. After preparation of the endodontic access cavity the sealing ability was registered. After a randomization procedure one group was obturated with IRM, another group with Cavit, a third group with CavitW and the last group with CavitG. The sealability was measured just after obturation (time 0) and after days 1, 2, 3, 4, 7 and 9. The results showed that the IRM group was significantly more watertight than the different Cavit formulations. Throughout the experiment no significant difference was noticed between the Cavit and CavitW groups (P > 0.05). The CavitG group was significantly less watertight throughout the measurements (P < 0.05).

  9. Measuring blood delivery to solitary pulmonary nodules using perfusion magnetic resonance imaging

    Science.gov (United States)

    Zheng, Wei; Wang, Zhifeng; Shen, Li; Gao, Ling; Ford, James C.; Makedon, Fillia S.; Pearlman, Justin D.

    2006-03-01

    With perfusion magnetic resonance imaging (pMRI), perfusion describes the amount of blood passing through a block of tissue in a certain period of time. In pMRI, the tissue having more blood passing through will show higher intensity value as more contrast-labeled blood arrives. Perfusion reflects the delivery of essential nutrients to a block of tissue, and is an important parameter for the tissue status. Considering solitary pulmonary nodules (SPN), perfusion differences between malignant and benign nodules have been studied by different techniques. Much effort has been put into its characterization. In this paper, we proposed and implemented extraction of the SPN time intensity profile to measure blood delivery to solitary pulmonary nodules, describing their perfusion effects. In this method, a SPN time intensity profile is created based on intensity values of the solitary pulmonary nodule in lung pMRI images over time. This method has two steps: nodule tracking and profile clustering. Nodule tracking aligns the solitary pulmonary nodule in pMRI images taken at different time points, dealing with nodule movement resulted from breathing and body movement. Profile clustering implements segmentation of the nodule region and extraction of the time intensity profile of a solitary pulmonary nodule. SPN time intensity profiles reflect patterns of blood delivery to solitary pulmonary nodules, giving us a description of perfusion effect and indirect evidence of tumor angiogenesis. Analysis on SPN time intensity profiles will help the diagnosis of malignant nodules for early lung cancer detection.

  10. 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.

  11. 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......The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years...

  12. 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

  13. The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Application of TNM Staging Rules to Lung Cancer Presenting as Multiple Nodules with Ground Glass or Lepidic Features or a Pneumonic Type of Involvement in the Forthcoming Eighth Edition of the TNM Classification.

    Science.gov (United States)

    Detterbeck, Frank C; Marom, Edith M; Arenberg, Douglas A; Franklin, Wilbur A; Nicholson, Andrew G; Travis, William D; Girard, Nicolas; Mazzone, Peter J; Donington, Jessica S; Tanoue, Lynn T; Rusch, Valerie W; Asamura, Hisao; Rami-Porta, Ramón

    2016-05-01

    Application of tumor, node, and metastasis (TNM) classification is difficult in patients with lung cancer presenting as multiple ground glass nodules or with diffuse pneumonic-type involvement. Clarification of how to do this is needed for the forthcoming eighth edition of TNM classification. A subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee conducted a systematic literature review to build an evidence base regarding such tumors. An iterative process that included an extended workgroup was used to develop proposals for TNM classification. Patients with multiple tumors with a prominent ground glass component on imaging or lepidic component on microscopy are being seen with increasing frequency. These tumors are associated with good survival after resection and a decreased propensity for nodal and extrathoracic metastases. Diffuse pneumonic-type involvement in the lung is associated with a worse prognosis, but also with a decreased propensity for nodal and distant metastases. For multifocal ground glass/lepidic tumors, we propose that the T category be determined by the highest T lesion, with either the number of tumors or m in parentheses to denote the multifocal nature, and that a single N and M category be used for all the lesions collectively-for example, T1a(3)N0M0 or T1b(m)N0M0. For diffuse pneumonic-type lung cancer we propose that the T category be designated by size (or T3) if in one lobe, as T4 if involving an ipsilateral different lobe, or as M1a if contralateral and that a single N and M category be used for all pulmonary areas of involvement. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  14. PRESSURE CHARACTERISTICS OF CAVITATION CONTROL BY AERATION

    Institute of Scientific and Technical Information of China (English)

    DONG Zhi-yong; LU Yang-quan; JU Wen-jie; CAI Xin-ming; DING Chun-sheng

    2005-01-01

    This experimental investigation was systematically conducted with the aid of a non-circulating water tunnel in the Hydraulics Laboratory at Zhejiang University of Technology in China.The test velocity is between 20m/s and 40m/s.The least air concentration to prevent cavitation erosion lies between 1.7% and 4.5%.Pressure waveforms with and without aeration in cavitation and cavitation erosion regions were measured.Time-averaged pressure profiles with and without aeration were compared.Pressure characteristics corresponding to least air concentration to prevent cavitation erosion in cavitation and cavitation erosion regions were analyzed.

  15. 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)

  16. Juxta-vascular nodule segmentation based on flow entropy and geodesic distance.

    Science.gov (United States)

    Sun, Shenshen; Guo, Yang; Guan, Yubao; Ren, Huizhi; Fan, Linan; Kang, Yan

    2014-07-01

    Computed aided diagnosis of lung CT data is a new quantitative analysis technique to distinguish malignant nodules from benign ones. Nodule growth rate is a key indicator to discriminate between benign and malignant nodules. Accurate nodule segmentation is the essential for calculating the nodule growth rate. However, it is difficult to segment juxta-vascular nodules, due to the similar gray levels in nodule and attached blood vessels. To distinguish the nodule region from the adjacent vessel region, a flowing direction feature, referred to as the direction of the normal vector for a pixel, is introduced. Since blood is flowing in one single direction through a vessel, the normal vectors of pixels in the vessel region typically point in similar orientations while the directions of those in the nodule region can be viewed as disorganized. The entropy value of the flowing direction features in a neighboring region for a vessel pixel is smaller than that for a nodule pixel. Moreover, vessel pixels typically have a larger geodesic distance to the nodule center than nodule pixels. Based on k -means clustering method, the flow entropy, combined with the geodesic distance, is used to segment vessel attached nodules. The validation of the proposed segmentation algorithm was carried out on juxta-vascular nodules, identified in the Chinalung-CT screening trial and on Lung Image Database Consortium (LIDC) dataset. In fully automated mode, accuracies of 92.9% (26/28), 87.5%(7/8), and 94.9% (149/157) are reached for the outlining of juxta-vascular nodules in the Chinalung-CT, and the first and second datasets of LIDC, respectively. Furthermore, it is demonstrated that the proposed method has low time complexity and high accuracies.

  17. 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

  18. Visualization of cavitation bubbles; Visualisation de bulles de cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Chouvellon, M.; Fournel, Th.; Ducottet, Ch. [Universite Jean Monnet, 31 Saint-Etienne (France). Laboratoire Traitement du Signal et Instrumentation-UMR CNRS 5516

    1999-07-01

    A high frequency ultrasonic reactor allows the degradation of some organic compounds which are not or poorly biodegradable by usual methods in industrial flows. The propagation of an ultrasonic wave in a liquid induces cavitation phenomena. The implosion of cavitation bubble locally causes a temperature of about several thousand Kelvins and a pressure of about several hundred bars. Such conditions allow the creation of the hydroxyl radicals and then the oxidation of organic compounds. The aim of this paper is to describe the method used to visualize cavitation bubbles in an ultrasonic reactor at a frequency of 500 kHz. The experimental set-up and the measurement of both the bubble radius and the fringe separation are presented. (authors)

  19. 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

  20. Evaluation of effectiveness of a computer system (CAD) in the identification of lung nodules with low-dose MSCT: scanning technique and preliminary results; Valutazione dell'efficacia di un sistema computerizzato (CAD) nell'identificazione dei noduli polmonari con TSMS a basso dosaggio: tecnica di sudio e risultati preliminari

    Energy Technology Data Exchange (ETDEWEB)

    Fraioli, Francesco; Catalano, Carlo; Almberger, Maria; Bertoletti, Linda; Cantisani, Vito; Danti, Massimiliano; Pediconi, Federica; Passariello, Roberto [La Sapienza Univ., Roma (Italy). Dipartimento di Scienze Radiologiche

    2005-02-01

    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. [Italian] Scopo: Valutazione dell'efficacia di un sistema computerizzato (CAD) nell'identificazione di noduli polmonari. Materiale e metodi: Due osservatori (A1, A2) con differente livello di esperienza hanno valutato 20 esami di TC multistrato del torace con e senza l'ausilio di un sistema CAD (LungCheck, R2 Technology, Inc.). I parametri di studio utilizzati sono stati i seguenti

  1. Fluorine-18 fluorodeoxyglucose positron emission tomography in the management of solitary pulmonary nodule: a review.

    Science.gov (United States)

    Divisi, Duilio; Barone, Mirko; Zaccagna, Gino; Crisci, Roberto

    2017-11-01

    Solitary pulmonary nodules are common radiologic findings and their detection has increased due to the introduction and improvement of diagnostics. Since a nodule can be an expression of early lung cancers, a proper classification and management are required because its treatment might lead to decreased morbidity and mortality. In this regard, prominent guidelines are available although they are characterized sometimes by discordant and misleading evidences. Furthermore, the same results of studies in the literature appear conflicting. Aim of this work is to evaluate the role of imaging through an extensive literature review but focusing on 18-fluorine fluorodeoxyglucose positron emission tomography combined with computed tomography ((18)F-FDG-PET/CT) in order to assess the limits and future perspectives of solitary pulmonary nodule characterization in early detection of lung cancer. Key messages Detection of solitary pulmonary nodules has increased. Management of solitary pulmonary nodules is still debated. Future perspectives of early solitary pulmonary nodule characterization.

  2. Cavitation Effects in Centrifugal Pumps- A Review

    Directory of Open Access Journals (Sweden)

    Maxime Binama

    2016-05-01

    Full Text Available Cavitation is one of the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump flow behaviors and physical characteristics. Centrifugal pumps’ most low pressure zones are the first cavitation victims, where cavitation manifests itself in form of pitting on the pump internal solid walls, accompanied by noise and vibration, all leading to the pump hydraulic performance degradation. In the present article, a general description of centrifugal pump performance and related parameters is presented. Based on the literature survey, some light were shed on fundamental cavitation features; where different aspects relating to cavitation in centrifugal pumps were briefly discussed

  3. 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...

  4. Pump Cavitation Noise Estimation from Acceleration Signals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Do Hwan; Ha, Che Woong [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The cavitation noise can be measured directly by using pressure sensing devices. However, penetration of pipes or pump casings is inevitable to install the devices. This increases the risk of leaks. In an effort to reduce that risk, a cavitation noise estimation model based on vibration signals has been proposed. In the present study, the applicability of cavitation noise estimation methods including the previously proposed model is investigated. In order to assess the severity of cavitation, the cavitation noise estimation is necessary. In the present study, the cavitation noise is estimated by using acceleration signals measured outside of pumps and the theory of the statistical energy analysis. The applicability and limit of the cavitation noise estimation from the acceleration signals are examined by comparing the cavitation noise obtained from the pressure signal. The results suggest that the acoustic cavitation inception can be detected by the cavitation noise estimation from acceleration signals. The accuracy of the cavitation noise estimates is highly dependent on the locations of the pump casing that accelerometers attached on and the cut-off frequency of high pass filtering.

  5. Cavitation pulse extraction and centrifugal pump analysis

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hong Lind Shaoran [University of Electronic Science and Technology of China, Chengdu (China); Yu, Bo; Qing, Biao [Xihua University, Chengdu (China)

    2017-03-15

    This study extracted cavitation pulses from hydrophone signals sampled in a centrifugal pump and analyzed their characteristics. The modified and simplified Empirical mode decomposition (EMD) algorithm was proposed for extracting cavitation pulses from strong background noise. Experimental results showed that EMD can effectively suppress noise and obtain clear cavitation pulses, facilitating the identification of the number of pulses associated with the degree of cavitation. The cavitation characteristics were modeled to predict the value of incipient cavitation. Then, we proposed a method for detecting the wear of the impeller surface. That is, the information on the impeller surface of the centrifugal pump, including the roughness of the impeller surface and its wear trends, were quantified based on the net positive suction head available of incipient cavitation. The findings indicate that the proposed technique is suitable for condition monitoring of the pump.

  6. Pulmonary nodule follow-up : be careful with volumetry between contrast enhanced and unenhanced CT

    NARCIS (Netherlands)

    Mohamed Hoesein, Firdaus A; Bülbül, Metin; de Jong, Pim A

    2016-01-01

    Incident pulmonary nodules are a frequent finding on chest computed tomography (CT) of the lungs requiring follow-up. This case illustrates the importance of taking differences in CT scanning techniques (contrast versus non-contrast enhanced) into account. Comparing nodule size on unenhanced follow-

  7. Iatrogenic Pulmonary Nodule in a Heart Transplant Recipient

    Directory of Open Access Journals (Sweden)

    Atul C. Mehta

    2014-01-01

    Full Text Available A 58-year-old female with a history of non-Hodgkin lymphoma and end-stage nonischemic cardiomyopathy from Adriamycin toxicity underwent orthotic heart transplantation during June 2013. She developed shortness of breath in September 2013 and was suspected to have invasive pulmonary aspergillosis. A flexible bronchoscopy (FB with a transbronchial biopsy (TBBx was performed. She was found to have a focal lung nodule in the same location at the site of the TBBx on day 13 after the FB. Spontaneous resolution of the nodule was confirmed on the computed tomography (CT scan of chest performed at 3 months. We believe that this nodule was as a consequence of the TBBx. Formation of a peripheral pulmonary nodule (PPN following a TBBx is occasionally encountered among the recipients of the lung transplantation. To our knowledge, this is the first case of TBBx producing a pulmonary nodule in a heart transplant recipient. Physicians caring for the patients with heart transplantation should be cognizant of the iatrogenic nature of such nodule to avoid unnecessary diagnostic work-up.

  8. 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.)

  9. Experimental Observations of Cavitating Flows Around a Hydrofoil

    Institute of Scientific and Technical Information of China (English)

    ZHANG Min-di; WANG Guo-yu; DONG Zi-qiao; LI Xiang-bin; GAO De-ming

    2008-01-01

    The cavitation around a hydrofoil is studied experimentally tO shed light on the multiphase fluid dynamies.Different cavitation regimes are studied by using high speed visualization and particle image velocimetry(PIV).As decreasing the cavitation number,four cavitating flow regimes are observed:incipient cavitation,sheet cavitation,cloud cavitation,and supercavitation.From the incipient cavitation to the cloud cavitation,bubbles become more and more.Phenomena with large-scale vortex structure and rear re-entrant jet associated with the cloud cavitation,and subsequent development in the supercavitation are described.The velocity in the cavitation regions in the different cavitation conditions is low compared to that of the free stream.The large velocity gradient is also observed in the cavitating flow region near the suHace of the hydrofoil.

  10. Stochastic-field cavitation model

    Energy Technology Data Exchange (ETDEWEB)

    Dumond, J., E-mail: julien.dumond@areva.com [AREVA Nuclear Professional School, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); AREVA GmbH, Erlangen, Paul-Gossen-Strasse 100, D-91052 Erlangen (Germany); Magagnato, F. [Institute of Fluid Mechanics, Karlsruhe Institute of Technology, Kaiserstrasse 12, D-76131 Karlsruhe (Germany); Class, A. [AREVA Nuclear Professional School, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2013-07-15

    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.

  11. 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.

  12. Size effects on cavitation instabilities

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2006-01-01

    In metal-ceramic systems the constraint on plastic flow leads to so high stress triaxialities that cavitation instabilities may occur. If the void radius is on the order of magnitude of a characteristic length for the metal, the rate of void growth is reduced, and the possibility of unstable cavi...... as the void grows to a size well above the characteristic material length....

  13. 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 ha

  14. [Multiple pulmonary nodules and posterior uveitis as unusual manifestation of pulmonary tuberculosis].

    Science.gov (United States)

    Ibarburen González-Arenas, C; Zapatero Gaviria, A; Gómez Santos, D; García-Castaño, B; Tomás Ros, M; Merino Morales, F

    1990-12-01

    Pulmonar tuberculosis still being one of the diseases more frequent in our area, this producing different clinical and radiological presentation. A case with posterior uveitis and bilateral lungs nodules which required a thoracotomy to perform a diagnosis, is presented.

  15. Milker′s nodule

    Directory of Open Access Journals (Sweden)

    Kaviarasan P

    2009-01-01

    Full Text Available Milker′s nodule virus is a parapox virus that is endemic in cattle. The virus can be grown in tissue culture of both bovine and human cell lines. We report a 53-year-old male, milker who presented with multiple painful nodules on both hands for one month. The nodules were tender and showed central umblication and surrounding rim of erythema. Both epitrochlear and axillary lymph nodes were enlarged on both sides and were non-tender. The skin biopsy revealed marked edema in the epidermis with monouclear inflammatory cell infilitration in the upper dermis. The diagnosis was made on clinical basis. As there was no specific treatment the patient was managed only with antibiotics for secondary infection. The lesions partially resolved after two weeks. This case in reported for its occupational importance.

  16. 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...

  17. Role of cavitation in the phacoemulsification process.

    Science.gov (United States)

    Zacharias, Jaime

    2008-05-01

    To determine the role of cavitational energy as a mechanism responsible for the emulsification of the lens during phacoemulsification. Clinica Ophthalmologica Pasteur, Santiago, Chile. Cavitation and its relationship to phacoemulsification power were documented using a combination of light sources, high-speed video recording techniques, and computerized control and by monitoring environmental pressure. The suppression of cavitation from the phaco process was achieved by building an environmental hyperbaric system capable of retaining the phacoemulsification system's ability to provide irrigation, aspiration, and vacuum necessary at standard and elevated pressures. The pressure level was controlled and monitored through a computer interface alongside the simultaneous video monitoring of cavitation bubble creation changes during pressure rise or fall. Last, evaluation and measurement of phacoemulsification was performed on real cataract fragments in the presence and absence of cavitation. Cavitation around the phaco tip mainly occurred at longitudinal ultrasonic power levels of 30% or more. Cavitation bubble formation was observed during the backstroke or as the tip moved away from the lens material and collapsed during the forward displacement of the phaco tip. Cavitation at any power level was successfully suppressed when the pressure in the hyperbaric chamber increased beyond 2.0 bar (29.1 psi) above atmospheric pressure. Phacoemulsification performance in the presence or absence of cavitation was comparable. This study found strong evidence that cavitation plays no role in phacoemulsification, leaving the jackhammer effect as the only important mechanism responsible for the lens-disrupting power of phacoemulsification.

  18. Numerical Investigation Cavitation Buckets for Hydrofoil Parametrically

    Directory of Open Access Journals (Sweden)

    Mehmet Salih KARAALİOĞLU

    2015-12-01

    Full Text Available Cavitation is a general fluid mechanics phenomenon that is appeared in system such as pumps, turbines, marine propellers and hydrofoils which induces pressure and velocity fluctuation in the fluid (Brennen, 2013. Cavitation can be defined as the formation of vapour regions due to a decrease in local pressure. Undesirable consequences which can cause a fall in the performance of a system, structural failure, production of noise and vibration, material damage, are encountered due to cavitation (Uşar, 2015. In this study, cavitation was analysed using a bucket diagram. Bucket diagram represents the cavitation behaviour of a wing, fin or propeller blade in a two dimensional sense. This diagram is plotted as a function of section (hydrofoil angle of attack (α versus section cavitation number (σ. Pressure distribution can be calculated on two dimensional geometry of hydrofoil by using BEM (Boundary Element Method and cavitation bucket diagram can be computed. The cavitation inception case and partial cavitation cases have been investigated and the results of the present BEM were successfully compared with those of given in literature in the past and each other. While a constant source-dipole panel method has been used to calculate the pressure distribution at cavitation inception case, PCPAN programme that solves the sheet type of cavity on the hydrofoil by potential based panel method, has been used to calculate pressure distribution for the cases of partial cavitation. Effects of maximum hydrofoil thickness, maximum camber and location of maximum camber on cavitation have been analyzed by means of cavitation bucklet diagrams. All results are discussed in a detailed manner.

  19. Strategy for polymetallic nodule mining

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.

    , geological, technical and economic conditions, a singe polymetallic nodule mining operation can be carried out for a period of lime 4 • There are several factors for selection of a mine sites sucha~: Nodule distribution, grade and abundance Distribution... (Ol As = (C) (E) (M) Where As= annual nodule recovery rate (dmllycar) D = d'urdtion of mining operation (years) . C =average nodule abundance in mineable area (dmt/sq.km) E =-overall mining efficiency (perccnt) M =proportion of mineable area...

  20. Lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Kazerooni, E.A. [Univ. of Michigan Medical Center, Ann Arbor, MI (United States)

    2005-11-15

    Lung cancer screening with CT remains controversial. Lung cancer is the leading cause of cancer death. To date, no screening test has been demonstrated to reduce mortality. Given the large population of adult cigarette smokers and former smokers worldwide, there is a large population at risk for lung cancer. While a lot has been learned from prospective single-arm cohort studies about the feasibility of performing annual CT to screen for lung cancer, many questions have also been raised. While we know that screening for lung cancer with CT detects many small nodules, with up to half the subjects having a positive baseline screen, and up to 75% of subjects having a positive screen at least once if screened annually for 5 years, the great majority of these nodules exhibit benign biologic behavior. The innumerable small nodules detected with screening CT, and diagnostic chest CT in general, present a daily clinical challenge, and result in extensive medical resource utilization and additional radiation exposure. Algorithms for how and when to follow small nodules detected on CT are in evolution. Ongoing studies are designed to determine if lung cancer screening with CT reduces lung cancer mortality. (orig.)

  1. Prediction of cryogenic cavitation around hydrofoil by an extensional Schnerr-Sauer cavitation model

    Science.gov (United States)

    Sun, T. Z.; Wei, Y. J.; Wang, C.

    2015-12-01

    Developing a robust computational strategy to address the rich physics characteristic involved in the thermodynamic effects on the cryogenic cavitation remains a challenging problem. The objective of this present study is to model the numerical methodology to simulate the cryogenic cavitation by implanting the thermodynamic effects to the Schnerr-Sauer cavitation model, and coupling the energy equation considered the latent heat. For this purpose, cavitating flows are investigated over a three dimensional hydrofoil in liquid hydrogen and nitrogen. Experimental measurements of pressure and temperature are utilized to validate the extensional Schnerr-Sauer cavitation model. Specifically, the further analysis of the cavitation solution with respect to the thermodynamic term is conducted. The results show that the extensional Schnerr-Sauer cavitation model predicts better accuracy to the quasi-steady cavitation over hydrofoil in the two cryogenic fluids.

  2. Achromobacter xylosoxidans infection presenting as a pulmonary nodule mimicking cancer.

    Science.gov (United States)

    Claassen, Stephanie L; Reese, Jason M; Mysliwiec, Vincent; Mahlen, Steven D

    2011-07-01

    Achromobacter xylosoxidans is typically isolated from pulmonary sources, presenting as pneumonia in immunosuppressed individuals. We describe a novel clinical presentation of A. xylosoxidans infection presenting as multiple spiculated, pulmonary nodules mimicking cancer for which the patient underwent a wedge resection of the lung for diagnosis and staging of presumptive cancer.

