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Sample records for response imaging evaluation

  1. Imaging in evaluation of response to neoadjuvant breast cancer treatment

    PubMed Central

    Ollivier, L; Balu-Maestro, C; Leclère, J

    2005-01-01

    The role of imaging for patients treated with neoadjuvant therapy for breast cancer is not only to evaluate the therapeutic response in terms of tumour shrinkage, but also to predict the histological response to chemotherapy, which is correlated to survival. Surgery and histopathological analysis after neoadjuvant therapy allow for an objective assessment of the accuracy of imaging techniques in evaluating response. The aim of this study is to compare the value of the different conventional and functional imaging techniques for determining response to neoadjuvant chemotherapy in breast cancer treatment. PMID:16154816

  2. Visible hyperspectral imaging evaluating the cutaneous response to ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Ilias, Michail A.; Häggblad, Erik; Anderson, Chris; Salerud, E. Göran

    2007-02-01

    In vivo diagnostics of skin diseases as well as understanding of the skin biology constitute a field demanding characterization of physiological and anatomical parameters. Biomedical optics has been successfully used, to qualitatively and quantitatively estimate the microcirculatory conditions of superficial skin. Capillaroscopy, laser Doppler techniques and spectroscopy, all elucidate different aspects of microcirculation, e.g. capillary anatomy and distribution, tissue perfusion and hemoglobin oxygenation. We demonstrate the use of a diffuse reflectance hyperspectral imaging system for spatial and temporal characterization of tissue oxygenation, important to skin viability. The system comprises: light source, liquid crystal tunable filter, camera objective, CCD camera, and the decomposition of the spectral signature into relative amounts of oxy- and deoxygenized hemoglobin as well as melanin in every pixel resulting in tissue chromophore images. To validate the system, we used a phototesting model, creating a graded inflammatory response of a known geometry, in order to evaluate the ability to register spatially resolved reflectance spectra. The obtained results demonstrate the possibility to describe the UV inflammatory response by calculating the change in tissue oxygen level, intimately connected to a tissue's metabolism. Preliminary results on the estimation of melanin content are also presented.

  3. Computerized PET/CT image analysis in the evaluation of tumour response to therapy

    PubMed Central

    Wang, J; Zhang, H H

    2015-01-01

    Current cancer therapy strategy is mostly population based, however, there are large differences in tumour response among patients. It is therefore important for treating physicians to know individual tumour response. In recent years, many studies proposed the use of computerized positron emission tomography/CT image analysis in the evaluation of tumour response. Results showed that computerized analysis overcame some major limitations of current qualitative and semiquantitative analysis and led to improved accuracy. In this review, we summarize these studies in four steps of the analysis: image registration, tumour segmentation, image feature extraction and response evaluation. Future works are proposed and challenges described. PMID:25723599

  4. Prediction and Early Evaluation of Anticancer Therapy Response: From Imaging of Drug Efflux Pumps to Targeted Therapy Response.

    PubMed

    Meng, Qingqing; Li, Zheng; Li, Shaoshun

    2016-01-01

    Multidrug resistance (MDR) describes the resistance of tumor cells to chemotherapy and has been ascribed to the overexpression of drug efflux pumps. Molecular imaging of drug efflux pumps is helpful to identify the patients who may be resistant to the chemotherapy and thus will avoid the unnecessary treatment and increase the therapeutic effectiveness. Imaging probes targeting drug efflux pumps can non-invasively evaluate the Pgp function and play an important role in identification of MDR, prediction of response, and monitoring MDR modulation. On the other hand, new anticancer agents based on molecular targets such as epidermal growth factor receptor (EGFR) and angiogenic factor receptor may potentially be combined with chemotherapeutic drugs to overcome the MDR. Imaging of molecular targets visualize treatment response of patients at molecular level vividly and help to select right patients for certain targeted anticancer therapy. Among all the imaging modalities, nuclear imaging including positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging has the greatest promise for rapid translation to the clinic and can realize quantitative visualization of biochemical processes in vivo. In this review, we will summarize the nuclear imaging probes utilized for predicting and evaluating the early anticancer therapy response.99mTc labeled agents and PET based radiopharmaceuticals like 18F-Paclitaxel, 11C-Verapamil for drug efflux pumps imaging will be discussed here. Moreover, molecular imaging probes used for targeted therapy response evaluation like 18F-Tamoxifen,89Zr-Trastuzumab will also be introduced in this review.

  5. Digital Image Analysis for Morphometric Evaluation of Tissue Response after Implanting Alloplastic Vascular Prostheses

    NASA Astrophysics Data System (ADS)

    Zippel, Roland; Hoene, Andreas; Walschus, Uwe; Jarchow, Raymond; Ueberrueck, Torsten; Patrzyk, Maciej; Schlosser, Michael; Wilhelm, Lutz

    2006-07-01

    The aim of this study was to examine the suitability of digital image analysis, using the KS400 software system, for the morphometric evaluation of the tissue response after prosthesis implantation in an animal model. Twenty-four female pigs aged 10 weeks were implanted with infrarenal Dacron® prostheses for 14, 21, 28, and 116 days. Following the explantation and investigation of the neointima region, the expression of beta-1-integrin, the proliferation rate by means of Ki-67 positive cells, and the intima thickness were evaluated as exemplary parameters of the tissue response after implantation. Frozen tissue sections were immunohistochemically stained and subsequently examined using computer-aided image analysis. A maximum expression of 32.9% was observed for beta-1-integrin 14 days after implantation, gradually declining over time to 9.8% after 116 days. The proliferation rate was found to be 19% on day 14, increasing to 39% on day 21 with a subsequent gradual decline to 5% after 116 days. The intima thickness increased from 189.9 [mu]m on day 14 to 1228.0 [mu]m on day 116. In conclusion, digital image analysis was found to be an efficient and reproducible method for the morphometric evaluation of a peri-prosthetic tissue response.

  6. The impact of the amount of social evaluation on psychobiological responses to a body image threat.

    PubMed

    Cloudt, Miranda C; Lamarche, Larkin; Gammage, Kimberley L

    2014-09-01

    The present study examined the impact of amount of social-evaluative body image threat on psychobiological responses. Women (N=123) were randomized into an individual-threat, group-threat or no-threat condition. Participants completed a measure of state body shame and provided a sample of saliva (to assess cortisol) at baseline and following their condition. Both threat conditions had higher baseline-adjusted body shame following the threat compared to the no-threat condition; however, no difference on baseline-adjusted body shame between the threat conditions was found. The same pattern of results was found for cortisol - both threat conditions had higher baseline-adjusted response cortisol than the no-threat condition, with no significant differences between the threat groups. Findings suggest that the magnitude of psychobiological responses to a social-evaluative body image threat does not differ with the amount of social-evaluative threat (individual- versus group-threat). These findings provide insight into the context of body image threats of women. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Application of spatial frequency response as a criterion for evaluating thermal imaging camera performance

    NASA Astrophysics Data System (ADS)

    Lock, Andrew; Amon, Francine

    2008-04-01

    Police, firefighters, and emergency medical personnel are examples of first responders that are utilizing thermal imaging cameras in a very practical way every day. However, few performance metrics have been developed to assist first responders in evaluating the performance of thermal imaging technology. This paper describes one possible metric for evaluating spatial resolution using an application of Spatial Frequency Response (SFR) calculations for thermal imaging. According to ISO 12233, the SFR is defined as the integrated area below the Modulation Transfer Function (MTF) curve derived from the discrete Fourier transform of a camera image representing a knife-edge target. This concept is modified slightly for use as a quantitative analysis of the camera's performance by integrating the area between the MTF curve and the camera's characteristic nonuniformity, or noise floor, determined at room temperature. The resulting value, which is termed the Effective SFR, can then be compared with a spatial resolution value obtained from human perception testing of task specific situations to determine the acceptability of the performance of thermal imaging cameras. The testing procedures described herein are being developed as part of a suite of tests for possible inclusion into a performance standard on thermal imaging cameras for first responders.

  8. Magnetic Resonance Imaging and Other Imaging Modalities in Diagnostic and Tumor Response Evaluation.

    PubMed

    Lambregts, Doenja M J; Maas, Monique; Stokkel, Marcel P M; Beets-Tan, Regina G H

    2016-07-01

    Functional imaging is emerging as a valuable contributor to the clinical management of patients with rectal cancer. Techniques such as diffusion-weighted magnetic resonance imaging, perfusion imaging, and positron emission tomography can offer meaningful insights into tissue architecture, vascularity, and metabolism. Moreover, new techniques targeting other aspects of tumor biology are now being developed and studied. This study reviews the potential role of functional imaging for the diagnosis, treatment monitoring, and assessment of prognosis in patients with rectal cancer.

