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Sample records for aided diagnosis cad

  1. Computer-aided-diagnosis (CAD) for colposcopy

    NASA Astrophysics Data System (ADS)

    Lange, Holger; Ferris, Daron G.

    2005-04-01

    Uterine cervical cancer is the second most common cancer among women worldwide. Colposcopy is a diagnostic method, whereby a physician (colposcopist) visually inspects the lower genital tract (cervix, vulva and vagina), with special emphasis on the subjective appearance of metaplastic epithelium comprising the transformation zone on the cervix. Cervical cancer precursor lesions and invasive cancer exhibit certain distinctly abnormal morphologic features. Lesion characteristics such as margin; color or opacity; blood vessel caliber, intercapillary spacing and distribution; and contour are considered by colposcopists to derive a clinical diagnosis. Clinicians and academia have suggested and shown proof of concept that automated image analysis of cervical imagery can be used for cervical cancer screening and diagnosis, having the potential to have a direct impact on improving women"s health care and reducing associated costs. STI Medical Systems is developing a Computer-Aided-Diagnosis (CAD) system for colposcopy -- ColpoCAD. At the heart of ColpoCAD is a complex multi-sensor, multi-data and multi-feature image analysis system. A functional description is presented of the envisioned ColpoCAD system, broken down into: Modality Data Management System, Image Enhancement, Feature Extraction, Reference Database, and Diagnosis and directed Biopsies. The system design and development process of the image analysis system is outlined. The system design provides a modular and open architecture built on feature based processing. The core feature set includes the visual features used by colposcopists. This feature set can be extended to include new features introduced by new instrument technologies, like fluorescence and impedance, and any other plausible feature that can be extracted from the cervical data. Preliminary results of our research on detecting the three most important features: blood vessel structures, acetowhite regions and lesion margins are shown. As this is a new

  2. Computer-aided diagnosis (CAD) for colonoscopy

    NASA Astrophysics Data System (ADS)

    Gu, Jia; Poirson, Allen

    2007-03-01

    Colorectal cancer is the second leading cause of cancer deaths, and ranks third for new cancer cases and cancer mortality for both men and women. However, its death rate can be dramatically reduced by appropriate treatment when early detection is available. The purpose of colonoscopy is to identify and assess the severity of lesions, which may be flat or protruding. Due to the subjective nature of the examination, colonoscopic proficiency is highly variable and dependent upon the colonoscopist's knowledge and experience. An automated image processing system providing an objective, rapid, and inexpensive analysis of video from a standard colonoscope could provide a valuable tool for screening and diagnosis. In this paper, we present the design, functionality and preliminary results of its Computer-Aided-Diagnosis (CAD) system for colonoscopy - ColonoCAD TM. ColonoCAD is a complex multi-sensor, multi-data and multi-algorithm image processing system, incorporating data management and visualization, video quality assessment and enhancement, calibration, multiple view based reconstruction, feature extraction and classification. As this is a new field in medical image processing, our hope is that this paper will provide the framework to encourage and facilitate collaboration and discussion between industry, academia, and medical practitioners.

  3. Can computer-aided diagnosis (CAD) help radiologists find mammographically missed screening cancers?

    NASA Astrophysics Data System (ADS)

    Nishikawa, Robert M.; Giger, Maryellen L.; Schmidt, Robert A.; Papaioannou, John

    2001-06-01

    We present data from a pilot observer study whose goal is design a study to test the hypothesis that computer-aided diagnosis (CAD) can improve radiologists' performance in reading screening mammograms. In a prospective evaluation of our computer detection schemes, we have analyzed over 12,000 clinical exams. Retrospective review of the negative screening mammograms for all cancer cases found an indication of the cancer in 23 of these negative cases. The computer found 54% of these in our prospective testing. We added to these cases normal exams to create a dataset of 75 cases. Four radiologists experienced in mammography read the cases and gave their BI-RADS assessment and their confidence that the patient should be called back for diagnostic mammography. They did so once reading the films only and a second time reading with the computer aid. Three radiologists had no change in area under the ROC curve (mean Az of 0.73) and one improved from 0.73 to 0.78, but this difference failed to reach statistical significance (p equals 0.23). These data are being used to plan a larger more powerful study.

  4. Improvement of MS (multiple sclerosis) CAD (computer aided diagnosis) performance using C/C++ and computing engine in the graphical processing unit (GPU)

    NASA Astrophysics Data System (ADS)

    Suh, Joohyung; Ma, Kevin; Le, Anh

    2011-03-01

    Multiple Sclerosis (MS) is a disease which is caused by damaged myelin around axons of the brain and spinal cord. Currently, MR Imaging is used for diagnosis, but it is very highly variable and time-consuming since the lesion detection and estimation of lesion volume are performed manually. For this reason, we developed a CAD (Computer Aided Diagnosis) system which would assist segmentation of MS to facilitate physician's diagnosis. The MS CAD system utilizes K-NN (k-nearest neighbor) algorithm to detect and segment the lesion volume in an area based on the voxel. The prototype MS CAD system was developed under the MATLAB environment. Currently, the MS CAD system consumes a huge amount of time to process data. In this paper we will present the development of a second version of MS CAD system which has been converted into C/C++ in order to take advantage of the GPU (Graphical Processing Unit) which will provide parallel computation. With the realization of C/C++ and utilizing the GPU, we expect to cut running time drastically. The paper investigates the conversion from MATLAB to C/C++ and the utilization of a high-end GPU for parallel computing of data to improve algorithm performance of MS CAD.

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

    PubMed Central

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

    2016-01-01

    Aims and Objectives: To determine the overall performance of an existing CAD algorithm with thin-section computed tomography (CT) in the detection of pulmonary nodules and to evaluate detection sensitivity at a varying range of nodule density, size, and location. Materials and Methods: A cross-sectional prospective study was conducted on 20 patients with 322 suspected nodules who underwent diagnostic chest imaging using 64-row multi-detector CT. The examinations were evaluated on reconstructed images of 1.4 mm thickness and 0.7 mm interval. Detection of pulmonary nodules, initially by a radiologist of 2 years experience (RAD) and later by CAD lung nodule software was assessed. Then, CAD nodule candidates were accepted or rejected accordingly. Detected nodules were classified based on their size, density, and location. The performance of the RAD and CAD system was compared with the gold standard that is true nodules confirmed by consensus of senior RAD and CAD together. The overall sensitivity and false-positive (FP) rate of CAD software was calculated. Observations and Results: Of the 322 suspected nodules, 221 were classified as true nodules on the consensus of senior RAD and CAD together. Of the true nodules, the RAD detected 206 (93.2%) and 202 (91.4%) by the CAD. CAD and RAD together picked up more number of nodules than either CAD or RAD alone. Overall sensitivity for nodule detection with the CAD program was 91.4%, and FP detection per patient was 5.5%. The CAD showed comparatively higher sensitivity for nodules of size 4–10 mm (93.4%) and nodules in hilar (100%) and central (96.5%) location when compared to RAD's performance. Conclusion: CAD performance was high in detecting pulmonary nodules including the small size and low-density nodules. CAD even with relatively high FP rate, assists and improves RAD's performance as a second reader, especially for nodules located in the central and hilar region and for small nodules by saving RADs time. PMID:27578931

  6. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    NASA Astrophysics Data System (ADS)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-09-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 × 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver ( p < 0.05). Furthermore, the F-value, which was used as a scale for the difference in recognition rates, was highest in the average gray level, relatively high in the skewness and the entropy, and relatively low in the uniformity, the relative smoothness and the average contrast. The recognition rate for a fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  7. New results in computer-aided diagnosis (CAD) of breast cancer using a recently developed SVM/GRNN Oracle hybrid

    NASA Astrophysics Data System (ADS)

    Land, Walker H., Jr.; Wong, Lut; McKee, Daniel W.; Masters, Timothy; Anderson, Frances R.; Raturi, Anurag; Lo, Joseph Y.

    2004-05-01

    Breast cancer is second only to lung cancer as a tumor-related cause of death in women. Currently, the method of choice for the early detection of breast cancer is mammography. While sensitive to the detection of non palpable breast lesions, its positive predictive value (PPV) is low, resulting in biopsies that are only 15%-34% likely to reveal malignancy. This paper explores the use of a recently designed Support Vector Machine (SVM)/Generalized Regression Neural Network (GRNN) Oracle hybrid to classify breast lesions and evaluate the software's performance as an interpretive aid to radiologists. The main objective of the research was to perform an independent analysis, using a new, integrated film screen mammogram data base of approximately 2500 cases from five separate institutions, to verify results obtained previously[14]. This study demonstrated the following: (1) The DE crossover constant has little, if any, effect on measures of performance (MOP). (2) A specificity of approximately 5.6% is achieved at 100% sensitivity, which increases to approximately 36% at 95% sensitivity. (3) PPV increases from 51% to 56% as sensitivity is decreased from 100 to 95%, respectively.

  8. CAD tool for burn diagnosis.

    PubMed

    Acha, Begoña; Serrano, Carmen; Acha, José I; Roa, Laura M

    2003-07-01

    In this paper a new system for burn diagnosis is proposed. The aim of the system is to separate burn wounds from healthy skin, and the different types of burns (burn depths) from each other, identifying each one. The system is based on the colour and texture information, as these are the characteristics observed by physicians in order to give a diagnosis. We use a perceptually uniform colour space (L*u*v*), since Euclidean distances calculated in this space correspond to perceptually colour differences. After the burn is segmented, some colour and texture descriptors are calculated and they are the inputs to a Fuzzy-ARTMAP neural network. The neural network classifies them into three types of bums: superficial dermal, deep dermal and full thickness. Clinical effectiveness of the method was demonstrated on 62 clinical burn wound images obtained from digital colour photographs, yielding an average classification success rate of 82% compared to expert classified images.

  9. CAD tool for burn diagnosis.

    PubMed

    Acha, Begoña; Serrano, Carmen; Acha, José I; Roa, Laura M

    2003-07-01

    In this paper a new system for burn diagnosis is proposed. The aim of the system is to separate burn wounds from healthy skin, and the different types of burns (burn depths) from each other, identifying each one. The system is based on the colour and texture information, as these are the characteristics observed by physicians in order to give a diagnosis. We use a perceptually uniform colour space (L*u*v*), since Euclidean distances calculated in this space correspond to perceptually colour differences. After the burn is segmented, some colour and texture descriptors are calculated and they are the inputs to a Fuzzy-ARTMAP neural network. The neural network classifies them into three types of bums: superficial dermal, deep dermal and full thickness. Clinical effectiveness of the method was demonstrated on 62 clinical burn wound images obtained from digital colour photographs, yielding an average classification success rate of 82% compared to expert classified images. PMID:15344466

  10. Computer-aided diagnosis in thoracic CT

    NASA Astrophysics Data System (ADS)

    Li, Qiang

    2009-10-01

    Computer-aided diagnosis (CAD) provides a computer output as a "second opinion" in order to assist radiologists in the diagnosis of various diseases on medical images. Currently, a hot topic in CAD is the development of computerized schemes for detection of lung abnormalities, such as lung nodule and interstitial lung disease, in computed tomography (CT) images. The author describes in this article the current status of the CAD schemes for the detection of lung nodules and interstitial lung disease in CT developed by the author and his colleagues at the University of Chicago and Duke University.

  11. Role of computer aided detection (CAD) integration: case study with meniscal and articular cartilage CAD applications

    NASA Astrophysics Data System (ADS)

    Safdar, Nabile; Ramakrishna, Bharath; Saiprasad, Ganesh; Siddiqui, Khan; Siegel, Eliot

    2008-03-01

    Knee-related injuries involving the meniscal or articular cartilage are common and require accurate diagnosis and surgical intervention when appropriate. With proper techniques and experience, confidence in detection of meniscal tears and articular cartilage abnormalities can be quite high. However, for radiologists without musculoskeletal training, diagnosis of such abnormalities can be challenging. In this paper, the potential of improving diagnosis through integration of computer-aided detection (CAD) algorithms for automatic detection of meniscal tears and articular cartilage injuries of the knees is studied. An integrated approach in which the results of algorithms evaluating either meniscal tears or articular cartilage injuries provide feedback to each other is believed to improve the diagnostic accuracy of the individual CAD algorithms due to the known association between abnormalities in these distinct anatomic structures. The correlation between meniscal tears and articular cartilage injuries is exploited to improve the final diagnostic results of the individual algorithms. Preliminary results from the integrated application are encouraging and more comprehensive tests are being planned.

  12. Preparing Students for Computer Aided Drafting (CAD). A Conceptual Approach.

    ERIC Educational Resources Information Center

    Putnam, A. R.; Duelm, Brian

    This presentation outlines guidelines for developing and implementing an introductory course in computer-aided drafting (CAD) that is geared toward secondary-level students. The first section of the paper, which deals with content identification and selection, includes lists of mechanical drawing and CAD competencies and a list of rationales for…

  13. PACS-Based Computer-Aided Detection and Diagnosis

    NASA Astrophysics Data System (ADS)

    Huang, H. K. (Bernie); Liu, Brent J.; Le, Anh HongTu; Documet, Jorge

    The ultimate goal of Picture Archiving and Communication System (PACS)-based Computer-Aided Detection and Diagnosis (CAD) is to integrate CAD results into daily clinical practice so that it becomes a second reader to aid the radiologist's diagnosis. Integration of CAD and Hospital Information System (HIS), Radiology Information System (RIS) or PACS requires certain basic ingredients from Health Level 7 (HL7) standard for textual data, Digital Imaging and Communications in Medicine (DICOM) standard for images, and Integrating the Healthcare Enterprise (IHE) workflow profiles in order to comply with the Health Insurance Portability and Accountability Act (HIPAA) requirements to be a healthcare information system. Among the DICOM standards and IHE workflow profiles, DICOM Structured Reporting (DICOM-SR); and IHE Key Image Note (KIN), Simple Image and Numeric Report (SINR) and Post-processing Work Flow (PWF) are utilized in CAD-HIS/RIS/PACS integration. These topics with examples are presented in this chapter.

  14. Computer Aided Detection (CAD) Systems for Mammography and the Use of GRID in Medicine

    NASA Astrophysics Data System (ADS)

    Lauria, Adele

    It is well known that the most effective way to defeat breast cancer is early detection, as surgery and medical therapies are more efficient when the disease is diagnosed at an early stage. The principal diagnostic technique for breast cancer detection is X-ray mammography. Screening programs have been introduced in many European countries to invite women to have periodic radiological breast examinations. In such screenings, radiologists are often required to examine large numbers of mammograms with a double reading, that is, two radiologists examine the images independently and then compare their results. In this way an increment in sensitivity (the rate of correctly identified images with a lesion) of up to 15% is obtained.1,2 In most radiological centres, it is a rarity to find two radiologists to examine each report. In recent years different Computer Aided Detection (CAD) systems have been developed as a support to radiologists working in mammography: one may hope that the "second opinion" provided by CAD might represent a lower cost alternative to improve the diagnosis. At present, four CAD systems have obtained the FDA approval in the USA. † Studies3,4 show an increment in sensitivity when CAD systems are used. Freer and Ulissey in 2001 5 demonstrated that the use of a commercial CAD system (ImageChecker M1000, R2 Technology) increases the number of cancers detected up to 19.5% with little increment in recall rate. Ciatto et al.,5 in a study simulating a double reading with a commercial CAD system (SecondLook‡), showed a moderate increment in sensitivity while reducing specificity (the rate of correctly identified images without a lesion). Notwithstanding these optimistic results, there is an ongoing debate to define the advantages of the use of CAD as second reader: the main limits underlined, e.g., by Nishikawa6 are that retrospective studies are considered much too optimistic and that clinical studies must be performed to demonstrate a statistically

  15. Creation of Anatomically Accurate Computer-Aided Design (CAD) Solid Models from Medical Images

    NASA Technical Reports Server (NTRS)

    Stewart, John E.; Graham, R. Scott; Samareh, Jamshid A.; Oberlander, Eric J.; Broaddus, William C.

    1999-01-01

    Most surgical instrumentation and implants used in the world today are designed with sophisticated Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) software. This software automates the mechanical development of a product from its conceptual design through manufacturing. CAD software also provides a means of manipulating solid models prior to Finite Element Modeling (FEM). Few surgical products are designed in conjunction with accurate CAD models of human anatomy because of the difficulty with which these models are created. We have developed a novel technique that creates anatomically accurate, patient specific CAD solids from medical images in a matter of minutes.

  16. Computer-aided diagnosis in lung nodule assessment.

    PubMed

    Goldin, Jonathan G; Brown, Matthew S; Petkovska, Iva

    2008-05-01

    Computed tomography (CT) imaging is playing an increasingly important role in cancer detection, diagnosis, and lesion characterization, and it is the most sensitive test for lung nodule detection. Interpretation of lung nodules involves characterization and integration of clinical and other imaging information. Advances in lung nodule management using CT require optimization of CT data acquisition, postprocessing tools, and computer-aided diagnosis (CAD). The goal of CAD systems being developed is to both assist radiologists in the more sensitive detection of nodules and noninvasively differentiate benign from malignant lesions; the latter is important given that malignant lesions account for between 1% and 11% of pulmonary nodules. The aim of this review is to summarize the current state of the art regarding CAD techniques for the detection and characterization of solitary pulmonary nodules and their potential applications in the clinical workup of these lesions.

  17. A Multidisciplinary Research Team Approach to Computer-Aided Drafting (CAD) System Selection. Final Report.

    ERIC Educational Resources Information Center

    Franken, Ken; And Others

    A multidisciplinary research team was assembled to review existing computer-aided drafting (CAD) systems for the purpose of enabling staff in the Design Drafting Department at Linn Technical College (Missouri) to select the best system out of the many CAD systems in existence. During the initial stage of the evaluation project, researchers…

  18. A survey on computer aided diagnosis for ocular diseases

    PubMed Central

    2014-01-01

    Background Computer Aided Diagnosis (CAD), which can automate the detection process for ocular diseases, has attracted extensive attention from clinicians and researchers alike. It not only alleviates the burden on the clinicians by providing objective opinion with valuable insights, but also offers early detection and easy access for patients. Method We review ocular CAD methodologies for various data types. For each data type, we investigate the databases and the algorithms to detect different ocular diseases. Their advantages and shortcomings are analyzed and discussed. Result We have studied three types of data (i.e., clinical, genetic and imaging) that have been commonly used in existing methods for CAD. The recent developments in methods used in CAD of ocular diseases (such as Diabetic Retinopathy, Glaucoma, Age-related Macular Degeneration and Pathological Myopia) are investigated and summarized comprehensively. Conclusion While CAD for ocular diseases has shown considerable progress over the past years, the clinical importance of fully automatic CAD systems which are able to embed clinical knowledge and integrate heterogeneous data sources still show great potential for future breakthrough. PMID:25175552

  19. Computer-aided diagnosis of lumbar stenosis conditions

    NASA Astrophysics Data System (ADS)

    Koompairojn, Soontharee; Hua, Kathleen; Hua, Kien A.; Srisomboon, Jintavaree

    2010-03-01

    Computer-aided diagnosis (CAD) systems are indispensable tools for patients' healthcare in modern medicine. Nevertheless, the only fully automatic CAD system available for lumbar stenosis today is for X-ray images. Its performance is limited due to the limitations intrinsic to X-ray images. In this paper, we present a system for magnetic resonance images. It employs a machine learning classification technique to automatically recognize lumbar spine components. Features can then be extracted from these spinal components. Finally, diagnosis is done by applying a Multilayer Perceptron. This classification framework can learn the features of different spinal conditions from the training images. The trained Perceptron can then be applied to diagnose new cases for various spinal conditions. Our experimental studies based on 62 subjects indicate that the proposed system is reliable and significantly better than our older system for X-ray images.

  20. Improved mammographic interpretation of masses using computer-aided diagnosis.

    PubMed

    Leichter, I; Fields, S; Nirel, R; Bamberger, P; Novak, B; Lederman, R; Buchbinder, S

    2000-01-01

    The aim of this study was to evaluate the effectiveness of computerized image enhancement, to investigate criteria for discriminating benign from malignant mammographic findings by computer-aided diagnosis (CAD), and to test the role of quantitative analysis in improving the accuracy of interpretation of mass lesions. Forty sequential mammographically detected mass lesions referred for biopsy were digitized at high resolution for computerized evaluation. A prototype CAD system which included image enhancement algorithms was used for a better visualization of the lesions. Quantitative features which characterize the spiculation were automatically extracted by the CAD system for a user-defined region of interest (ROI). Reference ranges for malignant and benign cases were acquired from data generated by 214 known retrospective cases. The extracted parameters together with the reference ranges were presented to the radiologist for the analysis of 40 prospective cases. A pattern recognition scheme based on discriminant analysis was trained on the 214 retrospective cases, and applied to the prospective cases. Accuracy of interpretation with and without the CAD system, as well as the performance of the pattern recognition scheme, were analyzed using receiver operating characteristics (ROC) curves. A significant difference (p < 0.005) was found between features extracted by the CAD system for benign and malignant cases. Specificity of the CAD-assisted diagnosis improved significantly (p < 0.02) from 14 % for the conventional assessment to 50 %, and the positive predictive value increased from 0.47 to 0.62 (p < 0.04). The area under the ROC curve (A(z)) increased significantly (p < 0. 001) from 0.66 for the conventional assessment to 0.81 for the CAD-assisted analysis. The A(z) for the results of the pattern recognition scheme was higher (0.95). The results indicate that there is an improved accuracy of diagnosis with the use of the mammographic CAD system above that of the

  1. HIV / AIDS: Symptoms, Diagnosis, Prevention and Treatment

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV / AIDS: Symptoms , Diagnosis, Prevention and Treatment Past Issues / ... Most people who have become recently infected with HIV will not have any symptoms. They may, however, ...

  2. Surgical retained foreign object (RFO) prevention by computer aided detection (CAD)

    NASA Astrophysics Data System (ADS)

    Marentis, Theodore C.; Hadjiiyski, Lubomir; Chaudhury, Amrita R.; Rondon, Lucas; Chronis, Nikolaos; Chan, Heang-Ping

    2014-03-01

    Surgical Retained Foreign Objects (RFOs) cause significant morbidity and mortality. They are associated with $1.5 billion annually in preventable medical costs. The detection accuracy of radiographs for RFOs is a mediocre 59%. We address the RFO problem with two complementary technologies: a three dimensional (3D) Gossypiboma Micro Tag (μTa) that improves the visibility of RFOs on radiographs, and a Computer Aided Detection (CAD) system that detects the μTag. The 3D geometry of the μTag produces a similar 2D depiction on radiographs regardless of its orientation in the human body and ensures accurate detection by a radiologist and the CAD. We create a database of cadaveric radiographs with the μTag and other common man-made objects positioned randomly. We develop the CAD modules that include preprocessing, μTag enhancement, labeling, segmentation, feature analysis, classification and detection. The CAD can operate in a high specificity mode for the surgeon to allow for seamless workflow integration and function as a first reader. The CAD can also operate in a high sensitivity mode for the radiologist to ensure accurate detection. On a data set of 346 cadaveric radiographs, the CAD system performed at a high specificity (85.5% sensitivity, 0.02 FPs/image) for the OR and a high sensitivity (96% sensitivity, 0.73 FPs/image) for the radiologists.

  3. An Analysis of Computer Aided Design (CAD) Packages Used at MSFC for the Recent Initiative to Integrate Engineering Activities

    NASA Technical Reports Server (NTRS)

    Smith, Leigh M.; Parker, Nelson C. (Technical Monitor)

    2002-01-01

    This paper analyzes the use of Computer Aided Design (CAD) packages at NASA's Marshall Space Flight Center (MSFC). It examines the effectiveness of recent efforts to standardize CAD practices across MSFC engineering activities. An assessment of the roles played by management, designers, analysts, and manufacturers in this initiative will be explored. Finally, solutions are presented for better integration of CAD across MSFC in the future.

  4. A public image database to support research in computer aided diagnosis.

    PubMed

    Reeves, A P; Biancardi, A M; Yankelevitz, D; Fotin, S; Keller, B M; Jirapatnakul, A; Lee, J

    2009-01-01

    The Public Lung Database to address drug response (PLD) has been developed to support research in computer aided diagnosis (CAD). Originally established for applications involving the characterization of pulmonary nodules, the PLD has been augmented to provide initial datasets for CAD research of other diseases. In general, the best performance for a CAD system is achieved when it is trained with a large amount of well documented data. Such training databases are very expensive to create and their lack of general availability limits the targets that can be considered for CAD applications and hampers development of the CAD field. The approach taken with the PLD has been to make available small datasets together with both manual and automated documentation. Furthermore, datasets with special properties are provided either to span the range of task complexity or to provide small change repeat images for direct calibration and evaluation of CAD systems. This resource offers a starting point for other research groups wishing to pursue CAD research in new directions. It also provides an on-line reference for better defining the issues relating to specific CAD tasks.

  5. Computer-aided diagnosis of alcoholism-related EEG signals.

    PubMed

    Acharya, U Rajendra; S, Vidya; Bhat, Shreya; Adeli, Hojjat; Adeli, Amir

    2014-12-01

    Alcoholism is a severe disorder that affects the functionality of neurons in the central nervous system (CNS) and alters the behavior of the affected person. Electroencephalogram (EEG) signals can be used as a diagnostic tool in the evaluation of subjects with alcoholism. The neurophysiological interpretation of EEG signals in persons with alcoholism (PWA) is based on observation and interpretation of the frequency and power in their EEGs compared to EEG signals from persons without alcoholism. This paper presents a review of the known features of EEGs obtained from PWA and proposes that the impact of alcoholism on the brain can be determined by computer-aided analysis of EEGs through extracting the minute variations in the EEG signals that can differentiate the EEGs of PWA from those of nonaffected persons. The authors advance the idea of automated computer-aided diagnosis (CAD) of alcoholism by employing the EEG signals. This is achieved through judicious combination of signal processing techniques such as wavelet, nonlinear dynamics, and chaos theory and pattern recognition and classification techniques. A CAD system is cost-effective and efficient and can be used as a decision support system by physicians in the diagnosis and treatment of alcoholism especially those who do not specialize in alcoholism or neurophysiology. It can also be of great value to rehabilitation centers to assess PWA over time and to monitor the impact of treatment aimed at minimizing or reversing the effects of the disease on the brain. A CAD system can be used to determine the extent of alcoholism-related changes in EEG signals (low, medium, high) and the effectiveness of therapeutic plans.

  6. A handheld computer-aided diagnosis system and simulated analysis

    NASA Astrophysics Data System (ADS)

    Su, Mingjian; Zhang, Xuejun; Liu, Brent; Su, Kening; Louie, Ryan

    2016-03-01

    This paper describes a Computer Aided Diagnosis (CAD) system based on cellphone and distributed cluster. One of the bottlenecks in building a CAD system for clinical practice is the storage and process of mass pathology samples freely among different devices, and normal pattern matching algorithm on large scale image set is very time consuming. Distributed computation on cluster has demonstrated the ability to relieve this bottleneck. We develop a system enabling the user to compare the mass image to a dataset with feature table by sending datasets to Generic Data Handler Module in Hadoop, where the pattern recognition is undertaken for the detection of skin diseases. A single and combination retrieval algorithm to data pipeline base on Map Reduce framework is used in our system in order to make optimal choice between recognition accuracy and system cost. The profile of lesion area is drawn by doctors manually on the screen, and then uploads this pattern to the server. In our evaluation experiment, an accuracy of 75% diagnosis hit rate is obtained by testing 100 patients with skin illness. Our system has the potential help in building a novel medical image dataset by collecting large amounts of gold standard during medical diagnosis. Once the project is online, the participants are free to join and eventually an abundant sample dataset will soon be gathered enough for learning. These results demonstrate our technology is very promising and expected to be used in clinical practice.

  7. Computer-aided diagnosis of dysplasia in Barrett"s esophagus using endoscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Qi, Xin; Sivak, Michael V., Jr.; Wilson, David L.; Rollins, Andrew M.

    2004-07-01

    Barrett's esophagus (BE) has become a major health care burden because of its association with adenocarcinoma of the esophagus. We have shown that endoscopic optical coherence tomography (EOCT) has a 70% accuracy in the diagnosis of dysplasia (Gastrointest Endosc 2003; 57:AB77). To demonstrate the feasiblity of computer aided diagnosis (CAD) of dysplasia in BE using EOCT digital images, to quantitate/standardize the diagnosis of dysplasia, and to develop algorithms suitable for EOCT surveillance of large areas of Barrett"s mucosa, 106 EOCT images were selected (13 patients from 28 cases) from the clinical study including 68 of non-dysplastic and 38 of dysplastic mucosa. From the digital image stream, the 3 frames immediately preceding impact of the forceps on the tissue were selected to insure close correlation between histology/EOCT image pairs. Computer aided diagnosis by center symmetric autocorrelation (CENS) and principal component analysis (PCA) were used for feature parameter extraction and analysis based on the segmented ROI. Leave-one-out cross-validation was used for classification and finally receiver operating characteristic (ROC) curve was used to evaluate the performance of CAD and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated. The result shows that CAD is able to achieve a higher accuracy than humans for identification of dysplasia in EOCT images. CAD may be of assistance in the EOCT surveillance of large surface areas of Barrett"s mucosa for dysplasia.

  8. Computer aided diagnosis of diabetic peripheral neuropathy

    NASA Astrophysics Data System (ADS)

    Chekh, Viktor; Soliz, Peter; McGrew, Elizabeth; Barriga, Simon; Burge, Mark; Luan, Shuang

    2014-03-01

    Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patients. It most often affects the extremities, such as the feet, and can lead to peripheral vascular disease, deformity, infection, ulceration, and even amputation. The key to managing diabetic foot is prevention and early detection. Unfortunately, current existing diagnostic techniques are mostly based on patient sensations and exhibit significant inter- and intra-observer differences. We have developed a computer aided diagnostic (CAD) system for diabetic peripheral neuropathy. The thermal response of the feet of diabetic patients following cold stimulus is captured using an infrared camera. The plantar foot in the images from a thermal video are segmented and registered for tracking points or specific regions. The temperature recovery of each point on the plantar foot is extracted using our bio-thermal model and analyzed. The regions that exhibit abnormal ability to recover are automatically identified to aid the physicians to recognize problematic areas. The key to our CAD system is the segmentation of infrared video. The main challenges for segmenting infrared video compared to normal digital video are (1) as the foot warms up, it also warms up the surrounding, creating an ever changing contrast; and (2) there may be significant motion during imaging. To overcome this, a hybrid segmentation algorithm was developed based on a number of techniques such as continuous max-flow, model based segmentation, shape preservation, convex hull, and temperature normalization. Verifications of the automatic segmentation and registration using manual segmentation and markers show good agreement.

  9. The Recent Progress in Quantitative Medical Image Analysis for Computer Aided Diagnosis Systems

    PubMed Central

    Kim, Tae-Yun; Son, Jaebum

    2011-01-01

    Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. Many different CAD schemes are being developed for use in the detection and/or characterization of various lesions found through various types of medical imaging. These imaging technologies employ conventional projection radiography, computed tomography, magnetic resonance imaging, ultrasonography, etc. In order to achieve a high performance level for a computerized diagnosis, it is important to employ effective image analysis techniques in the major steps of a CAD scheme. The main objective of this review is to attempt to introduce the diverse methods used for quantitative image analysis, and to provide a guide for clinicians. PMID:22084808

  10. Development and assessment of a clinically viable system for breast ultrasound computer-aided diagnosis

    NASA Astrophysics Data System (ADS)

    Gruszauskas, Nicholas Peter

    The chances of surviving a breast cancer diagnosis as well as the effectiveness of any potential treatments increase significantly with early detection of the disease. As such, a considerable amount of research is being conducted to augment the breast cancer detection and diagnosis process. One such area of research involves the investigation and application of sophisticated computer algorithms to assist clinicians in detecting and diagnosing breast cancer on medical images (termed generally as "computer-aided diagnosis" or CAD). This study investigated a previously-developed breast ultrasound CAD system with the intent of translating it into a clinically-viable system. While past studies have demonstrated that breast ultrasound CAD may be a beneficial aid during the diagnosis of breast cancer on ultrasound, there are no investigations concerning its potential clinical translation and there are currently no commercially-available implementations of such systems. This study "bridges the gap" between the laboratory-developed system and the steps necessary for clinical implementation. A novel observer study was conducted that mimicked the clinical use of the breast ultrasound CAD system in order to assess the impact it had on the diagnostic performance of the user. Several robustness studies were also performed: the sonographic features used by the system were evaluated and the databases used for calibration and testing were characterized, the effect of the user's input was assessed by evaluating the performance of the system with variations in lesion identification and image selection, and the performance of the system on different patient populations was investigated by evaluating its performance on a database consisting solely of patients with Asian ethnicity. The analyses performed here indicate that the breast ultrasound CAD system under investigation is robust and demonstrates only minor variability when subjected to "real-world" use. All of these results are

  11. Computer-aided determination of occlusal contact points for dental 3-D CAD.

    PubMed

    Maruyama, Tomoaki; Nakamura, Yasuo; Hayashi, Toyohiko; Kato, Kazumasa

    2006-05-01

    Present dental CAD systems enable us to design functional occlusal tooth surfaces which harmonize with the patient's stomatognathic function. In order to avoid occlusal interferences during tooth excursions, currently available systems usually use the patient's functional occlusal impressions for the design of occlusal contact points. Previous interfere-free design, however, has been done on a trial-and-error basis by using visual inspection. To improve this time-consuming procedure, this paper proposes a computer-aided system for assisting in the determination of the occlusal contact points by visualizing the appropriate regions of the opposing surface. The system can designate such regions from data of the opposing occlusal surfaces and their relative movements can be simulated by using a virtual articulator. Experiments for designing the crown of a lower first molar demonstrated that all contact points selected within the designated regions completely satisfied the required contact or separation during tooth excursions, confirming the effectiveness of our computer-aided procedure.

  12. Computer-aided diagnosis of breast cancer using cytological images: A systematic review.

    PubMed

    Saha, Monjoy; Mukherjee, Rashmi; Chakraborty, Chandan

    2016-10-01

    Cytological evaluation by microscopic image-based characterization [imprint cytology (IC) and fine needle aspiration cytology (FNAC)] plays an integral role in primary screening/detection of breast cancer. The sensitivity of IC and FNAC as a screening tool is dependent on the image quality and the pathologist's level of expertise. Computer-aided diagnosis (CAD) is used to assists the pathologists by developing various machine learning and image processing algorithms. This study reviews the various manual and computer-aided techniques used so far in breast cytology. Diagnostic applications were studied to estimate the role of CAD in breast cancer diagnosis. This paper presents an overview of image processing and pattern recognition techniques that have been used to address several issues in breast cytology-based CAD including slide preparation, staining, microscopic imaging, pre-processing, segmentation, feature extraction and diagnostic classification. This review provides better insights to readers regarding the state of the art the knowledge on CAD-based breast cancer diagnosis to date. PMID:27528421

  13. Computer-aided diagnosis of breast cancer using cytological images: A systematic review.

    PubMed

    Saha, Monjoy; Mukherjee, Rashmi; Chakraborty, Chandan

    2016-10-01

    Cytological evaluation by microscopic image-based characterization [imprint cytology (IC) and fine needle aspiration cytology (FNAC)] plays an integral role in primary screening/detection of breast cancer. The sensitivity of IC and FNAC as a screening tool is dependent on the image quality and the pathologist's level of expertise. Computer-aided diagnosis (CAD) is used to assists the pathologists by developing various machine learning and image processing algorithms. This study reviews the various manual and computer-aided techniques used so far in breast cytology. Diagnostic applications were studied to estimate the role of CAD in breast cancer diagnosis. This paper presents an overview of image processing and pattern recognition techniques that have been used to address several issues in breast cytology-based CAD including slide preparation, staining, microscopic imaging, pre-processing, segmentation, feature extraction and diagnostic classification. This review provides better insights to readers regarding the state of the art the knowledge on CAD-based breast cancer diagnosis to date.

  14. Computer-aided design and computer-aided manufacture (CAD/CAM) system for construction of spinal orthosis for patients with adolescent idiopathic scoliosis.

    PubMed

    Wong, M S

    2011-01-01

    ABSTRACT Spinal orthoses are commonly prescribed to patients with moderate adolescent idiopathic scoliosis (AIS) for prevention of further curve deterioration. In conventional manufacturing method, plaster bandages are used to obtain the patient's body contour and then the plaster cast is rectified manually. With computer-aided design and computer-aided manufacture (CAD/CAM) system, a series of automated processes from body scanning to digital rectification and milling of the positive model can be performed in a fast and accurate fashion. The purpose of this manuscript is to introduce the application of CAD/CAM system to the construction of spinal orthosis for patients with AIS. Based on evidence within the literature, CAD/CAM method can achieve similar clinical outcomes but with higher efficiency than the conventional fabrication method. Therefore, CAD/CAM method should be considered a substitute to the conventional method in fabrication of spinal orthoses for patients with AIS.

  15. Computer-aided diagnosis in radiological imaging: current status and future challenges

    NASA Astrophysics Data System (ADS)

    Doi, Kunio

    2009-10-01

    Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. Many different types of CAD schemes are being developed for detection and/or characterization of various lesions in medical imaging, including conventional projection radiography, CT, MRI, and ultrasound imaging. Commercial systems for detection of breast lesions on mammograms have been developed and have received FDA approval for clinical use. CAD may be defined as a diagnosis made by a physician who takes into account the computer output as a "second opinion". The purpose of CAD is to improve the quality and productivity of physicians in their interpretation of radiologic images. The quality of their work can be improved in terms of the accuracy and consistency of their radiologic diagnoses. In addition, the productivity of radiologists is expected to be improved by a reduction in the time required for their image readings. The computer output is derived from quantitative analysis of radiologic images by use of various methods and techniques in computer vision, artificial intelligence, and artificial neural networks (ANNs). The computer output may indicate a number of important parameters, for example, the locations of potential lesions such as lung cancer and breast cancer, the likelihood of malignancy of detected lesions, and the likelihood of various diseases based on differential diagnosis in a given image and clinical parameters. In this review article, the basic concept of CAD is first defined, and the current status of CAD research is then described. In addition, the potential of CAD in the future is discussed and predicted.

  16. Computer-aided detection of lung cancer on chest radiographs: effect of machine CAD true positive/false negative detections on radiologists' confidence level

    NASA Astrophysics Data System (ADS)

    Freedman, Matthew T.; Osicka, Teresa; Lo, Shih-Chung Benedict; Lure, Fleming; Xu, Xin-Wei; Lin, Jesse; Zhao, Hui; Zhang, Ron

    2004-05-01

    This paper evaluates the effect of Computer-Aided Detection prompts on the confidence and detection of cancer on chest radiographs. Expected findings included an increase in confidence rating and a decrease in variance in confidence when radiologists interacted with a computer prompt that confirmed their initial decision or induced them to switch from an incorrect to a correct decision. Their confidence rating decreased and the variance of confidence rating increased when the computer failed to confirm a correct or incorrect decision. A population of cases was identified that changed among reading modalities. This unstable group of cases differed between the Independent and Sequential without CAD modalities in cancer detection by radiologists and cancer detection by machine. CAD prompts induced the radiologists to make two types of changes in cases: changes on the sequential modality with CAD that restored an initial diagnosis made in the Independent read and new changes that were not present in the Independent or Sequential reads without CAD. This has implications for double reading of cases. The effects of intra-observer variability and inter-observer variability are suggested as potential causes for differences in statistical significance of the Independent and Sequential Design approaches to ROC studies.

  17. Improving the radiologist-CAD interaction: designing for appropriate trust.

    PubMed

    Jorritsma, W; Cnossen, F; van Ooijen, P M A

    2015-02-01

    Computer-aided diagnosis (CAD) has great potential to improve radiologists' diagnostic performance. However, the reported performance of the radiologist-CAD team is lower than what might be expected based on the performance of the radiologist and the CAD system in isolation. This indicates that the interaction between radiologists and the CAD system is not optimal. An important factor in the interaction between humans and automated aids (such as CAD) is trust. Suboptimal performance of the human-automation team is often caused by an inappropriate level of trust in the automation. In this review, we examine the role of trust in the radiologist-CAD interaction and suggest ways to improve the output of the CAD system so that it allows radiologists to calibrate their trust in the CAD system more effectively. Observer studies of the CAD systems show that radiologists often have an inappropriate level of trust in the CAD system. They sometimes under-trust CAD, thereby reducing its potential benefits, and sometimes over-trust it, leading to diagnostic errors they would not have made without CAD. Based on the literature on trust in human-automation interaction and the results of CAD observer studies, we have identified four ways to improve the output of CAD so that it allows radiologists to form a more appropriate level of trust in CAD. Designing CAD systems for appropriate trust is important and can improve the performance of the radiologist-CAD team. Future CAD research and development should acknowledge the importance of the radiologist-CAD interaction, and specifically the role of trust therein, in order to create the perfect artificial partner for the radiologist. This review focuses on the role of trust in the radiologist-CAD interaction. The aim of the review is to encourage CAD developers to design for appropriate trust and thereby improve the performance of the radiologist-CAD team. PMID:25459198

  18. An Improved CAD System for Breast Cancer Diagnosis Based on Generalized Pseudo-Zernike Moment and Ada-DEWNN Classifier.

    PubMed

    Singh, Satya P; Urooj, Shabana

    2016-04-01

    In this paper, a novel framework of computer-aided diagnosis (CAD) system has been presented for the classification of benign/malignant breast tissues. The properties of the generalized pseudo-Zernike moments (GPZM) and pseudo-Zernike moments (PZM) are utilized as suitable texture descriptors of the suspicious region in the mammogram. An improved classifier- adaptive differential evolution wavelet neural network (Ada-DEWNN) is proposed to improve the classification accuracy of the CAD system. The efficiency of the proposed system is tested on mammograms from the Mammographic Image Analysis Society (mini-MIAS) database using the leave-one-out cross validation as well as on mammograms from the Digital Database for Screening Mammography (DDSM) database using 10-fold cross validation. The proposed method on MIAS-database attains a fair accuracy of 0.8938 and AUC of 0.935 (95 % CI = 0.8213-0.9831). The proposed method is also tested for in-plane rotation and found to be highly rotation invariant. In addition, the proposed classifier is tested and compared with some well-known existing methods using receiver operating characteristic (ROC) analysis using DDSM- database. It is concluded the proposed classifier has better area under the curve (AUC) (0.9289) and highly précised with 95 % CI, 0.8216 to 0.9834 and 0.0384 standard error.

  19. An Improved CAD System for Breast Cancer Diagnosis Based on Generalized Pseudo-Zernike Moment and Ada-DEWNN Classifier.

    PubMed

    Singh, Satya P; Urooj, Shabana

    2016-04-01

    In this paper, a novel framework of computer-aided diagnosis (CAD) system has been presented for the classification of benign/malignant breast tissues. The properties of the generalized pseudo-Zernike moments (GPZM) and pseudo-Zernike moments (PZM) are utilized as suitable texture descriptors of the suspicious region in the mammogram. An improved classifier- adaptive differential evolution wavelet neural network (Ada-DEWNN) is proposed to improve the classification accuracy of the CAD system. The efficiency of the proposed system is tested on mammograms from the Mammographic Image Analysis Society (mini-MIAS) database using the leave-one-out cross validation as well as on mammograms from the Digital Database for Screening Mammography (DDSM) database using 10-fold cross validation. The proposed method on MIAS-database attains a fair accuracy of 0.8938 and AUC of 0.935 (95 % CI = 0.8213-0.9831). The proposed method is also tested for in-plane rotation and found to be highly rotation invariant. In addition, the proposed classifier is tested and compared with some well-known existing methods using receiver operating characteristic (ROC) analysis using DDSM- database. It is concluded the proposed classifier has better area under the curve (AUC) (0.9289) and highly précised with 95 % CI, 0.8216 to 0.9834 and 0.0384 standard error. PMID:26892455

  20. Selection and implementation of a computer aided design and drafting (CAD/D) system

    SciTech Connect

    Davis, J.P.

    1981-01-01

    Faced with very heavy workloads and limited engineering and graphics personnel, Transco opted for a computer-aided design and drafting system that can produce intelligent drawings, which have associated data bases that can be integrated with other graphical and nongraphical data bases to form comprehensive sets of data for construction projects. Because so much time was being spent in all phases of materials and inventory control, Transco decided to integrate materials-management capabilities into the CAD/D system. When a specific item of material is requested on the graphics equipment, the request triggers production of both the drawing and a materials list. Transco plans to extend its computer applications into mapping tasks as well.

  1. Computer-Aided Design/Manufacturing (CAD/M) for high-speed interconnect

    NASA Astrophysics Data System (ADS)

    Santoski, N. F.

    1981-10-01

    The objective of the Computer-Aided Design/Manufacturing (CAD/M) for High-Speed Interconnect Program study was to assess techniques for design, analysis and fabrication of interconnect structures between high-speed logic ICs that are clocked in the 200 MHz to 5 GHz range. Interconnect structure models were investigated and integrated with existing device models. Design rules for interconnects were developed in terms of parameters that can be installed in software that is used for the design, analysis and fabrication of circuits. To implement these design rules in future software development, algorithms and software development techniques were defined. Major emphasis was on Printed Wiring Board and hybrid level circuits as opposed to monolithic chips. Various packaging schemes were considered, including controlled impedance lines in the 50 to 200 ohms range where needed. The design rules developed are generic in nature, in that various architecture classes and device technologies were considered.

  2. Application of infrared thermography in computer aided diagnosis

    NASA Astrophysics Data System (ADS)

    Faust, Oliver; Rajendra Acharya, U.; Ng, E. Y. K.; Hong, Tan Jen; Yu, Wenwei

    2014-09-01

    The invention of thermography, in the 1950s, posed a formidable problem to the research community: What is the relationship between disease and heat radiation captured with Infrared (IR) cameras? The research community responded with a continuous effort to find this crucial relationship. This effort was aided by advances in processing techniques, improved sensitivity and spatial resolution of thermal sensors. However, despite this progress fundamental issues with this imaging modality still remain. The main problem is that the link between disease and heat radiation is complex and in many cases even non-linear. Furthermore, the change in heat radiation as well as the change in radiation pattern, which indicate disease, is minute. On a technical level, this poses high requirements on image capturing and processing. On a more abstract level, these problems lead to inter-observer variability and on an even more abstract level they lead to a lack of trust in this imaging modality. In this review, we adopt the position that these problems can only be solved through a strict application of scientific principles and objective performance assessment. Computing machinery is inherently objective; this helps us to apply scientific principles in a transparent way and to assess the performance results. As a consequence, we aim to promote thermography based Computer-Aided Diagnosis (CAD) systems. Another benefit of CAD systems comes from the fact that the diagnostic accuracy is linked to the capability of the computing machinery and, in general, computers become ever more potent. We predict that a pervasive application of computers and networking technology in medicine will help us to overcome the shortcomings of any single imaging modality and this will pave the way for integrated health care systems which maximize the quality of patient care.

  3. Revision of Electro-Mechanical Drafting Program to Include CAD/D (Computer-Aided Drafting/Design). Final Report.

    ERIC Educational Resources Information Center

    Snyder, Nancy V.

    North Seattle Community College decided to integrate computer-aided design/drafting (CAD/D) into its Electro-Mechanical Drafting Program. This choice necessitated a redefinition of the program through new curriculum and course development. To initiate the project, a new industrial advisory council was formed. Major electronic and recruiting firms…

  4. Comparison between computer-aided diagnosis and radiologists: assessment of pulmonary blood flow on chest radiographs.

    PubMed

    Kido, S; Arisawa, J; Kuriyama, K; Kuroda, C; Nakamura, H

    2000-01-01

    To evaluate the performance of a computer-aided diagnosis (CAD) scheme for estimating increased pulmonary blood flow on chest radiographs, we compared computerized assessment with findings by radiologists. Our CAD scheme extracts selectively linear opacities corresponding to vessels in regions of interest (ROIs) in the right upper and lower lung zones on digitized chest radiographs, and then calculates a radiographic index as a physical measure that reflects the area of the extracted opacities in selected ROIs. As a measure of increased pulmonary blood flow, the upper/lower radiographic index ratio was calculated for each patient. Seven radiologists estimated the degree of increased pulmonary blood flow for the same images of ROI sets presented on a cathode-ray tube monitor in a randomized order. Between the normal-pulmonary capillary wedge pressure (PCWP) group and increased-PCWP groups, there was no significant difference in performance between CAD and radiologists (p = 0.105). However, when the normal and mild PCWP groups were compared, the performance of CAD was superior to that of radiologists (p = 0.001). This study indicates that our CAD scheme is promising for quantitative estimation of increased pulmonary blood flow, especially in mild cases.

  5. Computer-aided diagnosis of peripheral soft tissue masses based on ultrasound imaging.

    PubMed

    Chiou, Hong-Jen; Chen, Chih-Yen; Liu, Tzu-Chiang; Chiou, See-Ying; Wang, Hsin-Kai; Chou, Yi-Hong; Chiang, Huihua Kenny

    2009-07-01

    Medical ultrasound (US) has been widely used for distinguishing benign from malignant peripheral soft tissue tumors. However, diagnosis by US is subjective and depends on the experience of the radiologists. The rarity of peripheral soft tissue tumors can make them easily neglected and this frequently leads to delayed diagnosis, which results in a much higher death rate than with other tumors. In this paper, we developed a computer-aided diagnosis (CAD) system to diagnose peripheral soft tissue masses on US images. We retrospectively evaluated 49 cases of pathologically proven peripheral soft tissue masses (32 benign, 17 malignant). The proposed CAD system includes three main procedures: image pre-processing and region-of-interest (ROI) segmentation, feature extraction and statistics-based discriminant analysis (DA). We developed a depth-normalization factor (DNF) to compensate for the influence of the depth setting on the apparent size of the ROI. After image pre-processing and normalization, five features, namely area (A), boundary transition ratio (T), circularity (C), high intensity spots (H) and uniformity (U), were extracted from the US images. A DA function was then employed to analyze these features. A CAD algorithm was then devised for differentiating benign from malignant masses. The CAD system achieved an accuracy of 87.8%, a sensitivity of 88.2%, a specificity of 87.5%, a positive predictive value (PPV) 78.9% and a negative predictive value (NPV) 93.3%. These results indicate that the CAD system is valuable as a means of providing a second diagnostic opinion when radiologists carry out peripheral soft tissue mass diagnosis.

  6. CAD: Designs on Business.

    ERIC Educational Resources Information Center

    Milburn, Ken

    1988-01-01

    Provides a general review of the field of Computer-Aided Design Software including specific reviews of "Autosketch,""Generic CADD,""Drafix 1 Plus,""FastCAD," and "Autocad Release 9." Brief articles include "Blueprint for Generation,""CAD for Every Department,""Ideas Sketched in Glass,""CAD on the MAC," and "A CAD Package Sampler." (CW)

  7. Computer-aided diagnosis system for lung cancer based on retrospective helical CT image

    NASA Astrophysics Data System (ADS)

    Ukai, Yuji; Niki, Noboru; Satoh, Hitoshi; Eguchi, Kenji; Mori, Kiyoshi; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Kaneko, Masahiro; Moriyama, Noriyuki

    2000-06-01

    In this paper, we present a computer-aided diagnosis (CAD) system for lung cancer to detect nodule candidates at an early stage from the present and the early helical CT screening of the thorax. We developed an algorithm that can compare automatically the slice images of present and early CT scans for the assistance of comparative reading in retrospect. The algorithm consists of the ROI detection and shape analysis based on comparison of each slice image in the present and the early CT scans. The slice images of present and early CT scans are both displayed in parallel and analyzed quantitatively in order to detect the changes in size and intensity affection. We validated the efficiency of this algorithm by application to image data for mass screening of 50 subjects (total: 150 CT scans). The algorithm could compare the slice images correctly in most combinations with respect to physician's point of view. We validated the efficiency of the algorithm which automatically detect lung nodule candidates using CAD system. The system was applied to the helical CT images of 450 subjects. Currently, we are carrying out the clinical field test program using the CAD system. The results of our CAD system have indicated good performance when compared with physician's diagnosis. The experimental results of the algorithm indicate that our CAD system is useful to increase the efficiency of the mass screening process. CT screening of thorax will be performed by using the CAD system as a counterpart to the double reading technique actually used in herical CT screening program, not by using the film display.

  8. Computer-aided diagnosis system for lung cancer based on retrospective helical CT images

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Ukai, Yuji; Niki, Noboru; Eguchi, Kenji; Mori, Kiyoshi; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Kaneko, Masahiro; Moriyama, Noriyuki

    1999-05-01

    In this paper, we present a computer-aided diagnosis (CAD) system for lung cancer to detect nodule candidates at an early stage from the present and the early helical CT screening of the thorax. We developed an algorithm that can compare automatically the slice images of present and early CT scans for the assistance of comparative reading in retrospect. The algorithm consists of the ROI detection and shape analysis based on comparison of each slice image in the present and the early CT scans. The slice images of present and early CT scans are both displayed in parallel and analyzed quantitatively in order to detect the changes in size and intensity affection. We validated the efficiency of this algorithm by application to image data for mass screening of 50 subjects (total: 150 CT scans). The algorithm could compare the slice images correctly in most combinations with respect to physician's point of view. We validated the efficiency of the algorithm which automatically detect lung nodule candidates using CAD system. The system was applied to the helical CT images of 450 subjects. Currently, we are carrying out the clinical field test program using the CAD system. The results of our CAD system have indicated good performance when compared with physician's diagnosis. The experimental results of the algorithm indicate that our CAD system is useful to increase the efficiency of the mass screening process. CT screening of thorax will be performed by using the CAD system as a counterpart to the double reading technique actually used in herical CT screening program, not by using the film display.

  9. Clinical Approach to Diagnosis of Pre-Dementia Alzheimer's Disease (CAD-PAD)

    PubMed Central

    Alom, J.; Llinares, I.; Fajardo, S.

    2012-01-01

    Objective Our aim was to evaluate clinical and neuropsychological features to identify pre-dementia Alzheimer's disease (PAD) among mild cognitive impairment (MCI) patients. Methods A longitudinal prospective study of 89 consecutive patients affected with MCI was conducted. Clinical evaluation consisted of a clinical interview protocol, neuropsychological evaluation, standard laboratory tests, and CT scan. A 6-month clinical check-up was made to determine whether patients remained in MCI, improved or progressed to AD or another dementia. Results At 3-year follow-up, 47% patients developed AD dementia. Seventeen variables were significant and were evaluated by logistic regression analysis to identify the remaining optimal diagnostic criteria: age, gender, repeating comments, difficulties in understanding explanations, time of symptom evolution, history of depression, and word fluency (with animals) were identified with a sensitivity of 100% and a specificity of 93%. A computer application was developed with all these variables which we have named Clinical Approach to Diagnosis of PAD (CAD-PAD). Conclusions These results suggest that CAD-PAD can help in the clinical diagnosis of PAD. PMID:22962557

  10. Assessment of the relationship between lesion segmentation accuracy and computer-aided diagnosis scheme performance

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Pu, Jiantao; Park, Sang Cheol; Zuley, Margarita; Gur, David

    2008-03-01

    In this study we randomly select 250 malignant and 250 benign mass regions as a training dataset. The boundary contours of these regions were manually identified and marked. Twelve image features were computed for each region. An artificial neural network (ANN) was trained as a classifier. To select a specific testing dataset, we applied a topographic multi-layer region growth algorithm to detect boundary contours of 1,903 mass regions in an initial pool of testing regions. All processed regions are sorted based on a size difference ratio between manual and automated segmentation. We selected a testing dataset involving 250 malignant and 250 benign mass regions with larger size difference ratios. Using the area under ROC curve (A Z value) as performance index we investigated the relationship between the accuracy of mass segmentation and the performance of a computer-aided diagnosis (CAD) scheme. CAD performance degrades as the size difference ratio increases. Then, we developed and tested a hybrid region growth algorithm that combined the topographic region growth with an active contour approach. In this hybrid algorithm, the boundary contour detected by the topographic region growth is used as the initial contour of the active contour algorithm. The algorithm iteratively searches for the optimal region boundaries. A CAD likelihood score of the growth region being a true-positive mass is computed in each iteration. The region growth is automatically terminated once the first maximum CAD score is reached. This hybrid region growth algorithm reduces the size difference ratios between two areas segmented automatically and manually to less than +/-15% for all testing regions and the testing A Z value increases to from 0.63 to 0.90. The results indicate that CAD performance heavily depends on the accuracy of mass segmentation. In order to achieve robust CAD performance, reducing lesion segmentation error is important.

  11. Computer-Aided Diagnosis of Different Rotator Cuff Lesions Using Shoulder Musculoskeletal Ultrasound.

    PubMed

    Chang, Ruey-Feng; Lee, Chung-Chien; Lo, Chung-Ming

    2016-09-01

    The lifetime prevalence of shoulder pain approaches 70%, which is mostly attributable to rotator cuff lesions such as inflammation, calcific tendinitis and tears. On clinical examination, shoulder ultrasound is recommended for the detection of lesions. However, there exists inter-operator variability in diagnostic accuracy because of differences in the experience and expertise of operators. In this study, a computer-aided diagnosis (CAD) system was developed to assist ultrasound operators in diagnosing rotator cuff lesions and to improve the practicality of ultrasound examination. The collected cases included 43 cases of inflammation, 30 cases of calcific tendinitis and 26 tears. For each case, the lesion area and texture features were extracted from the entire lesions and combined in a multinomial logistic regression classifier for lesion classification. The proposed CAD achieved an accuracy of 87.9%. The individual accuracy of this CAD system was 88.4% for inflammation, 83.3% for calcific tendinitis and 92.3% for tears. Cohen's k was 0.798. On the basis of its diagnostic performance, clinical use of this CAD technique has promise.

  12. Reducing annotation cost and uncertainty in computer-aided diagnosis through selective iterative classification

    NASA Astrophysics Data System (ADS)

    Riely, Amelia; Sablan, Kyle; Xiaotao, Thomas; Furst, Jacob; Raicu, Daniela

    2015-03-01

    Medical imaging technology has always provided radiologists with the opportunity to view and keep records of anatomy of the patient. With the development of machine learning and intelligent computing, these images can be used to create Computer-Aided Diagnosis (CAD) systems, which can assist radiologists in analyzing image data in various ways to provide better health care to patients. This paper looks at increasing accuracy and reducing cost in creating CAD systems, specifically in predicting the malignancy of lung nodules in the Lung Image Database Consortium (LIDC). Much of the cost in creating an accurate CAD system stems from the need for multiple radiologist diagnoses or annotations of each image, since there is rarely a ground truth diagnosis and even different radiologists' diagnoses of the same nodule often disagree. To resolve this issue, this paper outlines an method of selective iterative classification that predicts lung nodule malignancy by using multiple radiologist diagnoses only for cases that can benefit from them. Our method achieved 81% accuracy while costing only 46% of the method that indiscriminately used all annotations, which achieved a lower accuracy of 70%, while costing more.

  13. Enhanced characterization of solid solitary pulmonary nodules with Bayesian analysis-based computer-aided diagnosis

    PubMed Central

    Perandini, Simone; Soardi, Gian Alberto; Motton, Massimiliano; Augelli, Raffaele; Dallaserra, Chiara; Puntel, Gino; Rossi, Arianna; Sala, Giuseppe; Signorini, Manuel; Spezia, Laura; Zamboni, Federico; Montemezzi, Stefania

    2016-01-01

    The aim of this study was to prospectively assess the accuracy gain of Bayesian analysis-based computer-aided diagnosis (CAD) vs human judgment alone in characterizing solitary pulmonary nodules (SPNs) at computed tomography (CT). The study included 100 randomly selected SPNs with a definitive diagnosis. Nodule features at first and follow-up CT scans as well as clinical data were evaluated individually on a 1 to 5 points risk chart by 7 radiologists, firstly blinded then aware of Bayesian Inference Malignancy Calculator (BIMC) model predictions. Raters’ predictions were evaluated by means of receiver operating characteristic (ROC) curve analysis and decision analysis. Overall ROC area under the curve was 0.758 before and 0.803 after the disclosure of CAD predictions (P = 0.003). A net gain in diagnostic accuracy was found in 6 out of 7 readers. Mean risk class of benign nodules dropped from 2.48 to 2.29, while mean risk class of malignancies rose from 3.66 to 3.92. Awareness of CAD predictions also determined a significant drop on mean indeterminate SPNs (15 vs 23.86 SPNs) and raised the mean number of correct and confident diagnoses (mean 39.57 vs 25.71 SPNs). This study provides evidence supporting the integration of the Bayesian analysis-based BIMC model in SPN characterization.

  14. Enhanced characterization of solid solitary pulmonary nodules with Bayesian analysis-based computer-aided diagnosis

    PubMed Central

    Perandini, Simone; Soardi, Gian Alberto; Motton, Massimiliano; Augelli, Raffaele; Dallaserra, Chiara; Puntel, Gino; Rossi, Arianna; Sala, Giuseppe; Signorini, Manuel; Spezia, Laura; Zamboni, Federico; Montemezzi, Stefania

    2016-01-01

    The aim of this study was to prospectively assess the accuracy gain of Bayesian analysis-based computer-aided diagnosis (CAD) vs human judgment alone in characterizing solitary pulmonary nodules (SPNs) at computed tomography (CT). The study included 100 randomly selected SPNs with a definitive diagnosis. Nodule features at first and follow-up CT scans as well as clinical data were evaluated individually on a 1 to 5 points risk chart by 7 radiologists, firstly blinded then aware of Bayesian Inference Malignancy Calculator (BIMC) model predictions. Raters’ predictions were evaluated by means of receiver operating characteristic (ROC) curve analysis and decision analysis. Overall ROC area under the curve was 0.758 before and 0.803 after the disclosure of CAD predictions (P = 0.003). A net gain in diagnostic accuracy was found in 6 out of 7 readers. Mean risk class of benign nodules dropped from 2.48 to 2.29, while mean risk class of malignancies rose from 3.66 to 3.92. Awareness of CAD predictions also determined a significant drop on mean indeterminate SPNs (15 vs 23.86 SPNs) and raised the mean number of correct and confident diagnoses (mean 39.57 vs 25.71 SPNs). This study provides evidence supporting the integration of the Bayesian analysis-based BIMC model in SPN characterization. PMID:27648166

  15. Enhanced characterization of solid solitary pulmonary nodules with Bayesian analysis-based computer-aided diagnosis.

    PubMed

    Perandini, Simone; Soardi, Gian Alberto; Motton, Massimiliano; Augelli, Raffaele; Dallaserra, Chiara; Puntel, Gino; Rossi, Arianna; Sala, Giuseppe; Signorini, Manuel; Spezia, Laura; Zamboni, Federico; Montemezzi, Stefania

    2016-08-28

    The aim of this study was to prospectively assess the accuracy gain of Bayesian analysis-based computer-aided diagnosis (CAD) vs human judgment alone in characterizing solitary pulmonary nodules (SPNs) at computed tomography (CT). The study included 100 randomly selected SPNs with a definitive diagnosis. Nodule features at first and follow-up CT scans as well as clinical data were evaluated individually on a 1 to 5 points risk chart by 7 radiologists, firstly blinded then aware of Bayesian Inference Malignancy Calculator (BIMC) model predictions. Raters' predictions were evaluated by means of receiver operating characteristic (ROC) curve analysis and decision analysis. Overall ROC area under the curve was 0.758 before and 0.803 after the disclosure of CAD predictions (P = 0.003). A net gain in diagnostic accuracy was found in 6 out of 7 readers. Mean risk class of benign nodules dropped from 2.48 to 2.29, while mean risk class of malignancies rose from 3.66 to 3.92. Awareness of CAD predictions also determined a significant drop on mean indeterminate SPNs (15 vs 23.86 SPNs) and raised the mean number of correct and confident diagnoses (mean 39.57 vs 25.71 SPNs). This study provides evidence supporting the integration of the Bayesian analysis-based BIMC model in SPN characterization. PMID:27648166

  16. Enhanced characterization of solid solitary pulmonary nodules with Bayesian analysis-based computer-aided diagnosis.

    PubMed

    Perandini, Simone; Soardi, Gian Alberto; Motton, Massimiliano; Augelli, Raffaele; Dallaserra, Chiara; Puntel, Gino; Rossi, Arianna; Sala, Giuseppe; Signorini, Manuel; Spezia, Laura; Zamboni, Federico; Montemezzi, Stefania

    2016-08-28

    The aim of this study was to prospectively assess the accuracy gain of Bayesian analysis-based computer-aided diagnosis (CAD) vs human judgment alone in characterizing solitary pulmonary nodules (SPNs) at computed tomography (CT). The study included 100 randomly selected SPNs with a definitive diagnosis. Nodule features at first and follow-up CT scans as well as clinical data were evaluated individually on a 1 to 5 points risk chart by 7 radiologists, firstly blinded then aware of Bayesian Inference Malignancy Calculator (BIMC) model predictions. Raters' predictions were evaluated by means of receiver operating characteristic (ROC) curve analysis and decision analysis. Overall ROC area under the curve was 0.758 before and 0.803 after the disclosure of CAD predictions (P = 0.003). A net gain in diagnostic accuracy was found in 6 out of 7 readers. Mean risk class of benign nodules dropped from 2.48 to 2.29, while mean risk class of malignancies rose from 3.66 to 3.92. Awareness of CAD predictions also determined a significant drop on mean indeterminate SPNs (15 vs 23.86 SPNs) and raised the mean number of correct and confident diagnoses (mean 39.57 vs 25.71 SPNs). This study provides evidence supporting the integration of the Bayesian analysis-based BIMC model in SPN characterization.