  3. NODUL TIROID SOLITER

    Directory of Open Access Journals (Sweden)

    I Gusti Ayu Prema Yani Sidemen

    2014-10-01

    Full Text Available Latar Belakang: Nodul tiroid adalah pembengkakan atau massa pada kelenjar tiroid.Pembedahan merupakan pilihan terapi utama, namun pembedahan yang tidak dilakukandengan baik berisiko tinggi mencederai 2 struktur penting, yakni kelenjar paratiroid dannervus rekuren laringeal. Risiko nodul tiroid akan meningkat seiring pertambahan usiadan kurangnya asupan sodium.Insiden terjadinya nodul tiroid lebih sering ditemukanpada laki-laki dan usia di atas 50 tahun, namun pada kasus ini nodul tiroid soliterditemukan pada seorang perempuan dewasa muda sehingga melatar belakangi penulisuntuk mendiskusikan kasus ini dalam laporan kasus.Kasus: Seorang pasien perempuan 32 tahun dengan keluhan tumbuh benjolan padaleher kiri sejak ± 1 tahun yang lalu. Benjolan tersebut dirasakan semakin membesar.Pasien tidak mengeluhkan rasa nyeri di daerah benjolan. Gangguan pada saat makanataupun minum, riwayat sesak, dada berdebar-debar, sering berkeringat, ataupunpenurunan berat badan disangkal. Pada pemeriksaan fisik didapatkan keadaan umumdalam batas normal.  Pada pemeriksaan status lokalis pada region colli anterior lateralsinistra ditemukan massa lunak yang mobile dengan batas tegas dan ukuran ± 3,2 cm x3,4 cm.Hasil: Hasil pemeriksaan patologi anatomi menunjukkan terdapat degenerasi kistikpada massa tiroid tersebut. Pasien kemudian menjalani tindakan pembedahan, yaknitiroidektomi dengan isthmolobectomy. Tiroidektomi dengan teknik diseksi kapsularpada pasien ini berhasil dibuktikan dengan tidak terdapatnya kerusakan pita suara ataukejang pasca operasi.Kesimpulan: Kondisi pasca tiroidektomi dengan teknik diseksi kapsular pada pasien inibaik, tidak terdapat komplikasi kerusakan pita suara dan nervus rekuren laringeal,pasien hidup, dan luka operasi terawat baik.

  4. The evolution of nodulation

    NARCIS (Netherlands)

    Gualtieri, G.; Bisseling, T.

    2000-01-01

    In this review we will first describe the different steps leading to nodule formation, and these will be compared with processes of non-symbiotic plant development and growth. In general, aspects of both actinorhizal as well as rhizobial symbiosis are described, but in several cases, the emphasis wi

  5. 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

    We present a fully automatic method for the assessment of spiculation of pulmonary nodules in low-dose Computed Tomography (CT) images. Spiculation is considered as one of the indicators of nodule malignancy and an important feature to assess in order to decide on a patient-tailored follow......-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...... 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...

  6. Applications of Video-assisted Thoracic Surgery for the Diagnosis and Treatment 
of Patients with Small Pulmonary Nodules

    Directory of Open Access Journals (Sweden)

    Liqun SHAN

    2013-07-01

    Full Text Available Background and objective Chest computed tomography (CT, particularly thin-slice high resolution CT, has low sensitivity and specificity for detecting pulmonary nodules <10 mm in size. This limitation leads to challenges in clinical diagnosis and treatment of small pulmonary nodules. This study introduces the use of video-assisted thoracoscopic surgery (VATS for the diagnosis and treatment of small pulmonary nodules. Methods From November 2009 to May 2012, 64 patients with small pulmonary nodules without prior preoperative pathologic diagnosis were treated by pulmonary wedge resection through VATS. The diagnosis of small pulmonary nodules was established from rapid frozen section. The type of operation depends on the pathology and the condition of the patients. Twenty patients with primary lung cancer were subjected to lobectomy and radical resection of the lymph nodes by complete thoracospic lobectomy or video-assisted thoracoscopic invasive lobectomy. Pulmonary wedge resection was performed in 44 patients, among whom 21 have benign nodule, 18 have precancerous lesion, 3 have metastatic nodule, and 2 have primary lung cancer for which lobectomy was not fit. Results Confirmative diagnosis is difficult to obtain among patients with small pulmonary nodules. VATS is effective in the diagnosis and treatment of small pulmonary nodules. With VATS, patients with benign small pulmonary nodules can be cured, and patients with primary lung cancer can receive definite diagnosis and effective treatment in time. Conclusion CT-guided hook-wire fixation is useful in precise lesion localization for surgical resection.

  7. Cavitation study of a pump-turbine at turbine mode with critical cavitation coefficient condition

    Science.gov (United States)

    Wang, J.; Yang, D.; Xu, J. W.; Liu, J. T.; Jiao, L.

    2016-05-01

    To study the cavitation phenomenon of a pump-turbine at turbine mode when it ran at the critical cavitation coefficient condition, a high-head model pump-turbine was disperse using hexahedron grid. Three dimensional, steady cavitating flow was numerically studied using SST k-ω model. It is confirmed that ZGB cavitation model and SST k-ω model are useful ways to study the two-phase cavitation flow in pump-turbine. Mass flow inlet and pressure outlet were specified at the casing inlet and draft tube outlet, respectively. The static pressure was set according to the cavitation coefficient. The steady cavitating flows at critical cavitation coefficient condition were analysed. The cavitation area in the runner was investigated. It was found that the pressure of the suction on the blade surface was decreasing gradually with the decrease of the cavitation coefficient. In addition, the vortex flow in the draft tube was observed at the critical cavitation coefficient. It was found that the vortex flow appeared at the center of the draft tube inlet with the decreasing of the cavitation coefficient. Compared with the experimental data, the simulation results show reasonable agreement with the experimental data.

  8. Memory-Effect on Acoustic Cavitation

    OpenAIRE

    Yavaṣ, Oğuz; Leiderer, Paul; Park, Hee K.; Grigoropoulos, Costas P.; Poon, Chie C.; Tam, Andrew C.

    1994-01-01

    The formation of bubbles at a liquid-solid interface due to acoustic cavitation depends particularly on the preconditions of the interface. Here, it wiIl be shown that following laser-induced bubble formation at the interface the acoustic cavitation efficiency is strongly enhanced. Optical reflectance measurements reveal that this observed enhancement of acoustic cavitation due to preceding laser-induced bubble formation, which could be termed as memory effect, decays in a few hundred microse...

  9. Measuring Dynamic Transfer Functions of Cavitating Pumps

    Science.gov (United States)

    Baun, Daniel

    2007-01-01

    A water-flow test facility has been built to enable measurement of dynamic transfer functions (DTFs) of cavitating pumps and of inducers in such pumps. Originally, the facility was intended for use in an investigation of the effects of cavitation in a rocket-engine low-pressure oxygen turbopump. The facility can also be used to measure DTFs of cavitating pumps in general

  10. 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....

  11. CAVITATION NUCLEI: EXPERIMENTS AND THEORY

    Institute of Scientific and Technical Information of China (English)

    MфRCH K. A.

    2009-01-01

    The Swedish astrophysicist and Nobel Prize winner Hannes Alfvén 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.

  12. Mesenteric lymph node cavitation syndrome

    Institute of Scientific and Technical Information of China (English)

    Hugh; James; Freeman

    2010-01-01

    The mesenteric lymph node cavitation syndrome consists of central necrosis of mesenteric lymph nodes and may occur with either celiac disease or a sprue-like intestinal disease that fails to respond to a gluten-free diet. Splenic hypofunction may also be present. The cause is not known but its development during the clinical course of celiac disease is usually indicative of a poor prognosis for the intestinal disorder, a potential for signif icant compli-cations including sepsis and malignancy, particularly...

  13. Acoustic Cavitation and Bubble Dynamics.

    Science.gov (United States)

    1985-06-15

    Achilles tendon of a cow. Presently ceramic piezoelectrics are widely used to generate ultrasonic signals, as they are relatively inexpensive and can...the application of a negative pressure could result in a rupture of the liquid while d’Alembert refused to accept this view. The rise of cavitation as a...contraction resulted in the liquid undergoing a tensile stress, eventually ending in the rupture of the liquid. The temperature at which rupture occurred was

  14. Breaking beer bottles with cavitation

    Science.gov (United States)

    Jung, Sunny; Fontana, Jake; Palffy-Muhoray, Peter; Shelley, Michael

    2009-03-01

    Hitting the top of a beer bottle, nearly full of water, with an open hand can cause the bottle to break, with the bottom separating from upper section. We have studied this phenomenon using a high-speed camera, and observed the formation, coalescence and collapse of bubbles. The breaking of glass is due to cavitation, typically occurring near the bottom edge. We make numerical estimates of the relevant physical parameters, and compare these with experimental observations.

  15. Cavitation on hydrofoils with sinusoidal leading edge

    Science.gov (United States)

    Johari, H.

    2015-12-01

    Cavitation characteristics of hydrofoils with sinusoidal leading edge were examined experimentally at a Reynolds number of 7.2 × 105. The hydrofoils had an underlying NACA 634-021 profile and an aspect ratio of 4.3. The sinusoidal leading edge geometries included three amplitudes of 2.5%, 5%, and 12% and two wavelengths of 25% and 50% of the mean chord length. Results revealed that cavitation on the leading edge-modified hydrofoils existed in pockets behind the troughs whereas the baseline hydrofoil produced cavitation along its entire span. Moreover, cavitation on the modified hydrofoils appeared at consistently lower angles of attack than on the baseline hydrofoil.

  16. A benchmark experiment on gas cavitation

    Science.gov (United States)

    Peters, Franz; Honza, Rene

    2014-08-01

    Cavitation research is often a matter of experiments conducted in complex machinery. There, it is extremely difficult to look into one of the most important issues of cavitation which is nucleation. This work investigates gas cavitation under well-defined flow conditions. Nuclei are placed in wall bound cavities and are exposed to a radial gap flow featuring independent pressure and shear stress. A reciprocating bubble generation is achieved. Bubble frequency and size are evaluated which turn out to depend on pressure and wall shear stress. The experiment lends itself to systematic research in cavitation.

  17. Temperature measurements in cavitation bubbles

    Science.gov (United States)

    Coutier-Delgosha, Olivier

    2016-11-01

    Cavitation is usually a nearly isothermal process in the liquid phase, but in some specific flow conditions like hot water or cryogenic fluids, significant temperature variations are detected. In addition, a large temperature increase happens inside the cavitation bubbles at the very end of their collapse, due to the fast compression of the gas at the bubble core, which is almost adiabatic. This process is of primary interest in various biomedical and pharmaceutical applications, where the mechanisms of bubble collapse plays a major role. To investigate the amplitude and the spatial distribution of these temperature variations inside and outside the cavitation bubbles, a system based on cold wires has been developed. They have been tested in a configuration of a single bubble obtained by submitting a small air bubble to a large amplitude pressure wave. Some promising results have been obtained after the initial validation tests. This work is funded by the Office of Naval Research Global under Grant N62909-16-1-2116, Dr. Salahuddin Ahmed & Ki-Han Kim program managers.

  18. Cavitation Generated by Amplitude Modulated HIFU: Investigation on the Inertial Cavitation Threshold

    Science.gov (United States)

    Gilles, Bruno; Saletes, Izella; Béra, Jean-Christophe

    2007-05-01

    An experimental investigation on cavitation threshold was carried out in order to compare monochromatic and dichromatic ultrasound excitations in their ability to generate inertial cavitation on a target. Using a cavitation activity spectral criterion, a precise inertial cavitation threshold could be extracted in every case considered. The results showed that these thresholds could be very different depending on the type of excitation used. More precisely, for the parameters investigated in the present study, the ratio between monochromatic and dichromatic thresholds decreased when cavitation thresholds are increased. The potential application of this study to purely ultrasonic thrombolysis is discussed.

  19. Lung No dules Detection in CT Images Using Gestalt-Based Algorithm

    Institute of Scientific and Technical Information of China (English)

    QIU Shi; WEN Desheng; CUI Ying; FENG Jun

    2016-01-01

    To overcome low accuracy and high false positive of existing computer-aided lung nodules detec-tion. We propose a novel lung nodule detection scheme based on the Gestalt visual cognition theory. The pro-posed scheme involves two parts which simulate human eyes cognition features such as simplicity, integrity and classification. Firstly, lung region was segmented from lung Computed tomography (CT) sequences. Then local three-dimensional information was integrated into the Maximum intensity projection (MIP) images from axial, coronal and sagittal profiles. In this way, lung nodules and vascular are strengthened and discriminated based on pathologic image characteristics of lung nodules. The experimental database includes fifty-three high resolution CT images contained lung nodules, which had been confirmed by biopsy. The experimental results show that, the accuracy rate of the proposed algorithm achieves 91.29%. The proposed frame-work improves performance and computation speed for computer aided nodules detection.

  20. Cavitation instabilities of an inducer in a cryogenic pump

    Science.gov (United States)

    Kim, Dae-Jin; Sung, Hyung Jin; Choi, Chang-Ho; Kim, Jin-Sun

    2017-03-01

    Inducers assist cryogenic pumps to operate safely under cavitation conditions by increasing the pressure of the impeller inlet, but create cavitation instabilities. The use of cryogenic fluids requires special attention because of safety and handling concerns. To examine the cavitation instabilities of a cryogenic pump, two kinds of working fluids, water and liquid oxygen, were employed. The cavitation instabilities were measured with an accelerometer installed on the pump casing. The flow coefficient and the head slightly decrease with decreases in the cavitation number before the cavitation breakdown. These trends are true of both fluids. Several cavitation instabilities were identified with the accelerometer. At lower flow coefficients, super-synchronous rotating cavitation was found in a similar cavitation number range for both fluids. At higher flow coefficients, the cavitation numbers of the cavitation instabilities in the liquid oxygen test are smaller than those of the water test.

  1. Numerical Prediction of Unsteady Behavior of Cavitating Flow on Hydrofoils using Bubble Dynamics Cavitation Model

    Directory of Open Access Journals (Sweden)

    Nur-E- Mostafa

    2016-01-01

    Full Text Available This paper presents a numerical study with pressure-based finite volume method for prediction of non-cavitating and time dependent cavitating flow on hydrofoil. The phenomenon of cavitation is modeled through a mixture model. For the numerical simulation of cavitating flow, a bubble dynamics cavitation model is used to investigate the unsteady behavior of cavitating flow and describe the generation and evaporation of vapor phase. The non-cavitating study focuses on choosing mesh size and the influence of the turbulence model. Three turbulence models such as Spalart-Allmaras, Shear Stress Turbulence (SST k-ω model and Re-Normalization Group (RNG k-ε model with enhanced wall treatment are used to capture the turbulent boundary layer on the hydrofoil surface. The cavitating study presents an unsteady behavior of the partial cavity attached to the foil at different time steps for σ=0.8. Moreover, this study focuses on cavitation inception, the shape and general behavior of sheet cavitation, lift and drag forces for different cavitation numbers. Finally, the flow pattern and hydrodynamic characteristics are also studied at different angles of attack.

  2. Management of pulmonary nodules in head and neck cancer patients - Our experience and interpretation of the British Thoracic Society Guidelines.

    Science.gov (United States)

    Green, Richard; King, Matthew; Reid, Helen; Murchison, John T; Evans, Andrew; Nixon, Iain J

    2017-08-01

    and purpose of the study: The frequency of lung nodules in the head and neck cancer population is unknown, currently the only guidance available recommends following local policy. The aim of this study was to determine the incidence of pulmonary nodules in our head and neck cancer group and interpret the recently updated British Thoracic Society (BTS) Lung Nodule Guidelines in a head and neck cancer setting. 100 patients were diagnosed with head and neck cancer between July 2013-March 2014, clinico-pathological, demographic and radiological data was extracted from the electronic records. Images with lung findings were re-reviewed by a single consultant radiologist for patients with lung pathology on the initial staging CT report. Twenty patients (20%) had discreet pulmonary findings on CT. Eleven (11%) had lung nodules, 6 (6%) had lesions suspicious for metastasis and 3 (3%) had co-incidental bronchogenic primary cancers. These patients were re-imaged between 6 and 18 months and in 1 patient the previously identified 7 mm nodule had progressed to 16 mm at 1 year. There was no set follow up imaging protocol used. The MDT in NHS Lothian has reviewed the BTS guidance and now has a local policy for the management of lung nodules in head and neck cancer patients. Lung Nodules in the head and neck cancer population are common >10%. Higher risk patients with larger nodules should be risk assessed with validated assessment tools. PET-CT has a place in the assessment of lung nodules when risk of malignancy is high. Copyright © 2016 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  3. Cavitation: Cavitation flow. Citations from the NTIS data base

    Science.gov (United States)

    Habercom, G. E., Jr.

    1980-05-01

    Reports on general aspects of cavitating flow are included. A wide range of theoretical, analytical, and experimental information is presented involving mathematical analysis, computer programs, and testing. Topics include marine engineering, hydrodynamic and aerodynamic configurations, symmetric and nonaxisymmetric shapes, and measuring technology. Data is given on surface piercing struts, helical inducers, pumps, liquid metal systems, and venturi tubes. Applications include dam outlets and spillways, vertical conduits, deep rock drilling, heat pipe stability, water entry, and liquid cryogenic systems. Discussions are made of flow characteristics, noise, nucleate boiling, perturbation problems, and allied subjects. This updated bibliography contains 253 abstracts.

  4. Interaction of cavitation bubbles on a wall

    NARCIS (Netherlands)

    Bremond, Nicolas; Arora, Manish; Dammer, Stephan M.; Lohse, Detlef

    2006-01-01

    We report experimental and numerical investigations on the dynamics of the cavitation of bubbles on a solid surface and the interaction between them with the help of controlled cavitation nuclei: hemispherical bubbles are nucleated from hydrophobic microcavities that act as gas traps when the substr

  5. MICRO-COURSE OF CAVITATION EROSION

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhaoyun

    2008-01-01

    By cavitation tests and scanning electron microscope (SEM) microanalysis, the micro- appearance of cavitation samples is studied. It is the first time that the micro-appearance of metals is pursued successfully. According to the changing course of the micro-appearance of metals, the damaging course of cavitation erosion is determined. The destructive way of collapsing bubbles on the metal surface is known. Firstly cavitation pinholes appear on the metal surface, then cracks generate and grow under the action of collapsing bubbles. When cracks connect each other, small pieces are removed from pinhole wall and pinholes develop into cavitation pits. When the previous surface is removed completely, new pinholes are produced again on the new surface. A pinhole is the result of the powerful striking of a micro-liquid jet ejected by a large collapsed bubble near the surface. At some stages, cracks grow in the way of fatigue. The corrosion phenomenon is observed during the cavitation erosion. The cavitation pattern can be used to explain the cavitation pregnancy and the changing regulation of sample surface.

  6. 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.

  7. Reflections on cavitation nuclei in water

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2007-01-01

    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...... 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...... 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...

  8. 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.

  9. SOME REMARKS ON HYDROFOIL CAVITATION

    Institute of Scientific and Technical Information of China (English)

    ARNDT Roger E.A.

    2012-01-01

    This paper reviews numerical and experimental investigations of sheet/cloud cavitation carried out at the St.Anthony Falls Laboratory and at two collaborating facilities (Versuchsanstalt Für Wasserbau,Obernach,Germany and Osaka University,Japan) for more than a decade.Although significant advances have been made in the analysis of this flow several issues are still unresolved.The purpose of this paper is to examine the overall features of the problem,review the progress made to date and suggest avenues for new investigation.

  10. 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.

  11. 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.

  12. Clinical value of calcification density and signs in the diagnosis of lung nodules%探讨肺结节内钙化密度与钙化征象的临床意义

    Institute of Scientific and Technical Information of China (English)

    王秋萍; 金晨望; 邓蕾; 于楠; 强永乾; 冯筠; 郭佑民

    2014-01-01

    目的:研究肺结节内钙化密度与钙化征象对肺结节良恶性预判的性能。方法经病理或随访证实的肺结节240例(良性70例,恶性170例)。利用最大方差和阈值生长法提取肺结节内具有钙化点和钙化密度的像素,并计算每个钙化点的面积(AreaCa)及面积比(Ar)、同一层面内钙化点的总面积(S)及钙化总面积比(Sr)、同一层面内具有钙化密度的总面积(Cs)及钙化密度面积比(Csr)。结果含有钙化密度的结节明显多于含钙化点的结节(49vs26,χ²=8.360,P=0.004),这一现象在恶性结节中尤为突出(良性23vs16;恶性26vs10);良性肺结节钙化点和钙化密度的面积均大于恶性(P=0.000);以钙化点(AreaCa、S、Ar、Sr)对肺结节良恶性预判的诊断性能优秀(Az=0.906),以钙化密度(Cs、Csr)对肺结节性质预判的诊断性能中等(Az=0.727,0.742)。结论在计算机辅助诊断研究中,借鉴医师经验,对肺结节的CT征象直接进行提取、挖掘,或有助于肺结节影像诊断的确立。%Objective Quantitative study was performed on the calcification density and calcification signs in prediction for benign and malignant pulmonary nodules. Methods 240 cases with pulmonary nodules (malignant in 170 and benign in 70) confirmed by pathology or clinical follow-up were included in this study. All cases underwent chest CT examinations. A segmentation algorithm based on maximal variance between-class and region growing was used to extract the pulmonary nodules with calcification signs and the pixel of calcification density. The each calcification area (AreaCa) and area ratio (Ar), the total area of calcification signs within the same level (S) and total area ratio (Sr), the total area of calcification density within same level (Cs), and calcification density ratio (Csr) were calculated. Results The nodules with calcifica

  13. Lung cancer biomarkers in exhaled breath.

    Science.gov (United States)

    Amann, Anton; Corradi, Massimo; Mazzone, Peter; Mutti, Antonio

    2011-03-01

    Lung cancer is the leading cause of cancer-related mortality worldwide. Methods for early detection of lung cancer, such as computerized tomography scanning technology, often discover a large number of small lung nodules, posing a new problem to radiologists and chest physicians. The vast majority of these nodules will be benign, but there is currently no easy way to determine which nodules represent very early lung cancer. Adjuvant testing with PET imaging and nonsurgical biopsies has a low yield for these small indeterminate nodules, carries potential morbidity and is costly. Indeed, purely morphological criteria seem to be insufficient for distinguishing lung cancer from benign nodules at early stages with sufficient confidence, therefore false positives undergoing surgical resection frequently occur. A molecular approach to the diagnosis of lung cancer through the analysis of exhaled breath could greatly improve the specificity of imaging procedures. A biomarker-driven approach to signs or symptoms possibly due to lung cancer would represent a complementary tool aimed at ruling out (with known error probability) rather than diagnosing lung cancer. Volatile and nonvolatile components of the breath are being studied as biomarkers of lung cancer. Breath testing is noninvasive and potentially inexpensive. There is promise that an accurate lung cancer breath biomarker, capable of being applied clinically, will be developed in the near future. In this article, we summarize some of the rationale for breath biomarker development, review the published literature in this field and provide thoughts regarding future directions.

  14. Simulations of Cavitating Cryogenic Inducers

    Science.gov (United States)

    Dorney, Dan (Technical Monitor); Hosangadi, Ashvin; Ahuja, Vineet; Ungewitter, Ronald J.

    2004-01-01

    Simulations of cavitating turbopump inducers at their design flow rate are presented. Results over a broad range of Nss, numbers extending from single-phase flow conditions through the critical head break down point are discussed. The flow characteristics and performance of a subscale geometry designed for water testing are compared with the fullscale configuration that employs LOX. In particular, thermal depression effects arising from cavitation in cryogenic fluids are identified and their impact on the suction performance of the inducer quantified. The simulations have been performed using the CRUNCH CFD[R] code that has a generalized multi-element unstructured framework suitable for turbomachinery applications. An advanced multi-phase formulation for cryogenic fluids that models temperature depression and real fluid property variations is employed. The formulation has been extensively validated for both liquid nitrogen and liquid hydrogen by simulating the experiments of Hord on hydrofoils; excellent estimates of the leading edge temperature and pressure depression were obtained while the comparisons in the cavity closure region were reasonable.

  15. 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.

  16. Simulation and Experimental Study on Cavitating Water Jet Nozzle

    Science.gov (United States)

    Zhou, Wei; He, Kai; Cai, Jiannan; Hu, Shaojie; Li, Jiuhua; Du, Ruxu

    2017-01-01

    Cavitating water jet technology is a new kind of water jet technology with many advantages, such as energy-saving, efficient, environmentally-friendly and so on. Based on the numerical simulation and experimental verification in this paper, the research on cavitating nozzle has been carried out, which includes comparison of the cleaning ability of the cavitating jet and the ordinary jet, and comparison of cavitation effects of different structures of cavitating nozzles.

  17. Numerical simulation of multiphase cavitating flows around an underwater projectile

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The present simulation investigates the multiphase cavitating flow around an underwater projectile.Based on the Homogeneous Equilibrium Flow assumption,a mixture model is applied to simulate the multiphase cavitating flow including ventilated cavitation caused by air injection as well as natural cavitation that forms in a region where the pressure of liquid falls below its vapor pressure. The transport equation cavitating model is applied.The calculations are executed based on a suite of CFD code.The hyd...