  9. A framework for the analysis and evaluation of optical imaging systems with arbitrary response functions

    NASA Astrophysics Data System (ADS)

    Wang, Zhipeng

    The scientific applications and engineering aspects of multispectral and hyperspectral imaging systems have been studied extensively. The traditional geometric spectral imaging system model is specifically developed aiming at spectral sensors with spectrally non-overlapping bands. Spectral imaging systems with overlapping bands also exist. For example, the quantum-dot infrared photodetectors (QDIPs) for midwave- and longwave-infrared (IR) imaging systems exhibit highly overlapping spectral responses tunable through the bias voltages applied. This makes it possible to build spectrally tunable imaging system in IR range based on single QDIP. Furthermore, the QDIP based system can be operated as being adaptive to scenes. Other optical imaging systems like the human eye and some polarimetric sensing systems also have overlapping bands. To analyze such sensors, a functional analysis-based framework is provided in this dissertation. The framework starts from the mathematical description of the interaction between sensor and the radiation from scene reaching it. A geometric model of the spectral imaging process is provided based on the framework. The spectral response functions and the scene spectra are considered as vectors inside an 1-dimensional spectral space. The spectral imaging process is abstracted to represent a projection of scene spectrum onto sensor. The projected spectrum, which is the least-square error reconstruction of the scene vectors, contains the useful information for image processing. Spectral sensors with arbitrary spectral response functions are can be analyzed with this model. The framework leads directly to an image pre-processing algorithm to remove the data correlation between bands. Further discussion shows that this model can also serve the purpose of sensor evaluation, and thus facilitates comparison between different sensors. The spectral shapes and the Signal-to-Noise Ratios (SNR) of different bands are seen to influence the sensor

  10. Computer-assisted quantitative evaluation of therapeutic responses for lymphoma using serial PET/CT imaging.

    PubMed

    Gao, Xin; Xue, Zhong; Xing, Jiong; Lee, Daniel Y; Gottschalk, Stephen M; Heslop, Helen E; Bollard, Catherine M; Wong, Stephen T C

    2010-04-01

    Molecular imaging modalities such as positron emission tomography (PET)/computed tomography (CT) have emerged as an essential diagnostic tool for monitoring treatment response in lymphoma patients. However, quantitative assessment of treatment outcomes from serial scans is often difficult, laborious, and time consuming. Automatic quantization of longitudinal PET/CT scans provides more efficient and comprehensive quantitative evaluation of cancer therapeutic responses. This study develops and validates a Longitudinal Image Navigation and Analysis (LINA) system for this quantitative imaging application. LINA is designed to automatically construct longitudinal correspondence along serial images of individual patients for changes in tumor volume and metabolic activity via regions of interest (ROI) segmented from a given time point image and propagated into the space of all follow-up PET/CT images. We applied LINA retrospectively to nine lymphoma patients enrolled in an immunotherapy clinical trial conducted at the Center for Cell and Gene Therapy, Baylor College of Medicine. This methodology was compared to the readout by a diagnostic radiologist, who manually measured the ROI metabolic activity as defined by the maximal standardized uptake value (SUVmax). Quantitative results showed that the measured SUVs obtained from automatic mapping are as accurate as semiautomatic segmentation and consistent with clinical examination findings. The average of relative squared differences of SUVmax between automatic and semiautomatic segmentation was found to be 0.02. These data support a role for LINA in facilitating quantitative analysis of serial PET/CT images to efficiently assess cancer treatment responses in a comprehensive and intuitive software platform. Copyright 2010 AUR. Published by Elsevier Inc. All rights reserved.

  11. Brain tumor response to nimotuzumab treatment evaluated on magnetic resonance imaging.

    PubMed

    Dalmau, Evelio Rafael González; Cabal Mirabal, Carlos; Martínez, Giselle Saurez; Dávila, Agustín Lage; Suárez, José Carlos Ugarte; Cabanas Armada, Ricardo; Rodriguez Cruz, Gretel; Darias Zayas, Daniel; Castillo, Martha Ríos; Valle Garrido, Luis; Sotolongo, Luis Quevedo; Fernández, Mercedes Monzón

    2014-02-01

    Nimotuzumab, a humanized monoclonal antibody anti-epidermal growth factor receptor, has been shown to improve survival and quality of life in patients with pediatric malignant brain tumor. It is necessary, however, to increase the objective response criteria to define the optimal therapeutic schedule. The aim of this study was to obtain magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) quantitative information related to dimensions and morphology, molecular mobility and metabolic activity of the lesion and surroundings in order to evaluate any changes through time. Fourteen pediatric patients treated with nimotuzumab were evaluated on MRI and MRS for >2 years. Each patient was their own control. The MRI/MRS pulse sequence parameters were standardized to ensure experimental reproducibility. A total of 71.4% of patients had stable disease; 21.4% had objective response and 7.1% had progression of disease during the >2 year evaluation period. MRI/MRS data with clinical information provide a clearer picture of treatment response and confirm once again that nimotuzumab is effective in the treatment of pediatric brain tumor. These imaging procedures can be a useful tool for the clinical evaluation of study protocol in clinical practice. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

  12. Evaluation of chemotherapy response in ovarian cancer treatment using quantitative CT image biomarkers: a preliminary study

    NASA Astrophysics Data System (ADS)

    Qiu, Yuchen; Tan, Maxine; McMeekin, Scott; Thai, Theresa; Moore, Kathleen; Ding, Kai; Liu, Hong; Zheng, Bin

    2015-03-01

    The purpose of this study is to identify and apply quantitative image biomarkers for early prediction of the tumor response to the chemotherapy among the ovarian cancer patients participated in the clinical trials of testing new drugs. In the experiment, we retrospectively selected 30 cases from the patients who participated in Phase I clinical trials of new drug or drug agents for ovarian cancer treatment. Each case is composed of two sets of CT images acquired pre- and post-treatment (4-6 weeks after starting treatment). A computer-aided detection (CAD) scheme was developed to extract and analyze the quantitative image features of the metastatic tumors previously tracked by the radiologists using the standard Response Evaluation Criteria in Solid Tumors (RECIST) guideline. The CAD scheme first segmented 3-D tumor volumes from the background using a hybrid tumor segmentation scheme. Then, for each segmented tumor, CAD computed three quantitative image features including the change of tumor volume, tumor CT number (density) and density variance. The feature changes were calculated between the matched tumors tracked on the CT images acquired pre- and post-treatments. Finally, CAD predicted patient's 6-month progression-free survival (PFS) using a decision-tree based classifier. The performance of the CAD scheme was compared with the RECIST category. The result shows that the CAD scheme achieved a prediction accuracy of 76.7% (23/30 cases) with a Kappa coefficient of 0.493, which is significantly higher than the performance of RECIST prediction with a prediction accuracy and Kappa coefficient of 60% (17/30) and 0.062, respectively. This study demonstrated the feasibility of analyzing quantitative image features to improve the early predicting accuracy of the tumor response to the new testing drugs or therapeutic methods for the ovarian cancer patients.

  13. IMAGE-GUIDED EVALUATION AND MONITORING OF TREATMENT RESPONSE IN PATIENTS WITH DRY EYE DISEASE

    PubMed Central

    Hamrah, Pedram

    2014-01-01

    Dry eye disease (DED) is one of the most common ocular disorders worldwide. The pathophysiological mechanisms involved in the development of DED are not well understood and thus treating DED has been a significant challenge for ophthalmologists. Most of the currently available diagnostic tests demonstrate low correlation to patient symptoms and have low reproducibility. Recently, sophisticated in vivo imaging modalities have become available for patient care, namely, in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT). These emerging modalities are powerful and non-invasive, allowing real-time visualization of cellular and anatomical structures of the cornea and ocular surface. Here we discuss how, by providing both qualitative and quantitative assessment, these techniques can be used to demonstrate early subclinical disease, grade layer-by-layer severity, and allow monitoring of disease severity by cellular alterations. Imaging-guided stratification of patients may also be possible in conjunction with clinical examination methods. Visualization of subclinical changes and stratification of patients in vivo, allows objective image-guided evaluation of tailored treatment response based on cellular morphological alterations specific to each patient. This image-guided approach to DED may ultimately improve patient outcomes and allow studying the efficacy of novel therapies in clinical trials. PMID:24696045

  14. SU-E-QI-20: A Review of Advanced PET and CT Image Features for the Evaluation of Tumor Response

    SciTech Connect

    Lu, W

    2014-06-15

    Purpose: To review the literature in using quantitative PET and CT image features for the evaluation of tumor response. Methods: We reviewed and summarized more than fifty papers that use advanced, quantitative PET/CT image features for the evaluation of tumor response. We also discussed future works on extracting disease-specific features, combining multiple and complementary features in response modeling, delineating tumor in multimodality images, and exploring biological explanations of these advanced features. Results: Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features (characterizing spatial distribution of FDG uptake) have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Conclusions: Advanced, quantitative FDG PET/CT image features have been shown promising for the evaluation of tumor response. With the emerging multi-modality imaging performed at multiple time points for each patient, it becomes more important to analyze the serial images quantitatively, select and combine both complementary and contradictory information from various sources, for accurate and personalized evaluation of tumor response to therapy.