  17. Computer-aided diagnosis of breast microcalcifications based on dual-tree complex wavelet transform

    PubMed Central

    2012-01-01

    Background Digital mammography is the most reliable imaging modality for breast carcinoma diagnosis and breast micro-calcifications is regarded as one of the most important signs on imaging diagnosis. In this paper, a computer-aided diagnosis (CAD) system is presented for breast micro-calcifications based on dual-tree complex wavelet transform (DT-CWT) to facilitate radiologists like double reading. Methods Firstly, 25 abnormal ROIs were extracted according to the center and diameter of the lesions manually and 25 normal ROIs were selected randomly. Then micro-calcifications were segmented by combining space and frequency domain techniques. We extracted three texture features based on wavelet (Haar, DB4, DT-CWT) transform. Totally 14 descriptors were introduced to define the characteristics of the suspicious micro-calcifications. Principal Component Analysis (PCA) was used to transform these descriptors to a compact and efficient vector expression. Support Vector Machine (SVM) classifier was used to classify potential micro-calcifications. Finally, we used the receiver operating characteristic (ROC) curve and free-response operating characteristic (FROC) curve to evaluate the performance of the CAD system. Results The results of SVM classifications based on different wavelets shows DT-CWT has a better performance. Compared with other results, DT-CWT method achieved an accuracy of 96% and 100% for the classification of normal and abnormal ROIs, and the classification of benign and malignant micro-calcifications respectively. In FROC analysis, our CAD system for clinical dataset detection achieved a sensitivity of 83.5% at a false positive per image of 1.85. Conclusions Compared with general wavelets, DT-CWT could describe the features more effectively, and our CAD system had a competitive performance. PMID:23253202

  18. Teaching for CAD Expertise

    ERIC Educational Resources Information Center

    Chester, Ivan

    2007-01-01

    CAD (Computer Aided Design) has now become an integral part of Technology Education. The recent introduction of highly sophisticated, low-cost CAD software and CAM hardware capable of running on desktop computers has accelerated this trend. There is now quite widespread introduction of solid modeling CAD software into secondary schools but how…

  19. Computer Aided Diagnosis for Confocal Laser Endomicroscopy in Advanced Colorectal Adenocarcinoma

    PubMed Central

    Ştefănescu, Daniela; Streba, Costin; Cârţână, Elena Tatiana; Săftoiu, Adrian; Gruionu, Gabriel; Gruionu, Lucian Gheorghe

    2016-01-01

    Introduction Confocal laser endomicroscopy (CLE) is becoming a popular method for optical biopsy of digestive mucosa for both diagnostic and therapeutic procedures. Computer aided diagnosis of CLE images, using image processing and fractal analysis can be used to quantify the histological structures in the CLE generated images. The aim of this study is to develop an automatic diagnosis algorithm of colorectal cancer (CRC), based on fractal analysis and neural network modeling of the CLE-generated colon mucosa images. Materials and Methods We retrospectively analyzed a series of 1035 artifact-free endomicroscopy images, obtained during CLE examinations from normal mucosa (356 images) and tumor regions (679 images). The images were processed using a computer aided diagnosis (CAD) medical imaging system in order to obtain an automatic diagnosis. The CAD application includes image reading and processing functions, a module for fractal analysis, grey-level co-occurrence matrix (GLCM) computation module, and a feature identification module based on the Marching Squares and linear interpolation methods. A two-layer neural network was trained to automatically interpret the imaging data and diagnose the pathological samples based on the fractal dimension and the characteristic features of the biological tissues. Results Normal colon mucosa is characterized by regular polyhedral crypt structures whereas malignant colon mucosa is characterized by irregular and interrupted crypts, which can be diagnosed by CAD. For this purpose, seven geometric parameters were defined for each image: fractal dimension, lacunarity, contrast correlation, energy, homogeneity, and feature number. Of the seven parameters only contrast, homogeneity and feature number were significantly different between normal and cancer samples. Next, a two-layer feed forward neural network was used to train and automatically diagnose the malignant samples, based on the seven parameters tested. The neural network

  20. Computer aided diagnosis based on medical image processing and artificial intelligence methods

    NASA Astrophysics Data System (ADS)

    Stoitsis, John; Valavanis, Ioannis; Mougiakakou, Stavroula G.; Golemati, Spyretta; Nikita, Alexandra; Nikita, Konstantina S.

    2006-12-01

    Advances in imaging technology and computer science have greatly enhanced interpretation of medical images, and contributed to early diagnosis. The typical architecture of a Computer Aided Diagnosis (CAD) system includes image pre-processing, definition of region(s) of interest, features extraction and selection, and classification. In this paper, the principles of CAD systems design and development are demonstrated by means of two examples. The first one focuses on the differentiation between symptomatic and asymptomatic carotid atheromatous plaques. For each plaque, a vector of texture and motion features was estimated, which was then reduced to the most robust ones by means of ANalysis of VAriance (ANOVA). Using fuzzy c-means, the features were then clustered into two classes. Clustering performances of 74%, 79%, and 84% were achieved for texture only, motion only, and combinations of texture and motion features, respectively. The second CAD system presented in this paper supports the diagnosis of focal liver lesions and is able to characterize liver tissue from Computed Tomography (CT) images as normal, hepatic cyst, hemangioma, and hepatocellular carcinoma. Five texture feature sets were extracted for each lesion, while a genetic algorithm based feature selection method was applied to identify the most robust features. The selected feature set was fed into an ensemble of neural network classifiers. The achieved classification performance was 100%, 93.75% and 90.63% in the training, validation and testing set, respectively. It is concluded that computerized analysis of medical images in combination with artificial intelligence can be used in clinical practice and may contribute to more efficient diagnosis.

  1. A novel approach to computer-aided diagnosis of mammographic images

    SciTech Connect

    Sari-Sarraf, H.; Gleason, S.S.; Hudson, K.T.; Hubner, K.F.

    1996-08-01

    This is a work-in-progress report of a research endeavor that deals with the design and development of a novel approach to computer-aided diagnosis (CAD) of mammographic images. With the initial emphasis being on the analysis of microcalcifications, the proposed approach defines a synergistic paradigm that utilizes new methodologies together with previously developed techniques. The new paradigm is intended to promote a higher degree of accuracy in CAD of mammograms with an increased overall throughput. The process of accomplishing these goals is initiated by the fractal encoding of the input image, which gives rise to the generation of focus-of-attention regions (FARs), that is, regions that contain anomalies. The primary thrust of this work is to demonstrate that by considering FARs, rather than the entire input image, the performances of the ensuing processes (i.e., segmentation, feature extraction, and classification) are enhanced in terms of accuracy and speed. After presenting the proposed approach to CAD of mammographic images, the paper describes the generation of FARs. Furthermore, an experimental study is included that demonstrates the impact of this front-end procedure on the process of microcalcification segmentation. Specifically, the experimentation reveals a dramatic decrease (increase) in the amount of input data (throughput), as well as a reduction in the number of false detections.

  2. Front-End Data Reduction in Computer-Aided Diagnosis of Mammograms: A Pilot Study

    SciTech Connect

    Gleason, S.S.; Nishikawa, R.M.; Sari-Sarraf, H.

    1999-02-20

    This paper presents the results of a pilot study whose primary objective was to further substantiate the efficacy of front-end data reduction in computer-aided diagnosis (CAD) of mammograms. This concept is realized by a preprocessing module that can be utilized at the front-end of most mammographic CAD systems. Based on fractal encoding, this module takes a mammo-graphic image as its input and generates, as its output, a collection of subregions called focus-of-attention regions (FARs). These FARs contain all structures in the input image that appear to be different from the normal background tissue. Subsequently, the CAD systems need only to process the presented FARs, rather than the entire input image. This accomplishes two objectives simultaneously: (1) an increase in throughput via a reduction in the input data, and (2) a reduction in false detections by limiting the scope of the detection algorithms to FARs only. The pilot study consisted of using the preprocessing module to analyze 80 mammographic images. The results were an average data reduction of 83% over all 80 images and an average false detection reduction of 86%. Furthermore, out of a total of 507 marked microcalcifications, 467 fell within FW, representing a coverage rate of 92%.

  3. A ROC-based feature selection method for computer-aided detection and diagnosis

    NASA Astrophysics Data System (ADS)

    Wang, Songyuan; Zhang, Guopeng; Liao, Qimei; Zhang, Junying; Jiao, Chun; Lu, Hongbing

    2014-03-01

    Image-based computer-aided detection and diagnosis (CAD) has been a very active research topic aiming to assist physicians to detect lesions and distinguish them from benign to malignant. However, the datasets fed into a classifier usually suffer from small number of samples, as well as significantly less samples available in one class (have a disease) than the other, resulting in the classifier's suboptimal performance. How to identifying the most characterizing features of the observed data for lesion detection is critical to improve the sensitivity and minimize false positives of a CAD system. In this study, we propose a novel feature selection method mR-FAST that combines the minimal-redundancymaximal relevance (mRMR) framework with a selection metric FAST (feature assessment by sliding thresholds) based on the area under a ROC curve (AUC) generated on optimal simple linear discriminants. With three feature datasets extracted from CAD systems for colon polyps and bladder cancer, we show that the space of candidate features selected by mR-FAST is more characterizing for lesion detection with higher AUC, enabling to find a compact subset of superior features at low cost.

  4. CAD/CAM (Computer Aided Design/Computer Aided Manufacture). A Brief Guide to Materials in the Library of Congress.

    ERIC Educational Resources Information Center

    Havas, George D.

    This brief guide to materials in the Library of Congress (LC) on computer aided design and/or computer aided manufacturing lists reference materials and other information sources under 13 headings: (1) brief introductions; (2) LC subject headings used for such materials; (3) textbooks; (4) additional titles; (5) glossaries and handbooks; (6)…

  5. Informatics infrastructure of CAD system.

    PubMed

    Pietka, Ewa; Gertych, Arkadiusz; Witko, Krzysztof

    2005-01-01

    A computer aided diagnosis (CAD) system requires several components which influence its effectiveness. An image processing methodology is responsible for the analysis, database structure archives and distributes the patient demographics, clinical information, and image data. A graphical user interface is applied in order to enter the data and present it to the user. By designing dynamic Web pages a remote access to the entire is granted. The computer aided diagnosis system includes three layers, which might be installed on various platforms. Elements of the application software are designed independently. Integration of all components is another issue discussed in the presented paper. Implementation of a computer aided diagnosis system improves and accelerates the analysis by giving to the user objective measurement tools. It also standardizes the decision-making process and solves the problem of replicability. Finally, it permits a set of images and features to be collected and recognized as a medical standard and be applied in education and research. PMID:15755535

  6. Computer-aided diagnosis and lipidomics analysis to detect and treat breast cancer

    NASA Astrophysics Data System (ADS)

    Meyer-Bäse, Anke; Retter, Felix; Steinbrücker, Frank; Görke, Robert; Burgeth, Bernhard; Schlossbauer, Thomas

    2010-04-01

    Multi-modality diagnosis techniques are more and more replacing traditional medical imaging for breast cancer detection. Newly emerging advances in both intelligent cancer detection systems and lipidomics technologies offer an excellent opportunity to detect tumors and to understand regulation at the molecular level in many diseases such as cancer. In this paper, we present a detailed computer-aided diagnosis (CAD) systems combining motion artefact reduction and automated feature extraction and classification, and a novel data mining approach for visualization of gene therapy leading to apoptosis in U87 MG glioblastoma cells, a secondary tumor of breast cancer. The achieved results show that the CAD system represents a robust and integrative tool for reliable small contrast enhancing lesions. Graph-clustering methods are introduced as powerful correlation networks which enable a simultaneous exploration and visualization of co-regulation in glioblastoma data. These new paradigms are providing unique "fingerprints" by revealing how the intricate interactions at the lipidome level can be employed to induce apoptosis (cell death) and are thus opening a new window to biomedical frontiers.

  7. Computer-aided diagnosis of pulmonary diseases using x-ray darkfield radiography

    NASA Astrophysics Data System (ADS)

    Einarsdóttir, Hildur; Yaroshenko, Andre; Velroyen, Astrid; Bech, Martin; Hellbach, Katharina; Auweter, Sigrid; Yildirim, Önder; Meinel, Felix G.; Eickelberg, Oliver; Reiser, Maximilian; Larsen, Rasmus; Kjær Ersbøll, Bjarne; Pfeiffer, Franz

    2015-12-01

    In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually annotated to build an experimental dataset. System performance was assessed by: (i) determining the quality of the segmentations; (ii) validating emphysema and fibrosis recognition by a linear support vector machine using leave-one-out cross-validation. In terms of segmentation quality, we obtained an overlap percentage (Ω) 92.63  ±  3.65%, Dice Similarity Coefficient (DSC) 89.74  ±  8.84% and Jaccard Similarity Coefficient 82.39  ±  12.62%. For classification, the accuracy, sensitivity and specificity of diseased lung recognition was 100%. Classification between emphysema and fibrosis resulted in an accuracy of 93%, whilst the sensitivity was 94% and specificity 88%. In addition to the automatic classification of lungs, deviation maps created by the CAD scheme provide a visual aid for medical experts to further assess the severity of pulmonary disease in the lung, and highlights regions affected.

  8. Catheter detection and classification on chest radiographs: an automated prototype computer-aided detection (CAD) system for radiologists

    NASA Astrophysics Data System (ADS)

    Ramakrishna, Bharath; Brown, Matthew; Goldin, Jonathan; Cagnon, Chris; Enzmann, Dieter

    2011-03-01

    Chest radiographs are the quickest and safest method to check placement of man-made medical devices placed in the body like catheters, stents and pacemakers etc out of which catheters are the most commonly used devices. The two most often used catheters especially in the ICU are the Endotracheal (ET) tube used to maintain patient's airway and the Nasogastric (NG) tube used to feed and administer drugs. Tertiary ICU's typically generate over 250 chest radiographs per day to confirm tube placement. Incorrect tube placements can cause serious complications and can even be fatal. The task of identifying these tubes on chest radiographs is difficult for radiologists and ICU personnel given the high volume of cases. This motivates the need for an automatic detection system to aid radiologists in processing these critical cases in a timely fashion while maintaining patient safety. To-date there has been very little research in this area. This paper develops a new fully automatic prototype computer-aided detection (CAD) system for detection and classification of catheters on chest radiographs using a combination of template matching, morphological processing and region growing. The preliminary evaluation was carried out on 25 cases. The prototype CAD system was able to detect ET and NG tubes with sensitivities of 73.7% and 76.5% respectively and with specificities of 91.3% and 84.0% respectively. The results from the prototype system show that it is feasible to automatically detect both catheters on chest radiographs, with the potential to significantly speed the delivery of imaging services while maintaining high accuracy.

  9. Computer-aided diagnosis based on quantitative elastographic features with supersonic shear wave imaging.

    PubMed

    Xiao, Yang; Zeng, Jie; Niu, Lili; Zeng, Qingjing; Wu, Tao; Wang, Congzhi; Zheng, Rongqin; Zheng, Hairong

    2014-02-01

    Supersonic shear wave imaging (SSI) has recently been explored as a technique to evaluate tissue elasticity modulus and has become a valuable tool for tumor characterization. The purpose of this study was to develop a novel computer-aided diagnosis (CAD) system that can acquire quantitative elastographic information from color SSI elastography images automatically and objectively for the purpose of classifying benign and malignant breast tumors. Conventional ultrasonography (US) and SSI elastography images of 125 breast tumors (81 benign, 44 malignant), in 93 consecutive patients (mean age: 40 y, age range: 16-75 y), were obtained. After reconstruction of tissue elasticity data and automatic segmentation of each breast tumor, 10 quantitative elastographic features of the tumor and peri-tumoral areas, respectively (elasticity modulus mean, maximum and standard deviation, hardness degree and elasticity ratio), were computed and evaluated. A support vector machine (SVM) classifier was used for optimum classification via combination of these features. The B-mode Breast Imaging Reporting and Data System (BI-RADS) was used to compare gray-scale US and SSI elastography with respect to diagnostic performance. Histopathologic examination was used as the reference standard. Student's t-test, the Mann-Whitney U-test, the point biserial correlation coefficient and receiver operating characteristic curve analysis were performed for statistical analysis. As a result, the accuracy, sensitivity, specificity, positive predictive value and negative predictive value of benign/malignant classification were 95.2% (119/125), 90.9% (40/44), 97.5% (79/81), 95.2% (40/42) and 95.2% (79/83) for the CAD scheme, respectively, and 79.2% (99/125), 90.9% (40/44), 72.8% (59/81), 64.5% (40/62) and 93.7% (59/63) for BI-RADS assessment, respectively. The area under the receiver operating characteristic curve (Az value) for the proposed CAD system using the combination of elastographic features was

  10. Using the Continuum of Design Modelling Techniques to Aid the Development of CAD Modeling Skills in First Year Industrial Design Students

    ERIC Educational Resources Information Center

    Storer, I. J.; Campbell, R. I.

    2012-01-01

    Industrial Designers need to understand and command a number of modelling techniques to communicate their ideas to themselves and others. Verbal explanations, sketches, engineering drawings, computer aided design (CAD) models and physical prototypes are the most commonly used communication techniques. Within design, unlike some disciplines,…

  11. Role of Gist and PHOG Features in Computer-Aided Diagnosis of Tuberculosis without Segmentation

    PubMed Central

    Chauhan, Arun; Chauhan, Devesh; Rout, Chittaranjan

    2014-01-01

    Purpose Effective diagnosis of tuberculosis (TB) relies on accurate interpretation of radiological patterns found in a chest radiograph (CXR). Lack of skilled radiologists and other resources, especially in developing countries, hinders its efficient diagnosis. Computer-aided diagnosis (CAD) methods provide second opinion to the radiologists for their findings and thereby assist in better diagnosis of cancer and other diseases including TB. However, existing CAD methods for TB are based on the extraction of textural features from manually or semi-automatically segmented CXRs. These methods are prone to errors and cannot be implemented in X-ray machines for automated classification. Methods Gabor, Gist, histogram of oriented gradients (HOG), and pyramid histogram of oriented gradients (PHOG) features extracted from the whole image can be implemented into existing X-ray machines to discriminate between TB and non-TB CXRs in an automated manner. Localized features were extracted for the above methods using various parameters, such as frequency range, blocks and region of interest. The performance of these features was evaluated against textural features. Two digital CXR image datasets (8-bit DA and 14-bit DB) were used for evaluating the performance of these features. Results Gist (accuracy 94.2% for DA, 86.0% for DB) and PHOG (accuracy 92.3% for DA, 92.0% for DB) features provided better results for both the datasets. These features were implemented to develop a MATLAB toolbox, TB-Xpredict, which is freely available for academic use at http://sourceforge.net/projects/tbxpredict/. This toolbox provides both automated training and prediction modules and does not require expertise in image processing for operation. Conclusion Since the features used in TB-Xpredict do not require segmentation, the toolbox can easily be implemented in X-ray machines. This toolbox can effectively be used for the mass screening of TB in high-burden areas with improved efficiency. PMID

  12. Computer-aided diagnosis of carotid atherosclerosis based on ultrasound image statistics, laws' texture and neural networks.

    PubMed

    Mougiakakou, Stavroula G R; Golemati, Spyretta; Gousias, Ioannis; Nicolaides, Andrew N; Nikita, Konstantina S

    2007-01-01

    Quantitative characterisation of carotid atherosclerosis and classification into symptomatic or asymptomatic is crucial in planning optimal treatment of atheromatous plaque. The computer-aided diagnosis (CAD) system described in this paper can analyse ultrasound (US) images of carotid artery and classify them into symptomatic or asymptomatic based on their echogenicity characteristics. The CAD system consists of three modules: a) the feature extraction module, where first-order statistical (FOS) features and Laws' texture energy can be estimated, b) the dimensionality reduction module, where the number of features can be reduced using analysis of variance (ANOVA), and c) the classifier module consisting of a neural network (NN) trained by a novel hybrid method based on genetic algorithms (GAs) along with the back propagation algorithm. The hybrid method is able to select the most robust features, to adjust automatically the NN architecture and to optimise the classification performance. The performance is measured by the accuracy, sensitivity, specificity and the area under the receiver-operating characteristic (ROC) curve. The CAD design and development is based on images from 54 symptomatic and 54 asymptomatic plaques. This study demonstrates the ability of a CAD system based on US image analysis and a hybrid trained NN to identify atheromatous plaques at high risk of stroke.

  13. Gathering Empirical Evidence Concerning Links between Computer Aided Design (CAD) and Creativity

    ERIC Educational Resources Information Center

    Musta'amal, Aede Hatib; Norman, Eddie; Hodgson, Tony

    2009-01-01

    Discussion is often reported concerning potential links between computer-aided designing and creativity, but there is a lack of systematic enquiry to gather empirical evidence concerning such links. This paper reports an indication of findings from other research studies carried out in contexts beyond general education that have sought evidence…

  14. Life Quality Changes after HIV/AIDS Diagnosis: Positive Directions.

    ERIC Educational Resources Information Center

    Soule, Christine J.; Appleton, Valerie

    Diagnosis of HIV/AIDS promotes a fear of the unknown, of death, or annihilation of self, of being, and of identity. Individuals face this threat in unique and holistic ways. This experience of crisis reflects stages of shock, disorganization, reorganization and resolution. Crisis can become a turning point and result in a passage toward successful…

  15. Comparison of standard and double reading and computer-aided detection (CAD) of interval cancers at prior negative screening mammograms: blind review.

    PubMed

    Ciatto, S; Rosselli Del Turco, M; Burke, P; Visioli, C; Paci, E; Zappa, M

    2003-11-01

    The study evaluates the role of computer-aided detection (CAD) in improving the detection of interval cancers as compared to conventional single (CONV) or double reading (DOUBLE). With this purpose, a set of 89 negative cases was seeded with 31 mammograms reported as negative and developing interval cancer in the following 2-year interval (false negative (FN)=11, minimal signs (MS)=20). A total of radiologists read the set with CONV and then with CAD. Overall, there were 589 cancer and 1691 noncancer readings with both CONV and CAD. Double reading was simulated by combining conventional readings in all 171 possible combinations of 19 radiologists, resulting in a total of 5301 cancer and 15 219 noncancer readings. Conventional single, DOUBLE and CAD readings were compared in terms of sensitivity and recall rate. Considering all 19 readings, cancer was identified in 190 or 248 of 589 readings (32.2 vs 42.1%, chi(2)=11.80, df=1, P<0.01) and recalls were 287 or 405 of 1691 readings (16.9 vs 23.9%, chi(2)=24.87, df=1, P<0.01) at CONV or CAD, respectively. When considering FN and MS cases separately, sensitivity at CONV or CAD was 50.2 or 62.6% (chi(2)=6.98, df=1, P=0.01) for FN and 22.3 or 30.7% (chi(2)=6.47, df=1, P=0.01) for MS cases, respectively. Computer-aided detection (average of 19 readings) was slightly and not significantly less sensitive (sensitivity: 42.1 vs 46.1%, chi(2)=3.24, df=1, P=0.07) but more specific (recall rate 23.9 vs 26.1%, chi(2)=3.8, df=1, P=0.04) as compared to DOUBLE (average of 171 readings). Average sensitivity for FN cases only was 62.6% for CAD and 64.8% for DOUBLE (chi(2)=0.32, df=1, P=0.58). Corresponding values for MS cases were 30.7% for CAD and 35.7% for DOUBLE (chi(2)=3.53, df=1, P=0.06). Compared to CONV, CAD allowed for improved sensitivity, though with reduced specificity, both effects being statistically significant. Computer-aided detection was almost as sensitive as DOUBLE but significantly more specific. Computer-aided

  16. Development of problem-oriented software packages for numerical studies and computer-aided design (CAD) of gyrotrons

    NASA Astrophysics Data System (ADS)

    Damyanova, M.; Sabchevski, S.; Zhelyazkov, I.; Vasileva, E.; Balabanova, E.; Dankov, P.; Malinov, P.

    2016-03-01

    Gyrotrons are the most powerful sources of coherent CW (continuous wave) radiation in the frequency range situated between the long-wavelength edge of the infrared light (far-infrared region) and the microwaves, i.e., in the region of the electromagnetic spectrum which is usually called the THz-gap (or T-gap), since the output power of other devices (e.g., solid-state oscillators) operating in this interval is by several orders of magnitude lower. In the recent years, the unique capabilities of the sub-THz and THz gyrotrons have opened the road to many novel and future prospective applications in various physical studies and advanced high-power terahertz technologies. In this paper, we present the current status and functionality of the problem-oriented software packages (most notably GYROSIM and GYREOSS) used for numerical studies, computer-aided design (CAD) and optimization of gyrotrons for diverse applications. They consist of a hierarchy of codes specialized to modelling and simulation of different subsystems of the gyrotrons (EOS, resonant cavity, etc.) and are based on adequate physical models, efficient numerical methods and algorithms.

  17. Clinical experience with a computer-aided diagnosis system for automatic detection of pulmonary nodules at spiral CT of the chest

    NASA Astrophysics Data System (ADS)

    Wormanns, Dag; Fiebich, Martin; Saidi, Mustafa; Diederich, Stefan; Heindel, Walter

    2001-05-01

    The purpose of the study was to evaluate a computer aided diagnosis (CAD) workstation with automatic detection of pulmonary nodules at low-dose spiral CT in a clinical setting for early detection of lung cancer. Two radiologists in consensus reported 88 consecutive spiral CT examinations. All examinations were reviewed using a UNIX-based CAD workstation with a self-developed algorithm for automatic detection of pulmonary nodules. The algorithm was designed to detect nodules with at least 5 mm diameter. The results of automatic nodule detection were compared to the consensus reporting of two radiologists as gold standard. Additional CAD findings were regarded as nodules initially missed by the radiologists or as false positive results. A total of 153 nodules were detected with all modalities (diameter: 85 nodules <5mm, 63 nodules 5-9 mm, 5 nodules >= 10 mm). Reasons for failure of automatic nodule detection were assessed. Sensitivity of radiologists for nodules >=5 mm was 85%, sensitivity of CAD was 38%. For nodules >=5 mm without pleural contact sensitivity was 84% for radiologists at 45% for CAD. CAD detected 15 (10%) nodules not mentioned in the radiologist's report but representing real nodules, among them 10 (15%) nodules with a diameter $GREW5 mm. Reasons for nodules missed by CAD include: exclusion because of morphological features during region analysis (33%), nodule density below the detection threshold (26%), pleural contact (33%), segmentation errors (5%) and other reasons (2%). CAD improves detection of pulmonary nodules at spiral CT significantly and is a valuable second opinion in a clinical setting for lung cancer screening. Optimization of region analysis and an appropriate density threshold have a potential for further improvement of automatic nodule detection.

  18. Age-based computer-aided diagnosis approach for pancreatic cancer on endoscopic ultrasound images

    PubMed Central

    Ozkan, Murat; Cakiroglu, Murat; Kocaman, Orhan; Kurt, Mevlut; Yilmaz, Bulent; Can, Guray; Korkmaz, Ugur; Dandil, Emre; Eksi, Ziya

    2016-01-01

    Aim: The aim was to develop a high-performance computer-aided diagnosis (CAD) system with image processing and pattern recognition in diagnosing pancreatic cancer by using endosonography images. Materials and Methods: On the images, regions of interest (ROI) of three groups of patients (<40, 40-60 and >60) were extracted by experts; features were obtained from images using three different techniques and were trained separately for each age group with an Artificial Neural Network (ANN) to diagnose cancer. The study was conducted on endosonography images of 202 patients with pancreatic cancer and 130 noncancer patients. Results: 122 features were identified from the 332 endosonography images obtained in the study, and the 20 most appropriate features were selected by using the relief method. Images classified under three age groups (in years; <40, 40-60 and >60) were tested via 200 random tests and the following ratios were obtained in the classification: accuracy: 92%, 88.5%, and 91.7%, respectively; sensitivity: 87.5%, 85.7%, and 93.3%, respectively; and specificity: 94.1%, 91.7%, and 88.9%, respectively. When all the age groups were assessed together, the following values were obtained: accuracy: 87.5%, sensitivity: 83.3%, and specificity: 93.3%. Conclusions: It was observed that the CAD system developed in the study performed better in diagnosing pancreatic cancer images based on classification by patient age compared to diagnosis without classification. Therefore, it is imperative to take patient age into consideration to ensure higher performance. PMID:27080608

  19. CAD/CAE Integration Enhanced by New CAD Services Standard

    NASA Technical Reports Server (NTRS)

    Claus, Russell W.

    2002-01-01

    A Government-industry team led by the NASA Glenn Research Center has developed a computer interface standard for accessing data from computer-aided design (CAD) systems. The Object Management Group, an international computer standards organization, has adopted this CAD services standard. The new standard allows software (e.g., computer-aided engineering (CAE) and computer-aided manufacturing software to access multiple CAD systems through one programming interface. The interface is built on top of a distributed computing system called the Common Object Request Broker Architecture (CORBA). CORBA allows the CAD services software to operate in a distributed, heterogeneous computing environment.

  20. A CAD System for Hemorrhagic Stroke.

    PubMed

    Nowinski, Wieslaw L; Qian, Guoyu; Hanley, Daniel F

    2014-09-01

    Computer-aided detection/diagnosis (CAD) is a key component of routine clinical practice, increasingly used for detection, interpretation, quantification and decision support. Despite a critical need, there is no clinically accepted CAD system for stroke yet. Here we introduce a CAD system for hemorrhagic stroke. This CAD system segments, quantifies, and displays hematoma in 2D/3D, and supports evacuation of hemorrhage by thrombolytic treatment monitoring progression and quantifying clot removal. It supports seven-step workflow: select patient, add a new study, process patient's scans, show segmentation results, plot hematoma volumes, show 3D synchronized time series hematomas, and generate report. The system architecture contains four components: library, tools, application with user interface, and hematoma segmentation algorithm. The tools include a contour editor, 3D surface modeler, 3D volume measure, histogramming, hematoma volume plot, and 3D synchronized time-series hematoma display. The CAD system has been designed and implemented in C++. It has also been employed in the CLEAR and MISTIE phase-III, multicenter clinical trials. This stroke CAD system is potentially useful in research and clinical applications, particularly for clinical trials.

  1. Improvements in computer-aided detection/computer-aided classification (CAD/CAC) of bottom mines through post analysis of a diverse set of very shallow water (VSW) environmental test data

    NASA Astrophysics Data System (ADS)

    Ciany, Charles M.; Zurawski, William C.

    2004-09-01

    In 1999 Raytheon adapted its shallow-water Side-Looking Sonar (SLS) Computer Aided Detection/Computer Aided Classification (CAD/CAC) algorithm to process side-scan sonar data obtained with the Woods Hole Oceanographic Institute's Remote Environmental Monitoring Units (REMUS) autonomous underwater vehicle (AUV). To date, Raytheon has demonstrated the ability to effectively execute mine-hunting missions with the REMUS vehicle through the fusion of its CAD/CAC algorithm with several other CAD/CAC algorithms to achieve low false alarm rates while maintaining a high probability of correct detection/classification. Mine-hunting in the very shallow water (VSW) environment poses a host of difficulties including such issues as: a higher incidence of man made clutter, significant interference due to biological sources (such as kelp or silt), the scouring of mines into the bottom, interference from surface/bottom bounce, and image distortion due to vehicle motion during image generation. These issues coupled with highly variable bottom conditions and small bottom targets make reliable hunting in the VSW environment very difficult. In order to be operationally viable, the individual CAD/CAC algorithms must demonstrate robustness over these very different mine-hunting environments. A higher normalized false alarm rate per algorithm is considered acceptable based on the false alarm reduction achieved through multi-algorithm fusion. Raytheon's recent CAD/CAC algorithm enhancements demonstrate a significant improvement in overall CAD/CAC performance across a diverse set of environments, from the relatively benign Gulf of Mexico environment to the more challenging areas off the coast of southern California containing significant biological and bottom clutter. The improvements are attributed to incorporating an image normalizer into the algorithm's pre-processing stage in conjunction with several other modifications. The algorithm enhancements resulted in an 11% increase in overall

  2. Evaluation of Five Microcomputer CAD Packages.

    ERIC Educational Resources Information Center

    Leach, James A.

    1987-01-01

    Discusses the similarities, differences, advanced features, applications and number of users of five microcomputer computer-aided design (CAD) packages. Included are: "AutoCAD (V.2.17)"; "CADKEY (V.2.0)"; "CADVANCE (V.1.0)"; "Super MicroCAD"; and "VersaCAD Advanced (V.4.00)." Describes the evaluation of the packages and makes recommendations for…

  3. The polar phase response property of monopolar ECG voltages using a Computer-Aided Design and Drafting (CAD)-based data acquisition system.

    PubMed

    Goswami, B; Mitra, M; Nag, B; Mitra, T K

    1993-11-01

    The present paper discusses a Computer-Aided Design and Drafting (CAD) based data acquisition and polar phase response study of the ECG. The scalar ECG does not show vector properties although such properties are embedded in it. In the present paper the polar phase response property of monopolar chest lead (V1 to V6) ECG voltages has been studied. A software tool has been used to evaluate the relative phase response of ECG voltages. The data acquisition of monopolar ECG records of chest leads V1 to V6 from the chart recorder has been done with the help of the AutoCAD application package. The spin harmonic constituents of ECG voltages are evaluated at each harmonic plane and the polar phase responses are studied at each plane. Some interesting results have been observed in some typical cases which are discussed in the paper. PMID:8307653

  4. Ultrasound based computer-aided-diagnosis of kidneys for pediatric hydronephrosis

    NASA Astrophysics Data System (ADS)

    Cerrolaza, Juan J.; Peters, Craig A.; Martin, Aaron D.; Myers, Emmarie; Safdar, Nabile; Linguraru, Marius G.

    2014-03-01

    Ultrasound is the mainstay of imaging for pediatric hydronephrosis, though its potential as diagnostic tool is limited by its subjective assessment, and lack of correlation with renal function. Therefore, all cases showing signs of hydronephrosis undergo further invasive studies, like diuretic renogram, in order to assess the actual renal function. Under the hypothesis that renal morphology is correlated with renal function, a new ultrasound based computer-aided diagnosis (CAD) tool for pediatric hydronephrosis is presented. From 2D ultrasound, a novel set of morphological features of the renal collecting systems and the parenchyma, is automatically extracted using image analysis techniques. From the original set of features, including size, geometric and curvature descriptors, a subset of ten features are selected as predictive variables, combining a feature selection technique and area under the curve filtering. Using the washout half time (T1/2) as indicative of renal obstruction, two groups are defined. Those cases whose T1/2 is above 30 minutes are considered to be severe, while the rest would be in the safety zone, where diuretic renography could be avoided. Two different classification techniques are evaluated (logistic regression, and support vector machines). Adjusting the probability decision thresholds to operate at the point of maximum sensitivity, i.e., preventing any severe case be misclassified, specificities of 53%, and 75% are achieved, for the logistic regression and the support vector machine classifier, respectively. The proposed CAD system allows to establish a link between non-invasive non-ionizing imaging techniques and renal function, limiting the need for invasive and ionizing diuretic renography.

  5. Study on computer-aided diagnosis of hepatic MR imaging and mammography

    SciTech Connect

    Zhang Xuejun

    2005-04-01

    It is well known that the liver is an organ easily attacked by diseases. The purpose of this study is to develop a computer-aided diagnosis (CAD) scheme for helping radiologists to differentiate hepatic diseases more efficiently. Our software named LIVERANN integrated the magnetic resonance (MR) imaging findings with different pulse sequences to classify the five categories of hepatic diseases by using the artificial neural network (ANN) method. The intensity and homogeneity within the region of interest (ROI) delineated by a radiologist were automatically calculated to obtain numerical data by the program for input signals to the ANN. Outputs were the five pathological categories of hepatic diseases (hepatic cyst, hepatocellular carcinoma, dysplasia in cirrhosis, cavernous hemangioma, and metastasis). The experiment demonstrated a testing accuracy of 93% from 80 patients. In order to differentiate the cirrhosis from normal liver, the volume ratio of left to whole (LTW) was proposed to quantify the degree of cirrhosis by three-dimensional (3D) volume analysis. The liver region was firstly extracted from computed tomography (CT) or MR slices based on edge detection algorithms, and then separated into left lobe and right lobe by the hepatic umbilical fissure. The volume ratio of these two parts showed that the LTW ratio in the liver was significantly improved in the differentiation performance, with (25.6%{+-}4.3%) in cirrhosis versus the normal liver (16.4%{+-}5.4%). In addition, the application of the ANN method for detecting clustered microcalcifications in masses on mammograms was described here as well. A new structural ANN, so-called a shift-invariant artificial neural network (SIANN), was integrated with our triple-ring filter (TRF) method in our CAD system. As the result, the sensitivity of detecting clusters was improved from 90% by our previous TRF method to 95% by using both SIANN and TRF.

  6. Radiology as an aid to diagnosis in lung disease.

    PubMed

    Ellis, Stephen; Aziz, Zelena

    2016-10-01

    A great deal has changed in the imaging of chest diseases over the last 90 years. The plain chest radiograph has gone through numerous improvements and continues to be the front-line investigative technique with the mainstream adoption of digital imaging opening the doors to more advances in imaging efficacy and computer-aided diagnostics. The main change is in the advent and dramatic advances in CT, in some instances superseding the chest X-ray (CXR) as the first-line imaging investigation, not entirely to the authors' liking, and providing in vivo morphological data to aid a more specific diagnosis. However, in our view, there is a danger that the improvement in diagnostic imaging is starting to undermine clinical diagnostic acumen and that there is an increasing reliance on imaging that in the long run may not be advantageous to patient management. PMID:27535941

  7. A decision aid for diagnosis of liver lesions on MRI.

    PubMed Central

    Tombropoulos, R.; Shiffman, S.; Davidson, C.

    1993-01-01

    Abdominal magnetic resonance imaging (MRI) plays an important role in the evaluation of liver abnormalities. The interpretation of MR images requires expert training in a rapidly changing field. DAFODILL (Decision Aid for Diagnosing Liver Lesions) is a decision-support tool designed to aid radiologists in the diagnosis of hepatic lesions seen on MRI. DAFODILL uses a knowledge base of MRI findings and a belief-network inference engine to generate probabilistic differential diagnoses of the most commonly encountered hepatic lesions. DAFODILL performs limited image processing to identify clinically relevant features, which are presented to the user for confirmation before they are used by the network. Preliminary evaluation of an initial version of the system suggests that DAFODILL may be a useful tool for radiology residents and nonexpert radiologists in interpreting MR images of the liver. PMID:8130512

  8. The Sensitivity and Specificity of Using a Computer Aided Diagnosis Program for Automatically Scoring Chest X-Rays of Presumptive TB Patients Compared with Xpert MTB/RIF in Lusaka Zambia

    PubMed Central

    Muyoyeta, Monde; Maduskar, Pragnya; Moyo, Maureen; Kasese, Nkatya; Milimo, Deborah; Spooner, Rosanna; Kapata, Nathan; Hogeweg, Laurens; van Ginneken, Bram; Ayles, Helen

    2014-01-01

    Objective To determine the sensitivity and specificity of a Computer Aided Diagnosis (CAD) program for scoring chest x-rays (CXRs) of presumptive tuberculosis (TB) patients compared to Xpert MTB/RIF (Xpert). Method Consecutive presumptive TB patients with a cough of any duration were offered digital CXR, and opt out HIV testing. CXRs were electronically scored as normal (CAD score ≤60) or abnormal (CAD score>60) using a CAD program. All patients regardless of CAD score were requested to submit a spot sputum sample for testing with Xpert and a spot and morning sample for testing with LED Fluorescence Microscopy-(FM). Results Of 350 patients with evaluable data, 291 (83.1%) had an abnormal CXR score by CAD. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CXR compared to Xpert were 100% (95%CI 96.2–100), 23.2% (95%CI 18.2–28.9), 33.0% (95%CI 27.6–38.7) and 100% (95% 93.9–100), respectively. The area under the receiver operator curve (AUC) for CAD was 0.71 (95%CI 0.66–0.77). CXR abnormality correlated with smear grade (r = 0.30, p<0.0001) and with Xpert CT(r = 0.37, p<0.0001). Conclusions To our knowledge this is the first time that a CAD program for TB has been successfully tested in a real world setting. The study shows that the CAD program had high sensitivity but low specificity and PPV. The use of CAD with digital CXR has the potential to increase the use and availability of chest radiography in screening for TB where trained human resources are scarce. PMID:24705629

  9. Computer-Aided Diagnosis Scheme for Distinguishing Between Benign and Malignant Masses in Breast DCE-MRI.

    PubMed

    Honda, Emi; Nakayama, Ryohei; Koyama, Hitoshi; Yamashita, Akiyoshi

    2016-06-01

    Our purpose in this study was to develop a computer-aided diagnosis (CAD) scheme for distinguishing between benign and malignant breast masses in dynamic contrast material-enhanced magnetic resonance imaging (DCE-MRI). Our database consisted 90 DCE-MRI examinations, each of which contained four sequential phase images; this database included 28 benign masses and 62 malignant masses. In our CAD scheme, we first determined 11 objective features of masses by taking into account the image features and the dynamic changes in signal intensity that experienced radiologists commonly use for describing masses in DCE-MRI. Quadratic discriminant analysis (QDA) was employed to distinguish between benign and malignant masses. As the input of the QDA, a combination of four objective features was determined among the 11 objective features according to a stepwise method. These objective features were as follows: (i) the change in signal intensity from 2 to 5 min; (ii) the change in signal intensity from 0 to 2 min; (iii) the irregularity of the shape; and (iv) the smoothness of the margin. Using this approach, the classification accuracy, sensitivity, and specificity were shown to be 85.6 % (77 of 90), 87.1 % (54 of 62), and 82.1 % (23 of 28), respectively. Furthermore, the positive and negative predictive values were 91.5 % (54 of 59) and 74.2 % (23 of 31), respectively. Our CAD scheme therefore exhibits high classification accuracy and is useful in the differential diagnosis of masses in DCE-MRI images.

  10. Lyme disease diagnosis and treatment: lessons from the AIDS epidemic.

    PubMed

    Stricker, R B; Johnson, L

    2010-12-01

    Lyme disease is a controversial tick-borne illness that is estimated to be four times more common than AIDS in the United States. This paper outlines the challenges overcome in the healthcare response to human immunodeficiency virus (HIV) infection, the development of sensitive laboratory tests for the AIDS virus, and the promotion of long-term combination antimicrobial regimens to effectively treat HIV disease. We suggest that similar challenges need to be overcome before the chronic form of Lyme disease can be successfully treated. Currently, diagnosis and treatment of Lyme disease is hindered by the lack of a uniform case definition that adequately reflects the clinical presentation of the disease, poor laboratory test sensitivity, and high treatment failure rates using short-term monotherapy. Consequently the optimal treatment for patients with persistent symptoms of Lyme disease remains undefined. Although antibiotic monotherapy has been successful in treating early Lyme disease, the use of combination antibiotic therapy modelled on HIV treatment appears to be more effective for patients with persistent symptoms of tick-borne infection. Resolution of the controversy surrounding Lyme disease should lead to improved diagnosis and treatment modelled on the approach to HIV disease.

  11. HistoCAD: Machine Facilitated Quantitative Histoimaging with Computer Assisted Diagnosis

    NASA Astrophysics Data System (ADS)

    Tomaszewski, John E.

    Prostatic adenocarcinoma (CAP) is the most common malignancy in American men. In 2010 there will be an estimated 217,730 new cases and 32,050 deaths from CAP in the US. The diagnosis of prostatic adenocarcinoma is made exclusively from the histological evaluation of prostate tissue. The sampling protocols used to obtain 18 gauge (1.5 mm diameter) needle cores are standard sampling templates consisting of 6-12 cores performed in the context of an elevated serum value for prostate specific antigen (PSA). In this context, the prior probability of cancer is somewhat increased. However, even in this screened population, the efficiency of finding cancer is low at only approximately 20%. Histopathologists are faced with the task of reviewing the 5-10 million cores of tissue resulting from approximately 1,000,000 biopsy procedures yearly, parsing all the benign scenes from the worrisome scenes, and deciding which of the worrisome images are cancer.

  12. Three-class classification in computer-aided diagnosis of breast cancer by support vector machine

    NASA Astrophysics Data System (ADS)

    Sun, Xuejun; Qian, Wei; Song, Dansheng

    2004-05-01

    Design of classifier in computer-aided diagnosis (CAD) scheme of breast cancer plays important role to its overall performance in sensitivity and specificity. Classification of a detected object as malignant lesion, benign lesion, or normal tissue on mammogram is a typical three-class pattern recognition problem. This paper presents a three-class classification approach by using two-stage classifier combined with support vector machine (SVM) learning algorithm for classification of breast cancer on mammograms. The first classification stage is used to detect abnormal areas and normal breast tissues, and the second stage is for classification of malignant or benign in detected abnormal objects. A series of spatial, morphology and texture features have been extracted on detected objects areas. By using genetic algorithm (GA), different feature groups for different stage classification have been investigated. Computerized free-response receiver operating characteristic (FROC) and receiver operating characteristic (ROC) analyses have been employed in different classification stages. Results have shown that obvious performance improvement in both sensitivity and specificity was observed through proposed classification approach compared with conventional two-class classification approaches, indicating its effectiveness in classification of breast cancer on mammograms.

  13. Texture-based CAD improves diagnosis for low-dose CT colonography

    NASA Astrophysics Data System (ADS)

    Liang, Zhengrong; Cohen, Harris; Posniak, Erica; Fiore, Eddie; Wang, Zigang; Li, Bin; Andersen, Joseph; Harrington, Donald

    2008-03-01

    Computed tomography (CT)-based virtual colonoscopy or CT colonography (CTC) currently utilizes oral contrast solutions to tag the colonic fluid and possibly residual stool for differentiation from the colon wall and polyps. The enhanced image density of the tagged colonic materials causes a significant partial volume (PV) effect into the colon wall as well as the lumen space (filled with air or CO II). The PV effect on the colon wall can "bury" polyps of size as large as 5mm by increasing their image densities to a noticeable level, resulting in false negatives. It can also create false positives when PV effect goes into the lumen space. We have been modeling the PV effect for mixture-based image segmentation and developing text-based computer-aided detection of polyp (CADpolyp) by utilizing the PV mixture-based image segmentation. This work presents some preliminary results of developing and applying texture-based CADpolyp technique to low-dose CTC studies. A total of 114 studies of asymptomatic patients older than 50, who underwent CTC and then optical colonoscopy (OC) on the same day, were selected from a database, which was accumulated in the past decade and contains various bowel preparations and CT scanning protocols. The participating radiologists found ten polyps of greater than 5 mm from a total of 16 OC proved polyps, i.e., a detection sensitivity of 63%. They scored 23 false positives from the database, i.e., a 20% false positive rate. Approximately 70% of the datasets were marked as imperfect bowel cleansing and/or presence of image artifacts. The impact of imperfect bowel cleansing and image artifacts on VC performance is significant. The texture-based CADpolyp detected all the polyps with an average of 2.68 false positives per patient. This indicates that texture-based CADpolyp can improve the CTC performance in the cases of imperfect cleansed bowels and presence of image artifacts.

  14. CAD for small hydro projects

    SciTech Connect

    Bishop, N.A. Jr. )

    1994-04-01

    Over the past decade, computer-aided design (CAD) has become a practical and economical design tool. Today, specifying CAD hardware and software is relatively easy once you know what the design requirements are. But finding experienced CAD professionals is often more difficult. Most CAD users have only two or three years of design experience; more experienced design personnel are frequently not CAD literate. However, effective use of CAD can be the key to lowering design costs and improving design quality--a quest familiar to every manager and designer. By emphasizing computer-aided design literacy at all levels of the firm, a Canadian joint-venture company that specializes in engineering small hydroelectric projects has cut costs, become more productive and improved design quality. This article describes how they did it.

  15. Computer aided lung cancer diagnosis with deep learning algorithms

    NASA Astrophysics Data System (ADS)

    Sun, Wenqing; Zheng, Bin; Qian, Wei

    2016-03-01

    Deep learning is considered as a popular and powerful method in pattern recognition and classification. However, there are not many deep structured applications used in medical imaging diagnosis area, because large dataset is not always available for medical images. In this study we tested the feasibility of using deep learning algorithms for lung cancer diagnosis with the cases from Lung Image Database Consortium (LIDC) database. The nodules on each computed tomography (CT) slice were segmented according to marks provided by the radiologists. After down sampling and rotating we acquired 174412 samples with 52 by 52 pixel each and the corresponding truth files. Three deep learning algorithms were designed and implemented, including Convolutional Neural Network (CNN), Deep Belief Networks (DBNs), Stacked Denoising Autoencoder (SDAE). To compare the performance of deep learning algorithms with traditional computer aided diagnosis (CADx) system, we designed a scheme with 28 image features and support vector machine. The accuracies of CNN, DBNs, and SDAE are 0.7976, 0.8119, and 0.7929, respectively; the accuracy of our designed traditional CADx is 0.7940, which is slightly lower than CNN and DBNs. We also noticed that the mislabeled nodules using DBNs are 4% larger than using traditional CADx, this might be resulting from down sampling process lost some size information of the nodules.

  16. Black box integration of computer-aided diagnosis into PACS deserves a second chance: results of a usability study concerning bone age assessment.

    PubMed

    Geldermann, Ina; Grouls, Christoph; Kuhl, Christiane; Deserno, Thomas M; Spreckelsen, Cord

    2013-08-01

    Usability aspects of different integration concepts for picture archiving and communication systems (PACS) and computer-aided diagnosis (CAD) were inquired on the example of BoneXpert, a program determining the skeletal age from a left hand's radiograph. CAD-PACS integration was assessed according to its levels: data, function, presentation, and context integration focusing on usability aspects. A user-based study design was selected. Statements of seven experienced radiologists using two alternative types of integration provided by BoneXpert were acquired and analyzed using a mixed-methods approach based on think-aloud records and a questionnaire. In both variants, the CAD module (BoneXpert) was easily integrated in the workflow, found comprehensible and fitting in the conceptual framework of the radiologists. Weak points of the software integration referred to data and context integration. Surprisingly, visualization of intermediate image processing states (presentation integration) was found less important as compared to efficient handling and fast computation. Seamlessly integrating CAD into the PACS without additional work steps or unnecessary interrupts and without visualizing intermediate images may considerably improve software performance and user acceptance with efforts in time.

  17. A Computer-Aided Diagnosis System for Dynamic Contrast-Enhanced MR Images Based on Level Set Segmentation and ReliefF Feature Selection

    PubMed Central

    Zhu, Dongmei; Li, Li

    2015-01-01

    This study established a fully automated computer-aided diagnosis (CAD) system for the classification of malignant and benign masses via breast magnetic resonance imaging (BMRI). A breast segmentation method consisting of a preprocessing step to identify the air-breast interfacing boundary and curve fitting for chest wall line (CWL) segmentation was included in the proposed CAD system. The Chan-Vese (CV) model level set (LS) segmentation method was adopted to segment breast mass and demonstrated sufficiently good segmentation performance. The support vector machine (SVM) classifier with ReliefF feature selection was used to merge the extracted morphological and texture features into a classification score. The accuracy, sensitivity, and specificity measurements for the leave-half-case-out resampling method were 92.3%, 98.2%, and 76.2%, respectively. For the leave-one-case-out resampling method, the measurements were 90.0%, 98.7%, and 73.8%, respectively. PMID:25628755

  18. Comparison of sensitivity and reading time for the use of computer-aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader.

    PubMed

    Beyer, F; Zierott, L; Fallenberg, E M; Juergens, K U; Stoeckel, J; Heindel, W; Wormanns, D

    2007-11-01

    The purpose of this study was to compare sensitivity for detection of pulmonary nodules in MDCT scans and reading time of radiologists when using CAD as the second reader (SR) respectively concurrent reader (CR). Four radiologists analyzed 50 chest MDCT scans chosen from clinical routine two times and marked all detected pulmonary nodules: first with CAD as CR (display of CAD results immediately in the reading session) and later (median 14 weeks) with CAD as SR (display of CAD markers after completion of first reading without CAD). A Siemens LungCAD prototype was used. Sensitivities for detection of nodules and reading times were recorded. Sensitivity of reading with CAD as SR was significantly higher than reading without CAD (p < 0.001) and CAD as CR (p < 0.001). For nodule size of 1.75 mm or above no significant sensitivity difference between CAD as CR and reading without CAD was observed; e.g., for nodules above 4 mm sensitivity was 68% without CAD, 68% with CAD as CR (p = 0.45) and 75% with CAD as SR (p < 0.001). Reading time was significantly shorter for CR (274 s) compared to reading without CAD (294 s; p = 0.04) and SR (337 s; p < 0.001). In our study CAD could either speed up reading of chest CT cases for pulmonary nodules without relevant loss of sensitivity when used as CR, or it increased sensitivity at the cost of longer reading times when used as SR.

  19. Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.

    PubMed

    Du, Guo-Qing; Xue, Jing-Yi; Guo, Yanhui; Chen, Shuang; Du, Pei; Wu, Yan; Wang, Yu-Hang; Zong, Li-Qiu; Tian, Jia-Wei

    2015-09-01

    Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can

  20. Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.

    PubMed

    Du, Guo-Qing; Xue, Jing-Yi; Guo, Yanhui; Chen, Shuang; Du, Pei; Wu, Yan; Wang, Yu-Hang; Zong, Li-Qiu; Tian, Jia-Wei

    2015-09-01

    Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can

  1. The diagnosis of CAD in women: addressing the unmet need - a report from the national expert roundtable meeting.

    PubMed

    Clarke, Janice L; Ladapo, Joseph L; Monane, Mark; Lansky, Alexandra; Skoufalos, Alexandria; Nash, David B

    2015-04-01

    A multistakeholder panel comprising experts in the fields of clinical cardiology, medical technology innovation, women's health research and policy analysis, personalized medicine, payers (including self-insured employers), patient advocacy, and health economics was convened at the Heart House in Washington, DC. The following points emerged as key concepts: (1) Diagnostic challenges in the evaluation of women with symptoms suggestive of obstructive coronary artery disease (CAD) result from: (a) presentation with atypical symptoms and lower pretest probability of disease compared to men, (b) fatty tissue and breast tissue attenuation on cardiac imaging leading to false positive findings, and (c) the presence of microvascular CAD. (2) Diagnostic challenges lead to both over-testing of low-risk women and under-testing of high-risk women. (3) Efforts should be directed toward increasing clinician, clinical professional society, and consumer awareness and understanding of sex-specific differences between men and women in the pathophysiology of CAD. (4) Multiple health care stakeholders should be made aware of new advances in genomic approaches to address the challenges of diagnosing obstructive CAD; specifically, the Corus CAD gene expression test, which was shown to have high sensitivity and negative predictive value in a recent clinical trial. As such, it has promise as a tool to help clinicians to rule out obstructive CAD as a cause of a patient's symptoms. (Population Health Management 2015;18:86-92).

  2. TRAD or CAD? A Comparison.

    ERIC Educational Resources Information Center

    Resetarits, Paul J.

    1989-01-01

    Studies whether traditional drafting equipment (TRAD) or computer aided drafting equipment (CAD) is more effective. Proposes that students using only CAD can learn principles of drafting as well as students using only TRAD. Reports no significant difference either on achievement or attitude. (MVL)

  3. Computer-aided diagnosis of diagnostically challenging lesions in breast MRI: a comparison between a radiomics and a feature-selective approach

    NASA Astrophysics Data System (ADS)

    Hoffmann, Sebastian; Lobbes, Marc; Houben, Ivo; Pinker-Domenig, Katja; Wengert, Georg; Burgeth, Bernhard; Meyer-Bäse, Uwe; Lemaitre, Guillaume; Meyer-Baese, Anke

    2016-05-01

    Diagnostically challenging lesions pose a challenge both for the radiological reading and also for current CAD systems. They are not well-defined in both morphology (geometric shape) and kinetics (temporal enhancement) and pose a problem to lesion detection and classification. Their strong phenotypic differences can be visualized by MRI. Radiomics represents a novel approach to achieve a detailed quantification of the tumour phenotypes by analyzing a large number of image descriptors. In this paper, we apply a quantitative radiomics approach based on shape, texture and kinetics tumor features and evaluate it in comparison to a reduced-order feature approach in a computer-aided diagnosis system applied to diagnostically challenging lesions.

  4. Computer-Aided Diagnosis for Breast Ultrasound Using Computerized BI-RADS Features and Machine Learning Methods.

    PubMed

    Shan, Juan; Alam, S Kaisar; Garra, Brian; Zhang, Yingtao; Ahmed, Tahira

    2016-04-01

    This work identifies effective computable features from the Breast Imaging Reporting and Data System (BI-RADS), to develop a computer-aided diagnosis (CAD) system for breast ultrasound. Computerized features corresponding to ultrasound BI-RADs categories were designed and tested using a database of 283 pathology-proven benign and malignant lesions. Features were selected based on classification performance using a "bottom-up" approach for different machine learning methods, including decision tree, artificial neural network, random forest and support vector machine. Using 10-fold cross-validation on the database of 283 cases, the highest area under the receiver operating characteristic (ROC) curve (AUC) was 0.84 from a support vector machine with 77.7% overall accuracy; the highest overall accuracy, 78.5%, was from a random forest with the AUC 0.83. Lesion margin and orientation were optimum features common to all of the different machine learning methods. These features can be used in CAD systems to help distinguish benign from worrisome lesions.

  5. Computer-aided diagnosis of plus disease via measurement of vessel thickness in retinal fundus images of preterm infants.

    PubMed

    Oloumi, Faraz; Rangayyan, Rangaraj M; Casti, Paola; Ells, Anna L

    2015-11-01

    Changes in the characteristics of retinal vessels such as width and tortuosity can be signs of the presence of several diseases such retinopathy of prematurity (ROP) and diabetic retinopathy. Plus disease is an indicator of ROP which requires treatment and is signified by an increase in posterior venular width. In this work, we present image processing techniques for the detection, segmentation, tracking, and measurement of the width of the major temporal arcade (MTA), which is the thickest venular branch in the retina. Several image processing techniques have been employed, including the use of Gabor filters to detect the MTA, morphological image processing to obtain its skeleton, Canny's method to detect and select MTA vessel-edge candidates, least-squares fitting to interpolate the MTA edges, and geometrical procedures to measure the width of the MTA. The results, obtained using 110 retinal fundus images of preterm infants, indicate a statistically highly significant difference in MTA width of normal cases as compared to cases with plus disease (p<0.01). The results provide good accuracy in computer-aided diagnosis (CAD) of plus disease with an area under the receiver operating characteristic curve of 0.76. The proposed methods may be used in CAD of plus disease and timely treatment of ROP in a clinical or teleophthalmological setting.

  6. Incorporating texture features in a computer-aided breast lesion diagnosis system for automated three-dimensional breast ultrasound

    PubMed Central

    Liu, Haixia; Tan, Tao; van Zelst, Jan; Mann, Ritse; Karssemeijer, Nico; Platel, Bram

    2014-01-01

    Abstract. We investigated the benefits of incorporating texture features into an existing computer-aided diagnosis (CAD) system for classifying benign and malignant lesions in automated three-dimensional breast ultrasound images. The existing system takes into account 11 different features, describing different lesion properties; however, it does not include texture features. In this work, we expand the system by including texture features based on local binary patterns, gray level co-occurrence matrices, and Gabor filters computed from each lesion to be diagnosed. To deal with the resulting large number of features, we proposed a combination of feature-oriented classifiers combining each group of texture features into a single likelihood, resulting in three additional features used for the final classification. The classification was performed using support vector machine classifiers, and the evaluation was done with 10-fold cross validation on a dataset containing 424 lesions (239 benign and 185 malignant lesions). We compared the classification performance of the CAD system with and without texture features. The area under the receiver operating characteristic curve increased from 0.90 to 0.91 after adding texture features (p<0.001). PMID:26158036

  7. Computer-aided diagnosis workstation and network system for chest diagnosis based on multislice CT images

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Moriyama, Noriyuki; Ohmatsu, Hironobu; Masuda, Hideo; Machida, Suguru

    2008-03-01

    Mass screening based on multi-helical CT images requires a considerable number of images to be read. It is this time-consuming step that makes the use of helical CT for mass screening impractical at present. To overcome this problem, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images, a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification and a vertebra body analysis algorithm for quantitative evaluation of osteoporosis likelihood by using helical CT scanner for the lung cancer mass screening. The function to observe suspicious shadow in detail are provided in computer-aided diagnosis workstation with these screening algorithms. We also have developed the telemedicine network by using Web medical image conference system with the security improvement of images transmission, Biometric fingerprint authentication system and Biometric face authentication system. Biometric face authentication used on site of telemedicine makes "Encryption of file" and Success in login" effective. As a result, patients' private information is protected. Based on these diagnostic assistance methods, we have developed a new computer-aided workstation and a new telemedicine network that can display suspected lesions three-dimensionally in a short time. The results of this study indicate that our radiological information system without film by using computer-aided diagnosis workstation and our telemedicine network system can increase diagnostic speed, diagnostic accuracy and security improvement of medical information.

  8. Semiautomatic segmentation for the computer aided diagnosis of clustered microcalcifications

    NASA Astrophysics Data System (ADS)

    Elter, Matthias; Held, Christian

    2008-03-01

    Screening mammography is recognized as the most effective tool for early breast cancer detection. However, its application in clinical practice shows some of its weaknesses. While clustered microcalcifications are often an early sign of breast cancer, the discrimination of benign from malignant clusters based on their appearance in mammograms is a very difficult task. Hence, it is not surprising that typically only 15% to 30% of breast biopsies performed on calcifications will be positive for malignancy. As this low positive predictive value of mammography regarding the diagnosis of calcification clusters results in many unnecessary biopsies performed on benign calcifications, we propose a novel computer aided diagnosis (CADx) approach with the goal to improve the reliability of microcalcification classification. As effective automatic classification of microcalcification clusters relies on good segmentations of the individual calcification particles, many approaches to the automatic segmentation of individual particles have been proposed in the past. Because none of the fully automatic approaches seem to result in optimal segmentations, we propose a novel semiautomatic approach that has automatic components but also allows some interaction of the radiologist. Based on the resulting segmentations we extract a broad range of features that characterize the morphology and distribution of calcification particles. Using regions of interest containing either benign or malignant clusters extracted from the digital database for screening mammography we evaluate the performance of our approach using a support vector machine and ROC analysis. The resulting ROC performance is very promising and we show that the performance of our semiautomatic segmentation is significantly higher than that of a comparable fully automatic approach.

  9. Application of Fisher fusion techniques to improve the individual performance of sonar computer-aided detection/computer-aided classification (CAD/CAC) algorithms

    NASA Astrophysics Data System (ADS)

    Ciany, Charles M.; Zurawski, William C.

    2009-05-01

    Raytheon has extensively processed high-resolution sidescan sonar images with its CAD/CAC algorithms to provide classification of targets in a variety of shallow underwater environments. The Raytheon CAD/CAC algorithm is based on non-linear image segmentation into highlight, shadow, and background regions, followed by extraction, association, and scoring of features from candidate highlight and shadow regions of interest (ROIs). The targets are classified by thresholding an overall classification score, which is formed by summing the individual feature scores. The algorithm performance is measured in terms of probability of correct classification as a function of false alarm rate, and is determined by both the choice of classification features and the manner in which the classifier rates and combines these features to form its overall score. In general, the algorithm performs very reliably against targets that exhibit "strong" highlight and shadow regions in the sonar image- i.e., both the highlight echo and its associated shadow region from the target are distinct relative to the ambient background. However, many real-world undersea environments can produce sonar images in which a significant percentage of the targets exhibit either "weak" highlight or shadow regions in the sonar image. The challenge of achieving robust performance in these environments has traditionally been addressed by modifying the individual feature scoring algorithms to optimize the separation between the corresponding highlight or shadow feature scores of targets and non-targets. This study examines an alternate approach that employs principles of Fisher fusion to determine a set of optimal weighting coefficients that are applied to the individual feature scores before summing to form the overall classification score. The results demonstrate improved performance of the CAD/CAC algorithm on at-sea data sets.

  10. IGIS (Interactive Geologic Interpretation System) computer-aided photogeologic mapping with image processing, graphics and CAD/CAM capabilities

    SciTech Connect

    McGuffie, B.A.; Johnson, L.F.; Alley, R.E.; Lang, H.R. )

    1989-10-01

    Advances in computer technology are changing the way geologists integrate and use data. Although many geoscience disciplines are absolutely dependent upon computer processing, photogeological and map interpretation computer procedures are just now being developed. Historically, geologists collected data in the field and mapped manually on a topographic map or aerial photographic base. New software called the interactive Geologic Interpretation System (IGIS) is being developed at the Jet Propulsion Laboratory (JPL) within the National Aeronautics and Space Administration (NASA)-funded Multispectral Analysis of Sedimentary Basins Project. To complement conventional geological mapping techniques, Landsat Thematic Mapper (TM) or other digital remote sensing image data and co-registered digital elevation data are combined using computer imaging, graphics, and CAD/CAM techniques to provide tools for photogeologic interpretation, strike/dip determination, cross section construction, stratigraphic section measurement, topographic slope measurement, terrain profile generation, rotatable 3-D block diagram generation, and seismic analysis.