  18. Cavitation passive control on immersed bodies

    Science.gov (United States)

    Javadi, Khodayar; Dorostkar, Mohammad Mortezazadeh; Katal, Ali

    2017-03-01

    This paper introduces a new idea of controlling cavitation around a hydrofoil through a passive cavitation controller called artificial cavitation bubble generator (ACG). Cyclic processes, namely, growth and implosion of bubbles around an immersed body, are the main reasons for the destruction and erosion of the said body. This paper aims to create a condition in which the cavitation bubbles reach a steady-state situation and prevent the occurrence of the cyclic processes. For this purpose, the ACG is placed on the surface of an immersed body, in particular, the suction surface of a 2D hydrofoil. A simulation was performed with an implicit finite volume scheme based on a SIMPLE algorithm associated with the multiphase and cavitation model. The modified k-ɛ RNG turbulence model equipped with a modification of the turbulent viscosity was applied to overcome the turbulence closure problem. Numerical simulation of water flow over the hydrofoil equipped with the ACG shows that a low-pressure recirculation area is produced behind the ACG and artificially generates stationary cavitation bubbles. The location, shape, and size of this ACG are the crucial parameters in creating a proper control. Results show that the cavitation bubble is controlled well with a well-designed ACG.

  19. Cavitation passive control on immersed bodies

    Science.gov (United States)

    Javadi, Khodayar; Dorostkar, Mohammad Mortezazadeh; Katal, Ali

    2017-01-01

    This paper introduces a new idea of controlling cavitation around a hydrofoil through a passive cavitation controller called artificial cavitation bubble generator (ACG). Cyclic processes, namely, growth and implosion of bubbles around an immersed body, are the main reasons for the destruction and erosion of the said body. This paper aims to create a condition in which the cavitation bubbles reach a steady-state situation and prevent the occurrence of the cyclic processes. For this purpose, the ACG is placed on the surface of an immersed body, in particular, the suction surface of a 2D hydrofoil. A simulation was performed with an implicit finite volume scheme based on a SIMPLE algorithm associated with the multiphase and cavitation model. The modified k-ɛ RNG turbulence model equipped with a modification of the turbulent viscosity was applied to overcome the turbulence closure problem. Numerical simulation of water flow over the hydrofoil equipped with the ACG shows that a low-pressure recirculation area is produced behind the ACG and artificially generates stationary cavitation bubbles. The location, shape, and size of this ACG are the crucial parameters in creating a proper control. Results show that the cavitation bubble is controlled well with a well-designed ACG.

  20. 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.

  1. 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....

  2. A cavitation aggressiveness index within the Reynolds averaged Navier Stokes methodology for cavitating flows

    Institute of Scientific and Technical Information of China (English)

    KOUKOUVINIS P.; BERGELES G.; GAVAISES M

    2015-01-01

    The paper proposes a methodology within the Reynolds averaged Navier Stokes (RANS) solvers for cavitating flows capable of predicting the flow regions of bubble collapse and the potential aggressiveness to material damage. An aggressiveness index is introduced, called cavitation aggressiveness index (CAI) based on the total derivative of pressure which identifies surface areas exposed to bubble collapses, the index is tested in two known cases documented in the open literature and seems to identify regions of potential cavitation damage.

  3. Water-tolerant legume nodulation.

    Science.gov (United States)

    Capoen, Ward; Goormachtig, Sofie; Holsters, Marcelle

    2010-03-01

    Water-tolerant nodulation is an adaptation of legumes that grow in wet or temporarily flooded habitats. This nodulation mode takes place at lateral root bases via intercellular bacterial invasion in cortical infection pockets. The tropical legume Sesbania rostrata has become a model for the study of the molecular basis of crack entry nodulation compared with root hair curl nodulation. For intercellular invasion, Nodulation Factor (NF) signalling recruits an ethylene-dependent, common Sym gene-independent pathway, leading to local cell death. The NF structure requirements are less stringent than for intracellular invasion in root hairs, which is correlated with a very specific NF-induced calcium spiking signature, presumably necessary for correct gene expression to assemble a functional entry complex in the epidermis.

  4. Pulmonary nodule detection using a cascaded SVM classifier

    Science.gov (United States)

    Bergtholdt, Martin; Wiemker, Rafael; Klinder, Tobias

    2016-03-01

    Automatic detection of lung nodules from chest CT has been researched intensively over the last decades resulting also in several commercial products. However, solutions are adopted only slowly into daily clinical routine as many current CAD systems still potentially miss true nodules while at the same time generating too many false positives (FP). While many earlier approaches had to rely on rather few cases for development, larger databases become now available and can be used for algorithmic development. In this paper, we address the problem of lung nodule detection via a cascaded SVM classifier. The idea is to sequentially perform two classification tasks in order to select from an extremely large pool of potential candidates the few most likely ones. As the initial pool is allowed to contain thousands of candidates, very loose criteria could be applied during this pre-selection. In this way, the chances that a true nodule is falsely rejected as a candidate are reduced significantly. The final algorithm is trained and tested on the full LIDC/IDRI database. Comparison is done against two previously published CAD systems. Overall, the algorithm achieved sensitivity of 0.859 at 2.5 FP/volume where the other two achieved sensitivity values of 0.321 and 0.625, respectively. On low dose data sets, only slight increase in the number of FP/volume was observed, while the sensitivity was not affected.

  5. Cavitation studies on axi-symmetric underwater body with pumpjet propulsor in cavitation tunnel

    Directory of Open Access Journals (Sweden)

    Ch. Suryanarayana

    2010-12-01

    Full Text Available A pumpjet propulsor (PJP was designed for an underwater body (UWB with axi-symmetric configuration. Its performance was predicted through CFD study and models were manufactured. The propulsor design was evaluated for its propulsion characteristics through model tests conducted in a Wind Tunnel (WT. In the concluding part of the study, evaluation of the cavitation performance of the pumpjet was undertaken in a cavitation tunnel (CT. In order to assess the cavitation free operation speeds and depths of the body, cavitation tests of the PJP were carried out in behind condition to determine the inception cavitation numbers for rotor, stator and cowl. The model test results obtained were corrected for full scale Reynolds number and subsequently analyzed for cavitation inception speeds at different operating depths. From model tests it was also found that the cavitation inception of the rotor takes place on the tip face side at higher advance ratios and cavitation shifts towards the suction side as the RPS increases whereas the stator and cowl are free from cavitation.

  6. CT三维最小类内散度多分类支持向量机在肺结节识别中的应用%Application of CT images based 3D minimum within-class scatter multi-class support vector machine in the identification of lung nodules

    Institute of Scientific and Technical Information of China (English)

    范小波; 董莹; 王义云

    2015-01-01

    Objective To analyze the value of CT images based 3D minimum within‐class scatter multi‐class support vector machine (MC‐SVM ) in the identification of lung nodules .Methods During Jan .2012 and Jan .2014 ,a total of 50 cases with pulmonary sarcoidosis were enrolled .Lung CT based 3D matrix pattern volume of interest (VOI) structure were divided into nodules samples and non‐nodule samples .Region of interest (ROI) was extracted by using automatic extraction algorithm ,which was further divided into nodules and non‐nodular ROI .Then the rec‐ognition accuracy ,true positive rate and false positive rate of large‐scale massive training artificial neural network (M TANN) ,fuzzy ′one on one′ multi‐class SVM (matFLSSVM ) ,3D matrix model MC‐SVM and 3D minimum with‐in‐class scatter MC‐SVM were compared by using receiver operating curve (ROC) .Results 3D minimum within‐class scatter MC‐SVM was with the highest recognition accuracy and true positive rate ,and the lowest false positive rate ,compared with the other algorithms (P< 0 .05) .Conclusion 3D minimum within‐class scatter MC‐SVM might be accurate for the recognition if long nodules .%目的:分析 CT 三维最小类内散度多分类支持向量机(MC‐SVM )对肺结节的识别能力及优点。方法选择2012年1月至2014年1月确诊的肺结节病患者50例,根据基于三维矩阵模式的感兴趣体(VOI)的构成,分为结节样和非结节样;采用自动提取算法提取感兴趣区(ROI),分为结节 ROI 和非结节 ROI ;采用受试者工作特征(ROC)曲线比较大规模训练人工神经网络(M TANN)、基于矩阵模式的模糊最小二乘 SVM (matFLSSVM )、三维矩阵模式 MC‐SVM 和三维最小类内散度 MC‐SVM 的识别精度,同时比较各种方法在不同截断点时的真阳性率和假阳性率。结果三维最小类内散度 MC‐SVM 的识别精度、真阳性率均高于其他算法,而假阳

  7. 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....

  8. Automatic detection of large pulmonary solid nodules in thoracic CT images

    Energy Technology Data Exchange (ETDEWEB)

    Setio, Arnaud A. A., E-mail: arnaud.arindraadiyoso@radboudumc.nl; Jacobs, Colin; Gelderblom, Jaap [Diagnostic Image Analysis Group, Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen 6525 GA (Netherlands); Ginneken, Bram van [Diagnostic Image Analysis Group, Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen 6525 GA (Netherlands); Fraunhofer MEVIS, Bremen 28359 (Germany)

    2015-10-15

    Purpose: Current computer-aided detection (CAD) systems for pulmonary nodules in computed tomography (CT) scans have a good performance for relatively small nodules, but often fail to detect the much rarer larger nodules, which are more likely to be cancerous. We present a novel CAD system specifically designed to detect solid nodules larger than 10 mm. Methods: The proposed detection pipeline is initiated by a three-dimensional lung segmentation algorithm optimized to include large nodules attached to the pleural wall via morphological processing. An additional preprocessing is used to mask out structures outside the pleural space to ensure that pleural and parenchymal nodules have a similar appearance. Next, nodule candidates are obtained via a multistage process of thresholding and morphological operations, to detect both larger and smaller candidates. After segmenting each candidate, a set of 24 features based on intensity, shape, blobness, and spatial context are computed. A radial basis support vector machine (SVM) classifier was used to classify nodule candidates, and performance was evaluated using ten-fold cross-validation on the full publicly available lung image database consortium database. Results: The proposed CAD system reaches a sensitivity of 98.3% (234/238) and 94.1% (224/238) large nodules at an average of 4.0 and 1.0 false positives/scan, respectively. Conclusions: The authors conclude that the proposed dedicated CAD system for large pulmonary nodules can identify the vast majority of highly suspicious lesions in thoracic CT scans with a small number of false positives.

  9. Cell mechanics in biomedical cavitation

    Science.gov (United States)

    Wang, Qianxi; Manmi, Kawa; Liu, Kuo-Kang

    2015-01-01

    Studies on the deformation behaviours of cellular entities, such as coated microbubbles and liposomes subject to a cavitation flow, become increasingly important for the advancement of ultrasonic imaging and drug delivery. Numerical simulations for bubble dynamics of ultrasound contrast agents based on the boundary integral method are presented in this work. The effects of the encapsulating shell are estimated by adapting Hoff's model used for thin-shell contrast agents. The viscosity effects are estimated by including the normal viscous stress in the boundary condition. In parallel, mechanical models of cell membranes and liposomes as well as state-of-the-art techniques for quantitative measurement of viscoelasticity for a single cell or coated microbubbles are reviewed. The future developments regarding modelling and measurement of the material properties of the cellular entities for cutting-edge biomedical applications are also discussed. PMID:26442142

  10. Reflections on cavitation nuclei in water

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2007-01-01

    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...... on the surface of particles and bounding walls. Such nuclei can be related to the full range of tensile strengths measured, when differences of experimental conditions are taken into consideration. The absence or presence of contamination on surfaces, as well as the structure of the surfaces, are central...... 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...

  11. Two-Phase Cavitating Flow in Turbomachines

    Directory of Open Access Journals (Sweden)

    Sandor I. Bernad

    2012-11-01

    Full Text Available Cavitating flows are notoriously complex because they are highly turbulent and unsteady flows involving two species (liquid/vapor with a large density difference. These features pose a unique challenge to numerical modeling works. The study briefly reviews the methodology curently employed for industrial cavitating flow simulations using the two-phase mixture model. The two-phase mixture model is evaluated and validated using benchmark problem where experimental data are available. A 3D cavitating flow computation is performed for the GAMM Francis runner. The model is able to qualitatively predict the location and extent of the 3D cavity on the blade, but further investigation are needed to quatitatively assess the accuracy for real turbomachinery cavitating flows.

  12. 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.

  13. Numerical analysis of cavitation within slanted axial-flow pump

    Institute of Scientific and Technical Information of China (English)

    张睿; 陈红勋

    2013-01-01

    In this paper, the cavitating flow within a slanted axial-flow pump is numerically researched. The hydraulic and cavitation performance of the slanted axial-flow pump under different operation conditions are estimated. Compared with the experimental hydraulic performance curves, the numerical results show that the filter-based model is better than the standard k-e model to predict the parameters of hydraulic performance. In cavitation simulation, compared with the experimental results, the proposed numerical method has good predicting ability. Under different cavitation conditions, the internal cavitating flow fields within slanted axial-flow pump are investigated. Compared with flow visualization results, the major internal flow features can be effectively grasped. In order to explore the origin of the cavitation performance breakdown, the Boundary Vorticity Flux (BVF) is introduced to diagnose the cavitating flow fields. The analysis results indicate that the cavitation performance drop is relevant to the instability of cavitating flow on the blade suction surface.

  14. Assessment of Cavitation Erosion with a Multiphase Reynolds-Averaged Navier-Stokes Method

    NARCIS (Netherlands)

    Li, Z.R.

    2012-01-01

    Cavitation erosion is one of the remarkable catastrophic consequences of cavitation. Predicting the cavitation aggressiveness quantitatively and predicting the most probable location of cavitation erosion are complex problems that currently still motivate an important amount of basic and applied res

  15. Diagnostic value of diffuse and peripheral lung lesions by transbronchial lung biopsy

    Institute of Scientific and Technical Information of China (English)

    石志红; 魏霞; 卫小红; 朱柏

    2008-01-01

    Objective To evaluate the diagnostic value of transbronchial lung biopsy(TBLB)via bronchoscope for lung diffuse lesions and peripheral pulmonary lesions.Methods The results of TBLB were retrospectively analyzed from 256 diagnoses of unknown patients with lung diffuse lesions or peripheral lung lesions.Results Eighty-nine final diagnosis cases via TBLB only once,the diagnostic rate of double lung diffuse lesions was the highest,[51.06%(24/47)],local non-nodule lesions,nodule lesions,cavity lesions were 33.33...

  16. Automatic detection of spiculation of pulmonary nodules in computed tomography images

    Science.gov (United States)

    Ciompi, F.; Jacobs, C.; Scholten, E. T.; van Riel, S. J.; W. Wille, M. M.; Prokop, M.; van Ginneken, B.

    2015-03-01

    We present a fully automatic method for the assessment of spiculation of pulmonary nodules in low-dose Computed Tomography (CT) images. Spiculation is considered as one of the indicators of nodule malignancy and an important feature to assess in order to decide on a patient-tailored follow-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 the two categories, information on morphology is captured by sampling intensity profiles along circular patterns on spherical surfaces centered on the nodule, in a multi-scale fashion. Each intensity profile is interpreted as a periodic signal, where the Fourier transform is applied, obtaining a spectrum. 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 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.

  17. Primary Intrapulmonary Thymoma Presenting as a Solitary Pulmonary Nodule

    Science.gov (United States)

    Jung, Woohyun; Kang, Chang Hyun; Kim, Young Tae; Park, In Kyu

    2017-01-01

    Primary intrapulmonary thymoma (PIT) is a very rare lesion of uncertain pathogenesis. PIT should be considered when the histopathological appearance of a lung tumor shows features that are uncommon but similar to those of a thymoma. In this case report, we discuss the case of a 59-year-old female with a solitary pulmonary nodule that was confirmed to be PIT on the basis of pathological tests. Treatment with complete resection showed good results. PMID:28180106

  18. Synchronized passive imaging of single cavitation events

    Science.gov (United States)

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Chauvet, Daurian; Boch, Anne-Laure; Fink, Mathias; Tanter, Mickaël

    2011-09-01

    Passive cavitation detection techniques are usually of relatively low sensitivity to single cavitation events. Moreover, a single-element transducer is generally used, so that the spatial localization of these cavitation events is not possible, or is limited to the probing volume. To both detect and localize single cavitation events over an extended volume, the following experimental set-up has been used and validated: cavitation is induced with a focused single-element transducer (mean frequency 660 kHz, f♯ = 1) driven by a high power (up to 5 kW) electric burst of a few cycles, and the acoustic emission of the bubbles is recorded on a standard linear array (4-7 MHz), mounted on the side of the single element to probe its focal spot. Both the frequencies and the geometry used are appropriate to in vivo implementation. The recording of ultrasonic radio-frequency (RF) data was performed simultaneously on 64 channels of the array and was synchronized with the pulsed excitation. A single cavitation event results in a high frequency and coherent wave front on the RF data. Thanks to synchronization, these RF data are beam-formed to localize the event with a axial resolution of 0.3 mm. A small number of discrete events could also be separated with this method. Besides, B-mode images obtained with the linear array prior to passive detection allowed the positioning of the events within the tissue structure. This technique has been used first ex vivo on freshly harve pig and sheep thigh muscle: with a two cycle excitation, a 9 MPa cavitation threshold was found. Cavitation detection was also achieved in vivo with a five cycle burst excitation in sheep thigh muscle for a peak acoustic pressure of 11MPa. This technique could provide useful information in order to better understand, control and monitor the initiation phase of the histotripsy process.

  19. The incidental pulmonary nodule in a child. Part 2: Commentary and suggestions for clinical management, risk communication and prevention

    Energy Technology Data Exchange (ETDEWEB)

    Westra, Sjirk J. [Massachusetts General Hospital, Division of Pediatric Radiology, Boston, MA (United States); Thacker, Paul G. [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Podberesky, Daniel J. [Nemours Children' s Hospital, Department of Radiology, Orlando, FL (United States); Lee, Edward Y. [Boston Children' s Hospital, Department of Pediatric Radiology, Boston, MA (United States); Iyer, Ramesh S. [Seattle Children' s Hospital, Department of Radiology, Seattle, WA (United States); Hegde, Shilpa V. [Arkansas Children' s Hospital, Department of Radiology, Little Rock, AR (United States); Guillerman, R.P. [Texas Children' s Hospital, Department of Radiology, Houston, TX (United States); Mahani, Maryam Ghadimi [University of Michigan Health System, Section of Pediatric Radiology, C. S. Mott Children' s Hospital, Department of Radiology, Ann Arbor, MI (United States)

    2015-05-01

    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.)

  20. AN ATTRIBUTION OF CAVITATION RESONANCE: VOLUMETRIC OSCILLATIONS OF CLOUD

    Institute of Scientific and Technical Information of China (English)

    ZUO Zhi-gang; LI Sheng-cai; LIU Shu-hong; LI Shuang; CHEN Hui

    2009-01-01

    In order to further verify the proposed theory of cavitation resonance, as well as to proceed the investigations into microscopic level, a series of studies are being carried out on the Warwick venturi. The analysis of the oscillation characteristics of the cavitation resonance has conclusively verified the macro-mechanism proposed through previous studies on other cavitating flows by the authors. The initial observations using high-speed photographic approach have revealed a new attribution of cavitation resonance. That is, the volumetric oscillation of cavitation cloud is associated with the cavitation resonance, which is a collective behaviour of the bubbles in the cloud.

  1. Lung nodule detection based on Dynamic Multiple Classifiers Selection ensemble algorithm%动态多分类器集成在肺结节辅助检测中的应用

    Institute of Scientific and Technical Information of China (English)

    韩妍妍; 冯筠; 崔鑫; 王秋萍

    2012-01-01

    针对肺结节病灶数据具有多样性及异质性特点,提出了动态多分类器选择集成算法(Dynamic Multiple Classifiers Selection,DMCS),将特征空间随机划分为若干特征子集,针对每个特征子集样本分布不同,对不同的特征子集选择适合的基分类器,最后进行集成学习.实验表明,该算法比目前有代表性的肺结节检测病灶分类算法具有更好的稳定性和检测性能.%A novel approach based on Dynamic Multiple Classifiers Selection(DMCS) ensemble algorithm is proposed based on the characteristics of diversity and inhomogeneity of the nodule lesions. The feature space is randomly divided into a number of feature sub-sets. Specifically, for different kinds of subset, more appropriate base classifier is selected based on their distributions. Then the results of the classifiers are ensembled for final decision. The experimental results demonstrate that the proposed algorithm achieves better per-formance than the typical and traditional nodule detection approaches.

  2. Numerical and Experimental Studies of Cavitation Behavior in Water-Jet Cavitation Peening Processing

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2013-01-01

    Full Text Available Water-jet cavitation peening (WCP is a new technology for the surface modification of metallic materials. The cavitation behavior in this process involves complex and changeable physics phenomena, such as high speed, high pressure, multiple phases, phase transition, turbulence, and unstable features. Thus, the cavitation behavior and impact-pressure distribution in WCP have always been key problems in this field. Numerous factors affect the occurrence of cavitation. These factors include flow-boundary conditions, absolute pressure, flow velocity, flow viscosity, surface tension, and so on. Among these factors, pressure and vapor fraction are the most significant. Numerical simulations are performed to determine the flow-field characteristics of both inside and outside the cavitating nozzle of a submerged water jet. The factors that influence the cavitation intensity of pressure are simulated. Fujifilm pressure-sensitive paper is used to measure the distribution of impact pressure along the jet direction during the WCP process. The results show that submerged cavitation jets can induce cavitation both inside and outside a conical nozzle and a convergent-divergent nozzle when the inlet pressure is 32 MPa. Moreover, the shock wave pressure induced by the collapse of the bubble group reaches up to 300 MPa.

  3. Model of Light Scattering in Cavitation Area

    Directory of Open Access Journals (Sweden)

    S. P. Skvortsov

    2015-01-01

    Full Text Available The offered work presents analysis of extinction mechanisms and justification of light scattering model in ultrasonic cavitation area to justify a control method of ultrasonic cavitation through its optical sounding by low-intensity laser radiation and through photo-detector record of last radiation.The analysis of the extinction mechanisms has shown that the most essential mechanism causing a change of the transmission coefficient with time is dispersion on pulsating cavitation bubbles. Other extinction mechanisms lead to the time-constant reduction of last radiation intensity and can be taken into consideration by normalizing a recorded transmission coefficient for a previously measured liquid transmission coefficient when there is no cavitation.The feature of light scattering on the cavitation bubbles is primary dispersion in a forward direction that is connected with great values of bubbles radius from units to hundreds of micrometers. In case of single bubbles, dispersion can be described by Mi's theory, and, as to the cavitation area, it is reasonable to use the theory of V. Tversky for multiple light scattering. Thus, dispersion section, according to the paradox of extinction, can be considered to be equal to doubled geometrical section of a bubble. With increasing bubble radius the transmission coefficient monotonically decreases. So, the law of bubble pulsations and the model of light scattering define the law of changing transmission coefficient.Therefore, the cavitation area with its optical sounding acts as a peculiar opto-acoustic modulator. Thus, the demodulated signal of a photo-detector comprises information on pulsations of bubbles.The paper examines the influence of cavitation area thickness and bubbles concentration on the transmission coefficient. It shows a type of transmission coefficient dependence on the radius of cavitation bubbles.The optical sounding method is attractive because it allows us to obtain data on the

  4. Numerical analysis of the interactions of sheet cavitation and cloud cavitation around a hydrofoil

    Science.gov (United States)

    Pan, D. Z.; Zhang, D. S.; Wang, H. Y.; Shi, W. D.; Shi, L.

    2015-01-01

    Partial cavitation and cloud cavitation on NACA66(MOD) was studied based on PANS turbulence model combined with the Zwart cavitation model. The results agree well with the data from the experimental results. The existence of a kind of unsteady characteristics of cloud cavitation is analysed in details. The reasons for the inhibition mechanism of the sheet cavitation are discussed. Pressure shock wave occurs near the tailing edge of the hydrofoil when the collapse of cloud is so large leading to great influence on the cavity closed to the leading edge. The evolution of the pressure peak and its propagation toward the leading edge were investigated through the study of the time domain signal of the monitor points along the streamline of flow. Finally, the propagation of the pressure wave on the suction side was further investigated through analysing the spatial-time history of wall pressure.