  15. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    SciTech Connect

    Lu, W; Wang, J; Zhang, H

    2015-06-15

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  16. Quantitative evaluation of breast cancer response to neoadjuvant chemotherapy by diffusion tensor imaging: Initial results.

    PubMed

    Furman-Haran, Edna; Nissan, Noam; Ricart-Selma, Verónica; Martinez-Rubio, Carmen; Degani, Hadassa; Camps-Herrero, Julia

    2017-09-13

    Diffusion tensor imaging (DTI) yields several parameters that have not been tested in response evaluation to neoadjuvant chemotherapy (NAC). To evaluate and compare in reference to histopathology findings the ability of DTI and dynamic contrast-enhanced (DCE) MRI to monitor response to NAC. Retrospective. Twenty patients treated with neoadjuvant chemotherapy. 1.5T MRI axial, bilateral T2 -weighted, DTI, and DCE-MRI. A standardized blinded image analysis at pixel resolution generated color-coded maps of DTI and DCE parameters STATISTICAL TESTS: Pearson's correlation analysis and Bland-Altman plots of the DTI and DCE size changes and of the pathological final residual tumor diameter and DCE or DTI final diameter, from pre- to post-NAC. Spearman coefficient of rank correlation between the DTI and DCE size changes from pre- to post-NAC and Miller and Payne (M&P) pathological response grading. Receiver operating characteristic curve analyses to differentiate between responders to nonresponders on the basis of the DTI and DCE percent size changes and the changes in DTI parameters. DTI and DCE changes in the cancers' diameter and volume from pre- to post-NAC exhibited high and significant Pearson correlation (r = 0.82 P = 1.2 × 10(-5) ). The DTI volume changes exhibited a significant Spearman coefficient rank correlation (0.68, P = 0.001) with the pathological M&P grading and differentiated between responders and nonresponders with area-under-the-curve (AUC) of 0.83 ± 0.10. A similar AUC for differentiating responders from nonresponders was exhibited by the changes in the highest diffusion coefficient (0.84 ± 0.11) and the mean diffusivity (0.83 ± 0.11). The DTI residual-tumor-diameter showed a high and significant Pearson correlation (r = 0.87 P = 1.2 × 10(-6) ) to pathology tumor diameter. DTI monitors changes in cancer size and diffusion tensor parameters in response to NAC with an accuracy equivalent to that of DCE, enabling

  17. Diffusion-Weighted MR Imaging of Hepatocellular Carcinoma: Current Value in Clinical Evaluation of Tumor Response to Locoregional Treatment.

    PubMed

    Yuan, Zheng; Zhang, Jian; Yang, Huan; Ye, Xiao-Dan; Xu, Li-Chao; Li, Wen-Tao

    2016-01-01

    The established size-based image biomarkers for tumor burden measurement continue to be applied to solid tumors, as size measurement can easily be used in clinical practice. However, in the setting of novel targeted therapies and liver-directed locoregional treatments for hepatocellular carcinoma (HCC), simple tumor anatomic changes can be less informative and usually appear later than biologic changes. Functional magnetic resonance (MR) imaging has the potential to be a promising technique for assessment of HCC response to therapy. Diffusion-weighted MR imaging is now widely used as a standard imaging modality to evaluate the liver. This review discusses the current clinical value of diffusion-weighted MR imaging in the evaluation of tumor response after nonsurgical locoregional treatment of HCC.

  18. Evaluation of Neoadjuvant Chemotherapy Response with Dynamic Contrast Enhanced Breast Magnetic Resonance Imaging in Locally Advanced Invasive Breast Cancer

    PubMed Central

    Gezer, Naciye Sinem; Orbay, Özge; Balcı, Pınar; Durak, Merih Guray; Demirkan, Binnaz; Saydam, Serdar

    2014-01-01

    Objective The reliability of traditional methods such as physical examination, ultrasonography (US) and mammography is limited in determining the type of treatment response in patients with neoadjuvant chemotherapy (NAC) application for locally advanced breast cancer (LABC). Dynamic contrast-enhanced magnetic resonance imaging (MRI) is gaining popularity in the evaluation of NAC response. This study aimed to compare NAC response as determined by dynamic contrast-enhanced breast MRI in patients with LABC to histopathology that is the gold standard; and evaluate the compatibility of MRI, mammography and US with response types. Materials and Methods The US, mammography and MRI findings of 38 patients who received NAC with a diagnosis of locally advanced breast cancer and surgical treatment were retrospectively analyzed and compared to histopathology results. Type of response to treatment was determined according to the “Criteria in Solid Tumors Response Evolution 1.1” by mammography, US and MRI criteria. The relationship between response types as defined by all three imaging modalities and histopathology were evaluated, and the correlation of response type as detected by MRI and pathological response and histopathological type of breast cancer was further determined. For statistical analysis, the chi-square, paired t test, correlation and kappa tests were used. Results There is a statistical moderate positive correlation between response type according to pathology and MRI (kappa: 0.63). There was a weak correlation between response type according to mammography or US and according to pathology (kappa: 0.2). When the distribution of treatment response by MRI is stratified according to histopathological types, partial response was higher in all histopathological types similar to the type of pathologic response. When compared with pathology MRI detected treatment response accurately in 84.2% of the patients. Conclusion Dynamic contrast-enhanced breast MRI appears to

  19. Colorectal cancer: Current imaging methods and future perspectives for the diagnosis, staging and therapeutic response evaluation

    PubMed Central

    Kekelidze, Maka; D’Errico, Luigia; Pansini, Michele; Tyndall, Anthony; Hohmann, Joachim

    2013-01-01

    In the last 10 years the mortality rate of colorectal cancer (CRC) has decreased by more than 20% due to the rising developments in diagnostic techniques and optimization of surgical, neoadjuvant and palliative therapies. Diagnostic methods currently used in the evaluation of CRC are heterogeneous and can vary within the countries and the institutions. This article aims to discuss in depth currently applied imaging modalities such as virtual computed tomography colonoscopy, endorectal ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of CRC. Special focus is put on the potential of recent diagnostic developments as diffusion weighted imaging MRI, MRI biomarkers (dynamic enhanced MRI), positron emission tomography with 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (FDG-PET) combined with computed tomography (PET/CT) and new hepatobiliary MRI contrast agents. The precise role, advantage and disadvantages of these modalities are evaluated controversially in local staging, metastatic spread and treatment monitoring of CRC. Finally, the authors will touch upon the future perspectives in functional imaging evaluating the role of integrated FDG-PET/CT with perfusion CT, MRI spectroscopy of primary CRC and hepatic transit time analysis using contrast enhanced ultrasound and MRI in the detection of liver metastases. Validation of these newer imaging techniques may lead to significant improvements in the management of patients with colorectal cancer. PMID:24379567

  20. A New Approach to Evaluate Drug Treatment Response of Ovarian Cancer Patients Based on Deformable Image Registration

    PubMed Central

    Tan, Maxine; Li, Zheng; Qiu, Yuchen; McMeekin, Scott D.; Thai, Theresa C.; Ding, Kai; Moore, Kathleen N.; Liu, Hong; Zheng, Bin

    2016-01-01

    Although Response Evaluation Criteria in Solid Tumors (RECIST) is the current clinical guideline to assess size change of solid tumors after therapeutic treatment, it has a relatively lower association to the clinical outcome of progression free survival (PFS) of the patients. In this paper, we presented a new approach to assess responses of ovarian cancer patients to new chemotherapy drugs in clinical trials. We first developed and applied a multi-resolution B-spline based deformable image registration method to register two sets of computed tomography (CT) image data acquired pre- and post-treatment. The B-spline difference maps generated from the co-registered CT images highlight the regions related to the volumetric growth or shrinkage of the metastatic tumors, and density changes related to variation of necrosis inside the solid tumors. Using a testing dataset involving 19 ovarian cancer patients, we compared patients’ response to the treatment using the new image registration method and RECIST guideline. The results demonstrated that using the image registration method yielded higher association with the six-month PFS outcomes of the patients than using RECIST. The image registration results also provided a solid foundation of developing new computerized quantitative image feature analysis schemes in the future studies. PMID:26336119

  1. Functional evaluation of hemodynamic response during neural activation using optical microangiography integrated with dual-wavelength laser speckle imaging

    PubMed Central

    Qin, Jia; Shi, Lei; Wang, Hequn; Reif, Roberto; Wang, Ruikang K.