  11. CAD May Not be Necessary for Microcalcifications in the Digital era, CAD May Benefit Radiologists for Masses

    PubMed Central

    Destounis, Stamatia V.; Arieno, Andrea L.; Morgan, Renee C.

    2012-01-01

    Objective: The aim of this study was to evaluate the effectiveness of computer-aided detection (CAD) to mark the cancer on digital mammograms at the time of breast cancer diagnosis and also review retrospectively whether CAD marked the cancer if visible on any available prior mammograms, thus potentially identifying breast cancer at an earlier stage. We sought to determine why breast lesions may or may not be marked by CAD. In particular, we analyzed factors such as breast density, mammographic views, and lesion characteristics. Materials and Methods: Retrospective review from 2004 to 2008 revealed 3445 diagnosed breast cancers in both symptomatic and asymptomatic patients; 1293 of these were imaged with full field digital mammography (FFDM). After cancer diagnosis, in a retrospective review held by the radiologist staff, 43 of these cancers were found to be visible on prior-year mammograms (false-negative cases); these breast cancer cases are the basis of this analysis. All cases had CAD evaluation available at the time of cancer diagnosis and on prior mammography studies. Data collected included patient demographics, breast density, palpability, lesion type, mammographic size, CAD marks on current- and prior-year mammograms, needle biopsy method, pathology results (core needle and/or surgical), surgery type, and lesion size. Results: On retrospective review of the mammograms by the staff radiologists, 43 cancers were discovered to be visible on prior-year mammograms. All 43 cancers were masses (mass classification included mass, mass with calcification, and mass with architectural distortion); no pure microcalcifications were identified in this cohort. Mammograms with CAD applied at the time of breast cancer diagnosis were able to detect 79% (34/43) of the cases and 56% (24/43) from mammograms with CAD applied during prior year(s). In heterogeneously dense/extremely dense tissue, CAD marked 79% (27/34) on mammograms taken at the time of diagnosis and 56% (19

  12. Image-based retrieval system and computer-aided diagnosis system for renal cortical scintigraphy images

    NASA Astrophysics Data System (ADS)

    Mumcuoğlu, Erkan; Nar, Fatih; Uğur, Omer; Bozkurt, M. Fani; Aslan, Mehmet

    2008-03-01

    Cortical renal (kidney) scintigraphy images are 2D images (256x256) acquired in three projection angles (posterior, right-posterior-oblique and left-posterior-oblique). These images are used by nuclear medicine specialists to examine the functional morphology of kidney parenchyma. The main visual features examined in reading the images are: size, location, shape and activity distribution (pixel intensity distribution within the boundary of each kidney). Among the above features, activity distribution (in finding scars if any) was found to have the least interobserver reproducibility. Therefore, in this study, we developed an image-based retrieval (IBR) and a computer-based diagnosis (CAD) system, focused on this feature in particular. The developed IBR and CAD algorithms start with automatic segmentation, boundary and landmark detection. Then, shape and activity distribution features are computed. Activity distribution feature is obtained using the acquired image and image set statistics of the normal patients. Active Shape Model (ASM) technique is used for more accurate kidney segmentation. In the training step of ASM, normal patient images are used. Retrieval performance is evaluated by calculating precision and recall. CAD performance is evaluated by specificity and sensitivity. To our knowledge, this paper is the first IBR or CAD system reported in the literature on renal cortical scintigraphy images.

  13. A hybrid feature-based segmentation and classification system for the computer aided self-diagnosis of otitis media.

    PubMed

    Shie, Chuen-Kai; Chang, Hao-Ting; Fan, Fu-Cheng; Chen, Chung-Jung; Fang, Te-Yung; Wang, Pa-Chun

    2014-01-01

    We propose a novel hybrid otitis media (OM) computer aided detection (CAD) system, designed to aid in the self-diagnosis of various forms of OM. OM is a prevalent disease in both children and adults. Our system is able to differentiate normal ear from acute otitis media (AOM), otitis media with effusion (OME) and the multi-categories of chronic otitis media including perforation, retraction, cholesteatoma, etc. We propose a modified double active contour segmentation method designed for use with otoscope images, and enabled to handle user acquired data. To describe the visual symptoms (e.g., red, bulging, effusion, perforation, retraction, etc.) of otitis media accurately, we extract color, geometric and texture features by grid color moment, Gabor filter, local binary pattern and histogram of oriented gradients. A powerful classification structure based on Adaboost is used to select the most useful features and build a strong classifier. Our system achieves classification accuracy as high as 88.06% and is suitable for real use. In addition, some interesting observations about OM otoscope images are also discussed.

  14. Assessment methodologies and statistical issues for computer-aided diagnosis of lung nodules in computed tomography: contemporary research topics relevant to the lung image database consortium.

    PubMed

    Dodd, Lori E; Wagner, Robert F; Armato, Samuel G; McNitt-Gray, Michael F; Beiden, Sergey; Chan, Heang-Ping; Gur, David; McLennan, Geoffrey; Metz, Charles E; Petrick, Nicholas; Sahiner, Berkman; Sayre, Jim

    2004-04-01

    Cancer of the lung and bronchus is the leading fatal malignancy in the United States. Five-year survival is low, but treatment of early stage disease considerably improves chances of survival. Advances in multidetector-row computed tomography technology provide detection of smaller lung nodules and offer a potentially effective screening tool. The large number of images per exam, however, requires considerable radiologist time for interpretation and is an impediment to clinical throughput. Thus, computer-aided diagnosis (CAD) methods are needed to assist radiologists with their decision making. To promote the development of CAD methods, the National Cancer Institute formed the Lung Image Database Consortium (LIDC). The LIDC is charged with developing the consensus and standards necessary to create an image database of multidetector-row computed tomography lung images as a resource for CAD researchers. To develop such a prospective database, its potential uses must be anticipated. The ultimate applications will influence the information that must be included along with the images, the relevant measures of algorithm performance, and the number of required images. In this article we outline assessment methodologies and statistical issues as they relate to several potential uses of the LIDC database. We review methods for performance assessment and discuss issues of defining "truth" as well as the complications that arise when truth information is not available. We also discuss issues about sizing and populating a database.

  15. Comparison of sensitivity and reading time for the use of computer aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader

    NASA Astrophysics Data System (ADS)

    Beyer, F.; Zierott, L.; Fallenberg, E. M.; Juergens, K.; Stoeckel, J.; Heindel, W.; Wormanns, D.

    2006-03-01

    Purpose: To compare sensitivity and reading time when using CAD as second reader resp. concurrent reader. Materials and Methods: Fifty chest MDCT scans due to clinical indication were analysed independently by four radiologists two times: First with CAD as concurrent reader (display of CAD results simultaneously to the primary reading by the radiologist); then after a median of 14 weeks with CAD as second reader (CAD results were shown after completion of a reading session without CAD). A prototype version of Siemens LungCAD (Siemens,Malvern,USA) was used. Sensitivities and reading times for detecting nodules >=4mm of concurrent reading, reading without CAD and second reading were recorded. In a consensus conference false positive findings were eliminated. Student's T-Test was used to compare sensitivities and reading times. Results: 108 true positive nodules were found. Mean sensitivity was .68 for reading without CAD, .68 for concurrent reading and .75 for second reading. Differences of sensitivities were significant between concurrent and second reading (p<.001) resp. reading without CAD and second reading (p=.001). Mean reading time for concurrent reading was significant shorter (274s) compared to reading without CAD (294s;p=.04) and second reading (337sp<.001). New work to be presented: To our knowledge this is the first study that compares sensitivities and reading times between use of CAD as concurrent resp. second reader. Conclusion: CAD can either be used to speed up reading of chest CT cases for pulmonary nodules without loss of sensitivity as concurrent reader -OR (and not AND) to increase sensitivity and reading time as second reader.

  16. Computer Aided Instruction and Problem Solving in the Teaching of Oral Diagnosis.

    ERIC Educational Resources Information Center

    Spencer, Judson; Gobetti, John P.

    A computer-assisted instructional (CAI) program is being used at the University of Michigan School of Dentistry to aid in the teaching of oral diagnosis to dental students. The program is designed to simulate a real life situation--i.e., the diagnosis of patient illness-which would not be otherwise available to the student and to demonstrate to…

  17. Computer-aided diagnosis of pulmonary nodules on CT scans: Segmentation and classification using 3D active contours

    PubMed Central

    Way, Ted W.; Hadjiiski, Lubomir M.; Sahiner, Berkman; Chan, Heang-Ping; Cascade, Philip N.; Kazerooni, Ella A.; Bogot, Naama; Zhou, Chuan

    2009-01-01

    We are developing a computer-aided diagnosis (CAD) system to classify malignant and benign lung nodules found on CT scans. A fully automated system was designed to segment the nodule from its surrounding structured background in a local volume of interest (VOI) and to extract image features for classification. Image segmentation was performed with a three-dimensional (3D) active contour (AC) method. A data set of 96 lung nodules (44 malignant, 52 benign) from 58 patients was used in this study. The 3D AC model is based on two-dimensional AC with the addition of three new energy components to take advantage of 3D information: (1) 3D gradient, which guides the active contour to seek the object surface, (2) 3D curvature, which imposes a smoothness constraint in the z direction, and (3) mask energy, which penalizes contours that grow beyond the pleura or thoracic wall. The search for the best energy weights in the 3D AC model was guided by a simplex optimization method. Morphological and gray-level features were extracted from the segmented nodule. The rubber band straightening transform (RBST) was applied to the shell of voxels surrounding the nodule. Texture features based on run-length statistics were extracted from the RBST image. A linear discriminant analysis classifier with stepwise feature selection was designed using a second simplex optimization to select the most effective features. Leave-one-case-out resampling was used to train and test the CAD system. The system achieved a test area under the receiver operating characteristic curve (Az) of 0.83±0.04. Our preliminary results indicate that use of the 3D AC model and the 3D texture features surrounding the nodule is a promising approach to the segmentation and classification of lung nodules with CAD. The segmentation performance of the 3D AC model trained with our data set was evaluated with 23 nodules available in the Lung Image Database Consortium (LIDC). The lung nodule volumes segmented by the 3D AC

  18. Iterative method for automatic detection of masses in digital mammograms for computer-aided diagnosis

    NASA Astrophysics Data System (ADS)

    Martinez, Victor G.; Gamo, Daniel M.; Rios, Juan; Vilarrasa, Amparo

    1999-05-01

    An iterative algorithm has been developed for automatic detection of breast masses from digitalized mammograms. The procedure has been divided in two stages. The first one based on the histogram analysis of the input image. The second one employs a topological analysis from the results obtained in the first stage. The final output is a set of interest regions that are defined as suspicious areas by the system. These suspicious regions should be harder studied in order to present a final diagnosis. The developed system may be used together with any other suspicious area diagnosis algorithms. In this way a computer assisted diagnosis (CAD) program to assist radiologists in his mammography interpretation task could be easy developed.

  19. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery.

    PubMed

    Motohashi, N; Kuroda, T

    1999-06-01

    The purpose of this article is to describe a newly developed 3D computer-aided design (CAD) system for the diagnostic set-up of casts in orthodontic diagnosis and treatment planning, and its preliminary clinical applications. The system comprises a measuring unit which obtains 3D information from the dental model using laser scanning, and a personal computer to generate the 3D graphics. When measuring the 3D shape of the model, to minimize blind sectors, the model is scanned from two different directions with the slit-ray laser beam by rotating the mounting angle of the model on the measuring device. For computed simulation of tooth movement, the representative planes, defined by the anatomical reference points, are formed for each individual tooth and are arranged along a guideline descriptive of the individual arch form. Subsequently, the 3D shape is imparted to each of the teeth arranged on the representative plane to form an arrangement of the 3D profile. When necessary, orthognathic surgery can be simulated by moving the mandibular dental arch three-dimensionally to establish the optimum occlusal relationship. Compared with hand-made set-up models, the computed diagnostic cast has advantages such as high-speed processing and quantitative evaluation on the amount of 3D movement of the individual tooth relative to the craniofacial plane. Trial clinical applications demonstrated that the use of this system facilitated the otherwise complicated and time-consuming mock surgery for treatment planning in orthognathic surgery.

  20. Acute leukemia diagnosis aid using multicriteria fuzzy assignment methodology.

    PubMed

    Belacel, N; Vincke, P; Scheiff, J M; Boulassel, M R

    2001-02-01

    We recently developed a new multicriteria classification method called PROAFTN to help medical diagnosis. The aim of this paper is to present the application of the proposed method for the diagnosis of acute leukemia (AL). The implementation of PROAFTN was carried out on cytological data of 108 cases of AL, using the classification rules of French, American and British hematologists, and was then applied on an independent test set of 83 cases of AL. Forty-seven features, obtained by examining patients' bone-marrow smears with light microscope, defined each case. In order to determine the percentage of correct classifications for each subtype of AL, we compared our results with the clinical diagnosis given previously by the hematologist. 96.4% of the cases were correctly classified by the program, suggesting that the method yields good results in terms of discrimination between AL subtypes.

  1. Viewing CAD Drawings on the Internet

    ERIC Educational Resources Information Center

    Schwendau, Mark

    2004-01-01

    Computer aided design (CAD) has been producing 3-D models for years. AutoCAD software is frequently used to create sophisticated 3-D models. These CAD files can be exported as 3DS files for import into Autodesk's 3-D Studio Viz. In this program, the user can render and modify the 3-D model before exporting it out as a WRL (world file hyperlinked)…

  2. Computing Mass Properties From AutoCAD

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1990-01-01

    Mass properties of structures computed from data in drawings. AutoCAD to Mass Properties (ACTOMP) computer program developed to facilitate quick calculations of mass properties of structures containing many simple elements in such complex configurations as trusses or sheet-metal containers. Mathematically modeled in AutoCAD or compatible computer-aided design (CAD) system in minutes by use of three-dimensional elements. Written in Microsoft Quick-Basic (Version 2.0).

  3. Immersive CAD

    SciTech Connect

    Ames, A.L.

    1999-02-01

    This paper documents development of a capability for performing shape-changing editing operations on solid model representations in an immersive environment. The capability includes part- and assembly-level operations, with part modeling supporting topology-invariant and topology-changing modifications. A discussion of various design considerations in developing an immersive capability is included, along with discussion of a prototype implementation we have developed and explored. The project investigated approaches to providing both topology-invariant and topology-changing editing. A prototype environment was developed to test the approaches and determine the usefulness of immersive editing. The prototype showed exciting potential in redefining the CAD interface. It is fun to use. Editing is much faster and friendlier than traditional feature-based CAD software. The prototype algorithms did not reliably provide a sufficient frame rate for complex geometries, but has provided the necessary roadmap for development of a production capability.

  4. CAD Services: an Industry Standard Interface for Mechanical CAD Interoperability

    NASA Technical Reports Server (NTRS)

    Claus, Russell; Weitzer, Ilan

    2002-01-01

    Most organizations seek to design and develop new products in increasingly shorter time periods. At the same time, increased performance demands require a team-based multidisciplinary design process that may span several organizations. One approach to meet these demands is to use 'Geometry Centric' design. In this approach, design engineers team their efforts through one united representation of the design that is usually captured in a CAD system. Standards-based interfaces are critical to provide uniform, simple, distributed services that enable the 'Geometry Centric' design approach. This paper describes an industry-wide effort, under the Object Management Group's (OMG) Manufacturing Domain Task Force, to define interfaces that enable the interoperability of CAD, Computer Aided Manufacturing (CAM), and Computer Aided Engineering (CAE) tools. This critical link to enable 'Geometry Centric' design is called: Cad Services V1.0. This paper discusses the features of this standard and proposed application.

  5. Rapid diagnosis of cytomegalovirus in Thai pediatric AIDS patients.

    PubMed

    Tantivanich, Surang; Sawatmongkonkun, Wandee; Balachandra, Kruavan; Chotpitayasunondh, Tawee; Amarapal, Pomsawan

    2002-06-01

    Blood samples were collected from 100 pediatric AIDS patients for the detection of CMV in pp65-bearing leukocytes (PBLs) by immunoperoxidase staining (IP) and PCR. IgM antibody assay was performed to determine the correlation of antigen and antibody. IP and PCR can be used as methods for the early detection of CMV (prior to the presence of IgM antibody). The sensitivity and specificity of IP were 73% and 97% respectively. IP is superior to PCR in several ways: it is very easy to perform, less time consuming, less expensive, and does not require expensive instruments.

  6. Computer aided differential diagnosis in emergency situations (CADDIES) system

    SciTech Connect

    NOEL,WILLIAM P.

    2000-03-01

    This report presents an idea for a portable computerized differential diagnosis tool that could be utilized by a health care provider during an emergency situation. This radio frequency, networked, menu driven system would analyze various patient assessment parameters and make recommendations regarding possible diagnoses/treatment options outside the scope of suspicion of the health care provider. This system would serve as a repository for initial epidemiological data and assist the health care provider with spotting emerging trends.

  7. Comparing performance of the CADstream and the DynaCAD breast MRI CAD systems : CADstream vs. DynaCAD in breast MRI.

    PubMed

    Pan, Joann; Dogan, Basak E; Carkaci, Selin; Santiago, Lumarie; Arribas, Elsa; Cantor, Scott B; Wei, Wei; Stafford, R Jason; Whitman, Gary J

    2013-10-01

    Computer-aided diagnosis (CAD) systems are software programs that use algorithms to find patterns associated with breast cancer on breast magnetic resonance imaging (MRI). The most commonly used CAD systems in the USA are CADstream (CS) (Merge Healthcare Inc., Chicago, IL) and DynaCAD for Breast (DC) (Invivo, Gainesville, FL). Our primary objective in this study was to compare the CS and DC breast MRI CAD systems for diagnostic accuracy and postprocessed image quality. Our secondary objective was to compare the evaluation times of radiologists using each system. Three radiologists evaluated 30 biopsy-proven malignant lesions and 29 benign lesions on CS and DC and rated the lesions' malignancy status using the Breast Imaging Reporting and Data System. Image quality was ranked on a 0-5 scale, and mean reading times were also recorded. CS detected 70 % of the malignant and 32 % of the benign lesions while DC detected 81 % of the malignant lesions and 34 % of the benign lesions. Analysis of the area under the receiver operating characteristic curve revealed that the difference in diagnostic performance was not statistically significant. On image quality scores, CS had significantly higher volume rendering (VR) (p < 0.0001) and motion correction (MC) scores (p < 0.0001). There were no statistically significant differences in the remaining image quality scores. Differences in evaluation times between DC and CS were also not statistically significant. We conclude that both CS and DC perform similarly in aiding detection of breast cancer on MRI. MRI CAD selection will likely be based on other factors, such as user interface and image quality preferences, including MC and VR. PMID:23589186

  8. Assessment of the Incremental Benefit of Computer-Aided Detection (CAD) for Interpretation of CT Colonography by Experienced and Inexperienced Readers

    PubMed Central

    Boone, Darren; Mallett, Susan; McQuillan, Justine; Taylor, Stuart A.; Altman, Douglas G.; Halligan, Steve

    2015-01-01

    Objectives To quantify the incremental benefit of computer-assisted-detection (CAD) for polyps, for inexperienced readers versus experienced readers of CT colonography. Methods 10 inexperienced and 16 experienced radiologists interpreted 102 colonography studies unassisted and with CAD utilised in a concurrent paradigm. They indicated any polyps detected on a study sheet. Readers’ interpretations were compared against a ground-truth reference standard: 46 studies were normal and 56 had at least one polyp (132 polyps in total). The primary study outcome was the difference in CAD net benefit (a combination of change in sensitivity and change in specificity with CAD, weighted towards sensitivity) for detection of patients with polyps. Results Inexperienced readers’ per-patient sensitivity rose from 39.1% to 53.2% with CAD and specificity fell from 94.1% to 88.0%, both statistically significant. Experienced readers’ sensitivity rose from 57.5% to 62.1% and specificity fell from 91.0% to 88.3%, both non-significant. Net benefit with CAD assistance was significant for inexperienced readers but not for experienced readers: 11.2% (95%CI 3.1% to 18.9%) versus 3.2% (95%CI -1.9% to 8.3%) respectively. Conclusions Concurrent CAD resulted in a significant net benefit when used by inexperienced readers to identify patients with polyps by CT colonography. The net benefit was nearly four times the magnitude of that observed for experienced readers. Experienced readers did not benefit significantly from concurrent CAD. PMID:26355745

  9. Cell-free DNA testing: an aid to prenatal sonographic diagnosis.

    PubMed

    Chitty, Lyn S

    2014-04-01

    Sonographic diagnosis of fetal abnormalities is based on the recognition of sonographic patterns associated with structural abnormalities. Although diagnosis in some situations, such as neural tube defects, gastroschisis, and omphalocoele, can be straightforward, in many situations, the constellation of fetal abnormalities suggest an underlying chromosomal or genetic cause. In these situations, invasive testing is needed to provide the information required to make a definitive diagnosis, and thus accurately counsel parents. Since the identification of cell-free fetal DNA in maternal plasma, the potential for non-invasive prenatal diagnosis is increasingly becoming possible. In this chapter, the current role and future potential of non-invasive prenatal diagnosis, combined with new molecular techniques as an aid to sonographic diagnosis, will be discussed.

  10. Echocardiography in congenital heart disease. An aid to surgical diagnosis.

    PubMed

    Meyer, R A

    1977-05-01

    Echocardiography is an important noninvasive method for accurately diagnosing many congenital cardiac defects. This method provides significant information so that cardiac surgery, when necessary, can be planned with greater facility. The value of the sonar method rests not only on its ability to diagnose specific cardiac defects but also to exclude heart disease, especially in infants with shock or cyanosis from noncardiac causes. Development of two-dimensional real-time scanning systems should provide greater understanding of anatomic spatial relationships and ease of diagnosis.

  11. False positive reduction for lung nodule CAD

    NASA Astrophysics Data System (ADS)

    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.

  12. Computer-aided diagnosis system: a Bayesian hybrid classification method.

    PubMed

    Calle-Alonso, F; Pérez, C J; Arias-Nicolás, J P; Martín, J

    2013-10-01

    A novel method to classify multi-class biomedical objects is presented. The method is based on a hybrid approach which combines pairwise comparison, Bayesian regression and the k-nearest neighbor technique. It can be applied in a fully automatic way or in a relevance feedback framework. In the latter case, the information obtained from both an expert and the automatic classification is iteratively used to improve the results until a certain accuracy level is achieved, then, the learning process is finished and new classifications can be automatically performed. The method has been applied in two biomedical contexts by following the same cross-validation schemes as in the original studies. The first one refers to cancer diagnosis, leading to an accuracy of 77.35% versus 66.37%, originally obtained. The second one considers the diagnosis of pathologies of the vertebral column. The original method achieves accuracies ranging from 76.5% to 96.7%, and from 82.3% to 97.1% in two different cross-validation schemes. Even with no supervision, the proposed method reaches 96.71% and 97.32% in these two cases. By using a supervised framework the achieved accuracy is 97.74%. Furthermore, all abnormal cases were correctly classified.

  13. Virus morphology as an aid for rapid diagnosis.

    PubMed Central

    Doane, F. W.

    1980-01-01

    Standard methods of virus diagnosis may take many days to complete. As antiviral drugs are being used with more effectiveness, it becomes more important to develop rapid diagnostic methods. It takes only a few minutes to prepare and examine a specimen for electron microscopy (EM), using the negative staining technique. Viruses in the specimen can readily be identified by their morphology. In order to be detected by EM there must be at least 10(7) virus particles per milliliter of sample. This concentration is frequently found in certain types of specimens. The sensitivity of EM is increased 100-fold if homologous antibody is used to aggregate the virus. Visualization of virus-antibody aggregates forms the basis for serotyping by immunoelectron microscopy (IEM). Images PLATE 1 PLATE 2 PLATE 3 PMID:6155006

  14. Utility and effectiveness of computer-aided diagnosis of dental caries.

    PubMed

    Tracy, Kyle D; Dykstra, Bradley A; Gakenheimer, David C; Scheetz, James P; Lacina, Stephani; Scarfe, William C; Farman, Allan G

    2011-01-01

    Digital radiography has created a growing opportunity for computer-aided diagnostic (CAD) tools. The Logicon Caries Detector (LCD), with upgraded CAD software based on user feedback, was re-evaluated for its effectiveness via a retrospective clinical study. Using the upgraded LCD software, 12 dentists (evaluators) blindly assessed 17 radiographs taken by another (attending) dentist, who restored 28 proximal surfaces. The attending dentist confirmed the presence of early dentinal caries, as well as identifying 48 surfaces as caries-free or with enamel caries only subject to noninvasive treatment. The radiographs, imported into the software using a digital imaging and communications in medicine (DICOM) reader, were visually assessed under typical operatory lighting conditions, then with the aid of the software's density analysis tool. The effectiveness of the evaluators was gauged by calculating two measures of performance, sensitivity and specificity, for the detection and classification of dentinal caries. Sensitivity among all evaluator dentists was 30% with the initial image; 34% with the brightness and contrast adjusted image; 39% when the image was sharpened; and 69% when the density analysis tool was utilized. Specificity was found to be 97% with the initial image; 95% with the brightness and contrast adjusted image; 93% with the sharpened image; and 94% when the density analysis tool was used. Compared to the unaided eye, the LCD can significantly improve dentists' ability to detect and classify caries. Dentists may be able to find twice as much early dentinal caries requiring restoration (or at least aggressive noninvasive treatment) than previously, while not unnecessarily restoring additional healthy teeth. The LCD enables dentists to obtain more information from dental digital radiography than is possible with the unaided eye, leading to improved patient care.

  15. Orthodontics: computer-aided diagnosis and treatment planning

    NASA Astrophysics Data System (ADS)

    Yi, Yaxing; Li, Zhongke; Wei, Suyuan; Deng, Fanglin; Yao, Sen

    2000-10-01

    The purpose of this article is to introduce the outline of our newly developed computer-aided 3D dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a scanning device and a personal computer as a scanning controller and post processor. The scanning device is composed of a laser beam emitter, two sets of linear CCD cameras and a table which is rotatable by two-degree-of-freedom. The rotating is controlled precisely by a personal computer. The dental cast is projected and scanned with a laser beam. Triangulation is applied to determine the location of each point. Generation of 3D graphics of the dental cast takes approximately 40 minutes. About 170,000 sets of X,Y,Z coordinates are store for one dental cast. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the top surface area of each molar. The advantage of this system is that it facilitates the otherwise complicated and time- consuming mock surgery necessary for treatment planning in orthognathic surgery.

  16. Does the Conners' Continuous Performance Test aid in ADHD diagnosis?

    PubMed

    McGee, R A; Clark, S E; Symons, D K

    2000-10-01

    The performance of clinic-referred children aged 6-11 (N = 100) was examined using the Conners' Continuous Performance Test (CPT) and measures of auditory attention (Auditory Continuous Performance Test; ACPT), phonological awareness, visual processing speed, and visual-motor competence. The Conners' CPT overall index was unrelated to measures of visual processing speed or visual-motor competence. Although the Conners' CPT converged with the ACPT, the latter demonstrated age and order effects. Significant variance in Conners' CPT parameters was predicted by phonological awareness measures, suggesting that Reading Disordered (RD) children could be "false positives" on the Conners' CPT. The Conners' CPT overall index, phonological awareness, and visual-motor measures were submitted to a 2 x 2 MANCOVA (ADHD vs. RD, covarying for age and socioeconomic status): a main effect for RD status was found. Children with ADHD did not have higher Conners' CPT scores than did clinical controls; however, children with Reading Disorders did. Phonological measures distinguished RD children from ADHD children and other clinical controls. ADHD children who failed the Conners' CPT were rated by teachers as more hyperactive. Despite the strengths of the Conners' CPT, its utility for differential diagnosis of ADHD is questioned.

  17. On the convergence of nanotechnology and Big Data analysis for computer-aided diagnosis.

    PubMed

    Rodrigues, Jose F; Paulovich, Fernando V; de Oliveira, Maria Cf; de Oliveira, Osvaldo N

    2016-04-01

    An overview is provided of the challenges involved in building computer-aided diagnosis systems capable of precise medical diagnostics based on integration and interpretation of data from different sources and formats. The availability of massive amounts of data and computational methods associated with the Big Data paradigm has brought hope that such systems may soon be available in routine clinical practices, which is not the case today. We focus on visual and machine learning analysis of medical data acquired with varied nanotech-based techniques and on methods for Big Data infrastructure. Because diagnosis is essentially a classification task, we address the machine learning techniques with supervised and unsupervised classification, making a critical assessment of the progress already made in the medical field and the prospects for the near future. We also advocate that successful computer-aided diagnosis requires a merge of methods and concepts from nanotechnology and Big Data analysis.

  18. Multi-site evaluation of a computer aided detection (CAD) algorithm for small acute intra-cranial hemorrhage and development of a stand-alone CAD system ready for deployment in a clinical environment

    NASA Astrophysics Data System (ADS)

    Deshpande, Ruchi R.; Fernandez, James; Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

    2010-03-01

    Timely detection of Acute Intra-cranial Hemorrhage (AIH) in an emergency environment is essential for the triage of patients suffering from Traumatic Brain Injury. Moreover, the small size of lesions and lack of experience on the reader's part could lead to difficulties in the detection of AIH. A CT based CAD algorithm for the detection of AIH has been developed in order to improve upon the current standard of identification and treatment of AIH. A retrospective analysis of the algorithm has already been carried out with 135 AIH CT studies with 135 matched normal head CT studies from the Los Angeles County General Hospital/ University of Southern California Hospital System (LAC/USC). In the next step, AIH studies have been collected from Walter Reed Army Medical Center, and are currently being processed using the AIH CAD system as part of implementing a multi-site assessment and evaluation of the performance of the algorithm. The sensitivity and specificity numbers from the Walter Reed study will be compared with the numbers from the LAC/USC study to determine if there are differences in the presentation and detection due to the difference in the nature of trauma between the two sites. Simultaneously, a stand-alone system with a user friendly GUI has been developed to facilitate implementation in a clinical setting.

  19. Project CAD as of July 1978: CAD support project, situation in July 1978

    NASA Technical Reports Server (NTRS)

    Boesch, L.; Lang-Lendorff, G.; Rothenberg, R.; Stelzer, V.

    1979-01-01

    The structure of Computer Aided Design (CAD) and the requirements for program developments in past and future are described. The actual standard and the future aims of CAD programs are presented. The developed programs in: (1) civil engineering; (2) mechanical engineering; (3) chemical engineering/shipbuilding; (4) electrical engineering; and (5) general programs are discussed.

  20. Investigating the effects of majority voting on CAD systems: a LIDC case study

    NASA Astrophysics Data System (ADS)

    Carrazza, Miguel; Kennedy, Brendan; Rasin, Alexander; Furst, Jacob; Raicu, Daniela

    2016-03-01

    Computer-Aided Diagnosis (CAD) systems can provide a second opinion for either identifying suspicious regions on a medical image or predicting the degree of malignancy for a detected suspicious region. To develop a predictive model, CAD systems are trained on low-level image features extracted from image data and the class labels acquired through radiologists' interpretations or a gold standard (e.g., a biopsy). While the opinion of an expert radiologist is still an estimate of the answer, the ground truth may be extremely expensive to acquire. In such cases, CAD systems are trained on input data that contains multiple expert opinions per case with the expectation that the aggregate of labels will closely approximate the ground truth. Using multiple labels to solve this problem has its own challenges because of the inherent label uncertainty introduced by the variability in the radiologists' interpretations. Most CAD systems use majority voting (e.g., average, mode) to handle label uncertainty. This paper investigates the effects that majority voting can have on a CAD system by classifying and analyzing different semantic characteristics supplied with the Lung Image Database Consortium (LIDC) dataset. Using a decision tree based iterative predictive model, we show that majority voting with labels that exhibit certain types of skewed distribution can have a significant negative impact on the performance of a CAD system; therefore, alternative strategies for label integration are required when handling multiple interpretations.

  1. Computer-aided diagnosis of interstitial lung disease: a texture feature extraction and classification approach

    NASA Astrophysics Data System (ADS)

    Vargas-Voracek, Rene; McAdams, H. Page; Floyd, Carey E., Jr.

    1998-06-01

    An approach for the classification of normal or abnormal lung parenchyma from selected regions of interest (ROIs) of chest radiographs is presented for computer aided diagnosis of interstitial lung disease (ILD). The proposed approach uses a feed-forward neural network to classify each ROI based on a set of isotropic texture measures obtained from the joint grey level distribution of pairs of pixels separated by a specific distance. Two hundred ROIs, each 64 X 64 pixels in size (11 X 11 mm), were extracted from digitized chest radiographs for testing. Diagnosis performance was evaluated with the leave-one-out method. Classification of independent ROIs achieved a sensitivity of 90% and a specificity of 84% with an area under the receiver operating characteristic curve of 0.85. The diagnosis for each patient was correct for all cases when a `majority vote' criterion for the classification of the corresponding ROIs was applied to issue a normal or ILD patient classification. The proposed approach is a simple, fast, and consistent method for computer aided diagnosis of ILD with a very good performance. Further research will include additional cases, including differential diagnosis among ILD manifestations.

  2. Mammogram CAD, hybrid registration and iconic analysis

    NASA Astrophysics Data System (ADS)

    Boucher, A.; Cloppet, F.; Vincent, N.

    2013-03-01

    This paper aims to develop a computer aided diagnosis (CAD) based on a two-step methodology to register and analyze pairs of temporal mammograms. The concept of "medical file", including all the previous medical information on a patient, enables joint analysis of different acquisitions taken at different times, and the detection of significant modifications. The developed registration method aims to superimpose at best the different anatomical structures of the breast. The registration is designed in order to get rid of deformation undergone by the acquisition process while preserving those due to breast changes indicative of malignancy. In order to reach this goal, a referent image is computed from control points based on anatomical features that are extracted automatically. Then the second image of the couple is realigned on the referent image, using a coarse-to-fine approach according to expert knowledge that allows both rigid and non-rigid transforms. The joint analysis detects the evolution between two images representing the same scene. In order to achieve this, it is important to know the registration error limits in order to adapt the observation scale. The approach used in this paper is based on an image sparse representation. Decomposed in regular patterns, the images are analyzed under a new angle. The evolution detection problem has many practical applications, especially in medical images. The CAD is evaluated using recall and precision of differences in mammograms.

  3. Sinus barotrauma--late diagnosis and treatment with computer-aided endoscopic surgery.

    PubMed

    Larsen, Anders Schermacher; Buchwald, Christian; Vesterhauge, Søren

    2003-02-01

    Sinus barotrauma is usually easy to diagnose, and treatment achieves good results. We present two severe cases where delayed diagnosis caused significant morbidity. The signs and symptoms were atypical and neither the patients themselves, nor the initial examiners recognized that the onset of symptoms coincided with descent in a commercial airliner. CT and MRI scans of the brain were normal, but in both cases showed opafication of the sphenoid sinuses, which lead to the correct diagnosis. Subsequent surgical intervention consisting of endoscopic computer-aided surgery showed blood and petechia in the affected sinuses. This procedure provided immediate relief.

  4. Computer-aided diagnosis of Alzheimer's disease using support vector machines and classification trees

    NASA Astrophysics Data System (ADS)

    Salas-Gonzalez, D.; Górriz, J. M.; Ramírez, J.; López, M.; Álvarez, I.; Segovia, F.; Chaves, R.; Puntonet, C. G.

    2010-05-01

    This paper presents a computer-aided diagnosis technique for improving the accuracy of early diagnosis of Alzheimer-type dementia. The proposed methodology is based on the selection of voxels which present Welch's t-test between both classes, normal and Alzheimer images, greater than a given threshold. The mean and standard deviation of intensity values are calculated for selected voxels. They are chosen as feature vectors for two different classifiers: support vector machines with linear kernel and classification trees. The proposed methodology reaches greater than 95% accuracy in the classification task.

  5. Computer Aided Drafting. Instructor's Guide.

    ERIC Educational Resources Information Center

    Henry, Michael A.

    This guide is intended for use in introducing students to the operation and applications of computer-aided drafting (CAD) systems. The following topics are covered in the individual lessons: understanding CAD (CAD versus traditional manual drafting and care of software and hardware); using the components of a CAD system (primary and other input…

  6. Computer-aided diagnosis workstation and telemedicine network system for chest diagnosis based on multislice CT images

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kakinuma, Ryutaru; Moriyama, Noriyuki

    2009-02-01

    Mass screening based on multi-helical CT images requires a considerable number of images to be read. It is this time-consuming step that makes the use of helical CT for mass screening impractical at present. Moreover, the doctor who diagnoses a medical image is insufficient in Japan. To overcome these problems, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images, a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification and a vertebra body analysis algorithm for quantitative evaluation of osteoporosis likelihood by using helical CT scanner for the lung cancer mass screening. The functions to observe suspicious shadow in detail are provided in computer-aided diagnosis workstation with these screening algorithms. We also have developed the telemedicine network by using Web medical image conference system with the security improvement of images transmission, Biometric fingerprint authentication system and Biometric face authentication system. Biometric face authentication used on site of telemedicine makes "Encryption of file" and "Success in login" effective. As a result, patients' private information is protected. We can share the screen of Web medical image conference system from two or more web conference terminals at the same time. An opinion can be exchanged mutually by using a camera and a microphone that are connected with workstation. Based on these diagnostic assistance methods, we have developed a new computer-aided workstation and a new telemedicine network that can display suspected lesions three-dimensionally in a short time. The results of this study indicate that our radiological information system without film by using computer-aided diagnosis workstation and our telemedicine network system can increase diagnostic speed, diagnostic accuracy and

  7. Some Workplace Effects of CAD and CAM.

    ERIC Educational Resources Information Center

    Ebel, Karl-H.; Ulrich, Erhard

    1987-01-01

    Examines the impact of computer-aided design (CAD) and computer-aided manufacturing (CAM) on employment, work organization, working conditions, job content, training, and industrial relations in several countries. Finds little evidence of negative employment effects since productivity gains are offset by various compensatory factors. (Author/CH)

  8. Train effectively for CAD/D

    SciTech Connect

    Not Available

    1983-04-01

    After failing with an unstructured computer-aided drafting/ design CAD/D program, Bechtel changed to a structured training program. Five considerations are presented here: teach CAD/D to engineers, not engineering to CAD/D experts; keep the program flexible enough to avoid rewriting due to fast technology evolution; pace information delivery; and rote learning of sequences only works if the students have a conceptual model first. On the job training is necessary, and better monitoring systems to test the OJT are needed. One such test is presented.

  9. A feasibility trial of computer-aided diagnosis for enteric lesions in capsule endoscopy

    PubMed Central

    Gan, Tao; Wu, Jun-Chao; Rao, Ni-Ni; Chen, Tao; Liu, Bing

    2008-01-01

    AIM: To investigate and evaluate the feasibility of the computer-aided screening diagnosis for enteric lesions in the capsule endoscopy (CE). METHODS: After developing a series of algorithms for the screening diagnosis of the enteric lesions in CE based on their characteristic colors and contours, the normal and abnormal images obtained from 289 patients were respectively scanned and diagnosed by the CE readers and by the computer-aided screening for the enteric lesions with the image-processed software (IPS). The enteric lesions shown by the images included esoenteritis, mucosal ulcer and erosion, bleeding, space-occupying lesions, angioectasia, diverticula, parasites, etc. The images for the lesions or the suspected lesions confirmed by the CE readers and the computers were collected, and the effectiveness rate of the screening and the number of the scanned images were evaluated, respectively. RESULTS: Compared with the diagnostic results obtained by the CE readers, the total effectiveness rate (sensitivity) in the screening of the commonly-encountered enteric lesions by IPS varied from 42.9% to 91.2%, with a median of 74.2%, though the specificity and the accuracy rates were still low, and the images for the rarely-encountered lesions were difficult to differentiate from the normal images. However, the number of the images screened by IPS was 5000 on average, and only 10%-15% of the original images were left behind. As a result, a large number of normal images were excluded, and the reading time decreased from 5 h to 1 h on average. CONCLUSION: Though the total accuracy and specificity rates by the computer-aided screening for the enteric lesions with IPS are much lower than those by the CE readers, the computer-aided screening diagnosis can exclude a large number of the normal images and confine the enteric lesions to 5000 images on average, which can reduce the workload of the readers in the scanning of the images. This computer-aided screening technique can

  10. Lung cancer differential diagnosis based on the computer assisted radiology: The state of the art

    PubMed Central

    Sprindzuk, M.V.; Kovalev, V.A.; Snezhko, E.V.; Kharuzhyk, S.A.

    2010-01-01

    Summary The concepts of the modern computer-aided diagnosis (CAD), the methods of pulmonary nodules detection and facts derived from the available literature on the pulmonary nodule differential CAD topic are compiled in one source and described in some details. Several issues of the lung cancer epidemiology and an early diagnosis are discussed. The analysis of the performed research shows an evidence that various CAD systems can be successfully applied for chest radiographs, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET). These modalities can serve as a useful tool for a practicing medical professional facing the burden of a routine diagnostic job. PMID:22802764

  11. Lung cancer differential diagnosis based on the computer assisted radiology: The state of the art.

    PubMed

    Sprindzuk, M V; Kovalev, V A; Snezhko, E V; Kharuzhyk, S A

    2010-01-01

    The concepts of the modern computer-aided diagnosis (CAD), the methods of pulmonary nodules detection and facts derived from the available literature on the pulmonary nodule differential CAD topic are compiled in one source and described in some details. Several issues of the lung cancer epidemiology and an early diagnosis are discussed. The analysis of the performed research shows an evidence that various CAD systems can be successfully applied for chest radiographs, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET). These modalities can serve as a useful tool for a practicing medical professional facing the burden of a routine diagnostic job. PMID:22802764

  12. Eye examination for early diagnosis of disseminated tuberculosis in patients with AIDS.

    PubMed

    Heiden, David; Saranchuk, Peter; Keenan, Jeremy D; Ford, Nathan; Lowinger, Alan; Yen, Michael; McCune, Joseph; Rao, Narsing A

    2016-04-01

    Choroidal tuberculosis is present in 5-20% of patients with disseminated tuberculosis, and point-of-care dilated binocular indirect ophthalmoscopy eye examination can provide immediate diagnosis. In geographical areas of high tuberculosis prevalence and in susceptible patients (CD4 counts less than 200 cells per μL) detection of choroidal granulomas should be accepted as evidence of disseminated tuberculosis. With training and proper support, eye screening can be done by HIV/AIDS clinicians, allowing early tuberculosis treatment. In regions with a high burden of tuberculosis, we recommend that eye screening be a standard part of the initial assessment of susceptible patients, including at a minimum all patients with HIV/AIDS with CD4 less than 100 cells per μL with or without eye symptoms, and with or without suspicion of disseminated tuberculosis.

  13. Eye examination for early diagnosis of disseminated tuberculosis in patients with AIDS.

    PubMed

    Heiden, David; Saranchuk, Peter; Keenan, Jeremy D; Ford, Nathan; Lowinger, Alan; Yen, Michael; McCune, Joseph; Rao, Narsing A

    2016-04-01

    Choroidal tuberculosis is present in 5-20% of patients with disseminated tuberculosis, and point-of-care dilated binocular indirect ophthalmoscopy eye examination can provide immediate diagnosis. In geographical areas of high tuberculosis prevalence and in susceptible patients (CD4 counts less than 200 cells per μL) detection of choroidal granulomas should be accepted as evidence of disseminated tuberculosis. With training and proper support, eye screening can be done by HIV/AIDS clinicians, allowing early tuberculosis treatment. In regions with a high burden of tuberculosis, we recommend that eye screening be a standard part of the initial assessment of susceptible patients, including at a minimum all patients with HIV/AIDS with CD4 less than 100 cells per μL with or without eye symptoms, and with or without suspicion of disseminated tuberculosis. PMID:26907735

  14. Cone beam computed tomography aided diagnosis and treatment of endodontic cases: Critical analysis.

    PubMed

    Yılmaz, Funda; Kamburoglu, Kıvanç; Yeta, Naz Yakar; Öztan, Meltem Dartar

    2016-07-28

    Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography (CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, non-diagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information. PMID:27551342

  15. Cone beam computed tomography aided diagnosis and treatment of endodontic cases: Critical analysis

    PubMed Central

    Yılmaz, Funda; Kamburoglu, Kıvanç; Yeta, Naz Yakar; Öztan, Meltem Dartar

    2016-01-01

    Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography (CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, non-diagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information. PMID:27551342

  16. Computer-aided diagnosis of digital mammography images using unsupervised clustering and biclustering techniques

    NASA Astrophysics Data System (ADS)

    Al-Olfe, Mohamed A.; Al-Akwaa, Fadhl M.; Mohamed, Wael A.; Kadah, Yasser M.

    2010-03-01

    A new methodology for computer aided diagnosis in digital mammography using unsupervised classification and classdependent feature selection is presented. This technique considers unlabeled data and provides unsupervised classes that give a better insight into classes and their interrelationships, thus improving the overall effectiveness of the diagnosis. This technique is also extended to utilize biclustering methods, which allow for definition of unsupervised clusters of both pathologies and features. This has potential to provide more flexibility, and hence better diagnostic accuracy, than the commonly used feature selection strategies. The developed methods are applied to diagnose digital mammographic images from the Mammographic Image Analysis Society (MIAS) database and the results confirm the potential for improving the current diagnostic rates.

  17. Computer aided diagnosis for severity assessment of pneumoconiosis using CT images

    NASA Astrophysics Data System (ADS)

    Suzuki, Hidenobu; Matsuhiro, Mikio; Kawata, Yoshiki; Niki, Noboru; Kato, Katsuya; Kishimoto, Takumi; Ashizawa, Kazuto

    2016-03-01

    240,000 participants have a screening for diagnosis of pneumoconiosis every year in Japan. Radiograph is used for staging of severity in pneumoconiosis worldwide. This paper presents a method for quantitative assessment of severity in pneumoconiosis using both size and frequency of lung nodules that detected by thin-section CT images. This method consists of three steps. First, thoracic organs (body, ribs, spine, trachea, bronchi, lungs, heart, and pulmonary blood vessels) are segmented. Second, lung nodules that have radius over 1.5mm are detected. These steps used functions of our developed computer aided detection system of chest CT images. Third, severity in pneumoconiosis is quantified using size and frequency of lung nodules. This method was applied to nine pneumoconiosis patients. The initial results showed that proposed method can assess severity in pneumoconiosis quantitatively. This paper demonstrates effectiveness of our method in diagnosis and prognosis of pneumoconiosis in CT screening.

  18. Computer-Aided Diagnosis and Quantification of Cirrhotic Livers Based on Morphological Analysis and Machine Learning

    PubMed Central

    Chen, Yen-Wei; Luo, Jie; Dong, Chunhua; Han, Xianhua; Tateyama, Tomoko; Furukawa, Akira; Kanasaki, Shuzo

    2013-01-01

    It is widely known that morphological changes of the liver and the spleen occur during the clinical course of chronic liver diseases. In this paper, we proposed a morphological analysis method based on statistical shape models (SSMs) of the liver and spleen for computer-aided diagnosis and quantification of the chronic liver. We constructed not only the liver SSM but also the spleen SSM and a joint SSM of the liver and the spleen for a morphologic analysis of the cirrhotic liver in CT images. The effective modes are selected based on both its accumulation contribution rate and its correlation with doctor's opinions (stage labels). We then learn a mapping function between the selected mode and the stage of chronic liver. The mapping function was used for diagnosis and staging of chronic liver diseases. PMID:24187579

  19. Design-based approach to ethics in computer-aided diagnosis

    NASA Astrophysics Data System (ADS)

    Collmann, Jeff R.; Lin, Jyh-Shyan; Freedman, Matthew T.; Wu, Chris Y.; Hayes, Wendelin S.; Mun, Seong K.

    1996-04-01

    A design-based approach to ethical analysis examines how computer scientists, physicians and patients make and justify choices in designing, using and reacting to computer-aided diagnosis (CADx) systems. The basic hypothesis of this research is that values are embedded in CADx systems during all phases of their development, not just retrospectively imposed on them. This paper concentrates on the work of computer scientists and physicians as they attempt to resolve central technical questions in designing clinically functional CADx systems for lung cancer and breast cancer diagnosis. The work of Lo, Chan, Freedman, Lin, Wu and their colleagues provides the initial data on which this study is based. As these researchers seek to increase the rate of true positive classifications of detected abnormalities in chest radiographs and mammograms, they explore dimensions of the fundamental ethical principal of beneficence. The training of CADx systems demonstrates the key ethical dilemmas inherent in their current design.

  20. Detection of longitudinal ulcer using roughness value for computer aided diagnosis of Crohn's disease

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Kitasaka, Takayuki; Furukawa, Kazuhiro; Watanabe, Osamu; Ando, Takafumi; Goto, Hidemi; Mori, Kensaku

    2011-03-01

    The purpose of this paper is to present a new method to detect ulcers, which is one of the symptoms of Crohn's disease, from CT images. Crohn's disease is an inflammatory disease of the digestive tract. Crohn's disease commonly affects the small intestine. An optical or a capsule endoscope is used for small intestine examinations. However, these endoscopes cannot pass through intestinal stenosis parts in some cases. A CT image based diagnosis allows a physician to observe whole intestine even if intestinal stenosis exists. However, because of the complicated shape of the small and large intestines, understanding of shapes of the intestines and lesion positions are difficult in the CT image based diagnosis. Computer-aided diagnosis system for Crohn's disease having automated lesion detection is required for efficient diagnosis. We propose an automated method to detect ulcers from CT images. Longitudinal ulcers make rough surface of the small and large intestinal wall. The rough surface consists of combination of convex and concave parts on the intestinal wall. We detect convex and concave parts on the intestinal wall by a blob and an inverse-blob structure enhancement filters. A lot of convex and concave parts concentrate on roughed parts. We introduce a roughness value to differentiate convex and concave parts concentrated on the roughed parts from the other on the intestinal wall. The roughness value effectively reduces false positives of ulcer detection. Experimental results showed that the proposed method can detect convex and concave parts on the ulcers.

  1. Survey on computer aided decision support for diagnosis of celiac disease

    PubMed Central

    Hegenbart, Sebastian; Uhl, Andreas; Vécsei, Andreas

    2015-01-01

    Celiac disease (CD) is a complex autoimmune disorder in genetically predisposed individuals of all age groups triggered by the ingestion of food containing gluten. A reliable diagnosis is of high interest in view of embarking on a strict gluten-free diet, which is the CD treatment modality of first choice. The gold standard for diagnosis of CD is currently based on a histological confirmation of serology, using biopsies performed during upper endoscopy. Computer aided decision support is an emerging option in medicine and endoscopy in particular. Such systems could potentially save costs and manpower while simultaneously increasing the safety of the procedure. Research focused on computer-assisted systems in the context of automated diagnosis of CD has started in 2008. Since then, over 40 publications on the topic have appeared. In this context, data from classical flexible endoscopy as well as wireless capsule endoscopy (WCE) and confocal laser endomicrosopy (CLE) has been used. In this survey paper, we try to give a comprehensive overview of the research focused on computer-assisted diagnosis of CD. PMID:25770906

  2. A computer-aided diagnosis system to detect pathologies in temporal subtraction images of chest radiographs

    NASA Astrophysics Data System (ADS)

    Looper, Jared; Harrison, Melanie; Armato, Samuel G.

    2016-03-01

    Radiologists often compare sequential radiographs to identify areas of pathologic change; however, this process is prone to error, as human anatomy can obscure the regions of change, causing the radiologists to overlook pathology. Temporal subtraction (TS) images can provide enhanced visualization of regions of change in sequential radiographs and allow radiologists to better detect areas of change in radiographs. Not all areas of change shown in TS images, however, are actual pathology. The purpose of this study was to create a computer-aided diagnostic (CAD) system that identifies which regions of change are caused by pathology and which are caused by misregistration of the radiographs used to create the TS image. The dataset used in this study contained 120 images with 74 pathologic regions on 54 images outlined by an experienced radiologist. High and low ("light" and "dark") gray-level candidate regions were extracted from the images using gray-level thresholding. Then, sampling techniques were used to address the class imbalance problem between "true" and "false" candidate regions. Next, the datasets of light candidate regions, dark candidate regions, and the combined set of light and dark candidate regions were used as training and testing data for classifiers by using five-fold cross validation. Of the classifiers tested (support vector machines, discriminant analyses, logistic regression, and k-nearest neighbors), the support vector machine on the combined candidates using synthetic minority oversampling technique (SMOTE) performed best with an area under the receiver operating characteristic curve value of 0.85, a sensitivity of 85%, and a specificity of 84%.

  3. The association between combination antiretroviral adherence and AIDS-defining conditions at HIV diagnosis.

    PubMed

    Abara, Winston E; Xu, Junjun; Adekeye, Oluwatoyosi A; Rust, George

    2016-08-01

    Combination antiretroviral therapy (cART) has changed the clinical course of HIV. AIDS-defining conditions (ADC) are suggestive of severe or advanced disease and are a leading cause of HIV-related hospitalizations and death among people living with HIV/AIDS (PLWHA) in the USA. Optimal adherence to cART can mitigate the impact of ADC and disease severity on the health and survivability of PLWHA. The objective of this study was to evaluate the association between ADC at HIV diagnosis and optimal adherence among PLWHA. Using data from the 2008 and 2009 Medicaid data from 29 states, we identified individuals, between 18 and 49 years, recently infected with HIV and with a cART prescription. Frequencies and descriptive statistics were conducted to characterize sample. Univariate and multivariable Poisson regression analyses were employed to evaluate the association optimal cART adherence (defined as ≥ 95% study days covered by cART) and ADC at HIV diagnosis (≥1 ADC) were assessed. Approximately 17% of respondents with ADC at HIV diagnosis reported optimal cART adherence. After adjusting for covariates, respondents with an ADC at HIV diagnosis were less likely to report optimal cART adherence (adjusted prevalence ratio (APR) = 0.64, 95% confidence intervals (CI), 0.54-0.75). Among the covariates, males (APR=1.10, 95% CI, 1.02-1.19) compared to females were significantly more likely to report optimal adherence while younger respondents, 18-29 years (APR=0.67, 95% CI, 0.57-0.77), 30-39 years (APR=0.86, 95% CI, 0.79-0.95) compared to older respondents were significantly less likely to report optimal adherence. PLWHA with ADC at HIV diagnosis are at risk of suboptimal cART adherence. Multiple adherence strategies that include healthcare providers, case managers, and peer navigators should be utilized to improve cART adherence and optimize health outcomes among PLWHA with ADC at HIV diagnosis. Targeted adherence programs and services are required to address

  4. Retinal vessel detection and measurement for computer-aided medical diagnosis.

    PubMed

    Li, Xiaokun; Wee, William G

    2014-02-01

    Since blood vessel detection and characteristic measurement for ocular retinal images is a fundamental problem in computer-aided medical diagnosis, automated algorithms/systems for vessel detection and measurement are always demanded. To support computer-aided diagnosis, an integrated approach/solution for vessel detection and diameter measurement is presented and validated. In the proposed approach, a Dempster-Shafer (D-S)-based edge detector is developed to obtain initial vessel edge information and an accurate vascular map for a retinal image. Then, the appropriate path and the centerline of a vessel of interest are identified automatically through graph search. Once the vessel path has been identified, the diameter of the vessel will be measured accordingly by the algorithm in real time. To achieve more accurate edge detection and diameter measurement, mixed Gaussian-matched filters are designed to refine the initial detection and measures. Other important medical indices of retinal vessels can also be calculated accordingly based on detection and measurement results. The efficiency of the proposed algorithm was validated by the retinal images obtained from different public databases. Experimental results show that the vessel detection rate of the algorithm is 100 % for large vessels and 89.9 % for small vessels, and the error rate on vessel diameter measurement is less than 5 %, which are all well within the acceptable range of deviation among the human graders.

  5. Cystatin C Falsely Underestimated GFR in a Critically Ill Patient with a New Diagnosis of AIDS

    PubMed Central

    Brown, Caitlin S.; Kashani, Kianoush B.; Clain, Jeremy M.

    2016-01-01

    Cystatin C has been suggested to be a more accurate glomerular filtration rate (GFR) surrogate than creatinine in patients with acquired immunodeficiency syndrome (AIDS) because it is unaffected by skeletal muscle mass and dietary influences. However, little is known about the utility of this marker for monitoring medications in the critically ill. We describe the case of a 64-year-old female with opportunistic infections associated with a new diagnosis of AIDS. During her course, she experienced neurologic, cardiac, and respiratory failure; yet her renal function remained preserved as indicated by an eGFR ≥ 120 mL/min and a urine output > 1 mL/kg/hr without diuresis. The patient was treated with nephrotoxic agents; therefore cystatin C was assessed to determine if cachexia was resulting in a falsely low serum creatinine. Cystatin C measured 1.50 mg/L which corresponded to an eGFR of 36 mL/min. Given the >60 mL/min discrepancy, serial 8-hour urine samples were collected and a GFR > 120 mL/min was confirmed. It is unclear why cystatin C was falsely elevated, but we hypothesize that it relates to the proinflammatory state with AIDS, opportunistic infections, and corticosteroids. More research is needed before routine use of cystatin C in this setting can be recommended. PMID:27293926

  6. Spectrum of complicated migraine in children: A common profile in aid to clinical diagnosis

    PubMed Central

    Gupta, Surya N; Gupta, Vikash S; Fields, Dawn M

    2015-01-01

    Complicated migraine encompasses several individual clinical syndromes of migraine. Such a syndrome in children frequently presents with various neurological symptoms in the Emergency Department. An acute presentation in the absence of headache presents a diagnostic challenge. A delay in diagnosis and treatment may have medicolegal implication. To date, there are no reports of a common clinical profile proposed in making a clinical diagnosis for the complicated migraine. In this clinical review, we propose and describe: (1) A common clinical profile in aid to clinical diagnosis for spectrum of complicated migraine; (2) How it can be used in differentiating complicated migraine from migraine without aura, migraine with aura, and seizure; (3) We discuss the status of complicated migraine in the International Headache Society classification 2013; and (4) In addition, a common treatment strategy for the spectrum of migraine has been described. To diagnose complicated migraine clinically, it is imperative to adhere with the proposed profile. This will optimize the use of investigation and will also avoid a legal implication of delay in their management. The proposed common clinical profile is incongruent with the International Headache Society 2013. Future classification should minimize the dissociation from clinically encountered syndromes and coin a single word to address collectively this subtype of migraine with an acute presentation of a common clinical profile. PMID:25664241

  7. Towards a computer-aided diagnosis system for colon motility dysfunctions

    NASA Astrophysics Data System (ADS)

    Glocker, Ben; Buhmann, Sonja; Kirchhoff, Chlodwig; Mussack, Thomas; Reiser, Maximilian; Navab, Nassir

    2007-03-01

    Colon motility disorders are a very common problem. A precise diagnosis with current methods is almost unachievable. This makes it extremely difficult for the clinical experts to decide for the right intervention such as colon resection. The use of cine MRI for visualizing the colon motility is a very promising technique. In addition, if image segmentation and qualitative motion analysis provide the necessary tools, it could provide the appropriate diagnostic solution. In this work we defined necessary steps in the image processing workflow to gain valuable measurements for a computer aided diagnosis of colon motility disorders. For each step, we developed methods to deal with the dynamic image data. There is need for compensating the breathing motion since no respiratory gating could be used. We segment the colon using a graph cuts approach in 2D and 3D for further analysis and visualization. The analysis of the large bowel motility is done by tracking the extension of the colon during a propagating peristaltic wave. The main objective of this work is to extract a motion model to define a clinical index that can be used in diagnosis of large bowel motility dysfunction. We aim at the classification and localization of such pathologies.

  8. Computer-aided diagnosis of breast cancer based on fine needle biopsy microscopic images.

    PubMed

    Kowal, Marek; Filipczuk, Paweł; Obuchowicz, Andrzej; Korbicz, Józef; Monczak, Roman

    2013-10-01

    Prompt and widely available diagnostics of breast cancer is crucial for the prognosis of patients. One of the diagnostic methods is the analysis of cytological material from the breast. This examination requires extensive knowledge and experience of the cytologist. Computer-aided diagnosis can speed up the diagnostic process and allow for large-scale screening. One of the largest challenges in the automatic analysis of cytological images is the segmentation of nuclei. In this study, four different clustering algorithms are tested and compared in the task of fast nuclei segmentation. K-means, fuzzy C-means, competitive learning neural networks and Gaussian mixture models were incorporated for clustering in the color space along with adaptive thresholding in grayscale. These methods were applied in a medical decision support system for breast cancer diagnosis, where the cases were classified as either benign or malignant. In the segmented nuclei, 42 morphological, topological and texture features were extracted. Then, these features were used in a classification procedure with three different classifiers. The system was tested for classification accuracy by means of microscopic images of fine needle breast biopsies. In cooperation with the Regional Hospital in Zielona Góra, 500 real case medical images from 50 patients were collected. The acquired classification accuracy was approximately 96-100%, which is very promising and shows that the presented method ensures accurate and objective data acquisition that could be used to facilitate breast cancer diagnosis. PMID:24034748

  9. An Evaluation of Internet-Based CAD Collaboration Tools

    ERIC Educational Resources Information Center

    Smith, Shana Shiang-Fong

    2004-01-01

    Due to the now widespread use of the Internet, most companies now require computer aided design (CAD) tools that support distributed collaborative design on the Internet. Such CAD tools should enable designers to share product models, as well as related data, from geographically distant locations. However, integrated collaborative design…

  10. An Instructional Method for the AutoCAD Modeling Environment.

    ERIC Educational Resources Information Center

    Mohler, James L.

    1997-01-01

    Presents a command organizer for AutoCAD to aid new uses in operating within the 3-D modeling environment. Addresses analyzing the problem, visualization skills, nonlinear tools, a static view of a dynamic model, the AutoCAD organizer, environment attributes, and control of the environment. Contains 11 references. (JRH)

  11. An application protocol for CAD to CAD transfer of electronic information

    NASA Technical Reports Server (NTRS)

    Azu, Charles C., Jr.

    1993-01-01

    The exchange of Computer Aided Design (CAD) information between dissimilar CAD systems is a problem. This is especially true for transferring electronics CAD information such as multi-chip module (MCM), hybrid microcircuit assembly (HMA), and printed circuit board (PCB) designs. Currently, there exists several neutral data formats for transferring electronics CAD information. These include IGES, EDIF, and DXF formats. All these formats have limitations for use in exchanging electronic data. In an attempt to overcome these limitations, the Navy's MicroCIM program implemented a project to transfer hybrid microcircuit design information between dissimilar CAD systems. The IGES (Initial Graphics Exchange Specification) format is used since it is well established within the CAD industry. The goal of the project is to have a complete transfer of microelectronic CAD information, using IGES, without any data loss. An Application Protocol (AP) is being developed to specify how hybrid microcircuit CAD information will be represented by IGES entity constructs. The AP defines which IGES data items are appropriate for describing HMA geometry, connectivity, and processing as well as HMA material characteristics.

  12. Dynamic MRI-based computer aided diagnostic systems for early detection of kidney transplant rejection: A survey

    NASA Astrophysics Data System (ADS)

    Mostapha, Mahmoud; Khalifa, Fahmi; Alansary, Amir; Soliman, Ahmed; Gimel'farb, Georgy; El-Baz, Ayman

    2013-10-01

    Early detection of renal transplant rejection is important to implement appropriate medical and immune therapy in patients with transplanted kidneys. In literature, a large number of computer-aided diagnostic (CAD) systems using different image modalities, such as ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), and radionuclide imaging, have been proposed for early detection of kidney diseases. A typical CAD system for kidney diagnosis consists of a set of processing steps including: motion correction, segmentation of the kidney and/or its internal structures (e.g., cortex, medulla), construction of agent kinetic curves, functional parameter estimation, diagnosis, and assessment of the kidney status. In this paper, we survey the current state-of-the-art CAD systems that have been developed for kidney disease diagnosis using dynamic MRI. In addition, the paper addresses several challenges that researchers face in developing efficient, fast and reliable CAD systems for the early detection of kidney diseases.

  13. Computer aided diagnosis of osteoporosis using multi-slice CT images

    NASA Astrophysics Data System (ADS)

    Takahashi, Eiji; Saita, Shinsuke; Kawata, Yoshiki; Niki, Noboru; Ito, Masako; Nishitani, Hiromu; Moriyama, Noriyuki

    2010-03-01

    The patients of osteoporosis comprised about 11 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. The development of Multislice CT technology made it possible to perform the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer screening which may lead to its early detection. We develop an automatic extraction algorithm of vertebra, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the computer aided diagnosis of osteoporosis.

  14. Computer aided diagnosis of schizophrenia on resting state fMRI data by ensembles of ELM.

    PubMed

    Chyzhyk, Darya; Savio, Alexandre; Graña, Manuel

    2015-08-01

    Resting state functional Magnetic Resonance Imaging (rs-fMRI) is increasingly used for the identification of image biomarkers of brain diseases or psychiatric conditions such as schizophrenia. This paper deals with the application of ensembles of Extreme Learning Machines (ELM) to build Computer Aided Diagnosis systems on the basis of features extracted from the activity measures computed over rs-fMRI data. The power of ELM to provide quick but near optimal solutions to the training of Single Layer Feedforward Networks (SLFN) allows extensive exploration of discriminative power of feature spaces in affordable time with off-the-shelf computational resources. Exploration is performed in this paper by an evolutionary search approach that has found functional activity map features allowing to achieve quite successful classification experiments, providing biologically plausible voxel-site localizations.