  5. Pulmonary nodules and metastases in colorectal cancer

    DEFF Research Database (Denmark)

    Nordholm-Carstensen, Andreas

    2016-01-01

    Patients with newly diagnosed colorectal cancer (CRC) are subjected to a preoperative thoraco-abdominal CT scan to determine the cancer stage. This staging is of relevance with regard to treatment and prognosis. About 20% of the patients have distant metastatic spread at the time of diagnosis, i...... detected in 7.5% of the patients and in 37% of these cases the metastatic spread was confined to the lungs. The prevalence of SPCM increased with the implementation of thoracic CT in CRC staging. SPCM impaired survival significantly and was associated with increasing age and rectal cancer. Resection...... is minimal. Furthermore, the current staging practice is complicated by a high number of incidental findings on the thoracic CT, so-called indeterminate pulmonary nodules (IPN). IPN can potentially represent SPCM. The purpose of this thesis was to estimate the prevalence, characteristics and clinical...

  6. Numerical prediction of impact force in cavitating flows

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, B [Department of Thermal Engineering, State Key Laboratory of Hydroscience and Engineering, Tsinghua Univeersity, Beijing, 100084 (China); Wang, H, E-mail: bszhu@mail.tsinghua.edu.c [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China)

    2010-08-15

    An analytical method including a macroscopic cavitation model based on the homogeneous flow theory and a microscopic cavitation model based on the bubble dynamic was proposed for the prediction of the impact force caused by cavitation bubbles collapse in cavitating flows. A Large Eddy Simulation (LES) solver incorporated the macroscopic cavitation model was applied to simulate the unsteady cavitating flows. Based on the simulated flow field, the evolution of the cavitation bubbles was determined by a microscopic cavitation model from the resolution of a Rayleigh-Plesset equation including of the effects of the surface tension, the viscosity and compressibility of fluid, thermal conduction and radiation, the phase transition of water vapor at interface and chemical reactions. The cavitation flow around a hydrofoil was simulated to validate the macroscopic cavitation model. A good quantitative agreement was obtained between the prediction and the experiment. The proposed analytical method was applied to predict the impact force at cavitation bubbles collapse on a KT section in cavitating flows. It was found that the shock pressure caused by cavitation bubble collapse is very high. The impact force was predicted accurately comparing with the experimental data.

  7. Evaluation of Pulmonary Nodules: Clinical Practice Consensus Guidelines for Asia.

    Science.gov (United States)

    Bai, Chunxue; Choi, Chang-Min; Chu, Chung Ming; Anantham, Devanand; Chung-Man Ho, James; Khan, Ali Zamir; Lee, Jang-Ming; Li, Shi Yue; Saenghirunvattana, Sawang; Yim, Anthony

    2016-10-01

    American College of Chest Physicians (CHEST) clinical practice guidelines on the evaluation of pulmonary nodules may have low adoption among clinicians in Asian countries. Unique patient characteristics of Asian patients affect the diagnostic evaluation of pulmonary nodules. The objective of these clinical practice guidelines was to adapt those of CHEST to provide consensus-based recommendations relevant to practitioners in Asia. A modified ADAPTE process was used by a multidisciplinary group of pulmonologists and thoracic surgeons in Asia. An initial panel meeting analyzed all CHEST recommendations to achieve consensus on recommendations and identify areas that required further investigation before consensus could be achieved. Revised recommendations were circulated to panel members for iterative review and redrafting to develop the final guidelines. Evaluation of pulmonary nodules in Asia broadly follows those of the CHEST guidelines with important caveats. Practitioners should be aware of the risk of lung cancer caused by high levels of indoor and outdoor air pollution, as well as the high incidence of adenocarcinoma in female nonsmokers. Furthermore, the high prevalence of granulomatous disease and other infectious causes of pulmonary nodules need to be considered. Therefore, diagnostic risk calculators developed in non-Asian patients may not be applicable. Overall, longer surveillance of nodules than those recommended by CHEST should be considered. TB in Asia favors lesser reliance on PET scanning and greater use of nonsurgical biopsy over surgical diagnosis or surveillance. Practitioners in Asia are encouraged to use these adapted consensus guidelines to facilitate consistent evaluation of pulmonary nodules. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  8. [Genetic resources of nodule bacteria].

    Science.gov (United States)

    Rumiantseva, M L

    2009-09-01

    Nodule bacteria (rhizobia) form highly specific symbiosis with leguminous plants. The efficiency of accumulation of biological nitrogen depends on molecular-genetic interaction between the host plant and rhizobia. Genetic characteristics of microsymbiotic strains are crucial in developing highly productive and stress-resistant symbiotic pairs: rhizobium strain-host plant cultivar (species). The present review considers the issue of studying genetic resources of nodule bacteria to identify genes and their blocks, responsible for the ability of rhizobia to form highly effective symbiosis in various agroecological conditions. The main approaches to investigation of intraspecific and interspecific genetic and genomic diversity of nodule bacteria are considered, from MLEE analysis to the recent methods of genomic DNA analysis using biochips. The data are presented showing that gene centers of host plants are centers of genetic diversification of nodule bacteria, because the intraspecific polymorphism of genetic markers of the core and the accessory rhizobial genomes is extremely high in them. Genotypic features of trapped and nodule subpopulations of alfalfa nodule bacteria are discussed. A survey of literature showed that the genomes of natural strains in alfalfa gene centers exhibit significant differences in genes involved in control of metabolism, replication, recombination, and the formation of defense response (hsd genes). Natural populations of rhizobia are regarded as a huge gene pool serving as a source of evolutionary innovations.

  9. Cavitation Measurement during Sonic and Ultrasonic Activated Irrigation

    NARCIS (Netherlands)

    Macedo, Ricardo; Verhaagen, Bram; Rivas, David Fernandez; Versluis, Michel; Wesselink, Paul; van der Sluis, Luc

    Introduction: The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods: The amount of cavitation generated around several endodontic instruments was

  10. 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.

    Application of hydrodynamic cavitation for disinfection of water is gaining momentum, as it provides environmentally and economically sound options. In this effort, the effect of cavitating conditions created by differential pump valve opening...

  11. 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...

  12. DETECTION OF CAVITATION IN CENTRIFUGAL PUMP BY VIBRATION METHODS

    Institute of Scientific and Technical Information of China (English)

    NI Yongyan; YUAN Shouqi; PAN Zhongyong; YUAN Jianping

    2008-01-01

    For the purpose of detecting the cavitation of centrifugal pump onsite and real time, the vibration signals on varied operation conditions of both cavitation and non-cavitation obtained through acceleration sensors were analyzed. When cavitation occurs, the cavities near the leading edge of the blade will appear periodic oscillating, which will induce quasi-synchronous vibration. The frequency of the quasi-synchronous vibration symmetrically appears on the two sides of the blade passing frequency, by which the cavitation incipiency can be detected. During the developing process of the cavitation, as the severe complexity of the unsteady flow, it is very difficult to detect the development of cavitation by classical analysis methods. Fractal method of Higuchi is successfully used for detecting the incipiency, fully development of cavitation and the development between them.

  13. ‘I still don’t know diddly’: a longitudinal qualitative study of patients’ knowledge and distress while undergoing evaluation of incidental pulmonary nodules

    OpenAIRE

    Sullivan, Donald R.; Golden, Sara E.; Ganzini, Linda; Hansen, Lissi; Slatore, Christopher G.

    2015-01-01

    Background: Hundreds of thousands of incidental pulmonary nodules are detected annually in the United States, and this number will increase with the implementation of lung cancer screening. The lengthy period for active pulmonary nodule surveillance, often several years, is unique among cancer regimens. The psychosocial impact of longitudinal incidental nodule follow-up, however, has not been described. Aims: We sought to evaluate the psychosocial impact of longitudinal follow-up of incidenta...

  14. Diagnostic value of diffuse and peripheral lung lesions by transbronchial lung biopsy

    Institute of Scientific and Technical Information of China (English)

    Shi Zhihong; Wei Xia; Wei Xiaohong; Zhu Bo

    2008-01-01

    Objective To evaluate the diagnostic value of transbronchial lung biopsy (TBLB) via bronchoscope for lung diffuse lesions and peripheral pulmonary lesions. Methods The results of TBLB were retrospectively analyzed from 256 diagnoses of unknown patients with lung diffuse lesions or peripheral lung lesions. Results Eighty-nine final diagnosis cases via TBLB only once, the diagnostic rate of double lung diffuse lesions was the highest, [51.06% (24/47)], local non-nodule lesions, nodule lesions, cavity lesions were 33.33%(23/69), 29.91%(35/117), and 28.57%(4/14), respectively. Among 24 diagnostic cases of double lung diffuse lesions, there were 6 cases of pneumonia of pulmonary tuberculosis, 9 cases of lung carcinoma, 7 cases of adenecarcinoma; 6 cases of pneumonia, 2 cases of fungous infection, and 1 case of lung hemosiderusis. The diagnostic yield about 58 cases of local lesions was low, among which non-nodule lesions accounted for 33.33% and nodule lesions accounted for 29.91%. In 89 cases of peripheral lung lesions with histological diagnosis, lung carcinoma and pulmonary tuberculosis were frequent diseases, which accounted for 86.52%. Conclusion TBLB is a reliable, safe, effective and repeatable operation method in diagnosis of lung diffuse lesions and peripheral pulmonary lesions.

  15. THE WALL EFFECT ON VENTILATED CAVITATING FLOWS IN CLOSED CAVITATION TUNNELS

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin; LU Chuan-jing; LI Jie; PAN Zhan-cheng

    2008-01-01

    For ventilated cavitating flows in a closed water tunnel, the wall effect may exert an important influence on cavity shape and hydrodynamics. An isotropic mixture multiphase model was established to study the wall effect based on the RANS equations,coupled with a natural cavitation model and the RaNG k-ε turbulent model. The governing equations were discrctized using the finite volume method and solved by the Gauss-Seidel linear equation solver on the basis of a segregation algorithm. The algebraic multigrid approach was carried through to accelerate the convergence of solution. The steady ventilated cavitating flows in water tunnels of different diameter were simulated for a conceptual underwater vehicle model which had a disk cavitator. It is found that the choked cavitation number derived is close to the approximate solution of natural cavitating flow for a 3-D disk. The critical ventilation rate falls with decreasing diameter of the water tunnel. However, the cavity size and drag coefficient are rising with the decrease in tunnel diameter for the same ventilation rate, and the cavity size will be much different in water tunnels of different diameter even for the same ventilated cavitation number.

  16. 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.

  17. Noise Caused by Cavitating Butterfly and Monovar Valves

    Science.gov (United States)

    HASSIS, H.

    1999-08-01

    An experimental study of the effects of cavitation was carried out through an analysis of cavitating Butterfly and Monovar values. Focus is particularly placed on both unsteady pressure and acoustic pressure fluctuations. In this paper, the effects of cavitation on local fluctuation pressure (turbulence), acoustic propagation (damping and sound velocity), resonance frequencies and level of noise are presented.

  18. Static and Transient Cavitation Threshold Measurements for Mercury

    Energy Technology Data Exchange (ETDEWEB)

    Moraga, F.; Taleyarkhan, R.P.

    1999-11-14

    Transient and static cavitation thresholds for mercury as a function of the cover gas (helium or air), and pressure are reported. Both static and transient cavitation onset pressure thresholds increase linearly with cover gas pressure. Additionally, the cavitation thresholds as a function of dissolved gases were also measured and are reported.

  19. Real-time two-dimensional imaging of microbubble cavitation

    Science.gov (United States)

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

    2012-10-01

    Ultrasound cavitation of microbubble contrast agents has a potential for 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 cavitation) and intensity in and around a treatment area. Acoustic Passive Cavitation Detectors (PCDs) have been used but do not provide spatial information. This paper presents a prototype of a 2D cavitation imager capable of producing images of the dominant cavitation state and intensity in a region of interest at a frame rate of 0.6Hz. The system is based on a modified ultrasound scanner (iE33, Philips) with a sector imaging probe (S5-1). Cavitation imaging is based on the spectral analysis of the acoustic signal radiated by the cavitating microbubbles: ultraharmonics of the excitation frequency indicate stable cavitation, while noise bands indicate inertial cavitation. The system demonstrates the capability to robustly identify stable and inertial cavitation thresholds of Definity microbubbles (Lantheus) in a vessel phantom through 3 ex-vivo human temporal bones, as well as to spatially map cavitation activities.

  20. Peripheral pulmonary nodules: Relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF expression

    Directory of Open Access Journals (Sweden)

    Cheng Xiao-Ling

    2008-06-01

    Full Text Available Abstract Background The aim of this study is to investigate the relationship between16-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF (vascular endothelial growth factor expression in patients with benign and malignant pulmonary nodules, and differential diagnosis between benign and malignant pulmonary nodules. Methods Sixty-four patients with benign and malignant pulmonary nodules underwent 16-slice spiral CT perfusion imaging. The CT perfusion imaging was analyzed for TDC (time density curve, perfusion parametric maps, and the respective perfusion parameters. Immunohistochemical findings of MVD (microvessel density measurement and VEGF expression was evaluated. Results The shape of the TDC of peripheral lung cancer was similar to those of inflammatory nodule. PH (peak height, PHpm/PHa (peak height ratio of pulmonary nodule to aorta, BF (blood flow, BV (blood volume value of peripheral lung cancer and inflammatory nodule were not statistically significant (all P > 0.05. Both showed significantly higher PH, PHpm/PHa, BF, BV value than those of benign nodule (all P 0.05. In the case of adenocarcinoma, BV, BF, PS, PHpm/PHa, and MVD between poorly and well differentiation and between poorly and moderately differentiation were statistically significant (all P 0.05. PH, PHpm/PHa, BV, and PS of benign nodule were significantly lower than those of peripheral lung cancer (all P Conclusion Multi-slice spiral CT perfusion imaging closely correlated with tumor angiogenesis and reflected MVD measurement and VEGF expression. It provided not only a non-invasive method of quantitative assessment for blood flow patterns of peripheral pulmonary nodules but also an applicable diagnostic method for peripheral pulmonary nodules.

  1. Seamless insertion of real pulmonary nodules in chest CT exams

    Science.gov (United States)

    Pezeshk, Aria; Sahiner, Berkman; Zeng, Rongping; Wunderlich, Adam; Chen, Weijie; Petrick, Nicholas

    2014-03-01

    The availability of large medical image datasets is critical in many applications such as training and testing of computer aided diagnosis (CAD) systems, evaluation of segmentation algorithms, and conducting perceptual studies. However, collection of large repositories of clinical images is hindered by the high cost and difficulties associated with both the accumulation of data and establishment of the ground truth. To address this problem, we are developing an image blending tool that allows users to modify or supplement existing datasets by seamlessly inserting a real lesion extracted from a source image into a different location on a target image. In this study we focus on the application of this tool to pulmonary nodules in chest CT exams. We minimize the impact of user skill on the perceived quality of the blended image by limiting user involvement to two simple steps: the user first draws a casual boundary around the nodule of interest in the source, and then selects the center of desired insertion area in the target. We demonstrate examples of the performance of the proposed system on samples taken from the Lung Image Database Consortium (LIDC) dataset, and compare the noise power spectrum (NPS) of blended nodules versus that of native nodules in simulated phantoms.

  2. Modelling vaporous cavitation on fluid transients

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    A comprehensive study of the problem of modelling vaporous cavitation in transmission lines is presented. The two-phase homogeneous equilibrium vaporous cavitation model which has been developed is compared with the conventional column separation model. The latter predicts unrealistically high pressure spikes because of a conflict arising from the prediction of negative cavity sizes if the pressure is not permitted to fall below the vapour pressure, or the prediction of negative absolute pressures if the cavity size remains positive. This is verified by a comparison of predictions with previously published experimental results on upstream, midstream and downstream cavitation. The new model has been extended to include frequency-dependent friction. The characteristics predicted by the frequency-dependent friction model show close correspondence with experimental data.

  3. Cavitation erosion of NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, A. [Powertech Labs. Inc., Surrey, British Columbia (Canada)]|[Univ. of British Columbia (Canada). Metals and Materials Engineering Dept.; Salvi, R. [Univ. of British Columbia (Canada). Metals and Materials Engineering Dept.; Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1999-02-01

    Vibratory cavitation erosion tests were carried out on as-cast NiAl intermetallic compounds containing 46.5 to 62.1 at. pct Ni. The erosion rate decreased with increasing nickel content by over two orders of magnitude, from a high of 16.4 to 0.11 mg{center_dot}h{sup {minus}1}. These low erosion rates exhibited by the nickel-rich alloys containing 58 and 62.1 at. pct Ni, the interruptions in their mass loss with time, and the unusual effects associated with surface finish and intensity of cavitation were found to be associated with the stress-induced martensitic transformation. Alloys containing 58 to 62 at. pct Ni have the potential for use as materials for the cavitation protection of hydraulic machinery.

  4. Fundamental studies on cavitation melt processing

    Science.gov (United States)

    Tzanakis, I.; Hodnett, M.; Lebon, G. S. B.; Eskin, D. G.; Pericleous, K.

    2016-05-01

    The application of ultrasound to industrial casting processes has attracted research interest during the last 50 years. However, the transfer and scale-up of this advanced and promising technology to industry has been hindered by difficulties in treating large volumes of liquid metal due to the lack of understanding of certain fundamentals. In the current study experimental results on ultrasonic processing in deionised water and in liquid aluminium (Al) are reported. Cavitation activity was determined in both liquid environments and acoustic pressures were successfully measured using an advanced high-temperature cavitometer sensor. Results showed that highest cavitation intensity in the liquid bulk is achieved at lower amplitudes of the sonotrode tip than the maximum available, suggesting nonlinearity in energy transfer to the liquid, while the location of the sonotrode is seen to substantially affect cavitation activity within the liquid. Estimation of real-time acoustic pressures distributed inside a crucible with liquid Al was performed for the first time.

  5. Analogy between fluid cavitation and fracture mechanics

    Science.gov (United States)

    Hendricks, R. C.; Mullen, R. L.; Braun, M. J.

    1983-01-01

    When the stresses imposed on a fluid are sufficiently large, rupture or cavitation can occur. Such conditions can exist in many two-phase flow applications, such as the choked flows, which can occur in seals and bearings. Nonspherical bubbles with large aspect ratios have been observed in fluids under rapid acceleration and high shear fields. These bubbles are geometrically similar to fracture surface patterns (Griffith crack model) existing in solids. Analogies between crack growth in solid and fluid cavitation are proposed and supported by analysis and observation (photographs). Healing phenomena (void condensation), well accepted in fluid mechanics, have been observed in some polymers and hypothesized in solid mechanics. By drawing on the strengths of the theories of solid mechanics and cavitation, a more complete unified theory can be developed.

  6. Sonic effervescence: A tutorial on acoustic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Apfel, R.E. [Yale University, New Haven, Connecticut 06520-8286 (United States)

    1997-03-01

    This article on acoustic cavitation is a revision of a tutorial lecture presented at the Acoustical Society of America meeting in Austin, Texas, on 28 November 1994. The general approach adopted here differs from a review article in stressing the overarching themes that come under the category of acoustic cavitation, rather than being an encyclopedic reference on the topic. When possible, specific order-of-magnitude estimates have been given so that the reader can better understand the particular phenomena being described. The basic physics is discussed, and applications are reviewed with the goal of putting them in a useful context. {copyright} {ital 1997 Acoustical Society of America.}

  7. Dynamics of cavitating cascades. [transfer functions

    Science.gov (United States)

    Brennen, C. E.; Acosta, A. J.

    1980-01-01

    The unsteady dynamics of cavitating cascades and inducer pumps were studied with a view to understanding (and possibly predicting) the dynamic characteristics of these devices. The chronology of the research is summarized as well as the final conculsions for each task. The construction of a dynamic pump test facility and its use in making experimental measurements of the transfer function is described as well as tests conducted using a scale model of the low pressure liquid oxygen turbopump inducer in the shuttle main engine. Auto-oscillation and unsteady inlet flow characteristics are discussed in addition to blade cavity influence and bubbly cavitation.

  8. Cavitation wear resistance of engine bearing materials

    Science.gov (United States)

    Rac, Aleksandar

    1994-04-01

    The resistance to cavitation erosion of aluminum alloy, and cast and sinte-red lead-bronze, materials which are most frequently used for engine bearings, has been evaluated. The tests were carried out in motor oil at a temperature of 80 C, using a magnetostrictive vibratory tester (20 kHz). The results showed that the cavitation erosion resistance was the greatest in cast lead-bronze. On the contrary, sintered lead-bronze, though of the same chemical composition, had the greatest erosion rate. Additionally, the investigation of the overlay plated bearings showed the overlay was nonresistive to this type of wear.

  9. 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.

  10. Approaches to juxta-pleural nodule detection in CT images within the MAGIC-5 Collaboration

    Science.gov (United States)

    de Nunzio, G.; Massafra, A.; Cataldo, R.; de Mitri, I.; Peccarisi, M.; Fantacci, M. E.; Gargano, G.; Lopez Torres, E.

    2011-08-01

    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 α-hull and morphological closing are compared, proving the higher sensitivity of the former, which also appears computationally less heavy.

  11. Effect of cavitation on comminution of mica powder

    Institute of Scientific and Technical Information of China (English)

    ChuwenGuo; LinshengLiu; 等

    2002-01-01

    The cavitation abrasive water jet was used in the comminution of mica.By applying a cavitation nozzle in the abrasive water jet system to enhance the effect of cavitation and friction,better comminution results were obtained.The JME-200CX transmission electron microscope was used for observing the size distribution of particles.As using cavitation abrasive water jet,the relative comminution effect is raised by more than 25% compared with using abrasive water jet oly.It can be concluded that the effect of cavitation is much more significant than that of impacting in the comminution of mica.

  12. Effect of cavitation on comminution of mica powder

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The cavitation abrasive water jet was used in the comminution of mica. By applying a cavitation nozzle in the abrasive water jet system to enhance the effect of cavitation and friction, better comminution results were obtained. The JME-200CX transmission electron microscope was used for observing the size distribution of particles. As using cavitation abrasive water jet, the relative comminution effect is raised by more than 25% compared with using abrasive water jet only. Itcan be concluded that the effect of cavitation is much more significant than that of impacting in the comminution of mica.

  13. Computed Tomography Guided Hook-wire Precise Localization and Minimally Invasive Resection of Pulmonary Nodules

    Directory of Open Access Journals (Sweden)

    Tong WANG

    2015-11-01

    Full Text Available Background and objective Localization of pulmonary ground glass nodule is the technical difficulty of minimally invasive operation resection. The aim of this study is to evaluate the value of computed tomography (CT-guided Hook-wire precise localization in resection of pulmonary nodules by video-assisted thoracoscopic surgery (VATS as well as to discuss the necessity and feasibility of surgical resection of GGOs through a minimally invasive approach. Methods CT-guided Hook-wire precise localization and wedge resection was done on 25 cases with 26 pulmonary nodules by VATS from May 2013 to June 2015. The efficacy of localization was evaluated in terms of procedure time, VATS success rate, and associated complications of localization. Results All the 26 pulmonary nodules (6 solid nodules and 20 GGOs of 25 patients (10 males and 15 females were preoperatively detected and localized with Hook-wire under CT guidance. Nodule diameters ranged from 5 mm-20 mm (mean: 8 mm. The distance of lung lesions from the nearest pleural surfaces ranged within 5 mm-30 mm (mean: 14 mm. All resections of lesions guided by the Hook-wire were successfully performed by VATS (success rate: 100%. The mean procedure time for the CT-guided Hook-wire localization was 10 min (range: 5 min-10 min. The mean procedure time for VATS wedge resection was 20 min (range: 15 min-40 min. The mean hospital time was 4 d (range: 3 d-6 d. The major complication of CT-guided Hook-wire localization was mild pneumothorax in 4 patients, but no one needed chest tube drainage. Wedge resection was performed successfully in all cases. The dislocation of Hook-wire was found in only one patient during the operation, but the lesion was still successfully resected under VATS. Results of pathological examination of 16 mGGOs revealed 8 primary lung cancers and 8 nonspecific chronic inflammations. Results of pathological examination of 4 pGGOs revealed 1 primary lung cancers, 1 atypical adenomatous

  14. A new computationally efficient CAD system for pulmonary nodule detection in CT imagery.

    Science.gov (United States)

    Messay, Temesguen; Hardie, Russell C; Rogers, Steven K

    2010-06-01

    Early detection of lung nodules is extremely important for the diagnosis and clinical management of lung cancer. In this paper, a novel computer aided detection (CAD) system for the detection of pulmonary nodules in thoracic computed tomography (CT) imagery is presented. The paper describes the architecture of the CAD system and assesses its performance on a publicly available database to serve as a benchmark for future research efforts. Training and tuning of all modules in our CAD system is done using a separate and independent dataset provided courtesy of the University of Texas Medical Branch (UTMB). The publicly available testing dataset is that created by the Lung Image Database Consortium (LIDC). The LIDC data used here is comprised of 84 CT scans containing 143 nodules ranging from 3 to 30mm in effective size that are manually segmented at least by one of the four radiologists. The CAD system uses a fully automated lung segmentation algorithm to define the boundaries of the lung regions. It combines intensity thresholding with morphological processing to detect and segment nodule candidates simultaneously. A set of 245 features is computed for each segmented nodule candidate. A sequential forward selection process is used to determine the optimum subset of features for two distinct classifiers, a Fisher Linear Discriminant (FLD) classifier and a quadratic classifier. A performance comparison between the two classifiers is presented, and based on this, the FLD classifier is selected for the CAD system. With an average of 517.5 nodule candidates per case/scan (517.5+/-72.9), the proposed front-end detector/segmentor is able to detect 92.8% of all the nodules in the LIDC/testing dataset (based on merged ground truth). The mean overlap between the nodule regions delineated by three or more radiologists and the ones segmented by the proposed segmentation algorithm is approximately 63%. Overall, with a specificity of 3 false positives (FPs) per case/patient on

  15. Red nodule on the breast

    Directory of Open Access Journals (Sweden)

    Roberta Colucci

    2012-01-01

    Full Text Available A 63-year-old woman living in the countryside referred to our department with a 2-month history of a red nodule localized on the right breast. Histological examination, immunohistochemical analyses and serologic evaluation conducted with ELISA and Western blot were performed. Clinical diagnosis of borrelial lymphocytoma was not possible solely on the clinical presentation of a classical nodular form without lymphoadenopathy. An absence of a referred prior tick bite and a previous or concomitant erythema migrans at clinical presentation rendered a more challenging diagnosis. The fact that the patient lived in the countryside, the appearance of the breast nodule in September, and serologic, histologic, and immunohistochemical analysis facilitated the diagnosis of borrelial lymphocytoma. We report this case to highlight the importance of an investigation of Lyme borreliosis when a patient living in the countryside presents with a red nodule of the nipple and areola.