    2014-01-01

    Abstract. Evaluation of spatiotemporal hemodynamic and metabolic responses during neural activation is crucial in studying brain function. We explore the use of a noninvasive multifunctional optical imaging system to measure these responses in a mouse brain upon electrically stimulated neural activation, with the cranium left intact. The system is developed by integrating an optical microangiography (OMAG) imaging system with a dual-wavelength laser speckle imaging (DW-LSI) system. The DW-LSI, running at an image acquisition speed of ∼100  Hz, is used to extract the large-scale two-dimensional map, revealing the localized response of blood flow, hemoglobin concentration, and metabolic rate of oxygen change. Guided by DW-LSI, the OMAG is, however, used to image the response of individual blood vessels with its unique depth-resolved capability. We show that the integrated system is capable of investigating neural activation, thus is potentially valuable in the preclinical study of the mechanism of neurovascular coupling. PMID:24549439

  2. The use of thermographic imaging to evaluate therapeutic response in human tumour xenograft models

    PubMed Central

    Hussain, Nosheen; Connah, David; Ugail, Hassan; Cooper, Patricia A.; Falconer, Robert A.; Patterson, Laurence H.; Shnyder, Steven D.

    2016-01-01

    Non-invasive methods to monitor tumour growth are an important goal in cancer drug development. Thermographic imaging systems offer potential in this area, since a change in temperature is known to be induced due to changes within the tumour microenvironment. This study demonstrates that this imaging modality can be applied to a broad range of tumour xenografts and also, for the first time, the methodology’s suitability to assess anti-cancer agent efficacy. Mice bearing subcutaneously implanted H460 lung cancer xenografts were treated with a novel vascular disrupting agent, ICT-2552, and the cytotoxin doxorubicin. The effects on tumour temperature were assessed using thermographic imaging over the first 6 hours post-administration and subsequently a further 7 days. For ICT-2552 a significant initial temperature drop was observed, whilst for both agents a significant temperature drop was seen compared to controls over the longer time period. Thus thermographic imaging can detect functional differences (manifesting as temperature reductions) in the tumour response to these anti-cancer agents compared to controls. Importantly, these effects can be detected in the first few hours following treatment and therefore the tumour is observable non-invasively. As discussed, this technique will have considerable 3Rs benefits in terms of reduction and refinement of animal use. PMID:27491535

  3. Evaluation of Treatment Associated Inflammatory Response on Diffusion Weighted-MRI and FDG-PET Imaging Biomarkers

    PubMed Central

    Galbán, Craig J.; Bhojani, Mahaveer S; Lee, Kuei C.; Meyer, Charles R.; Van Dort, Marcian; Kuszpit, Kyle; Koeppe, Robert A.; Ranga, Rajesh; Moffat, Bradford A.; Johnson, Timothy D.; Chenevert, Thomas L.; Rehemtulla, Alnawaz; Ross, Brian D.

    2010-01-01

    Purpose Functional imaging biomarkers of cancer treatment response offer the potential for early determination of outcome through assessment of biochemical, physiological, and micro-environmental readouts. Cell death may result in an immunological response thus complicating interpretation of biomarker readouts. This study evaluated the temporal impact of treatment-associated inflammatory activity on diffusion-MRI and FDG-PET imaging biomarkers to delineate the effects of the inflammatory response on imaging readouts. Experimental Design Rats with intracerebral 9L gliosarcomas were separated into four groups consisting of control, an immunosuppressive agent dexamethasone (Dex), 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), and BCNU+Dex (BCNU+Dex). Animals were imaged using diffusion-weighted MRI and FDG-PET at 0, 3 and 7 days post-treatment. Results In the BCNU and BCNU+Dex treated animal groups, diffusion values increased progressively over the 7 day study period to about 23% over baseline. FDG %SUV decreased at day 3 (−30.9%) but increased over baseline levels at day 7 (+20.1%). FDG-PET of BCNU+Dex treated animals were found to have %SUV reductions of −31.4% and −24.7% at days 3 and 7, respectively following treatment. Activated macrophages were observed on day 7 in the BCNU treatment group with much fewer found in the BCNU+Dex group. Conclusions Results revealed treatment-associated inflammatory response following tumor therapy resulted in accentuation of tumor diffusion response along with a corresponding increase in tumor FDG uptake due to the presence of glucose-consuming activated macrophages. The dynamics and magnitude of potential inflammatory response should be considered when interpreting imaging biomarker results. PMID:20160061

  4. Positron emission tomography in imaging evaluation of staging, restaging, treatment response, and prognosis in prostate cancer

    PubMed Central

    Jadvar, Hossein

    2017-01-01

    Prostate cancer is a prevalent public health problem worldwide. While imaging has played a major role in this disease, there still remain many challenges and opportunities. Positron emission tomography with various physiologically based radiotracers is fundamentally suited to interrogate this biologically and clinically heterogeneous disease along the course of its natural history. In this article, I review briefly the published evidence for the use of positron emission tomography with 18F-fluorodeoxyglucose, 11C-acetate, and 18F- or 11C-choline in the imaging evaluation of prostate cancer. Although the focus of the article will be on these radiotracers given the accumulated experience with them, but I will also comment on the outlook for the use of other emerging PET radiotracers such as those targeted to the prostate-specific membrane antigen and the amino acid metabolism pathway. It is anticipated that PET will play major role in the evaluation of prostate cancer in the current evidence-based medicine environment. There will also be exciting novel prospects for the use of therapeutic-diagnostic (theransotic) pairs in the management of patients with prostate cancer. PMID:27193789

  5. Evaluation of Soft Tissue Sarcoma Response to Preoperative Chemoradiotherapy Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

    PubMed Central

    Huang, Wei; Beckett, Brooke R.; Tudorica, Alina; Meyer, Janelle M.; Afzal, Aneela; Chen, Yiyi; Mansoor, Atiya; Hayden, James B.; Doung, Yee-Cheen; Hung, Arthur Y.; Holtorf, Megan L.; Aston, Torrie J.; Ryan, Christopher W.

    2016-01-01

    This study aims to assess the utility of quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters in comparison with imaging tumor size for early prediction and evaluation of soft tissue sarcoma response to preoperative chemoradiotherapy. In total, 20 patients with intermediate- to high-grade soft tissue sarcomas received either a phase I trial regimen of sorafenib + chemoradiotherapy (n = 8) or chemoradiotherapy only (n = 12), and underwent DCE-MRI at baseline, after 2 weeks of treatment with sorafenib or after the first chemotherapy cycle, and after therapy completion. MRI tumor size in the longest diameter (LD) was measured according to the RECIST (Response Evaluation Criteria In Solid Tumors) guidelines. Pharmacokinetic analyses of DCE-MRI data were performed using the Shutter-Speed model. After only 2 weeks of treatment with sorafenib or after 1 chemotherapy cycle, Ktrans (rate constant for plasma/interstitium contrast agent transfer) and its percent change were good early predictors of optimal versus suboptimal pathological response with univariate logistic regression C statistics values of 0.90 and 0.80, respectively, whereas RECIST LD percent change was only a fair predictor (C = 0.72). Post-therapy Ktrans, ve (extravascular and extracellular volume fraction), and kep (intravasation rate constant), not RECIST LD, were excellent (C > 0.90) markers of therapy response. Several DCE-MRI parameters before, during, and after therapy showed significant (P < .05) correlations with percent necrosis of resected tumor specimens. In conclusion, absolute values and percent changes of quantitative DCE-MRI parameters provide better early prediction and evaluation of the pathological response of soft tissue sarcoma to preoperative chemoradiotherapy than the conventional measurement of imaging tumor size change. PMID:28066805

  6. Responsive Image Inline Filter

    SciTech Connect

    Freeman, Ian

    2016-10-20

    RIIF is a contributed module for the Drupal php web application framework (drupal.org). It is written as a helper or sub-module of other code which is part of version 8 "core Drupal" and is intended to extend its functionality. It allows Drupal to resize images uploaded through the user-facing text editor within the Drupal GUI (a.k.a. "inline images") for various browser widths. This resizing is already done foe other images through the parent "Responsive Image" core module. This code extends that functionality to inline images.

  7. Evaluation of laser treatment response of vascular skin disorders in relation to skin properties using multi-spectral imaging

    NASA Astrophysics Data System (ADS)

    de Roode, Rowland; Noordmans, Herke Jan; Rem, Alex; Couwenberg, Sharon; Verdaasdonk, Rudolf

    2008-02-01

    There can be a large variation in response between laser treatments of vascular malformations like port-wine stains even in one patient. This could be ascribed to variations in the skin properties like tint (melanin) and perfusion (redness) which will influence the effectiveness of the laser dosimetry. To obtain a better understanding of the relation between skin properties just before treatment, laser dosimetry and clinical response, a multi-spectral dermatoscope is applied. A sequence of calibrated images is captured from 400 to 720 nm. Images at the treatment laser wavelength (532 nm) show the absorbing structures during laser exposure. Images of different treatment sessions of one patient were matched with dedicated registration software to quantify the results of the laser treatment (change in blood vessels structure, effect on pigment). For feasibility, images were collected from 5 patients and used to determine the optimal wavelength combination strategies. The image matching software gives an objective impression of the improvement, e.g. the clearing of the port-wine stain over time or pigment reactions, which will facilitate the discussion with the patient about the end point of treatment. The multi-spectral dermatoscope and software developed enables the evaluation of large patient series which will result in objective data to advise the dermatologist on the optimal laser dosimetry in future in relation to the skin properties.