  15. A Case Study in CAD Design Automation

    ERIC Educational Resources Information Center

    Lowe, Andrew G.; Hartman, Nathan W.

    2011-01-01

    Computer-aided design (CAD) software and other product life-cycle management (PLM) tools have become ubiquitous in industry during the past 20 years. Over this time they have continuously evolved, becoming programs with enormous capabilities, but the companies that use them have not evolved their design practices at the same rate. Due to the…

  16. Mechanical Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    McClain, Gerald R.

    This instructor's manual contains 13 units of instruction for a course on mechanical drafting with options for using computer-aided drafting (CAD). Each unit includes some or all of the following basic components of a unit of instruction: objective sheet, suggested activities for the teacher, assignment sheets and answers to assignment sheets,…

  17. Computer-aided diagnosis of pneumonia in patients with chronic obstructive pulmonary disease

    PubMed Central

    Sánchez Morillo, Daniel; León Jiménez, Antonio; Moreno, Sonia Astorga

    2013-01-01

    Background Early diagnosis of pneumonia and discrimination between this disease and chronic obstructive pulmonary disease (COPD) exacerbations in patients with COPD are crucial for optimal clinical management and treatment. Objectives To examine the use of computerized analysis of respiratory sounds, a hybrid system based on principal component analysis (PCA) and probabilistic neural networks (PNNs), to aid the detection of coexisting pneumonia in patients with COPD. Methods and materials A convenience sample of 58 patients with COPD (25 patients hospitalized for community-acquired pneumonia and 33 owing to acute exacerbation of COPD) was studied. Auscultations were performed by the patients themselves on their suprasternal notch. Short-time Fourier transform analysis was used to extract features from the recorded respiratory sounds, PCA was selected for dimensionality reduction and a PNN was trained as classifier. 10-Fold cross-validation and receiver operating characteristic curve analysis were used to estimate the system performance. Results Based on the cross-validation results, a sensitivity and a specificity of 72% and 81.8%, respectively, were achieved in validation data. The operating point was selected to maximize the specificity and sensitivity pair in the training set. Discussion The results strongly suggest that electronic self-auscultation at a single location (suprasternal notch) can support diagnosis of pneumonia in patients with COPD. Conclusions A simple, cost-effective method has been proposed to aid decision-making in areas with no radiological facilities available and in resource-constrained settings, and could have a great diagnostic impact on telemedicine applications. PMID:23396513

  18. Evaluation of Computer-aided Diagnosis on a Large Clinical Full-Field Digital Mammographic Dataset

    PubMed Central

    Li, Hui; Giger, Maryellen L.; Yuan, Yading; Chen, Weijie; Horsch, Karla; Lan, Li; Jamieson, Andrew R.; Sennett, Charlene A.; Jansen, Sanaz A.

    2008-01-01

    Rationale and Objectives: To convert and optimize our previously developed computerized analysis methods for use with images from full-field digital mammography (FFDM) for breast mass classification in order to aid in the diagnosis of breast cancer. Materials and Methods: An institutional review board approved protocol was obtained, with waiver of consent for retrospective use of mammograms and pathology data. Seven hundreds and thirty-nine full-field digital mammographic images, which contained 287 biopsy-proven breast mass lesions, of which 148 lesions were malignant and 139 lesions were benign, were retrospectively collected. Lesion margins were delineated by an expert breast radiologist and were used as the truth for lesion-segmentation evaluation. Our computerized image analysis method consisted of several steps: 1) identified lesions were automatically extracted from the parenchymal background using computerized segmentation methods; 2) a set of image characteristics (mathematical descriptors) were automatically extracted from image data of the lesions and surrounding tissues; and 3) selected features were merged into an estimate of the probability of malignancy using a Bayesian artificial neural network classifier. Performance of the analyses was evaluated at various stages of the conversion using receiver operating characteristic (ROC) analysis. Results: An AUC value of 0.81 was obtained in the task of distinguishing between malignant and benign mass lesions in a round-robin by case evaluation on the entire FFDM dataset. We failed to show a statistically significant difference (P value=0.83) as compared with results from our previous study in which the computerized classification was performed on digitized screen-film mammograms (SFMD). Conclusion: Our computerized analysis methods developed on digitized screen-film mammography can be converted for use with FFDM. Results show that the computerized analysis methods for the diagnosis of breast mass lesions on

  19. CAD-CAE in Electrical Machines and Drives Teaching.

    ERIC Educational Resources Information Center

    Belmans, R.; Geysen, W.

    1988-01-01

    Describes the use of computer-aided design (CAD) techniques in teaching the design of electrical motors. Approaches described include three technical viewpoints, such as electromagnetics, thermal, and mechanical aspects. Provides three diagrams, a table, and conclusions. (YP)

  20. Overview of NASA MSFC IEC Multi-CAD Collaboration Capability

    NASA Technical Reports Server (NTRS)

    Moushon, Brian; McDuffee, Patrick

    2005-01-01

    This viewgraph presentation provides an overview of a Design and Data Management System (DDMS) for Computer Aided Design (CAD) collaboration in order to support the Integrated Engineering Capability (IEC) at Marshall Space Flight Center (MSFC).

  1. CD4 quantification based on magneto ELISA for AIDS diagnosis in low resource settings.

    PubMed

    Carinelli, S; Xufré, C; Alegret, S; Martí, M; Pividori, M I

    2016-11-01

    The Acquired Immune Deficiency Syndrome (AIDS) affects the life of millions of people around the world. Although rapid and low cost screening tests are widely available for the diagnosis of HIV infection, the count of CD4+ T lymphocytes remains a drawback in the areas mostly affected by the HIV, being this control imperative for assessing the deterioration of the immunological system and the progression towards AIDS, when the counting of cells falls down 200cellsμL(-1). This paper describes a high-throughput, simple and rapid method for CD4+ T lymphocytes quantification, directly in whole blood, based on a magneto ELISA. The CD4 cells are separated and preconcentrated from whole blood in magnetic particles, and labeled with an enzyme for the optical readout performed with a standard microplate reader. The magneto ELISA is able to reach the whole CD4 counting range of medical interest, being the limit of detection as low as 50 CD4+ cells per μL of whole blood, without any pretreatment. This method is a highly suitable alternative diagnostic tool for the expensive flow cytometry at the community and primary care level, providing a sensitive method but by using instrumentation widely available in low-resource settings laboratories and requiring low-maintenance, as is the case of a microplate reader operated by filters.

  2. Electrochemical magneto-actuated biosensor for CD4 count in AIDS diagnosis and monitoring.

    PubMed

    Carinelli, S; Xufré Ballesteros, C; Martí, M; Alegret, S; Pividori, M I

    2015-12-15

    The counting of CD4(+) T lymphocytes is a clinical parameter used for AIDS diagnosis and follow-up. As this disease is particularly prevalent in developing countries, simple and affordable CD4 cell counting methods are urgently needed in resource-limited settings. This paper describes an electrochemical magneto-actuated biosensor for CD4 count in whole blood. The CD4(+) T lymphocytes were isolated, preconcentrated and labeled from 100 μL of whole blood by immunomagnetic separation with magnetic particles modified with antiCD3 antibodies. The captured cells were labeled with a biotinylated antiCD4 antibody, followed by the reaction with the electrochemical reporter streptavidin-peroxidase conjugate. The limit of detection for the CD4 counting magneto-actuated biosensor in whole blood was as low as 44 cells μL(-1) while the logistic range was found to be from 89 to 912 cells μL(-1), which spans the whole medical interest range for CD4 counts in AIDS patients. The electrochemical detection together with the immunomagnetic separation confers high sensitivity, resulting in a rapid, inexpensive, robust, user-friendly method for CD4 counting. This approach is a promising alternative for the costly standard flow cytometry and suitable as diagnostic tool at decentralized practitioner sites in low resource settings, especially in less developed countries.

  3. CD4 quantification based on magneto ELISA for AIDS diagnosis in low resource settings.

    PubMed

    Carinelli, S; Xufré, C; Alegret, S; Martí, M; Pividori, M I

    2016-11-01

    The Acquired Immune Deficiency Syndrome (AIDS) affects the life of millions of people around the world. Although rapid and low cost screening tests are widely available for the diagnosis of HIV infection, the count of CD4+ T lymphocytes remains a drawback in the areas mostly affected by the HIV, being this control imperative for assessing the deterioration of the immunological system and the progression towards AIDS, when the counting of cells falls down 200cellsμL(-1). This paper describes a high-throughput, simple and rapid method for CD4+ T lymphocytes quantification, directly in whole blood, based on a magneto ELISA. The CD4 cells are separated and preconcentrated from whole blood in magnetic particles, and labeled with an enzyme for the optical readout performed with a standard microplate reader. The magneto ELISA is able to reach the whole CD4 counting range of medical interest, being the limit of detection as low as 50 CD4+ cells per μL of whole blood, without any pretreatment. This method is a highly suitable alternative diagnostic tool for the expensive flow cytometry at the community and primary care level, providing a sensitive method but by using instrumentation widely available in low-resource settings laboratories and requiring low-maintenance, as is the case of a microplate reader operated by filters. PMID:27591585

  4. Electrochemical magneto-actuated biosensor for CD4 count in AIDS diagnosis and monitoring.

    PubMed

    Carinelli, S; Xufré Ballesteros, C; Martí, M; Alegret, S; Pividori, M I

    2015-12-15

    The counting of CD4(+) T lymphocytes is a clinical parameter used for AIDS diagnosis and follow-up. As this disease is particularly prevalent in developing countries, simple and affordable CD4 cell counting methods are urgently needed in resource-limited settings. This paper describes an electrochemical magneto-actuated biosensor for CD4 count in whole blood. The CD4(+) T lymphocytes were isolated, preconcentrated and labeled from 100 μL of whole blood by immunomagnetic separation with magnetic particles modified with antiCD3 antibodies. The captured cells were labeled with a biotinylated antiCD4 antibody, followed by the reaction with the electrochemical reporter streptavidin-peroxidase conjugate. The limit of detection for the CD4 counting magneto-actuated biosensor in whole blood was as low as 44 cells μL(-1) while the logistic range was found to be from 89 to 912 cells μL(-1), which spans the whole medical interest range for CD4 counts in AIDS patients. The electrochemical detection together with the immunomagnetic separation confers high sensitivity, resulting in a rapid, inexpensive, robust, user-friendly method for CD4 counting. This approach is a promising alternative for the costly standard flow cytometry and suitable as diagnostic tool at decentralized practitioner sites in low resource settings, especially in less developed countries. PMID:26264263

  5. Computer-aided diagnosis of leukoencephalopathy in children treated for acute lymphoblastic leukemia

    NASA Astrophysics Data System (ADS)

    Glass, John O.; Li, Chin-Shang; Helton, Kathleen J.; Reddick, Wilburn E.

    2005-04-01

    The purpose of this study was to use objective quantitative MR imaging methods to develop a computer-aided diagnosis tool to differentiate white matter (WM) hyperintensities as either leukoencephalopathy (LE) or normal maturational processes in children treated for acute lymphoblastic leukemia with intravenous high dose methotrexate. A combined imaging set consisting of T1, T2, PD, and FLAIR MR images and WM, gray matter, and cerebrospinal fluid a priori maps from a spatially normalized atlas were analyzed with a neural network segmentation based on a Kohonen Self-Organizing Map. Segmented regions were manually classified to identify the most hyperintense WM region and the normal appearing genu region. Signal intensity differences normalized to the genu within each examination were generated for two time points in 203 children. An unsupervised hierarchical clustering algorithm with the agglomeration method of McQuitty was used to divide data from the first examination into normal appearing or LE groups. A C-support vector machine (C-SVM) was then trained on the first examination data and used to classify the data from the second examination. The overall accuracy of the computer-aided detection tool was 83.5% (299/358) with sensitivity to normal WM of 86.9% (199/229) and specificity to LE of 77.5% (100/129) when compared to the readings of two expert observers. These results suggest that subtle therapy-induced leukoencephalopathy can be objectively and reproducibly detected in children treated for cancer using this computer-aided detection approach based on relative differences in quantitative signal intensity measures normalized within each examination.

  6. Histoplasma capsulatum var. duboisii infection in a patient with AIDS: rapid diagnosis using polymerase chain reaction-sequencing.

    PubMed

    Pellaton, Cyril; Cavassini, Matthias; Jaton-Ogay, Katia; Carron, Pierre-Nicolas; Christen-Zaech, Stéphanie; Calandra, Thierry; Bille, Jacques; Hauser, Philippe M

    2009-05-01

    We describe an original case of disseminated infection with Histoplasma capsulatum (Hc) var. duboisii in an African patient with AIDS who migrated to Switzerland. The diagnosis of histoplasmosis was suggested using direct examination of tissues and confirmed in 24 h with a panfungal polymerase chain reaction assay. The variety duboisii of Hc was established using DNA sequencing of the polymorphic genomic region OLE. Molecular tools allow diagnosis of histoplasmosis in 24 h, which is drastically shorter than culture procedures. PMID:19304436

  7. Substance abuse treatment in persons with HIV/AIDS: challenges in managing triple diagnosis.

    PubMed

    Durvasula, Ramani; Miller, Theodore R

    2014-01-01

    Clinical management of HIV must account for the "triple diagnosis" of HIV, psychiatric diagnosis, and substance use disorders and requires integrated treatment services that focus beyond just mitigation of substance use and psychiatric and medical symptoms but also address other health behaviors. Because clinical management of HIV/AIDS has shifted significantly with the advent of highly active antiretroviral therapies (HAART) in the mid 1990s, a literature review focusing on literature published since 2000, and using relevant key words was conducted using a wide range of literature search databases. This literature review was complemented by studies to expand on specific treatment modalities for which there was a dearth of literature addressing HIV infected cohorts and to provide discussion of issues around substance abuse treatment as an HIV prevention tool. Existing models of substance abuse treatment including cognitive behavioral therapy and motivational interviewing have proven to be useful for enhancing adherence and reducing substance use in outpatient populations, while methadone maintenance and directly observed treatment have been useful with specific subgroups of users. Contextualization of services heightens the likelihood of successful outcomes and relapse prevention.

  8. Computer aided diagnosis and treatment planning for developmental dysplasia of the hip

    NASA Astrophysics Data System (ADS)

    Li, Bin; Lu, Hongbing; Cai, Wenli; Li, Xiang; Meng, Jie; Liang, Zhengrong

    2005-04-01

    The developmental dysplasia of the hip (DDH) is a congenital malformation affecting the proximal femurs and acetabulum that are subluxatable, dislocatable, and dislocated. Early diagnosis and treatment is important because failure to diagnose and improper treatment can result in significant morbidity. In this paper, we designed and implemented a computer aided system for the diagnosis and treatment planning of this disease. With the design, the patient received CT (computed tomography) or MRI (magnetic resonance imaging) scan first. A mixture-based PV partial-volume algorithm was applied to perform bone segmentation on CT image, followed by three-dimensional (3D) reconstruction and display of the segmented image, demonstrating the special relationship between the acetabulum and femurs for visual judgment. Several standard procedures, such as Salter procedure, Pemberton procedure and Femoral Shortening osteotomy, were simulated on the screen to rehearse a virtual treatment plan. Quantitative measurement of Acetabular Index (AI) and Femoral Neck Anteversion (FNA) were performed on the 3D image for evaluation of DDH and treatment plans. PC graphics-card GPU architecture was exploited to accelerate the 3D rendering and geometric manipulation. The prototype system was implemented on PC/Windows environment and is currently under clinical trial on patient datasets.

  9. Computer-aided diagnosis of mammographic masses using scalable image retrieval.

    PubMed

    Jiang, Menglin; Zhang, Shaoting; Li, Hongsheng; Metaxas, Dimitris N

    2015-02-01

    Computer-aided diagnosis of masses in mammograms is important to the prevention of breast cancer. Many approaches tackle this problem through content-based image retrieval techniques. However, most of them fall short of scalability in the retrieval stage, and their diagnostic accuracy is, therefore, restricted. To overcome this drawback, we propose a scalable method for retrieval and diagnosis of mammographic masses. Specifically, for a query mammographic region of interest (ROI), scale-invariant feature transform (SIFT) features are extracted and searched in a vocabulary tree, which stores all the quantized features of previously diagnosed mammographic ROIs. In addition, to fully exert the discriminative power of SIFT features, contextual information in the vocabulary tree is employed to refine the weights of tree nodes. The retrieved ROIs are then used to determine whether the query ROI contains a mass. The presented method has excellent scalability due to the low spatial-temporal cost of vocabulary tree. Extensive experiments are conducted on a large dataset of 11 553 ROIs extracted from the digital database for screening mammography, which demonstrate the accuracy and scalability of our approach. PMID:25361497

  10. Computer-Aided Diagnosis of Skin Lesions Using Conventional Digital Photography: A Reliability and Feasibility Study

    PubMed Central

    Chang, Wen-Yu; Huang, Adam; Yang, Chung-Yi; Lee, Chien-Hung; Chen, Yin-Chun; Wu, Tian-Yau; Chen, Gwo-Shing

    2013-01-01

    Background Computer-aided diagnosis (CADx) software that provides a second opinion has been widely used to assist physicians with various tasks. In dermatology, however, CADx has been mostly limited to melanoma or melanocytic skin cancer diagnosis. The frequency of non-melanocytic skin cancers and the accessibility of regular digital macrographs have raised interest in developing CADx for broader applications. Objectives To investigate the feasibility of using CADx to diagnose both melanocytic and non-melanocytic skin lesions based on conventional digital photographic images. Methods This study was approved by an institutional review board, and the requirement to obtain informed consent was waived. In total, 769 conventional photographs of melanocytic and non-melanocytic skin lesions were retrospectively reviewed and used to develop a CADx system. Conventional and new color-related image features were developed to classify the lesions as benign or malignant using support vector machines (SVMs). The performance of CADx was compared with that of dermatologists. Results The clinicians' overall sensitivity, specificity, and accuracy were 83.33%, 85.88%, and 85.31%, respectively. New color correlation and principal component analysis (PCA) features improved the classification ability of the baseline CADx (p = 0.001). The estimated area under the receiver operating characteristic (ROC) curve (Az) of the proposed CADx system was 0.949, with a sensitivity and specificity of 85.63% and 87.65%, respectively, and a maximum accuracy of 90.64%. Conclusions We have developed an effective CADx system to classify both melanocytic and non-melanocytic skin lesions using conventional digital macrographs. The system's performance was similar to that of dermatologists at our institute. Through improved feature extraction and SVM analysis, we found that conventional digital macrographs were feasible for providing useful information for CADx applications. The new color

  11. Use of genetic algorithms for computer-aided diagnosis of breast cancers from image features

    NASA Astrophysics Data System (ADS)

    Floyd, Carey E., Jr.; Tourassi, Georgia D.; Baker, Jay A.

    1996-04-01

    In this investigation we explore genetic algorithms as a technique to train the weights in a feed forward neural network designed to predict breast cancer based on mammographic findings and patient history. Mammograms were obtained from 206 patients who obtained breast biopsies. Mammographic findings were recorded by radiologists for each patient. In addition, the outcome of the biopsy was recorded. Of the 206 cases, 73 were malignant while 133 were benign at the time of biopsy. A genetic algorithm (GA) was developed to adjust the weights of an artificial neural network (ANN) so that the ANN would output the outcome of the biopsy when the mammographic findings were given as inputs. The GA is a technique for function optimization that reflects biological genetic evolution. The ANN was a fully connected feed- forward network using a sigmoid activation with 11 inputs, one hidden layer with 10 nodes, and one output node (benign/malignant). The GA approach allows much flexibility in selecting the function to be optimized. In this work both mean-squared error (MSE) and receiver operating characteristic (ROC) curve area (Az) were explored as optimization criteria. The system was trained using a bootstrap sampling. Optimizing for the two criteria result in different solutions. The 'best' solution was obtained by minimizing a linear combination of MSE and (1-Az). ROC areas were 0.82 plus or minus 0.07, somewhat less than those obtained using backpropagation for ANN training: 0.90 plus or minus 0.05. This is the first description of a genetic algorithm for breast cancer diagnosis. The novel advantage of this technique is the ability to optimize the system for maximizing ROC area rather than minimizing mean squared error. A new technique for computer-aided diagnosis of breast cancer has been explored. The flexibility of the GA approach allows optimization of cost functions that have relevance to breast cancer prediction.

  12. A tool for computer-aided diagnosis of retinopathy of prematurity

    NASA Astrophysics Data System (ADS)

    Zhao, Zheen; Wallace, David K.; Freedman, Sharon F.; Aylward, Stephen R.

    2008-03-01

    In this paper we present improvements to a software application, named ROPtool, that aids in the timely and accurate detection and diagnosis of retinopathy of prematurity (ROP). ROP occurs in 68% of infants less than 1251 grams at birth, and it is a leading cause of blindness for prematurely born infants. The standard of care for its diagnosis is the subjective assessment of retinal vessel dilation and tortuosity. There is significant inter-observer variation in those assessments. ROPtool analyzes retinal images, extracts user-selected blood vessels from those images, and quantifies the tortuosity of those vessels. The presence of ROP is then gauged by comparing the tortuosity of an infant's retinal vessels with measures made from a clinical-standard image of severely tortuous retinal vessels. The presence of such tortuous retinal vessels is referred to as 'plus disease'. In this paper, a novel metric of tortuosity is proposed. From the ophthalmologist's point of view, the new metric is an improvement from our previously published algorithm, since it uses smooth curves instead of straight lines to simulate 'normal vessels'. Another advantage of the new ROPtool is that minimal user interactions are required. ROPtool utilizes a ridge traversal algorithm to extract retinal vessels. The algorithm reconstructs connectivity along a vessel automatically. This paper supports its claims by reporting ROC curves from a pilot study involving 20 retinal images. The areas under two ROC curves, from two experts in ROP, using the new metric to diagnose 'tortuosity sufficient for plus disease', varied from 0.86 to 0.91.

  13. Computer-aided diagnosis scheme for histological classification of clustered microcalcifications on magnification mammograms.

    PubMed

    Nakayama, Ryohei; Uchiyama, Yoshikazu; Watanabe, Ryoji; Katsuragawa, Shigehiko; Namba, Kiyoshi; Doi, Kunio

    2004-04-01

    The histological classification of clustered microcalcifications on mammograms can be difficult, and thus often require biopsy or follow-up. Our purpose in this study was to develop a computer-aided diagnosis scheme for identifying the histological classification of clustered microcalcifications on magnification mammograms in order to assist the radiologists' interpretation as a "second opinion." Our database consisted of 58 magnification mammograms, which included 35 malignant clustered microcalcifications (9 invasive carcinomas, 12 noninvasive carcinomas of the comedo type, and 14 noninvasive carcinomas of the noncomedo type) and 23 benign clustered microcalcifications (17 mastopathies and 6 fibroadenomas). The histological classifications of all clustered microcalcifications were proved by pathologic diagnosis. The clustered microcalcifications were first segmented by use of a novel filter bank and a thresholding technique. Five objective features on clustered microcalcifications were determined by taking into account subjective features that experienced the radiologists commonly use to identify possible histological classifications. The Bayes decision rule with five objective features was employed for distinguishing between five histological classifications. The classification accuracies for distinguishing between three malignant histological classifications were 77.8% (7/9) for invasive carcinoma, 75.0% (9/12) for noninvasive carcinoma of the comedo type, and 92.9% (13/14) for noninvasive carcinoma of the noncomedo type. The classification accuracies for distinguishing between two benign histological classifications were 94.1% (16/17) for mastopathy, and 100.0% (6/6) for fibroadenoma. This computerized method would be useful in assisting radiologists in their assessments of clustered microcalcifications. PMID:15124996

  14. CAD-CAM at Bendix Kansas city: the BICAM system

    SciTech Connect

    Witte, D.R.

    1983-04-01

    Bendix Kansas City Division (BEKC) has been involved in Computer Aided Manufacturing (CAM) technology since the late 1950's when the numerical control (N/C) analysts installed computers to aid in N/C tape preparation for numerically controlled machines. Computer Aided Design (CAD) technology was introduced in 1976, when a number of 2D turnkey drafting stations were procured for printed wiring board (PWB) drawing definition and maintenance. In June, 1980, CAD-CAM Operations was formed to incorporate an integrated CAD-CAM capability into Bendix operations. In March 1982, a ninth division was added to the existing eight divisions at Bendix. Computer Integrated Manufacturing (CIM) is a small organization, reporting directly to the general manager, who has responsibility to coordinate the overall integration of computer aided systems at Bendix. As a long range plan, CIM has adopted a National Bureau of Standards (NBS) architecture titled Factory of the Future. Conceptually, the Bendix CAD-CAM system has a centrally located data base which can be accessed by both CAD and CAM tools, processes, and personnel thus forming an integrated Computer Aided Engineering (CAE) System. This is a key requirement of the Bendix CAD-CAM system that will be presented in more detail.

  15. CAD in the processing plant environment or managing the CAD revolution

    SciTech Connect

    Woolbert, M.A.; Bennett, R.S.; Haring, W.I.

    1985-10-01

    The author presents a case report on the use of a Computer Aided Design/Computer Aided Drafting (CAD) system. Illustrated is a four-work station system, in addition to which there are two 70 megabyte disk drives, a check plotter and a 24-inch wide electrostatic plotter, a 300 megabyte disk for on-line storage, a tape drive for archive and backup, and a 1-megabyte network process server. It is a distributed logic system. The author states that the CAD system both inexpensive enough and powerful enough for the plant environment is relatively new on the market, made possible by the advent of super microcomputers. Also discussed is the impact the CAD system has had on productivity.

  16. Computer aided production engineering

    SciTech Connect

    Not Available

    1986-01-01

    This book presents the following contents: CIM in avionics; computer analysis of product designs for robot assembly; a simulation decision mould for manpower forecast and its application; development of flexible manufacturing system; advances in microcomputer applications in CAD/CAM; an automated interface between CAD and process planning; CAM and computer vision; low friction pneumatic actuators for accurate robot control; robot assembly of printed circuit boards; information systems design for computer integrated manufacture; and a CAD engineering language to aid manufacture.

  17. Quantitative evaluation of photic driving response for computer-aided diagnosis

    NASA Astrophysics Data System (ADS)

    Fukami, Tadanori; Ishikawa, Fumito; Ishikawa, Bunnoshin; Saito, Yoichi

    2008-12-01

    The aim of our research is the quantification of the photic driving response, a routine electroencephalogram (EEG) examination, for computer-aided diagnosis. It is well known that the EEG responds not only to the fundamental frequency but also to all sub and higher harmonics of a stimulus. In this study, we propose a method for detecting and evaluating responses in screening data for individuals. This method consists of two comparisons based on statistical tests. One is an intraindividual comparison between the EEG at rest and the photic stimulation (PS) response reflecting enhancement and suppression by PS, and the other is a comparison between data from an individual and a distribution of normals reflecting the position of the individual's data in the distribution of normals in the normal database. These tests were evaluated using the Z-value based on the Mann-Whitney U-test. We measured EEGs from 130 normal subjects and 30 patients with any of schizophrenia, dementia and epilepsy. Normal data were divided into two groups, the first consisting of 100 data for database construction and the second of 30 data for test data. Using our method, a prominent statistical peak of the Z-value was recognized even if the harmonics and alpha band overlapped. Moreover, we found a statistical difference between patients and the normal database at diagnostically helpful frequencies such as subharmonics, the fundamental wave, higher harmonics and the alpha frequency band.

  18. Analysis of the impact of digital watermarking on computer-aided diagnosis in medical imaging.

    PubMed

    Garcia-Hernandez, Jose Juan; Gomez-Flores, Wilfrido; Rubio-Loyola, Javier

    2016-01-01

    Medical images (MI) are relevant sources of information for detecting and diagnosing a large number of illnesses and abnormalities. Due to their importance, this study is focused on breast ultrasound (BUS), which is the main adjunct for mammography to detect common breast lesions among women worldwide. On the other hand, aiming to enhance data security, image fidelity, authenticity, and content verification in e-health environments, MI watermarking has been widely used, whose main goal is to embed patient meta-data into MI so that the resulting image keeps its original quality. In this sense, this paper deals with the comparison of two watermarking approaches, namely spread spectrum based on the discrete cosine transform (SS-DCT) and the high-capacity data-hiding (HCDH) algorithm, so that the watermarked BUS images are guaranteed to be adequate for a computer-aided diagnosis (CADx) system, whose two principal outcomes are lesion segmentation and classification. Experimental results show that HCDH algorithm is highly recommended for watermarking medical images, maintaining the image quality and without introducing distortion into the output of CADx.

  19. Computer-aided diagnosis: detection and localization of prostate cancer within the peripheral zone.

    PubMed

    Rampun, Andrik; Chen, Zhili; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-05-01

    We propose a methodology for prostate cancer detection and localization within the peripheral zone based on combining multiple segmentation techniques. We extract four image features using Gaussian and median filters. Subsequently, we use each image feature separately to generate binary segmentations. Finally, we take the intersection of all four binary segmentations, incorporating a model of the peripheral zone, and perform erosion to remove small false-positive regions. The initial evaluation of this method is based on 275 MRI images from 37 patients, and 86% of the slices were classified correctly with 87% and 86% sensitivity and specificity achieved, respectively. This paper makes two contributions: firstly, a novel computer-aided diagnosis approach, which is based on combining multiple segmentation techniques using only a small number of simple image features, and secondly, the development of the proposed method and its application in prostate cancer detection and localization using a single MRI modality with the results comparable with the state-of-the-art multimodality and advanced computer vision methods in the literature. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Impact of lesion segmentation metrics on computer-aided diagnosis/detection in breast computed tomography

    PubMed Central

    Kuo, Hsien-Chi; Giger, Maryellen L.; Reiser, Ingrid; Drukker, Karen; Boone, John M.; Lindfors, Karen K.; Yang, Kai; Edwards, Alexandra

    2014-01-01

    Abstract. Evaluation of segmentation algorithms usually involves comparisons of segmentations to gold-standard delineations without regard to the ultimate medical decision-making task. We compare two segmentation evaluations methods—a Dice similarity coefficient (DSC) evaluation and a diagnostic classification task–based evaluation method using lesions from breast computed tomography. In our investigation, we use results from two previously developed lesion-segmentation algorithms [a global active contour model (GAC) and a global with local aspects active contour model]. Although similar DSC values were obtained (0.80 versus 0.77), we show that the global + local active contour (GLAC) model, as compared with the GAC model, is able to yield significantly improved classification performance in terms of area under the receivers operating characteristic (ROC) curve in the task of distinguishing malignant from benign lesions. [Area under the ROC curve (AUC)=0.78 compared to 0.63, p≪0.001]. This is mainly because the GLAC model yields better detailed information required in the calculation of morphological features. Based on our findings, we conclude that the DSC metric alone is not sufficient for evaluating segmentation lesions in computer-aided diagnosis tasks. PMID:26158052

  1. Computer-aided diagnosis of rheumatoid arthritis with optical tomography, Part 1: feature extraction

    PubMed Central

    Jia, Jingfei; Kim, Hyun K.; Netz, Uwe J.; Blaschke, Sabine; Müller, Gerhard A.

    2013-01-01

    Abstract. This is the first part of a two-part paper on the application of computer-aided diagnosis to diffuse optical tomography (DOT). An approach for extracting heuristic features from DOT images and a method for using these features to diagnose rheumatoid arthritis (RA) are presented. Feature extraction is the focus of Part 1, while the utility of five classification algorithms is evaluated in Part 2. The framework is validated on a set of 219 DOT images of proximal interphalangeal (PIP) joints. Overall, 594 features are extracted from the absorption and scattering images of each joint. Three major findings are deduced. First, DOT images of subjects with RA are statistically different (p<0.05) from images of subjects without RA for over 90% of the features investigated. Second, DOT images of subjects with RA that do not have detectable effusion, erosion, or synovitis (as determined by MRI and ultrasound) are statistically indistinguishable from DOT images of subjects with RA that do exhibit effusion, erosion, or synovitis. Thus, this subset of subjects may be diagnosed with RA from DOT images while they would go undetected by reviews of MRI or ultrasound images. Third, scattering coefficient images yield better one-dimensional classifiers. A total of three features yield a Youden index greater than 0.8. These findings suggest that DOT may be capable of distinguishing between PIP joints that are healthy and those affected by RA with or without effusion, erosion, or synovitis. PMID:23856915

  2. CAD/CAM/CNC.

    ERIC Educational Resources Information Center

    Domermuth, Dave; And Others

    1996-01-01

    Includes "Quick Start CNC (computer numerical control) with a Vacuum Filter and Laminated Plastic" (Domermuth); "School and Industry Cooperate for Mutual Benefit" (Buckler); and "CAD (computer-assisted drafting) Careers--What Professionals Have to Say" (Skinner). (JOW)

  3. Computer-aided design development transition for IPAD environment

    NASA Technical Reports Server (NTRS)

    Owens, H. G.; Mock, W. D.; Mitchell, J. C.

    1980-01-01

    The relationship of federally sponsored computer-aided design/computer-aided manufacturing (CAD/CAM) programs to the aircraft life cycle design process, an overview of NAAD'S CAD development program, an evaluation of the CAD design process, a discussion of the current computing environment within which NAAD is developing its CAD system, some of the advantages/disadvantages of the NAAD-IPAD approach, and CAD developments during transition into the IPAD system are discussed.

  4. Computerized nipple identification for multiple image analysis in computer-aided diagnosis

    SciTech Connect

    Zhou Chuan; Chan Heangping; Paramagul, Chintana; Roubidoux, Marilyn A.; Sahiner, Berkman; Hadjiiski, Labomir M.; Petrick, Nicholas

    2004-10-01

    Correlation of information from multiple-view mammograms (e.g., MLO and CC views, bilateral views, or current and prior mammograms) can improve the performance of breast cancer diagnosis by radiologists or by computer. The nipple is a reliable and stable landmark on mammograms for the registration of multiple mammograms. However, accurate identification of nipple location on mammograms is challenging because of the variations in image quality and in the nipple projections, resulting in some nipples being nearly invisible on the mammograms. In this study, we developed a computerized method to automatically identify the nipple location on digitized mammograms. First, the breast boundary was obtained using a gradient-based boundary tracking algorithm, and then the gray level profiles along the inside and outside of the boundary were identified. A geometric convergence analysis was used to limit the nipple search to a region of the breast boundary. A two-stage nipple detection method was developed to identify the nipple location using the gray level information around the nipple, the geometric characteristics of nipple shapes, and the texture features of glandular tissue or ducts which converge toward the nipple. At the first stage, a rule-based method was designed to identify the nipple location by detecting significant changes of intensity along the gray level profiles inside and outside the breast boundary and the changes in the boundary direction. At the second stage, a texture orientation-field analysis was developed to estimate the nipple location based on the convergence of the texture pattern of glandular tissue or ducts towards the nipple. The nipple location was finally determined from the detected nipple candidates by a rule-based confidence analysis. In this study, 377 and 367 randomly selected digitized mammograms were used for training and testing the nipple detection algorithm, respectively. Two experienced radiologists identified the nipple locations

  5. An image database management system for conducting CAD research

    NASA Astrophysics Data System (ADS)

    Gruszauskas, Nicholas; Drukker, Karen; Giger, Maryellen L.

    2007-03-01

    The development of image databases for CAD research is not a trivial task. The collection and management of images and their related metadata from multiple sources is a time-consuming but necessary process. By standardizing and centralizing the methods in which these data are maintained, one can generate subsets of a larger database that match the specific criteria needed for a particular research project in a quick and efficient manner. A research-oriented management system of this type is highly desirable in a multi-modality CAD research environment. An online, webbased database system for the storage and management of research-specific medical image metadata was designed for use with four modalities of breast imaging: screen-film mammography, full-field digital mammography, breast ultrasound and breast MRI. The system was designed to consolidate data from multiple clinical sources and provide the user with the ability to anonymize the data. Input concerning the type of data to be stored as well as desired searchable parameters was solicited from researchers in each modality. The backbone of the database was created using MySQL. A robust and easy-to-use interface for entering, removing, modifying and searching information in the database was created using HTML and PHP. This standardized system can be accessed using any modern web-browsing software and is fundamental for our various research projects on computer-aided detection, diagnosis, cancer risk assessment, multimodality lesion assessment, and prognosis. Our CAD database system stores large amounts of research-related metadata and successfully generates subsets of cases that match the user's desired search criteria.

  6. Computer-aided texture analysis combined with experts' knowledge: Improving endoscopic celiac disease diagnosis

    PubMed Central

    Gadermayr, Michael; Kogler, Hubert; Karla, Maximilian; Merhof, Dorit; Uhl, Andreas; Vécsei, Andreas

    2016-01-01

    AIM To further improve the endoscopic detection of intestinal mucosa alterations due to celiac disease (CD). METHODS We assessed a hybrid approach based on the integration of expert knowledge into the computer-based classification pipeline. A total of 2835 endoscopic images from the duodenum were recorded in 290 children using the modified immersion technique (MIT). These children underwent routine upper endoscopy for suspected CD or non-celiac upper abdominal symptoms between August 2008 and December 2014. Blinded to the clinical data and biopsy results, three medical experts visually classified each image as normal mucosa (Marsh-0) or villous atrophy (Marsh-3). The experts’ decisions were further integrated into state-of-the-art texture recognition systems. Using the biopsy results as the reference standard, the classification accuracies of this hybrid approach were compared to the experts’ diagnoses in 27 different settings. RESULTS Compared to the experts’ diagnoses, in 24 of 27 classification settings (consisting of three imaging modalities, three endoscopists and three classification approaches), the best overall classification accuracies were obtained with the new hybrid approach. In 17 of 24 classification settings, the improvements achieved with the hybrid approach were statistically significant (P < 0.05). Using the hybrid approach classification accuracies between 94% and 100% were obtained. Whereas the improvements are only moderate in the case of the most experienced expert, the results of the less experienced expert could be improved significantly in 17 out of 18 classification settings. Furthermore, the lowest classification accuracy, based on the combination of one database and one specific expert, could be improved from 80% to 95% (P < 0.001). CONCLUSION The overall classification performance of medical experts, especially less experienced experts, can be boosted significantly by integrating expert knowledge into computer-aided diagnosis

  7. [Esophageal pathology in patients with the AIDS virus. Etiology and diagnosis].

    PubMed

    Varsky, C G; Yahni, V D; Freire, M C; Patrizio, E; Balbo, V; Benetucci, J; Boffi, A; Mattoni, R A; Luis; Alicia, M

    1991-01-01

    From 180 patients infected with human immunodeficiency virus (HIV) and followed-up for one year, 17 cases (9.44%) were referred to detect oesophageal pathology. They were prospectively analyzed through fibroscopy, radiology, biopsies for histopathology, virology and mycology and brush cytology. Most frequent symptoms were dysphagia. Odynophagia and retrosternal pain, usually associated, and not providing an accurate diagnostic clue. The most common causes of symptoms were oesophageal candidiasis (47.70%), and herpetic ulcers (23.52%) caused by herpes simplex virus (HSV) type 2. Reflux pathology was also found (11.76%). Cytomegalovirus, other opportunistic infections and tumors were not detected. Seven (64%) of the eleven patients with oesophageal candidiasis also had oral involvement. Four (66%) of six oesophageal ulcers were herpetic; two of them (50%) showed oral ulcers too, and one (25%) had perioral herpetic blisters. Almost in every case endoscopic features allowed diagnosis. Endoscopy in candidiasis showed isolated or confluent white plaques of variable grade. Herpetic ulcers, alone or multiple, were deep with slightly elevated borders. Radiology yielded a poor diagnostic profit (50%), specially in case of multiple lesions. Cytology was highly specific and sensitive (both 90.9%) and suggested viral etiology in 100% of HSV patients. Histopathology was less sensitive than endoscopy and cytology (73% in candida and one HSV non-ulcer case). Both, cytology and histopathology showed koilocytosis in herpetic virus infected patients. The studies performed allowed to change the HIV disease stage in ten patients (62.5%) and to diagnose AIDS in seven (43.75%). In every case medical behavior was oriented or changed by these studies.

  8. Stepwise linear discriminant analysis in computer-aided diagnosis: the effect of finite sample size

    NASA Astrophysics Data System (ADS)

    Sahiner, Berkman; Chan, Heang-Ping; Petrick, Nicholas; Wagner, Robert F.; Hadjiiski, Lubomir M.

    1999-05-01

    In computer-aided diagnosis, a frequently-used approach is to first extract several potentially useful features from a data set. Effective features are then selected from this feature space, and a classifier is designed using the selected features. In this study, we investigated the effect of finite sample size on classifier accuracy when classifier design involves feature selection. The feature selection and classifier coefficient estimation stages of classifier design were implemented using stepwise feature selection and Fisher's linear discriminant analysis, respectively. The two classes used in our simulation study were assumed to have multidimensional Gaussian distributions, with a large number of features available for feature selection. We investigated the effect of different covariance matrices and means for the two classes on feature selection performance, and compared two strategies for sample space partitioning for classifier design and testing. Our results indicated that the resubstitution estimate was always optimistically biased, except in cases where too few features were selected by the stepwise procedure. When feature selection was performed using only the design samples, the hold-out estimate was always pessimistically biased. When feature selection was performed using the entire finite sample space, and the data was subsequently partitioned into design and test groups, the hold-out estimates could be pessimistically or optimistically biased, depending on the number of features available for selection, number of available samples, and their statistical distribution. All hold-out estimates exhibited a pessimistic bias when the parameters of the simulation were obtained from texture features extracted from mammograms in a previous study.

  9. Computer-aided texture analysis combined with experts' knowledge: Improving endoscopic celiac disease diagnosis

    PubMed Central

    Gadermayr, Michael; Kogler, Hubert; Karla, Maximilian; Merhof, Dorit; Uhl, Andreas; Vécsei, Andreas

    2016-01-01

    AIM To further improve the endoscopic detection of intestinal mucosa alterations due to celiac disease (CD). METHODS We assessed a hybrid approach based on the integration of expert knowledge into the computer-based classification pipeline. A total of 2835 endoscopic images from the duodenum were recorded in 290 children using the modified immersion technique (MIT). These children underwent routine upper endoscopy for suspected CD or non-celiac upper abdominal symptoms between August 2008 and December 2014. Blinded to the clinical data and biopsy results, three medical experts visually classified each image as normal mucosa (Marsh-0) or villous atrophy (Marsh-3). The experts’ decisions were further integrated into state-of-the-art texture recognition systems. Using the biopsy results as the reference standard, the classification accuracies of this hybrid approach were compared to the experts’ diagnoses in 27 different settings. RESULTS Compared to the experts’ diagnoses, in 24 of 27 classification settings (consisting of three imaging modalities, three endoscopists and three classification approaches), the best overall classification accuracies were obtained with the new hybrid approach. In 17 of 24 classification settings, the improvements achieved with the hybrid approach were statistically significant (P < 0.05). Using the hybrid approach classification accuracies between 94% and 100% were obtained. Whereas the improvements are only moderate in the case of the most experienced expert, the results of the less experienced expert could be improved significantly in 17 out of 18 classification settings. Furthermore, the lowest classification accuracy, based on the combination of one database and one specific expert, could be improved from 80% to 95% (P < 0.001). CONCLUSION The overall classification performance of medical experts, especially less experienced experts, can be boosted significantly by integrating expert knowledge into computer-aided diagnosis

  10. Distance weighted 'inside disc' classifier for computer-aided diagnosis of colonic polyps

    NASA Astrophysics Data System (ADS)

    Hu, Yifan; Song, Bowen; Pickhardt, Perry J.; Liang, Zhengrong

    2015-03-01

    Feature classification plays an important role in computer-aided diagnosis (CADx) of suspicious lesions or polyps in this concerned study. As one of the simplest machine learning algorithms, the k-nearest neighbor (k-NN) classifier has been widely used in many classification problems. However, the k-NN classifier has a drawback that the majority classes will dominate the prediction of a new sample. To mitigate this drawback, efforts have been devoted to set weight on each neighbor to avoid the influence of the "majority" classes. As a result, various weighted or wk-NN strategies have been explored. In this paper, we explored an alternative strategy, called "distance weighted inside disc" (DWID) classifier, which is different from the k-NN and wk-NN by such a way that it classifies the test point by assigning a corresponding label (instead a weight) with consideration of only those points inside the disc whose center is the test point instead of the k-nearest points. We evaluated this new DWID classifier with comparison to the k-NN, wk-NN, support vector machine (SVM) and random forest (RF) classifiers by experiments on a database of 153 polyps, including 116 neoplastic (malignance) polyps and 37 hyperplastic (benign) polyps, in terms of CADx or differentiation of benign from malignancy. The evaluation outcomes were documented quantitatively by the Receiver Operating Characteristics (ROC) analysis and the merit of area under the ROC curve (AUC), which is a well-established evaluation criterion to various classifiers. The results showed noticeable gain on the polyp differentiation by this new classifier according to the AUC values, as compared to the k-NN and wk-NN, as well as the SVM and RF. In the meantime, this new classifier also showed a noticeable reduction of computing time.

  11. Schools (Students) Exchanging CAD/CAM Files over the Internet.

    ERIC Educational Resources Information Center

    Mahoney, Gary S.; Smallwood, James E.

    This document discusses how students and schools can benefit from exchanging computer-aided design/computer-aided manufacturing (CAD/CAM) files over the Internet, explains how files are exchanged, and examines the problem of selected hardware/software incompatibility. Key terms associated with information search services are defined, and several…

  12. Resin-composite Blocks for Dental CAD/CAM Applications

    PubMed Central

    Ruse, N.D.; Sadoun, M.J.

    2014-01-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. PMID:25344335

  13. Resin-composite blocks for dental CAD/CAM applications.

    PubMed

    Ruse, N D; Sadoun, M J

    2014-12-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.

  14. Extenuating Circumstances in Perceptions of Suicide: Disease Diagnosis (AIDS, Cancer), Pain Level, and Life Expectancy.

    ERIC Educational Resources Information Center

    Martin, Stephen K.; Range, Lillian M.

    1991-01-01

    Examined whether illness type, pain level, and life expectancy affected reactions of undergraduates (n=160) toward a terminal illness suicide with Acquired Immune Deficiency Syndrome (AIDS) or cancer. AIDS patients were more stigmatized than cancer patients; suicide was more tolerated if victim was suffering greater pain. (Author/ABL)

  15. Adaptive thresholding of chest temporal subtraction images in computer-aided diagnosis of pathologic change

    NASA Astrophysics Data System (ADS)

    Harrison, Melanie; Looper, Jared; Armato, Samuel G.

    2016-03-01

    Radiologists frequently use chest radiographs acquired at different times to diagnose a patient by identifying regions of change. Temporal subtraction (TS) images are formed when a computer warps a radiographic image to register and then subtract one image from the other, accentuating regions of change. The purpose of this study was to create a computeraided diagnostic (CAD) system to threshold chest TS images and identify candidate regions of pathologic change. Each thresholding technique created two different candidate regions: light and dark. Light regions have a high gray-level mean, while dark regions have a low gray-level mean; areas with no change appear as medium-gray pixels. Ten different thresholding techniques were examined and compared. By thresholding light and dark candidate regions separately, the number of properly thresholded regions improved. The thresholding of light and dark regions separately produced fewer overall candidate regions that included more regions of actual pathologic change than global thresholding of the image. Overall, the moment-preserving method produced the best results for light regions, while the normal distribution method produced the best results for dark regions. Separation of light and dark candidate regions by thresholding shows potential as the first step in creating a CAD system to detect pathologic change in chest TS images.

  16. Retrieval boosted computer-aided diagnosis of clustered microcalcifications for breast cancer

    PubMed Central

    Jing, Hao; Yang, Yongyi; Nishikawa, Robert M.

    2012-01-01

    Purpose: The authors propose an image-retrieval based approach for case-adaptive classifier design in computer-aided diagnosis (CADx). The conventional approach in CADx is to first train a pattern-classifier based on a set of existing training samples and then apply this classifier to subsequent new cases. The purpose of this work is to improve the classification accuracy of a CADx classifier by making use of a set of known cases retrieved from a reference library that are similar to the case under consideration. Methods: In the proposed approach, the authors will first apply image-retrieval to obtain a set of lesion images from a library of known cases that have similar image features to a case being diagnosed (i.e., query). These retrieved cases are then used to optimize a pattern-classifier toward boosting its classification accuracy on the query case. The basic idea is to put more emphasis on those cases that are similar to the query. The proposed approach is demonstrated first using a linear classifier and then extended to a nonlinear classifier induced by kernel principal component analysis. Results: The proposed retrieval-driven approach was tested on a library of mammogram images from 1006 cases (646 benign and 360 malignant) obtained from multiple institutions and was demonstrated to yield significant improvement in classification performance. Measured by the area under the receiver operating characteristic curve (AUC), the case-adaptive approach could boost the classification performance of a linear classifier from AUC = 0.7415 to AUC = 0.7807; similar improvement was also obtained for a nonlinear classifier, with AUC boosted from 0.7527 to 0.7838. Conclusions: Use of additional cases from a reference library that have similar image features can improve the classification accuracy of a CADx classifier on a query case. It can even outperform retraining the classifier with all the cases from the entire reference library. This implies that cases with

  17. Integrated Computer-Aided Drafting Instruction (ICADI).

    ERIC Educational Resources Information Center

    Chen, C. Y.; McCampbell, David H.

    Until recently, computer-aided drafting and design (CAD) systems were almost exclusively operated on mainframes or minicomputers and their cost prohibited many schools from offering CAD instruction. Today, many powerful personal computers are capable of performing the high-speed calculation and analysis required by the CAD application; however,…

  18. Computer-Aided Design in Further Education.

    ERIC Educational Resources Information Center

    Ingham, Peter, Ed.

    This publication updates the 1982 occasional paper that was intended to foster staff awareness and assist colleges in Great Britain considering the use of computer-aided design (CAD) material in engineering courses. The paper begins by defining CAD and its place in the Integrated Business System with a brief discussion of the effect of CAD on the…

  19. Improving the Accuracy of CT Colonography Interpretation: Computer-Aided Diagnosis

    PubMed Central

    Summers, Ronald M.

    2010-01-01

    Synopsis Computer-aided polyp detection aims to improve the accuracy of the colonography interpretation. The computer searches the colonic wall to look for polyp-like protrusions and presents a list of suspicious areas to a physician for further analysis. Computer-aided polyp detection has developed rapidly over the past decade and in the laboratory setting and has sensitivities comparable to those of experts. Computer-aided polyp detection tends to help inexperienced readers more than experienced ones and may also lead to small reductions in specificity. In its currently proposed use as an adjunct to standard image interpretation, computer-aided polyp detection serves as a spellchecker rather than an efficiency enhancer. PMID:20451814

  20. Effect of CAD on radiologists' detection of lung nodules on thoracic CT scans: observer performance study

    NASA Astrophysics Data System (ADS)

    Sahiner, Berkman; Hadjiiski, Lubomir M.; Chan, Heang-Ping; Shi, Jiazheng; Cascade, Philip N.; Kazerooni, Ella A.; Zhou, Chuan; Wei, Jun; Chughtai, Aamer R.; Poopat, Chad; Song, Thomas; Nojkova, Jadranka S.; Frank, Luba; Attili, Anil

    2007-03-01

    The purpose of this study was to evaluate the effect of computer-aided diagnosis (CAD) on radiologists' performance for the detection of lung nodules on thoracic CT scans. Our computer system was designed using an independent training set of 94 CT scans in our laboratory. The data set for the observer performance study consisted of 48 CT scans. Twenty scans were collected from patient files at the University of Michigan, and 28 scans by the Lung Imaging Database Consortium (LIDC). All scans were read by multiple experienced thoracic radiologists to determine the true nodule locations, defined as any region identified by one or more expert radiologists as containing a nodule larger than 3 mm in diameter. Eighteen CT examinations were nodule-free, while the remaining 30 CT examinations contained a total of 73 nodules having a median size of 5.5 mm (range 3.0-36.4 mm). Four other study radiologists read the CT scans first without and then with CAD, and provided likelihood of nodule ratings for suspicious regions. Two of the study radiologists were fellowship trained in cardiothoracic radiology, and two were cardiothoracic radiology fellows. Freeresponse receiver-operating characteristic (FROC) curves were used to compare the two reading conditions. The computer system had a sensitivity of 79% (58/73) with an average of 4.9 marks per normal scan (88/18). Jackknife alternative FROC (JAFROC) analysis indicated that the improvement with CAD was statistically significant (p=0.03).

  1. Diagnosis and screening of coronary artery disease.

    PubMed

    Anthony, David

    2005-12-01

    Diagnostic testing for CAD is aided by the calculation of the pretest probability using either the Diamond-Forrester score or the Morise score. Patients who have a low risk of CAD should not undergo testing. Exercise ECG testing should be reserved for patients who have pretest probabilities lower than 20%, because a negative test does not adequately reduce the posttest probability of significant CAD. For patients who are at intermediate risk, either nuclear perfusion imaging or stress echocardiography is an acceptable choice depending on local availability and practice. Due to its low specificity, CAC scoring is currently limited in its usefulness for the diagnosis of CAD in symptomatic patients. Currently, screening for CAD among patients at low risk should not extend beyond screening for traditional risk factors. Physicians should use the Framingham Risk Score to stratify patients into levels of 10-year risk for cardiac events. Due to its high rate of false positive tests and low sensitivity, exercise ECG is of limited value in screening. Among patients with higher levels of risk, in whom further risk stratification would be of use in making decisions about risk factor management, measurement of CAC either with EBCT or multidetector row CT scanning is a promising option, but more research is required before its use should become widespread. Measures of endothelial function are in development but lack data to support their widespread use currently. PMID:16326220

  2. Generating Composite Overlapping Grids on CAD Geometries

    SciTech Connect

    Henshaw, W.D.

    2002-02-07

    We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids using hyperbolic grid generation, and (5) generate the overlapping grid by determining the holes and the interpolation points. The overlapping grid generator which is used for the final step also supports the rapid generation of grids for block-structured adaptive mesh refinement and for moving grids. These algorithms have been implemented as part of the Overture object-oriented framework.

  3. CAD/CAM systems, materials, and clinical guidelines for all-ceramic crowns and fixed partial dentures.

    PubMed

    McLaren, Edward A; Terry, Douglas A

    2002-07-01

    Advances in dental ceramic materials and the development of computer-aided design/computer-aided manufacturing (CAD/CAM) and milling technology have facilitated the development and application of superior dental ceramics. CAD/CAM allows the use of materials that cannot be used with conventional dental processing techniques. This article reviews the main techniques and new materials used in dentistry for CAD/CAM-generated crowns and fixed partial dentures. Also covered are the clinical guidelines for using these systems.

  4. A hybrid fuzzy-neural system for computer-aided diagnosis of ultrasound kidney images using prominent features.

    PubMed

    Bommanna Raja, K; Madheswaran, M; Thyagarajah, K

    2008-02-01

    The objective of this work is to develop and implement a computer-aided decision support system for an automated diagnosis and classification of ultrasound kidney images. The proposed method distinguishes three kidney categories namely normal, medical renal diseases and cortical cyst. For the each pre-processed ultrasound kidney image, 36 features are extracted. Two types of decision support systems, optimized multi-layer back propagation network and hybrid fuzzy-neural system have been developed with these features for classifying the kidney categories. The performance of the hybrid fuzzy-neural system is compared with the optimized multi-layer back propagation network in terms of classification efficiency, training and testing time. The results obtained show that fuzzy-neural system provides higher classification efficiency with minimum training and testing time. It has also been found that instead of using all 36 features, ranking the features enhance classification efficiency. The outputs of the decision support systems are validated with medical expert to measure the actual efficiency. The overall discriminating capability of the systems is accessed with performance evaluation measure, f-score. It has been observed that the performance of fuzzy-neural system is superior compared to optimized multi-layer back propagation network. Such hybrid fuzzy-neural system with feature extraction algorithms and pre-processing scheme helps in developing computer-aided diagnosis system for ultrasound kidney images and can be used as a secondary observer in clinical decision making.

  5. Correlative morphologic and functional imaging for diagnosis, staging and follow up in AIDS: an overview.

    PubMed

    Brunetti, A; Soricelli, A; Rotondo, A; Alfano, B; Raman, R; Celentano, L; Di Chiro, G; Salvatore, M

    1995-09-01

    The immunocompromised patient can be affected by different opportunistic infections and tumors, that can involve all organ systems, and particularly, the central nervous system, the respiratory system, the gastrointestinal tract. The extreme variability of AIDS presentations requires a specific preparation and cooperation between the different diagnostic imaging specialists and a close collaboration with the clinicians. With AIDS, different morphologic and functional imaging techniques can be used for detection of disease sites, assessment of the extent of the disease and monitoring of disease changes over time and response to treatment. The complexity of AIDS presentations is such that full integration of the complementary information obtained with different techniques could be most useful. Image registration (coregistration, fusion) indicates approaches where precise spatial cross-references are obtained, in order to combine the information acquired with different imaging modalities, in particular by blending morphologic CT/MRI data with functional SPET/PET data. In this paper, an overview of the developments in the field of "image fusion" follows some comments on the results of morphologic and functional assessment of brain, chest and abdominal diseases in the course of AIDS, as illustrative examples of the potential benefits of multimodality image correlation.

  6. An information theoretic view of the scheduling problem in whole-body CAD

    NASA Astrophysics Data System (ADS)

    Zhan, Yiqiang; Zhou, Xiang Sean; Krishnan, Arun

    2008-03-01

    Emerging whole-body imaging technologies push computer aided detection/diagnosis (CAD) to scale up to a whole-body level, which involves multiple organs or anatomical structure. To be exploited in this paper is the fact that the various tasks in whole-body CAD are often highly dependent (e.g., the localization of the femur heads strongly predicts the position of the iliac bifurcation of the aorta). One way to effectively employ task dependency is to schedule the tasks such that outputs of some tasks are used to guide the others. In this sense, optimal task scheduling is key to improve overall performance of a whole-body CAD system. In this paper, we propose a method for task scheduling that is optimal in an information-theoretic sense. The central idea is to schedule tasks in such an order that each operation achieves maximum expected information gain over all the tasks. The formulation embeds two intuitive principles: (1) a task with higher confidence tends to be scheduled earlier; (2) a task with higher predictive power for other tasks tends to be scheduled earlier. More specifically, task dependency is modeled by conditional probability; the outcome of each task is assumed to be probabilistic as well; and the objective function is based on the reduction of the summed conditional entropy over all tasks. The validation is carried out on a challenging CAD problem, multi-organ localization in whole-body CT. Compared to unscheduled and ad hoc scheduled organ detection/localization, our scheduled execution achieves higher accuracy with much less computation time.

  7. Computer Use and CAD in Assisting Schools in the Creation of Facilities.

    ERIC Educational Resources Information Center

    Beach, Robert H.; Essex, Nathan

    1987-01-01

    Computer-aided design (CAD) programs are powerful drafting tools, but are also able to assist with many other facility planning functions. Describes the hardware, software, and the learning process that led to understanding the CAD software at the University of Alabama. (MLF)

  8. The Use of a Parametric Feature Based CAD System to Teach Introductory Engineering Graphics.

    ERIC Educational Resources Information Center

    Howell, Steven K.

    1995-01-01

    Describes the use of a parametric-feature-based computer-aided design (CAD) System, AutoCAD Designer, in teaching concepts of three dimensional geometrical modeling and design. Allows engineering graphics to go beyond the role of documentation and communication and allows an engineer to actually build a virtual prototype of a design idea and…

  9. Teaching an Introductory CAD Course with the System-Engineering Approach.

    ERIC Educational Resources Information Center

    Pao, Y. C.

    1985-01-01

    Advocates that introductory computer aided design (CAD) courses be incorporated into engineering curricula in close conjunction with the system dynamics course. Block diagram manipulation/Bode analysis and finite elementary analysis are used as examples to illustrate the interdisciplinary nature of CAD teaching. (JN)

  10. Computer aided diagnosis for osteoporosis based on vertebral column structure analysis

    NASA Astrophysics Data System (ADS)

    Takahashi, Eiji; Kawata, Yoshiki; Niki, Noboru; Nakano, Yasutaka; Harada, Masafumi; Moriyama, Noriyuki

    2012-03-01

    Patients of osteoporosis are comprised of about 11 million people in Japan and it is one of the problems that have gained society. For preventing the osteoporosis, obtaining early detection and treatment are necessary. Multi-slice CT technology has been improving for three dimensional (3D) image analysis, higher body axis resolution and shorter scan time. 3D image analysis using multi-slice CT images of thoracic vertebra can be used for supporting diagnosis of osteoporosis. Simultaneously, this analysis can be used for lung cancer diagnosis which may lead to early detection. We develop automatic extraction and partitioning algorithm for spinal column by analyzing vertebral body structure, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the diagnosis of osteoporosis. An effective result was provided for the case including an insufficient complicated vertebral body bone fracture by the conventional method.

  11. Computer-aided diagnosis for osteoporosis using chest 3D CT images

    NASA Astrophysics Data System (ADS)

    Yoneda, K.; Matsuhiro, M.; Suzuki, H.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.

    2016-03-01

    The patients of osteoporosis comprised of about 13 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. Multi-slice CT technology has been improving the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer diagnosis which may lead to early detection. We develop automatic extraction and partitioning algorithm for spinal column by analyzing vertebral body structure, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the diagnosis of osteoporosis. Osteoporosis diagnosis support system obtained high extraction rate of the thoracic vertebral in both normal and low doses.

  12. A new CAD approach for improving efficacy of cancer screening

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Qian, Wei; Li, Lihua; Pu, Jiantao; Kang, Yan; Lure, Fleming; Tan, Maxine; Qiu, Yuchen

    2015-03-01

    Since performance and clinical utility of current computer-aided detection (CAD) schemes of detecting and classifying soft tissue lesions (e.g., breast masses and lung nodules) is not satisfactory, many researchers in CAD field call for new CAD research ideas and approaches. The purpose of presenting this opinion paper is to share our vision and stimulate more discussions of how to overcome or compensate the limitation of current lesion-detection based CAD schemes in the CAD research community. Since based on our observation that analyzing global image information plays an important role in radiologists' decision making, we hypothesized that using the targeted quantitative image features computed from global images could also provide highly discriminatory power, which are supplementary to the lesion-based information. To test our hypothesis, we recently performed a number of independent studies. Based on our published preliminary study results, we demonstrated that global mammographic image features and background parenchymal enhancement of breast MR images carried useful information to (1) predict near-term breast cancer risk based on negative screening mammograms, (2) distinguish between true- and false-positive recalls in mammography screening examinations, and (3) classify between malignant and benign breast MR examinations. The global case-based CAD scheme only warns a risk level of the cases without cueing a large number of false-positive lesions. It can also be applied to guide lesion-based CAD cueing to reduce false-positives but enhance clinically relevant true-positive cueing. However, before such a new CAD approach is clinically acceptable, more work is needed to optimize not only the scheme performance but also how to integrate with lesion-based CAD schemes in the clinical practice.

  13. Automated detection of clustered microcalcifications on mammograms: CAD system application to MIAS database

    NASA Astrophysics Data System (ADS)

    Ibrahim, Norhayati; Fujita, Hiroshi; Hara, Takeshi; Endo, Tokiko

    1997-12-01

    To investigate the detection performance of our automated detection scheme for clustered microcalcifications on mammograms, we applied our computer-aided diagnosis (CAD) system to the database of the Mammographic Image Analysis Society (MIAS) in the UK. Forty-three mammograms from this database were used in this study. In our scheme, the breast regions were firstly extracted by determining the skinline. Histograms of the original images were used to extract the high-density area within the breast region as the segmentation from the fatty area around the skinline. Then the contrast correction technique was employed. Gradient vectors of the image density were calculated on the contrast corrected images. To extract the specific features of the pattern of the microcalcifications, triple-ring filter analysis was employed. A variable-ring filter was used for more accurate detection after the triple-ring filter. The features of the detected candidate areas were then characterized by feature analysis. The areas which satisfied the characteristics and specific terms were classified and displayed as clusters. As a result, the sensitivity was 95.8% with the false-positive rate at 1.8 clusters per image. This demonstrates that the automated detection of clustered microcalcifications in our CAD system is reliable as an aid to radiologists.

  14. Fungal Malignant Otitis Externa with Facial Nerve Palsy: Tissue Biopsy Aids Diagnosis

    PubMed Central

    Walton, Jenny

    2014-01-01

    Fungal malignant otitis externa (FMOE) is a serious and potentially life-threatening condition that is challenging to manage. Diagnosis is often delayed due to the low sensitivity of aural swabs and many antifungal drugs have significant side effects. We present a case of FMOE, where formal tissue sampling revealed the diagnosis and the patient was successfully treated with voriconazole, in addition to an up to date review of the current literature. We would recommend tissue biopsy of the external auditory canal in all patients with suspected FMOE in addition to routine microbiology swabs. PMID:24649388

  15. SVM-based CAD system for early detection of the Alzheimer's disease using kernel PCA and LDA.

    PubMed

    López, M M; Ramírez, J; Górriz, J M; Alvarez, I; Salas-Gonzalez, D; Segovia, F; Chaves, R

    2009-10-30

    Single-photon emission tomography (SPECT) imaging has been widely used to guide clinicians in the early Alzheimer's disease (AD) diagnosis challenge. However, AD detection still relies on subjective steps carried out by clinicians, which entail in some way subjectivity to the final diagnosis. In this work, kernel principal component analysis (PCA) and linear discriminant analysis (LDA) are applied on functional images as dimension reduction and feature extraction techniques, which are subsequently used to train a supervised support vector machine (SVM) classifier. The complete methodology provides a kernel-based computer-aided diagnosis (CAD) system capable to distinguish AD from normal subjects with 92.31% accuracy rate for a SPECT database consisting of 91 patients. The proposed methodology outperforms voxels-as-features (VAF) that was considered as baseline approach, which yields 80.22% for the same SPECT database.