  16. 图像纹理特征在肺结节18F-FDG PET/CT显像诊断中的应用%Parametric features of image textures in 18F-FDG PET/CT evaluation of lung nodules

    Institute of Scientific and Technical Information of China (English)

    王长梅; 管一晖; 张文强; 左传涛; 华逢春

    2013-01-01

    textures on 18F-FDG PET/CT for the differentiation between malignant and benign pulmonary nodules and compare the diagnostic performance of these parameters with SUVmax.Methods 18F-FDG PET/CT images of 170 patients (102 males,68 females,age range:29-81 (mean 59)years) with pulmonary nodules were retrospectively evaluated.Eightynine 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 SUVmax 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 SUVmax 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 SUVmax for the differential diagnosis were compared with x2 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% CI0.732-0.819; 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 SUVmax-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 a cut-off value of 2.5.The sensitivity of the textural

  17. Validation of full cavitation model in cryogenic fluids

    Institute of Scientific and Technical Information of China (English)

    CAO XiaoLi; ZHANG XiaoBin; QIU LiMin; GAN ZhiHua

    2009-01-01

    Numerical simulation of cavitation in cryogenic fluids is important in improving the stable operation of he propulsion system in liquid-fuel rocket. It also represents a broader class of problems where the fluid is operating close to its critical point and the thermal effects of cavitation are pronounced. The present article focuses on simulating cryogenic cavitation by implementing the "full cavitation model", coupled with energy equation, in conjunction with iteraUve update of the real fluid properties at local temperatures. Steady state computations are then conducted on hydrofoil and ogive in liquid nitrogen and hydrogen respectively, based on which we explore the mechanism of cavitation with thermal ef-fects. Comprehensive comparisons between the simulation results and experimental data as well as previous computations by other researchers validate the full cavitation model in cryogenic fluids. The sensitivity of cavity length to cavitation number is also examined.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Growing PET positive nodule in a patient with histoplasmosis: case report

    Directory of Open Access Journals (Sweden)

    Baram Daniel

    2006-09-01

    Full Text Available Abstract Background Pulmonary histoplasmosis is a mycotic infection that often resembles pulmonary malignancy and continues to complicate the evaluation of pulmonary nodules. Case presentation We report a case of an immunocompetent patient who, despite adequate treatment for known histoplasmosis lung infection, presented with radiological and F-18 fluorodeoxyglucose (FDG positron emission tomography (PET findings mimicking primary lung malignancy which eventually required surgical resection. Conclusion Histoplasmosis infection may radiologically resemble pulmonary malignancy, often causing a diagnostic dilemma. PET imaging is currently used for and considered accurate in the evaluation of pulmonary nodules. However, overlap in PET standardized uptake value (SUV between granulomatous and malignant lesions decreases the accuracy of PET as a diagnostic modality. Future advances in PET imaging are needed to improve its accuracy in the evaluation of pulmonary nodules in areas where histoplasmosis is endemic.

  4. Application of preoperative CT-guided Hook-wire localization of pulmonary nodules in thoracoscopic lobectomy of lung%CT引导下带钩钢丝定位行肺部磨玻璃影结节全腔镜下肺切除术28例分析

    Institute of Scientific and Technical Information of China (English)

    束余声; 赵伟刚; 石维平; 陆世春

    2015-01-01

    Objective To evaluate the application of preoperative CT-guided Hook-wire localization of pulmonary nodules in thoracoscopic lobectomy of lung.Method Twenty eight patients with 31 pulmonary nodules of ground-glass opacity (GGO) detected by CT scan were admitted in our hospital from December 2008 to December 2013,including 17 males and 11 females with an average age of 55.The lesions were located by CT-guided Hook-wire technique,and lobectomy plus lymphadenectomy or pulmonary wedge resection were performed according to the results of fast frozen pathology.The characteristics of pulmonary nodules and general condition of the patients were analyzed.Results Among 31 nodules,19 were malignant and 12 benign with an average size of (1.8 ± 0.6) cm and thickness of (1.2-± 0.4) cm.The vertical distance from pleural to nodules was (1.5 ± 0.7) cm and the insert depth of needle was (2.5 ± 0.9) cm.The time for CT-guided Hook-wire localization was (16.5 ± 5.2) min.The operation time for pulmonary wedge resection and pulmonary lobectomy was (18.5 ± 5.5) min and (54.7 ± 12.5) min,respectively.Intraoperative frozen section showed malignant tumors in 18 patients (19 GGO nodules),lobectomy plus lymphadenectomy were performed in 16 cases; 2 patients did not undergo pulmonary lobectomy because of poor physical condition or 2 GGO nodules in different lobes.There were no operation complications in this series.Postoperative pathologic findings of 31 nodules showed 9 cases of adenocarcinoma,10 bronchioloalveolar carcinoma,5 atypical adenomatous hyperplasia,2 epithelioid hemangioendothelioma,2 chronic inflammation,1 hamartoma,1 inflammatory pseudotumor and 1 sarcoidosis.The average postoperative hospital stay was (6.6 ± 1.9) days.Conclusions Endoscopic resection of pulmonary GGO nodules with CT-guided Hook-wire localization technique is feasible and safe,with less complications and less time consuming.%目的 探讨术前CT引导下Hook-wire定位在全腔镜下肺部磨玻璃影(GGO

  5. Cytological findings in scintigraphically nonfunctioning thyroid nodules

    Directory of Open Access Journals (Sweden)

    Radović Branislava

    2010-01-01

    Full Text Available Background/Aim. The major one among the procedures for evaluating changes in the thyroid nodules is fine needle aspiration biopsy (FNAB. Thyroid scintigraphy is commonly used in diagnostic algoritham of nodules. Less than 5% of examined nodules show to be malignant. Scintigraphically, nodules could be classified as functional and nonfunctional. It is estimated that the risk of malignacy in nonfunctional nodules ranges from 8% to 25% and more. Aspiration punction provides 100% specific and positive predictive value. The aim of the study was to establish the distribution of cytological findings in nonfunctioning thyroid nodules. Methods. The prospective study enrolled 112 patients, 104 women and 8 men, submitted to thyroid scintigraphy for known thyroid nodule disorder. Scintigraphy was performed about half an hour after iv administration of 74 MBq of sodium-pertehnetate. A pin hole collimator was used. Scintigrams were visually evaluated, and absence of radiopharmaceutic in a nodule was estimated as nonfunctional one. Such nodules were afterwards subjected to FNAB and material obtained was cytologically analyzed. Results. In our patients nonfunctioning nodules comprised tissue of colloid struma, thyroid cyst, regular thyroid tissue, follicular lesion, oxiphillic lesion, papillary carcinoma tissue and tissue of lymphocytic thyroiditis. The most frequent cytological finding were colloid cysts (52%. A total of 70% were female nodules. Five citological findings were histopathologically analyzed. Conclusion. Cytological finding of nonfunctional nodules determines of the decision on radical therapy, and our preliminary results imply the need of FNAB routine use in nuclear medicine practice.

  6. Cavitation inception following shock wave passage

    NARCIS (Netherlands)

    Ohl, C.D.

    2002-01-01

    Cavitation bubble nucleation following the passage of an extracorporeal shock wave lithotripter pulse is investigated experimentally and numerically. In the experiments two configurations are considered: Free passage of the shock wave, and reflection of the shock wave from a rigid reflector. The nuc

  7. Classification of lubricants according to cavitation criteria

    NARCIS (Netherlands)

    Meged, Y.; Venner, C.H.; Napel, ten W.E

    1995-01-01

    Cavitation in lubrication liquids has long been known to be detrimental to components in hydraulic systems. Damage has been detected in journal bearings, especially under severe dynamic loading, gears, squeeze film dampers and valves. These findings have led to intensive studies of metal resistance

  8. 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.

  9. On cavitation instabilities with interacting voids

    DEFF Research Database (Denmark)

    Tvergaard, Viggo

    2012-01-01

    voids so far apart that the radius of the plastic zone around each void is less than 1% of the current spacing between the voids, can still affect each others at the occurrence of a cavitation instability such that one void stops growing while the other grows in an unstable manner. On the other hand...

  10. Cavitation inception following shock wave passage

    NARCIS (Netherlands)

    Ohl, C.D.

    2002-01-01

    Cavitation bubble nucleation following the passage of an extracorporeal shock wave lithotripter pulse is investigated experimentally and numerically. In the experiments two configurations are considered: Free passage of the shock wave, and reflection of the shock wave from a rigid reflector. The nuc

  11. Cavitation of a Physically Associating Gel

    Science.gov (United States)

    Mishra, Satish; Kundu, Santanu

    Self-assembly of block copolymers in selective solvents form ordered structures such as micelles, vesicles, and physically crosslinked gels due to difference in their interaction with solvents. These gels have wide range of applications in tissue engineering, food science and biomedical field due to their tunable properties and responsiveness with changing environmental conditions. Pressurization of a defect inside a physically associating gel can lead to elastic instability (cavitation) leading to failure of the gel. The failure behavior involves dissociation of physical networks. A thermoreversible, physically associating gel with different volume fractions of a triblock copolymer, poly (methyl methacrylate)-poly (n-butyl acrylate)-poly (methyl methacrylate) [PMMA-PnBA-PMMA] in 2-ethyl 1-hexanol, a midblock selective solvent, is considered here. Mechanical properties were investigated using shear rheology and cavitation experiments. The experimental data is fitted with a constitutive model that captures the stiffening behavior followed by softening behavior of a physical gel. Finite element analysis has been performed on cavitation rheology geometry to capture the failure behavior and to calculate energy release rate during cavitation experiments.

  12. Modeling of Cavitating Flow through Waterjet Propulsors

    Science.gov (United States)

    2015-02-18

    break down due to massive suction side flow separation (stall). In Figure 3, photographs from tunnel testing and computed results are shown. The...128, pp. 1308-1323. Mishra C. & Peles, Y. (2005) "Cavitation in flow through a micro- orifice inside a silicon micro- channel,’ Phvs. Fluids 17

  13. Measuring cavitation and its cleaning effect

    NARCIS (Netherlands)

    Verhaagen, Bram; Fernandez Rivas, David

    2016-01-01

    The advantages and limitations of techniques for measuring the presence and amount of cavitation, and for quantifying the removal of contaminants, are provided. After reviewing chemical, physical, and biological studies, a universal cause for the cleaning effects of bubbles cannot yet be concluded.

  14. Ultrasound induced by CW laser cavitation bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Korneev, N; Montero, P Rodriguez; Ramos-Garcia, R; Ramirez-San-Juan, J C; Padilla-Martinez, J P, E-mail: korneev@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica, Apt. Postal 51 y 216 CP72000, Puebla, Pue. (Mexico)

    2011-01-01

    The generation of ultrasound by a collapsing single cavitation bubble in a strongly absorbing liquid illuminated with a moderate power CW laser is described. The ultrasound shock wave is detected with hydrophone and interferometric device. To obtain a stronger pulse it is necessary to adjust a liquid absorption and a beam diameter. Their influence can be qualitatively understood with a simple model.

  15. Modelling cavitating flow around underwater missiles

    Directory of Open Access Journals (Sweden)

    Fabien Petitpas

    2011-12-01

    Full Text Available The diffuse interface model of Saurel et al. (2008 is used for the computation of compressible cavitating flows around underwater missiles. Such systems use gas injection and natural cavitation to reduce drag effects. Consequently material interfaces appear separating liquid and gas. These interfaces may have a really complex dynamics such that only a few formulations are able to predict their evolution. Contrarily to front tracking or interface reconstruction method the interfaces are computed as diffused numerical zones, that are captured in a routinely manner, as is done usually with gas dynamics solvers for shocks and contact discontinuity. With the present approach, a single set of partial differential equations is solved everywhere, with a single numerical scheme. This leads to very efficient solvers. The algorithm derived in Saurel et al. (2009 is used to compute cavitation pockets around solid bodies. It is first validated against experiments done in cavitation tunnel at CNU. Then it is used to compute flows around high speed underwater systems (Shkval-like missile. Performance data are then computed showing method ability to predict forces acting on the system.

  16. Control of Propeller Cavitation in Operational Conditions

    NARCIS (Netherlands)

    Vrijdag, A.

    2009-01-01

    Off design conditions can have a severe impact on ship propulsion system behaviour. Resistance increase for instance leads to a higher engine loading, and can also easily lead to a decrease of cavitation inception speed with respect to calm water conditions. Wakefield variations due to ship motions,

  17. Cavitation for improved sludge conversion into biogas

    NARCIS (Netherlands)

    Stoop, A.H.; Bakker, T.W.; Kramer, H.J.M.

    2015-01-01

    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 anaer

  18. Achromobacter xylosoxidans Infection Presenting as a Pulmonary Nodule Mimicking Cancer ▿

    OpenAIRE

    2011-01-01

    Achromobacter xylosoxidans is typically isolated from pulmonary sources, presenting as pneumonia in immunosuppressed individuals. We describe a novel clinical presentation of A. xylosoxidans infection presenting as multiple spiculated, pulmonary nodules mimicking cancer for which the patient underwent a wedge resection of the lung for diagnosis and staging of presumptive cancer.

  19. 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.

    2015-01-01

    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 b

  20. Computerized comprehensive data analysis of Lung Imaging Database Consortium (LIDC)

    OpenAIRE

    Tan, Jun; Pu, Jiantao; Zheng, Bin; Wang, Xingwei; Leader, Joseph K.

    2010-01-01

    Purpose: Lung Image Database Consortium (LIDC) is the largest public CT image database of lung nodules. In this study, the authors present a comprehensive and the most updated analysis of this dynamically growing database under the help of a computerized tool, aiming to assist researchers to optimally use this database for lung cancer related investigations.

  1. Artificial penile nodules: case reports.

    OpenAIRE

    Lim, K B; Seow, C.S.; Tulip, T; Daniel, M.; Vijayasingham, S M

    1986-01-01

    An interesting cultural practice of implanting foreign bodies under the skin of the penis for enhancing sexual excitement in the man's sexual partner is described. Recognition of this is important to venereologists because of their primary concern with the genital area. The term artificial penile nodule has been suggested for the condition resulting from this practice.

  2. 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)

  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. Phylogenetic perspectives on the origins of nodulation.

    Science.gov (United States)

    Doyle, Jeff J

    2011-11-01

    Recent refinements to the phylogeny of rosid angiosperms support the conclusion that nodulation has evolved several times in the so-called N(2)-fixing clade (NFC), and provide dates for these origins. The hypothesized predisposition that enabled the evolution of nodulation occurred approximately 100 million years ago (MYA), was retained in the various lineages that radiated rapidly shortly thereafter, and was functional in its non-nodulation role for at least an additional 30 million years in each nodulating lineage. Legumes radiated rapidly shortly after their origin approximately 60 MYA, and nodulation most likely evolved several times during this radiation. The major lineages of papilionoid legumes diverged close to the time of origin of nodulation, accounting for the diversity of nodule biology in the group. Nodulation symbioses exemplify the concept of "deep homology," sharing various homologous components across nonhomologous origins of nodulation, largely due to recruitment from existing functions, notably the older arbuscular mycorrhizal symbiosis. Although polyploidy may have played a role in the origin of papilionoid legume nodules, it did not do so in other legumes, nor did the prerosid whole-genome triplication lead directly to the predisposition of nodulation.

  5. 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.

  6. 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.

  7. 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 of their ......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...

  8. 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.)

  9. A solitary pulmonary ground-glass nodule in adult systemic langerhans’ cell histiocytosis

    Science.gov (United States)

    Zhou, Ying; Li, Yunyuan; Fan, Li; Liu, Shiyuan

    2015-01-01

    During a thoracic computed tomography (CT) scan, a 36-year-old male was diagnosed with a solitary oval pulmonary mixed ground-glass nodule in the right upper lobe of the lung. The edge of the nodule was well-defined, and its largest axial size was approximately 1.1×0.9 cm2. This nodule was slightly lobulated, but not obviously speculated. Solid components, micro-cystic lucency shadow, small high-density rings and tiny vascular branches were all visible in the nodule. During hospitalization, a technetium 99 m methylene diphosphonate (Tc-99 m MDP) bone scan was performed, which showed a skeletal foci with abnormal uptake in the left iliac. A pulmonary lobectomy of the right upper lobe of the lung by video-assisted thoracoscopy was performed. In post-operative pathological photomicrographs, proliferative Langerhans’ cells, eosinophils and lymphocytes were found. Immunohistochemistry showed that the expression of S-100 protein, CD1a, and CD68 antigen all stained positive. Since Langerhans’ cell histiocytosis (LCH) that is also associated with isolated mixed ground-glass nodules is relatively rare, such a multi-systemic LCH case as identified herein, is reported. PMID:26722574

  10. 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

    2015-02-07

    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

  11. STUDY UPON THE CAVITATION PHENOMENON OF THE ROTORS

    Directory of Open Access Journals (Sweden)

    Beazit ALI

    2011-11-01

    Full Text Available The main problem of the hydrodynamics of cavitation implosion of a single bubble, consists inpressure and velocity fields determination, including the collapse velocity of the bubble wall. By analysis thetheoretic and experimental phenomenon it establish the implicit function which describes this phenomenon. Byapplication the  theorem for this implicit function it finds the criterion equation of phenomenon.Depending on operating condition various cavitation patterns can be observed on a body surface astravelling bubbles, attached sheet cavitation, shear cavitation or vortex cavitation. Leading edge attachedpartialcavitation is commonly encountered on rotor blades or on hydrofoil. It corresponds to the case for whichavapor cavity is attached in the vecinity of the leading edge and extends over a fraction of the foil surface. Itgenerally takes places at incidence angles for which a leading edge pressure peak occurs and reduced belowtheliquid vapor pressure. At the early phases of development, leading edge partial cavitation is steady.

  12. Computational Analyses of Cavitating Flows in Cryogenic Liquid Hydrogen

    Institute of Scientific and Technical Information of China (English)

    Tiezhi Sun; Yingjie Wei; Cong Wang∗

    2016-01-01

    The objective of this study is to analyze the fundamental characteristics and the thermodynamic effects of cavitating flows in liquid hydrogen. For this purpose, numerical simulation of cavitating flows are conducted over a three dimensional hydrofoil in liquid hydrogen. Firstly, the efficiency of this computational methodology is validated through comparing the simulation results with the experimental measurements of pressure and temperature. Secondly, after analysing the cavitating flows in liquid hydrogen and water, the characteristics under cryogenic conditions are highlighted. The results show that the thermodynamic effects play a significant role in the cavity structure and the mass transfer, the dimensionless mass transfer rate of liquid hydrogen is much larger, and the peak value is about ninety times as high as water at room temperature. Furthermore, a parametric study of cavitating flows on hydrofoil is conducted by considering different cavitation number and dimensionless thermodynamic coefficient. The obtained results provide an insight into the thermodynamic effect on the cavitating flows.

  13. U-shaped Vortex Structures in Large Scale Cloud Cavitation

    Science.gov (United States)

    Cao, Yantao; Peng, Xiaoxing; Xu, Lianghao; Hong, Fangwen

    2015-12-01

    The control of cloud cavitation, especially large scale cloud cavitation(LSCC), is always a hot issue in the field of cavitation research. However, there has been little knowledge on the evolution of cloud cavitation since it is associated with turbulence and vortex flow. In this article, the structure of cloud cavitation shed by sheet cavitation around different hydrofoils and a wedge were observed in detail with high speed camera (HSC). It was found that the U-shaped vortex structures always existed in the development process of LSCC. The results indicated that LSCC evolution was related to this kind of vortex structures, and it may be a universal character for LSCC. Then vortex strength of U-shaped vortex structures in a cycle was analyzed with numerical results.

  14. Comminution of Mica by Cavitation Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    GUO Chu-wen; LIU Lin-sheng; HAN Dong-tai; LI Ai-min; ZHANG Dong-hai

    2003-01-01

    The comminution of mica with an abrasive water jet is mainly based on three knids of effects, that is, high-speed collision, cavitating effect and shearing effect. Cavitation abrasive water jet was applied for the comminution of mica because cavitation abrasive water jet can make full use of the three effects mentioned above. Besides high speed impacting among particles,cavitation and shearing were also enhanced due to the divergent angle at the outlet of the cavitation nozzle.A JME-200CX transmission electron microscope was used for observing the size distribution of particles.Variance analysis on the experimental results indicates that the effect of cavitation is much more significant than that of collision.The effect of pressure on comminution results becomes less with the decrease of the particle size.

  15. Cavitation erosion behavior of nickel-aluminum bronze weldment

    Institute of Scientific and Technical Information of China (English)

    李小亚; 闫永贵; 许振明; 李建国

    2003-01-01

    Cavitation erosion behavior of nickel-aluminum bronze(NAB)weldment in 3.5% NaCl aqueous solution was studied by magnetostrictive vibratory device for cavitation erosion.The results show that cavitation erosion resistance of the weld zone(WZ)of the weldment is superior to that of the base metal.SEM observation of eroded specimens reveals that the phases undergoing selective attack by the stress of cavitation erosion at the early stage of cavitation erosion are:martensite in the WZ,α phase in the heat-affected zone(HAZ)and eutectoidal phase in the base metal; the microcracks causing cavitation damage initiate at the phase boundaries.

  16. Cavitation measurement during sonic and ultrasonic activated irrigation.

    Science.gov (United States)

    Macedo, Ricardo; Verhaagen, Bram; Rivas, David Fernandez; Versluis, Michel; Wesselink, Paul; van der Sluis, Luc

    2014-04-01

    The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. The amount of cavitation generated around several endodontic instruments was measured by sonochemiluminescence dosimetry inside 4 root canal models of human dimensions and varying complexity. Furthermore, the spatial distribution of the sonochemiluminescence in the root canal was visualized with long-exposure photography. Instrument oscillation frequency, ultrasonic power, and file taper influenced the occurrence and amount of cavitation. In UAI, cavitation was distributed between the file and the wall extending beyond the file and inside lateral canals/isthmuses. In sonic activated irrigation, no cavitation was detected. Cavitation was shown to occur in UAI at clinically relevant ultrasonic power settings in both straight and curved canals but not around sonically oscillating instruments, driven at their highest frequency. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Simulations of Steady Cavitating Flow in a Small Francis Turbine

    Directory of Open Access Journals (Sweden)

    Ahmed Laouari

    2016-01-01

    Full Text Available The turbulent flow through a small horizontal Francis turbine is solved by means of Ansys-CFX at different operating points, with the determination of the hydrodynamic performance and the best efficiency point. The flow structures at different regimes reveal a large flow eddy in the runner and a swirl in the draft tube. The use of the mixture model for the cavity/liquid two-phase flow allowed studying the influence of cavitation on the hydrodynamic performance and revealed cavitation pockets near the trailing edge of the runner and a cavitation vortex rope in the draft tube. By maintaining a constant dimensionless head and a distributor vane opening while gradually increasing the cavitation number, the output power and efficiency reached a critical point and then had begun to stabilize. The cavitation number corresponding to the safety margin of cavitation is also predicted for this hydraulic turbine.