  8. Evaluating the bending response of two osseointegrated transfemoral implant systems using 3D digital image correlation.

    PubMed

    Thompson, Melanie L; Backman, David; Branemark, Rickard; Mechefske, Chris K

    2011-05-01

    Osseointegrated transfemoral implants have been introduced as a prosthetic solution for above knee amputees. They have shown great promise, providing an alternative for individuals who could not be accommodated by conventional, socket-based prostheses; however, the occurrence of device failures is of concern. In an effort to improve the strength and longevity of the device, a new design has been proposed. This study investigates the mechanical behavior of the new taper-based assembly in comparison to the current hex-based connection for osseointegrated transfemoral implant systems. This was done to better understand the behavior of components under loading, in order to optimize the assembly specifications and improve the useful life of the system. Digital image correlation was used to measure surface strains on two assemblies during static loading in bending. This provided a means to measure deformation over the entire sample and identify critical locations as the assembly was subjected to a series of loading conditions. It provided a means to determine the effects of tightening specifications and connection geometry on the material response and mechanical behavior of the assemblies. Both osseoinegrated assemblies exhibited improved strength and mechanical performance when tightened to a level beyond the current specified tightening torque of 12 N m. This was shown by decreased strain concentration values and improved distribution of tensile strain. Increased tightening torque provides an improved connection between components regardless of design, leading to increased torque retention, decreased peak tensile strain values, and a more gradual, primarily compressive distribution of strains throughout the assembly.

  9. GOES-R Advanced Baseline Imager: spectral response functions and radiometric biases with the NPP Visible Infrared Imaging Radiometer Suite evaluated for desert calibration sites.

    PubMed

    Pearlman, Aaron; Pogorzala, David; Cao, Changyong

    2013-11-01

    The Advanced Baseline Imager (ABI), which will be launched in late 2015 on the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite R-series satellite, will be evaluated in terms of its data quality postlaunch through comparisons with other satellite sensors such as the recently launched Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership satellite. The ABI has completed much of its prelaunch characterization and its developers have generated and released its channel spectral response functions (response versus wavelength). Using these responses and constraining a radiative transfer model with ground reflectance, aerosol, and water vapor measurements, we simulate observed top of atmosphere (TOA) reflectances for analogous visible and near infrared channels of the VIIRS and ABI sensors at the Sonoran Desert and White Sands National Monument sites and calculate the radiometric biases and their uncertainties. We also calculate sensor TOA reflectances using aircraft hyperspectral data from the Airborne Visible/Infrared Imaging Spectrometer to validate the uncertainties in several of the ABI and VIIRS channels and discuss the potential for validating the others. Once on-orbit, calibration scientists can use these biases to ensure ABI data quality and consistency to support the numerical weather prediction community and other data users. They can also use the results for ABI or VIIRS anomaly detection and resolution.

  10. A B-spline image registration based CAD scheme to evaluate drug treatment response of ovarian cancer patients

    NASA Astrophysics Data System (ADS)

    Tan, Maxine; Li, Zheng; Moore, Kathleen; Thai, Theresa; Ding, Kai; Liu, Hong; Zheng, Bin

    2016-03-01

    Ovarian cancer is the second most common cancer amongst gynecologic malignancies, and has the highest death rate. Since the majority of ovarian cancer patients (>75%) are diagnosed in the advanced stage with tumor metastasis, chemotherapy is often required after surgery to remove the primary ovarian tumors. In order to quickly assess patient response to the chemotherapy in the clinical trials, two sets of CT examinations are taken pre- and post-therapy (e.g., after 6 weeks). Treatment efficacy is then evaluated based on Response Evaluation Criteria in Solid Tumors (RECIST) guideline, whereby tumor size is measured by the longest diameter on one CT image slice and only a subset of selected tumors are tracked. However, this criterion cannot fully represent the volumetric changes of the tumors and might miss potentially problematic unmarked tumors. Thus, we developed a new CAD approach to measure and analyze volumetric tumor growth/shrinkage using a cubic B-spline deformable image registration method. In this initial study, on 14 sets of pre- and post-treatment CT scans, we registered the two consecutive scans using cubic B-spline registration in a multiresolution (from coarse to fine) framework. We used Mattes mutual information metric as the similarity criterion and the L-BFGS-B optimizer. The results show that our method can quantify volumetric changes in the tumors more accurately than RECIST, and also detect (highlight) potentially problematic regions that were not originally targeted by radiologists. Despite the encouraging results of this preliminary study, further validation of scheme performance is required using large and diverse datasets in future.

  11. Program Evaluation Particularly Responsive Evaluation

    ERIC Educational Resources Information Center

    Stake, Robert E.

    2011-01-01

    In this paper, the author talks about some recent developments in the methodology of program evaluation and about what he calls "responsive evaluation." He discusses two models for program evaluation, namely (1) informal study or self-study; and (2) the pretest/posttest model. Then, he describes an approach that he has been working on, which will…

  12. Evaluator Responsiveness to Stakeholders

    ERIC Educational Resources Information Center

    Azzam, Tarek

    2010-01-01

    A simulation study was conducted in an attempt to examine how evaluators modify their evaluation design in response to differing stakeholder groups. In this study, evaluators were provided with a fictitious description of a school-based program. They were then asked to design an evaluation of the program. After the evaluation design decisions were…

  13. Evaluation of image quality

    NASA Technical Reports Server (NTRS)

    Pavel, M.

    1993-01-01

    This presentation outlines in viewgraph format a general approach to the evaluation of display system quality for aviation applications. This approach is based on the assumption that it is possible to develop a model of the display which captures most of the significant properties of the display. The display characteristics should include spatial and temporal resolution, intensity quantizing effects, spatial sampling, delays, etc. The model must be sufficiently well specified to permit generation of stimuli that simulate the output of the display system. The first step in the evaluation of display quality is an analysis of the tasks to be performed using the display. Thus, for example, if a display is used by a pilot during a final approach, the aesthetic aspects of the display may be less relevant than its dynamic characteristics. The opposite task requirements may apply to imaging systems used for displaying navigation charts. Thus, display quality is defined with regard to one or more tasks. Given a set of relevant tasks, there are many ways to approach display evaluation. The range of evaluation approaches includes visual inspection, rapid evaluation, part-task simulation, and full mission simulation. The work described is focused on two complementary approaches to rapid evaluation. The first approach is based on a model of the human visual system. A model of the human visual system is used to predict the performance of the selected tasks. The model-based evaluation approach permits very rapid and inexpensive evaluation of various design decisions. The second rapid evaluation approach employs specifically designed critical tests that embody many important characteristics of actual tasks. These are used in situations where a validated model is not available. These rapid evaluation tests are being implemented in a workstation environment.

  14. CRT image recording evaluation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Performance capabilities and limitations of a fiber optic coupled line scan CRT image recording system were investigated. The test program evaluated the following components: (1). P31 phosphor CRT with EMA faceplate; (2). P31 phosphor CRT with clear clad faceplate; (3). Type 7743 semi-gloss dry process positive print paper; (4). Type 777 flat finish dry process positive print paper; (5). Type 7842 dry process positive film; and (6). Type 1971 semi-gloss wet process positive print paper. Detailed test procedures used in each test are provided along with a description of each test, the test data, and an analysis of the results.

  15. Responsive Evaluation: An Interpretation.

    ERIC Educational Resources Information Center

    Lewy, Arieh

    1977-01-01

    Stake's concept of responsive evaluation is designed to provide various decision makers with the kind of information desired and in the form most helpful for making decisions. Compared with formal research procedures, this approach has both advantages and disadvantages. It may also provide a valuable supplement to formal evaluation. (CTM)

  16. Noninvasive In Vivo Imaging to Evaluate Immune Responses and Antimicrobial Therapy against Staphylococcus aureus and USA300 MRSA Skin Infections

    PubMed Central

    Cho, John S.; Zussman, Jamie; Donegan, Niles P.; Irene Ramos, Romela; Garcia, Nairy C.; Uslan, Daniel Z.; Iwakura, Yoichiro; Simon, Scott I.; Cheung, Ambrose L.; Modlin, Robert L.; Kim, Jenny; Miller, Lloyd S.