  16. CAD/CAM for optomechatronics

    NASA Astrophysics Data System (ADS)

    Zhou, Haiguang; Han, Min

    2003-10-01

    We focus at CAD/CAM for optomechatronics. We have developed a kind of CAD/CAM, which is not only for mechanics but also for optics and electronic. The software can be used for training and education. We introduce mechanical CAD, optical CAD and electrical CAD, we show how to draw a circuit diagram, mechanical diagram and luminous transmission diagram, from 2D drawing to 3D drawing. We introduce how to create 2D and 3D parts for optomechatronics, how to edit tool paths, how to select parameters for process, how to run the post processor, dynamic show the tool path and generate the CNC programming. We introduce the joint application of CAD&CAM. We aim at how to match the requirement of optical, mechanical and electronics.

  17. Computer Aided Drafting Workshop. Workshop Booklet.

    ERIC Educational Resources Information Center

    Goetsch, David L.

    This mini-course and article are presentations from a workshop on computer-aided drafting. The purpose of the mini-course is to assist drafting instructors in updating their occupational knowledge to include computer-aided drafting (CAD). Topics covered in the course include general computer information, the computer in drafting, CAD terminology,…

  18. Computer Aided Design in Engineering Education.

    ERIC Educational Resources Information Center

    Gobin, R.

    1986-01-01

    Discusses the use of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) systems in an undergraduate engineering education program. Provides a rationale for CAD/CAM use in the already existing engineering program. Describes the methods used in choosing the systems, some initial results, and warnings for first-time users. (TW)

  19. Computerized design of CAD

    NASA Astrophysics Data System (ADS)

    Paul, B. E.; Pham, T. A.

    1982-11-01

    A computerized ballistic design technique for CAD/PAD is described by which a set of ballistic design parameters are determined, all of which satisfy a particular performance requirement. In addition, the program yields the remaining performance predictions, so that only a very few computer runs of the design program can quickly bring the ballistic design within the specification limits prescribed. An example is presented for a small propulsion device, such as a remover or actuator, for which the input specifications define a maximum allowable thrust and minimum end-of-stroke velocity. The resulting output automatically satisfies the input requirements, and will always yield an acceptable ballistic design.

  20. CAD programs: a tool for crime scene processing and reconstruction

    NASA Astrophysics Data System (ADS)

    Boggiano, Daniel; De Forest, Peter R.; Sheehan, Francis X.

    1997-02-01

    Computer aided drafting (CAD) programs have great potential for helping the forensic scientist. One of their most direct and useful applications is crime scene documentation, as an aid in rendering neat, unambiguous line drawings of crime scenes. Once the data has been entered, it can easily be displayed, printed, or plotted in a variety of formats. Final renditions from this initial data entry can take multiple forms and can have multiple uses. As a demonstrative aid, a CAD program can produce two dimensional (2-D) drawings of the scene from one's notes to scale. These 2-D renditions are court display quality and help to make the forensic scientists's testimony easily understood. Another use for CAD is as an analytical tool for scene reconstruction. More than just a drawing aid, CAD can generate useful information from the data input. It can help reconstruct bullet paths or locations of furniture in a room when it is critical to the reconstruction. Data entry at the scene, on a notebook computer, can assist in framing and answering questions so that the forensic scientist can test hypotheses while actively documenting the scene. Further, three dimensional (3-D) renditions of items can be viewed from many 'locations' by using the program to rotate the object and the observers' viewpoint.

  1. Correlating Trainee Attributes to Performance in 3D CAD Training

    ERIC Educational Resources Information Center

    Hamade, Ramsey F.; Artail, Hassan A.; Sikstrom, Sverker

    2007-01-01

    Purpose: The purpose of this exploratory study is to identify trainee attributes relevant for development of skills in 3D computer-aided design (CAD). Design/methodology/approach: Participants were trained to perform cognitive tasks of comparable complexity over time. Performance data were collected on the time needed to construct test models, and…

  2. Program Evolves from Basic CAD to Total Manufacturing Experience

    ERIC Educational Resources Information Center

    Cassola, Joel

    2011-01-01

    Close to a decade ago, John Hersey High School (JHHS) in Arlington Heights, Illinois, made a transition from a traditional classroom-based pre-engineering program. The new program is geared towards helping students understand the entire manufacturing process. Previously, a JHHS student would design a project in computer-aided design (CAD) software…

  3. Utility of Functional Hemodynamics and Echocardiography to Aid Diagnosis and Management of Shock.

    PubMed

    McGee, William T; Raghunathan, Karthik; Adler, Adam C

    2015-12-01

    The utility of functional hemodynamics and bedside ultrasonography is increasingly recognized as advantageous for both improved diagnosis and management of shock states. In contrast to conventional "static" measures, "dynamic" hemodynamic measures and bedside imaging modalities enhance pathophysiology-based comprehensive understanding of shock states and the response to therapy. The current editions of major textbooks in the primary specialties--in which clinicians routinely encounter patients in shock--including surgery, anesthesia, emergency medicine, and internal medicine continue to incorporate traditional (conventional) descriptions of shock that use well-described (but potentially misleading) intravascular pressures to classify shock states. Reliance on such intravascular pressure measurements is not as helpful as newer "dynamic" functional measures including ultrasonography to both better assess volume responsiveness and biventricular cardiac function. This review thus emphasizes the application of current functional hemodynamics and ultrasonography to the diagnosis and management of shock as a contrast to conventional "static" pressure-based measures.

  4. SeDeLo: using semantics and description logics to support aided clinical diagnosis.

    PubMed

    Rodríguez-González, Alejandro; Labra-Gayo, Jose Emilio; Colomo-Palacios, Ricardo; Mayer, Miguel A; Gómez-Berbís, Juan Miguel; García-Crespo, Angel

    2012-08-01

    Automated medical diagnosis systems based on knowledge-oriented descriptions have gained momentum with the emergence of semantic descriptions. The objective of this paper is to propose a normalized design that solves some of the problems which have been detected by authors in previous tools. The authors bring together two different technologies to develop a new clinical decision support system: description logics aimed at developing inference systems to improve decision support for the prevention, treatment and management of illness and semantic technologies. Because of its new design, the system is capable of obtaining improved diagnostics compared with previous efforts. However, this evaluation is more focused in the computational performance, giving as result that description logics is a good solution with small data sets. In this paper, we provide a well-structured ontology for automated diagnosis in the medical field and a three-fold formalization based on Description Logics with the use of Semantic Web technologies.

  5. Laser Doppler flowmetry: an aid in differential diagnosis of apical radiolucencies.

    PubMed

    Chandler, N P; Love, R M; Sundqvist, G

    1999-05-01

    The case of a patient having 2 teeth with associated apical radiolucencies that responded to conventional pulp tests is presented. A decision was made to reexamine the patient at intervals rather than perform root canal treatment. During a recall visit, use of an available laser Doppler flowmeter allowed detection of blood flow within the affected teeth. A diagnosis of periapical cemental dysplasia (cementoma) was made. PMID:10348523

  6. Infantile granular parakeratosis: cytologic examination of superficial scrapings as an aid to diagnosis.

    PubMed

    Akkaya, A Deniz; Oram, Yasemin; Aydın, Özlem

    2015-01-01

    Granular parakeratosis (GP) is a benign disorder of keratinization presenting with unilateral or bilateral red to brown hyperkeratotic plaques and papules at the intertriginous areas. The first pediatric case of GP was reported in 2002, and only a few cases have been reported since. Although the exact etiology of GP is unknown, it is thought that certain environmental factors compromise the epidermal barrier and lead to proliferation and altered maturation of the epidermis in predisposed individuals. The histopathology is diagnostic and reveals parakeratosis together with retention of keratohyalin granules within a disproportionately thickened stratum corneum and usually the preservation of stratum granulosum. Herein we report seven cases of infantile GP, six of which also had atopic dermatitis. Cytologic examination confirmed our clinical diagnosis by demonstrating the retention of keratohyalin granules and preservation of the nuclei from the superficial scrapings of the lesions, which we propose as a novel diagnostic technique. In all seven cases the lesions developed after the overuse of topical products and resolved with avoidance of their excessive use. We propose that atopic skin may be more prone to develop GP because the epidermal barrier is disrupted, resulting in the enhanced transepidermal penetration of topical products. In conclusion, GP should be included in the differential diagnosis of diaper area eruptions, especially in atopic children. Cytologic examination of superficial scrapings of the lesions can easily confirm the diagnosis of GP. PMID:25660113

  7. Computer-aided differential diagnosis in movement disorders using MRI morphometry

    NASA Astrophysics Data System (ADS)

    Duchesne, S.; Roland, Y.; Verin, M.; Barillot, C.

    2007-03-01

    Background: Reported error rates for initial clinical diagnosis in parkinsonian disorders can reach up to 35%. Reducing this initial error rate is an important research goal. The objective of this work is to evaluate the ability of an automated MR-based classification technique in the differential diagnosis of Parkinson's disease (PD), multiple systems atrophy (MSA) and progressive supranuclear palsy (PSP). Methods: A total of 172 subjects were included in this study: 152 healthy subjects, 10 probable PD patients and 10 age-matched patients with diagnostic of either probable MSA or PSP. T1-weighted (T1w) MR images were acquired and subsequently corrected, scaled, resampled and aligned within a common referential space. Tissue transformation and deformation features were then automatically extracted. Classification of patients was performed using forward, stepwise linear discriminant analysis within a multidimensional transformation/deformation feature space built from healthy subjects data. Leave-one-out classification was used to avoid over-determination. Findings: There were no age difference between groups. Highest accuracy (agreement with long-term clinical follow-up) of 85% was achieved using a single MR-based deformation feature. Interpretation: These preliminary results demonstrate that a classification approach based on quantitative parameters of 3D brainstem morphology extracted automatically from T1w MRI has the potential to perform differential diagnosis of PD versus MSA/PSP with high accuracy.

  8. Study of Aided Diagnosis of Hepatic Carcinoma Based on Artificial Neural Network Combined with Tumor Marker Group

    NASA Astrophysics Data System (ADS)

    Tan, Shanjuan; Feng, Feifei; Wu, Yongjun; Wu, Yiming

    To develop a computer-aided diagnostic scheme by using an artificial neural network (ANN) combined with tumor markers for diagnosis of hepatic carcinoma (HCC) as a clinical assistant method. 140 serum samples (50 malignant, 40 benign and 50 normal) were analyzed for α-fetoprotein (AFP), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), sialic acid (SA) and calcium (Ca). The five tumor marker values were then used as ANN inputs data. The result of ANN was compared with that of discriminant analysis by receiver operating characteristic (ROC) curve (AUC) analysis. The diagnostic accuracy of ANN and discriminant analysis among all samples of the test group was 95.5% and 79.3%, respectively. Analysis of multiple tumor markers based on ANN may be a better choice than the traditional statistical methods for differentiating HCC from benign or normal.

  9. Fourier-based shape feature extraction technique for computer-aided B-Mode ultrasound diagnosis of breast tumor.

    PubMed

    Lee, Jong-Ha; Seong, Yeong Kyeong; Chang, Chu-Ho; Park, Jinman; Park, Moonho; Woo, Kyoung-Gu; Ko, Eun Young

    2012-01-01

    Early detection of breast tumor is critical in determining the best possible treatment approach. Due to its superiority compared with mammography in its possibility to detect lesions in dense breast tissue, ultrasound imaging has become an important modality in breast tumor detection and classification. This paper discusses the novel Fourier-based shape feature extraction techniques that provide enhanced classification accuracy for breast tumor in the computer-aided B-mode ultrasound diagnosis system. To demonstrate the effectiveness of the proposed method, experiments were performed using 4,107 ultrasound images with 2,508 malignancy cases. Experimental results show that the breast tumor classification accuracy of the proposed technique was 15.8%, 5.43%, 17.32%, and 13.86% higher than the previous shape features such as number of protuberances, number of depressions, lobulation index, and dissimilarity, respectively. PMID:23367430

  10. Fourier-based shape feature extraction technique for computer-aided B-Mode ultrasound diagnosis of breast tumor.

    PubMed

    Lee, Jong-Ha; Seong, Yeong Kyeong; Chang, Chu-Ho; Park, Jinman; Park, Moonho; Woo, Kyoung-Gu; Ko, Eun Young

    2012-01-01

    Early detection of breast tumor is critical in determining the best possible treatment approach. Due to its superiority compared with mammography in its possibility to detect lesions in dense breast tissue, ultrasound imaging has become an important modality in breast tumor detection and classification. This paper discusses the novel Fourier-based shape feature extraction techniques that provide enhanced classification accuracy for breast tumor in the computer-aided B-mode ultrasound diagnosis system. To demonstrate the effectiveness of the proposed method, experiments were performed using 4,107 ultrasound images with 2,508 malignancy cases. Experimental results show that the breast tumor classification accuracy of the proposed technique was 15.8%, 5.43%, 17.32%, and 13.86% higher than the previous shape features such as number of protuberances, number of depressions, lobulation index, and dissimilarity, respectively.

  11. An Algorithm for Projecting Points onto a Patched CAD Model

    SciTech Connect

    Henshaw, W D

    2001-05-29

    We are interested in building structured overlapping grids for geometries defined by computer-aided-design (CAD) packages. Geometric information defining the boundary surfaces of a computation domain is often provided in the form of a collection of possibly hundreds of trimmed patches. The first step in building an overlapping volume grid on such a geometry is to build overlapping surface grids. A surface grid is typically built using hyperbolic grid generation; starting from a curve on the surface, a grid is grown by marching over the surface. A given hyperbolic grid will typically cover many of the underlying CAD surface patches. The fundamental operation needed for building surface grids is that of projecting a point in space onto the closest point on the CAD surface. We describe an fast algorithm for performing this projection, it will make use of a fairly coarse global triangulation of the CAD geometry. We describe how to build this global triangulation by first determining the connectivity of the CAD surface patches. This step is necessary since it often the case that the CAD description will contain no information specifying how a given patch connects to other neighboring patches. Determining the connectivity is difficult since the surface patches may contain mistakes such as gaps or overlaps between neighboring patches.

  12. Pattern classification of time plane features of ECG wave from cell-phone photography for machine aided cardiac disease diagnosis.

    PubMed

    Mitra, Rupendra Nath; Pramanik, Sayak; Mitra, Sucharita; Chaudhuri, Bidyut B

    2014-01-01

    This article reports a robust technique for extracting time plane features of Electrocardiogram (ECG) from digital images of ECG paper strips. We concluded this article reporting performance evaluation of the system developed for machine aided cardiac disease detection. Mostly paper based ECG recordings are used in developing countries and digital photographs of different leads could easily be taken and sent with a mediocre cellular phone set. Apart from extracting the features, the proposed system detects cardiac axis deviation and diagnose if Left or Right Bundle Branch Blockage (LBBB or RBBB) is present while fed with the digital photographs of different leads of ECG strips. Preprocessing of the low-resolution images involves background grid line noise removal, adaptive image binarization by Sauvola's method and Bresenham's line joining algorithm to link the ECG signature, if broken. Pattern extraction mainly delineate the time plane features like P wave, QRS complex and T wave using water reservoir based pattern recognition techniques and Discrete Wavelet Transform (DWT). Cardiac axis deviation detection is done by checking the overall voltage levels of QRS complexes of lead I, II and III. Having the knowledge of cardiac axis completes the requirements to comment on the cardiac blockage like Left or Right Bundle Branch Blockage (LBBB or RBBB). Thus, the proposed algorithm is primarily developed for machine aided diagnosis of LBBB or RBBB from the digital photographs of ECG paper strips. PMID:25571067

  13. Computer-aided diagnosis workstation and teleradiology network system for chest diagnosis using the web medical image conference system with a new information security solution

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kaneko, Masahiro; Kakinuma, Ryutaro; Moriyama, Noriyuki

    2010-03-01

    Diagnostic MDCT imaging requires a considerable number of images to be read. Moreover, the doctor who diagnoses a medical image is insufficient in Japan. Because of such a background, we have provided diagnostic assistance methods to medical screening specialists by developing a lung cancer screening algorithm that automatically detects suspected lung cancers in helical CT images, a coronary artery calcification screening algorithm that automatically detects suspected coronary artery calcification and a vertebra body analysis algorithm for quantitative evaluation of osteoporosis. We also have developed the teleradiology network system by using web medical image conference system. In the teleradiology network system, the security of information network is very important subjects. Our teleradiology network system can perform Web medical image conference in the medical institutions of a remote place using the web medical image conference system. We completed the basic proof experiment of the web medical image conference system with information security solution. We can share the screen of web medical image conference system from two or more web conference terminals at the same time. An opinion can be exchanged mutually by using a camera and a microphone that are connected with the workstation that builds in some diagnostic assistance methods. Biometric face authentication used on site of teleradiology makes "Encryption of file" and "Success in login" effective. Our Privacy and information security technology of information security solution ensures compliance with Japanese regulations. As a result, patients' private information is protected. Based on these diagnostic assistance methods, we have developed a new computer-aided workstation and a new teleradiology network that can display suspected lesions three-dimensionally in a short time. The results of this study indicate that our radiological information system without film by using computer-aided diagnosis

  14. The prediction of breast cancer biopsy outcomes using two CAD approaches that both emphasize an intelligible decision process

    SciTech Connect

    Elter, M.; Schulz-Wendtland, R.; Wittenberg, T.

    2007-11-15

    Mammography is the most effective method for breast cancer screening available today. However, the low positive predictive value of breast biopsy resulting from mammogram interpretation leads to approximately 70% unnecessary biopsies with benign outcomes. To reduce the high number of unnecessary breast biopsies, several computer-aided diagnosis (CAD) systems have been proposed in the last several years. These systems help physicians in their decision to perform a breast biopsy on a suspicious lesion seen in a mammogram or to perform a short term follow-up examination instead. We present two novel CAD approaches that both emphasize an intelligible decision process to predict breast biopsy outcomes from BI-RADS findings. An intelligible reasoning process is an important requirement for the acceptance of CAD systems by physicians. The first approach induces a global model based on decison-tree learning. The second approach is based on case-based reasoning and applies an entropic similarity measure. We have evaluated the performance of both CAD approaches on two large publicly available mammography reference databases using receiver operating characteristic (ROC) analysis, bootstrap sampling, and the ANOVA statistical significance test. Both approaches outperform the diagnosis decisions of the physicians. Hence, both systems have the potential to reduce the number of unnecessary breast biopsies in clinical practice. A comparison of the performance of the proposed decision tree and CBR approaches with a state of the art approach based on artificial neural networks (ANN) shows that the CBR approach performs slightly better than the ANN approach, which in turn results in slightly better performance than the decision-tree approach. The differences are statistically significant (p value <0.001). On 2100 masses extracted from the DDSM database, the CRB approach for example resulted in an area under the ROC curve of A(z)=0.89{+-}0.01, the decision-tree approach in A(z)=0

  15. Computer aided diagnosis of degenerative intervertebral disc diseases from lumbar MR images.

    PubMed

    Oktay, Ayse Betul; Albayrak, Nur Banu; Akgul, Yusuf Sinan

    2014-10-01

    This paper presents a novel method for the automated diagnosis of the degenerative intervertebral disc disease in midsagittal MR images. The approach is based on combining distinct disc features under a machine learning framework. The discs in the lumbar MR images are first localized and segmented. Then, intensity, shape, context, and texture features of the discs are extracted with various techniques. A Support Vector Machine classifier is applied to classify the discs as normal or degenerated. The method is tested and validated on a clinical lumbar spine dataset containing 102 subjects and the results are comparable to the state of the art.

  16. Computer aided diagnosis system for retinal analysis: automatic assessment of the vascular tortuosity.

    PubMed

    Sánchez, L; Barreira, N; Penedo, M G; Coll De Tuero, G

    2014-01-01

    The tortuosity of a vessel, that is, how many times a vessel curves, and how these turns are, is an important value for the diagnosis of certain diseases. Clinicians analyze fundus images manually in order to estimate it, but there is many drawbacks as it is a tedious, time-consuming and subjective work. Thus, automatic image processing methods become a necessity, as they make possible the efficient computation of objective parameters. In this paper we will discuss Sirius (System for the Integration of Retinal Images Understanding Service), a web-based application that enables the storage and treatment of various types of diagnostic tests and, more specifically, its tortuosity calculation module.

  17. CAD/CAM data management

    NASA Technical Reports Server (NTRS)

    Bray, O. H.

    1984-01-01

    The role of data base management in CAD/CAM, particularly for geometric data is described. First, long term and short term objectives for CAD/CAM data management are identified. Second, the benefits of the data base management approach are explained. Third, some of the additional work needed in the data base area is discussed.

  18. Cell sizing in chronic lymphoproliferative disorders: an aid to differential diagnosis.

    PubMed Central

    Alexander, H D; Markey, G M; Nolan, R L; Morris, T C

    1992-01-01

    AIMS: To determine if leucocyte volume distribution analysis (LVDA), obtained using a Coulter Counter Model S Plus IV, can be used to aid differentiation of chronic lymphoproliferative disorder (CLPD) subtypes. METHODS: Mean lymphocyte volume and lymphocyte distribution width were measured on each patient (n = 90) using a hard copy of an amplified LVDA histogram. The mean lymphocyte volume was taken as the mean of the values on either side of the peak at half maximum height. The lymphocyte distribution width was taken as the range of cell values between the two values used to calibrate the mean lymphocyte volume. A template showing typical histograms from commonly occurring CLPD was also produced on an acetate sheet. This was used to examine the histogram from each new patient to evaluate its usefulness as an alternative to the calculation of mean lymphocyte volume and lymphocyte distribution width. RESULTS: Mean lymphocyte volume and lymphocyte distribution width were significantly higher in B cell lymphocytic leukaemia of mixed cell type (B CLL/PL), B cell non-Hodgkin's lymphoma with peripheral blood spill, hairy cell leukaemia and T cell prolymphocytic leukaemia than in B cell chronic lymphocytic leukaemia (B CLL). The mean lymphocyte volume, but not the lymphocyte distribution width, was also significantly higher in T cell chronic lymphocytic leukaemia than in B CLL. The template gave an immediate preliminary indication of possible subtype(s) of disorder and could be used as an alternative to measurement of mean lymphocyte volume and lymphocyte distribution width. CONCLUSIONS: Electronic haematology analysers producing an LVDA provide a useful, cost effective cell sizing analysis which can aid the differentiation of subtypes of CLPD. Images PMID:1430257

  19. Mammographic computer-aided detection systems.

    PubMed

    2003-04-01

    While mammography is regarded as the best means available to screen for breast cancer, reading mammograms is a tedious, error-prone task. Given the repetitiveness of the process and the fact that less than 1% of mammograms in the average screening population contain cancer, it's no wonder that a significant number of breast cancers--about 28%--are missed by radiologists. The fact that human error is such a significant obstacle makes mammography screening an ideal application for computer-aided detection (CAD) systems. CAD systems serve as a "second pair of eyes" to ensure that radiologists don't miss a suspect area on an image. They analyze patterns on a digitized mammographic image, identify regions that may contain an abnormality indicating cancer, and mark these regions. The marks are then inspected and classified by a radiologist. But CAD systems provide no diagnosis of any kind--it's up to the radiologist to analyze the marked area and decide if it shows cancer. In this Evaluation, we describe the challenges posed by screening mammography, the operating principles and overall efficacy of CAD systems, and the characteristics to consider when purchasing a system. We also compare the performance of two commercially available systems, iCAD's MammoReader and R2's ImageChecker. Because the two systems offer comparable sensitivity, our judgments are based on other performance characteristics, including their ease of use, the number of false marks they produce, the degree to which they can integrate with hospital information systems, and their processing speed.

  20. Fuzzy Computer-Aided Alzheimer's Disease Diagnosis Based on MRI Data.

    PubMed

    Krashenyi, Igor; Ramírez, Javier; Popov, Anton; Górriz, Juan Manuel; The Alzheimer's Disease Neuroimaging Initiative

    2016-01-01

    Alzheimer's disease (AD) is a chronic neurodegenerative disease of the central nervous system that has no cure and leads to death. One of the most prevalent tools for AD diagnosis is magnetic resonance imaging (MRI), because of its capability to visualize brain anatomical structures. There is a variety of classification methods for automatic diagnosis of AD, such as support vector machines, genetic algorithms, Bayes classifiers, neural networks, random forests, etc., but none of them provides robust information about the stage of the AD, they can just reveal the presence of disease. In this paper, a new approach for classification of MRI images using a fuzzy inference system is proposed. Two statistical moments (mean and standard deviation) of 116 anatomical regions of interests (ROIs) are used as input features for the classification system. A t-test feature selection method is used to identify the most discriminative ROIs. In order to evaluate the proposed system, MRI images from a database consisting of 818 subjects (229 normal, 401 mild cognitive impairment and 188 AD subjects) collected from the Alzheimer's disease neuroimaging initiative (ADNI) is analyzed. The receiver operating characteristics (ROC) curve and the area under the curve (AUC) of the proposed fuzzy inference system fed by statistical input features are employed as the evaluation criteria with k-fold cross validation. The proposed system yields promising results in normal vs. AD classification with AUC of 0.99 on the training set and 0.8622±0.0033 on the testing set. PMID:26971942

  1. Computer-Aided Diagnosis of Micro-Malignant Melanoma Lesions Applying Support Vector Machines.

    PubMed

    Jaworek-Korjakowska, Joanna

    2016-01-01

    Background. One of the fatal disorders causing death is malignant melanoma, the deadliest form of skin cancer. The aim of the modern dermatology is the early detection of skin cancer, which usually results in reducing the mortality rate and less extensive treatment. This paper presents a study on classification of melanoma in the early stage of development using SVMs as a useful technique for data classification. Method. In this paper an automatic algorithm for the classification of melanomas in their early stage, with a diameter under 5 mm, has been presented. The system contains the following steps: image enhancement, lesion segmentation, feature calculation and selection, and classification stage using SVMs. Results. The algorithm has been tested on 200 images including 70 melanomas and 130 benign lesions. The SVM classifier achieved sensitivity of 90% and specificity of 96%. The results indicate that the proposed approach captured most of the malignant cases and could provide reliable information for effective skin mole examination. Conclusions. Micro-melanomas due to the small size and low advancement of development create enormous difficulties during the diagnosis even for experts. The use of advanced equipment and sophisticated computer systems can help in the early diagnosis of skin lesions. PMID:27382567

  2. Computer-aided design of peptide near infrared fluorescent probe for tumor diagnosis

    NASA Astrophysics Data System (ADS)

    Zhang, Congying; Gu, Yueqing

    2014-09-01

    Integrin αvβ3 receptors are expressed on activated endothelial cells during neovascularization to maintain tumor growth, so they become hot research tagets in cancer diagnosis. Peptides possess several attractive features when compared to protein and small molecule, such as small size and high structural compatibility with target proteins. Efficient design of high-affinity peptide ligands to Integrin αvβ3 receptors has been an important problem. Designed peptides in silico provide a valuable and high-selectivity peptide, meanwhile decrease the time of drug screening. In this study, we design peptide which can bind with integrin αvβ3 via computer, and then synthesis near infrared fluorescent probe. The characterization of this near infrared fluorescent probe was detected by UV. To investigate the tumor cell targeting of this probe, it was labeled with visible fluorescent dye Rhodamine B (RhB) for microscopy. To evaluate the targeting capability of this near infrared fluorescent probe, mice bearing integrin αvβ3 positive tumor xenografts were used. In vitro cellular experiments indicated that this probe have a clear binding affinity to αvβ3-positive tumor cells. In vivo experiments confirmed the receptor binding specificity of this probe. The peptide of computational design can bind with integrin αvβ3. Combined peptide near-infrared fluorescent probe with imaging technology use for clinical and tumor diagnosis have a greater development in future.

  3. Computer-Aided Diagnosis of Micro-Malignant Melanoma Lesions Applying Support Vector Machines

    PubMed Central

    2016-01-01

    Background. One of the fatal disorders causing death is malignant melanoma, the deadliest form of skin cancer. The aim of the modern dermatology is the early detection of skin cancer, which usually results in reducing the mortality rate and less extensive treatment. This paper presents a study on classification of melanoma in the early stage of development using SVMs as a useful technique for data classification. Method. In this paper an automatic algorithm for the classification of melanomas in their early stage, with a diameter under 5 mm, has been presented. The system contains the following steps: image enhancement, lesion segmentation, feature calculation and selection, and classification stage using SVMs. Results. The algorithm has been tested on 200 images including 70 melanomas and 130 benign lesions. The SVM classifier achieved sensitivity of 90% and specificity of 96%. The results indicate that the proposed approach captured most of the malignant cases and could provide reliable information for effective skin mole examination. Conclusions. Micro-melanomas due to the small size and low advancement of development create enormous difficulties during the diagnosis even for experts. The use of advanced equipment and sophisticated computer systems can help in the early diagnosis of skin lesions. PMID:27382567

  4. New genomic technologies: an aid for diagnosis of disorders of sex development.

    PubMed

    Barseghyan, H; Délot, E; Vilain, E

    2015-05-01

    The Chicago Consensus Conference of 2005 defined Disorders of Sex Development (DSD) as "congenital conditions in which the development of chromosomal, gonadal or anatomic sex is atypical." DSD diagnoses are difficult to establish. A lack of standardization of anatomical and endocrine phenotyping and the limited number of known DSD genes and genotype/correlation has long hampered the field, leaving many patients without a definitive diagnosis. The resulting uncertainty may intrinsically pose a great amount of discomfort to affected individuals and their families. DSD-causative genes have historically been identified thanks to positional cloning of disease-associated variants segregating in families or chromosomal rearrangements. Recent advances of chromosomal microarray and exome sequencing technologies are allowing for higher rates of diagnostic success for DSD patients and are changing clinical practice. In this review, we discuss the application of these technologies and their findings as an upcoming model for clinical diagnosis of DSD. We show that exome sequencing is a valuable tool and we propose that it should be used as a first-stage diagnostic technique because it allows for early identification of a genetic cause that may be critical for patient management.

  5. Predictive deconvolution and hybrid feature selection for computer-aided detection of prostate cancer.

    PubMed

    Maggio, Simona; Palladini, Alessandro; Marchi, Luca De; Alessandrini, Martino; Speciale, Nicolò; Masetti, Guido

    2010-02-01

    Computer-aided detection (CAD) schemes are decision making support tools, useful to overcome limitations of problematic clinical procedures. Trans-rectal ultrasound image based CAD would be extremely important to support prostate cancer diagnosis. An effective approach to realize a CAD scheme for this purpose is described in this work, employing a multi-feature kernel classification model based on generalized discriminant analysis. The mutual information of feature value and tissue pathological state is used to select features essential for tissue characterization. System-dependent effects are reduced through predictive deconvolution of the acquired radio-frequency signals. A clinical study, performed on ground truth images from biopsy findings, provides a comparison of the classification model applied before and after deconvolution, showing in the latter case a significant gain in accuracy and area under the receiver operating characteristic curve.

  6. Time to HAART Initiation after Diagnosis and Treatment of Opportunistic Infections in Patients with AIDS in Latin America

    PubMed Central

    Crabtree-Ramírez, Brenda; Caro-Vega, Yanink; Shepherd, Bryan E.; Grinsztejn, Beatriz; Wolff, Marcelo; Cortes, Claudia P.; Padgett, Denis; Carriquiry, Gabriela; Fink, Valeria; Jayathilake, Karu; Person, Anna K.; McGowan, Catherine; Sierra-Madero, Juan

    2016-01-01

    Background Since 2009, earlier initiation of highly active antiretroviral therapy (HAART) after an opportunistic infection (OI) has been recommended based on lower risks of death and AIDS-related progression found in clinical trials. Delay in HAART initiation after OIs may be an important barrier for successful outcomes in patients with advanced disease. Timing of HAART initiation after an OI in “real life” settings in Latin America has not been evaluated. Methods Patients in the Caribbean, Central and South America network for HIV Epidemiology (CCASAnet) ≥18 years of age at enrolment, from 2001–2012 who had an OI before HAART initiation were included. Patients were divided in an early HAART (EH) group (those initiating within 4 weeks of an OI) and a delayed HAART (DH) group (those initiating more than 4 weeks after an OI). All patients with an AIDS-defining OI were included. In patients with more than one OI the first event reported was considered. Calendar trends in the proportion of patients in the EH group (before and after 2009) were estimated by site and for the whole cohort. Factors associated with EH were estimated using multivariable logistic regression models. Results A total of 1457 patients had an OI before HAART initiation and were included in the analysis: 213 from Argentina, 686 from Brazil, 283 from Chile, 119 from Honduras and 156 from Mexico. Most prevalent OI were Tuberculosis (31%), followed by Pneumocystis pneumonia (24%), Invasive Candidiasis (16%) and Toxoplasmosis (9%). Median time from OI to HAART initiation decreased significantly from 5.7 (interquartile range [IQR] 2.8–12.1) weeks before 2009 to 4.3 (IQR 2.0–7.1) after 2009 (p<0.01). Factors associated with starting HAART within 4 weeks of OI diagnosis were lower CD4 count at enrolment (p-<0.001), having a non-tuberculosis OI (p<0.001), study site (p<0.001), and more recent years of OI diagnosis (p<0.001). Discussion The time from diagnosis of an OI to HAART initiation has

  7. Standardized evaluation of algorithms for computer-aided diagnosis of dementia based on structural MRI: the CADDementia challenge.

    PubMed

    Bron, Esther E; Smits, Marion; van der Flier, Wiesje M; Vrenken, Hugo; Barkhof, Frederik; Scheltens, Philip; Papma, Janne M; Steketee, Rebecca M E; Méndez Orellana, Carolina; Meijboom, Rozanna; Pinto, Madalena; Meireles, Joana R; Garrett, Carolina; Bastos-Leite, António J; Abdulkadir, Ahmed; Ronneberger, Olaf; Amoroso, Nicola; Bellotti, Roberto; Cárdenas-Peña, David; Álvarez-Meza, Andrés M; Dolph, Chester V; Iftekharuddin, Khan M; Eskildsen, Simon F; Coupé, Pierrick; Fonov, Vladimir S; Franke, Katja; Gaser, Christian; Ledig, Christian; Guerrero, Ricardo; Tong, Tong; Gray, Katherine R; Moradi, Elaheh; Tohka, Jussi; Routier, Alexandre; Durrleman, Stanley; Sarica, Alessia; Di Fatta, Giuseppe; Sensi, Francesco; Chincarini, Andrea; Smith, Garry M; Stoyanov, Zhivko V; Sørensen, Lauge; Nielsen, Mads; Tangaro, Sabina; Inglese, Paolo; Wachinger, Christian; Reuter, Martin; van Swieten, John C; Niessen, Wiro J; Klein, Stefan

    2015-05-01

    Algorithms for computer-aided diagnosis of dementia based on structural MRI have demonstrated high performance in the literature, but are difficult to compare as different data sets and methodology were used for evaluation. In addition, it is unclear how the algorithms would perform on previously unseen data, and thus, how they would perform in clinical practice when there is no real opportunity to adapt the algorithm to the data at hand. To address these comparability, generalizability and clinical applicability issues, we organized a grand challenge that aimed to objectively compare algorithms based on a clinically representative multi-center data set. Using clinical practice as the starting point, the goal was to reproduce the clinical diagnosis. Therefore, we evaluated algorithms for multi-class classification of three diagnostic groups: patients with probable Alzheimer's disease, patients with mild cognitive impairment and healthy controls. The diagnosis based on clinical criteria was used as reference standard, as it was the best available reference despite its known limitations. For evaluation, a previously unseen test set was used consisting of 354 T1-weighted MRI scans with the diagnoses blinded. Fifteen research teams participated with a total of 29 algorithms. The algorithms were trained on a small training set (n=30) and optionally on data from other sources (e.g., the Alzheimer's Disease Neuroimaging Initiative, the Australian Imaging Biomarkers and Lifestyle flagship study of aging). The best performing algorithm yielded an accuracy of 63.0% and an area under the receiver-operating-characteristic curve (AUC) of 78.8%. In general, the best performances were achieved using feature extraction based on voxel-based morphometry or a combination of features that included volume, cortical thickness, shape and intensity. The challenge is open for new submissions via the web-based framework: http://caddementia.grand-challenge.org.

  8. A novel supervised approach for segmentation of lung parenchyma from chest CT for computer-aided diagnosis.

    PubMed

    Darmanayagam, Shiloah Elizabeth; Harichandran, Khanna Nehemiah; Cyril, Sunil Retmin Raj; Arputharaj, Kannan

    2013-06-01

    Segmentation of lung parenchyma from the chest computed tomography is an important task in analysis of chest computed tomography for diagnosis of lung disorders. It is a challenging task especially in the presence of peripherally placed pathology bearing regions. In this work, we propose a segmentation approach to segment lung parenchyma from chest. The first step is to segment the lungs using iterative thresholding followed by morphological operations. If the two lungs are not separated, the lung junction and its neighborhood are identified and local thresholding is applied. The second step is to extract shape features of the two lungs. The third step is to use a multilayer feed forward neural network to determine if the segmented lung parenchyma is complete, based on the extracted features. The final step is to reconstruct the two lungs in case of incomplete segmentation, by exploiting the fact that in majority of the cases, at least one of the two lungs would have been segmented correctly by the first step. Hence, the complete lung is determined based on the shape and region properties and the incomplete lung is reconstructed by applying graphical methods, namely, reflection and translation. The proposed approach has been tested in a computer-aided diagnosis system for diagnosis of lung disorders, namely, bronchiectasis, tuberculosis, and pneumonia. An accuracy of 97.37 % has been achieved by the proposed approach whereas the conventional thresholding approach was unable to detect peripheral pathology-bearing regions. The results obtained prove to be better than that achieved using conventional thresholding and morphological operations. PMID:23076539

  9. Lung partitioning for x-ray CAD applications

    NASA Astrophysics Data System (ADS)

    Annangi, Pavan; Raja, Anand

    2011-03-01

    Partitioning the inside region of lung into homogeneous regions becomes a crucial step in any computer-aided diagnosis applications based on chest X-ray. The ribs, air pockets and clavicle occupy major space inside the lung as seen in the chest x-ray PA image. Segmenting the ribs and clavicle to partition the lung into homogeneous regions forms a crucial step in any CAD application to better classify abnormalities. In this paper we present two separate algorithms to segment ribs and the clavicle bone in a completely automated way. The posterior ribs are segmented based on Phase congruency features and the clavicle is segmented using Mean curvature features followed by Radon transform. Both the algorithms work on the premise that the presentation of each of these anatomical structures inside the left and right lung has a specific orientation range within which they are confined to. The search space for both the algorithms is limited to the region inside the lung, which is obtained by an automated lung segmentation algorithm that was previously developed in our group. Both the algorithms were tested on 100 images of normal and patients affected with Pneumoconiosis.

  10. Visualizing request-flow comparison to aid performance diagnosis in distributed systems.

    PubMed

    Sambasivan, Raja R; Shafer, Ilari; Mazurek, Michelle L; Ganger, Gregory R

    2013-12-01

    Distributed systems are complex to develop and administer, and performance problem diagnosis is particularly challenging. When performance degrades, the problem might be in any of the system's many components or could be a result of poor interactions among them. Recent research efforts have created tools that automatically localize the problem to a small number of potential culprits, but research is needed to understand what visualization techniques work best for helping distributed systems developers understand and explore their results. This paper compares the relative merits of three well-known visualization approaches (side-by-side, diff, and animation) in the context of presenting the results of one proven automated localization technique called request-flow comparison. Via a 26-person user study, which included real distributed systems developers, we identify the unique benefits that each approach provides for different problem types and usage modes. PMID:24051813

  11. How to Quickly Import CAD Geometry into Thermal Desktop

    NASA Astrophysics Data System (ADS)

    Wright, Shonte; Beltran, Emilio

    2002-07-01

    There are several groups at JPL (Jet Propulsion Laboratory) that are committed to concurrent design efforts, two are featured here. Center for Space Mission Architecture and Design (CSMAD) enables the practical application of advanced process technologies in JPL's mission architecture process. Team I functions as an incubator for projects that are in the Discovery, and even pre-Discovery proposal stages. JPL's concurrent design environment is to a large extent centered on the CAD (Computer Aided Design) file. During concurrent design sessions CAD geometry is ported to other more specialized engineering design packages.

  12. Construction CAE; Integration of CAD, simulation, planning and cost control

    SciTech Connect

    Wickard, D.A. ); Bill, R.D.; Gates, K.H.; Yoshinaga, T.; Ohcoshi, S. )

    1989-01-01

    Construction CAE is a simulation, planning, scheduling, and cost control tool that is integrated with a computer aided design (CAD) system. The system uses a CAD model and allows the user to perform construction simulation on objects defined within the model. Initial cost/schedule reports as well as those required for project chronicling are supported through an interface to a work breakdown structure (WBS) and a client's existing schedule reporting system. By integrating currently available project control tools with a simulation system, Construction CAE is more effective than its individual components.

  13. Computer-aided differential diagnosis of pulmonary nodules based on a hybrid classification approach

    NASA Astrophysics Data System (ADS)

    Kawata, Yoshiki; Niki, Noboru; Omatsu, Hironobu; Kusumoto, Masahiko; Kakinuma, Ryutaro; Mori, Kiyoshi; Nishiyama, Hiroyuki; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki

    2001-07-01

    We are developing computerized feature extraction and classification methods to analyze malignant and benign pulmonary nodules in 3D thoracic CT images. Internal structure features were derived form CT density and 3D curvatures to characterize the inhomogeneous of CT density distribution inside the nodule. In the classification step, we combined an unsupervised k-means clustering (KMC) procedure and a supervised linear discriminate (LD) classifier. The KMC procedure classified the sample nodules into two classes by using the mean CT density values for two different regions such as a core region and a complement of the core region in 3D nodule image. The LD classifier was designed for each class by using internal structure features. The forward stepwise procedure was used to select the best feature subset from multi-dimensional feature spaces. The discriminant scores output form the classifier were analyzed by receiver operating characteristic (ROC) method and the classification accuracy was quantified by the area, Ax, under the ROC curve. We analyzed a data set of 248 pulmonary nodules in this study. The hybrid classifier was more effective than the LD classifier alone in distinguishing malignant and benign nodules. The improvement was statistically significant in comparison to classification in the LD classifier alone. The results of this study indicate the potential of combining the KMC procedure and the LD classifier for computer-aided classification of pulmonary nodules.

  14. An intelligent pre-processing framework for standardizing medical images for CAD and other post-processing applications

    NASA Astrophysics Data System (ADS)

    Raghupathi, Lakshminarasimhan; Devarakota, Pandu R.; Wolf, Matthias

    2012-03-01

    There is an increasing need to provide end-users with seamless and secure access to healthcare information acquired from a diverse range of sources. This might include local and remote hospital sites equipped with different vendors and practicing varied acquisition protocols and also heterogeneous external sources such as the Internet cloud. In such scenarios, image post-processing tools such as CAD (computer-aided diagnosis) which were hitherto developed using a smaller set of images may not always work optimally on newer set of images having entirely different characteristics. In this paper, we propose a framework that assesses the quality of a given input image and automatically applies an appropriate pre-processing method in such a manner that the image characteristics are normalized regardless of its source. We focus mainly on medical images, and the objective of the said preprocessing method is to standardize the performance of various image processing and workflow applications like CAD to perform in a consistent manner. First, our system consists of an assessment step wherein an image is evaluated based on criteria such as noise, image sharpness, etc. Depending on the measured characteristic, we then apply an appropriate normalization technique thus giving way to our overall pre-processing framework. A systematic evaluation of the proposed scheme is carried out on large set of CT images acquired from various vendors including images reconstructed with next generation iterative methods. Results demonstrate that the images are normalized and thus suitable for an existing LungCAD prototype1.

  15. Towards the routine use of brain imaging to aid the clinical diagnosis of disorders of consciousness.

    PubMed

    Coleman, M R; Davis, M H; Rodd, J M; Robson, T; Ali, A; Owen, A M; Pickard, J D

    2009-09-01

    Clinical audits have highlighted the many challenges and dilemmas faced by clinicians assessing persons with disorders of consciousness (vegetative state and minimally conscious state). The diagnostic decision-making process is highly subjective, dependent upon the skills of the examiner and invariably dictated by the patients' ability to move or speak. Whilst a considerable amount has been learnt since Jennett and Plum coined the term 'vegetative state', the assessment process remains largely unchanged; conducted at the bedside, using behavioural assessment tools, which are susceptible to environmental and physiological factors. This has created a situation where the rate of misdiagnosis is unacceptably high (up to 43%). In order to address these problems, various functional brain imaging paradigms, which do not rely upon the patient's ability to move or speak, have been proposed as a source of additional information to inform the diagnostic decision making process. Although accumulated evidence from brain imaging, particularly functional magnetic resonance imaging (fMRI), has been encouraging, the empirical evidence is still based on relatively small numbers of patients. It remains unclear whether brain imaging is capable of informing the diagnosis beyond the behavioural assessment and whether brain imaging has any prognostic utility. In this study, we describe the functional brain imaging findings from a group of 41 patients with disorders of consciousness, who undertook a hierarchical speech processing task. We found, contrary to the clinical impression of a specialist team using behavioural assessment tools, that two patients referred to the study with a diagnosis of vegetative state did in fact demonstrate neural correlates of speech comprehension when assessed using functional brain imaging. These fMRI findings were found to have no association with the patient's behavioural presentation at the time of investigation and thus provided additional diagnostic

  16. Performance evaluation of the NASA/KSC CAD/CAE and office automation LAN's

    NASA Technical Reports Server (NTRS)

    Zobrist, George W.

    1994-01-01

    This study's objective is the performance evaluation of the existing CAD/CAE (Computer Aided Design/Computer Aided Engineering) network at NASA/KSC. This evaluation also includes a similar study of the Office Automation network, since it is being planned to integrate this network into the CAD/CAE network. The Microsoft mail facility which is presently on the CAD/CAE network was monitored to determine its present usage. This performance evaluation of the various networks will aid the NASA/KSC network managers in planning for the integration of future workload requirements into the CAD/CAE network and determining the effectiveness of the planned FDDI (Fiber Distributed Data Interface) migration.

  17. Computer-aided clinical laboratory diagnosis in conjunction with the electronic medical textbook.

    PubMed

    Kawamata, F; Kondoh, M; Mori, C; Endoh, J; Takahashi, T

    1995-01-01

    1. INTRODUCTION. Medical knowledge has been increasing and diversifying on a worldwide scale, while the specialization of physicians has been extended vigorously. Under this environment, it may be natural that mistakes are made in a comprehensive diagnosis, as the physician cannot master all of this dramatically increasing volume of knowledge. The knowledge has extended beyond the memory of human beings, thereby causing the deterioration of service; this is called the "Knowledge crisis." To tackle this problem, the Electronic Medical Textbook (EMT) has been conceived and set up as a medical knowledge base for physicians to optimize both their specialties and activities in clinical practice. Meanwhile, laboratory information systems were widely introduced. However, there are few systems which allow interpretation of the findings obtained. With this in mind, we have improved the utility of the EMT by enhancing its function with laboratory information follow-up, thesaurus back-up, Japanese language support, and online access. 2. SYSTEM DESCRIPTION. The knowledge database for medical decision-making consists of three categories: 1) Medical domain knowledge (including approximately 3500 diseases) from the AMA's "The Current Medical Information & Terminology (CMIT)"; 2) Knowledge on relationship between laboratory testing results and diseases from "The Effects of Disease on Clinical Laboratory," compiled by the AACC; and 3) Clinical testing knowledge from Otsuka's laboratory test handbook "Kensa-Kojien." These categories are connected by links in the process of cross-reference. In actual use, the first is to select the supporting system bringing up clinical signs and findings on CRT from which users can then choose any representations corresponding to the patient's clinical state. Once the relevant objects have been selected, the system presents the correlated investigative tests to be performed, along with a scope of laboratory tests ordering for its initial

  18. Computer-aided diagnosis for prostate cancer detection in the peripheral zone via multisequence MRI

    NASA Astrophysics Data System (ADS)

    Niaf, Emilie; Rouvière, Olivier; Lartizien, Carole

    2011-03-01

    We propose a Computer Assisted Diagnosis Interview (CADi) scheme for determining a likelihood measure of prostate cancer presence in the peripheral zone (PZ) based on multisequence magnetic resonance imaging, including T2-weighted (T2w), diffusion-weighted (DWI) and dynamic contrast-enhanced (DCE) MRI at 1.5 Tesla (T). Based on a feature set derived from the gray level images, including first order statistics, Haralick's features, gradient features, semi-quantitative and quantitative (pharmacokinetic modeling) dynamic parameters, we trained and compared four kinds of classifiers: Support Vector Machine (SVM), Linear Discriminant Analysis (LDA), k-Nearest Neighbours (KNN) and Naïve Bayes (NB). The aim is twofold: we try to discriminate between the relevant features as well as creating an efficient classifier using these features. The database consists of 23 radical prostatectomy patients. Using histologic sections as the gold standard, both cancers and non-malignant tissues (suspicious and clearly benign) were annotated in consensus on all MR images by two radiologists, a histopathologist and a researcher. Diagnostic performances were evaluated based on a ROC curves analysis. From the outputs of all evaluated feature selection methods on the test bench, we discriminated a restrictive set of about 20 highly informative features. Quantitative evaluation of the diagnostic performance yielded to a maximal Area Under the ROC Curve (AUC) of 0.89. Moreover, the optimal CADi scheme outperformed, in terms of specificity, our human experts in differentiating malignant from suspicious tissues, thus demonstrating its potential for assisting cancer identification in the PZ.

  19. Computed tomography--a possible aid in the diagnosis of smoke inhalation injury?

    PubMed

    Reske, A; Bak, Z; Samuelsson, A; Morales, O; Seiwerts, M; Sjöberg, F

    2005-02-01

    Inhalation injury is an important contributor to morbidity and mortality in burn victims and can trigger acute lung injury and acute respiratory distress syndrome (ARDS) (1-3). Early diagnosis and treatment of inhalation injury are important, but a major problem in planning treatment and evaluating the prognosis has been the lack of consensus about diagnostic criteria (4). Chest radiographs on admission are often non-specific (5, 6), but indicators include indoor fires, facial burns, bronchoscopic findings of soot in the airways, and detection of carbon monoxide or cyanide in the blood (7). Changes in the lungs may be detected by bronchoscopy with biopsy, xenon imaging, or measurement of pulmonary extracellular fluid (4, 5, 8). These methods have, however, been associated with low sensitivity and specificity, as exemplified by the 50% predictive value in the study of Masanes et al. (8). Computed tomographs (CTs) are better than normal chest radiographs in the detection of other pulmonary lesions such as pulmonary contusion (9, 10). The importance of CT scans in patients with ARDS has been reviewed recently (9), but unfortunately there has been no experience of CT in patients with smoke inhalation injury. To our knowledge, there are only two animal studies reporting that smoke inhalation injury can be detected by CT (4, 11); specific changes in human CT scans have not yet been described. Therefore, confronted with a patient with severe respiratory failure after a burn who from the history and physical examination showed the classic risk factors for inhalation injury, we decided to request a CT. PMID:15715631

  20. Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

    PubMed Central

    Kwon, Taek-Ka; Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns. RESULTS The mean fracture strengths were as follows: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain. CONCLUSION The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain. PMID:23755332

  1. Computer-aided diagnosis of prostate cancer in the peripheral zone using multiparametric MRI

    NASA Astrophysics Data System (ADS)

    Niaf, Emilie; Rouvière, Olivier; Mège-Lechevallier, Florence; Bratan, Flavie; Lartizien, Carole

    2012-06-01

    This study evaluated a computer-assisted diagnosis (CADx) system for determining a likelihood measure of prostate cancer presence in the peripheral zone (PZ) based on multiparametric magnetic resonance (MR) imaging, including T2-weighted, diffusion-weighted and dynamic contrast-enhanced MRI at 1.5 T. Based on a feature set derived from grey-level images, including first-order statistics, Haralick features, gradient features, semi-quantitative and quantitative (pharmacokinetic modelling) dynamic parameters, four kinds of classifiers were trained and compared : nonlinear support vector machine (SVM), linear discriminant analysis, k-nearest neighbours and naïve Bayes classifiers. A set of feature selection methods based on t-test, mutual information and minimum-redundancy-maximum-relevancy criteria were also compared. The aim was to discriminate between the relevant features as well as to create an efficient classifier using these features. The diagnostic performances of these different CADx schemes were evaluated based on a receiver operating characteristic (ROC) curve analysis. The evaluation database consisted of 30 sets of multiparametric MR images acquired from radical prostatectomy patients. Using histologic sections as the gold standard, both cancer and nonmalignant (but suspicious) tissues were annotated in consensus on all MR images by two radiologists, a histopathologist and a researcher. Benign tissue regions of interest (ROIs) were also delineated in the remaining prostate PZ. This resulted in a series of 42 cancer ROIs, 49 benign but suspicious ROIs and 124 nonsuspicious benign ROIs. From the outputs of all evaluated feature selection methods on the test bench, a restrictive set of about 15 highly informative features coming from all MR sequences was discriminated, thus confirming the validity of the multiparametric approach. Quantitative evaluation of the diagnostic performance yielded a maximal area under the ROC curve (AUC) of 0.89 (0.81-0.94) for the

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

    NASA Astrophysics Data System (ADS)

    Cerello, Piergiorgio; MAGIC-5 Collaboration

    2010-11-01

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

  3. Preliminary investigation on CAD system update: effect of selection of new cases on classifier performance

    NASA Astrophysics Data System (ADS)

    Muramatsu, Chisako; Nishimura, Kohei; Hara, Takeshi; Fujita, Hiroshi

    2013-02-01

    When a computer-aided diagnosis (CAD) system is used in clinical practice, it is desirable that the system is constantly and automatically updated with new cases obtained for performance improvement. In this study, the effect of different case selection methods for the system updates was investigated. For the simulation, the data for classification of benign and malignant masses on mammograms were used. Six image features were used for training three classifiers: linear discriminant analysis (LDA), support vector machine (SVM), and k-nearest neighbors (kNN). Three datasets, including dataset I for initial training of the classifiers, dataset T for intermediate testing and retraining, and dataset E for evaluating the classifiers, were randomly sampled from the database. As a result of intermediate testing, some cases from dataset T were selected to be added to the previous training set in the classifier updates. In each update, cases were selected using 4 methods: selection of (a) correctly classified samples, (b) incorrectly classified samples, (c) marginally classified samples, and (d) random samples. For comparison, system updates using all samples in dataset T were also evaluated. In general, the average areas under the receiver operating characteristic curves (AUCs) were almost unchanged with method (a), whereas AUCs generally degraded with method (b). The AUCs were improved with method (c) and (d), although use of all available cases generally provided the best or nearly best AUCs. In conclusion, CAD systems may be improved by retraining with new cases accumulated during practice.

  4. Mortality of the elderly is still exceedingly high at diagnosis of AIDS despite favourable outcomes after highly active antiretroviral therapy in Recife, Brazil.

    PubMed

    Lacerda, H R; Kitner, D

    2008-07-01

    This study aimed to compare the outcome of an elderly group of AIDS patients with that of a younger group and their features at the time of the diagnosis of AIDS. We evaluated 58 patients aged >60 years and 114 aged 20-39 years, followed for 35.3 months. There was an obvious delay in diagnosing the elderly as they had more AIDS-defining diseases at diagnosis and their most frequent opportunistic infection was pulmonary tuberculosis. Mortality at the time of the diagnosis of AIDS was four times higher in the elderly (24.1% versus 6.1%, P < 0.001). However, when comparing only those submitted to highly active antiretroviral therapy, there was a similar frequency of favourable outcomes; 76.9% in the elderly against 83.1% in the young (P = 0.455). Mean CD4 lymphocyte was 438 cells/mm(3) at the end of follow up in the young when compared with 442 cells/mm(3) in the elderly (P = 0.945). The types of antiretroviral schema and the number of antivirals per patient were similar in both groups.

  5. An integrated classifier for computer-aided diagnosis of colorectal polyps based on random forest and location index strategies

    NASA Astrophysics Data System (ADS)

    Hu, Yifan; Han, Hao; Zhu, Wei; Li, Lihong; Pickhardt, Perry J.; Liang, Zhengrong

    2016-03-01

    Feature classification plays an important role in differentiation or computer-aided diagnosis (CADx) of suspicious lesions. As a widely used ensemble learning algorithm for classification, random forest (RF) has a distinguished performance for CADx. Our recent study has shown that the location index (LI), which is derived from the well-known kNN (k nearest neighbor) and wkNN (weighted k nearest neighbor) classifier [1], has also a distinguished role in the classification for CADx. Therefore, in this paper, based on the property that the LI will achieve a very high accuracy, we design an algorithm to integrate the LI into RF for improved or higher value of AUC (area under the curve of receiver operating characteristics -- ROC). Experiments were performed by the use of a database of 153 lesions (polyps), including 116 neoplastic lesions and 37 hyperplastic lesions, with comparison to the existing classifiers of RF and wkNN, respectively. A noticeable gain by the proposed integrated classifier was quantified by the AUC measure.

  6. Computer-aided diagnosis system for classifying benign and malignant thyroid nodules in multi-stained FNAB cytological images.

    PubMed

    Gopinath, Balasubramanian; Shanthi, Natesan

    2013-06-01

    An automated computer-aided diagnosis system is developed to classify benign and malignant thyroid nodules using multi-stained fine needle aspiration biopsy (FNAB) cytological images. In the first phase, the image segmentation is performed to remove the background staining information and retain the appropriate foreground cell objects in cytological images using mathematical morphology and watershed transform segmentation methods. Subsequently, statistical features are extracted using two-level discrete wavelet transform (DWT) decomposition, gray level co-occurrence matrix (GLCM) and Gabor filter based methods. The classifiers k-nearest neighbor (k-NN), Elman neural network (ENN) and support vector machine (SVM) are tested for classifying benign and malignant thyroid nodules. The combination of watershed segmentation, GLCM features and k-NN classifier results a lowest diagnostic accuracy of 60 %. The highest diagnostic accuracy of 93.33 % is achieved by ENN classifier trained with the statistical features extracted by Gabor filter bank from the images segmented by morphology and watershed transform segmentation methods. It is also observed that SVM classifier results its highest diagnostic accuracy of 90 % for DWT and Gabor filter based features along with morphology and watershed transform segmentation methods. The experimental results suggest that the developed system with multi-stained thyroid FNAB images would be useful for identifying thyroid cancer irrespective of staining protocol used.

  7. A completely automated CAD system for mass detection in a large mammographic database

    SciTech Connect

    Bellotti, R.; De Carlo, F.; Tangaro, S.

    2006-08-15

    Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing second-order spatial statistics information on the pixel gray level intensity. As the images under study were recorded in different centers and with different machine settings, eight GTSDM features were selected so as to be invariant under monotonic transformation. In this way, the images do not need to be normalized, as the adopted features depend on the texture only, rather than on the gray tone levels, too. (c) ROI classification by means of a neural network, with supervision provided by the radiologist's diagnosis. The CAD system was evaluated on a large database of 3369 mammographic images [2307 negative, 1062 pathological (or positive), containing at least one confirmed mass, as diagnosed by an expert radiologist]. To assess the performance of the system, receiver operating characteristic (ROC) and free-response ROC analysis were employed. The area under the ROC curve was found to be A{sub z}=0.783{+-}0.008 for the ROI-based classification. When evaluating the accuracy of the CAD against the radiologist-drawn boundaries, 4.23 false positives per image are found at 80% of mass sensitivity.

  8. An Educational Exercise Examining the Role of Model Attributes on the Creation and Alteration of CAD Models

    ERIC Educational Resources Information Center

    Johnson, Michael D.; Diwakaran, Ram Prasad

    2011-01-01

    Computer-aided design (CAD) is a ubiquitous tool that today's students will be expected to use proficiently for numerous engineering purposes. Taking full advantage of the features available in modern CAD programs requires that models are created in a manner that allows others to easily understand how they are organized and alter them in an…

  9. Computer-aided diagnosis for classification of focal liver lesions on contrast-enhanced ultrasonography: feature extraction and characterization of vascularity patterns

    NASA Astrophysics Data System (ADS)

    Shiraishi, Junji; Sugimoto, Katsutoshi; Kamiyama, Naohisa; Moriyasu, Fuminori; Doi, Kunio

    2008-03-01

    We have developed a computer-aided diagnostic (CAD) scheme for classifying focal liver lesions (FLLs) into hepatocellular carcinoma (HCC), liver metastasis, and hemangioma, by use of B-mode and micro flow imaging (MFI) of contrast-enhanced ultrasonography. We used 98 cases in this study, in which 104 FLLs consisted of 68 HCCs, 21 metastases, and 15 hemangiomas. MFI was obtained with contrast-enhanced low-mechanical-index (MI) pulse subtraction imaging at a fixed plane which included a distinctive cross section of the FLL. In the MFI, the inflow high signals in the plane, which were due to the vascular patterns and the contrast agent, were accumulated following flash scanning with a high-MI ultrasound exposure. In this study, in addition to the existing 29 image features extracted from MFI images, such as replenishment time, the average and the standard deviation of pixel values in a FLL, and the average thickness of vessel-like patterns, four types of image features were extracted from MFI, temporal subtraction and B-mode images based on small square regions of interest (ROIs: 4x4 matrix size) placed to cover a whole region of the FLL. The four features were 1) uniformity of average pixel values for all ROIs, 2) peak pixel values in a histogram of average pixel values of ROIs, 3) fraction of hypoechoic regions within an FLL, and 4) cross-correlation of pixel values within an FLL between B-mode and MFI images. Overall classification accuracies performed by this CAD scheme were 87.5% for all 104 liver lesions.

  10. A structural-functional MRI-based disease atlas: application to computer-aided-diagnosis of prostate cancer

    NASA Astrophysics Data System (ADS)

    Xiao, G.; Bloch, B.; Chappelow, J.; Genega, E.; Rofsky, N.; Lenkinski, R.; Madabhushi, A.

    2010-03-01

    Different imaging modalities or protocols of a single patient may convey different types of information regarding a disease for the same anatomical organ/tissue. On the other hand, multi-modal/multi-protocol medical images from several different patients can also provide spatial statistics of the disease occurrence, which in turn can greatly aid in disease diagnosis and aid in improved, accurate biopsy and targeted treatment. It is therefore important to not only integrate medical images from multiple patients into a common coordinate frame (in the form of a population-based atlas), but also find the correlation between these multi-modal/multi-protocol data features and the disease spatial distribution in order to identify different quantitative structural and functional disease signatures. Most previous work on construction of anatomical atlases has focused on deriving a population-based atlas for the purpose of deriving the spatial statistics. Moreover, these models are typically derived from normal or healthy subjects, either explicitly or implicitly, where it is assumed that the inter-patient pathological variation is not large. These methods are not suitable for constructing a disease atlas, where significant differences between patients on account of disease related variations can be expected. In this paper, we present a novel framework for the construction of a multi-parametric MRI-based data-driven disease atlas consisting of multi-modal and multi-protocol data from across multiple patient studies. Our disease atlas contains 3 Tesla structural (T2) and functional (dynamic contrast enhanced (DCE)) prostate in vivo MRI with corresponding whole mount histology specimens obtained via radical prostatectomy. Our atlas construction framework comprises 3 distinct modules: (a) determination of disease spatial extent on the multi-protocol MR imagery for each patient, (b) construction of a multi-protocol MR imaging spatial atlas which captures the geographical

  11. Training a CAD classifier with correlated data

    NASA Astrophysics Data System (ADS)

    Dundar, Murat; Krishnapuram, Balaji; Wolf, Matthias; Lakare, Sarang; Bogoni, Luca; Bi, Jinbo; Rao, R. Bharat

    2007-03-01

    Most methods for classifier design assume that the training samples are drawn independently and identically from an unknown data generating distribution (i.i.d.), although this assumption is violated in several real life problems. Relaxing this i.i.d. assumption, we develop training algorithms for the more realistic situation where batches or sub-groups of training samples may have internal correlations, although the samples from different batches may be considered to be uncorrelated; we also consider the extension to cases with hierarchical--i.e. higher order--correlation structure between batches of training samples. After describing efficient algorithms that scale well to large datasets, we provide some theoretical analysis to establish their validity. Experimental results from real-life Computer Aided Detection (CAD) problems indicate that relaxing the i.i.d. assumption leads to statistically significant improvements in the accuracy of the learned classifier.

  12. Understanding dental CAD/CAM for restorations--the digital workflow from a mechanical engineering viewpoint.

    PubMed

    Tapie, L; Lebon, N; Mawussi, B; Fron Chabouis, H; Duret, F; Attal, J-P

    2015-01-01

    As digital technology infiltrates every area of daily life, including the field of medicine, so it is increasingly being introduced into dental practice. Apart from chairside practice, computer-aided design/computer-aided manufacturing (CAD/CAM) solutions are available for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental solutions can be considered a chain of digital devices and software for the almost automatic design and creation of dental restorations. However, dentists who want to use the technology often do not have the time or knowledge to understand it. A basic knowledge of the CAD/CAM digital workflow for dental restorations can help dentists to grasp the technology and purchase a CAM/CAM system that meets the needs of their office. This article provides a computer-science and mechanical-engineering approach to the CAD/CAM digital workflow to help dentists understand the technology.