  18. Detached eddy simulation of unsteady cavitation and pressure fluctuation around 3-D NACA66 hydrofoil

    Directory of Open Access Journals (Sweden)

    Zhang De-Sheng

    2015-01-01

    Full Text Available The unsteady cavitating flow and pressure fluctuation around the 3-D NACA66 hydrofoil were simulated and validated based on detached eddy simulation turbulence model and a homogeneous cavitation model. Numerical results show that detached eddy simulation can predict the evolution of cavity inception, sheet cavitation growth, cloud cavitation shedding, and breakup, as well as the pressure fluctuation on the surface of hydrofoil. The sheet cavitation growth, detachment, cloud cavitation shedding are responsible for the features of the pressure fluctuation.

  19. Time-evolving statistics of cavitation damage on metallic surfaces.

    Science.gov (United States)

    Diodati, P; Marchesoni, F

    2002-11-01

    The statistics of surface damage on polycrystalline aluminium plates caused by acoustic cavitation is studied experimentally as a function of time. Cavitation is shown to produce a uniform distribution of crater-like holes with different depth, area and eccentricity. Most notably, the size distribution of such craters evolves with time from a gamma function into a power law. By contrast, on the surface of a martensitic Cu-Ni-Al crystal cavitation damage generates ramified patterns, reminiscent of a fractal object.

  20. L-Area Cavitation Tests Final Analysis - Limits Application

    Energy Technology Data Exchange (ETDEWEB)

    Wood, D.C.

    2001-06-26

    The L-Area cavitation test was designed to better define the onset of cavitation in the reactor system. The onset of gas evolution in the effluent piping and pump cavitation was measured using state-of-the-art equipment to provide data with a high confidence and low uncertainty level. The limits calculated from the new data will allow an approximate two percent increase in reactor power if the reactor is effluent temperature-limited with no compromise in reactor safety.

  1. Preparation of graphene by jet cavitation

    Science.gov (United States)

    Shen, Zhigang; Li, Jinzhi; Yi, Min; Zhang, Xiaojing; Ma, Shulin

    2011-09-01

    Despite its bright prospects, graphene faces challenges including issues concerning mass production. Here we present a totally green approach whereby common crystal graphite can be exfoliated into graphene sheets in aqueous solution by jet cavitation. This is possible mainly because the tensile stress caused by graphite-solution interfacial reflection of compressive waves acts an intensive 'suction disk' on the graphite flakes. We confirm the presence of graphene sheets by diverse characterizations. The graphene yield by our method is estimated as ~ 4 wt%, which could potentially be improved by further processing. The method, of a mechanical nature, is powerful compared to the traditional low-throughput micromechanical cleavage. Our work here illustrates jet cavitation as a facile, low cost, timesaving and laborsaving route, which can potentially be scaled up to mass production of graphene.

  2. Cavitation-based hydro-fracturing simulator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John; Wang, Hong; Ren, Fei; Cox, Thomas S.

    2016-11-22

    An apparatus 300 for simulating a pulsed pressure induced cavitation technique (PPCT) from a pressurized working fluid (F) provides laboratory research and development for enhanced geothermal systems (EGS), oil, and gas wells. A pump 304 is configured to deliver a pressurized working fluid (F) to a control valve 306, which produces a pulsed pressure wave in a test chamber 308. The pulsed pressure wave parameters are defined by the pump 304 pressure and control valve 306 cycle rate. When a working fluid (F) and a rock specimen 312 are included in the apparatus, the pulsed pressure wave causes cavitation to occur at the surface of the specimen 312, thus initiating an extensive network of fracturing surfaces and micro fissures, which are examined by researchers.

  3. Cavitated Bifurcation for Incompressible Hyperelastic Material

    Institute of Scientific and Technical Information of China (English)

    任九生; 程昌钧

    2002-01-01

    The spherical cavitated bifurcation for a hyperelastic solid sphere made of the incompressible Valanis-Landel material under boundary dead-loading is examined. The analytic solution for the bifurcation problem is obtained. The catastrophe and concentration of stresses are discussed. The stability of solutions is discussed through the energy comparison.And the growth of a pre-existing micro-void is also observed.

  4. Impact of acoustic cavitation on food emulsions.

    Science.gov (United States)

    Krasulya, Olga; Bogush, Vladimir; Trishina, Victoria; Potoroko, Irina; Khmelev, Sergey; Sivashanmugam, Palani; Anandan, Sambandam

    2016-05-01

    The work explores the experimental and theoretical aspects of emulsification capability of ultrasound to deliver stable emulsions of sunflower oil in water and meat sausages. In order to determine optimal parameters for direct ultrasonic emulsification of food emulsions, a model was developed based on the stability of emulsion droplets in acoustic cavitation field. The study is further extended to investigate the ultrasound induced changes to the inherent properties of raw materials under the experimental conditions of sono-emulsification.

  5. Single bubble sonoluminescence and stable cavitation

    Institute of Scientific and Technical Information of China (English)

    CHEN Qian; QIAN Menglu

    2004-01-01

    A single bubble trapped at an antinode of an acoustic standing wave field in water can emit 50ps-140ps light pulses, called "single bubble sonoluminescence" (SBSL). It arouses much interest in physical acoustics because of its highly non-linear characteristics, high concentration of energy, and stable cavitation behavior. In this paper, bubble stability, the dynamic behavior of bubbles, non-invasive measurement of driving acoustic pressure and Mie scattering method are introduced.

  6. Photoacoustic cavitation for theranostics: mechanism, current progress and applications

    Science.gov (United States)

    Feng, Y.; Qin, D.; Wan, M.

    2015-12-01

    As an emerging cavitation technology, photoacoustic cavitation (PAC) means the formation of bubbles in liquids using focused laser and pre-established ultrasound synchronously. Its significant advantages include the decreased threshold of each modality and the precise location of cavitation determined by the focused laser. In this paper, a brief review of PAC is presented, including the physical mechanism description, the classic experimental technology, the representative results in variety of media, and its applications in biomedical imaging and therapy. Moreover, some preliminary results of PAC in perfluoropentane (PFP) liquid and PFP droplets investigated by passive cavitation detection (PCD) in our group are also presented.

  7. Understanding Cavitation Intensity through Pitting and Pressure Pulse Analysis

    Science.gov (United States)

    Jayaprakash, A.; Singh, S.; Choi, J.-K.; Chahine, G.

    2011-11-01

    Cavitation erosion is of interest to the designers of ship propulsion devices because of its detrimental effects. One of the difficulties of predicting cavitation erosion is that the intensity of cavitation is not well predicted or defined. In this work we attempt to define the intensity of a cavitation erosion field through analysis of cavitation induced erosion pits and pressure pulses. In the pitting tests, material samples were subjected to cavitation field for a short duration of time selected within the test sample's incubation period, so that the test sample undergoes plastic deformation only. The sample material reacts to these cavitation events by undergoing localized permanent deformation, called pits. The resulting pitted sample surfaces were then optically scanned and analyzed. The pressure signals under cavitating jets and ultrasonic horns, for different conditions, were experimentally recorded using high frequency response pressure transducers. From the analysis of the pitting data and recorded pressure signals, we propose a model that describes the statistics, which in the future can be used to define the cavitation field intensity. Support for this work was provided by Office of Naval Research (ONR) under contract number N00014-08-C-0450, monitored by Dr. Ki-Han Kim.

  8. Modeling Unsteady Cavitation Effects and Dynamic Loads in Cryogenic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There currently are no analytical or CFD tools that can reliably predict unsteady cavitation dynamics in liquid rocket turbopumps. Cavitation effects, particularly...

  9. AN EXPERIMENTAL AND NUMERICAL PREDICTION OF MARINE PROPELLER NOISE UNDER CAVITATING AND NON-CAVITATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Bagheri

    2015-06-01

    Full Text Available In this study, the hydrodynamics and noise prediction of a five blade marine propeller were analyzed through numerical and experimental methods under variety operational conditions. The hydrodynamics of the propeller was studied and the characteristic curves were presented in both numerical and experimental methods. Inception and development of sheet cavitation conditions are obtained in both numerical and experimental methods. The cavitation was started and developed by either increasing the propeller rotational speed in constant pressure or decreasing pressure, while the velocity was kept constant. Good agreements are observed between numerical and experimental results, qualitatively and quantitatively. The noise of the propeller was analyzed through Computational fluid dynamics (CFD method, based on the formulation of Ffowcs Williams and Hawkings (FW-H. Similarly, the experimental results collected from hydrophones were compared with numerical simulations. Finally, the effects of reflection in cavitation tunnel were obtained by considering overall sound pressure levels in numerical and experimental results.

  10. 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.

  11. Pseudotumor pulmonar como apresentação inicial de granulomatose de Wegener Lung pseudotumor as the initial presentation of Wegener's granulomatosis

    Directory of Open Access Journals (Sweden)

    Marcelo Fouad Rabahi

    2009-04-01

    Full Text Available A granulomatose de Wegener é uma doença inflamatória multissistêmica de etiologia desconhecida, que se caracteriza por vasculite de pequeno e médio calibre. As manifestações clínicas mais comuns envolvem o trato respiratório superior, pulmões e rins e as alterações encontradas nos exames de imagem são geralmente opacidades pulmonares ou nódulos múltiplos, bilaterais e, em 50% dos casos, cavitações. O tratamento é feito com corticoides e imunossupressores. Descreve-se um caso atípico de um homem de 61 anos cuja investigação inicial de um tumor pulmonar unilateral evidenciou, na verdade, Granulomatose de Wegener.Wegener's granulomatosis is a multisystemic inflammatory illness of unknown etiology, characterized by vasculitis of small and medium caliber vessels. The most common clinical manifestations involve the upper respiratory tract, lungs and kidneys. Common alterations in imaging studies include pulmonary opacities and bilateral multiple nodules, cavitations occurring in 50% of the cases. Treatment includes corticosteroids and immunosuppressants. We describe an atypical case of a 61-year-old man initially investigated due to suspicion of a unilateral lung tumor, which proved to be, in fact, a case of Wegener's granulomatosis.

  12. Visualization of cavitation in flanged poppet valve; Tsubatsuki popetto bennai no cavitation no kashika

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, A.; Tsukiji, T. [Ashikaga Institute of Technology, Tochigi (Japan); Sumita, T. [Tokimec Inc., Tokyo (Japan)

    1999-01-15

    Only half-cut models are dealt with in reports made available so far about experiments on the visualization of cavitation in what is called a flanged poppet valve, which is a valve whose cone-shaped poppet is provided with flanges at its end and periphery for reduction in fluid force. In the present report, a valve is drilled from three directions in an experiment for visualizing flows near the poppet valve flanges, which is for three-dimensional model visualization. The shapes of the poppet valve flanges are changed in various ways for the study of cavitation generation limits. (translated by NEDO)

  13. Software performance in segmenting ground-glass and solid components of subsolid nodules in pulmonary adenocarcinomas.

    Science.gov (United States)

    Cohen, Julien G; Goo, Jin Mo; Yoo, Roh-Eul; Park, Chang Min; Lee, Chang Hyun; van Ginneken, Bram; Chung, Doo Hyun; Kim, Young Tae

    2016-12-01

    To evaluate the performance of software in segmenting ground-glass and solid components of subsolid nodules in pulmonary adenocarcinomas. Seventy-three pulmonary adenocarcinomas manifesting as subsolid nodules were included. Two radiologists measured the maximal axial diameter of the ground-glass components on lung windows and that of the solid components on lung and mediastinal windows. Nodules were segmented using software by applying five (-850 HU to -650 HU) and nine (-130 HU to -500 HU) attenuation thresholds. We compared the manual and software measurements of ground-glass and solid components with pathology measurements of tumour and invasive components. Segmentation of ground-glass components at a threshold of -750 HU yielded mean differences of +0.06 mm (p = 0.83, 95 % limits of agreement, 4.51 to 4.67) and -2.32 mm (p software (at -350 HU) and pathology measurements and between the manual (lung and mediastinal windows) and pathology measurements were -0.12 mm (p = 0.74, -5.73 to 5.55]), 0.15 mm (p = 0.73, -6.92 to 7.22), and -1.14 mm (p Software segmentation of ground-glass and solid components in subsolid nodules showed no significant difference with pathology. • Software can effectively segment ground-glass and solid components in subsolid nodules. • Software measurements show no significant difference with pathology measurements. • Manual measurements are more accurate on lung windows than on mediastinal windows.

  14. Thyroid follicular carcinoma presenting as metastatic skin nodules

    Directory of Open Access Journals (Sweden)

    Asad Jehangir

    2015-02-01

    Full Text Available Background: Follicular thyroid cancer (FTC metastasizes most commonly to the lungs and non-cranial bones. Skull and skin are uncommon sites and usually manifest well after the diagnosis of primary malignancy. Metastasis to skull and skin as the presenting feature of FTC is infrequently reported in the literature. Case presentation: A 65-year-old Caucasian woman with a history of thyroid nodule presented with the complaint of rapidly growing skull nodules which had been present for 3 years but were stable previously. She denied any fevers, chills, history of trauma, or weight loss. She denied any history of smoking or head and neck irradiation. On physical examination, she had two non-tender gray cystic lesions – one on her left temporal region and the other on the right parietal region. Biopsy was consistent with metastatic FTC. Magnetic resonance imaging of the brain demonstrated 7.1×3.8 cm and 3.7×4.5 cm fairly homogeneous, enhancing, relatively well-defined masses centered in the posterior and left anterior lateral calvarium with intracranial and extracranial extensions but without any vasogenic edema or mass effect on the brain. Thyroid ultrasound showed numerous nodules in both lobes. The patient underwent a total thyroidectomy. Histopathological studies of the thyroid gland revealed a well-differentiated FTC in the left lobe. Then she underwent resection of the tumor in multiple stages. She did not have any recurrence of the FTC or metastases during the follow-up period and will be receiving radioactive iodine treatment. Conclusion: Bone and lung are the common sites of metastasis from FTC, but involvement of skull or skin is unusual, particularly as the presenting feature. Metastases from FTC should be in the differential of patients with new osteolytic hypervascular skull lesions or cutaneous lesions in head and neck area.

  15. Mechanistic action of gibberellins in legume nodulation.

    Science.gov (United States)

    Hayashi, Satomi; Gresshoff, Peter M; Ferguson, Brett J

    2014-10-01

    Legume plants are capable of entering into a symbiotic relationship with rhizobia bacteria. This results in the formation of novel organs on their roots, called nodules, in which the bacteria capture atmospheric nitrogen and provide it as ammonium to the host plant. Complex molecular and physiological changes are involved in the formation and establishment of such nodules. Several phytohormones are known to play key roles in this process. Gibberellins (gibberellic acids; GAs), a class of phytohormones known to be involved in a wide range of biological processes (i.e., cell elongation, germination) are reported to be involved in the formation and maturation of legume nodules, highlighted by recent transcriptional analyses of early soybean symbiotic steps. Here, we summarize what is currently known about GAs in legume nodulation and propose a model of GA action during nodule development. Results from a wide range of studies, including GA application, mutant phenotyping, and gene expression studies, indicate that GAs are required at different stages, with an optimum, tightly regulated level being key to achieve successful nodulation. Gibberellic acids appear to be required at two distinct stages of nodulation: (i) early stages of rhizobia infection and nodule primordium establishment; and (ii) later stages of nodule maturation.

  16. Root nodule structure in Chamaecytisus podolicus

    Directory of Open Access Journals (Sweden)

    Monika Skawińska

    2017-06-01

    Full Text Available By means of microscopic analyses, it was shown that root nodules formed by Chamaecytisus podolicus exhibited all structural features typical for indeterminate nodules of temperate genistean shrubs: (i apical nodule meristem composed of infected and non-infected domains, (ii parenchymatous bacteroid-containing tissue with infected cells only resulting from mitotic activity of infected meristematic cells, (iii absence of infection threads, and (iv convoluted bacteroids singly enclosed in a symbiosome membrane. For the first time, it was shown that the nodule meristem is organized into longitudinal files of sister cells.

  17. Transcriptional networks leading to symbiotic nodule organogenesis.

    Science.gov (United States)

    Soyano, Takashi; Hayashi, Makoto

    2014-08-01

    The symbiosis with nitrogen-fixing bacteria leading to root nodules is a relatively recent evolutionary innovation and limited to a distinct order of land plants. It has long been a mystery how plants have invented this complex trait. However, recent advances in molecular genetics of model legumes has elucidated genes involved in the development of root nodules, providing insights into this process. Here we discuss how the de novo assembly of transcriptional networks may account for the predisposition to nodulate. Transcriptional networks and modes of gene regulation from the arbuscular mycorrhizal symbiosis, nitrate responses and aspects of lateral root development have likely all contributed to the emergence and development of root nodules.

  18. Mechanistic action of gibberellins in legume nodulation

    Institute of Scientific and Technical Information of China (English)

    Satomi Hayashi; Peter MGresshoff; Brett J.Ferguson

    2014-01-01

    Legume plants are capable of entering into a symbiotic relationship with rhizobia bacteria. This results in the formation of novel organs on their roots, cal ed nodules, in which the bacteria capture atmospheric nitrogen and provide it as ammonium to the host plant. Complex molecular and physiological changes are involved in the formation and establishment of such nodules. Several phytohormones are known to play key roles in this process. Gibberel ins (gibberel ic acids;GAs), a class of phytohormones known to be involved in a wide range of biological processes (i.e., cellelongation, germination) are reported to be involved in the formation and maturation of legume nodules, highlighted by recent tran-scriptional analyses of early soybean symbiotic steps. Here, we summarize what is currently known about GAs in legume nodulation and propose a model of GA action during nodule development. Results from a wide range of studies, including GA application, mutant phenotyping, and gene expression studies, indicate that GAs are required at different stages, with an optimum, tightly regulated level being key to achieve successful nodulation. Gibberel ic acids appear to be required at two distinct stages of nodulation:(i) early stages of rhizobia infection and nodule primordium establishment;and (i ) later stages of nodule maturation.

  19. A nodule-specific gene encoding a subtilisin-like protease is expressed in early stages of actinorhizal nodule development.

    NARCIS (Netherlands)

    Ribeiro, A.; Akkermans, A.D.L.; Kammen, van A.; Bisseling, T.; Pawlowski, K.

    1995-01-01

    To identify genes specifically expressed during early stages of actinorhizal nodule development, a cDNA library made from poly(A) RNA from root nodules of Alnus glutinosa was screened differentially with nodule and root cDNA, respectively. Seven nodule-enhanced and four nodule-specific cDNA clones

  20. The peculiar ultrasonographic and elastographic features of thyroid nodules after treatment with laser or radiofrequency: similarities and differences.

    Science.gov (United States)

    Andrioli, Massimiliano; Valcavi, Roberto

    2014-12-01

    The aim of percutaneous thermal ablation with laser (LA) or radiofrequency (RFA) is to reduce the volume of benign thyroid nodules. Little is known about ultrasonographic and elastographic appearances of thyroid lesions after treatment. For the first time, we report in detail the main ultrasonographic and elastographic characteristics of thermally ablated nodules and their underlying similarities and differences. Both thermal treatments usually produce a marked hypoechoic area of coagulative necrosis. LA-treated lesions usually become highly heterogeneous due to the presence of cavitations and charring; they then evolve into hyperechoic scars. In RFA-treated nodules, instead, the necrotic area is more homogeneous but presents more irregular margins compared to those observed in LA-treated lesions. Regardless of the thermal method used, vascularity is typically reduced in all treated nodules and stiffness, evaluated with qualitative elastography, increases. In conclusion, ultrasonographic and elastographic appearances of the thermally ablated thyroid lesions differ slightly according to the adopted procedure. Furthermore, they are peculiar, changeable over time, and potentially misleading.

  1. Compressible Turbulent Flow Numerical Simulations of Tip Vortex Cavitation

    NARCIS (Netherlands)

    Khatami, F.; Weide, van der E.T.A.; Hoeijmakers, H.W.M.

    2015-01-01

    For an elliptic Arndt’s hydrofoil numerical simulations of vortex cavitation are presented. An equilibrium cavitation model is employed. This single-fluid model assumes local thermodynamic and mechanical equilibrium in the mixture region of the flow, is employed. Furthermore, for characterizing the

  2. Pressure and velocity dependence of flow-type cavitation erosion

    CSIR Research Space (South Africa)

    Auret, JG

    1993-12-01

    Full Text Available of underpressure expands for the higher velocity vOz. Thus cavitation bubbles leave this region farther downstream and the erosion zone shifts down- stream. At the same time, cavitation damage will in- crease because of the larger...

  3. Cavitation Measurement during Sonic and Ultrasonic Activated Irrigation

    NARCIS (Netherlands)

    Macedo, R.G.; Verhaagen, B.; Fernandez Rivas, David; Versluis, Andreas Michel; Wesselink, P.R.; van der Sluis, L.W.M.

    2014-01-01

    Introduction The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods The amount of cavitation generated around several endodontic instruments was measured

  4. Cavitation measurement during sonic and ultrasonic activated irrigation

    NARCIS (Netherlands)

    Macedo, R.; Verhaagen, B.; Fernandez Rivas, D.; Versluis, M.; Wesselink, P.; van der Sluis, L.

    2014-01-01

    Introduction The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods The amount of cavitation generated around several endodontic instruments was measured

  5. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the

  6. VibroCav: Hydrodynamic Vibration and Cavitation Technology

    NARCIS (Netherlands)

    Bakker, T.W.

    2012-01-01

    Vibration and cavitation can be generated in many ways and serve many useful purposes. This study describes physical aspects of useful vibration and cavitation for a broad spectrum of applications at atmospheric or elevated pressures. After a review of available devices, hydrodynamic vibrating-body

  7. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the conditi

  8. Suppression of Fatigue Crack Propagation of Duralumin by Cavitation Peening

    Directory of Open Access Journals (Sweden)

    Hitoshi Soyama

    2015-08-01

    Full Text Available It was demonstrated in the present paper that cavitation peening which is one of the mechanical surface modification technique can suppress fatigue crack propagation in duralumin. The impacts produced when cavitation bubble collapses can be utilised for the mechanical surface modification technique in the same way as laser peening and shot peening, which is called “cavitation peening”. Cavitation peening employing a cavitating jet in water was used to treat the specimen made of duralumin Japanese Industrial Standards JIS A2017-T3. After introducing a notch, fatigue test was conducted by a load-controlled plate bending fatigue tester, which has been originally developed. The fatigue crack propagation behavior was evaluated and the relationship between the fatigue crack propagation rate versus stress intensity factor range was obtained. From the results, the fatigue crack propagation rate was drastically reduced by cavitation peening and the fatigue life of duralumin plate was extended 4.2 times by cavitation peening. In addition, the fatigue crack propagation can be suppressed by 88% in the stable crack propagation stage by cavitation peening.

  9. Examples of oil cavitation erosion in positive displacement pumps

    Science.gov (United States)

    Halat, J. A.; Ellis, G. O.

    1974-01-01

    The effects of cavitation flow on piston type, positive displacement, hydraulic pumps are discussed. The operating principles of the pump and the components which are most subject to erosion effects are described. The mechanisms of cavitation phenomena are identified from photographic records. Curves are developed to show the solubility of air in water, oil-water emulsion, and industrial hydraulic oil.