    2011-01-01

    Staphylococcus aureus skin infections represent a significant public health threat because of the emergence of antibiotic-resistant strains such as methicillin-resistant S. aureus (MRSA). As greater understanding of protective immune responses and more effective antimicrobial therapies are needed, a S. aureus skin wound infection model was developed in which full-thickness scalpel cuts on the backs of mice were infected with a bioluminescent S. aureus (methicillin sensitive) or USA300 community-acquired MRSA strain and in vivo imaging was used to noninvasively monitor the bacterial burden. In addition, the infection-induced inflammatory response was quantified using in vivo fluorescence imaging of LysEGFP mice. Using this model, we found that both IL-1α and IL-1β contributed to host defense during a wound infection, whereas IL-1β was more critical during an intradermal S. aureus infection. Furthermore, treatment of a USA300 MRSA skin infection with retapamulin ointment resulted in up to 85-fold reduction in bacterial burden and a 53% decrease in infection-induced inflammation. In contrast, mupirocin ointment had minimal clinical activity against this USA300 strain, resulting in only a 2-fold reduction in bacterial burden. Taken together, this S. aureus wound infection model provides a valuable preclinical screening method to investigate cutaneous immune responses and the efficacy of topical antimicrobial therapies. PMID:21191403

  17. Histological Evaluation of Prostate Tissue Response to Image-Guided Transurethral Thermal Therapy After a 48h Recovery Period

    NASA Astrophysics Data System (ADS)

    Boyes, Aaron; Tang, Kee; Chopra, Rajiv; Bronskill, Michael

    2009-04-01

    Image-guided transurethral ultrasound thermal therapy shows strong potential for sparing of critical adjacent structures during prostate cancer treatment. Preclinical experiments were conducted to provide further information on the extent of the treatment margin. Four experiments were carried out in a canine model to investigate the pathology of this margin during the early stages of recovery and were compared to previous results obtained immediately post-treatment. Sedated animals were placed in a 1.5T clinical MRI, and the heating device was positioned accurately within the prostatic urethra with image guidance. Using an MRI-compatible system, the ultrasound device was rotated 365° treating a prescribed volume contained within the gland. Quantitative temperature maps were acquired throughout the treatment, providing feedback information for device control. Animals were allowed to recover and, after 48h, an imaging protocol including T2 and contrast enhanced (CE) MRI was repeated before the animals were sacrificed. Prostate sections were stained with H&E. Careful slice alignment methods during histological procedures and image registration were employed to ensure good correspondence between MR images and microscopy. Although T2 MRI revealed no lesion acutely, a hypo-intense region was clearly visible 2 days post-treatment. The lesion volume defined by CE-MRI increased appreciably during this time. Whole-mount H&E sections showed that the margin between coagulated and normal-appearing cells narrowed during recovery, typically to a width of under 1mm compared to 3mm acutely. These results illustrate the high level of precision achievable with transurethral thermal therapy and suggest methods to monitor the physiological response non-invasively.

  18. An imaging-based platform for high-content, quantitative evaluation of therapeutic response in 3D tumour models

    NASA Astrophysics Data System (ADS)

    Celli, Jonathan P.; Rizvi, Imran; Blanden, Adam R.; Massodi, Iqbal; Glidden, Michael D.; Pogue, Brian W.; Hasan, Tayyaba

    2014-01-01

    While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls for reliable quantification of fluorescence signal. This streamlined methodology reads out the high density of information embedded in 3D culture systems, while maintaining a level of speed and efficiency traditionally achieved with global colorimetric reporters in order to facilitate broader implementation of 3D tumour models in therapeutic screening.

  19. An imaging-based platform for high-content, quantitative evaluation of therapeutic response in 3D tumour models.

    PubMed

    Celli, Jonathan P; Rizvi, Imran; Blanden, Adam R; Massodi, Iqbal; Glidden, Michael D; Pogue, Brian W; Hasan, Tayyaba

    2014-01-17

    While it is increasingly recognized that three-dimensional (3D) cell culture models recapitulate drug responses of human cancers with more fidelity than monolayer cultures, a lack of quantitative analysis methods limit their implementation for reliable and routine assessment of emerging therapies. Here, we introduce an approach based on computational analysis of fluorescence image data to provide high-content readouts of dose-dependent cytotoxicity, growth inhibition, treatment-induced architectural changes and size-dependent response in 3D tumour models. We demonstrate this approach in adherent 3D ovarian and pancreatic multiwell extracellular matrix tumour overlays subjected to a panel of clinically relevant cytotoxic modalities and appropriately designed controls for reliable quantification of fluorescence signal. This streamlined methodology reads out the high density of information embedded in 3D culture systems, while maintaining a level of speed and efficiency traditionally achieved with global colorimetric reporters in order to facilitate broader implementation of 3D tumour models in therapeutic screening.

  20. Ultrasonic Evaluation and Imaging

    SciTech Connect

    Crawford, Susan L.; Anderson, Michael T.; Diaz, Aaron A.; Larche, Michael R.; Prowant, Matthew S.; Cinson, Anthony D.

    2015-10-01

    Ultrasonic evaluation of materials for material characterization and flaw detection is as simple as manually moving a single-element probe across a speci-men and looking at an oscilloscope display in real time or as complex as automatically (under computer control) scanning a phased-array probe across a specimen and collecting encoded data for immediate or off-line data analyses. The reliability of the results in the second technique is greatly increased because of a higher density of measurements per scanned area and measurements that can be more precisely related to the specimen geometry. This chapter will briefly discuss applications of the collection of spatially encoded data and focus primarily on the off-line analyses in the form of data imaging. Pacific Northwest National Laboratory (PNNL) has been involved with as-sessing and advancing the reliability of inservice inspections of nuclear power plant components for over 35 years. Modern ultrasonic imaging techniques such as the synthetic aperture focusing technique (SAFT), phased-array (PA) technolo-gy and sound field mapping have undergone considerable improvements to effec-tively assess and better understand material constraints.

  1. Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment - Part 1

    PubMed Central

    Ramalho, Miguel; Matos, António P.; AlObaidy, Mamdoh; Velloni, Fernanda; Altun, Ersan; Semelka, Richard C.

    2017-01-01

    Magnetic resonance imaging (MRI) is the modern gold standard for the noninvasive evaluation of the cirrhotic liver. The combination of arterial phase hyperenhancement and delayed wash-out allows a definitive diagnosis of hepatocellular carcinoma (HCC) in patients with liver cirrhosis or chronic liver disease, without the requirement for confirmatory biopsy. That pattern is highly specific and has been endorsed in Western and Asian diagnostic guidelines. However, the sensitivity of the combination is relatively low for small HCCs. In this two-part review paper, we will address MRI of the cirrhotic liver. In this first part, we provide a brief background on liver cirrhosis and HCC, followed by descriptions of imaging surveillance of liver cirrhosis and the diagnostic performance of the different imaging modalities used in clinical settings. We then describe some of the requirements for the basic MRI technique, as well as the standard MRI protocol, and provide a detailed description of the appearance of various types of hepatocellular nodules encountered in the setting of the carcinogenic pathway in the cirrhotic liver, ranging from regenerative nodules to HCC. PMID:28298731

  2. SLI Thermal Imaging Requirements Evaluation

    NASA Astrophysics Data System (ADS)

    Hoffman, E. H.; Woody, L. M.; Wirth, S. M.; Smith, D. S.

    2015-12-01

    The Landsat program has provided a continuous record of global terrestrial imagery since 1972. This data record is an invaluable resource for determining long term trends and monitoring rates of change in land usage, forest health, water quality, and glacier retreat. In 2014, the National Aeronautics and Space Administration (NASA), supported by the United States Geological Survey (USGS), initiated the sustainable land imaging (SLI) architecture study to develop an affordable system design for acquiring future terrestrial imagery compatible with the existing Landsat data record. The principal objective has been to leverage recent advances in focal plane technologies to enable smaller, lower-cost instruments and launch options. We present an evaluation of the trade space implied by the SLI thermal imaging requirements as well as the performance potential of enabling technologies. Multiple approaches, each incorporating measured performance data for state-of-the-art detectors, are investigated to simultaneously optimize instrument mass and volume, spatial response, radiometric sensitivity, and radiometric uncertainty.

  3. Response evaluation of the neck in oropharyngeal cancer: Value of magnetic resonance imaging and influence of p16 in selecting patients for post-radiotherapy neck dissection.

    PubMed

    Lilja-Fischer, Jacob K; Jensen, Kenneth; Eskildsen, Helle W; Fink-Jensen, Vibeke; Nielsen, Viveque E

    2015-01-01

    Residual neck disease after radiotherapy in advanced oropharyngeal squamous cell carcinoma (OPSCC) is associated with increased mortality, and some patients may benefit from post-radiotherapy neck dissection (PRND). The aim of the present study was to assess the value of magnetic resonance imaging (MRI) and other clinical characteristics in selecting patients for PRND. Retrospective cohort study. Consecutive patients with N+ OPSCC were included. Medical records, pathology reports and imaging reports were reviewed. Pre- and post-therapeutic imaging was re-evaluated. A total of 100 consecutive patients from a three-year period were included. Neck response was evaluated with MRI two months after treatment. Sixty patients were suspicious for residual neck disease, and were offered surgery; seven of these patients had histologic evidence of carcinoma. Cumulative neck failure after three years was 14% (8.4-24%), and did not differ significantly among patients with positive compared to negative MRI (radiologist's initial description; p = 0.47, log-rank test). Applying neck failure as gold standard, sensitivity and specificity of MRI was 69% and 41%, respectively; positive and negative predictive value was 15% and 90%. Patients with p16 + disease had significantly larger lymph nodes after treatment, and imaging based on lymph node size resulted in many false positives. Analysis of receiver operating characteristic curves in 191 individual lymph nodes showed that a short axis ≥ 10 mm should be classified as suspicious. Furthermore, T-stage and p16-status were associated with increased risk of neck recurrence. Salvage was successful in four patients with early detected nodal recurrence. These results suggest that lymph node size, T-stage and p16 status could be used in selecting patients for PRND in OPSCC. Yet, early anatomical imaging may be inappropriate for evaluating neck response in patients with p16 + disease as enlarged lymph nodes often do not indicate residual

  4. Image recognition and consistency of response

    NASA Astrophysics Data System (ADS)

    Haygood, Tamara M.; Ryan, John; Liu, Qing Mary A.; Bassett, Roland; Brennan, Patrick C.