  13. Understanding dental CAD/CAM for restorations--the digital workflow from a mechanical engineering viewpoint.

    PubMed

    Tapie, L; Lebon, N; Mawussi, B; Fron Chabouis, H; Duret, F; Attal, J-P

    2015-01-01

    As digital technology infiltrates every area of daily life, including the field of medicine, so it is increasingly being introduced into dental practice. Apart from chairside practice, computer-aided design/computer-aided manufacturing (CAD/CAM) solutions are available for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental solutions can be considered a chain of digital devices and software for the almost automatic design and creation of dental restorations. However, dentists who want to use the technology often do not have the time or knowledge to understand it. A basic knowledge of the CAD/CAM digital workflow for dental restorations can help dentists to grasp the technology and purchase a CAM/CAM system that meets the needs of their office. This article provides a computer-science and mechanical-engineering approach to the CAD/CAM digital workflow to help dentists understand the technology. PMID:25911827

  14. Dental students' preferences and performance in crown design: conventional wax-added versus CAD.

    PubMed

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A

    2014-12-01

    The purpose of this study was to evaluate dental students' perceptions of traditional waxing vs. computer-aided crown design and to determine the effectiveness of either technique through comparative grading of the final products. On one of twoidentical tooth preparations, second-year students at one dental school fabricated a wax pattern for a full contour crown; on the second tooth preparation, the same students designed and fabricated an all-ceramic crown using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Projects were graded for occlusion and anatomic form by three faculty members. On completion of the projects, 100 percent of the students (n=50) completed an eight-question, five-point Likert scalesurvey, designed to assess their perceptions of and learning associated with the two design techniques. The average grades for the crown design projects were 78.3 (CAD) and 79.1 (wax design). The mean numbers of occlusal contacts were 3.8 (CAD) and 2.9(wax design), which was significantly higher for CAD (p=0.02). The survey results indicated that students enjoyed designing afull contour crown using CAD as compared to using conventional wax techniques and spent less time designing the crown using CAD. From a learning perspective, students felt that they learned more about position and the size/strength of occlusal contacts using CAD. However, students recognized that CAD technology has limits in terms of representing anatomic contours and excursive occlusion compared to conventional wax techniques. The results suggest that crown design using CAD could be considered as an adjunct to conventional wax-added techniques in preclinical fixed prosthodontic curricula.

  15. Evaluation of a computer-aided skin cancer diagnosis system for conventional digital photography with manual segmentation

    NASA Astrophysics Data System (ADS)

    Huang, Adam; Chang, Wen-Yu; Hsieh, Cheng-Han; Liu, Hsin-Yi; Chen, Gwo-Shing

    2014-03-01

    We evaluate a computer-aided diagnosis (CADx) system developed for both melanocytic and non-melanocytic skin lesions by using conventional digital photographs with lesion boundaries manually marked by a dermatologist. Clinical images of skin lesions taken by conventional digital cameras can capture useful information such as shape, color, and texture for diagnosing skin cancer. However, shape/border features are difficult to analyze automatically because skin surface reflections may change skin color and make segmentation a challenging task. In this study, two non-medical users manually mark the boundaries of a dataset of 769 (174 malignant, 595 benign) conventional photographs of melanocytic and non-melanocytic skin lesions. A state-of-the-art software system for segmenting color images, JSEG, is also tested on the same dataset. Their results are compared to a dermatologist's markings, which are used as the gold standard in this study. The human users' markings are relatively close to the gold standard and achieve an overlapping rate of 70.4% (+/- 15.3%, std) and 74.5% (+/- 14.7%, std). Compared to human users, JSEG only succeeds in segmenting 636 (82.7%) out of 769 lesions and achieves an overlapping rate of 72.4% (+/-20.4%) for these 636 lesions. The estimated area under the receiver operating characteristic curve (AUC) of the CADx by using lesion boundary markings of users 1, 2, and JSEG are 0.915, 0.940, and 0.857 respectively. Our preliminary results indicate that manual segmentation can be repeated relatively consistent compared to automatic segmentation.

  16. A Suggested Computer Aided Drafting Curriculum (Dacum Based).

    ERIC Educational Resources Information Center

    Pedras, Melvin J.; Hoggard, David

    Computer-aided drawing can bring new technology into the drafting classroom. One approach to computer-aided drafting (CAD) involves use of a personal computer and purchased software. Existing school computers could be shared to reduce costs. Following this narrative introduction, a suggested curriculum for the teaching of CAD is presented in…

  17. On the Use of CAD-Native Predicates and Geometry in Surface Meshing

    NASA Technical Reports Server (NTRS)

    Aftosmis, M. J.

    1999-01-01

    Several paradigms for accessing computer-aided design (CAD) geometry during surface meshing for computational fluid dynamics are discussed. File translation, inconsistent geometry engines, and nonnative point construction are all identified as sources of nonrobustness. The paper argues in favor of accessing CAD parts and assemblies in their native format, without translation, and for the use of CAD-native predicates and constructors in surface mesh generation. The discussion also emphasizes the importance of examining the computational requirements for exact evaluation of triangulation predicates during surface meshing.

  18. Project Integration Architecture (PIA) and Computational Analysis Programming Interface (CAPRI) for Accessing Geometry Data from CAD Files

    NASA Technical Reports Server (NTRS)

    Benyo, Theresa L.

    2002-01-01

    Integration of a supersonic inlet simulation with a computer aided design (CAD) system is demonstrated. The integration is performed using the Project Integration Architecture (PIA). PIA provides a common environment for wrapping many types of applications. Accessing geometry data from CAD files is accomplished by incorporating appropriate function calls from the Computational Analysis Programming Interface (CAPRI). CAPRI is a CAD vendor neutral programming interface that aids in acquiring geometry data directly from CAD files. The benefits of wrapping a supersonic inlet simulation into PIA using CAPRI are; direct access of geometry data, accurate capture of geometry data, automatic conversion of data units, CAD vendor neutral operation, and on-line interactive history capture. This paper describes the PIA and the CAPRI wrapper and details the supersonic inlet simulation demonstration.

  19. Fabrication of lithium silicate ceramic veneers with a CAD/CAM approach: a clinical report of cleidocranial dysplasia.

    PubMed

    da Cunha, Leonardo Fernandes; Mukai, Eduardo; Hamerschmitt, Raphael Meneghetti; Correr, Gisele Maria

    2015-05-01

    The fabrication of minimally invasive ceramic veneers remains a challenge for dental restorations involving computer-aided design and computer-aided manufacturing (CAD/CAM). The application of an appropriate CAD/CAM protocol and correlation mode not only simplifies the fabrication of ceramic veneers but also improves the resulting esthetics. Ceramic veneers can restore tooth abnormalities caused by disorders such as cleidocranial dysplasia, enamel hypoplasia, or supernumerary teeth. This report illustrates the fabrication of dental veneers with a new lithium silicate ceramic and the CAD/CAM technique in a patient with cleidocranial dysplasia.

  20. CAD systems simplify engineering drawings

    SciTech Connect

    Holt, J.

    1986-10-01

    Computer assisted drafting systems, with today's technology, provide high-quality, timely drawings that can be justified by the lower costs for the final product. The author describes Exxon Pipeline Co.'s experience in deciding on hardware and software for a CAD system installation and the benefits effected by this procedure and equipment.

  1. Design of a high-sensitivity classifier based on a genetic algorithm: application to computer-aided diagnosis

    NASA Astrophysics Data System (ADS)

    Sahiner, Berkman; Chan, Heang-Ping; Petrick, Nicholas; Helvie, Mark A.; Goodsitt, Mitchell M.

    1998-10-01

    -9155/43/10/014/img3.gif" ALIGN="MIDDLE"/>, although the latter provided a higher total area under the ROC curve. By setting an appropriate decision threshold, the high-sensitivity classifier and correctly identified 61% and 34% of the benign masses respectively without missing any malignant masses. Our results show that the choice of the feature selection technique is important in computer-aided diagnosis, and that the GA may be a useful tool for designing classifiers for lesion characterization.

  2. CAD Skills Increased through Multicultural Design Project

    ERIC Educational Resources Information Center

    Clemons, Stephanie

    2006-01-01

    This article discusses how students in a college-entry-level CAD course researched four generations of their family histories and documented cultural and symbolic influences within their family backgrounds. AutoCAD software was then used to manipulate those cultural and symbolic images to create the design for a multicultural area rug. AutoCAD was…

  3. Cool-and Unusual-CAD Applications

    ERIC Educational Resources Information Center

    Calhoun, Ken

    2004-01-01

    This article describes several very useful applications of AutoCAD that may lie outside the normal scope of application. AutoCAD commands used in this article are based on AutoCAD 2000I. The author and his students used a Hewlett Packard 750C DesignJet plotter for plotting. (Contains 5 figures and 5 photos.)

  4. A technique to improve the esthetic aspects of CAD/CAM composite resin restorations.

    PubMed

    Rocca, Giovanni Tommaso; Bonnafous, François; Rizcalla, Nicolas; Krejci, Ivo

    2010-10-01

    Bonded indirect computer-aided design/computer-aided manufacturing (CAD/CAM) restorations are increasingly gaining popularity for the restoration of large defects in posterior teeth. In addition to ceramic blocks, composite resin blocks have been developed. Composite resins blocks may have improved mechanical properties, but have poor esthetics. Thus, an esthetic modification of the restoration after machine milling may be necessary. A step-by-step procedure for the external esthetic layering of a composite CAD/CAM restoration is described. This technique can be used to repair or modify any composite resin restoration.

  5. Understanding dental CAD/CAM for restorations--accuracy from a mechanical engineering viewpoint.

    PubMed

    Tapie, Laurent; Lebon, Nicolas; Mawussi, Bernardin; Fron-Chabouis, Hélène; Duret, Francois; Attal, Jean-Pierre

    2015-01-01

    As is the case in the field of medicine, as well as in most areas of daily life, digital technology is increasingly being introduced into dental practice. Computer-aided design/ computer-aided manufacturing (CAD/CAM) solutions are available not only for chairside practice but also for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental practice can be considered as the handling of devices and software processing for the almost automatic design and creation of dental restorations. However, dentists who want to use dental CAD/CAM systems often do not have enough information to understand the variations offered by such technology practice. Knowledge of the random and systematic errors in accuracy with CAD/CAM systems can help to achieve successful restorations with this technology, and help with the purchasing of a CAD/CAM system that meets the clinical needs of restoration. This article provides a mechanical engineering viewpoint of the accuracy of CAD/ CAM systems, to help dentists understand the impact of this technology on restoration accuracy. PMID:26734668

  6. Rationale for the Use of CAD/CAM Technology in Implant Prosthodontics

    PubMed Central

    Abduo, Jaafar; Lyons, Karl

    2013-01-01

    Despite the predictable longevity of implant prosthesis, there is an ongoing interest to continue to improve implant prosthodontic treatment and outcomes. One of the developments is the application of computer-aided design and computer-aided manufacturing (CAD/CAM) to produce implant abutments and frameworks from metal or ceramic materials. The aim of this narrative review is to critically evaluate the rationale of CAD/CAM utilization for implant prosthodontics. To date, CAD/CAM allows simplified production of precise and durable implant components. The precision of fit has been proven in several laboratory experiments and has been attributed to the design of implants. Milling also facilitates component fabrication from durable and aesthetic materials. With further development, it is expected that the CAD/CAM protocol will be further simplified. Although compelling clinical evidence supporting the superiority of CAD/CAM implant restorations is still lacking, it is envisioned that CAD/CAM may become the main stream for implant component fabrication. PMID:23690778

  7. Understanding dental CAD/CAM for restorations--accuracy from a mechanical engineering viewpoint.

    PubMed

    Tapie, Laurent; Lebon, Nicolas; Mawussi, Bernardin; Fron-Chabouis, Hélène; Duret, Francois; Attal, Jean-Pierre

    2015-01-01

    As is the case in the field of medicine, as well as in most areas of daily life, digital technology is increasingly being introduced into dental practice. Computer-aided design/ computer-aided manufacturing (CAD/CAM) solutions are available not only for chairside practice but also for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental practice can be considered as the handling of devices and software processing for the almost automatic design and creation of dental restorations. However, dentists who want to use dental CAD/CAM systems often do not have enough information to understand the variations offered by such technology practice. Knowledge of the random and systematic errors in accuracy with CAD/CAM systems can help to achieve successful restorations with this technology, and help with the purchasing of a CAD/CAM system that meets the clinical needs of restoration. This article provides a mechanical engineering viewpoint of the accuracy of CAD/ CAM systems, to help dentists understand the impact of this technology on restoration accuracy.

  8. Integration of a CAD System Into an MDO Framework

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.; Samareh, J. A.; Weston, R. P.; Zorumski, W. E.

    1998-01-01

    NASA Langley has developed a heterogeneous distributed computing environment, called the Framework for Inter-disciplinary Design Optimization, or FIDO. Its purpose has been to demonstrate framework technical feasibility and usefulness for optimizing the preliminary design of complex systems and to provide a working environment for testing optimization schemes. Its initial implementation has been for a simplified model of preliminary design of a high-speed civil transport. Upgrades being considered for the FIDO system include a more complete geometry description, required by high-fidelity aerodynamics and structures codes and based on a commercial Computer Aided Design (CAD) system. This report presents the philosophy behind some of the decisions that have shaped the FIDO system and gives a brief case study of the problems and successes encountered in integrating a CAD system into the FEDO framework.

  9. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  10. Tooth-colored CAD/CAM monolithic restorations.

    PubMed

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials.

  11. CAD system for the assistance of a comparative reading for lung cancer using retrospective helical CT images

    NASA Astrophysics Data System (ADS)

    Kubo, Mitsuru; Yamamoto, Takuya; Kawata, Yoshiki; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Kaneko, Masahiro; Kusumoto, Masahiko; Moriyama, Noriyuki; Mori, Kiyoshi; Nishiyama, Hiroyuki

    2001-07-01

    The objective of our study is to develop a new computer- aided diagnosis (CAD) system to support effectually the comparative reading using serial helical CT images for lung cancer screening without using the film display. The placement of pulmonary shadows between the serial helical CT images is sometimes different to change the size and the shape of lung by inspired air. We analyzed the motion of the pulmonary structure using the serial cases of 17 pairs, which are different in the inspired air. This algorithm consists of the extraction process of region of interest such as the lung, heart and blood vessels region using thresholding and fuzzy c-means method, and the comparison process of each region in serial CT images using template matching. We validated the efficiency of this algorithm by application to image of 60 subjects. The algorithm could compare the slice images correctly in most combinations with respect to physician's point of view. The experimental results of the proposed algorithm indicate that our CAD system without using the film display is useful to increase the efficiency of the mass screening process.

  12. A prostate CAD system based on multiparametric analysis of DCE T1-w, and DW automatically registered images

    NASA Astrophysics Data System (ADS)

    Giannini, Valentina; Vignati, Anna; Mazzetti, Simone; De Luca, Massimo; Bracco, Christian; Stasi, Michele; Russo, Filippo; Armando, Enrico; Regge, Daniele

    2013-02-01

    Prostate specific antigen (PSA)-based screening reduces the rate of death from prostate cancer (PCa) by 31%, but this benefit is associated with a high risk of overdiagnosis and overtreatment. As prostate transrectal ultrasound-guided biopsy, the standard procedure for prostate histological sampling, has a sensitivity of 77% with a considerable false-negative rate, more accurate methods need to be found to detect or rule out significant disease. Prostate magnetic resonance imaging has the potential to improve the specificity of PSA-based screening scenarios as a non-invasive detection tool, in particular exploiting the combination of anatomical and functional information in a multiparametric framework. The purpose of this study was to describe a computer aided diagnosis (CAD) method that automatically produces a malignancy likelihood map by combining information from dynamic contrast enhanced MR images and diffusion weighted images. The CAD system consists of multiple sequential stages, from a preliminary registration of images of different sequences, in order to correct for susceptibility deformation and/or movement artifacts, to a Bayesian classifier, which fused all the extracted features into a probability map. The promising results (AUROC=0.87) should be validated on a larger dataset, but they suggest that the discrimination on a voxel basis between benign and malignant tissues is feasible with good performances. This method can be of benefit to improve the diagnostic accuracy of the radiologist, reduce reader variability and speed up the reading time, automatically highlighting probably cancer suspicious regions.

  13. Computer-aided assessment of diagnostic images for epidemiological research

    PubMed Central

    2009-01-01

    Background Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD) algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research. Methods Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and severity of lesions. Available image processing and statistical methods that were easily implementable were used as the basis for the CAD algorithm. The performance of the system was compared to the subjective assessment of five reviewers using 60 simulated images. Cortical cataract severity scores from 0 to 16 were assigned to the images by the reviewers and the CAD system, with each image assessed twice to obtain a measure of variability. Image characteristics that affected reviewer bias were also assessed by systematically varying the appearance of the simulated images. Results The algorithm yielded severity scores with smaller bias on images where cataract severity was mild to moderate (approximately ≤ 6/16ths). On high severity images, the bias of the CAD system exceeded that of the reviewers. The variability of the CAD system was zero on repeated images but ranged from 0.48 to 1.22 for the reviewers. The direction and magnitude of the bias exhibited by the reviewers was a function of the number of cataract opacities, the shape and the contrast of the lesions in the simulated images. Conclusion CAD systems are feasible to implement with available software and can be valuable when medical images contain exposure or outcome information for etiologic research. Our

  14. Computer-aided detection of mammographic masses based on content-based image retrieval

    NASA Astrophysics Data System (ADS)

    Jin, Renchao; Meng, Bo; Song, Enmin; Xu, Xiangyang; Jiang, Luan

    2007-03-01

    A method for computer-aided detection (CAD) of mammographic masses is proposed and a prototype CAD system is presented. The method is based on content-based image retrieval (CBIR). A mammogram database containing 2000 mammographic regions is built in our prototype CBIR-CAD system. Every region of interested (ROI) in the database has known pathology. Specifically, there are 583 ROIs depicting biopsy-proven masses, and the rest 1417 ROIs are normal. Whenever a suspicious ROI is detected in a mammogram by a radiologist, it can be submitted as a query to this CBIRCAD system. As the query results, a series of similar ROI images together with their known pathology knowledge will be retrieved from the database and displayed in the screen in descending order of their similarities to the query ROI to help the radiologist to make the diagnosis decision. Furthermore, our CBIR-CAD system will output a decision index (DI) to quantitatively indicate the probability that the query ROI contains a mass. The DI is calculated by the query matches. In the querying process, 24 features are extracted from each ROI to form a 24-dimensional vector. Euclidean distance in the 24-dimensional feature vector space is applied to measure the similarities between ROIs. The prototype CBIR-CAD system is evaluated based on the leave-one-out sampling scheme. The experiment results showed that the system can achieve a receiver operating characteristic (ROC) area index A Z =0.84 for detection of mammographic masses, which is better than the best results achieved by the other known mass CAD systems.

  15. CAD/CAM at a Distance: Assessing the Effectiveness of Web-Based Instruction To Meet Workforce Development Needs. AIR 2000 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Wilkerson, Joyce A.; Elkins, Susan A.

    This qualitative case study assessed web-based instruction in a computer-aided design/computer-assisted manufacturing (CAD/CAM) course designed for workforce development. The study examined students' and instructors' experience in a CAD/CAM course delivered exclusively on the Internet, evaluating course content and delivery, clarity of…

  16. A two-view ultrasound CAD system for spina bifida detection using Zernike features

    NASA Astrophysics Data System (ADS)

    Konur, Umut; Gürgen, Fikret; Varol, Füsun

    2011-03-01

    In this work, we address a very specific CAD (Computer Aided Detection/Diagnosis) problem and try to detect one of the relatively common birth defects - spina bifida, in the prenatal period. To do this, fetal ultrasound images are used as the input imaging modality, which is the most convenient so far. Our approach is to decide using two particular types of views of the fetal neural tube. Transcerebellar head (i.e. brain) and transverse (axial) spine images are processed to extract features which are then used to classify healthy (normal), suspicious (probably defective) and non-decidable cases. Decisions raised by two independent classifiers may be individually treated, or if desired and data related to both modalities are available, those decisions can be combined to keep matters more secure. Even more security can be attained by using more than two modalities and base the final decision on all those potential classifiers. Our current system relies on feature extraction from images for cases (for particular patients). The first step is image preprocessing and segmentation to get rid of useless image pixels and represent the input in a more compact domain, which is hopefully more representative for good classification performance. Next, a particular type of feature extraction, which uses Zernike moments computed on either B/W or gray-scale image segments, is performed. The aim here is to obtain values for indicative markers that signal the presence of spina bifida. Markers differ depending on the image modality being used. Either shape or texture information captured by moments may propose useful features. Finally, SVM is used to train classifiers to be used as decision makers. Our experimental results show that a promising CAD system can be actualized for the specific purpose. On the other hand, the performance of such a system would highly depend on the qualities of image preprocessing, segmentation, feature extraction and comprehensiveness of image data.

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:26346558

  19. Computer-aided detection of prostate cancer in T2-weighted MRI within the peripheral zone.

    PubMed

    Rampun, Andrik; Zheng, Ling; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-07-01

    In this paper we propose a prostate cancer computer-aided diagnosis (CAD) system and suggest a set of discriminant texture descriptors extracted from T2-weighted MRI data which can be used as a good basis for a multimodality system. For this purpose, 215 texture descriptors were extracted and eleven different classifiers were employed to achieve the best possible results. The proposed method was tested based on 418 T2-weighted MR images taken from 45 patients and evaluated using 9-fold cross validation with five patients in each fold. The results demonstrated comparable results to existing CAD systems using multimodality MRI. We achieved an area under the receiver operating curve (A z ) values equal to [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] for Bayesian networks, ADTree, random forest and multilayer perceptron classifiers, respectively, while a meta-voting classifier using average probability as a combination rule achieved [Formula: see text]. PMID:27272935

  20. Contrast enhancement in dense breast images to aid clustered microcalcifications detection.

    PubMed

    Nunes, Fátima L S; Schiabel, Homero; Goes, Claudio E

    2007-03-01

    This paper presents a method to provide contrast enhancement in dense breast digitized images, which are difficult cases in testing of computer-aided diagnosis (CAD) schemes. Three techniques were developed, and data from each method were combined to provide a better result in relation to detection of clustered microcalcifications. Results obtained during the tests indicated that, by combining all the developed techniques, it is possible to improve the performance of a processing scheme designed to detect microcalcification clusters. It also allows operators to distinguish some of these structures in low-contrast images, which were not detected via conventional processing before the contrast enhancement. This investigation shows the possibility of improving CAD schemes for better detection of microcalcifications in dense breast images.

  1. Computer-aided detection of prostate cancer in T2-weighted MRI within the peripheral zone.

    PubMed

    Rampun, Andrik; Zheng, Ling; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-07-01

    In this paper we propose a prostate cancer computer-aided diagnosis (CAD) system and suggest a set of discriminant texture descriptors extracted from T2-weighted MRI data which can be used as a good basis for a multimodality system. For this purpose, 215 texture descriptors were extracted and eleven different classifiers were employed to achieve the best possible results. The proposed method was tested based on 418 T2-weighted MR images taken from 45 patients and evaluated using 9-fold cross validation with five patients in each fold. The results demonstrated comparable results to existing CAD systems using multimodality MRI. We achieved an area under the receiver operating curve (A z ) values equal to [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] for Bayesian networks, ADTree, random forest and multilayer perceptron classifiers, respectively, while a meta-voting classifier using average probability as a combination rule achieved [Formula: see text].

  2. Computer-Aided Assessment of Tumor Grade for Breast Cancer in Ultrasound Images

    PubMed Central

    2015-01-01

    This study involved developing a computer-aided diagnosis (CAD) system for discriminating the grades of breast cancer tumors in ultrasound (US) images. Histological tumor grades of breast cancer lesions are standard prognostic indicators. Tumor grade information enables physicians to determine appropriate treatments for their patients. US imaging is a noninvasive approach to breast cancer examination. In this study, 148 3-dimensional US images of malignant breast tumors were obtained. Textural, morphological, ellipsoid fitting, and posterior acoustic features were quantified to characterize the tumor masses. A support vector machine was developed to classify breast tumor grades as either low or high. The proposed CAD system achieved an accuracy of 85.14% (126/148), a sensitivity of 79.31% (23/29), a specificity of 86.55% (103/119), and an AZ of 0.7940. PMID:25810750

  3. Computer-aided assessment of tumor grade for breast cancer in ultrasound images.

    PubMed

    Chen, Dar-Ren; Chien, Cheng-Liang; Kuo, Yan-Fu

    2015-01-01

    This study involved developing a computer-aided diagnosis (CAD) system for discriminating the grades of breast cancer tumors in ultrasound (US) images. Histological tumor grades of breast cancer lesions are standard prognostic indicators. Tumor grade information enables physicians to determine appropriate treatments for their patients. US imaging is a noninvasive approach to breast cancer examination. In this study, 148 3-dimensional US images of malignant breast tumors were obtained. Textural, morphological, ellipsoid fitting, and posterior acoustic features were quantified to characterize the tumor masses. A support vector machine was developed to classify breast tumor grades as either low or high. The proposed CAD system achieved an accuracy of 85.14% (126/148), a sensitivity of 79.31% (23/29), a specificity of 86.55% (103/119), and an A Z of 0.7940.

  4. Quantitative Analysis Of Lung Texture For Computer-Aided Diagnosis Of Interstitial Disease In Digital Chest Radiographs

    NASA Astrophysics Data System (ADS)

    Katsuragawa, Shigehiko; Doi, Kunio; MacMahon, Heber

    1988-06-01

    We have employed physical measures of lung texture in an automated method of detecting and characterizing interstitial lung disease in digital chest radiographs. In addition, by using an analysis of these measures relative to an accumulated data base, we have devised an automated classification method for distinguishing between normal lungs and abnormal lungs with interstitial disease. Our results suggest that this computerized method can be a valuable aid to radiologists in their assessment of interstitial lung infiltrates.

  5. Getting into CAD at the Savannah River Plant

    SciTech Connect

    Scoggins, W.R.

    1984-01-01

    In 1978, the Savannah River Plant (SRP) Project Department was producing approximately 1100 new drawings and 3000 revisions per year, with a force of 30 draftsmen. Design services for the Plant were increasing due to changing programs, obsolescent equipment replacements and added security requirements. This increasing workload greatly increased the engineering drafting backlog. At the same time, many draftsmen were approaching retirement age and were to be replaced with unskilled draftsman trainees. A proposal was presented to management to acquire a Computer Aided Drafting (CAD) system to produce instrument and electrical drawings which comprised 30% of the work load.

  6. Extending Engineering Design Graphics Laboratories to Have a CAD/CAM Component: Implementation Issues.

    ERIC Educational Resources Information Center

    Juricic, Davor; Barr, Ronald E.

    1996-01-01

    Reports on a project that extended the Engineering Design Graphics curriculum to include instruction and laboratory experience in computer-aided design, analysis, and manufacturing (CAD/CAM). Discusses issues in project implementation, including introduction of finite element analysis to lower-division students, feasibility of classroom prototype…

  7. Using Claris CAD To Develop a Floor Plan. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Pawlowicz, Bruce; Johnson, Tom

    This learning module for a high school architectural drafting course introduces students to the use of Claris CAD (Computer Aided Drafting) to develop a floor plan. The six sections of the module are the following: module objectives, content outline, teaching methods, student activities, resource list, and evaluation (pretest, posttest). Student…

  8. Preparing for High Technology: CAD/CAM Programs. Research & Development Series No. 234.

    ERIC Educational Resources Information Center

    Abram, Robert; And Others

    This guide is one of three developed to provide information and resources to assist in planning and developing postsecondary technican training programs in high technology areas. It is specifically intended for vocational-technical educators and planners in the initial stages of planning a specialized training option in computer-aided design (CAD)…

  9. Classroom Experiences in an Engineering Design Graphics Course with a CAD/CAM Extension.

    ERIC Educational Resources Information Center

    Barr, Ronald E.; Juricic, Davor

    1997-01-01

    Reports on the development of a new CAD/CAM laboratory experience for an Engineering Design Graphics (EDG) course. The EDG curriculum included freehand sketching, introduction to Computer-Aided Design and Drafting (CADD), and emphasized 3-D solid modeling. Reviews the project and reports on the testing of the new laboratory components which were…

  10. Use of MathCAD in a Pharmacokinetics Course for PharmD Students.

    ERIC Educational Resources Information Center

    Sullivan, Timothy J.

    1992-01-01

    This paper describes the application of the Student Edition of MathCAD as a computational aid in an introductory graduate level pharmacokinetics course. The program allows the student to perform mathematical calculations and analysis on a computer screen. The advantages and disadvantages of this application are discussed. (GLR)

  11. An online real-time DICOM web-based computer-aided diagnosis system for bone age assessment of children in a PACS environment

    NASA Astrophysics Data System (ADS)

    Ma, Kevin C.; Zhang, Aifeng; Moin, Paymann; Fleshman, Mariam; Vachon, Linda; Liu, Brent; Huang, H. K.

    2009-02-01

    Bone age assessment is a radiological procedure to evaluate a child's bone age based on his or her left-hand x-ray image. The current standard is to match patient's hand with Greulich & Pyle hand atlas, which is outdated by 50 years and only uses subjects from one region and one ethnicity. To improve bone age assessment accuracy for today's children, an automated race- and gender-specific bone age assessment (BAA) system has been developed in IPILab. 1390 normal left-hand x-ray images have been collected at Children's Hospital of Los Angeles (CHLA) to form the digital hand atlas (DHA). DHA includes both male and female children of ages one to eighteen and of four ethnic groups: African American, Asian American, Caucasian, and Hispanic. In order to apply DHA and BAA CAD into a clinical environment, a web-based BAA CAD system and graphical user interface (GUI) has been implemented in Women and Children's Hospital at Los Angeles County (WCH-LAC). A CAD server has been integrated in WCH's PACS environment, and a clinical validation workflow has been designed for radiologists, who compare CAD readings with G&P readings and determine which reading is more suited for a certain case. Readings are logged in database and analyzed to assess BAA CAD performance in a clinical setting. The result is a successful installation of web-based BAA CAD system in a clinical setting.

  12. A CAD system based on spherical dual representations

    SciTech Connect

    Roach, J.W.; Paripati, P.K.; Wright, J.S.

    1987-08-01

    Computer-aided design (CAD) systems typically have many different functions: drafting, two-dimensional modeling, three-dimensional modeling, finite element analysis, and fit and tolerancing of parts. The authors report on the construction of a CAD system based on shape representation ideas used in the vision community to determine the shape of an object from its image. In the long term, they propose to construct a combined CAD and sensing system based on the same underlying object models. Considerable advantages follow from building a model-driven sensor fusion system that uses a common geometric model. In a manufacturing environment, for example, a library of objects can be built up and its models used in a vision and touch sensing system integrated into an automated assembly line to discriminate between objects and determine orientation and distance. If such a system could be made robust and highly reliable, then some of the most difficult problems that plague attempts to create a fully flexible automated environment would be solved.

  13. Complete-mouth rehabilitation using a 3D printing technique and the CAD/CAM double scanning method: A clinical report.

    PubMed

    Joo, Han-Sung; Park, Sang-Won; Yun, Kwi-Dug; Lim, Hyun-Pil

    2016-07-01

    According to evolving computer-aided design/computer-aided manufacturing (CAD/CAM) technology, ceramic materials such as zirconia can be used to create fixed dental prostheses for partial removable dental prostheses. Since 3D printing technology was introduced a few years ago, dental applications of this technique have gradually increased. This clinical report presents a complete-mouth rehabilitation using 3D printing and the CAD/CAM double-scanning method.

  14. Complete-mouth rehabilitation using a 3D printing technique and the CAD/CAM double scanning method: A clinical report.

    PubMed

    Joo, Han-Sung; Park, Sang-Won; Yun, Kwi-Dug; Lim, Hyun-Pil

    2016-07-01

    According to evolving computer-aided design/computer-aided manufacturing (CAD/CAM) technology, ceramic materials such as zirconia can be used to create fixed dental prostheses for partial removable dental prostheses. Since 3D printing technology was introduced a few years ago, dental applications of this technique have gradually increased. This clinical report presents a complete-mouth rehabilitation using 3D printing and the CAD/CAM double-scanning method. PMID:26946918

  15. Computer-Aided Drafting. Education for Technology Employment.

    ERIC Educational Resources Information Center

    Northern Illinois Univ., De Kalb. Dept. of Technology.

    This computer-aided drafting (CAD) curriculum was developed to provide drafting instructors in Illinois with a useful guide for relating an important new technological advance to the vocational classroom. The competency-based learning activity guides are written to be used with any CAD system being used at the secondary and postsecondary levels.…

  16. Exogenous ochronosis in a Chinese patient: use of dermoscopy aids early diagnosis and selection of biopsy site

    PubMed Central

    Liu, Wen Chun; Tey, Hong Liang; Lee, Joyce Siong See; Goh, Boon Kee

    2014-01-01

    The diagnosis of exogenous ochronosis is often challenging and requires a high index of suspicion. Herein, we report a case of exogenous ochronosis in a Chinese patient. The condition was caused by the use of bleaching agents, including creams containing hydroquinone. We demonstrate the use of dermoscopy as an invaluable tool for the early recognition of the condition, as well as in the selection of an appropriate site for a skin biopsy. PMID:24452981

  17. Different CAD/CAM-processing routes for zirconia restorations: influence on fitting accuracy.

    PubMed

    Kohorst, Philipp; Junghanns, Janet; Dittmer, Marc P; Borchers, Lothar; Stiesch, Meike

    2011-08-01

    The aim of the present in vitro study was to evaluate the influence of different processing routes on the fitting accuracy of four-unit zirconia fixed dental prostheses (FDPs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM). Three groups of zirconia frameworks with ten specimens each were fabricated. Frameworks of one group (CerconCAM) were produced by means of a laboratory CAM-only system. The other frameworks were made with different CAD/CAM systems; on the one hand by in-laboratory production (CerconCAD/CAM) and on the other hand by centralized production in a milling center (Compartis) after forwarding geometrical data. Frameworks were then veneered with the recommended ceramics, and marginal accuracy was determined using a replica technique. Horizontal marginal discrepancy, vertical marginal discrepancy, absolute marginal discrepancy, and marginal gap were evaluated. Statistical analyses were performed by one-way analysis of variance (ANOVA), with the level of significance chosen at 0.05. Mean horizontal discrepancies ranged between 22 μm (CerconCAM) and 58 μm (Compartis), vertical discrepancies ranged between 63 μm (CerconCAD/CAM) and 162 μm (CerconCAM), and absolute marginal discrepancies ranged between 94 μm (CerconCAD/CAM) and 181 μm (CerconCAM). The marginal gap varied between 72 μm (CerconCAD/CAM) and 112 μm (CerconCAM, Compartis). Statistical analysis revealed that, with all measurements, the marginal accuracy of the zirconia FDPs was significantly influenced by the processing route used (p < 0.05). Within the limitations of this study, all restorations showed a clinically acceptable marginal accuracy; however, the results suggest that the CAD/CAM systems are more precise than the CAM-only system for the manufacture of four-unit FDPs. PMID:20495937

  18. From Artisanal to CAD-CAM Blocks: State of the Art of Indirect Composites.

    PubMed

    Mainjot, A K; Dupont, N M; Oudkerk, J C; Dewael, T Y; Sadoun, M J

    2016-05-01

    Indirect composites have been undergoing an impressive evolution over the last few years. Specifically, recent developments in computer-aided design-computer-aided manufacturing (CAD-CAM) blocks have been associated with new polymerization modes, innovative microstructures, and different compositions. All these recent breakthroughs have introduced important gaps among the properties of the different materials. This critical state-of-the-art review analyzes the strengths and weaknesses of the different varieties of CAD-CAM composite materials, especially as compared with direct and artisanal indirect composites. Indeed, new polymerization modes used for CAD-CAM blocks-especially high temperature (HT) and, most of all, high temperature-high pressure (HT-HP)-are shown to significantly increase the degree of conversion in comparison with light-cured composites. Industrial processes also allow for the augmentation of the filler content and for the realization of more homogeneous structures with fewer flaws. In addition, due to their increased degree of conversion and their different monomer composition, some CAD-CAM blocks are more advantageous in terms of toxicity and monomer release. Finally, materials with a polymer-infiltrated ceramic network (PICN) microstructure exhibit higher flexural strength and a more favorable elasticity modulus than materials with a dispersed filler microstructure. Consequently, some high-performance composite CAD-CAM blocks-particularly experimental PICNs-can now rival glass-ceramics, such as lithium-disilicate glass-ceramics, for use as bonded partial restorations and crowns on natural teeth and implants. Being able to be manufactured in very low thicknesses, they offer the possibility of developing innovative minimally invasive treatment strategies, such as "no prep" treatment of worn dentition. Current issues are related to the study of bonding and wear properties of the different varieties of CAD-CAM composites. There is also a crucial

  19. Different CAD/CAM-processing routes for zirconia restorations: influence on fitting accuracy.

    PubMed

    Kohorst, Philipp; Junghanns, Janet; Dittmer, Marc P; Borchers, Lothar; Stiesch, Meike

    2011-08-01

    The aim of the present in vitro study was to evaluate the influence of different processing routes on the fitting accuracy of four-unit zirconia fixed dental prostheses (FDPs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM). Three groups of zirconia frameworks with ten specimens each were fabricated. Frameworks of one group (CerconCAM) were produced by means of a laboratory CAM-only system. The other frameworks were made with different CAD/CAM systems; on the one hand by in-laboratory production (CerconCAD/CAM) and on the other hand by centralized production in a milling center (Compartis) after forwarding geometrical data. Frameworks were then veneered with the recommended ceramics, and marginal accuracy was determined using a replica technique. Horizontal marginal discrepancy, vertical marginal discrepancy, absolute marginal discrepancy, and marginal gap were evaluated. Statistical analyses were performed by one-way analysis of variance (ANOVA), with the level of significance chosen at 0.05. Mean horizontal discrepancies ranged between 22 μm (CerconCAM) and 58 μm (Compartis), vertical discrepancies ranged between 63 μm (CerconCAD/CAM) and 162 μm (CerconCAM), and absolute marginal discrepancies ranged between 94 μm (CerconCAD/CAM) and 181 μm (CerconCAM). The marginal gap varied between 72 μm (CerconCAD/CAM) and 112 μm (CerconCAM, Compartis). Statistical analysis revealed that, with all measurements, the marginal accuracy of the zirconia FDPs was significantly influenced by the processing route used (p < 0.05). Within the limitations of this study, all restorations showed a clinically acceptable marginal accuracy; however, the results suggest that the CAD/CAM systems are more precise than the CAM-only system for the manufacture of four-unit FDPs.

  20. Teaching Computer-Aided Design of Fluid Flow and Heat Transfer Engineering Equipment.

    ERIC Educational Resources Information Center

    Gosman, A. D.; And Others

    1979-01-01

    Describes a teaching program for fluid mechanics and heat transfer which contains both computer aided learning (CAL) and computer aided design (CAD) components and argues that the understanding of the physical and numerical modeling taught in the CAL course is essential to the proper implementation of CAD. (Author/CMV)

  1. The Challenging Academic Development (CAD) Collective

    ERIC Educational Resources Information Center

    Peseta, Tai

    2005-01-01

    This article discusses the Challenging Academic Development (CAD) Collective and describes how it came out of a symposium called "Liminality, identity, and hybridity: On the promise of new conceptual frameworks for theorising academic/faculty development." The CAD Collective is and represents a space where people can open up their contexts and…

  2. A vector machine formulation with application to the computer-aided diagnosis of breast cancer from DCE-MRI screening examinations.

    PubMed

    Levman, Jacob E D; Warner, Ellen; Causer, Petrina; Martel, Anne L

    2014-02-01

    This study investigates the use of a proposed vector machine formulation with application to dynamic contrast-enhanced magnetic resonance imaging examinations in the context of the computer-aided diagnosis of breast cancer. This paper describes a method for generating feature measurements that characterize a lesion's vascular heterogeneity as well as a supervised learning formulation that represents an improvement over the conventional support vector machine in this application. Spatially varying signal-intensity measures were extracted from the examinations using principal components analysis and the machine learning technique known as the support vector machine (SVM) was used to classify the results. An alternative vector machine formulation was found to improve on the results produced by the established SVM in randomized bootstrap validation trials, yielding a receiver-operating characteristic curve area of 0.82 which represents a statistically significant improvement over the SVM technique in this application.

  3. The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis.

    PubMed

    Sun, Weiyi; Sun, Jian; Zou, Lili; Shen, Kaini; Zhong, Dingrong; Zhou, Daobin; Sun, Wei; Li, Jian

    2015-01-01

    Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove contaminants with a 10-kDa cutoff ultrafiltration unit and can accelerate the digestion process with the assistance of a microwave. Additionally, two parameters (P- and D-scores) based on the exponentially modified protein abundance index were developed to define the existence of amyloid deposits and those causative proteins with the greatest abundance. Using our protocol, twenty cases of systemic amyloidosis that were well-typed according to clinical diagnostic standards (training group) and another twenty-four cases without subtype diagnoses (validation group) were analyzed. Using this approach, sample preparation could be completed within four hours. We successfully subtyped 100% of the cases in the training group, and the diagnostic success rate in the validation group was 91.7%. This maFASP-aided proteomic protocol represents an efficient approach for amyloid diagnosis and subtyping, particularly for serum-contaminated samples. PMID:25984759

  4. The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis

    PubMed Central

    Zou, Lili; Shen, Kaini; Zhong, Dingrong; Zhou, Daobin; Sun, Wei; Li, Jian

    2015-01-01

    Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove contaminants with a 10-kDa cutoff ultrafiltration unit and can accelerate the digestion process with the assistance of a microwave. Additionally, two parameters (P- and D-scores) based on the exponentially modified protein abundance index were developed to define the existence of amyloid deposits and those causative proteins with the greatest abundance. Using our protocol, twenty cases of systemic amyloidosis that were well-typed according to clinical diagnostic standards (training group) and another twenty-four cases without subtype diagnoses (validation group) were analyzed. Using this approach, sample preparation could be completed within four hours. We successfully subtyped 100% of the cases in the training group, and the diagnostic success rate in the validation group was 91.7%. This maFASP-aided proteomic protocol represents an efficient approach for amyloid diagnosis and subtyping, particularly for serum-contaminated samples. PMID:25984759

  5. Increasing productivity of the McAuto CAD/CAE system by user-specific applications programming

    NASA Technical Reports Server (NTRS)

    Plotrowski, S. M.; Vu, T. H.

    1985-01-01

    Significant improvements in the productivity of the McAuto Computer-Aided Design/Computer-Aided Engineering (CAD/CAE) system were achieved by applications programming using the system's own Graphics Interactive Programming language (GRIP) and the interface capabilities with the main computer on which the system resides. The GRIP programs for creating springs, bar charts, finite element model representations and aiding management planning are presented as examples.

  6. Custom hip prostheses by integrating CAD and casting technology

    NASA Astrophysics Data System (ADS)

    Silva, Pedro F.; Leal, Nuno; Neto, Rui J.; Lino, F. Jorge; Reis, Ana

    2012-09-01

    Total Hip Arthroplasty (THA) is a surgical intervention that is being achieving high rates of success, leaving room to research on long run durability, patient comfort and costs reduction. Even so, up to the present, little research has been done to improve the method of manufacturing customized prosthesis. The common customized prostheses are made by full machining. This document presents a different approach methodology which combines the study of medical images, through CAD (Computer Aided Design) software, SLadditive manufacturing, ceramic shell manufacture, precision foundry with Titanium alloys and Computer Aided Manufacturing (CAM). The goal is to achieve the best comfort for the patient, stress distribution and the maximum lifetime of the prosthesis produced by this integrated methodology. The way to achieve this desiderate is to make custom hip prosthesis which are adapted to each patient needs and natural physiognomy. Not only the process is reliable, but also represents a cost reduction comparing to the conventional full machined custom hip prosthesis.

  7. Detection by PCR of Toxoplasma gondii in blood in the diagnosis of cerebral toxoplasmosis in patients with AIDS.

    PubMed Central

    Lamoril, J; Molina, J M; de Gouvello, A; Garin, Y J; Deybach, J C; Modaï, J; Derouin, F

    1996-01-01

    The polymerase chain reaction (PCR) for amplification of Toxoplasma gondii DNA was performed prospectively in the blood of 19 patients with AIDS and cerebral toxoplasmosis. The B1 gene and TGR1E sequence were used as targets and results were confirmed by hybridisation. Controls consisted of 24 HIV infected patients with tissue culture proven T gondii parasitaemia and 57 HIV infected patients without toxoplasmosis. PCR was positive with both targets in 20 of 24 samples (84%) from patients with parasitaemia. Three of 57 samples (5%) from patients without toxoplasmosis were PCR positive with either target, but none was positive with both targets. Only three of the 19 patients (16%) with cerebral toxoplasmosis had a positive PCR with both targets before the start of specific treatment. PCR performed in blood is of little diagnostic value in cases of cerebral toxoplasmosis but could be useful in patients with disseminated infection. Images PMID:8666697

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

    NASA Astrophysics Data System (ADS)

    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.

  9. [An experimental research on the fabrication of the fused porcelain to CAD/CAM molar crown].

    PubMed

    Dai, Ning; Zhou, Yongyao; Liao, Wenhe; Yu, Qing; An, Tao; Jiao, Yiqun

    2007-02-01

    This paper introduced the fabrication process of the fused porcelain to molar crown with CAD/CAM technology. Firstly, preparation teeth data was retrieved by the 3D-optical measuring system. Then, we have reconstructed the inner surface designed the outer surface shape with the computer aided design software. Finally, the mini high-speed NC milling machine was used to produce the fused porcelain to CAD/CAM molar crown. The result has proved that the fabrication process is reliable and efficient. The dental restoration quality is steady and precise. PMID:17333906

  10. Diagnostic performance of radiologists with and without different CAD systems for mammography

    NASA Astrophysics Data System (ADS)

    Lauria, Adele; Fantacci, Maria E.; Bottigli, Ubaldo; Delogu, Pasquale; Fauci, Francesco; Golosio, Bruno; Indovina, Pietro L.; Masala, Giovanni L.; Oliva, Piernicola; Palmiero, Rosa; Raso, Giuseppe; Stumbo, Simone; Tangaro, Sabina

    2003-05-01

    The purpose of this study is the evaluation of the variation of performance in terms of sensitivity and specificity of two radiologists with different experience in mammography, with and without the assistance of two different CAD systems. The CAD considered are SecondLookTM (CADx Medical Systems, Canada), and CALMA (Computer Assisted Library in MAmmography). The first is a commercial system, the other is the result of a research project, supported by INFN (Istituto Nazionale di Fisica Nucleare, Italy); their characteristics have already been reported in literature. To compare the results with and without these tools, a dataset composed by 70 images of patients with cancer (biopsy proven) and 120 images of healthy breasts (with a three years follow up) has been collected. All the images have been digitized and analysed by two CAD, then two radiologists with respectively 6 and 2 years of experience in mammography indipendently made their diagnosis without and with, the support of the two CAD systems. In this work sensitivity and specificity variation, the Az area under the ROC curve, are reported. The results show that the use of a CAD allows for a substantial increment in sensitivity and a less pronounced decrement in specificity. The extent of these effects depends on the experience of the readers and is comparable for the two CAD considered.

  11. Computer-Aided Diagnosis with Deep Learning Architecture: Applications to Breast Lesions in US Images and Pulmonary Nodules in CT Scans

    NASA Astrophysics Data System (ADS)

    Cheng, Jie-Zhi; Ni, Dong; Chou, Yi-Hong; Qin, Jing; Tiu, Chui-Mei; Chang, Yeun-Chung; Huang, Chiun-Sheng; Shen, Dinggang; Chen, Chung-Ming

    2016-04-01

    This paper performs a comprehensive study on the deep-learning-based computer-aided diagnosis (CADx) for the differential diagnosis of benign and malignant nodules/lesions by avoiding the potential errors caused by inaccurate image processing results (e.g., boundary segmentation), as well as the classification bias resulting from a less robust feature set, as involved in most conventional CADx algorithms. Specifically, the stacked denoising auto-encoder (SDAE) is exploited on the two CADx applications for the differentiation of breast ultrasound lesions and lung CT nodules. The SDAE architecture is well equipped with the automatic feature exploration mechanism and noise tolerance advantage, and hence may be suitable to deal with the intrinsically noisy property of medical image data from various imaging modalities. To show the outperformance of SDAE-based CADx over the conventional scheme, two latest conventional CADx algorithms are implemented for comparison. 10 times of 10-fold cross-validations are conducted to illustrate the efficacy of the SDAE-based CADx algorithm. The experimental results show the significant performance boost by the SDAE-based CADx algorithm over the two conventional methods, suggesting that deep learning techniques can potentially change the design paradigm of the CADx systems without the need of explicit design and selection of problem-oriented features.

  12. Computer-Aided Diagnosis with Deep Learning Architecture: Applications to Breast Lesions in US Images and Pulmonary Nodules in CT Scans.

    PubMed

    Cheng, Jie-Zhi; Ni, Dong; Chou, Yi-Hong; Qin, Jing; Tiu, Chui-Mei; Chang, Yeun-Chung; Huang, Chiun-Sheng; Shen, Dinggang; Chen, Chung-Ming

    2016-01-01

    This paper performs a comprehensive study on the deep-learning-based computer-aided diagnosis (CADx) for the differential diagnosis of benign and malignant nodules/lesions by avoiding the potential errors caused by inaccurate image processing results (e.g., boundary segmentation), as well as the classification bias resulting from a less robust feature set, as involved in most conventional CADx algorithms. Specifically, the stacked denoising auto-encoder (SDAE) is exploited on the two CADx applications for the differentiation of breast ultrasound lesions and lung CT nodules. The SDAE architecture is well equipped with the automatic feature exploration mechanism and noise tolerance advantage, and hence may be suitable to deal with the intrinsically noisy property of medical image data from various imaging modalities. To show the outperformance of SDAE-based CADx over the conventional scheme, two latest conventional CADx algorithms are implemented for comparison. 10 times of 10-fold cross-validations are conducted to illustrate the efficacy of the SDAE-based CADx algorithm. The experimental results show the significant performance boost by the SDAE-based CADx algorithm over the two conventional methods, suggesting that deep learning techniques can potentially change the design paradigm of the CADx systems without the need of explicit design and selection of problem-oriented features. PMID:27079888

  13. Computer-Aided Diagnosis with Deep Learning Architecture: Applications to Breast Lesions in US Images and Pulmonary Nodules in CT Scans.

    PubMed

    Cheng, Jie-Zhi; Ni, Dong; Chou, Yi-Hong; Qin, Jing; Tiu, Chui-Mei; Chang, Yeun-Chung; Huang, Chiun-Sheng; Shen, Dinggang; Chen, Chung-Ming

    2016-04-15

    This paper performs a comprehensive study on the deep-learning-based computer-aided diagnosis (CADx) for the differential diagnosis of benign and malignant nodules/lesions by avoiding the potential errors caused by inaccurate image processing results (e.g., boundary segmentation), as well as the classification bias resulting from a less robust feature set, as involved in most conventional CADx algorithms. Specifically, the stacked denoising auto-encoder (SDAE) is exploited on the two CADx applications for the differentiation of breast ultrasound lesions and lung CT nodules. The SDAE architecture is well equipped with the automatic feature exploration mechanism and noise tolerance advantage, and hence may be suitable to deal with the intrinsically noisy property of medical image data from various imaging modalities. To show the outperformance of SDAE-based CADx over the conventional scheme, two latest conventional CADx algorithms are implemented for comparison. 10 times of 10-fold cross-validations are conducted to illustrate the efficacy of the SDAE-based CADx algorithm. The experimental results show the significant performance boost by the SDAE-based CADx algorithm over the two conventional methods, suggesting that deep learning techniques can potentially change the design paradigm of the CADx systems without the need of explicit design and selection of problem-oriented features.

  14. Computer-Aided Diagnosis with Deep Learning Architecture: Applications to Breast Lesions in US Images and Pulmonary Nodules in CT Scans

    PubMed Central

    Cheng, Jie-Zhi; Ni, Dong; Chou, Yi-Hong; Qin, Jing; Tiu, Chui-Mei; Chang, Yeun-Chung; Huang, Chiun-Sheng; Shen, Dinggang; Chen, Chung-Ming

    2016-01-01

    This paper performs a comprehensive study on the deep-learning-based computer-aided diagnosis (CADx) for the differential diagnosis of benign and malignant nodules/lesions by avoiding the potential errors caused by inaccurate image processing results (e.g., boundary segmentation), as well as the classification bias resulting from a less robust feature set, as involved in most conventional CADx algorithms. Specifically, the stacked denoising auto-encoder (SDAE) is exploited on the two CADx applications for the differentiation of breast ultrasound lesions and lung CT nodules. The SDAE architecture is well equipped with the automatic feature exploration mechanism and noise tolerance advantage, and hence may be suitable to deal with the intrinsically noisy property of medical image data from various imaging modalities. To show the outperformance of SDAE-based CADx over the conventional scheme, two latest conventional CADx algorithms are implemented for comparison. 10 times of 10-fold cross-validations are conducted to illustrate the efficacy of the SDAE-based CADx algorithm. The experimental results show the significant performance boost by the SDAE-based CADx algorithm over the two conventional methods, suggesting that deep learning techniques can potentially change the design paradigm of the CADx systems without the need of explicit design and selection of problem-oriented features. PMID:27079888

  15. Computer aided detection system for clustered microcalcifications

    PubMed Central

    Ge, Jun; Hadjiiski, Lubomir M.; Sahiner, Berkman; Wei, Jun; Helvie, Mark A.; Zhou, Chuan; Chan, Heang-Ping

    2009-01-01

    We have developed a computer-aided detection (CAD) system to detect clustered microcalcification automatically on full-field digital mammograms (FFDMs) and a CAD system for screen-film mammograms (SFMs). The two systems used the same computer vision algorithms but their false positive (FP) classifiers were trained separately with sample images of each modality. In this study, we compared the performance of the CAD systems for detection of clustered microcalcifications on pairs of FFDM and SFM obtained from the same patient. For case-based performance evaluation, the FFDM CAD system achieved detection sensitivities of 70%, 80%, and 90% at an average FP cluster rate of 0.07, 0.16, and 0.63 per image, compared with an average FP cluster rate of 0.15, 0.38, and 2.02 per image for the SFM CAD system. The difference was statistically significant with the alternative free-response receiver operating characteristic (AFROC) analysis. When evaluated on data sets negative for microcalcification clusters, the average FP cluster rates of the FFDM CAD system were 0.04, 0.11, and 0.33 per image at detection sensitivity level of 70%, 80%, and 90%, compared with an average FP cluster rate of 0.08, 0.14, and 0.50 per image for the SFM CAD system. When evaluated for malignant cases only, the difference of the performance of the two CAD systems was not statistically significant with AFROC analysis. PMID:17264365

  16. Issues of a Computer-Aided Design of Hydraulic Jacks

    NASA Astrophysics Data System (ADS)

    Averchenkov, V. I.; Averchenkov, A. V.; Kolyakinand, V. V.; Orekhov, O. D.

    2016-04-01

    The article deals with the issues of a computer-aided design of hydraulic equipment, namely hydraulic jacks. Design principles of the hydraulic jack CAD system are described. In addition, the possibilities for the system improvement and expansion are considered.

  17. Noninvasive differential diagnosis of dental periapical lesions in cone-beam CT scans

    SciTech Connect

    Okada, Kazunori; Rysavy, Steven; Flores, Arturo; Linguraru, Marius George

    2015-04-15

    Purpose: This paper proposes a novel application of computer-aided diagnosis (CAD) to an everyday clinical dental challenge: the noninvasive differential diagnosis of periapical lesions between periapical cysts and granulomas. A histological biopsy is the most reliable method currently available for this differential diagnosis; however, this invasive procedure prevents the lesions from healing noninvasively despite a report that they may heal without surgical treatment. A CAD using cone-beam computed tomography (CBCT) offers an alternative noninvasive diagnostic tool which helps to avoid potentially unnecessary surgery and to investigate the unknown healing process and rate for the lesions. Methods: The proposed semiautomatic solution combines graph-based random walks segmentation with machine learning-based boosted classifiers and offers a robust clinical tool with minimal user interaction. As part of this CAD framework, the authors provide two novel technical contributions: (1) probabilistic extension of the random walks segmentation with likelihood ratio test and (2) LDA-AdaBoost: a new integration of weighted linear discriminant analysis to AdaBoost. Results: A dataset of 28 CBCT scans is used to validate the approach and compare it with other popular segmentation and classification methods. The results show the effectiveness of the proposed method with 94.1% correct classification rate and an improvement of the performance by comparison with the Simon’s state-of-the-art method by 17.6%. The authors also compare classification performances with two independent ground-truth sets from the histopathology and CBCT diagnoses provided by endodontic experts. Conclusions: Experimental results of the authors show that the proposed CAD system behaves in clearer agreement with the CBCT ground-truth than with histopathology, supporting the Simon’s conjecture that CBCT diagnosis can be as accurate as histopathology for differentiating the periapical lesions.

  18. [The ultrasonic demonstration of gas in the endometrial cavity--an aid for the diagnosis of puerperal endometritis].

    PubMed

    Piek, P C; Fuchs, N; Venter, P F; van der Merwe, C A; Koch, Z

    1989-09-01

    A pilot study was undertaken to determine the prevalence of gas in the puerperal endometrial cavity and to determine whether this finding has any relationship to the mode of delivery or to the development of puerperal endometritis. On the first day after delivery 192 patients were examinee ultrasonographically and gas was demonstrated in 26 (13.54%). Gas was found significantly more often in relation to caesarean section and intra-uterine manipulation than in normal vaginal deliveries (P less than 0.0001). On the third puerperal day the gas disappeared in 12 patients but persisted in 14, of whom 7 had signs of endometritis. Endometritis was diagnosed in a total of 8 patients and only 1 did not have signs of gas in the endometrial cavity. Although the figures are small it is concluded that ultrasonography of the puerperal uterus might assist in the diagnosis of puerperal endometritis. PMID:2672375

  19. 2014 CODEPEH recommendations: Early detection of late onset deafness, audiological diagnosis, hearing aid fitting and early intervention.

    PubMed

    Núñez-Batalla, Faustino; Jáudenes-Casaubón, Carmen; Sequí-Canet, Jose Miguel; Vivanco-Allende, Ana; Zubicaray-Ugarteche, Jose

    2016-01-01

    The latest scientific literature considers early diagnosis of deafness as the key element to define the educational and inclusive prognosis of the deaf child, because it allows taking advantage of the critical period of development (0-4 years). Highly significant differences exist between deaf people who have been stimulated early and those who have received late or improper intervention. Early identification of late-onset disorders requires special attention and knowledge on the part of every childcare professional. Programs and additional actions beyond neonatal screening should be designed and planed to ensure that every child with a significant hearing loss is detected early. For this purpose, the CODEPEH would like to highlight the need for continuous monitoring of children's auditory health. Consequently, CODEPEH has drafted the recommendations included in the present document.

  20. Validation of a Blood-Based Laboratory Test to Aid in the Confirmation of a Diagnosis of Schizophrenia

    PubMed Central

    Schwarz, Emanuel; Izmailov, Rauf; Spain, Michael; Barnes, Anthony; Mapes, James P.; Guest, Paul C.; Rahmoune, Hassan; Pietsch, Sandra; Leweke, F. Markus; Rothermundt, Matthias; Steiner, Johann; Koethe, Dagmar; Kranaster, Laura; Ohrmann, Patricia; Suslow, Thomas; Levin, Yishai; Bogerts, Bernhard; van Beveren, Nico (JM); McAllister, George; Weber, Natalya; Niebuhr, David; Cowan, David; Yolken, Robert H.; Bahn, Sabine

    2010-01-01

    We describe the validation of a serum-based test developed by Rules-Based Medicine which can be used to help confirm the diagnosis of schizophrenia. In preliminary studies using multiplex immunoassay profiling technology, we identified a disease signature comprised of 51 analytes which could distinguish schizophrenia (n = 250) from control (n = 230) subjects. In the next stage, these analytes were developed as a refined 51-plex immunoassay panel for validation using a large independent cohort of schizophrenia (n = 577) and control (n = 229) subjects. The resulting test yielded an overall sensitivity of 83% and specificity of 83% with a receiver operating characteristic area under the curve (ROC-AUC) of 89%. These 51 immunoassays and the associated decision rule delivered a sensitive and specific prediction for the presence of schizophrenia in patients compared to matched healthy controls. PMID:20520744

  1. Flexible Concurrency Control for Legacy CAD to Construct Collaborative CAD Environment

    NASA Astrophysics Data System (ADS)

    Cai, Xiantao; Li, Xiaoxia; He, Fazhi; Han, Soonhung; Chen, Xiao

    Collaborative CAD (Co-CAD) systems can be constructed based on either 3D kernel or legacy stand-alone CAD systems, which are typically commercial CAD systems such as CATIA, Pro/E and so on. Most of synchronous Co-CAD systems, especially these based on legacy stand-alone CAD systems, adopt the lock mechanism or the floor control as concurrency controls which are very restrictive and stagnant. A flexible concurrency control method is proposed to support the flexible concurrency control in Co-CAD systems based on legacy stand-alone CAD systems. At first, a model of operation relationship is proposed with special consideration for the concurrency control of these kinds of Co-CAD system. Then two types of data structure, the Collaborative Feature Dependent Graph (Co-FDG) and the Collaborative Feature Operational List (Co-FOL), are presented as the cornerstone of flexible concurrency control. Next a Flexible Concurrency Control Algorithm (FCCA) is proposed. Finally a Selective Undo/Redo Algorithm is proposed which can improve the flexibility of Co-CAD furthermore.

  2. Evaluation of a computer-aided detection algorithm for timely diagnosis of small acute intracranial hemorrhage on computed tomography in a critical care environment

    NASA Astrophysics Data System (ADS)

    Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

    2009-02-01

    Detection of acute intracranial hemorrhage (AIH) is a primary task in the interpretation of computed tomography (CT) brain scans of patients suffering from acute neurological disturbances or after head trauma. Interpretation can be difficult especially when the lesion is inconspicuous or the reader is inexperienced. We have previously developed a computeraided detection (CAD) algorithm to detect small AIH. One hundred and thirty five small AIH CT studies from the Los Angeles County (LAC) + USC Hospital were identified and matched by age and sex with one hundred and thirty five normal studies. These cases were then processed using our AIH CAD system to evaluate the efficacy and constraints of the algorithm.

  3. Advances in noninvasive detection of CAD

    SciTech Connect

    Kahn, J.K. )

    1991-04-01

    Advances in the noninvasive detection of myocardial ischemia are increasing our ability to diagnose coronary artery disease (CAD). Tomographic (SPECT) thallium imaging provides better identification of coronary arteries with atherosclerotic narrowing. Increased lung thallium uptake and transient ischemic dilatation of the heart are additional markers of severe CAD. Late thallium imaging, as well as reinjection imaging, provides more accurate identification of myocardial ischemia. Finally, new myocardial imaging agents, such as technetium Tc 99m sestamibi (Cardiolite), should improve detection of CAD by noninvasive methods.10 references.

  4. Engineering Technology Programs Courses Guide for Computer Aided Design and Computer Aided Manufacturing.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Div. of Vocational Education.

    This guide describes the requirements for courses in computer-aided design and computer-aided manufacturing (CAD/CAM) that are part of engineering technology programs conducted in vocational-technical schools in Georgia. The guide is organized in five sections. The first section provides a rationale for occupations in design and in production,…

  5. Fabrication of the mandibular implant-supported fixed restoration using CAD/CAM technology: a clinical report.

    PubMed

    Reshad, Mamaly; Cascione, Domenico; Aalam, Alexandre Amir

    2009-11-01

    The mandibular implant-supported fixed restoration is an appropriate treatment choice for patients with inadequate bone volume in the posterior mandible. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has broadened the scope and application for this treatment option. A milled titanium bar retaining individual all-ceramic zirconium oxide crowns, with composite resin replicating gingival tissues, is recommended as an acceptable variation for this type of prosthesis. An alternative method for fabricating a mandibular implant-supported fixed restoration using CAD/CAM technology is described.

  6. CAD system for footwear design based on whole real 3D data of last surface

    NASA Astrophysics Data System (ADS)

    Song, Wanzhong; Su, Xianyu

    2000-10-01

    Two major parts of application of CAD in footwear design are studied: the development of last surface; computer-aided design of planar shoe-template. A new quasi-experiential development algorithm of last surface based on triangulation approximation is presented. This development algorithm consumes less time and does not need any interactive operation for precisely development compared with other development algorithm of last surface. Based on this algorithm, a software, SHOEMAKERTM, which contains computer aided automatic measurement, automatic development of last surface and computer aide design of shoe-template has been developed.

  7. Mechanical design productivity using CAD graphics - A user's point of view

    NASA Astrophysics Data System (ADS)

    Boltz, R. J.; Avery, J. T., Jr.

    1985-02-01

    The present investigation is concerned with the mechanical design productivity resulting from the use of Computer-Aided Design (CAD) graphics as a design tool. The considered studies had been conducted by a company which is involved in the design, development, and manufacture of government and defense products. Attention is given to CAD graphics for mechanical design, productivity, an overall productivity assessment, the use of CAD graphics for basic mechanical design, productivity in engineering-related areas, and an overall engineering productivity assessment. The investigation shows that there was no appreciable improvement in productivity with respect to basic mechanical design. However, rather substantial increases could be realized in productivity for engineering-related activities.