  10. Progress in numerical simulation of cavitating water jets

    Institute of Scientific and Technical Information of China (English)

    PENG Guoyi; SHMIZU Seiji

    2013-01-01

    This paper reviews recent progress made toward modeling of cavitation and numerical simulation of cavitating water jets.Properties of existing cavitation models are discussed and a compressible mixture flow method for the numerical simulation of highspeed water jets accompanied by intensive cavitation is introduced.Two-phase fluids media of cavitating flow are treated as a homogeneous bubbly mixture and the mean flow is computed by solving Reynolds-Averaged Navier-Stokes (RANS) equations for compressible fluid.The intensity of cavitation is evaluated by the gas volume fraction,which is governed by the compressibility of bubble-liquid mixture corresponding to the status of mean flow field.Numerical results of cavitating water jet issuing from an orifice nozzle are presented and its applicability to intensively cavitating jets is demonstrated.However,the effect of impact pressure caused by collapsing of bubbles is neglected,and effectively coupling of the present compressible mixture flow method with the dynamics of bubbles remains to be a challenge.

  11. 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 cavitat

  12. Cavitation Measurement during Sonic and Ultrasonic Activated Irrigation

    NARCIS (Netherlands)

    Macedo, R.G.; Verhaagen, B.; Fernandez-Rivas, D.; Versluis, M.; Wesselink, P.R.; Sluis, van der L.W.M.

    2014-01-01

    Introduction The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods The amount of cavitation generated around several endodontic instruments was measure

  13. Cavitation measurement during sonic and ultrasonic activated irrigation

    NARCIS (Netherlands)

    Macedo, R.; Verhaagen, B.; Fernandez Rivas, D.; Versluis, M.; Wesselink, P.; van der Sluis, L.

    2014-01-01

    Introduction The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods The amount of cavitation generated around several endodontic instruments was measured

  14. Rudder gap cavitation: Fundamental understanding and its suppression devices

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Shin Hyung, E-mail: shr@snu.ac.k [Department of Naval Architecture and Ocean Engineering, Research Institute of Marine Systems Engineering, Seoul National University, 599 Gwanangno, Gwanak-ku, Seoul 151-744 (Korea, Republic of); Lee, Changmin; Lee, Hee Bum [Department of Naval Architecture and Ocean Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Oh, Jungkeun [Jungseok Research Institute of International Logistics and Trade, Inha University, Incheon 402-751 (Korea, Republic of)

    2010-08-15

    With the increasing size and speed of cargo ships, which results in high speed flow in propeller slipstream, cavitation is frequently observed on and around the rudder system. Among the various types of cavitation on the rudder system, the rudder gap cavitation is the most difficult one to control and suppress. For the development of rudder gap cavitation suppression devices, both experimental and numerical analyses of the physical phenomenon are warranted. In the present study, experiments of the incipient cavitation and pressure measurement were carried out for typical cargo ship rudder sections with and without the suppression devices, which were suggested by the author. The experiments were simulated using computational fluid dynamics tools and the results were compared in terms of the cavitation inception and surface pressure distribution. Fundamental understanding of the rudder gap cavitation inception was obtained along with its relevance to the surface pressure distribution. It is confirmed that the gap flow blocking devices effectively suppress the rudder gap cavitation and, at the same time, augment lift.

  15. VibroCav: Hydrodynamic Vibration and Cavitation Technology

    NARCIS (Netherlands)

    Bakker, T.W.

    2012-01-01

    Vibration and cavitation can be generated in many ways and serve many useful purposes. This study describes physical aspects of useful vibration and cavitation for a broad spectrum of applications at atmospheric or elevated pressures. After a review of available devices, hydrodynamic vibrating-body

  16. Ultrasound elastography in the diagnostic evaluation of indeterminate thyroid nodule

    Directory of Open Access Journals (Sweden)

    Sherif Fathy Abdelrahman

    2015-09-01

    Conclusion: Thyroid nodules with suspicious US criteria can be evaluated by US elastography that seems to be a useful addition for the assessment of such indeterminate nodules. It may reduce FNAC or select a nodule for aspiration.

  17. 电视胸腔镜手术诊断和治疗高龄小结节非小细胞肺癌%Video-assisted Thoracoscopic Surgery for the Diagnosis and Treatment of Small-nodule Non-small Cell Lung Cancer in Elderly Patients

    Institute of Scientific and Technical Information of China (English)

    董庆; 辛衍忠; 赵桂彬; 韩敬泉; 张凯; 刘成; 崔键

    2012-01-01

    Objective To evaluate the efficacy of video-assisted thoracoscopic surgery(VATS) for diagnosis and treatment of small-nodule non-small cell lung cancer ( snNSCLC) in elderly patients. Methods Under CT guidance, hookwire was used preoperatively to localize snNSCLC in 32 patients (71 - 85 years old) from January 2008 to June 2011, and then segmentectomy, lobeclomy, or wedge resection (1.5 cm from the tumor edge) was performed by VATS based on fast frozen sections. Results The procedure was completed in (185.5 ±34. 6)min, and the mean blood loss was (90. 6 ± 58. 3) ml. A mean of (7. 8 ±3. 8) lymph nodes were resected during the operation. All the patients were diagnosed with primary lung cancer. None of them died during the procedure. After the surgery, 3 patients developed pulmonary infection, 4 had atelectasis, and one showed atrial fibrillation, all of them were cured. The mean duration for chest drainage was(2.2 ± 1.6)d; and the mean drainage volume was(226.8 ±48. 5)ml/d. Postoperative pathology showed squamous cell cancer in 5 cases and adenocarcinotna in 27; 28 of the cases were in T1aN0M0, and 4 were in T1aN1M0. The mean hospital stay was (8.6 ±2.7)d. Among the 32 cases, follow-up was achieved in 31 of them for 2 to 42 months with a medium of 21. 5 months, during which 26 patients survived without tumor, 5 patients showed metastasis or recurrent tumor in 6 - 20 months (pleural metastasis in one case, brain metastasis in one, bone metastasis in one, and pulmonary metastasis in 2). Conclusion VATS is feasible and safe for diagnosis of snNSCLC in elderly patients with the healthy lung tissues been retained to the utmost.%目的 探讨电视胸腔镜手术(video-assisted thoracoscopic surgery,VATS)诊治高龄小结节非小细胞肺癌(small nodules non-small cell lung cancer,snNSCLC)的价值. 方法 2008年1月~2011年6月32例(71 ~85岁)snNSCLC术前CT引导下带钩钢丝体表定位,经电视胸腔镜应用内镜缝合切割器切除病灶,术中

  18. Elastosonographic evaluation of thyroid nodules in acromegaly.

    Science.gov (United States)

    Scacchi, Massimo; Andrioli, Massimiliano; Carzaniga, Chiara; Vitale, Giovanni; Moro, Mirella; Poggi, Luca; Pecori Giraldi, Francesca; Fatti, Letizia M; Cavagnini, Francesco

    2009-10-01

    Ultrasound-elastography (US-E) appears to be a helpful tool for the diagnosis of thyroid cancer. In acromegaly, the prevalence of thyroid cancer is still debated. The aims of this study were to evaluate thyroid nodules in acromegaly and to establish the accuracy of US-E in providing information on their nature, using cytological analysis as a reference. US-E was applied to 90 nodules detected in 25 acromegalic patients and to 94 nodules found in 31 non-acromegalic goitrous subjects. The lesions were classified according to the elasticity scores (ES) as soft (ES 1-2) or hard (ES 3-4). Fine needle aspiration cytology could be performed in 60.8% of hard nodules in acromegalics and in 86.7% of hard nodules in controls. The prevalence of hard nodules was significantly higher in the whole group of acromegalic patients than in controls (56.8 vs 16.0%, P<0.0001). The prevalence of hard nodules in patients with active acromegaly (68.9%) was greater, though not to a statistically significant extent, than that observed in cured (44.4%) and controlled (52.5%) patients. Cytology revealed malignancy or suspect malignancy in four of the nodules of non-acromegalic subjects and in none of the nodules of acromegalic patients. This study has demonstrated a high prevalence of stiff thyroid nodules in acromegaly, greater than that found in non-acromegalic goitrous subjects. In acromegalics, hard nodules appeared not to be malignant on cytopathological examination and are probably of fibrous nature. Thus, US-E appears to be of limited value for the diagnosis of thyroid cancer in acromegaly.

  19. Diagnostic work-up of pulmonary nodules. Management of pulmonary nodules detected with low-dose CT screening; Abklaerung von Lungenrundherden. Management durch Frueherkennungsuntersuchungen detektierter pulmonaler Rundherde

    Energy Technology Data Exchange (ETDEWEB)

    Wormanns, D. [Evangelische Lungenklinik Berlin, Berlin (Germany)

    2016-09-15

    Pulmonary nodules are the most frequent pathological finding in low-dose computed tomography (CT) scanning for early detection of lung cancer. Early stages of lung cancer are often manifested as pulmonary nodules; however, the very commonly occurring small nodules are predominantly benign. These benign nodules are responsible for the high percentage of false positive test results in screening studies. Appropriate diagnostic algorithms are necessary to reduce false positive screening results and to improve the specificity of lung cancer screening. Such algorithms are based on some of the basic principles comprehensively described in this article. Firstly, the diameter of nodules allows a differentiation between large (>8 mm) probably malignant and small (<8 mm) probably benign nodules. Secondly, some morphological features of pulmonary nodules in CT can prove their benign nature. Thirdly, growth of small nodules is the best non-invasive predictor of malignancy and is utilized as a trigger for further diagnostic work-up. Non-invasive testing using positron emission tomography (PET) and contrast enhancement as well as invasive diagnostic tests (e.g. various procedures for cytological and histological diagnostics) are briefly described in this article. Different nodule morphology using CT (e.g. solid and semisolid nodules) is associated with different biological behavior and different algorithms for follow-up are required. Currently, no obligatory algorithm is available in German-speaking countries for the management of pulmonary nodules, which reflects the current state of knowledge. The main features of some international and American recommendations are briefly presented in this article from which conclusions for the daily clinical use are derived. (orig.) [German] Lungenrundherde sind die haeufigsten pathologischen Befunde bei Untersuchungen mit der Niedrigdosis-CT zur Lungenkrebsfrueherkennung. Fruehstadien des Lungenkarzinoms manifestieren sich meist als Rundherd

  20. Solitary pulmonary nodule and 18F-FDG PET/CT. Part 2: accuracy, cost-effectiveness, and current recommendations*

    Science.gov (United States)

    Mosmann, Marcos Pretto; Borba, Marcelle Alves; de Macedo, Francisco Pires Negromonte; Liguori, Adriano de Araujo Lima; Villarim Neto, Arthur; de Lima, Kenio Costa

    2016-01-01

    A solitary pulmonary nodule is a common, often incidental, radiographic finding. The investigation and differential diagnosis of solitary pulmonary nodules remain complex, because there are overlaps between the characteristics of benign and malignant processes. There are currently many strategies for evaluating solitary pulmonary nodules. The main objective is to identify benign lesions, in order to avoid exposing patients to the risks of invasive methods, and to detect cases of lung cancer accurately, in order to avoid delaying potentially curative treatment. The focus of this study was to review the evaluation of solitary pulmonary nodules, to discuss the current role of 18F-fluorodeoxyglucose positron-emission tomography, addressing its accuracy and cost-effectiveness, and to detail the current recommendations for the examination in this scenario. PMID:27141133

  1. NUMERICAL VALIDATION OF COMPUTATIONAL MODEL FOR SHEET CAVITATING FLOWS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A computational modeling for the sheet cavitating flows is presented. The cavitation model is implemented in a viscous Navier-Stokes solver. The cavity interface and shape are determined using an iterative procedure matching the cavity surface to a constant pressure boundary. The pressure distribution, as well as its gradient on the wall, is taken into account in updating the cavity shape iteratively. Numerical computations are performed for the sheet cavitating flows at a range of cavitation numbers across the hemispheric headform/cylinder body with different grid numbers. The influence of the relaxation factor in the cavity shape updating scheme for the algorithm accuracy and reliability is conducted through comparison with other two cavity shape updating numerical schemes.The results obtained are reasonable and the iterative procedure of cavity shape updating is quite stable, which demonstrate the superiority of the proposed cavitation model and algorithms.

  2. Analysis on Velocity Characteristics of Cavitation Flow Around Hydrofoil

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-bin; LIU Shu-yan; WANG Guo-yu; ZHANG Bo; ZHANG Min-di

    2010-01-01

    The time-averaged velocity distributions in flows around a hydronautics hydrofoil were measured by using a digit-al particle image velocimeter (DPIV) system. The results show that the velocity distribution in the whole flow field depends on the development of cavitation structures with the decreasing of cavitation number. The high-fluctuation region with lower velocity relates to the cavitation area. The lowest velocity distribution in the cavity core becomes more uniform, and its in-fluence becomes smaller gradually as moving to downstream. The main-stream velocity distribution is even, then fluctuate and even at last. In the supercavitation stage, the fluid velocity in the cavitation region, corresponding to the front of the hydrofoil's suction surface, has a distribution close to the main stream, while the fluid velocity in other cavitation area is lower.

  3. Study of the cavitating instability on a grooved Venturi profile

    CERN Document Server

    Danlos, Amélie; Ravelet, Florent; Coutier-Delgosha, Olivier; Bakir, Farid

    2012-01-01

    Cavitation is a limiting phenomenon in many domains of fluid mechanics. Instabilities of a partial cavity developed on an hydrofoil, a converging-diverging step or in an inter-blade channel in turbomachinery, have already been investigated and described in many previous works. The aim of this study is to evaluate a passive control method of the sheet cavity. According to operating conditions, cavitation can be described by two different regimes: an unstable regime with a cloud cavitation shedding and a stable regime with only a pulsating sheet cavity. Avoiding cloud cavitation can limit structure damages since a pulsating sheet cavity is less agressive. The surface condition of a converging-diverging step, like a Venturi-type obstacle, is here studied as a solution for a passive control of the cavitation. This study discusses the effect of an organized roughness, in the shape of longitudinal grooves, on the developed sheet cavity. Analyzes conducted with Laser Doppler Velocimetry, visualisations and pressure ...

  4. A THERMODYNAMIC CAVITATION MODEL APPLICABLE TO HIGH TEMPERATURE FLOW

    Directory of Open Access Journals (Sweden)

    De-Min Liu

    2011-01-01

    Full Text Available Cavitation is not only related with pressure, but also affected by temperature. Under high temperature, temperature depression of liquids is caused by latent heat of vaporization. The cavitation characteristics under such condition are different from those under room temperature. The paper focuses on thermodynamic cavitation based on the Rayleigh-Plesset equation and modifies the mass transfer equation with fully consideration of the thermodynamic effects and physical properties. To validate the modified model, the external and internal flow fields, such as hydrofoil NACA0015 and nozzle, are calculated, respectively. The hydrofoil NACA0015's cavitation characteristic is calculated by the modified model at different temperatures. The pressure coefficient is found in accordance with the experimental data. The nozzle cavitation under the thermodynamic condition is calculated and compared with the experiment.

  5. Cavitation characteristics of pit structure in ultrasonic field

    Institute of Scientific and Technical Information of China (English)

    BAI LiXin; XU WeiLin; ZHANG FaXing; LI NaiWen; ZHANG YiChi; HUANG DeFa

    2009-01-01

    Bubble collecting, bubble holding and micro-bubble ejecting characteristics of pit structure and the influence of cavitation bubble on the development of erosion pit are investigated by means of highspeed photography experiments. Pits tend to collect and hold wandering cavitation bubbles. The air holding phenomenon of pits can be a destination of the incubation period in the process of cavitation erosion. The holding bubble tends to eject micro-bubbles from the top of holding cavitation bubble,making the pit a source of nuclei. With bubbles being held in pits, the diameters of pits increase rapidly.But in the given experiment condition, there is a specific stable value beyond which the diameter of pits will not increase. This characteristic will be helpful in understanding and predicting the cavitation erosion process.

  6. Effect of cavitation bubble collapse on hydraulic oil temperature

    Institute of Scientific and Technical Information of China (English)

    沈伟; 张健; 孙毅; 张迪嘉; 姜继海

    2016-01-01

    Cavitation bubble collapse has a great influence on the temperature of hydraulic oil. Herein, cone-type throttle valve experiments are carried out to study the thermodynamic processes of cavitation. First, the processes of growth and collapse are analysed, and the relationships between the hydraulic oil temperature and bubble growth and collapse are deduced. The effect of temperature is then considered on the hydraulic oil viscosity and saturated vapour pressure. Additionally, an improved form of the Rayleigh–Plesset equation is developed. The effect of cavitation on the hydraulic oil temperature is experimentally studied and the effects of cavitation bubble collapse in the hydraulic system are summarised. Using the cone-type throttle valve as an example, a method to suppress cavitation is proposed.

  7. Characteristic analysis of unsteady viscous flow around a cavitating propeller

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on viscous multiphase flow theory, this paper presents some recent validation results with a hybrid grid and sliding mesh solving Unsteady Navier-Stokes (N-S) and Bubble Dynamics equations as applied to prediction of pressure, velocity and vapor volume fraction in the wake in an uniform inflow. Comparable to experimental results, numerical predictions of sheet cavitation, tip vortex cavitation and hub vortex cavitation are in agreement with the corresponding experimental data, the same as numerical predictions of pressure in wake. Tip vortex cavitation is the most important to generate the pressure fluctuation within the near wake. The characteristics such as blade and shaft rate frequency of propeller pressure in wake coincide with its geometric model and parameters. With increasing distance from propeller disk, the pressure signals at blade frequency de-crease. The process of attenuation becomes fast with the decreased advance coefficient and cavitation number.

  8. Flow and cavitation characteristics of water hydraulic poppet valves

    Institute of Scientific and Technical Information of China (English)

    廖义德; 刘银水; 黄艳; 李壮云

    2002-01-01

    Two types of poppet valves were tested, one is a poppet with a sharp-edged seats, and the other is that with a chamfered seat. During the tests, the effects of backpressure and poppet lift on flow characteristics were considered. Cavitation inception was detected by the appearance and rapid growth of a particular low frequency component of the outlet pressure fluctuation of valve when cavitation occurs. Experimental results show cavitation, back pressure, valve opening and its geometrical shape have significant effects on the flow characteristics of valve. The flow coefficient of throttle with water used as working medium is 0. 85~0. 95 when there is no cavitation. The pressure drop of flow saturation decreases with the increasing of poppet lift. The sharp-edged throttle has stronger anti-cavitation ability than the chamfered one.

  9. A PRESSURE-BASED ALGORITHM FOR CAVITATING FLOW COMPUTATIONS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ling-xin; ZHAO Wei-guo; SHAO Xue-ming

    2011-01-01

    A pressure-based algorithm for the prediction of cavitating flows is presented. The algorithm employs a set of equations including the Navier-Stokes equations and a cavitation model explaining the phase change between liquid and vapor. A pressure-based method is used to construct the algorithm and the coupling between pressure and velocity is considered. The pressure correction equation is derived from a new continuity equation which employs a source term related to phase change rate instead of the material derivative of density Dp/Dt.Thispressure-based algorithm allows for the computation of steady or unsteady,2-Dor 3-D cavitating flows. Two 2-D cases, flows around a flat-nose cylinder and around a NACA0015 hydrofoil, are simulated respectively, and the periodic cavitation behaviors associated with the re-entrant jets are captured. This algorithm shows good capability of computating time-dependent cavitating flows.

  10. Role of baseline nodule density and changes in density and nodule features in the discrimination between benign and malignant solid indeterminate pulmonary nodules

    NARCIS (Netherlands)

    Xu, D.M.; van Klaveren, R.J.; de Bock, G.H.; Leusveld, A.L.M.; Dorrius, M.D.; Zhao, Y.; Wang, Y.; de Koning, H.J.; Scholten, E.T.; Verschakelen, J.; Prokop, M.; Oudkerk, M.

    2009-01-01

    Purpose: To retrospectively evaluate whether baseline nodule density or changes in density or nodule features could be used to discriminate between benign and malignant solid indeterminate nodules. Materials and methods: Solid indeterminate nodules between 50 and 500 mm(3) (4.6-9.8 mm) were assessed

  11. Correlation coefficient based supervised locally linear embedding for pulmonary nodule recognition.

    Science.gov (United States)

    Wu, Panpan; Xia, Kewen; Yu, Hengyong

    2016-11-01

    Dimensionality reduction techniques are developed to suppress the negative effects of high dimensional feature space of lung CT images on classification performance in computer aided detection (CAD) systems for pulmonary nodule detection. An improved supervised locally linear embedding (SLLE) algorithm is proposed based on the concept of correlation coefficient. The Spearman's rank correlation coefficient is introduced to adjust the distance metric in the SLLE algorithm to ensure that more suitable neighborhood points could be identified, and thus to enhance the discriminating power of embedded data. The proposed Spearman's rank correlation coefficient based SLLE (SC(2)SLLE) is implemented and validated in our pilot CAD system using a clinical dataset collected from the publicly available lung image database consortium and image database resource initiative (LICD-IDRI). Particularly, a representative CAD system for solitary pulmonary nodule detection is designed and implemented. After a sequential medical image processing steps, 64 nodules and 140 non-nodules are extracted, and 34 representative features are calculated. The SC(2)SLLE, as well as SLLE and LLE algorithm, are applied to reduce the dimensionality. Several quantitative measurements are also used to evaluate and compare the performances. Using a 5-fold cross-validation methodology, the proposed algorithm achieves 87.65% accuracy, 79.23% sensitivity, 91.43% specificity, and 8.57% false positive rate, on average. Experimental results indicate that the proposed algorithm outperforms the original locally linear embedding and SLLE coupled with the support vector machine (SVM) classifier. Based on the preliminary results from a limited number of nodules in our dataset, this study demonstrates the great potential to improve the performance of a CAD system for nodule detection using the proposed SC(2)SLLE. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Cavitation instability in bulk metallic glasses

    Directory of Open Access Journals (Sweden)

    Dai L.H.

    2015-01-01

    Full Text Available Recent experiments have shown that fracture surfaces of bulk metallic glasses (BMGs usually exhibit an intriguing nanoscale corrugation like fractographic feature mediated by nanoscale void formation. We attribute the onset of this nanoscale corrugation to TTZs (tension transformation zones mediated cavitation. In our recent study, the spall experiments of Zr-based BMG using a single-stage light gas gun were performed. To uncover the mechanisms of the spallation damage nucleation and evolution, the samples were designed to be subjected to dynamic tensile loadings of identical amplitude but with different durations by making use of the multi-stress pulse and the double-flyer techniques. It is clearly revealed that the macroscopic spall fracture in BMGs originates from the nucleation, growth and coalescence of micro-voids. Then, a microvoid nucleation model of BMGs based on free volume theory is proposed, which indicates that the nucleation of microvoids at the early stage of spallation in BMGs is resulted from diffusion and coalescence of free volume. Furthermore, a theoretical model of void growth in BMGs undergoing remote dynamic hydrostatic tension is developed. The critical condition of cavitation instability is obtained. It is found that dynamic void growth in BMGs can be well controlled by a dimensionless inertial number characterizing the competition between intrinsic and extrinsic time scales. To unveil the atomic-level mechanism of cavitation, a systematic molecular dynamics (MD simulation of spallation behaviour of a binary metallic glass with different impact velocities was performed. It is found that micro-void nucleation is determined TTZs while the growth is controlled by shear transformation zones (STZs at atomic scale.

  13. Peripapillary intrachoroidal cavitation in pathological myopia.

    Science.gov (United States)

    Marticorena-Álvarez, P; Clement-Fernández, F; Iglesias-Ussel, L

    2014-08-01

    A 54 year old woman with pathological myopia, presented with an elevated, yellowish-white lesion at the inferior border of the myopic conus in her left eye. The optical coherence tomography (OCT) demonstrated an intrachoroidal hyporeflective space. The fluorescein angiography examination (FA) showed early hypofluorescence with delayed staining, with no leakage of contrast. Recognition of «peripapillary intrachoroidal cavitation» as an own entity associated with pathological myopia is important to avoid confusion with other possible retinal lesions which require further investigation and treatment. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  14. Cavitation erosion of copper and aluminium in water at elevated-temperature

    CSIR Research Space (South Africa)

    Auret, JG

    1993-12-01

    Full Text Available Cavitation erosion tests were carried out in tap water on aluminium and copper samples in a rotating disk cavitations test apparatus, to study the effect of water temperature on cavitation dynamics and cavitation erosion. A shift in the position...