    2012-02-01

    Purpose: To investigate the connection between conscious recognition of an image previously encountered in an experimental setting and consistency of response to the experimental question.
    Materials and Methods: Twenty-four radiologists viewed 40 frontal chest radiographs and gave their opinion as to the position of a central venous catheter. One-to-three days later they again viewed 40 frontal chest radiographs and again gave their opinion as to the position of the central venous catheter. Half of the radiographs in the second set were repeated images from the first set and half were new. The radiologists were asked of each image whether it had been included in the first set. For this study, we are evaluating only the 20 repeated images. We used the Kruskal-Wallis test and Fisher's exact test to determine the relationship between conscious recognition of a previously interpreted image and consistency in interpretation of the image.
    Results. There was no significant correlation between recognition of the image and consistency in response regarding the position of the central venous catheter. In fact, there was a trend in the opposite direction, with radiologists being slightly more likely to give a consistent response with respect to images they did not recognize than with respect to those they did recognize.
    Conclusion: Radiologists' recognition of previously-encountered images in an observer-performance study does not noticeably color their interpretation on the second encounter.

  5. Body image inflexibility mediates the relationship between body image evaluation and maladaptive body image coping strategies.

    PubMed

    Mancuso, Serafino G

    2016-03-01

    Body image inflexibility, the unwillingness to experience negative appearance-related thoughts and emotions, is associated with negative body image and eating disorder symptoms. The present study investigated whether body image inflexibility mediated the relationship between body image evaluation and maladaptive body image coping strategies (appearance-fixing and experiential avoidance) in a college and community sample comprising 156 females aged 18-51 years (M=22.76, SD=6.96). Controlling for recruitment source (college vs. community), body image inflexibility fully mediated the relationship between body image evaluation and maladaptive body image coping strategies. Results indicated that an unwillingness to experience negative appearance-related thoughts and emotions is likely responsible for negative body image evaluation's relationship to appearance-fixing behaviours and experiential avoidance. Findings support extant evidence that interventions that explicitly target body image inflexibility, such as Acceptance and Commitment Therapy, may have utility in treating body dissatisfaction in nonclinical populations.

  6. Role of Dynamic Magnetic Resonance Imaging in the Evaluation of Tumor Response to Preoperative Concurrent Radiochemotherapy for Large Breast Cancers: A Prospective Phase II Study

    SciTech Connect

    Bollet, Marc A. Thibault, Fabienne; Bouillon, Kim; Meunier, Martine; Sigal-Zafrani, Brigitte; Savignoni, Alexia; Dieras, Veronique; Nos, Claude; Salmon, Remy; Fourquet, Alain

    2007-09-01

    Purpose: To evaluate the accuracy of clinical examination and of three imaging modalities (ultrasound [US] scan, mammography, and magnetic resonance imaging [MRI]) to assess the tumor response of breast cancer to a preoperative regimen of concurrent radiochemotherapy for large breast cancers, using pathologic data as the reference. Methods and Materials: Sixty women were accrued. Treatment consisted of 4 cycles of (5-fluorouracil-vinorelbine) chemotherapy with, starting with the second cycle of chemotherapy, locoregional radiotherapy to the breast and the internal mammary and supraclavicular and infraclavicular lymph nodes. Breast surgery and axillary lymph node dissection were subsequently performed. Breast imaging assessments were performed both before chemotherapy and preoperatively. Results: The correlation coefficients between tumor dimension at imaging and pathology were statistically significant for US scan (r = 0.4; p = 0.006) and MRI (r = 0.4; p = 0.004) but not for clinical examination (r 0.2; p = 0.16) or mammography (r = -0.15; p = 0.31). Furthermore, the area under the receiver operating characteristic curve for MRI was 0.81, compared with 0.67 for US scan. At the optimal threshold score, MRI performed with 81% sensitivity and 75% specificity. Conclusion: Compared with clinical examination, US scan, or mammography, MRI substantially improved the prediction of pathologic tumor response to preoperative concurrent radiochemotherapy for large breast cancers.

  7. Development of a single vial kit formulation of [99mTc]-labeled doxorubicin for tumor imaging and treatment response assessment-preclinical evaluation and preliminary human results.

    PubMed

    Kumar, Pardeep; Singh, Baljinder; Ghai, Anchal; Hazari, Puja P; Mittal, B R; Mishra, Anil K

    2015-05-30

    The present study describes the successful radiolabeling of [99mTcO(-) 4 ] with doxorubicin, and the resultant product was formulated in to a ready-to-label lyophilized single vial kit preparation for convenient use in a routine clinical setting. The radiolabeled preparation of [99mTc]-doxorubicin exhibited a high radiolabeling efficiency of more than 95.0%, serum stability for up to 24 h, and shelf-life of lyophilized cold kits was more than 6 months. Animal imaging data in tumor-bearing mice demonstrated that [99mTc]-doxorubicin accumulated in the tumor site with high target (tumor) to non-target (contra-lateral thigh) ratio (3.2 ± 0.5). The ratio decreased to 1.2 ± 0.6 indicating a good response on follow up imaging performed after 2 weeks of doxorubicin treatment. [99mTc]-doxorubicin scintigraphic data in human volunteers supported the hepato-renal excretion of the radiotracer as reflected by the increased accumulation of the radiotracer as a function of time in intestine, kidneys, and urinary bladder. Further, imaging in patients (very limited number) indicated that the technique may be useful in the detection of active sarcoma and post treatment (surgery/chemotherapy) remission or absence of the disease. The technique, however, needs validation through further preclinical evaluation and imaging in a larger number of patients. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Noninvasive imaging of immune responses

    PubMed Central

    Rashidian, Mohammad; Keliher, Edmund J.; Bilate, Angelina M.; Duarte, Joao N.; Wojtkiewicz, Gregory R.; Jacobsen, Johanne Tracey; Cragnolini, Juanjo; Swee, Lee Kim; Victora, Gabriel D.; Weissleder, Ralph; Ploegh, Hidde L.

    2015-01-01

    At their margins, tumors often contain neutrophils, dendritic cells, and activated macrophages, which express class II MHC and CD11b products. The interplay between stromal cells, tumor cells, and migratory cells such as lymphocytes creates opportunities for noninvasive imaging of immune responses. We developed alpaca-derived antibody fragments specific for mouse class II MHC and CD11b products, expressed on the surface of a variety of myeloid cells. We validated these reagents by flow cytometry and two-photon microscopy to obtain images at cellular resolution. To enable noninvasive imaging of the targeted cell populations, we developed a method to site-specifically label VHHs [the variable domain (VH) of a camelid heavy-chain only antibody] with 18F or 64Cu. Radiolabeled VHHs rapidly cleared the circulation (t1/2 ≈ 20 min) and clearly visualized lymphoid organs. We used VHHs to explore the possibility of imaging inflammation in both xenogeneic and syngeneic tumor models, which resulted in detection of tumors with remarkable specificity. We also imaged the infiltration of myeloid cells upon injection of complete Freund’s adjuvant. Both anti-class II MHC and anti-CD11b VHHs detected inflammation with excellent specificity. Given the ease of manufacture and labeling of VHHs, we believe that this method could transform the manner in which antitumor responses and/or infectious events may be tracked. PMID:25902531

  9. The Role of Diffusion-Weighted Magnetic Resonance Imaging in the Treatment Response Evaluation of Hepatocellular Carcinoma Patients Treated With Radiation Therapy

    SciTech Connect

    Yu, Jeong Il; Park, Hee Chul; Lim, Do Hoon; Choi, Yunseon; Jung, Sang Hoon; Paik, Seung Woon; Kim, Seong Hyun; Jeong, Woo Kyoung; Kim, Young Kon

    2014-07-15

    Purpose: We investigated the role of diffusion-weighted magnetic resonance imaging (DW MRI) as a response evaluation indicator for hepatocellular carcinoma (HCC) treated with radiation therapy (RT). Methods and Materials: Inclusion criteria of this retrospective study were DW MRI acquisition within 1 month before and 3 to 5 months after RT. In total, 48 patients were enrolled. Two radiation oncologists measured the apparent diffusion coefficient (ADC). Possible predictive factors, including alteration of the ADC value before and 3 to 5 month after RT, in relation to local progression-free survival (LPFS) were analyzed and compared. Results: Three months after RT, 6 patients (12.5%) showed a complete response, and 27 patients (56.3%) showed a partial response when evaluated using the modified response evaluation criteria in solid tumors (mRECIST). The average ADC ± SD values were 1.21 ± 0.27 ( × 10{sup −3} mm{sup 2}/s) before and 1.41 ± 0.36 ( × 10{sup −3} mm{sup 2}/s) after RT (P<.001). The most significant prognostic factor related to LPFS was mRECIST (P<.001). The increment of ADC value (≥20%) was also a significant factor (P=.02), but RECIST (version 1.1; P=.11) was not. When RECIST was combined with the increment of ADC value (≥20%), the LPFS rates were significantly different between the groups (P=.004), and the area under the curve value (0.745) was comparable with that of mRECIST (0.765). Conclusions: ADC value change before and after RT in HCC was closely related to LPFS. ADC value and RECIST may substitute for mRECIST in patients who cannot receive contrast agents.