  8. A fully automated multi-modal computer aided diagnosis approach to coronary calcium scoring of MSCT images

    NASA Astrophysics Data System (ADS)

    Wu, Jing; Ferns, Gordon; Giles, John; Lewis, Emma

    2012-03-01

    Inter- and intra- observer variability is a problem often faced when an expert or observer is tasked with assessing the severity of a disease. This issue is keenly felt in coronary calcium scoring of patients suffering from atherosclerosis where in clinical practice, the observer must identify firstly the presence, followed by the location of candidate calcified plaques found within the coronary arteries that may prevent oxygenated blood flow to the heart muscle. However, it can be difficult for a human observer to differentiate calcified plaques that are located in the coronary arteries from those found in surrounding anatomy such as the mitral valve or pericardium. In addition to the benefits to scoring accuracy, the use of fast, low dose multi-slice CT imaging to perform the cardiac scan is capable of acquiring the entire heart within a single breath hold. Thus exposing the patient to lower radiation dose, which for a progressive disease such as atherosclerosis where multiple scans may be required, is beneficial to their health. Presented here is a fully automated method for calcium scoring using both the traditional Agatston method, as well as the volume scoring method. Elimination of the unwanted regions of the cardiac image slices such as lungs, ribs, and vertebrae is carried out using adaptive heart isolation. Such regions cannot contain calcified plaques but can be of a similar intensity and their removal will aid detection. Removal of both the ascending and descending aortas, as they contain clinical insignificant plaques, is necessary before the final calcium scores are calculated and examined against ground truth scores of three averaged expert observer results. The results presented here are intended to show the feasibility and requirement for an automated scoring method to reduce the subjectivity and reproducibility error inherent with manual clinical calcium scoring.

  9. A Computer-Aided Diagnosis System for Measuring Carotid Artery Intima-Media Thickness (IMT) Using Quaternion Vectors.

    PubMed

    Kutbay, Uğurhan; Hardalaç, Fırat; Akbulut, Mehmet; Akaslan, Ünsal; Serhatlıoğlu, Selami

    2016-06-01

    This study aims investigating adjustable distant fuzzy c-means segmentation on carotid Doppler images, as well as quaternion-based convolution filters and saliency mapping procedures. We developed imaging software that will simplify the measurement of carotid artery intima-media thickness (IMT) on saliency mapping images. Additionally, specialists evaluated the present images and compared them with saliency mapping images. In the present research, we conducted imaging studies of 25 carotid Doppler images obtained by the Department of Cardiology at Fırat University. After implementing fuzzy c-means segmentation and quaternion-based convolution on all Doppler images, we obtained a model that can be analyzed easily by the doctors using a bottom-up saliency model. These methods were applied to 25 carotid Doppler images and then interpreted by specialists. In the present study, we used color-filtering methods to obtain carotid color images. Saliency mapping was performed on the obtained images, and the carotid artery IMT was detected and interpreted on the obtained images from both methods and the raw images are shown in Results. Also these results were investigated by using Mean Square Error (MSE) for the raw IMT images and the method which gives the best performance is the Quaternion Based Saliency Mapping (QBSM). 0,0014 and 0,000191 mm(2) MSEs were obtained for artery lumen diameters and plaque diameters in carotid arteries respectively. We found that computer-based image processing methods used on carotid Doppler could aid doctors' in their decision-making process. We developed software that could ease the process of measuring carotid IMT for cardiologists and help them to evaluate their findings. PMID:27137786

  10. Cad Graphics in Facilities Planning.

    ERIC Educational Resources Information Center

    Collier, Linda M.

    1984-01-01

    By applying a computer-aided drafting system to a range of facilities layouts and plans, a division of Tektronix, Inc., Oregon, is maintaining staffing levels with an added workload. The tool is also being used in other areas of the company for illustration, design, and administration. (MLF)

  11. CADS:Cantera Aerosol Dynamics Simulator.

    SciTech Connect

    Moffat, Harry K.

    2007-07-01

    This manual describes a library for aerosol kinetics and transport, called CADS (Cantera Aerosol Dynamics Simulator), which employs a section-based approach for describing the particle size distributions. CADS is based upon Cantera, a set of C++ libraries and applications that handles gas phase species transport and reactions. The method uses a discontinuous Galerkin formulation to represent the particle distributions within each section and to solve for changes to the aerosol particle distributions due to condensation, coagulation, and nucleation processes. CADS conserves particles, elements, and total enthalpy up to numerical round-off error, in all of its formulations. Both 0-D time dependent and 1-D steady state applications (an opposing-flow flame application) have been developed with CADS, with the initial emphasis on developing fundamental mechanisms for soot formation within fires. This report also describes the 0-D application, TDcads, which models a time-dependent perfectly stirred reactor.

  12. The CAD-EGS Project: Using CAD Geometrics in EGS4

    SciTech Connect

    Langeveld, Willy G.J.

    2002-03-28

    The objective of the CAD-EGS project is to provide a way to use a CAD system to create 3D geometries for use within EGS4. In this report, we describe an approach based on an intermediate file, written out by the CAD system, that is read by an EGS4 user code designed for the purpose. A prototype solution was implemented using a commonly used CAD system and the Virtual Reality Modeling Language (VRML) as an intermediate file format. We report results from the prototype, and discuss various problems arising from both the approach and the particular choices made.

  13. A critically appraised topic review of computer-aided design/computer-aided machining of removable partial denture frameworks.

    PubMed

    Lang, Lisa A; Tulunoglu, Ibrahim

    2014-01-01

    A critically appraised topic (CAT) review is presented about the use of computer-aided design (CAD)/computer-aided machining (CAM) removable partial denture (RPD) frameworks. A systematic search of the literature supporting CAD/CAM RPD systems revealed no randomized clinical trials, hence the CAT review was performed. A PubMed search yielded 9 articles meeting the inclusion criteria. Each article was characterized by study design and level of evidence. No clinical outcomes research has been published on the use of CAD/CAM RPDs. Low levels of evidence were found in the available literature. Clinical research studies are needed to determine the efficacy of this treatment modality.

  14. AutoCAD-To-NASTRAN Translator Program

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1989-01-01

    Program facilitates creation of finite-element mathematical models from geometric entities. AutoCAD to NASTRAN translator (ACTON) computer program developed to facilitate quick generation of small finite-element mathematical models for use with NASTRAN finite-element modeling program. Reads geometric data of drawing from Data Exchange File (DXF) used in AutoCAD and other PC-based drafting programs. Written in Microsoft Quick-Basic (Version 2.0).

  15. Potential reasons for differences in CAD effectiveness evaluated using laboratory and clinical studies

    NASA Astrophysics Data System (ADS)

    He, Xin; Samuelson, Frank; Zeng, Rongping; Sahiner, Berkman

    2015-03-01

    Research studies have investigated a number of factors that may impact the performance assessment of computer aided detection (CAD) effectiveness, such as the inherent design of the CAD, the image and reader samples, and the assessment methods. In this study, we focused on the effect of prevalence on cue validity (co-occurrence of cue and signal) and learning as potentially important factors in CAD assessment. For example, the prevalence of cases with breast cancer is around 50% in laboratory CAD studies, which is 100 times higher than that in breast cancer screening. Although ROC is prevalence-independent, an observer's use of CAD involves tasks that are more complicated than binary classification, including: search, detection, classification, cueing and learning. We developed models to investigate the potential impact of prevalence on cue validity and the learning of cue validity tasks. We hope this work motivates new studies that investigate previously under-explored factors involved in image interpretation with a new modality in its assessment.

  16. Analysis of breast CT lesions using computer-aided diagnosis: an application of neural networks on extracted morphologic and texture features

    NASA Astrophysics Data System (ADS)

    Ray, Shonket; Prionas, Nicolas D.; Lindfors, Karen K.; Boone, John M.

    2012-03-01

    Dedicated cone-beam breast CT (bCT) scanners have been developed as a potential alternative imaging modality to conventional X-ray mammography in breast cancer diagnosis. As with other modalities, quantitative imaging (QI) analysis can potentially be utilized as a tool to extract useful numeric information concerning diagnosed lesions from high quality 3D tomographic data sets. In this work, preliminary QI analysis was done by designing and implementing a computer-aided diagnosis (CADx) system consisting of image preprocessing, object(s) of interest (i.e. masses, microcalcifications) segmentation, structural analysis of the segmented object(s), and finally classification into benign or malignant disease. Image sets were acquired from bCT patient scans with diagnosed lesions. Iterative watershed segmentation (IWS), a hybridization of the watershed method using observer-set markers and a gradient vector flow (GVF) approach, was used as the lesion segmentation method in 3D. Eight morphologic parameters and six texture features based on gray level co-occurrence matrix (GLCM) calculations were obtained per segmented lesion and combined into multi-dimensional feature input data vectors. Artificial neural network (ANN) classifiers were used by performing cross validation and network parameter optimization to maximize area under the curve (AUC) values of the resulting receiver-operating characteristic (ROC) curves. Within these ANNs, biopsy-proven diagnoses of malignant and benign lesions were recorded as target data while the feature vectors were saved as raw input data. With the image data separated into post-contrast (n = 55) and pre-contrast sets (n = 39), a maximum AUC of 0.70 +/- 0.02 and 0.80 +/- 0.02 were achieved, respectively, for each data set after ANN application.

  17. [THE RESULTS OF IMPLEMENTATION OF THE INTERNATIONAL BANK FOR RECONSTRUCTION AND DEVELOPMENT LOAN PROJECT "PREVENTION, DIAGNOSIS, AND TREATMENT OF TUBERCULOSIS AND AIDS", A "TUBERCULOSIS" COMPONENT].

    PubMed

    2010-01-01

    Due to the implementation of the International Bank for Reconstruction and Development (IBRD) loan project "Prevention, diagnosis, treatment of tuberculosis and AIDS", a "Tuberculosis" component that is an addition to the national tuberculosis control program in 15 subjects of the Russian Federation, followed up by the Central Research Institute of Tuberculosis, Russian Academy of Medical Sciences, the 2005-2008 measures stipulated by the Project have caused substantial changes in the organization of tuberculosis control: implementation of Orders Nos. 109, 50, and 690 and supervision of their implementation; modernization of the laboratories of the general medical network and antituberbulosis service (404 kits have been delivered for clinical diagnostic laboratories and 12 for bacteriological laboratories, including BACTEC 960 that has been provided in 6 areas); 91 training seminars have been held at the federal and regional levels; 1492 medical workers have been trained in the detection, diagnosis, and treatment of patients with tuberculosis; 8 manuals and guidelines have been prepared and sent to all areas. In the period 2005-2008, the tuberculosis morbidity and mortality rates in the followed-up areas reduced by 1.2 and 18.6%, respectively. The analysis of patient cohorts in 2007 and 2005 revealed that the therapeutic efficiency evaluated from sputum smear microscopy increased by 16.3%; there were reductions in the proportion of patients having ineffective chemotherapy (from 16.1 to 11.1%), patients who died from tuberculosis (from 11.6 to 9.9%), and those who interrupted therapy ahead of time (from 11.8 to 7.8%). Implementation of the IBR project has contributed to the improvement of the national strategy and the enhancement of the efficiency of tuberculosis control.

  18. Advanced Geologic Modeling Using CAD and Unstructured Meshes

    NASA Astrophysics Data System (ADS)

    Melnikova, Y.; Jacquemyn, C.; Osman, H.; Gorman, G.; Hampson, G.; Jackson, M.

    2015-12-01

    Capturing complex, multiscale geologic heterogeneity in subsurface flow models is challenging. Surface-based modeling (SBM) offers an alternative approach to conventional grid-based methods. In SBM, all geologic features that impact the distribution of material properties, such as porosity and permeability, are modeled as volumes bounded by surfaces. Within these volumes, termed geologic domains, the material properties are constant. A typical model contains numerous such domains. The surfaces have parametric, grid-free representation which, in principle, allows for unlimited complexity, since no resolution is implied at the stage of modeling and features of any scale can be included. We demonstrate a method to create stochastic, surface-based models using computer aided design (CAD) and efficiently discretise them for flow simulation. The surfaces are represented using non-uniform, rational B-splines (NURBS), and processed in a CAD environment employing Boolean operations. We show examples of fluvial channels, fracture networks and scour events. Cartesian-like grids are not able to capture the complex geometries in these models without using excessively large numbers of grid blocks. Unstructured meshes can more efficiently approximate the geometries. However, high aspect ratio features and varying curvatures present challenges for algorithms to produce quality, unstructured meshes without excessive user interaction. We contribute an automated integrated workflow that processes the input geometry created in the CAD environment, creates the final model, and discretises it with a quality tetrahedral mesh. For computational efficiency, we use a geometry-adaptive mesh that distributes the element density and size in accordance with the geometrical complexity of the model. We show examples of finite-element flow simulations of the resulting geologic models. The new approach has broad application in modeling subsurface flow.

  19. Bridging CAGD knowledge into CAD/CG applications: Mathematical theories as stepping stones of innovations

    NASA Astrophysics Data System (ADS)

    Gobithaasan, R. U.; Miura, Kenjiro T.; Hassan, Mohamad Nor

    2014-07-01

    Computer Aided Geometric Design (CAGD) which surpasses the underlying theories of Computer Aided Design (CAD) and Computer Graphics (CG) has been taught in a number of Malaysian universities under the umbrella of Mathematical Sciences' faculty/department. On the other hand, CAD/CG is taught either under the Engineering or Computer Science Faculty. Even though CAGD researchers/educators/students (denoted as contributors) have been enriching this field of study by means of article/journal publication, many fail to convert the idea into constructive innovation due to the gap that occurs between CAGD contributors and practitioners (engineers/product/designers/architects/artists). This paper addresses this issue by advocating a number of technologies that can be used to transform CAGD contributors into innovators where immediate impact in terms of practical application can be experienced by the CAD/CG practitioners. The underlying principle of solving this issue is twofold. First would be to expose the CAGD contributors on ways to turn mathematical ideas into plug-ins and second is to impart relevant CAGD theories to CAD/CG to practitioners. Both cases are discussed in detail and the final section shows examples to illustrate the importance of turning mathematical knowledge into innovations.

  20. Comparison of CAD-CAM and hand made sockets for PTB prostheses.

    PubMed

    Köhler, P; Lindh, L; Netz, P

    1989-04-01

    The aim of the present study was to compare sockets for below-knee (BK) prostheses made by Computer Aided Design-Computer Aided Manufacture (CAD-CAM) to those made by hand. The patients in the study were provided with two prostheses each, which apart from the sockets, were identical. One socket was made by the CAD-CAM technique developed at the Bioengineering Centre, Roehampton, University College London and one was made by hand at the OT-Centre, Stockholm, Sweden. The results were based on investigation of eight unilateral below-knee amputees evaluating their own sockets by Visual Analogous Scale with respect to comfort, pressure, and pain. The sockets were evaluated on seven occasions, at two tests, on delivery, after use every second day for six days and every second week for two weeks. All CAD-CAM sockets except one had to be changed once as compared to the hand made of which only two had to be changed. As to comfort it could not be demonstrated that there was any significant difference between the two types of sockets and both types were well accepted by all patients. Differences in pressure and pain were rarely reported. There were obvious differences between the two types of socket with respect to height, width, and inner surface configuration. The authors feel that CAD-CAM will in the near future be an excellent tool for design and manufacture of prosthetic sockets.

  1. Combining Feature Extraction Methods to Assist the Diagnosis of Alzheimer's Disease.

    PubMed

    Segovia, F; Górriz, J M; Ramírez, J; Phillips, C; For The Alzheimer's Disease Neuroimaging Initiative

    2016-01-01

    Neuroimaging data as (18)F-FDG PET is widely used to assist the diagnosis of Alzheimer's disease (AD). Looking for regions with hypoperfusion/ hypometabolism, clinicians may predict or corroborate the diagnosis of the patients. Modern computer aided diagnosis (CAD) systems based on the statistical analysis of whole neuroimages are more accurate than classical systems based on quantifying the uptake of some predefined regions of interests (ROIs). In addition, these new systems allow determining new ROIs and take advantage of the huge amount of information comprised in neuroimaging data. A major branch of modern CAD systems for AD is based on multivariate techniques, which analyse a neuroimage as a whole, considering not only the voxel intensities but also the relations among them. In order to deal with the vast dimensionality of the data, a number of feature extraction methods have been successfully applied. In this work, we propose a CAD system based on the combination of several feature extraction techniques. First, some commonly used feature extraction methods based on the analysis of the variance (as principal component analysis), on the factorization of the data (as non-negative matrix factorization) and on classical magnitudes (as Haralick features) were simultaneously applied to the original data. These feature sets were then combined by means of two different combination approaches: i) using a single classifier and a multiple kernel learning approach and ii) using an ensemble of classifier and selecting the final decision by majority voting. The proposed approach was evaluated using a labelled neuroimaging database along with a cross validation scheme. As conclusion, the proposed CAD system performed better than approaches using only one feature extraction technique. We also provide a fair comparison (using the same database) of the selected feature extraction methods. PMID:26567734

  2. Trypanosoma cruzi necrotizing meningoencephalitis in a Venezuelan HIV⁺-AIDS patient: pathological diagnosis confirmed by PCR using formalin-fixed- and paraffin-embedded-tissues.

    PubMed

    Rossi Spadafora, Marcello Salvatore; Céspedes, Ghislaine; Romero, Sandra; Fuentes, Isabel; Boada-Sucre, Alpidio A; Cañavate, Carmen; Flores-Chávez, María

    2014-01-01

    Coinfections with human immunodeficiency virus (HIV) and infectious agents have been recognized since the early 90s. In the central nervous system (CNS) of HIV(+) patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL) developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS) and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE) and meningoencephalitis (NME). The present work aims to present a Venezuelan case of NME associated with the coinfection of HIV and a T. cruzi-like trypanosomatid as well as its evolution and diagnosis by histopathological techniques, electron microscopy, and PCR methods using formalin-fixed- (FF-) and paraffin-embedded- (PE-) tissues. Postmortem cytological studies of leptomeninges imprints reveal the presence of trypomastigotes of Trypanosoma sp. Histopathological and electron microscopy studies allowed us to identify an amastigote stage and to reject the involvement of other opportunistic microorganisms as the etiological agent of the SOL. The definitive confirmation of T. cruzi as the etiological agent was achieved by PCR suggesting that the NME by T. cruzi was due to a reactivation of Chagas' disease.

  3. Improving positive predictive value in computer-aided diagnosis using mammographic mass and microcalcification confidence score fusion based on co-location information

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Kim, Dae Hoe; Choi, Jae Young; Ro, Yong Man

    2013-02-01

    In this study, a novel fusion framework has been developed to combine the detection of both breast masses and microcalcifications (MCs), aiming to improve positive predictive value (PPV) in Computer-aided Diagnosis (CADx). Clinically, it has been widely accepted that a mass associated with MC is a useful indicator of predicting the malignancy of the mass. In light of this fact, given that a mass and MCs are co-located each other (i.e., they are at the same location), the proposed fusion framework combines confidence scores of the mass and MCs for the purpose of improving the probability that the mass is malignant. To this end, the popular Bayesian network model is applied to effectively combine the detection confidence scores and to achieve higher accuracy for malignant mass classification. To demonstrate the effectiveness of the proposed fusion framework, 31 mammograms were collected from the public DDSM database. The proposed fusion framework can increase the area under the receiver operating characteristic curve (AUC) from 0.7939 to 0.8806, and the partial area index (PAUC) above the sensitivity of 0.9 from 0.1270 to 0.2280, compared to the CADx system without exploiting co-location information with MCs. Based on these results, it can be expected that the proposed fusion framework can be readily applied for realizing CADx systems with the higher PPV.

  4. Trypanosoma cruzi Necrotizing Meningoencephalitis in a Venezuelan HIV+-AIDS Patient: Pathological Diagnosis Confirmed by PCR Using Formalin-Fixed- and Paraffin-Embedded-Tissues

    PubMed Central

    Rossi Spadafora, Marcello Salvatore; Céspedes, Ghislaine; Romero, Sandra; Fuentes, Isabel; Boada-Sucre, Alpidio A.; Cañavate, Carmen; Flores-Chávez, María

    2014-01-01

    Coinfections with human immunodeficiency virus (HIV) and infectious agents have been recognized since the early 90s. In the central nervous system (CNS) of HIV+ patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL) developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS) and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE) and meningoencephalitis (NME). The present work aims to present a Venezuelan case of NME associated with the coinfection of HIV and a T. cruzi-like trypanosomatid as well as its evolution and diagnosis by histopathological techniques, electron microscopy, and PCR methods using formalin-fixed- (FF-) and paraffin-embedded- (PE-) tissues. Postmortem cytological studies of leptomeninges imprints reveal the presence of trypomastigotes of Trypanosoma sp. Histopathological and electron microscopy studies allowed us to identify an amastigote stage and to reject the involvement of other opportunistic microorganisms as the etiological agent of the SOL. The definitive confirmation of T. cruzi as the etiological agent was achieved by PCR suggesting that the NME by T. cruzi was due to a reactivation of Chagas' disease. PMID:25763312

  5. Optimal neural network architecture selection: effects on computer-aided detection of mammographic microcalcifications

    NASA Astrophysics Data System (ADS)

    Gurcan, Metin N.; Chan, Heang-Ping; Sahiner, Berkman; Hadjiiski, Lubomir M.; Petrick, Nicholas; Helvie, Mark A.

    2002-05-01

    We evaluated the effectiveness of an optimal convolution neural network (CNN) architecture selected by simulated annealing for improving the performance of a computer-aided diagnosis (CAD) system designed for the detection of microcalcification clusters on digitized mammograms. The performances of the CAD programs with manually and optimally selected CNNs were compared using an independent test set. This set included 472 mammograms and contained 253 biopsy-proven malignant clusters. Free-response receiver operating characteristic (FROC) analysis was used for evaluation of the detection accuracy. At a false positive (FP) rate of 0.7 per image, the film-based sensitivity was 84.6% with the optimized CNN, in comparison with 77.2% with the manually selected CNN. If clusters having images in both craniocaudal and mediolateral oblique views were analyzed together and a cluster was considered to be detected when it was detected in one or both views, at 0.7 FPs/image, the sensitivity was 93.3% with the optimized CNN and 87.0% with the manually selected CNN. This study indicates that classification of true positive and FP signals is an important step of the CAD program and that the detection accuracy of the program can be considerably improved by optimizing this step with an automated optimization algorithm.

  6. Performance evaluation of NASA/KSC CAD/CAE graphics local area network

    NASA Technical Reports Server (NTRS)

    Zobrist, George

    1988-01-01

    This study had as an objective the performance evaluation of the existing CAD/CAE graphics network at NASA/KSC. This evaluation will also aid in projecting planned expansions, such as the Space Station project on the existing CAD/CAE network. The objectives were achieved by collecting packet traffic on the various integrated sub-networks. This included items, such as total number of packets on the various subnetworks, source/destination of packets, percent utilization of network capacity, peak traffic rates, and packet size distribution. The NASA/KSC LAN was stressed to determine the useable bandwidth of the Ethernet network and an average design station workload was used to project the increased traffic on the existing network and the planned T1 link. This performance evaluation of the network will aid the NASA/KSC network managers in planning for the integration of future workload requirements into the existing network.

  7. A computer assisted diagnosis tool for the classification of burns by depth of injury.

    PubMed

    Serrano, Carmen; Acha, Begoña; Gómez-Cía, Tomás; Acha, José I; Roa, Laura M

    2005-05-01

    In this paper, a computer assisted diagnosis (CAD) tool for the classification of burns into their depths is proposed. The aim of the system is to separate burn wounds from healthy skin, and to distinguish among the different types of burns (burn depths) by means of digital photographs. It is intended to be used as an aid to diagnosis in local medical centres, where there is a lack of specialists. Another potential use of the system is as an educational tool. The system is based on the analysis of digital photographs. It extracts from those images colour and texture information, as these are the characteristics observed by physicians in order to form a diagnosis. Clinical effectiveness of the method was demonstrated on 35 clinical burn wound images, yielding an average classification success rate of 88% compared to expert classified images.

  8. A computer assisted diagnosis tool for the classification of burns by depth of injury.

    PubMed

    Serrano, Carmen; Acha, Begoña; Gómez-Cía, Tomás; Acha, José I; Roa, Laura M

    2005-05-01

    In this paper, a computer assisted diagnosis (CAD) tool for the classification of burns into their depths is proposed. The aim of the system is to separate burn wounds from healthy skin, and to distinguish among the different types of burns (burn depths) by means of digital photographs. It is intended to be used as an aid to diagnosis in local medical centres, where there is a lack of specialists. Another potential use of the system is as an educational tool. The system is based on the analysis of digital photographs. It extracts from those images colour and texture information, as these are the characteristics observed by physicians in order to form a diagnosis. Clinical effectiveness of the method was demonstrated on 35 clinical burn wound images, yielding an average classification success rate of 88% compared to expert classified images. PMID:15774281

  9. Call for a Computer-Aided Cancer Detection and Classification Research Initiative in Oman.

    PubMed

    Mirzal, Andri; Chaudhry, Shafique Ahmad

    2016-01-01

    Cancer is a major health problem in Oman. It is reported that cancer incidence in Oman is the second highest after Saudi Arabia among Gulf Cooperation Council countries. Based on GLOBOCAN estimates, Oman is predicted to face an almost two-fold increase in cancer incidence in the period 2008-2020. However, cancer research in Oman is still in its infancy. This is due to the fact that medical institutions and infrastructure that play central roles in data collection and analysis are relatively new developments in Oman. We believe the country requires an organized plan and efforts to promote local cancer research. In this paper, we discuss current research progress in cancer diagnosis using machine learning techniques to optimize computer aided cancer detection and classification (CAD). We specifically discuss CAD using two major medical data, i.e., medical imaging and microarray gene expression profiling, because medical imaging like mammography, MRI, and PET have been widely used in Oman for assisting radiologists in early cancer diagnosis and microarray data have been proven to be a reliable source for differential diagnosis. We also discuss future cancer research directions and benefits to Oman economy for entering the cancer research and treatment business as it is a multi-billion dollar industry worldwide. PMID:27268600

  10. Call for a Computer-Aided Cancer Detection and Classification Research Initiative in Oman.

    PubMed

    Mirzal, Andri; Chaudhry, Shafique Ahmad

    2016-01-01

    Cancer is a major health problem in Oman. It is reported that cancer incidence in Oman is the second highest after Saudi Arabia among Gulf Cooperation Council countries. Based on GLOBOCAN estimates, Oman is predicted to face an almost two-fold increase in cancer incidence in the period 2008-2020. However, cancer research in Oman is still in its infancy. This is due to the fact that medical institutions and infrastructure that play central roles in data collection and analysis are relatively new developments in Oman. We believe the country requires an organized plan and efforts to promote local cancer research. In this paper, we discuss current research progress in cancer diagnosis using machine learning techniques to optimize computer aided cancer detection and classification (CAD). We specifically discuss CAD using two major medical data, i.e., medical imaging and microarray gene expression profiling, because medical imaging like mammography, MRI, and PET have been widely used in Oman for assisting radiologists in early cancer diagnosis and microarray data have been proven to be a reliable source for differential diagnosis. We also discuss future cancer research directions and benefits to Oman economy for entering the cancer research and treatment business as it is a multi-billion dollar industry worldwide.

  11. CBT Pilot Program Instructional Guide. Basic Drafting Skills Curriculum Delivered through CAD Workstations and Artificial Intelligence Software.

    ERIC Educational Resources Information Center

    Smith, Richard J.; Sauer, Mardelle A.

    This guide is intended to assist teachers in using computer-aided design (CAD) workstations and artificial intelligence software to teach basic drafting skills. The guide outlines a 7-unit shell program that may also be used as a generic authoring system capable of supporting computer-based training (CBT) in other subject areas. The first section…

  12. Multimodal image data fusion for Alzheimer's Disease diagnosis by sparse representation.

    PubMed

    Ortiz, Andrés; Fajardo, Daniel; Górriz, Juan M; Ramírez, Javier; Martínez-Murcia, Francisco J

    2014-01-01

    Alzheimer's Diasese (AD) diagnosis can be carried out by analysing functional or structural changes in the brain. Functional changes associated to neurological disorders can be figured out by positron emission tomography (PET) as it allows to study the activation of certain areas of the brain during specific task development. On the other hand, neurological disorders can also be discovered by analysing structural changes in the brain which are usually assessed by Magnetic Resonance Imaging (MRI). In fact, computer-aided diagnosis tools (CAD) that have been recently devised for the diagnosis of neurological disorders use functional or structural data. However, functional and structural data can be fused out in order to improve the accuracy and to diminish the false positive rate in CAD tools. In this paper we present a method for the diagnosis of AD which fuses multimodal image (PET and MRI) data by combining Sparse Representation Classifiers (SRC). The method presented in this work shows accuracy values up to 95% and clearly outperforms the classification outcomes obtained using single-modality images.

  13. Next Generation CAD/CAM/CAE Systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

    1997-01-01

    This document contains presentations from the joint UVA/NASA Workshop on Next Generation CAD/CAM/CAE Systems held at NASA Langley Research Center in Hampton, Virginia on March 18-19, 1997. The presentations focused on current capabilities and future directions of CAD/CAM/CAE systems, aerospace industry projects, and university activities related to simulation-based design. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the potential of emerging CAD/CAM/CAE technology for use in intelligent simulation-based design and to provide guidelines for focused future research leading to effective use of CAE systems for simulating the entire life cycle of aerospace systems.

  14. cadDX Operon of Streptococcus salivarius 57.I▿

    PubMed Central

    Chen, Yi-Ywan M.; Feng, C. W.; Chiu, C. F.; Burne, Robert A.

    2008-01-01

    A CadDX system that confers resistance to Cd2+ and Zn2+ was identified in Streptococcus salivarius 57.I. Unlike with other CadDX systems, the expression of the cad promoter was negatively regulated by CadX, and the repression was inducible by Cd2+ and Zn2+, similar to what was found for CadCA systems. The lower G+C content of the S. salivarius cadDX genes suggests acquisition by horizontal gene transfer. PMID:18165364

  15. cadDX operon of Streptococcus salivarius 57.I.

    PubMed

    Chen, Yi-Ywan M; Feng, C W; Chiu, C F; Burne, Robert A

    2008-03-01

    A CadDX system that confers resistance to Cd(2+) and Zn(2+) was identified in Streptococcus salivarius 57.I. Unlike with other CadDX systems, the expression of the cad promoter was negatively regulated by CadX, and the repression was inducible by Cd(2+) and Zn(2+), similar to what was found for CadCA systems. The lower G+C content of the S. salivarius cadDX genes suggests acquisition by horizontal gene transfer. PMID:18165364

  16. Application of computer-aided dispatch in law enforcement: An introductory planning guide

    NASA Technical Reports Server (NTRS)

    Sohn, R. L.; Gurfield, R. M.; Garcia, E. A.; Fielding, J. E.

    1975-01-01

    A set of planning guidelines for the application of computer-aided dispatching (CAD) to law enforcement is presented. Some essential characteristics and applications of CAD are outlined; the results of a survey of systems in the operational or planning phases are summarized. Requirements analysis, system concept design, implementation planning, and performance and cost modeling are described and demonstrated with numerous examples. Detailed descriptions of typical law enforcement CAD systems, and a list of vendor sources, are given in appendixes.

  17. Development of CAD prototype system for Crohn's disease

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Kitasaka, Takayuki; Furukawa, Kazuhiro; Watanabe, Osamu; Ando, Takafumi; Goto, Hidemi; Mori, Kensaku

    2010-03-01

    The purpose of this paper is to present a CAD prototype system for Crohn's disease. Crohn's disease causes inflammation or ulcers of the gastrointestinal tract. The number of patients of Crohn's disease is increasing in Japan. Symptoms of Crohn's disease include intestinal stenosis, longitudinal ulcers, and fistulae. Optical endoscope cannot pass through intestinal stenosis in some cases. We propose a new CAD system using abdominal fecal tagging CT images for efficient diagnosis of Crohn's disease. The system displays virtual unfolded (VU), virtual endoscopic, curved planar reconstruction, multi planar reconstruction, and outside views of both small and large intestines. To generate the VU views, we employ a small and large intestines extraction method followed by a simple electronic cleansing method. The intestine extraction is based on the region growing process, which uses a characteristic that tagged fluid neighbor air in the intestine. The electronic cleansing enables observation of intestinal wall under tagged fluid. We change the height of the VU views according to the perimeter of the intestine. In addition, we developed a method to enhance the longitudinal ulcer on views of the system. We enhance concave parts on the intestinal wall, which are caused by the longitudinal ulcer, based on local intensity structure analysis. We examined the small and the large intestines of eleven CT images by the proposed system. The VU views enabled efficient observation of the intestinal wall. The height change of the VU views helps finding intestinal stenosis on the VU views. The concave region enhancement made longitudinal ulcers clear on the views.

  18. The feasibility of using manual segmentation in a multifeature computer-aided diagnosis system for classification of skin lesions: a retrospective comparative study

    PubMed Central

    Huang, Adam; Chen, Yin-Chun; Lin, Chi-Wei; Tsai, John; Yang, Chung-Kai; Huang, Yin-Tseng; Wu, Yi-Fan; Chen, Gwo-Shing

    2015-01-01

    Objectives To investigate the feasibility of manual segmentation by users of different backgrounds in a previously developed multifeature computer-aided diagnosis (CADx) system to classify melanocytic and non-melanocytic skin lesions based on conventional digital photographic images. Methods In total, 347 conventional photographs of melanocytic and non-melanocytic skin lesions were retrospectively reviewed, and manually segmented by two groups of physicians, dermatologists and general practitioners, as well as by an automated segmentation software program, JSEG. The performance of CADx based on inputs from these two groups of physicians and that of the JSEG program was compared using feature agreement analysis. Results The estimated area under the receiver operating characteristic curve for classification of benign or malignant skin lesions based were comparable on individual segmentation by the gold standard (0.893, 95% CI 0.856 to 0.930), dermatologists (0.886, 95% CI 0.863 to 0.908), general practitioners (0.883, 95% CI 0.864 to 0.903) and JSEG (0.856, 95% CI 0.812 to 0.899). The agreement in the malignancy probability scores among the physicians was excellent (intraclass correlation coefficient: 0.91). By selecting an optimal cut-off value of malignancy probability score, the sensitivity and specificity were 80.07% and 81.47% for dermatologists and 79.90% and 80.20% for general practitioners. Conclusions This study suggests that manual segmentation by general practitioners is feasible in the described CADx system for classifying benign and malignant skin lesions. PMID:25941190

  19. The effect of CO2 and Nd:YAP lasers on CAD/CAM Ceramics: SEM, EDS and thermal studies

    PubMed Central

    Fornaini, Carlo; Rocca, Jean Paul; Muhammad, Omid H; Medioni, Etienne; Cucinotta, Annamaria; Brulat-Bouchard, Nathalie

    2016-01-01

    Background and aims: The objective of this study was to investigate the interaction of infrared laser light on Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) ceramic surfaces. Material and Methods: Sixty CAD/CAM ceramic discs were prepared and divided into two different groups: lithiumdisilicate ceramic (IPSe.maxCADs) and Zirconia ceramic (IPSe.maxZirCADs). The laser irradiation was performed on graphite and non-graphite surfaces with a Carbon Dioxide laser at 5W and 10W power in continuous mode (CW mode) and with Neodymium Yttrium Aluminum Perovskite (Nd:YAP) laser at 10W. Surface textures and compositions were examined using Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Thermal elevation was measured by thermocouple during laser irradiation. Results: The SEM observation showed a rough surface plus cracks and fissures on CO2 10W samples and melting areas in Nd:YAP samples; moreover, with CO2 5W smooth and shallow surfaces were observed. EDS analysis revealed that laser irradiation does not result in modifications of the chemical composition even if minor changes in the atomic mass percentage of the components were registered. Thermocouple showed several thermal changes during laser irradiation. Conclusion: CO2 and Nd:YAP lasers modify CAD/CAM ceramic surface without chemical composition modifications. PMID:27141152

  20. A cloud platform for remote diagnosis of breast cancer in mammography by fusion of machine and human intelligence

    NASA Astrophysics Data System (ADS)

    Jiang, Guodong; Fan, Ming; Li, Lihua

    2016-03-01

    Mammography is the gold standard for breast cancer screening, reducing mortality by about 30%. The application of a computer-aided detection (CAD) system to assist a single radiologist is important to further improve mammographic sensitivity for breast cancer detection. In this study, a design and realization of the prototype for remote diagnosis system in mammography based on cloud platform were proposed. To build this system, technologies were utilized including medical image information construction, cloud infrastructure and human-machine diagnosis model. Specifically, on one hand, web platform for remote diagnosis was established by J2EE web technology. Moreover, background design was realized through Hadoop open-source framework. On the other hand, storage system was built up with Hadoop distributed file system (HDFS) technology which enables users to easily develop and run on massive data application, and give full play to the advantages of cloud computing which is characterized by high efficiency, scalability and low cost. In addition, the CAD system was realized through MapReduce frame. The diagnosis module in this system implemented the algorithms of fusion of machine and human intelligence. Specifically, we combined results of diagnoses from doctors' experience and traditional CAD by using the man-machine intelligent fusion model based on Alpha-Integration and multi-agent algorithm. Finally, the applications on different levels of this system in the platform were also discussed. This diagnosis system will have great importance for the balanced health resource, lower medical expense and improvement of accuracy of diagnosis in basic medical institutes.

  1. Continuity of computer-aided drafting operations

    SciTech Connect

    Jacobson, L.D.

    1987-09-01

    The operating performance, operating procedures, and equipment added are discussed for the Computer Aided Drafting (CAD) operation at UNC Nuclear Industries before consolidation of operating contracts at the US Department of Energy (DOE) facilities located at the Hanford Site, near Richland, Washington.

  2. CAD system for automatic analysis of CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Hachaj, T.; Ogiela, M. R.

    2011-03-01

    In this article, authors present novel algorithms developed for the computer-assisted diagnosis (CAD) system for analysis of dynamic brain perfusion, computer tomography (CT) maps, cerebral blood flow (CBF), and cerebral blood volume (CBV). Those methods perform both quantitative analysis [detection and measurement and description with brain anatomy atlas (AA) of potential asymmetries/lesions] and qualitative analysis (semantic interpretation of visualized symptoms). The semantic interpretation (decision about type of lesion: ischemic/hemorrhagic, is the brain tissue at risk of infraction or not) of visualized symptoms is done by, so-called, cognitive inference processes allowing for reasoning on character of pathological regions based on specialist image knowledge. The whole system is implemented in.NET platform (C# programming language) and can be used on any standard PC computer with.NET framework installed.

  3. AIDS: Psychosocial Dimensions

    PubMed Central

    Stapleton, Dan

    1986-01-01

    In order to provide comprehensive care to patients who have AIDS, it is important for the family physician to understand the psychosocial elements of the disease. Homosexual men who have AIDS face particular problems, such as the disclosure of sexual orientation to family and friends. Issues discussed in this article include the reactions of the patient, family and friends to the diagnosis, the stigma of AIDS, the patient's support network, and preparations for disability and death. The facts about AIDS are discussed briefly, and the psychosocial implications of the illness for patients and their “significant others” are examined. The role of the family physician is highlighted. PMID:21267233

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

    PubMed

    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.

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

    PubMed

    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. PMID:27586486

  6. From Artisanal to CAD-CAM Blocks: State of the Art of Indirect Composites.

    PubMed

    Mainjot, A K; Dupont, N M; Oudkerk, J C; Dewael, T Y; Sadoun, M J

    2016-05-01

    Indirect composites have been undergoing an impressive evolution over the last few years. Specifically, recent developments in computer-aided design-computer-aided manufacturing (CAD-CAM) blocks have been associated with new polymerization modes, innovative microstructures, and different compositions. All these recent breakthroughs have introduced important gaps among the properties of the different materials. This critical state-of-the-art review analyzes the strengths and weaknesses of the different varieties of CAD-CAM composite materials, especially as compared with direct and artisanal indirect composites. Indeed, new polymerization modes used for CAD-CAM blocks-especially high temperature (HT) and, most of all, high temperature-high pressure (HT-HP)-are shown to significantly increase the degree of conversion in comparison with light-cured composites. Industrial processes also allow for the augmentation of the filler content and for the realization of more homogeneous structures with fewer flaws. In addition, due to their increased degree of conversion and their different monomer composition, some CAD-CAM blocks are more advantageous in terms of toxicity and monomer release. Finally, materials with a polymer-infiltrated ceramic network (PICN) microstructure exhibit higher flexural strength and a more favorable elasticity modulus than materials with a dispersed filler microstructure. Consequently, some high-performance composite CAD-CAM blocks-particularly experimental PICNs-can now rival glass-ceramics, such as lithium-disilicate glass-ceramics, for use as bonded partial restorations and crowns on natural teeth and implants. Being able to be manufactured in very low thicknesses, they offer the possibility of developing innovative minimally invasive treatment strategies, such as "no prep" treatment of worn dentition. Current issues are related to the study of bonding and wear properties of the different varieties of CAD-CAM composites. There is also a crucial

  7. Web-Based Learning in the Computer-Aided Design Curriculum.

    ERIC Educational Resources Information Center

    Sung, Wen-Tsai; Ou, S. C.

    2002-01-01

    Applies principles of constructivism and virtual reality (VR) to computer-aided design (CAD) curriculum, particularly engineering, by integrating network, VR and CAD technologies into a Web-based learning environment that expands traditional two-dimensional computer graphics into a three-dimensional real-time simulation that enhances user…

  8. Pipe Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Smithson, Buddy

    This teacher's guide contains nine units of instruction for a course on computer-assisted pipe drafting. The course covers the following topics: introduction to pipe drafting with CAD (computer-assisted design); flow diagrams; pipe and pipe components; valves; piping plans and elevations; isometrics; equipment fabrication drawings; piping design…

  9. Development of Cad System for Diffuse Disease Based on Ultrasound Elasticity Images

    NASA Astrophysics Data System (ADS)

    Yamazaki, M.; Shiina, T.; Yamakawa, M.; Takizawa, H.; Tonomura, A.; Mitake, T.

    It is well known that as hepatic cirrhosis progresses, hepatocyte fibrosis spreads and nodule increases. However, it is not easy to diagnosis its early stage by conventional B-mode image because we have to read subtle change of speckle pattern which is not sensitive to the stage of fibrosis. Ultrasonic tissue elasticity imaging can provide us novel diagnostic information based on tissue hardness. We recently developed commercial-based equipment for tissue elasticity imaging. In this work, we investigated to develop the CAD system based on elasticity image for diagnosing defused type diseases such as hepatic cirrhosis. The results of clinical data analysis indicate that the CAD system is promising as means for diagnosis of diffuse disease with simple criterion.

  10. Management of CAD/CAM information: Key to improved manufacturing productivity

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Brainin, J.

    1984-01-01

    A key element to improved industry productivity is effective management of CAD/CAM information. To stimulate advancements in this area, a joint NASA/Navy/Industry project designated Integrated Programs for Aerospace-Vehicle Design (IPAD) is underway with the goal of raising aerospace industry productivity through advancement of technology to integrate and manage information involved in the design and manufacturing process. The project complements traditional NASA/DOD research to develop aerospace design technology and the Air Force's Integrated Computer-Aided Manufacturing (ICAM) program to advance CAM technology. IPAD research is guided by an Industry Technical Advisory Board (ITAB) composed of over 100 repesentatives from aerospace and computer companies. The IPAD accomplishments to date in development of requirements and prototype software for various levels of company-wide CAD/CAM data management are summarized and plans for development of technology for management of distributed CAD/CAM data and information required to control future knowledge-based CAD/CAM systems are discussed.

  11. True Concurrent Thermal Engineering Integrating CAD Model Building with Finite Element and Finite Difference Methods

    NASA Technical Reports Server (NTRS)

    Panczak, Tim; Ring, Steve; Welch, Mark

    1999-01-01

    Thermal engineering has long been left out of the concurrent engineering environment dominated by CAD (computer aided design) and FEM (finite element method) software. Current tools attempt to force the thermal design process into an environment primarily created to support structural analysis, which results in inappropriate thermal models. As a result, many thermal engineers either build models "by hand" or use geometric user interfaces that are separate from and have little useful connection, if any, to CAD and FEM systems. This paper describes the development of a new thermal design environment called the Thermal Desktop. This system, while fully integrated into a neutral, low cost CAD system, and which utilizes both FEM and FD methods, does not compromise the needs of the thermal engineer. Rather, the features needed for concurrent thermal analysis are specifically addressed by combining traditional parametric surface based radiation and FD based conduction modeling with CAD and FEM methods. The use of flexible and familiar temperature solvers such as SINDA/FLUINT (Systems Improved Numerical Differencing Analyzer/Fluid Integrator) is retained.

  12. PC Board Layout and Electronic Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Bryson, Jimmy

    This teacher's guide contains 11 units of instruction for a course on computer electronics and computer-assisted drafting (CAD) using a personal computer (PC). The course covers the following topics: introduction to electronic drafting with CAD; CAD system and software; basic electronic theory; component identification; basic integrated circuit…

  13. CAD/CAM. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Zuleger, Robert

    This high technology training module is an advanced course on computer-assisted design/computer-assisted manufacturing (CAD/CAM) for grades 11 and 12. This unit, to be used with students in advanced drafting courses, introduces the concept of CAD/CAM. The content outline includes the following seven sections: (1) CAD/CAM software; (2) computer…

  14. Education and Training Packages for CAD/CAM.

    ERIC Educational Resources Information Center

    Wright, I. C.

    1986-01-01

    Discusses educational efforts in the fields of Computer Assisted Design and Manufacturing (CAD/CAM). Describes two educational training initiatives underway in the United Kingdom, one of which is a resource materials package for teachers of CAD/CAM at the undergraduate level, and the other a training course for managers of CAD/CAM systems. (TW)

  15. A CAD (Classroom Assessment Design) of a Computer Programming Course

    ERIC Educational Resources Information Center

    Hawi, Nazir S.

    2012-01-01

    This paper presents a CAD (classroom assessment design) of an entry-level undergraduate computer programming course "Computer Programming I". CAD has been the product of a long experience in teaching computer programming courses including teaching "Computer Programming I" 22 times. Each semester, CAD is evaluated and modified for the subsequent…

  16. Integrated computer-aided design using minicomputers

    NASA Technical Reports Server (NTRS)

    Storaasli, O. O.

    1980-01-01

    Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), a highly interactive software, has been implemented on minicomputers at the NASA Langley Research Center. CAD/CAM software integrates many formerly fragmented programs and procedures into one cohesive system; it also includes finite element modeling and analysis, and has been interfaced via a computer network to a relational data base management system and offline plotting devices on mainframe computers. The CAD/CAM software system requires interactive graphics terminals operating at a minimum of 4800 bits/sec transfer rate to a computer. The system is portable and introduces 'interactive graphics', which permits the creation and modification of models interactively. The CAD/CAM system has already produced designs for a large area space platform, a national transonic facility fan blade, and a laminar flow control wind tunnel model. Besides the design/drafting element analysis capability, CAD/CAM provides options to produce an automatic program tooling code to drive a numerically controlled (N/C) machine. Reductions in time for design, engineering, drawing, finite element modeling, and N/C machining will benefit productivity through reduced costs, fewer errors, and a wider range of configuration.

  17. 3D-WOVEN FIBER-REINFORCED COMPOSITE FOR CAD/CAM DENTAL APPLICATION

    PubMed Central

    Petersen, Richard; Liu, Perng-Ru

    2016-01-01

    Three-dimensional (3D)-woven noncrimp fiber-reinforced composite (FRC) was tested for mechanical properties in the two principal directions of the main XY plane and compared to different Computer-Aided-Design/Computer-Aided-Machining (CAD/CAM) Dental Materials. The Dental Materials included ceramic with Vitablock Mark II®, ProCAD®, InCeram® Spinel, InCeram® Alumina and InCeram® Zirconia in addition to a resin-based 3M Corp. Paradigm® particulate-filled composite. Alternate material controls included Coors 300 Alumina Ceramic and a tungsten carbide 22% cobalt cermet. The 3D-woven FRC was vacuum assisted resin transfer molding processed as a one-depth-thickness ~19-mm preform with a vinyl-ester resin and cut into blocks similar to the commercial CAD/CAM Dental Materials. Mechanical test samples prepared for a flexural three-point span length of 10.0 mm were sectioned for minimum-depth cuts to compare machinability and fracture resistance between groups. 3D-woven FRC improved mechanical properties with significant statistical differences over all CAD/CAM Dental Materials and Coors Alumina Ceramic for flexural strength (p<0.001), resilience (p<0.05), work of fracture (p<0.001), strain energy release (p<0.05), critical stress intensity factor (p<0.001) and strain (p<0.001). PMID:27642198

  18. ProperCAD: A portable object-oriented parallel environment for VLSI CAD

    NASA Technical Reports Server (NTRS)

    Ramkumar, Balkrishna; Banerjee, Prithviraj

    1993-01-01

    Most parallel algorithms for VLSI CAD proposed to date have one important drawback: they work efficiently only on machines that they were designed for. As a result, algorithms designed to date are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. A new project under way to address this problem is described. A Portable object-oriented parallel environment for CAD algorithms (ProperCAD) is being developed. The objectives of this research are (1) to develop new parallel algorithms that run in a portable object-oriented environment (CAD algorithms using a general purpose platform for portable parallel programming called CARM is being developed and a C++ environment that is truly object-oriented and specialized for CAD applications is also being developed); and (2) to design the parallel algorithms around a good sequential algorithm with a well-defined parallel-sequential interface (permitting the parallel algorithm to benefit from future developments in sequential algorithms). One CAD application that has been implemented as part of the ProperCAD project, flat VLSI circuit extraction, is described. The algorithm, its implementation, and its performance on a range of parallel machines are discussed in detail. It currently runs on an Encore Multimax, a Sequent Symmetry, Intel iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube, and a network of Sun Sparc workstations. Performance data for other applications that were developed are provided: namely test pattern generation for sequential circuits, parallel logic synthesis, and standard cell placement.

  19. SU-E-I-30: Image Analysis in Ultrasonography for Diagnosis of Sjoegren's Syndrome Using Dual-Tree Complex Wavelet Transform

    SciTech Connect

    Matsui, T; Ohki, M; Nakamura, T; Takagi, Y

    2014-06-01

    Purpose: Sjoegren's syndrome (SS) is an autoimmune disease invading mainly salivary and lacrimal glands. Ultrasonography is used for an initial and non-invasive examination of this disease. However, the ultrasonography diagnosis tends to lack in objectivity and depends on the operator's skills. The purpose of this study is to propose a computer-aided diagnosis (CAD) system for SS based on a dual-tree complex wavelet transform (DT-CWT) and machine learning. Methods: The subjects of this study were 174 patients suspected of having SS at Nagasaki University Hospital and examined with ultrasonography of the parotid glands. Out of these patients, 77 patients were diagnosed with SS by sialography. A region of interest (ROI) of 128 × 128 pixels was set within the parotid gland that was indicated by a dental radiologist. The DT-CWT was applied to the images in the ROI and every image was decomposed into 72 sub-images of the real and imaginary components in six different resolution levels and six orientations. The statistical features of the sub-image were calculated and used as data input for the support vector machine (SVM) classifier for the detection of SS. A ten-fold cross-validation was employed to verify the Resultof SVM. The accuracy of diagnosis was compared by a CAD system with a human observer performance. Results: The sensitivity, specificity, and accuracy in the detection of SS were 95%, 86%, and 91% through our CAD system respectively, while those by a human observer were 84%, 81%, and 83% respectively. Conclusion: The proposed computer-aided diagnosis system for Sjoegren's syndrome in ultrasonography based on dual-tree complex wavelet transform had a better performance than a human observer.

  20. Cost reduction advantages of CAD/CAM

    NASA Astrophysics Data System (ADS)

    Parsons, G. T.

    1983-05-01

    Features of the CAD/CAM system implemented at the General Dynamics Convair division are summarized. CAD/CAM was initiated in 1976 to enhance engineering, manufacturing and quality assurance and thereby the company's competitive bidding position. Numerical models are substituted for hardware models wherever possible and numerical criteria are defined in design for guiding computer-controlled parts manufacturing machines. The system comprises multiple terminals, a data base, digitizer, printers, disk and tape drives, and graphics displays. The applications include the design and manufacture of parts and components for avionics, structures, scientific investigations, and aircraft structural components. Interfaces with other computers allow structural analyses by finite element codes. Although time savings have not been gained compared to manual drafting, components of greater complexity than could have been designed by hand have been designed and manufactured.

  1. AutoCAD-To-GIFTS Translator Program

    NASA Technical Reports Server (NTRS)

    Jones, Andrew

    1989-01-01

    AutoCAD-to-GIFTS translator program, ACTOG, developed to facilitate quick generation of small finite-element models using CASA/GIFTS finite-element modeling program. Reads geometric data of drawing from Data Exchange File (DXF) used in AutoCAD and other PC-based drafting programs. Geometric entities recognized by ACTOG include points, lines, arcs, solids, three-dimensional lines, and three-dimensional faces. From this information, ACTOG creates GIFTS SRC file, which then reads into GIFTS preprocessor BULKM or modified and reads into EDITM to create finite-element model. SRC file used as is or edited for any number of uses. Written in Microsoft Quick-Basic (Version 2.0).

  2. DFE workbench: a CAD integrated DFE tool

    NASA Astrophysics Data System (ADS)

    Man, Elena; Diez-Campo, Juan E.; Roche, Thomas

    2002-02-01

    Because of the emergent legislation (e.g. WEEE and EOLV), environmental standards (e.g. ISO 14000) and a shift in consumer opinion toward environmentally superior products, there is an increased need for CAD integrated Design for Environment tools to assist the designer in the development of environmentally superior products (ESP). Implementing Design for the Environment practices is an extremely effective strategy, as it is widely believed that 95% of development costs are determined at this stage. Many methodologies and tools have been developed to perform environmental analysis; however, many existing methodologies are inadequately integrated in the design process. This paper addresses these problems and presents a CAD integrated DFE tool that has been under development in the authors' institutes for the last number of years.

  3. IPAD 2: Advances in Distributed Data Base Management for CAD/CAM

    NASA Technical Reports Server (NTRS)

    Bostic, S. W. (Compiler)

    1984-01-01

    The Integrated Programs for Aerospace-Vehicle Design (IPAD) Project objective is to improve engineering productivity through better use of computer-aided design and manufacturing (CAD/CAM) technology. The focus is on development of technology and associated software for integrated company-wide management of engineering information. The objectives of this conference are as follows: to provide a greater awareness of the critical need by U.S. industry for advancements in distributed CAD/CAM data management capability; to present industry experiences and current and planned research in distributed data base management; and to summarize IPAD data management contributions and their impact on U.S. industry and computer hardware and software vendors.

  4. Clinical and Laboratory Steps for Fabricating a Complete-Arch Fixed Prosthesis Using CAD/CAM.

    PubMed

    Keerthi, Senthil; Proussaefs, Periklis; Lozada, Jaime

    2015-01-01

    The fabrication of a full-arch maxillary prosthesis has been associated with several prosthetic complications and difficulties. Even though it has been reported that phonetics, esthetics, and proper lip support are difficult to achieve, there is a scarcity in the literature regarding the clinical and laboratory procedures necessary to minimize these complications. This article provides clinical and laboratory steps that may enable the clinician to achieve more predictable restorative results when using computer-aided design/computer-assisted manufacture (CAD/CAM) to fabricate a full-arch maxillary implant-supported prosthesis. The technique presented here describes the use of an implant-retained diagnostic wax-up that is subsequently duplicated to an interim polymethylmethacrylate prosthesis using CAD/CAM before fabricating the definitive restoration.

  5. Multiple platform application of 3D CAD PIC simulations in pulsed power

    SciTech Connect

    Peratt, A.L.; Mostrom, M.A.

    1995-12-31

    With the availability of 80--125 MHz microprocessors, the methodology developed for the simulation of problems in pulsed power and plasma physics on modern day supercomputers is now amenable to application on a wide range of platforms including laptops and workstations. While execution speeds with these processors do not match those of large scale computing machines, resources such as computer-aided-design (CAD) and graphical analysis codes are available to automate simulation setup and process data. This paper reports on the adaptation of IVORY, a three-dimensional, fully-electromagnetic, particle-in-cell simulation code, to this platform independent CAD environment. The primary purpose of this talk is to demonstrate how rapidly a pulsed power/plasma problem can be scoped out by an experimenter on a dedicated workstation. Demonstrations include a magnetically insulated transmission line, power flow in a graded insulator stack, a relativistic klystron oscillator, and the dynamics of a coaxial thruster for space applications.

  6. Development of personalized annuloplasty rings: combination of CT images and CAD-CAM tools.

    PubMed

    Díaz Lantada, Andrés; Valle-Fernández, Raquel Del; Morgado, Pilar Lafont; Muñoz-García, Julio; Muñoz Sanz, José Luis; Munoz-Guijosa, Juan Manuel; Otero, Javier Echávarri

    2010-02-01

    Although the use of personalized annuloplasty rings manufactured for each patient according to the size and morphology of their valve complex could be beneficial for the treatment of mitral insufficiency, this possibility has been limited for reasons of time-lines and costs as well as for design and manufacturing difficulties, as has been the case with other personalized implant and prosthetic developments. However, the present quality of medical image capture equipment together with the benefits to be had from computer-aided design and manufacturing technologies (CAD-CAM) and the capabilities furnished by rapid prototyping technologies, present new opportunities for a personalized response to the development of implants and prostheses, the social impact of which could turn out to be highly positive. This paper sets out a personalized development of an annuloplasty ring based on the combined use of information from medical imaging, from CAD-CAM design programs and prototype manufacture using rapid prototyping technologies.

  7. Development of personalized annuloplasty rings: combination of CT images and CAD-CAM tools.

    PubMed

    Díaz Lantada, Andrés; Valle-Fernández, Raquel Del; Morgado, Pilar Lafont; Muñoz-García, Julio; Muñoz Sanz, José Luis; Munoz-Guijosa, Juan Manuel; Otero, Javier Echávarri

    2010-02-01

    Although the use of personalized annuloplasty rings manufactured for each patient according to the size and morphology of their valve complex could be beneficial for the treatment of mitral insufficiency, this possibility has been limited for reasons of time-lines and costs as well as for design and manufacturing difficulties, as has been the case with other personalized implant and prosthetic developments. However, the present quality of medical image capture equipment together with the benefits to be had from computer-aided design and manufacturing technologies (CAD-CAM) and the capabilities furnished by rapid prototyping technologies, present new opportunities for a personalized response to the development of implants and prostheses, the social impact of which could turn out to be highly positive. This paper sets out a personalized development of an annuloplasty ring based on the combined use of information from medical imaging, from CAD-CAM design programs and prototype manufacture using rapid prototyping technologies. PMID:19826955

  8. Low-Dose CT Screening for Lung Cancer: Computer-aided Detection of Missed Lung Cancers.

    PubMed

    Liang, Mingzhu; Tang, Wei; Xu, Dong Ming; Jirapatnakul, Artit C; Reeves, Anthony P; Henschke, Claudia I; Yankelevitz, David

    2016-10-01

    Purpose To update information regarding the usefulness of computer-aided detection (CAD) systems with a focus on the most critical category, that of missed cancers at earlier imaging, for cancers that manifest as a solid nodule. Materials and Methods By using a HIPAA-compliant institutional review board-approved protocol where informed consent was obtained, 50 lung cancers that manifested as a solid nodule on computed tomographic (CT) scans in annual rounds of screening (time 1) were retrospectively identified that could, in retrospect, be identified on the previous CT scans (time 0). Four CAD systems were compared, which were referred to as CAD 1, CAD 2, CAD 3, and CAD 4. The total number of accepted CAD-system-detected nodules at time 0 was determined by consensus of two radiologists and the number of CAD-system-detected nodules that were rejected by the radiologists was also documented. Results At time 0 when all the cancers had been missed, CAD system detection rates for the cancers were 56%, 70%, 68%, and 60% (κ = 0.45) for CAD systems 1, 2, 3, and 4, respectively. At time 1, the rates were 74%, 82%, 82%, and 78% (κ = 0.32), respectively. The average diameter of the 50 cancers at time 0 and time 1 was 4.8 mm and 11.4 mm, respectively. The number of CAD-system-detected nodules that were rejected per CT scan for CAD systems 1-4 at time 0 was 7.4, 1.7, 0.6, and 4.5 respectively. Conclusion CAD systems detected up to 70% of lung cancers that were not detected by the radiologist but failed to detect about 20% of the lung cancers when they were identified by the radiologist, which suggests that CAD may be useful in the role of second reader. (©) RSNA, 2016.

  9. CAD Integration : new optical design possibilities

    NASA Astrophysics Data System (ADS)

    Haumonte, Jean-Baptiste; Venturino, Jean-Claude

    2005-09-01

    The development of optical design and analysis tools in a CAD software can help to optimise the design, size and performance of tomorrow's consumer products. While optics was still held back by software limitations, CAD programs were moving forward in leaps and bounds, improving manufacturing technologies and making it possible to design and produce highly innovative and sophisticated products. The problem was that in the past, 'traditional' optical design programs were only able to simulate spherical and aspherical lenses, meaning that the optical designers were limited to designing systems which were a series of imperfect lenses, each one correcting the last. That is why OPTIS has created the first optical design program to be fully integrated into a CAD program. The technology is available from OPTIS in an integrated SOLIDWORKS or CATIA V5 version. Users of this software can reduce the number of lenses needed in a system. Designers will now have access to complex surfaces such as NURBS meaning they will now be able to define free shape progressive lenses and even improve on optical performances using fewer lenses. This revolutionary technology will allow mechanical designers to work on optical systems and to share information with optical designers for the first time. Previously not possible in a CAD program you may now determine all the optical performances of any optical system, providing first order and third order performances, sequential and non-sequential ray-tracing, wavefront surfaces, point spread function, MTF, spot-diagram, using real optical surfaces and guaranteeing the mechanical precision necessary for an optical system.

  10. Digital breast tomosynthesis: application of 2D digital mammography CAD to detection of microcalcification clusters on planar projection image

    NASA Astrophysics Data System (ADS)

    Samala, Ravi K.; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir; Wei, Jun; Helvie, Mark

    2015-03-01

    Computer-aided detection (CAD) has the potential to aid radiologists in detection of microcalcification clusters (MCs). CAD for digital breast tomosynthesis (DBT) can be developed by using the reconstructed volume, the projection views or other derivatives as input. We have developed a novel method of generating a single planar projection (PPJ) image from a regularized DBT volume to emphasize the high contrast objects such as microcalcifications while removing the anatomical background and noise. In this work, we adapted a CAD system developed for digital mammography (CADDM) to the PPJ image and compared its performance with our CAD system developed for DBT volumes (CADDBT) in the same set of cases. For microcalcification detection in the PPJ image using the CADDM system, the background removal preprocessing step designed for DM was not needed. The other methods and processing steps in the CADDM system were kept without modification while the parameters were optimized with a training set. The linear discriminant analysis classifier using cluster based features was retrained to generate a discriminant score to be used as decision variable. For view-based FROC analysis, at 80% sensitivity, an FP rate of 1.95/volume and 1.54/image were achieved, respectively, for CADDBT and CADDM in an independent test set. At a threshold of 1.2 FPs per image or per DBT volume, the nonparametric analysis of the area under the FROC curve shows that the optimized CADDM for PPJ is significantly better than CADDBT. However, the performance of CADDM drops at higher sensitivity or FP rate, resulting in similar overall performance between the two CAD systems. The higher sensitivity of the CADDM in the low FP rate region and vice versa for the CADDBT indicate that a joint CAD system combining detection in the DBT volume and the PPJ image has the potential to increase the sensitivity and reduce the FP rate.