  15. The clinical value of CT guidance Hook-wire positioning thoracoscopic surgery for ground-glass opacity lung nodules%术前CT引导下Hook-wire定位胸腔镜切除肺毛玻璃样结节临床研究

    Institute of Scientific and Technical Information of China (English)

    邓俊; 仲宁; 陈文

    2016-01-01

    目的:探讨CT引导下Hook-wire术前定位肺磨玻璃样结节(GGO)在胸腔镜切除术中的应用。方法:25例肺GGO患者均术前行Hook-wire定位,行胸腔镜肺楔形切除术。根据术中冰冻病理结果决定下一步治疗方式。结果:肺GGO直径为(11.48±3.50)mm,距离壁层胸膜(16.52±5.98)mm。CT引导肺GGO Hook-wire定位均成功,定位时间(15.04±3.38)min,出现微量气胸5例(占20%),均不需放置引流管,1例出现少许肺实质出血(占4.00%),无一例出现定位针脱落,实施胸腔镜肺楔形切除100%,其中12例单纯行胸腔镜肺楔形切除手术时间为(21.67±3.94)min,13例为浸润性腺癌,行胸腔镜肺叶或是肺段切除及淋巴结清扫术,手术时间为(58.84±12.01)min。结论:术前CT引导下Hook-wire定位是一种安全可靠且容易掌握的临床技术,降低了手术时间,并发症少,值得临床推广应用。%Objective: To evaluate the clinical application of guidance Hook-wire positioning for ground-glass opacity before video-assisted thoracoscopic resection.Methods: Preoperative location of 25 patients with ground-glass opacity lung nodules was performed using CT-guided Hook-wire technique. Video assisted tho-racic surgery (VATS) pulmonary wedge resection was adopted. According to the result of intraoperative frozen pathology, the next mode of operation was adopted.Results: GGO diameter (11.48±3.50) mm, diatance from the parietal pleura (16.52±5.98) mm. Twenty ifve patients were successfully located. The mean procedure time for preoperative CT-guided Hook-wire location was (15.04±3.38) min. 5 patients had micro pneumothroax after positioning. The chest tube drainage was not required. One patient had minimal needle tract parenchymal hemor-rhages. No one occured migration and fall out of the hookwire. VATS wedge resection surgery successful rate was 100%. Twelve cases of pure thoracoscopy pulmonary wedge

  16. Indeterminate Pulmonary Nodules at Colorectal Cancer Staging

    DEFF Research Database (Denmark)

    Nordholm-Carstensen, Andreas; Wille-Jørgensen, Peer A; Jorgensen, Lars N

    2013-01-01

    This study aimed to estimate the prevalence of indeterminate pulmonary nodules and specific radiological and clinical characteristics that predict malignancy of these at initial staging chest computed tomography (CT) in patients with colorectal cancer. A considerable number of indeterminate...... pulmonary nodules, which cannot readily be classified as either benign or malignant, are detected at initial staging chest CT in colorectal cancer patients....

  17. Pulmonary nodule detection with digital projection radiography: an ex-vivo study on increased latitude post-processing.

    Science.gov (United States)

    Biederer, Juergen; Gottwald, Tobias; Bolte, Hendrik; Riedel, Christian; Freitag, Sandra; Van Metter, Richard; Heller, Martin

    2007-04-01

    To evaluate increased image latitude post-processing of digital projection radiograms for the detection of pulmonary nodules. 20 porcine lungs were inflated inside a chest phantom, prepared with 280 solid nodules of 4-8 mm in diameter and examined with direct radiography (3.0x2.5 k detector, 125 kVp, 4 mAs). Nodule position and size were documented by CT controls and dissection. Four intact lungs served as negative controls. Image post-processing included standard tone scales and increased latitude with detail contrast enhancement (log-factors 1.0, 1.5 and 2.0). 1280 sub-images (512x512 pixel) were centred on nodules or controls, behind the diaphragm and over free parenchyma, randomized and presented to six readers. Confidence in the decision was recorded with a scale of 0-100%. Sensitivity and specificity for nodules behind the diaphragm were 0.87/0.97 at standard tone scale and 0.92/0.92 with increased latitude (log factor 2.0). The fraction of "not diagnostic" readings was reduced (from 208/1920 to 52/1920). As an indicator of increased detection confidence, the median of the ratings behind the diaphragm approached 100 and 0, respectively, and the inter-quartile width decreased (controls: pimage latitude. Above the diaphragm, accuracy and detection confidence remained unchanged. Here, the sensitivity for nodules was 0.94 with a specificity from 0.96 to 0.97 (all p>0.05). Increased latitude post-processing has minimal effects on the overall accuracy, but improves the detection confidence for sub-centimeter nodules in the posterior recesses of the lung.

  18. Numerical 3D analysis of cloud cavitation shedding frequency on a circular leading edge hydrofoil with a barotropic cavitation model

    Science.gov (United States)

    Blume, M.; Skoda, R.

    2015-12-01

    A compressible density-based time-explicit low Mach number consistent viscous flow solver is utilised in combination with a barotropic cavitation model for the analysis of cloud cavitation on a circular leading edge (CLE) hydrofoil. For 5° angle of attack, cloud structure and shedding frequency for different cavitation numbers are compared to experimental data. A strong grid sensitivity is found in particular for high cavitation numbers. On a fine grid, a very good agreement with validation data is achieved even without explicit turbulence model. The neglect of viscous effects as well as a two-dimensional set-up lead to a less realistic prediction of cloud structures and frequencies. Comparative simulations with the Sauer-Schnerr cavitation model and modified pre-factors of the mass transfer terms underestimate the measured shedding frequency.

  19. Benign solitary solid cold thyroid nodules

    DEFF Research Database (Denmark)

    Døssing, Helle; Bennedbaek, Finn Noe; Karstrup, Steen;

    2002-01-01

    PURPOSE: To evaluate the effects of ultrasonography (US)-guided interstitial laser photocoagulation (ILP) on the volume of benign solitary solid cold thyroid nodules and any nodule-related symptoms. MATERIALS AND METHODS: ILP was performed in 16 patients with normal thyroid function and a solid...... to evaluate the size of the untreated thyroid nodule. RESULTS: In the 16 patients treated with ILP, the mean thyroid nodule volume decreased from 10 to 5.4 mL (P .... Pressure symptoms were significantly reduced (P =.0002) after 6 months. The treatment was well-tolerated in all patients. No significant change in thyroid nodule volume was seen in the control group. CONCLUSION: US-guided ILP could become a useful nonsurgical alternative in the treatment of the benign...

  20. Current Diagnosis and Management of Thyroid Nodules

    Directory of Open Access Journals (Sweden)

    Tjokorda Gde Dalem Pemayun

    2016-11-01

    Full Text Available Thyroid nodules are frequently found. Although they are often palpable, many are found incidentally during unrelated radiographic studies. Ten to 15% of thyroid nodules represents thyroid malignancy. Clinician suc as an internist/endocrinologist have to  classify the nodule, stratify the risk of thyroid cancer, performed a diagnostic work-up, provide medical / non-surgical therapy, select candidates for surgery and provide appropriate follow-up that should last a lifetime. This article provide an up-date review of diagnostic approach and management of thyroid nodules, focusing on current algorithm in lights of the most recent published American Thyroid Association thyroid nodule and differentiated thyroid cancer management guidelines.

  1. An Official American Thoracic Society Research Statement: A Research Framework for Pulmonary Nodule Evaluation and Management.

    Science.gov (United States)

    Slatore, Christopher G; Horeweg, Nanda; Jett, James R; Midthun, David E; Powell, Charles A; Wiener, Renda Soylemez; Wisnivesky, Juan P; Gould, Michael K

    2015-08-15

    Pulmonary nodules are frequently detected during diagnostic chest imaging and as a result of lung cancer screening. Current guidelines for their evaluation are largely based on low-quality evidence, and patients and clinicians could benefit from more research in this area. In this research statement from the American Thoracic Society, a multidisciplinary group of clinicians, researchers, and patient advocates reviewed available evidence for pulmonary nodule evaluation, characterized six focus areas to direct future research efforts, and identified fundamental gaps in knowledge and strategies to address them. We did not use formal mechanisms to prioritize one research area over another or to achieve consensus. There was widespread agreement that novel tests (including novel imaging tests and biopsy techniques, biomarkers, and prognostic models) may improve diagnostic accuracy for identifying cancerous nodules. Before they are used in clinical practice, however, better evidence is needed to show that they improve more distal outcomes of importance to patients. In addition, the pace of research and the quality of clinical care would be improved by the development of registries that link demographic and nodule characteristics with patient-level outcomes. Methods to share data from registries are also necessary. This statement may help researchers to develop impactful and innovative research projects and enable funders to better judge research proposals. We hope that it will accelerate the pace and increase the efficiency of discovery to improve the quality of care for patients with pulmonary nodules.

  2. Comparison of computer-aided diagnosis performance and radiologist readings on the LIDC pulmonary nodule dataset

    Science.gov (United States)

    Zhao, Luyin; Lee, Michael C.; Boroczky, Lilla; Vloemans, Victor; Opfer, Roland

    2008-03-01

    One challenge facing radiologists is the characterization of whether a pulmonary nodule detected in a CT scan is likely to be benign or malignant. We have developed an image processing and machine learning based computer-aided diagnosis (CADx) method to support such decisions by estimating the likelihood of malignancy of pulmonary nodules. The system computes 192 image features which are combined with patient age to comprise the feature pool. We constructed an ensemble of 1000 linear discriminant classifiers using 1000 feature subsets selected from the feature pool using a random subspace method. The classifiers were trained on a dataset of 125 pulmonary nodules. The individual classifier results were combined using a majority voting method to form an ensemble estimate of the likelihood of malignancy. Validation was performed on nodules in the Lung Imaging Database Consortium (LIDC) dataset for which radiologist interpretations were available. We performed calibration to reduce the differences in the internal operating points and spacing between radiologist rating and the CADx algorithm. Comparing radiologists with the CADx in assigning nodules into four malignancy categories, fair agreement was observed (κ=0.381) while binary rating yielded an agreement of (κ=0.475), suggesting that CADx can be a promising second reader in a clinical setting.

  3. Bone suppressed images improve radiologists’ detection performance for pulmonary nodules in chest radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Schalekamp, Steven, E-mail: steven.schalekamp@gmail.com [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Ginneken, Bram van, E-mail: b.vanginneken@rad.umcn.nl [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Meiss, Louis, E-mail: L.Meiss@meandermc.nl [Meander Medical Centre, Utrechtseweg 160, 3800 BM Amersfoort (Netherlands); Peters-Bax, Liesbeth, E-mail: l.petersbax@rad.umcn.nl [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Quekel, Lorentz G.B.A., E-mail: Lgba.quekel@meandermc.nl [Meander Medical Centre, Utrechtseweg 160, 3800 BM Amersfoort (Netherlands); Snoeren, Miranda M., E-mail: m.snoeren@rad.umcn.nl [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Tiehuis, Audrey M., E-mail: am.tiehuis@meandermc.nl [Meander Medical Centre, Utrechtseweg 160, 3800 BM Amersfoort (Netherlands); Wittenberg, Rianne, E-mail: rianne_wittenberg@hotmail.com [Meander Medical Centre, Utrechtseweg 160, 3800 BM Amersfoort (Netherlands); Karssemeijer, Nico, E-mail: n.karssemeijer@rad.umcn.nl [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Schaefer-Prokop, Cornelia M., E-mail: cornelia.schaeferprokop@gmail.com [Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen (Netherlands); Meander Medical Centre, Utrechtseweg 160, 3800 BM Amersfoort (Netherlands)

    2013-12-01

    Objectives: To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs. Materials and methods: Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis. Results: ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03). Conclusion: Bone suppressed images improve radiologists’ detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.

  4. Semantics and image content integration for pulmonary nodule interpretation in thoracic computed tomography

    Science.gov (United States)

    Raicu, Daniela S.; Varutbangkul, Ekarin; Cisneros, Janie G.; Furst, Jacob D.; Channin, David S.; Armato, Samuel G., III

    2007-03-01

    Useful diagnosis of lung lesions in computed tomography (CT) depends on many factors including the ability of radiologists to detect and correctly interpret the lesions. Computer-aided Diagnosis (CAD) systems can be used to increase the accuracy of radiologists in this task. CAD systems are, however, trained against ground truth and the mechanisms employed by the CAD algorithms may be distinctly different from the visual perception and analysis tasks of the radiologist. In this paper, we present a framework for finding the mappings between human descriptions and characteristics and computed image features. The data in our study were generated from 29 thoracic CT scans collected by the Lung Image Database Consortium (LIDC). Every case was annotated by up to 4 radiologists by marking the contour of nodules and assigning nine semantic terms to each identified nodule; fifty-nine image features were extracted from each segmented nodule. Correlation analysis and stepwise multiple regression were applied to find correlations among semantic characteristics and image features and to generate prediction models for each characteristic based on image features. From our preliminary experimental results, we found high correlations between different semantic terms (margin, texture), and promising mappings from image features to certain semantic terms (texture, lobulation, spiculation, malignancy). While the framework is presented with respect to the interpretation of pulmonary nodules in CT images, it can be easily extended to find mappings for other modalities in other anatomical structures and for other image features.

  5. Experimental investigation of the flow-induced vibration of hydrofoils in cavitating flows

    Science.gov (United States)

    Wang, Guoyu; Wu, Qin; Huang, Biao; Gao, Yuan

    2015-12-01

    The objective of this paper is to investigate the correlation between fluid induced vibration and unsteady cavitation behaviours. Experimental results are presented for a modified NACA66 hydrofoil, which is fixed at α=8°. The high-speed camera is synchronized with a single point Laser Doppler Vibrometer to analyze the transient cavitating flow structures and the corresponding structural vibration characteristics. The results showed that, with the decreasing of the cavitation number, the cavitating flows in a water tunnel display several types of cavitation patterns, such as incipient cavitation, sheet cavitation and cloud cavitation. The cavity shedding frequency reduces with the decrease of the cavitation number. As for the cloud cavitation regime, the trend of the vibration velocity goes up with the growth of the attached cavity, accompanied with small amplitude fluctuations. Then the collapse and shedding of the large-scale cloud cavities leads to substantial increase of the vibration velocity fluctuations.

  6. Filter learning and evaluation of the computer aided visualization and analysis (CAVA) paradigm for pulmonary nodules using the LIDC-IDRI database

    Science.gov (United States)

    Wiemker, Rafael; Dharaiya, Ekta; Steinberg, Amnon; Buelow, Thomas; Saalbach, Axel; Vik, Torbjörn

    2010-03-01

    We present a simple rendering scheme for thoracic CT datasets which yields a color coding based on local differential geometry features rather than Hounsfield densities. The local curvatures are computed on several resolution scales and mapped onto different colors, thereby enhancing nodular and tubular structures. The rendering can be used as a navigation device to quickly access points of possible chest anomalies, in particular lung nodules and lymph nodes. The underlying principle is to use the nodule enhancing overview as a possible alternative to classical CAD approaches by avoiding explicit graphical markers. For performance evaluation we have used the LIDC-IDRI lung nodule data base. Our results indicate that the nodule-enhancing overview correlates well with the projection images produced from the IDRI expert annotations, and that we can use this measure to optimize the combination of differential geometry filters.

  7. Computerized comprehensive data analysis of Lung Imaging Database Consortium (LIDC)

    Energy Technology Data Exchange (ETDEWEB)

    Tan Jun; Pu Jiantao; Zheng Bin; Wang Xingwei; Leader, Joseph K. [Department of Radiology, Imaging Research Division, University of Pittsburgh, 3362 Fifth Avenue, Pittsburgh, Pennsylvania 15213 (United States)

    2010-07-15

    Purpose: Lung Image Database Consortium (LIDC) is the largest public CT image database of lung nodules. In this study, the authors present a comprehensive and the most updated analysis of this dynamically growing database under the help of a computerized tool, aiming to assist researchers to optimally use this database for lung cancer related investigations. Methods: The authors developed a computer scheme to automatically match the nodule outlines marked manually by radiologists on CT images. A large variety of characteristics regarding the annotated nodules in the database including volume, spiculation level, elongation, interobserver variability, as well as the intersection of delineated nodule voxels and overlapping ratio between the same nodules marked by different radiologists are automatically calculated and summarized. The scheme was applied to analyze all 157 examinations with complete annotation data currently available in LIDC dataset. Results: The scheme summarizes the statistical distributions of the abovementioned geometric and diagnosis features. Among the 391 nodules, (1) 365 (93.35%) have principal axis length {<=}20 mm; (2) 120, 75, 76, and 120 were marked by one, two, three, and four radiologists, respectively; and (3) 122 (32.48%) have the maximum volume overlapping ratios {>=}80% for the delineations of two radiologists, while 198 (50.64%) have the maximum volume overlapping ratios <60%. The results also showed that 72.89% of the nodules were assessed with malignancy score between 2 and 4, and only 7.93% of these nodules were considered as severely malignant (malignancy {>=}4). Conclusions: This study demonstrates that LIDC contains examinations covering a diverse distribution of nodule characteristics and it can be a useful resource to assess the performance of the nodule detection and/or segmentation schemes.

  8. EVALUATION OF THYROID NODULES: AN ULTRASONOGRAPHIC STUDY

    Directory of Open Access Journals (Sweden)

    Vijai

    2013-10-01

    Full Text Available ABSTRACT : Thyroid nodules are common in adults, with a reported prevalence of up to 50%. (1 – 5. Furthermore, 9% to 15% of nodules identified during clinical examinations are diagnosed as malignant (6 – 8. It is gen erally accepted that sonography and sonographically guided fine - needle aspiration cytologic examination are the modalities of choice for differentiating benign and malignant thyroid nodules (1 , 9 . Thyroid ultrasonography (USG is the major diagnostic moda lity for evaluating thyroid nodules. Using USG, a thyroid nodule appears as a nodular lesion within the thyroid gland that is distinguishable from the adjacent parenchyma. Several USG features, such as marked hypoechogenicity, irregular margin, micro calci fications, and a taller - than - wide shape have been introduced as potential predictors for the presence of thyroid malignancies. AIMS & OBJECTIVE : The aim of this study was to assess the accuracy of USG diagnosis for thyroid nodules. MATERIALS & METHODS: Th e present study was conducted in the Department of Radiodiagnosis, TMMC & RC, TMU, Moradabad. Patients under the study were referred from department of Surgery, Paediatrics, Medicine, ENT, Gynaecology and Obstetrics. Patients for the study were evaluated b y Clinical & Radiological examination. The total number of patients were 120. RESULT: On clinical examination, multiple nodules were found only in 17% of cases, whereas on USG, multiple nodules were found in 58%. 50% of clinically solitary nodules were d emonstrated to be multiple on USG. CONCLUSION: In conclusion, similar to the recent literature reviewed so far, for a large majority of patients, diagnosis changed after ultrasonography, so the results necessitate the use of ultrasonography, which is a non invasive method, as a complementary method to physical examination in the diagnosis of thyroid diseases, especially thyroid nodules.

  9. Catastrophic Cracking Courtesy of Quiescent Cavitation

    CERN Document Server

    Daily, D Jesse; Thomson, Scott L; Truscott, Tadd T

    2012-01-01

    A popular party trick is to fill a glass bottle with water and hit the top of the bottle with an open hand, causing the bottom of the bottle to break open. We investigate the source of the catastrophic cracking through the use of high-speed video and an accelerometer attached to the bottom of a glass bottle. Upon closer inspection, it is obvious that the acceleration caused by hitting the top of the bottle is followed by the formation of bubbles near the bottom. The nearly instantaneous acceleration creates an area of low pressure on the bottom of the bottle where cavitation bubbles form. Moments later, the cavitation bubbles collapse at roughly 10 times the speed of formation, causing the bottle to break. The accelerometer data shows that the bottle is broken after the bubbles collapse and that the magnitude of the bubble collapse is greater than the initial impact. The fluid dynamics video highlights that this trick will not work if the bottle is empty nor if it is filled with a carbonated fluid because the...

  10. Cavitation and pore blocking in nanoporous glasses.

    Science.gov (United States)

    Reichenbach, C; Kalies, G; Enke, D; Klank, D

    2011-09-06

    In gas adsorption studies, porous glasses are frequently referred to as model materials for highly disordered mesopore systems. Numerous works suggest that an accurate interpretation of physisorption isotherms requires a complete understanding of network effects upon adsorption and desorption, respectively. The present article deals with nitrogen and argon adsorption at different temperatures (77 and 87 K) performed on a series of novel nanoporous glasses (NPG) with different mean pore widths. NPG samples contain smaller mesopores and significantly higher microporosity than porous Vycor glass or controlled pore glass. Since the mean pore width of NPG can be tuned sensitively, the evolution of adsorption characteristics with respect to a broadening pore network can be investigated starting from the narrowest nanopore width. With an increasing mean pore width, a H2-type hysteresis develops gradually which finally transforms into a H1-type. In this connection, a transition from a cavitation-induced desorption toward desorption controlled by pore blocking can be observed. Furthermore, we find concrete hints for a pore size dependence of the relative pressure of cavitation in highly disordered pore systems. By comparing nitrogen and argon adsorption, a comprehensive insight into adsorption mechanisms in novel disordered materials is provided.

  11. Passive cavitation imaging with ultrasound arrays.

    Science.gov (United States)

    Salgaonkar, Vasant A; Datta, Saurabh; Holland, Christy K; Mast, T Douglas

    2009-12-01

    A method is presented for passive imaging of cavitational acoustic emissions using an ultrasound array, with potential application in real-time monitoring of ultrasound ablation. To create such images, microbubble emissions were passively sensed by an imaging array and dynamically focused at multiple depths. In this paper, an analytic expression for a passive image is obtained by solving the Rayleigh-Sommerfield integral, under the Fresnel approximation, and passive images were simulated. A 192-element array was used to create passive images, in real time, from 520-kHz ultrasound scattered by a 1-mm steel wire. Azimuthal positions of this target were accurately estimated from the passive images. Next, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble clusters formed in the saline samples were consistently located on both passive images and B-scans. Passive images were also created using broadband emissions from bovine liver sonicated at 2.2 MHz. Agreement was found between the images and source beam shape, indicating an ability to map therapeutic ultrasound beams in situ. The relation between these broadband emissions, sonication amplitude, and exposure conditions are discussed.

  12. Characterization of the cavitating flow in converging-diverging nozzle based on experimental investigations

    Directory of Open Access Journals (Sweden)

    Rudolf Pavel

    2014-03-01

    Full Text Available Cavitation phenomena occuring in converging-diverging nozzle (Venturi tube are described in the paper. A closed test circuit with possibility to control both flow rate and static pressure level were used. Loss coefficient was evaluated for different sigma numbers resulting in full „static“ characterization of the nozzle. Visualizations of the cavitation pattern development were acquired and matched with evolution of the loss coefficient. Three cavitation regimes are described: partial cavitation, fully developed cavitation, supercavitation.

  13. Experimental evaluation of numerical simulation of cavitating flow around hydrofoil

    Energy Technology Data Exchange (ETDEWEB)

    Dular, M.; Bachert, R.; Stoffel, B. [Darmstadt Univ. of Technology, Lab. for Turbomachinery and Fluid Power (Germany); Sirok, B. [Ljubljana Univ., Lab. for Water and Turbine Machines (Slovenia)

    2005-08-01

    Cavitation in hydraulic machines causes different problems that can be related to its unsteady nature. An experimental and numerical study of developed cavitating flow was performed. Until now simulations of cavitating flow were limited to the self developed 'in house' CFD codes. The goal of the work was to experimentally evaluate the capabilities of a commercial CFD code (Fluent) for simulation of a developed cavitating flow. Two simple hydrofoils that feature some 3D effects of cavitation were used for the experiments. A relatively new technique where PIV method combined with LIF technique was used to experimentally determine the instantaneous and average velocity and void ratio fields (cavity shapes) around the hydrofoils. Distribution of static pressure on the hydrofoil surface was determined. For the numerical simulation of cavitating flow a bubble dynamics cavitation model was used to describe the generation and evaporation of vapour phase. An unsteady RANS 3D simulation was performed. Comparison between numerical and experimental results shows good correlation. The distribution and size of vapour structures and the velocity fields agree well. The distribution of pressure on the hydrofoil surface is correctly predicted. The numerically predicted shedding frequencies are in fair agreement with the experimental data. (authors)

  14. NUMERICAL SIMULATION OF CAVITATION FLOW UNDER HIGH PRESSURE AND TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei-guo; ZHANG Ling-xin; SHAO Xue-ming

    2011-01-01

    The numerical simulation