  11. Predictors of Late HIV Diagnosis among Adult People Living with HIV/AIDS Who Undertake an Initial CD4 T Cell Evaluation, Northern Ethiopia: A Case-Control Study

    PubMed Central

    Beyene, Melkamu Bedimo; Beyene, Habtamu Bedimo

    2015-01-01

    Introduction Early HIV testing and timely initiation of ART is critical for the improved quality of life of PLWHIV. Having identified a higher rates of Late HIV diagnosis, this study was aimed to determine Determinants of late diagnosis of HIV among adult HIV patients in Bahir Dar, Northern Ethiopia. Methods A case control study was conducted between January 2010 to December 2011 at Bahir Dar Felege Hiwot Referral Hospital. The study subjects consisted of 267 cases and 267 controls. Cases were adult people living with HIV/AIDS whose initial CD4 T cell count was < 200/μl of blood. Controls were those with a CD4 T cell count of greater than 200/ μl. Trained staff nurses were involved in data collection using a semi-structured questionnaire. Data was entered and analyzed using SPSS version 20. Descriptive statistics and Binary logistic regression were performed. Results Subjects who hold a certificate and above (AOR = 0.26; 95% CI = 0.13. 0.54), being initiated by friends, families and other socials to undertake HIV testing (AOR = 0.65; 95% CI = 0.29, 1.48), who reported a medium and high knowledge score about HIV/AIDS and who undertake HIV testing while visiting a clinic for ANC (AOR = 0.40; 95% CI = 0.19, 0.83) were less likely to be diagnosed late. Subjects who undertake HIV testing due to providers’ initiation (AOR = 1.70; 95%CI = 1.08, 2.68), who reported a medium internalized stigma (AOR = 4.94; 95% CI = 3.13, 7.80) and who reported a high internalized stigma score towards HIV/AIDS (AOR = 16.64; 95% CI = 8.29, 33.4) had a high odds of being diagnosed late compared to their counterparts. Conclusion Internalized stigma, low knowledge level about HIV/AIDS, not to have attended formal education and failure to undertake HIV testing by own initiation were significant determinant factors associated with Late HIV diagnosis. Education about HIV/AIDS, promotion of general education, and encouraging people to motivate their social mates to undertake HIV testing are

  12. Ergonomics Perspective in Agricultural Research: A User-Centred Approach Using CAD and Digital Human Modeling (DHM) Technologies

    NASA Astrophysics Data System (ADS)

    Patel, Thaneswer; Sanjog, J.; Karmakar, Sougata

    2016-09-01

    Computer-aided Design (CAD) and Digital Human Modeling (DHM) (specialized CAD software for virtual human representation) technologies endow unique opportunities to incorporate human factors pro-actively in design development. Challenges of enhancing agricultural productivity through improvement of agricultural tools/machineries and better human-machine compatibility can be ensured by adoption of these modern technologies. Objectives of present work are to provide the detailed scenario of CAD and DHM applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator's workplace. Extensive literature review has been conducted for systematic segregation and representation of available information towards drawing inferences. Although applications of various CAD software have momentum in agricultural research particularly for design and manufacturing of agricultural equipment/machinery, use of DHM is still at its infancy in this sector. Current review discusses about reasons of less adoption of these technologies in agricultural sector and steps to be taken for their wide adoption. It also suggests possible future research directions to come up with better ergonomic design strategies for improvement of agricultural equipment/machines and workstations through application of CAD and DHM.

  13. Ergonomics Perspective in Agricultural Research: A User-Centred Approach Using CAD and Digital Human Modeling (DHM) Technologies

    NASA Astrophysics Data System (ADS)

    Patel, Thaneswer; Sanjog, J.; Karmakar, Sougata

    2016-06-01

    Computer-aided Design (CAD) and Digital Human Modeling (DHM) (specialized CAD software for virtual human representation) technologies endow unique opportunities to incorporate human factors pro-actively in design development. Challenges of enhancing agricultural productivity through improvement of agricultural tools/machineries and better human-machine compatibility can be ensured by adoption of these modern technologies. Objectives of present work are to provide the detailed scenario of CAD and DHM applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator's workplace. Extensive literature review has been conducted for systematic segregation and representation of available information towards drawing inferences. Although applications of various CAD software have momentum in agricultural research particularly for design and manufacturing of agricultural equipment/machinery, use of DHM is still at its infancy in this sector. Current review discusses about reasons of less adoption of these technologies in agricultural sector and steps to be taken for their wide adoption. It also suggests possible future research directions to come up with better ergonomic design strategies for improvement of agricultural equipment/machines and workstations through application of CAD and DHM.

  14. CT colonography with computer-aided detection: recognizing the causes of false-positive reader results.

    PubMed

    Trilisky, Igor; Wroblewski, Kristen; Vannier, Michael W; Horne, John M; Dachman, Abraham H

    2014-01-01

    Computed tomography (CT) colonography is a screening modality used to detect colonic polyps before they progress to colorectal cancer. Computer-aided detection (CAD) is designed to decrease errors of detection by finding and displaying polyp candidates for evaluation by the reader. CT colonography CAD false-positive results are common and have numerous causes. The relative frequency of CAD false-positive results and their effect on reader performance on the basis of a 19-reader, 100-case trial shows that the vast majority of CAD false-positive results were dismissed by readers. Many CAD false-positive results are easily disregarded, including those that result from coarse mucosa, reconstruction, peristalsis, motion, streak artifacts, diverticulum, rectal tubes, and lipomas. CAD false-positive results caused by haustral folds, extracolonic candidates, diminutive lesions (<6 mm), anal papillae, internal hemorrhoids, varices, extrinsic compression, and flexural pseudotumors are almost always recognized and disregarded. The ileocecal valve and tagged stool are common sources of CAD false-positive results associated with reader false-positive results. Nondismissable CAD soft-tissue polyp candidates larger than 6 mm are another common cause of reader false-positive results that may lead to further evaluation with follow-up CT colonography or optical colonoscopy. Strategies for correctly evaluating CAD polyp candidates are important to avoid pitfalls from common sources of CAD false-positive results.

  15. Advanced layout parameter extraction and detailed timing simulation of GaAs gate arrays in MagiCAD

    NASA Astrophysics Data System (ADS)

    Buchs, Kevin J.; Rowlands, David O.; Prentice, Jeffrey A.; Gilbert, Barry K.

    1990-10-01

    This paper discusses the features and function of three specific computer aided design tools contained in the Mayo Graphical Integrated Computer Aided Design (MagiCAD) system a complete electronic CAD software package optimized for the design and layout of semicustom (i. e. gate array) Gallium Arsenide (GaAs) integrated circuits. The first design tool the Layout Extractor processes data from placed and routed gate arrays. The Extractor verifies that the layout represents the original logic design and calculates the parasitic capacitance of the individual wiring segments in the logic nets after they have been routed. The capacitance information as calculated by the Layout Extractor is significant in GaAs work since the delay in signals traveling through the routing is often much greater than the delay of the signals traveling through the gates themselves. Once the capacitance data has been processed by the Layout Extractor it becomes available to the second CAD tool discussed here the MagiCAD timing simulation program Sting. Sting a digital event-driven simulator depends on user generation of C language-like behavioral models for all root nodes to be simulated. Through the use of delays calculated by the Extractor from the actual routing and input pin capacitances Sting assures that the entire chip design will operate correctly at the intended clock rate. The third design tool is a set of programs allowing simulation of the electromagnetic behavior of integrated circuit packages circuit

  16. HIV / AIDS

    MedlinePlus

    ... Marketing Share this: Main Content Area Understanding HIV/AIDS AIDS was first reported in the United States in ... and has since become a major worldwide epidemic. AIDS is caused by the human immunodeficiency virus, or ...

  17. Fault diagnosis

    NASA Technical Reports Server (NTRS)

    Abbott, Kathy

    1990-01-01

    The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to

  18. Computer Aided Drafting Packages for Secondary Education. Edition 1. Apple II and Macintosh. A MicroSIFT Quarterly Report.

    ERIC Educational Resources Information Center

    Pollard, Jim

    This report reviews software packages for Apple Macintosh and Apple II computers available to secondary schools to teach computer-aided drafting (CAD). Products for the report were gathered through reviews of CAD periodicals, computers in education periodicals, advertisements, and teacher recommendations. The first section lists the primary…

  19. Computer Aided Drafting Packages for Secondary Education. Edition 2. PC DOS Compatible Programs. A MicroSIFT Quarterly Report.

    ERIC Educational Resources Information Center

    Pollard, Jim

    This report reviews eight IBM-compatible software packages that are available to secondary schools to teach computer-aided drafting (CAD). Software packages to be considered were selected following reviews of CAD periodicals, computers in education periodicals, advertisements, and recommendations of teachers. The packages were then rated by…

  20. Developmental tendency of hearing aid semi-auto-manufacturing

    NASA Astrophysics Data System (ADS)

    Jarng, Soon Suck; Lee, Yanbo

    2009-12-01

    What's the developmental tendency of the hearing aid manufacturing in the future? The answer is a rapid production or/and CAD/CAM technology. The new technology is quite different from the conventional manufacturing method. This article shows the differences between the 2 types of approach in detail, and analyzes these differences. The authors figure out where and how to cut an ear shell impression that will give help to the hearing aid manufacturing process, and make the CAD/CAM method to fit for the Asians' ears.

  1. Model-Based Engineering and Manufacturing CAD/CAM Benchmark

    SciTech Connect

    Domm, T.D.; Underwood, R.S.

    1999-04-26

    The Benehmark Project was created from a desire to identify best practices and improve the overall efficiency and performance of the Y-12 Plant's systems and personnel supprting the manufacturing mission. The mission of the benchmark team was to search out industry leaders in manufacturing and evaluate lheir engineering practices and processes to determine direction and focus fm Y-12 modmizadon efforts. The companies visited included several large established companies and anew, small, high-tech machining firm. As a result of this efforL changes are recommended that will enable Y-12 to become a more responsive cost-effective manufacturing facility capable of suppordng the needs of the Nuclear Weapons Complex (NW@) and Work Fw Others into the 21' century. The benchmark team identified key areas of interest, both focused and gencml. The focus arm included Human Resources, Information Management, Manufacturing Software Tools, and Standarda/ Policies and Practices. Areas of general interest included Inhstructure, Computer Platforms and Networking, and Organizational Structure. The method for obtaining the desired information in these areas centered on the creation of a benchmark questionnaire. The questionnaire was used throughout each of the visits as the basis for information gathering. The results of this benchmark showed that all companies are moving in the direction of model-based engineering and manufacturing. There was evidence that many companies are trying to grasp how to manage current and legacy data. In terms of engineering design software tools, the companies contacted were using both 3-D solid modeling and surfaced Wire-frame models. The manufacturing computer tools were varie4 with most companies using more than one software product to generate machining data and none currently performing model-based manufacturing (MBM) ftom a common medel. The majority of companies were closer to identifying or using a single computer-aided design (CAD) system than a

  2. Direct composite resin layering techniques for creating lifelike CAD/CAM-fabricated composite resin veneers and crowns.

    PubMed

    LeSage, Brian

    2014-07-01

    Direct composite resin layering techniques preserve sound tooth structure and improve function and esthetics. However, intraoral placement techniques present challenges involving isolation, contamination, individual patient characteristics, and the predictability of restorative outcomes. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations enable dentists to better handle these variables and provide durable restorations in an efficient and timely manner; however, milled restorations may appear monochromatic and lack proper esthetic characteristics. For these reasons, an uncomplicated composite resin layering restoration technique can be used to combine the benefits of minimally invasive direct restorations and the ease and precision of indirect CAD/CAM restorations. Because most dentists are familiar with and skilled at composite resin layering, the use of such a technique can provide predictable and highly esthetic results. This article describes the layered composite resin restoration technique.

  3. Direct composite resin layering techniques for creating lifelike CAD/CAM-fabricated composite resin veneers and crowns.

    PubMed

    LeSage, Brian

    2014-07-01

    Direct composite resin layering techniques preserve sound tooth structure and improve function and esthetics. However, intraoral placement techniques present challenges involving isolation, contamination, individual patient characteristics, and the predictability of restorative outcomes. Computer-aided design and computer-aided manufacturing (CAD/CAM) restorations enable dentists to better handle these variables and provide durable restorations in an efficient and timely manner; however, milled restorations may appear monochromatic and lack proper esthetic characteristics. For these reasons, an uncomplicated composite resin layering restoration technique can be used to combine the benefits of minimally invasive direct restorations and the ease and precision of indirect CAD/CAM restorations. Because most dentists are familiar with and skilled at composite resin layering, the use of such a technique can provide predictable and highly esthetic results. This article describes the layered composite resin restoration technique. PMID:24680167

  4. Validation of an enzyme-linked immunosorbent assay that detects Histoplasma capsulatum antigenuria in Colombian patients with AIDS for diagnosis and follow-up during therapy.

    PubMed

    Caceres, Diego H; Scheel, Christina M; Tobón, Angela M; Ahlquist Cleveland, Angela; Restrepo, Angela; Brandt, Mary E; Chiller, Tom; Gómez, Beatriz L

    2014-09-01

    We validated an antigen capture enzyme-linked immunosorbent assay (ELISA) in Colombian persons with AIDS and proven histoplasmosis and evaluated the correlation between antigenuria and clinical improvement during follow-up. The sensitivity of the Histoplasma capsulatum ELISA was 86%, and the overall specificity was 94%. The antigen test successfully monitored the response to therapy.

  5. Recommendations for research design and reporting in computer-assisted diagnosis to facilitate meta-analysis.

    PubMed

    Eadie, Leila H; Taylor, Paul; Gibson, Adam P

    2012-04-01

    Computer-assisted diagnosis (CAD) describes a diverse, heterogeneous range of applications rather than a single entity. The aims and functions of CAD systems vary considerably and comparing studies and systems is challenging due to methodological and design differences. In addition, poor study quality and reporting can reduce the value of some publications. Meta-analyses of CAD are therefore difficult and may not provide reliable conclusions. Aiming to determine the major sources of heterogeneity and thereby what CAD researchers could change to allow this sort of assessment, this study reviews a sample of 147 papers concerning CAD used with imaging for cancer diagnosis. It discusses sources of variability, including the goal of the CAD system, learning methodology, study population, design, outcome measures, inclusion of radiologists, and study quality. Based upon this evidence, recommendations are made to help researchers optimize the quality and comparability of their trial design and reporting.

  6. Joint feature selection and classification using a Bayesian neural network with automatic relevance determination priors: potential use in CAD of medical imaging

    NASA Astrophysics Data System (ADS)

    Chen, Weijie; Zur, Richard M.; Giger, Maryellen L.

    2007-03-01

    Bayesian neural network (BNN) with automatic relevance determination (ARD) priors has the ability to assess the relevance of each input feature during network training. Our purpose is to investigate the potential use of BNN-with-ARD-priors for joint feature selection and classification in computer-aided diagnosis (CAD) of medical imaging. With ARD priors, each group of weights that connect an input feature to the hidden units is associated with a hyperparameter controlling the magnitudes of the weights. The hyperparameters and the weights are updated simultaneously during neural network training. A smaller hyperparameter will likely result in larger weight values and the corresponding feature will likely be more relevant to the output, and thus, to the classification task. For our study, a multivariate normal feature space is designed to include one feature with high classification performance in terms of both ideal observer and linear observer, two features with high ideal observer performance but low linear observer performance and 7 useless features. An exclusive-OR (XOR) feature space is designed to include 2 XOR features and 8 useless features. Our simulation results show that the ARD-BNN approach has the ability to select the optimal subset of features on the designed nonlinear feature spaces on which the linear approach fails. ARD-BNN has the ability to recognize features that have high ideal observer performance. Stepwise linear discriminant analysis (SWLDA) has the ability to select features that have high linear observer performance but fails to select features that have high ideal observer performance and low linear observer performance. The cross-validation results on clinical breast MRI data show that ARD-BNN yields statistically significant better performance than does the SWLDA-LDA approach. We believe that ARD-BNN is a promising method for pattern recognition in computer-aided diagnosis of medical imaging.

  7. Coupling Photon Monte Carlo Simulation and CAD Software. Application to X-ray Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tabary, J.; Glière, A.

    A Monte Carlo radiation transport simulation program, EGS Nova, and a Computer Aided Design software, BRL-CAD, have been coupled within the framework of Sindbad, a Nondestructive Evaluation (NDE) simulation system. In its current status, the program is very valuable in a NDE laboratory context, as it helps simulate the images due to the uncollided and scattered photon fluxes in a single NDE software environment, without having to switch to a Monte Carlo code parameters set. Numerical validations show a good agreement with EGS4 computed and published data. As the program's major drawback is the execution time, computational efficiency improvements are foreseen.

  8. Management of CAD/CAM information: Key to improved manufacturing productivity

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Brainin, J.

    1984-01-01

    A key element to improved industry productivity is effective management of CAD/CAM information. To stimulate advancements in this area, a joint NASA/Navy/industry project designated Intergrated Programs for Aerospace-Vehicle Design (IPAD) is underway with the goal of raising aerospace industry productivity through advancement of technology to integrate and manage information involved in the design and manufacturing process. The project complements traditional NASA/DOD research to develop aerospace design technology and the Air Force's Integrated Computer-Aided Manufacturing (ICAM) program to advance CAM technology. IPAD research is guided by an Industry Technical Advisory Board (ITAB) composed of over 100 representatives from aerospace and computer companies.

  9. Additive CAD/CAM process for dental prostheses.

    PubMed

    Silva, Nelson R F A; Witek, Lukasz; Coelho, Paulo G; Thompson, Van P; Rekow, Elizabeth D; Smay, Jim

    2011-02-01

    This article describes the evolution of a computer-aided design/computer-aided manufacturing (CAD/CAM) process where ceramic paste is deposited in a layer-by-layer sequence using a computer numerical control machine to build up core and fixed partial denture (FPD) structures (robocasting). Al(2)O(3) (alumina) or ZrO(2) (Y-TZP) are blended into a 0.8% aqueous solution of ammonium polyacrylate in a ratio of approximately 1:1 solid:liquid. A viscosifying agent, hydroxypropyl methylcellulose, is added to a concentration of 1% in the liquid phase, and then a counter polyelectrolyte is added to gel the slurry. There are two methods for robocasting crown structures (cores or FPD framework). One is for the core to be printed using zirconia ink without support materials, in which the stereolithography (STL) file is inverted (occlusal surface resting on a flat substrate) and built. The second method uses a fugitive material composed of carbon black codeposited with the ceramic material. During the sintering process, the carbon black is removed. There are two key challenges to successful printing of ceramic crowns by the robocasting technique. First is the development of suitable materials for printing, and second is the design of printing patterns for assembly of the complex geometry required for a dental restoration. Robocasting has room for improvement. Current development involves enhancing the automation of nozzle alignment for accurate support material deposition and better fidelity of the occlusal surface. An accompanying effort involves calculation of optimal support structures to yield the best geometric results and minimal material usage.

  10. Model-Based Engineering and Manufacturing CAD/CAM Benchmark.

    SciTech Connect

    Domm, T.C.; Underwood, R.S.

    1999-10-13

    The Benchmark Project was created from a desire to identify best practices and improve the overall efficiency and performance of the Y-12 Plant's systems and personnel supporting the manufacturing mission. The mission of the benchmark team was to search out industry leaders in manufacturing and evaluate their engineering practices and processes to determine direction and focus for Y-12 modernization efforts. The companies visited included several large established companies and a new, small, high-tech machining firm. As a result of this effort, changes are recommended that will enable Y-12 to become a more modern, responsive, cost-effective manufacturing facility capable of supporting the needs of the Nuclear Weapons Complex (NWC) into the 21st century. The benchmark team identified key areas of interest, both focused and general. The focus areas included Human Resources, Information Management, Manufacturing Software Tools, and Standards/Policies and Practices. Areas of general interest included Infrastructure, Computer Platforms and Networking, and Organizational Structure. The results of this benchmark showed that all companies are moving in the direction of model-based engineering and manufacturing. There was evidence that many companies are trying to grasp how to manage current and legacy data. In terms of engineering design software tools, the companies contacted were somewhere between 3-D solid modeling and surfaced wire-frame models. The manufacturing computer tools were varied, with most companies using more than one software product to generate machining data and none currently performing model-based manufacturing (MBM) from a common model. The majority of companies were closer to identifying or using a single computer-aided design (CAD) system than a single computer-aided manufacturing (CAM) system. The Internet was a technology that all companies were looking to either transport information more easily throughout the corporation or as a conduit for

  11. Costs incurred by applying computer-aided design/computer-aided manufacturing techniques for the reconstruction of maxillofacial defects.

    PubMed

    Rustemeyer, Jan; Melenberg, Alex; Sari-Rieger, Aynur

    2014-12-01

    This study aims to evaluate the additional costs incurred by using a computer-aided design/computer-aided manufacturing (CAD/CAM) technique for reconstructing maxillofacial defects by analyzing typical cases. The medical charts of 11 consecutive patients who were subjected to the CAD/CAM technique were considered, and invoices from the companies providing the CAD/CAM devices were reviewed for every case. The number of devices used was significantly correlated with cost (r = 0.880; p < 0.001). Significant differences in mean costs were found between cases in which prebent reconstruction plates were used (€3346.00 ± €29.00) and cases in which they were not (€2534.22 ± €264.48; p < 0.001). Significant differences were also obtained between the costs of two, three and four devices, even when ignoring the cost of reconstruction plates. Additional fees provided by statutory health insurance covered a mean of 171.5% ± 25.6% of the cost of the CAD/CAM devices. Since the additional fees provide financial compensation, we believe that the CAD/CAM technique is suited for wide application and not restricted to complex cases. Where additional fees/funds are not available, the CAD/CAM technique might be unprofitable, so the decision whether or not to use it remains a case-to-case decision with respect to cost versus benefit.

  12. Evolution of Geometric Sensitivity Derivatives from Computer Aided Design Models

    NASA Technical Reports Server (NTRS)

    Jones, William T.; Lazzara, David; Haimes, Robert

    2010-01-01

    The generation of design parameter sensitivity derivatives is required for gradient-based optimization. Such sensitivity derivatives are elusive at best when working with geometry defined within the solid modeling context of Computer-Aided Design (CAD) systems. Solid modeling CAD systems are often proprietary and always complex, thereby necessitating ad hoc procedures to infer parameter sensitivity. A new perspective is presented that makes direct use of the hierarchical associativity of CAD features to trace their evolution and thereby track design parameter sensitivity. In contrast to ad hoc methods, this method provides a more concise procedure following the model design intent and determining the sensitivity of CAD geometry directly to its respective defining parameters.

  13. The ergonomics of computer aided design within advanced manufacturing technology.

    PubMed

    John, P A

    1988-03-01

    Many manufacturing companies have now awakened to the significance of computer aided design (CAD), although the majority of them have only been able to purchase computerised draughting systems of which only a subset produce direct manufacturing data. Such companies are moving steadily towards the concept of computer integrated manufacture (CIM), and this demands CAD to address more than draughting. CAD architects are thus having to rethink the basic specification of such systems, although they typically suffer from an insufficient understanding of the design task and have consequently been working with inadequate specifications. It is at this fundamental level that ergonomics has much to offer, making its contribution by encouraging user-centred design. The discussion considers the relationships between CAD and: the design task; the organisation and people; creativity; and artificial intelligence. It finishes with a summary of the contribution of ergonomics.

  14. Use of CAD output to guide the intelligent display of digital mammograms

    NASA Astrophysics Data System (ADS)

    Bloomquist, Aili K.; Yaffe, Martin J.; Mawdsley, Gordon E.; Morgan, Trevor; Rico, Dan; Jong, Roberta A.

    2003-05-01

    For digital mammography to be efficient, methods are needed to choose an initial default image presentation that maximizes the amount of relevant information perceived by the radiologist and minimizes the amount of time spent adjusting the image display parameters. The purpose of this work is to explore the possibility of using the output of computer aided detection (CAD) software to guide image enhancement and presentation. A set of 16 digital mammograms with lesions of known pathology was used to develop and evaluate an enhancement and display protocol to improve the initial softcopy presentation of digital mammograms. Lesions were identified by CAD and the DICOM structured report produced by the CAD program was used to determine what enhancement algorithm should be applied in the identified regions of the image. An improved version of contrast limited adaptive histogram equalization (CLAHE) is used to enhance calcifications. For masses, the image is first smoothed using a non-linear diffusion technique; subsequently, local contrast is enhanced with a method based on morphological operators. A non-linear lookup table is automatically created to optimize the contrast in the regions of interest (detected lesions) without losing the context of the periphery of the breast. The effectiveness of the enhancement will be compared with the default presentation of the images using a forced choice preference study.

  15. A combined fuzzy AHP-simulation approach to CAD software selection

    NASA Astrophysics Data System (ADS)

    Ayağ, Zeki

    2010-10-01

    In this paper, a combined approach, where the fuzzy analytic hierarchy process (AHP) and simulation come together, is presented to select the best computer-aided design (CAD) software out of the available options in the market. The fuzzy AHP is used due to the vagueness and uncertainty of the judgements of a decision maker(s), because the crisp pair-wise comparison in the conventional AHP seems to be insufficient and imprecise to capture the right judgements of the decision maker(s). In this study, first the fuzzy AHP is used to reduce a possible number of alternatives for the CAD system to an acceptable level for further study, simulation analysis. Secondly, a simulation generator as an integrated part of the fuzzy AHP is used to try the remaining alternatives, on the generated model of a real-life product organisation in which the final alternative will be used. The results of simulation experiments are obtained, and then evaluated to reach to the ultimate CAD alternative.

  16. Symmetry-based detection and diagnosis of DCIS in breast MRI

    NASA Astrophysics Data System (ADS)

    Srikantha, Abhilash; Harz, Markus T.; Newstead, Gillian; Wang, Lei; Platel, Bram; Hegenscheid, Katrin; Mann, Ritse M.; Hahn, Horst K.; Peitgen, Heinz-Otto

    2013-02-01

    The delineation and diagnosis of non-mass-like lesions, most notably DCIS (ductal carcinoma in situ), is among the most challenging tasks in breast MRI reading. Even for human observers, DCIS is not always easy to diferentiate from patterns of active parenchymal enhancement or from benign alterations of breast tissue. In this light, it is no surprise that CADe/CADx approaches often completely fail to classify DCIS. Of the several approaches that have tried to devise such computer aid, none achieve performances similar to mass detection and classification in terms of sensitivity and specificity. In our contribution, we show a novel approach to combine a newly proposed metric of anatomical breast symmetry calculated on subtraction images of dynamic contrast-enhanced (DCE) breast MRI, descriptive kinetic parameters, and lesion candidate morphology to achieve performances comparable to computer-aided methods used for masses. We have based the development of the method on DCE MRI data of 18 DCIS cases with hand-annotated lesions, complemented by DCE-MRI data of nine normal cases. We propose a novel metric to quantify the symmetry of contralateral breasts and derive a strong indicator for potentially malignant changes from this metric. Also, we propose a novel metric for the orientation of a finding towards a fix point (the nipple). Our combined scheme then achieves a sensitivity of 89% with a specificity of 78%, matching CAD results for breast MRI on masses. The processing pipeline is intended to run on a CAD server, hence we designed all processing to be automated and free of per-case parameters. We expect that the detection results of our proposed non-mass aimed algorithm will complement other CAD algorithms, or ideally be joined with them in a voting scheme.

  17. [Cerebral lesions in AIDS: what can be expected from scintigraphy? Cerebral tomographic scintigraphy using thallium-201: a contribution to the differential diagnosis of lymphomas and infectious lesions].

    PubMed

    Berry, I; Gaillard, J F; Guo, Z; Cordoliani, Y S; Massip, P; Manelfe, C; Danet, B

    1995-09-01

    CT and MRI are not consistently able to differentiate central nervous system (CNS) lymphoma from focal cerebral infection such as toxoplasmosis in the human immunodeficiency virus (HIV) involvement. In this study thallium 201 (and/or technetium-MIBI) SPECT was performed in 6 patients suffering from AIDS and CNS lesions. An index based on the ratio of thallium uptake in the lesion vs the contralateral scalp was calculated. In 4 out of 5 patients with lymphoma (3 confirmed by biopsy, 2 highly suspected on CT and resistance to antitoxoplasmosis treatment) focal lesions showed high uptake of thallium. On the other hand one markedly necrotic lymphoma and all infectious lesions did not take up thallium. This suggests a role for thallium 201 brain SPECT in the workup of focal CNS lesions in AIDS.

  18. Computer-aided detection as a decision assistant in chest radiography

    NASA Astrophysics Data System (ADS)

    Samulski, Maurice R. M.; Snoeren, Peter R.; Platel, Bram; van Ginneken, Bram; Hogeweg, Laurens; Schaefer-Prokop, Cornelia; Karssemeijer, Nico

    2011-03-01

    Background. Contrary to what may be expected, finding abnormalities in complex images like pulmonary nodules in chest radiographs is not dominated by time-consuming search strategies but by an almost immediate global interpretation. This was already known in the nineteen-seventies from experiments with briefly flashed chest radiographs. Later on, experiments with eye-trackers showed that abnormalities attracted the attention quite fast but often without further reader actions. Prolonging one's search seldom leads to newly found abnormalities and may even increase the chance of errors. The problem of reading chest radiographs is therefore not dominated by finding the abnormalities, but by interpreting them. Hypothesis. This suggests that readers could benefit from computer-aided detection (CAD) systems not so much by their ability to prompt potential abnormalities, but more from their ability to 'interpret' the potential abnormalities. In this paper, this hypothesis was investigated by an observer experiment. Experiment. In one condition, the traditional CAD condition, the most suspicious CAD locations were shown to the subjects, without telling them the levels of suspiciousness according to CAD. In the other condition, interactive CAD condition, levels of suspiciousness were given, but only when readers requested them at specified locations. These two conditions focus on decreasing search errors and decision errors, respectively. Results of reading without CAD were also recorded. Six subjects, all non-radiologists, read 223 chest radiographs in both conditions. CAD results were obtained from the OnGuard 5.0 system developed by Riverain Medical (Miamisburg, Ohio). Results. The observer data were analyzed by Location Response Operating Characteristic analysis (LROC). It was found that: 1) With the aid of CAD, the performance is significantly better than without CAD; 2) The performance with interactive CAD is significantly better than with traditional CAD at low false

  19. Full-mouth rehabilitation with monolithic CAD/CAM-fabricated hybrid and all-ceramic materials: A case report and 3-year follow up.

    PubMed

    Selz, Christian F; Vuck, Alexander; Guess, Petra C

    2016-02-01

    Esthetic full-mouth rehabilitation represents a great challenge for clinicians and dental technicians. Computer-aided design/ computer-assisted manufacture (CAD/CAM) technology and novel ceramic materials in combination with adhesive cementation provide a reliable, predictable, and economic workflow. Polychromatic feldspathic CAD/CAM ceramics that are specifically designed for anterior indications result in superior esthetics, whereas novel CAD/CAM hybrid ceramics provide sufficient fracture resistance and adsorption of the occlusal load in posterior areas. Screw-retained monolithic CAD/CAM lithium disilicate crowns (ie, hybrid abutment crowns) represent a reliable and time- and cost-efficient prosthetic implant solution. This case report details a CAD/CAM approach to the full-arch rehabilitation of a 65-year-old patient with toothand implant-supported restorations and provides an overview of the applied CAD/CAM materials and the utilized chairside intraoral scanner. The esthetics, functional occlusion, and gingival and peri-implant tissues remained stable over a follow-up period of 3 years. No signs of fractures within the restorations were observed.

  20. Increasing cancer detection yield of breast MRI using a new CAD scheme of mammograms

    NASA Astrophysics Data System (ADS)

    Tan, Maxine; Aghaei, Faranak; Hollingsworth, Alan B.; Stough, Rebecca G.; Liu, Hong; Zheng, Bin

    2016-03-01

    Although breast MRI is the most sensitive imaging modality to detect early breast cancer, its cancer detection yield in breast cancer screening is quite low (< 3 to 4% even for the small group of high-risk women) to date. The purpose of this preliminary study is to test the potential of developing and applying a new computer-aided detection (CAD) scheme of digital mammograms to identify women at high risk of harboring mammography-occult breast cancers, which can be detected by breast MRI. For this purpose, we retrospectively assembled a dataset involving 30 women who had both mammography and breast MRI screening examinations. All mammograms were interpreted as negative, while 5 cancers were detected using breast MRI. We developed a CAD scheme of mammograms, which include a new quantitative mammographic image feature analysis based risk model, to stratify women into two groups with high and low risk of harboring mammography-occult cancer. Among 30 women, 9 were classified into the high risk group by CAD scheme, which included all 5 women who had cancer detected by breast MRI. All 21 low risk women remained negative on the breast MRI examinations. The cancer detection yield of breast MRI applying to this dataset substantially increased from 16.7% (5/30) to 55.6% (5/9), while eliminating 84% (21/25) unnecessary breast MRI screenings. The study demonstrated the potential of applying a new CAD scheme to significantly increase cancer detection yield of breast MRI, while simultaneously reducing the number of negative MRIs in breast cancer screening.

  1. Computer-aided detection of prostate cancer in T2-weighted MRI within the peripheral zone

    NASA Astrophysics Data System (ADS)

    Rampun, Andrik; Zheng, Ling; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-07-01

    In this paper we propose a prostate cancer computer-aided diagnosis (CAD) system and suggest a set of discriminant texture descriptors extracted from T2-weighted MRI data which can be used as a good basis for a multimodality system. For this purpose, 215 texture descriptors were extracted and eleven different classifiers were employed to achieve the best possible results. The proposed method was tested based on 418 T2-weighted MR images taken from 45 patients and evaluated using 9-fold cross validation with five patients in each fold. The results demonstrated comparable results to existing CAD systems using multimodality MRI. We achieved an area under the receiver operating curve (A z ) values equal to 90.0%+/- 7.6% , 89.5%+/- 8.9% , 87.9%+/- 9.3% and 87.4%+/- 9.2% for Bayesian networks, ADTree, random forest and multilayer perceptron classifiers, respectively, while a meta-voting classifier using average probability as a combination rule achieved 92.7%+/- 7.4% .

  2. A dimension reduction strategy for improving the efficiency of computer-aided detection for CT colonography

    NASA Astrophysics Data System (ADS)

    Song, Bowen; Zhang, Guopeng; Wang, Huafeng; Zhu, Wei; Liang, Zhengrong

    2013-02-01

    Various types of features, e.g., geometric features, texture features, projection features etc., have been introduced for polyp detection and differentiation tasks via computer aided detection and diagnosis (CAD) for computed tomography colonography (CTC). Although these features together cover more information of the data, some of them are statistically highly-related to others, which made the feature set redundant and burdened the computation task of CAD. In this paper, we proposed a new dimension reduction method which combines hierarchical clustering and principal component analysis (PCA) for false positives (FPs) reduction task. First, we group all the features based on their similarity using hierarchical clustering, and then PCA is employed within each group. Different numbers of principal components are selected from each group to form the final feature set. Support vector machine is used to perform the classification. The results show that when three principal components were chosen from each group we can achieve an area under the curve of receiver operating characteristics of 0.905, which is as high as the original dataset. Meanwhile, the computation time is reduced by 70% and the feature set size is reduce by 77%. It can be concluded that the proposed method captures the most important information of the feature set and the classification accuracy is not affected after the dimension reduction. The result is promising and further investigation, such as automatically threshold setting, are worthwhile and are under progress.

  3. Teach CAD and Measuring Skills through Reverse Engineering

    ERIC Educational Resources Information Center

    Board, Keith

    2012-01-01

    This article describes a reverse engineering activity that gives students hands-on, minds-on experience with measuring tools, machine parts, and CAD. The author developed this activity to give students an abundance of practical experience with measuring tools. Equally important, it provides a good interface between the virtual world of CAD 3D…

  4. CAD/CAM: Practical and Persuasive in Canadian Schools

    ERIC Educational Resources Information Center

    Willms, Ed

    2007-01-01

    Chances are that many high school students would not know how to use drafting instruments, but some might want to gain competence in computer-assisted design (CAD) and possibly computer-assisted manufacturing (CAM). These students are often attracted to tech courses by the availability of CAD/CAM instructions, and many go on to impress employers…

  5. Evaluating the Learning Process of Mechanical CAD Students

    ERIC Educational Resources Information Center

    Hamade, R. F.; Artail, H. A.; Jaber, M. Y.

    2007-01-01

    There is little theoretical or experimental research on how beginner-level trainees learn CAD skills in formal training sessions. This work presents findings on how trainees develop their skills in utilizing a solid mechanical CAD tool (Pro/Engineer version 2000i[squared] and later version Wildfire). Exercises at the beginner and intermediate…

  6. Making a Case for CAD in the Curriculum.

    ERIC Educational Resources Information Center

    Threlfall, K. Denise

    1995-01-01

    Computer-assisted design (CAD) technology is transforming the apparel industry. Students of fashion merchandising and clothing design must be prepared on state-of-the-art equipment. ApparelCAD software is one example of courseware for instruction in pattern design and production. (SK)

  7. A rule based computer aided design system

    NASA Technical Reports Server (NTRS)

    Premack, T.

    1986-01-01

    A Computer Aided Design (CAD) system is presented which supports the iterative process of design, the dimensional continuity between mating parts, and the hierarchical structure of the parts in their assembled configuration. Prolog, an interactive logic programming language, is used to represent and interpret the data base. The solid geometry representing the parts is defined in parameterized form using the swept volume method. The system is demonstrated with a design of a spring piston.

  8. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication.

    PubMed

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now.

  9. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication.

    PubMed

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  10. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

    PubMed Central

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  11. Radiologists’ Perceptions of Computer Aided Detection versus Double Reading for Mammography Interpretation

    PubMed Central

    Onega, Tracy; Aiello Bowles, Erin J.; Miglioretti, Diana L.; Carney, Patricia A.; Geller, Berta M.; Yankaskas, Bonnie C.; Kerlikowske, Karla; Sickles, Edward A.; Elmore, Joann G.

    2011-01-01

    Rationale and Objectives To examine radiologists’ use and perceptions of computer-aided detection (CAD) and double reading for screening mammography interpretation. Materials and Methods A mailed survey of 257 community radiologists participating in the national Breast Cancer Surveillance Consortium assessed perceptions and practices related to CAD and double reading. We used latent class analysis to classify radiologists’ overall perceptions of CAD and double reading based on their agreement or disagreement with specific statements about CAD and double reading. Results Most radiologists (64%) reported using CAD for more than half the screening mammograms they interpreted, but only <5% reported double reading that much. More radiologists perceived that double reading improved cancer detection rates compared with CAD (74% vs. 55% reported), while fewer radiologists thought that double reading decreased recall rates compared with CAD (50% vs. 65% reported). Radiologists with the most favorable perceptions of CAD were more likely to think that CAD improved cancer detection rate without taking too much time compared with radiologists with the most unfavorable overall perceptions. In latent class analysis an overall favorable perception of CAD was significantly associated with use of CAD (81%), higher percent of workload in screening mammography (80%), academic affiliation (71%), and fellowship training (58%). Perceptions of double reading that were most favorable were associated with academic affiliation (98%). Conclusion Radiologists’ perceptions were more favorable toward double reading by a second clinician than by a computer, although fewer used double reading in their own practice. The majority of radiologists perceived both CAD and double reading at least somewhat favorably, although for largely different reasons. PMID:20832024

  12. Amalgam tattoo: report of an unusual clinical presentation and the use of energy dispersive X-ray analysis as an aid to diagnosis

    SciTech Connect

    McGinnis, J.P. Jr.; Greer, J.L.; Daniels, D.S.

    1985-01-01

    An unusual appearing gingival amalgam pigmentation (amalgam tattoo) that completely surrounded the maxillary right first premolar in a 13-year-old boy is presented. Because of the wide distribution and apparent clinical progression of the discoloration, an excisional biopsy was performed. The histopathologic diagnosis of amalgam pigmentation was confirmed in paraffin sections by energy dispersive X-ray microanalysis. Silver, tin, and mercury were detected in the specimen.

  13. Multiplex diagnosis of viral infectious diseases (AIDS, hepatitis C, and hepatitis A) based on point of care lateral flow assay using engineered proteinticles.

    PubMed

    Lee, Jong-Hwan; Seo, Hyuk Seong; Kwon, Jung-Hyuk; Kim, Hee-Tae; Kwon, Koo Chul; Sim, Sang Jun; Cha, Young Joo; Lee, Jeewon

    2015-07-15

    Lateral flow assay (LFA) is an attractive method for rapid, simple, and cost-effective point of care diagnosis. For LFA-based multiplex diagnosis of three viral intractable diseases (acquired immune deficiency syndrome and hepatitis C and A), here we developed proteinticle-based 7 different 3D probes that display different viral antigens on their surface, which were synthesized in Escherichia coli by self-assembly of human ferritin heavy chain that was already engineered by genetically linking viral antigens to its C-terminus. Each of the three test lines on LFA strip contains the proteinticle probes to detect disease-specific anti-viral antibodies. Compared to peptide probes, the proteinticle probes were evidently more sensitive, and the proteinticle probe-based LFA successfully diagnosed all the 20 patient sera per each disease without a false negative signal, whereas the diagnostic sensitivities in the peptide probe-based LFAs were 65-90%. Duplex and triplex assays performed with randomly mixed patient sera gave only true positive signals for all the 20 serum mixtures without any false positive signals, indicating 100% sensitivity and 100% specificity. It seems that on the proteinticle surface the antigenic peptides have homogeneous orientation and conformation without inter-peptide clustering and hence lead to the enhanced diagnostic performance with solving the problems of traditional diagnostic probes. Although the multiplex diagnosis of three viral diseases above was demonstrated as proof-of-concept here, the proposed LFA system can be applied to multiplex point of care diagnosis of other intractable diseases.

  14. Assessment of Chair-side Computer-Aided Design and Computer-Aided Manufacturing Restorations: A Review of the Literature

    PubMed Central

    Baroudi, Kusai; Ibraheem, Shukran Nasser

    2015-01-01

    Background: This paper aimed to evaluate the application of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and the factors that affect the survival of restorations. Materials and Methods: A thorough literature search using PubMed, Medline, Embase, Science Direct, Wiley Online Library and Grey literature were performed from the year 2004 up to June 2014. Only relevant research was considered. Results: The use of chair-side CAD/CAM systems is promising in all dental branches in terms of minimizing time and effort made by dentists, technicians and patients for restoring and maintaining patient oral function and aesthetic, while providing high quality outcome. Conclusion: The way of producing and placing the restorations made with the chair-side CAD/CAM (CEREC and E4D) devices is better than restorations made by conventional laboratory procedures. PMID:25954082

  15. Fracture Rates and Lifetime Estimations of CAD/CAM All-ceramic Restorations.

    PubMed

    Belli, R; Petschelt, A; Hofner, B; Hajtó, J; Scherrer, S S; Lohbauer, U

    2016-01-01

    The gathering of clinical data on fractures of dental restorations through prospective clinical trials is a labor- and time-consuming enterprise. Here, we propose an unconventional approach for collecting large datasets, from which clinical information on indirect restorations can be retrospectively analyzed. The authors accessed the database of an industry-scale machining center in Germany and obtained information on 34,911 computer-aided design (CAD)/computer-aided manufacturing (CAM) all-ceramic posterior restorations. The fractures of bridges, crowns, onlays, and inlays fabricated from different all-ceramic systems over a period of 3.5 y were reported by dentists and entered in the database. Survival analyses and estimations of future life revealed differences in performance among ZrO2-based restorations and lithium disilicate and leucite-reinforced glass-ceramics.

  16. Fracture Rates and Lifetime Estimations of CAD/CAM All-ceramic Restorations.

    PubMed

    Belli, R; Petschelt, A; Hofner, B; Hajtó, J; Scherrer, S S; Lohbauer, U

    2016-01-01

    The gathering of clinical data on fractures of dental restorations through prospective clinical trials is a labor- and time-consuming enterprise. Here, we propose an unconventional approach for collecting large datasets, from which clinical information on indirect restorations can be retrospectively analyzed. The authors accessed the database of an industry-scale machining center in Germany and obtained information on 34,911 computer-aided design (CAD)/computer-aided manufacturing (CAM) all-ceramic posterior restorations. The fractures of bridges, crowns, onlays, and inlays fabricated from different all-ceramic systems over a period of 3.5 y were reported by dentists and entered in the database. Survival analyses and estimations of future life revealed differences in performance among ZrO2-based restorations and lithium disilicate and leucite-reinforced glass-ceramics. PMID:26428908

  17. Marginal fit of anterior 3-unit fixed partial zirconia restorations using different CAD/CAM systems

    PubMed Central

    Song, Tae-Jin; Kwon, Taek-Ka; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metal-ceramic FPDs. MATERIALS AND METHODS Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs. They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using one-way ANOVA and Duncan test. RESULTS Mean marginal gaps of 3-unit FPDs were 60.46 µm for the Everest group, 78.71 µm for the Lava group, and 81.32 µm for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P<.05). The marginal gap did not significantly differ between the Lava and the metal-ceramic groups (P>.05). CONCLUSION The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration. PMID:24049561

  18. Use of the frozen section 'jelly-roll' technique to aid in the diagnosis of bullous congenital ichthyosiform erythroderma (epidermolytic hyperkeratosis).

    PubMed

    Galler, Blake; Bowen, Casey; Arnold, Jason; Kobayashi, Todd; Dalton, Scott R

    2016-05-01

    Frozen section is a valuable tool that is often underutilized in the setting of in-patient dermatology. Traditionally, frozen section has been used in dermatology to diagnose toxic epidermal necrolysis, with some additional utility in staphylococcal scalded skin syndrome in the new born period. We report a newborn female with ruptured bullae on the face, chest, back and extremities with a clinical differential diagnosis that included staphylococcal scalded skin, bullous congenital ichthyosiform erythroderma/epidermolytic hyperkeratosis and epidermolysis bullosa. A thin detached skin sample ('jelly-roll') taken from a ruptured bulla on the abdomen was prepared for frozen section analysis. Characteristic findings of epidermolytic hyperkeratosis were seen which included hyperkeratosis with granular layer degeneration, vacuolization and eosinophilic globules. The 'jelly-roll' technique can be used for quick diagnosis with minimal trauma to the patient. Epidermolytic hyperkeratosis was subsequently confirmed by a biopsy fixed in formalin and by genetic testing. A novel missense mutation in KRT1 (I479N) was identified. Herein, we discuss the use of the frozen section 'jelly roll' technique for rapid diagnosis in a case of bullous congenital ichthyosis erythroderma/epidermolytic hyperkeratosis. PMID:26969483

  19. Use of the frozen section 'jelly-roll' technique to aid in the diagnosis of bullous congenital ichthyosiform erythroderma (epidermolytic hyperkeratosis).

    PubMed

    Galler, Blake; Bowen, Casey; Arnold, Jason; Kobayashi, Todd; Dalton, Scott R

    2016-05-01

    Frozen section is a valuable tool that is often underutilized in the setting of in-patient dermatology. Traditionally, frozen section has been used in dermatology to diagnose toxic epidermal necrolysis, with some additional utility in staphylococcal scalded skin syndrome in the new born period. We report a newborn female with ruptured bullae on the face, chest, back and extremities with a clinical differential diagnosis that included staphylococcal scalded skin, bullous congenital ichthyosiform erythroderma/epidermolytic hyperkeratosis and epidermolysis bullosa. A thin detached skin sample ('jelly-roll') taken from a ruptured bulla on the abdomen was prepared for frozen section analysis. Characteristic findings of epidermolytic hyperkeratosis were seen which included hyperkeratosis with granular layer degeneration, vacuolization and eosinophilic globules. The 'jelly-roll' technique can be used for quick diagnosis with minimal trauma to the patient. Epidermolytic hyperkeratosis was subsequently confirmed by a biopsy fixed in formalin and by genetic testing. A novel missense mutation in KRT1 (I479N) was identified. Herein, we discuss the use of the frozen section 'jelly roll' technique for rapid diagnosis in a case of bullous congenital ichthyosis erythroderma/epidermolytic hyperkeratosis.

  20. AIDS (image)

    MedlinePlus

    AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that ... life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. ...

  1. Hearing Aids

    MedlinePlus

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  2. Multi-Modal Neuroimaging Feature Learning for Multi-Class Diagnosis of Alzheimer’s Disease

    PubMed Central

    Liu, Siqi; Liu, Sidong; Cai, Weidong; Che, Hangyu; Pujol, Sonia; Kikinis, Ron; Feng, Dagan; Fulham, Michael J.

    2015-01-01

    The accurate diagnosis of Alzheimers disease (AD) is essential for patient care and will be increasingly important as disease modifying agents become available, early in the course of the disease. Although studies have applied machine learning methods for the computer aided diagnosis (CAD) of AD, a bottleneck in the diagnostic performance was shown in previous methods, due to the lacking of efficient strategies for representing neuroimaging biomarkers. In this study, we designed a novel diagnostic framework with deep learning architecture to aid the diagnosis of AD. This framework uses a zero-masking strategy for data fusion to extract complementary information from multiple data modalities. Compared to the previous state-of-the-art workflows, our method is capable of fusing multi-modal neuroimaging features in one setting and has the potential to require less labelled data. A performance gain was achieved in both binary classification and multi-class classification of AD. The advantages and limitations of the proposed framework are discussed. PMID:25423647

  3. Apex radicis dentis excision operation guided by template made by CAD/CAM

    PubMed Central

    He, Zong-Lai; Cai, Su-Qing; Jin, Guang-Sheng; Liu, Yun-Feng

    2015-01-01

    Objective: The aim of the study is to explore the clinical efficacy of apex radicis dentis excision guided by a template made by Computer Aided Design/Computer Aided Manufacture (CAD/CAM). Methods: Base on the CBCT image of oral cavity, a three-dimensional model of patient’s oral cavity was built. Then the access way and excisional area were defined based on the model. Finally, the operative guide template was designed and made to help define the direction, depth, and area of the surgery. Results: One year after the operation with guide template, the two cases of apex radicis dentis with difficulty in cure were proven to have normal masticatory function and their pathological changes of apex radicis dentis disappeared as well. Conclusion: Utilization of CAD/CAM technology could well design the operative guide template for the resection of apex radicis dentis. Usingthis guide template could make the excision of apex radicis dentis more quickly and safer. PMID:26131072

  4. Luting of CAD/CAM ceramic inlays: direct composite versus dual-cure luting cement.

    PubMed

    Kameyama, Atsushi; Bonroy, Kim; Elsen, Caroline; Lührs, Anne-Katrin; Suyama, Yuji; Peumans, Marleen; Van Meerbeek, Bart; De Munck, Jan

    2015-01-01

    The aim of this study was to investigate bonding effectiveness in direct restorations. A two-step self-etch adhesive and a light-cure resin composite was compared with luting with a conventional dual-cure resin cement and a two-step etch and rinse adhesive. Class-I box-type cavities were prepared. Identical ceramic inlays were designed and fabricated with a computer-aided design/computer-aided manufacturing (CAD/CAM) device. The inlays were seated with Clearfil SE Bond/Clearfil AP-X (Kuraray Medical) or ExciTE F DSC/Variolink II (Ivoclar Vivadent), each by two operators (five teeth per group). The inlays were stored in water for one week at 37°C, whereafter micro-tensile bond strength testing was conducted. The micro-tensile bond strength of the direct composite was significantly higher than that from conventional luting, and was independent of the operator (P<0.0001). Pre-testing failures were only observed with the conventional method. High-power light-curing of a direct composite may be a viable alternative to luting lithium disilicate glass-ceramic CAD/CAM restorations. PMID:26407114

  5. Comparative study of flexural strength test methods on CAD/CAM Y-TZP dental ceramics.

    PubMed

    Xu, Yongxiang; Han, Jianmin; Lin, Hong; An, Linan

    2015-12-01

    Clinically, fractures are the main cause of computer-aided design and computer-aided manufacturing (CAD/CAM) 3 mol%-yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) all-ceramic dental restorations failure because of repetitive occlusal loading. The goal of this work is to study the effect of test methods and specimen's size on the flexural strength of five ceramic products. Both bi-axial flexure test (BI) and uni-axial flexure tests (UNI), including three-point flexure test (3PF) and four-point flexure test (4PF), are used in this study. For all five products, the flexural strength is as follows: BI > 3PF > 4PF. Furthermore, specimens with smaller size (3PF-s) have higher values than the bigger ones (3PF). The difference between BI and UNI resulted from the edge flaws in ceramic specimens. The relationship between different UNI (including 3PF-s, 3PF and 4PF) can be explained according to Weibull statistical fracture theory. BI is recommended to evaluate the flexural strength of CAD/CAM Y-TZP dental ceramics.

  6. Comparative study of flexural strength test methods on CAD/CAM Y-TZP dental ceramics

    PubMed Central

    Xu, Yongxiang; Han, Jianmin; Lin, Hong; An, Linan

    2015-01-01

    Clinically, fractures are the main cause of computer-aided design and computer-aided manufacturing (CAD/CAM) 3 mol%-yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) all-ceramic dental restorations failure because of repetitive occlusal loading. The goal of this work is to study the effect of test methods and specimen’s size on the flexural strength of five ceramic products. Both bi-axial flexure test (BI) and uni-axial flexure tests (UNI), including three-point flexure test (3PF) and four-point flexure test (4PF), are used in this study. For all five products, the flexural strength is as follows: BI > 3PF > 4PF. Furthermore, specimens with smaller size (3PF-s) have higher values than the bigger ones (3PF). The difference between BI and UNI resulted from the edge flaws in ceramic specimens. The relationship between different UNI (including 3PF-s, 3PF and 4PF) can be explained according to Weibull statistical fracture theory. BI is recommended to evaluate the flexural strength of CAD/CAM Y-TZP dental ceramics. PMID:26816646

  7. An approach to biomimetics: the natural CAD/CAM restoration: a clinical report.

    PubMed

    Schlichting, Luís Henrique; Schlichting, Kathryn Klemz; Stanley, Kyle; Magne, Michel; Magne, Pascal

    2014-02-01

    Those in the dental field have always pursued the perfect dental material for the treatment of compromised teeth. Gold, amalgam, composite resin, glass ionomer, and porcelain have been used. Tooth-like restorative materials (composite resin and porcelain) combined with an effective hard tissue bond have met the growing demand for esthetic or metal-free restorations in the past 15 to 20 years. However, none of those materials can fully mimic the unique properties of dentin (compliance and crack-stopping behavior) and enamel (wear resistance, function). The aim of this article is to report the restoration of an extensively damaged tooth with a natural restoration obtained by milling an extracted third molar tooth with a computer-aided design and computer-aided manufacturing (CAD/CAM) system. The main benefit of this novel technique is the replacement of lost tissues by actual enamel and dentin, with the potential to recover mechanical, esthetic, and biologic properties. The indication for extracting third molars and premolars because of impaction or for orthodontic reasons makes these posterior teeth readily available. The innovation of the method presented here is the optimal use of the extracted tooth substrate thanks to its positioning technique in the CAD/CAM milling chamber.

  8. Luting of CAD/CAM ceramic inlays: direct composite versus dual-cure luting cement.

    PubMed

    Kameyama, Atsushi; Bonroy, Kim; Elsen, Caroline; Lührs, Anne-Katrin; Suyama, Yuji; Peumans, Marleen; Van Meerbeek, Bart; De Munck, Jan

    2015-01-01

    The aim of this study was to investigate bonding effectiveness in direct restorations. A two-step self-etch adhesive and a light-cure resin composite was compared with luting with a conventional dual-cure resin cement and a two-step etch and rinse adhesive. Class-I box-type cavities were prepared. Identical ceramic inlays were designed and fabricated with a computer-aided design/computer-aided manufacturing (CAD/CAM) device. The inlays were seated with Clearfil SE Bond/Clearfil AP-X (Kuraray Medical) or ExciTE F DSC/Variolink II (Ivoclar Vivadent), each by two operators (five teeth per group). The inlays were stored in water for one week at 37°C, whereafter micro-tensile bond strength testing was conducted. The micro-tensile bond strength of the direct composite was significantly higher than that from conventional luting, and was independent of the operator (P<0.0001). Pre-testing failures were only observed with the conventional method. High-power light-curing of a direct composite may be a viable alternative to luting lithium disilicate glass-ceramic CAD/CAM restorations.

  9. Using CAD software to simulate PV energy yield - The case of product integrated photovoltaic operated under indoor solar irradiation

    SciTech Connect

    Reich, N.H.; van Sark, W.G.J.H.M.; Turkenburg, W.C.; Sinke, W.C.

    2010-08-15

    In this paper, we show that photovoltaic (PV) energy yields can be simulated using standard rendering and ray-tracing features of Computer Aided Design (CAD) software. To this end, three-dimensional (3-D) sceneries are ray-traced in CAD. The PV power output is then modeled by translating irradiance intensity data of rendered images back into numerical data. To ensure accurate results, the solar irradiation data used as input is compared to numerical data obtained from rendered images, showing excellent agreement. As expected, also ray-tracing precision in the CAD software proves to be very high. To demonstrate PV energy yield simulations using this innovative concept, solar radiation time course data of a few days was modeled in 3-D to simulate distributions of irradiance incident on flat, single- and double-bend shapes and a PV powered computer mouse located on a window sill. Comparisons of measured to simulated PV output of the mouse show that also in practice, simulation accuracies can be very high. Theoretically, this concept has great potential, as it can be adapted to suit a wide range of solar energy applications, such as sun-tracking and concentrator systems, Building Integrated PV (BIPV) or Product Integrated PV (PIPV). However, graphical user interfaces of 'CAD-PV' software tools are not yet available. (author)

  10. Hearing Aids

    MedlinePlus

    ... type and degree of loss. Are there different styles of hearing aids? Styles of hearing aids Source: NIH/NIDCD Behind-the- ... the ear canal and are available in two styles. The in-the-canal (ITC) hearing aid is ...

  11. Performance Testing of PCR Assay in Blood Samples for the Diagnosis of Toxoplasmic Encephalitis in AIDS Patients from the French Departments of America and Genetic Diversity of Toxoplasma gondii: A Prospective and Multicentric Study

    PubMed Central

    Ajzenberg, Daniel; Lamaury, Isabelle; Demar, Magalie; Vautrin, Cyrille; Cabié, André; Simon, Stéphane; Nicolas, Muriel; Desbois-Nogard, Nicole; Boukhari, Rachida; Riahi, Homayoun; Dardé, Marie-Laure; Massip, Patrice; Dupon, Michel; Preux, Pierre-Marie; Labrunie, Anaïs; Boncoeur, Marie-Paule

    2016-01-01

    Background Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana. Methodology/Principal Findings Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay. Conclusion/Significance Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains. Trial Registration ClinicalTrials.gov NCT00803621 PMID:27355620

  12. SAFE for PTSD: noncontact psychophysiological measure based on high-resolution thermal imaging to aid in PTSD diagnosis and assessment of treatment

    NASA Astrophysics Data System (ADS)

    Familoni, Babajide O.; Ma, Lein; Hutchinson, J. Andrew; Morgan, C. Andrew, III; Rasmusson, Ann; O'Kane, Barbara L.

    2012-06-01

    Post Traumatic Stress Disorder (PTSD) sometimes develops following exposure to very stressful or traumatic events such as motor vehicle accidents, rape, and war. It is arguably the signature injury of the conflicts in Iraq and Afghanistan. Previous studies have demonstrated that PTSD sufferers exhibit autonomic hyper-responsiveness to both neutral and trauma-related stimuli. In this study, we propose using high resolution thermal imaging of sweat-pores to obtain a noncontact, remote, and quantifiable measure of the sympathetic autonomic nervous reactivity to guide diagnosis, assess response to treatment, and tease out important cues to suicidality as a PTSD comorbidity.

  13. CAD-centric Computation Management System for a Virtual TBM

    SciTech Connect

    Ramakanth Munipalli; K.Y. Szema; P.Y. Huang; C.M. Rowell; A.Ying; M. Abdou

    2011-05-03

    HyPerComp Inc. in research collaboration with TEXCEL has set out to build a Virtual Test Blanket Module (VTBM) computational system to address the need in contemporary fusion research for simulating the integrated behavior of the blanket, divertor and plasma facing components in a fusion environment. Physical phenomena to be considered in a VTBM will include fluid flow, heat transfer, mass transfer, neutronics, structural mechanics and electromagnetics. We seek to integrate well established (third-party) simulation software in various disciplines mentioned above. The integrated modeling process will enable user groups to interoperate using a common modeling platform at various stages of the analysis. Since CAD is at the core of the simulation (as opposed to computational meshes which are different for each problem,) VTBM will have a well developed CAD interface, governing CAD model editing, cleanup, parameter extraction, model deformation (based on simulation,) CAD-based data interpolation. In Phase-I, we built the CAD-hub of the proposed VTBM and demonstrated its use in modeling a liquid breeder blanket module with coupled MHD and structural mechanics using HIMAG and ANSYS. A complete graphical user interface of the VTBM was created, which will form the foundation of any future development. Conservative data interpolation via CAD (as opposed to mesh-based transfer), the regeneration of CAD models based upon computed deflections, are among the other highlights of phase-I activity.

  14. Investigation of IGES for CAD/CAE data transfer

    NASA Technical Reports Server (NTRS)

    Zobrist, George W.

    1989-01-01

    In a CAD/CAE facility there is always the possibility that one may want to transfer the design graphics database from the native system to a non-native system. This may occur because of dissimilar systems within an organization or a new CAD/CAE system is to be purchased. The Initial Graphics Exchange Specification (IGES) was developed in an attempt to solve this scenario. IGES is a neutral database format into which the CAD/CAE native database format can be translated to and from. Translating the native design database format to IGES requires a pre-processor and transling from IGES to the native database format requires a post-processor. IGES is an artifice to represent CAD/CAE product data in a neutral environment to allow interfacing applications, archive the database, interchange of product data between dissimilar CAD/CAE systems, and other applications. The intent here is to present test data on translating design product data from a CAD/CAE system to itself and to translate data initially prepared in IGES format to various native design formats. This information can be utilized in planning potential procurement and developing a design discipline within the CAD/CAE community.

  15. Use of computer aided drafting for analysis and control of posture in manual work.

    PubMed

    Ulin, S S; Armstrong, T J; Radwin, R G

    1990-06-01

    Computer aided design (CAD) in conjunction with digitised anthropometric manikins can be used for analysis and control of stressful work postures, one of the most frequently cited occupational risk factors of upper extremity cumulative trauma disorders. This paper describes the use of macros for manipulating manikins and workstation components and for designing the workplace. AutoCAD, a popular computer aided design software package, was used to demonstrate the feasibility of these concepts. Specifically, macros are used for drawing work equipment using parametric designs, manipulating manikins and analysing jobs. In comparing the macros to the use of primitive CAD commands, the macros not only decrease the amount of time needed to create workstation components, but they also make the task easier for the user and decrease the risk of errors. Despite the limitation of anthropometric data and manikins, CAD is an effective method for identifying postural stresses and redesigning the workstation to control the identified stresses. PMID:15676770

  16. Age-at-death diagnosis and determination of life-history parameters by incremental lines in human dental cementum as an identification aid.

    PubMed

    Kagerer, P; Grupe, G

    2001-04-15

    Incremental lines in acellular extrinsic fiber cementum of 91 roots from 80 freshly extracted teeth have been investigated for a verification of the suitability of pathological teeth for a valid age-at-death diagnosis. Independent from tooth type, the accuracy of histological age-at-death diagnosis is clearly a function of a tooth's pathological state. Various periodontal diseases lead to a reduced number of incremental lines, while teeth with a sufficient nutritional support of their root showed a deviation of the histological age from the known actual age of 2-3 years only. For all patients, a detailed query concerning a variety of life-history parameters was established. We are able to show that especially previous pregnancies, skeletal traumata and renal diseases which all have a marked influence on the calcium metabolism result in hypomineralized incremental lines. The year of production of these hypomineralized lines could be dated precisely. Differential quality of incremental lines can, therefore, serve as a valuable tool in identification cases. PMID:11343858

  17. Automatic Detection of Calcaneal-Fifth Metatarsal Angle Using Radiograph: A Computer-Aided Diagnosis of Flat Foot for Military New Recruits in Taiwan

    PubMed Central

    Yang, Chin-Hua; Chou, Kuei-Ting; Chung, Mu-Bai; Chuang, K. S.; Huang, Tzung-Chi

    2015-01-01

    Flatfoot (pes planus) is one of the most important physical examination items for military new recruits in Taiwan. Currently, the diagnosis of flatfoot is mainly based on radiographic examination of the calcaneal-fifth metatarsal (CA–MT5) angle, also known as the arch angle. However, manual measurement of the arch angle is time-consuming and often inconsistent between different examiners. In this study, seventy male military new recruits were studied. Lateral radiographic images of their right and left feet were obtained, and mutual information (MI) registration was used to automatically calculate the arch angle. Images of two critical bones, the calcaneus and the fifth metatarsal bone, were isolated from the lateral radiographs to form reference images, and were then compared with template images to calculate the arch angle. The result of this computer-calculated arch angle was compared with manual measurement results from two radiologists, which showed that our automatic arch angle measurement method had a high consistency. In addition, this method had a high accuracy of 97% and 96% as compared with the measurements of radiologists A and B, respectively. The findings indicated that our MI registration measurement method cannot only accurately measure the CA–MT5 angle, but also saves time and reduces human error. This method can increase the consistency of arch angle measurement and has potential clinical application for the diagnosis of flatfoot. PMID:26126115

  18. Effect of the Crystallization Process on the Marginal and Internal Gaps of Lithium Disilicate CAD/CAM Crowns

    PubMed Central

    Kim, Jae-Hong; Oh, Seunghan; Uhm, Soo-Hyuk

    2016-01-01

    The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice—before and after crystallization—using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a paired t-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α = 0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P < 0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120 μm, which is the clinically acceptable threshold. PMID:27123453

  19. Effect of the Crystallization Process on the Marginal and Internal Gaps of Lithium Disilicate CAD/CAM Crowns.

    PubMed

    Kim, Jae-Hong; Oh, Seunghan; Uhm, Soo-Hyuk

    2016-01-01

    The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice-before and after crystallization-using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a paired t-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α = 0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P < 0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120 μm, which is the clinically acceptable threshold. PMID:27123453

  20. Turnkey CAD/CAM systems' integration with IPAD systems

    NASA Technical Reports Server (NTRS)

    Blauth, R. E.

    1980-01-01

    Today's commercially available turnkey CAD/CAM systems provide a highly interactive environment, and support many specialized application functions for the design/drafting/manufacturing process. This paper presents an overview of several aerospace companies which have successfully integrated turnkey CAD/CAM systems with their own company wide engineering and manufacturing systems. It also includes a vendor's view of the benefits as well as the disadvantages of such integration efforts. Specific emphasis is placed upon the selection of standards for representing geometric engineering data and for communicating such information between different CAD/CAM systems.