  10. Systematic review of the value of ultrasound and magnetic resonance musculoskeletal imaging in the evaluation of response to treatment of gout.

    PubMed

    Villaverde, Virginia; Rosario, María Piedad; Loza, Estíbaliz; Pérez, Fernando

    2014-01-01

    Imaging may be useful for monitoring response to therapy. Within the OMERACT proposal for the core set domains for outcome measures in chronic gout, serum urate levels, recurrence of gouty flares, tophus regression, and joint damage imaging have been included, among other proposed issues. To perform a systematic literature review of the usefulness of magnetic resonance imaging (MRI) and ultrasound (US) on assessment of treatment response in patients with gout. MEDLINE, EMBASE, Cochrane Library (up to February 2012), and abstracts presented at the 2010 and 2011 meetings of the American College of Rheumatology and European League Against Rheumatism, were searched for treatment studies of any duration and therapeutic options, examining the ability of MRI/US to assess treatment response in gouty patients. Meta-analyses, systematic reviews, randomized clinical trials, cohort and case-control studies and validation studies were included. Quality was appraised using validated scales. There were only 3 US published studies in the literature that analysed US utility on assessment of response to treatment in patients with gout. All of them were prospective case studies with a small number of patients and they were reviewed in detailed. A total of 36 patients with gout were examined with US. All of them had a baseline serum urate >6mg/dL. US features of gout (double contour sign, hyperechoic spots in synovial fluid, hyperechoic cloudy areas, tophus diameter and volume) achieved significant reduction in patients who reached the objective of uricemia ≤6mg/dL in all the studies; however, patients in whom levels did not drop below 6mg/dL had no change of US features of gout. Other parameters evaluated in one study included ESR, CRP, number of tender joints (TRN), number of swollen joints, and pain score (SP). All of them decreased with uricemia reduction, but only TRN and SP were statistically significant. No data was found on the value of MRI on treatment response assessment

  11. Combined modalities of magnetic resonance imaging, endoscopy and computed tomography in the evaluation of tumor responses to definitive chemoradiotherapy in esophageal squamous cell carcinoma.

    PubMed

    Qiu, Bo; Wang, DeLing; Yang, Hong; Xie, WeiHao; Liang, Ying; Cai, Peiqiang; Chen, ZhaoLin; Liu, MengZhong; Fu, JianHua; Xie, ChuanMiao; Liu, Hui

    2016-11-01

    To explore the value of combined modalities, including anatomical and functional magnetic resonance imaging (MRI), endoscopy and computed tomography (CT), for the assessment of tumor responses to definitive chemoradiotherapy (dCRT) in esophageal squamous cell carcinoma (ESCC). Sixty-seven patients with locally advanced ESCC were enrolled. Tumor response (TR) was assessed two months after the completion of dCRT. Evaluation criteria according to combined modalities, including MRI, endoscopy and CT, were established and compared with traditional criteria based on CT and endoscopy. Progression-free survival (PFS)⩾12months was used as the reference standard, and the accuracy of the two criteria in response assessment was analyzed. Thirty-seven (55.2%) and 10 (14.9%) patients were considered to exhibit CR, as assessed by combined modalities and the traditional criteria, respectively. Using PFS⩾12months as a surrogate for CR, the sensitivity and specificity of the combined modalities were 82.4% and 88.9%, respectively, compared with 20.6% and 92.6% for the traditional criteria. TR assessed by combined modalities (CR vs. non-CR) was prognostic of PFS in univariate and multivariate analyses (Log-rank, P<0.0001; Cox regression, HR=0.114, 95% CI 0.048-0.272). Tumor responses assessed by the combined modalities of MR, endoscopy and CT seemed highly predictive of prognosis after dCRT in ESCC patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Evaluating vendor responses.

    PubMed

    Williams, F L; Tucker, S R

    1982-05-01

    The process of evaluating computer vendors' responses to a request for proposal (RFP) is described. The steps involved are (1) reviewing vendor proposals, (2) attending vendor presentations (3) reviewing references, (4) visiting vendor clients, (5) reviewing vendor stability, and (6) making the decision. The primary purpose of reviewing proposals is to reduce the number of vendors under consideration. Vendors' proposals should be attended by representatives of all affected departments, and each vendor's presentation should be discussed with the RFP or RFP extension as a guide. Interviewing users of a system helps determine how the system works in practice and how accurately the vendor has represented his product. Likewise, visiting selective vendor clients, without the vendor representative being present, helps establish whether the persons actually using the system like it and find it easy to use. A vendor's stability can be best determined by examining its financial stability and its commitment to the pharmacy product. Making the selection requires elimination of vendors that do not meet minimum requirements, rating the remaining vendors numerically, and deciding which features of each system are most desirable. The vendor selection process provides an opportunity to thoroughly study an operation and helps set priorities for the department.

  13. Predictive and prognostic value of FDG-PET/CT imaging and different response evaluation criteria after primary systemic therapy of breast cancer.

    PubMed

    Tőkés, Tímea; Kajáry, Kornélia; Szentmártoni, Gyöngyvér; Lengyel, Zsolt; Györke, Tamás; Torgyík, László; Somlai, Krisztián; Tőkés, Anna-Mária; Kulka, Janina; Dank, Magdolna

    2017-01-01

    (1) To predict pathological complete remission (pCR) and survival after primary systemic therapy (PST) in patients diagnosed with breast cancer by using two different PET/CT based scores: a simplified PERCIST-based PET/CT score (Method 1) and a combined PET/CT score supplemented with the morphological results of the RECIST system (Method 2) and (2) to assess the effect of different breast carcinoma subtypes on tumor response and its evaluation. Eighty-eight patients were enrolled in the study who underwent PET/CT imaging before and after PST. PET/CTs were evaluated by changes in maximum Standardized Uptake Value (SUVmax) and tumor size. Method 1 and 2 were applied to predict pathological complete remission (pCR). Kaplan-Meier analyses for survival were performed. Classification into biological subtypes was performed based on the pre-therapeutic tumor characteristics. A total of 30/88 patients showed pCR (34.1 %). Comparing pCR/non-pCR patient groups, significant differences were detected by changes in SUVmax (p < 0.001) and tumor size (p < 0.001) regarding the primary breast lesions. To predict pCR, Method 2 had higher sensitivity (72.4 % vs. 44.8 %) and negative predictive value (57.9 % vs. 45.8 %) with lower false negativity rate (16 vs. 32) than Method 1. pCR rate was higher in Her2-positive and triple negative tumors. Despite the significant differences detected between the biological subtypes regarding changes in primary tumor SUVmax (p = 0.007) and size (p = 0.015), the subtypes only had significant impact on response evaluation with Method 2 and not with Method 1. In our study, neither clinical nor pathological CR were predictors of longer progression-free survival. Our results suggest that combined PET/CT criteria are more predictive of pCR. The effect of biological subtypes is significant on pCR rate as well as on the changes in FDG-uptake and morphological tumor response. Response evaluation with combined criteria was also able to reflect the

  14. Evaluation of the utility of vibration response imaging device and Operation Planning Software in the assessment of patients before lung resection surgery.

    PubMed

    Jimenez, Unai; Marina, Nuria; de Santamaria, Elena Lopez; Pac, Joaquin Jose; Galdiz, Juan B

    2010-05-01

    A variety of methods have been used to evaluate patients with lung cancer to define a patient cohort at high risk for postoperative mortality and respiratory complications associated with lung resection surgery. Our aim was to evaluate the utility of vibration response imaging (VRI(XP)) Operation Planning Software (O-Plan) in assessing suitability for surgical resection and for the prediction of postoperative forced expiratory volume in 1s (ppoFEV(1)). A total of 58 subjects with lung cancer underwent evaluation prior to lung resection surgery and postoperative lung function after surgery. Preoperative pulmonary function tests and quantitative breath sound measurements by VRI were performed in all patients to estimate postoperative lung function. In addition, 20 patients underwent perfusion scan prior to surgery. VRI(XP) O-Plan predictions (12 pneumonectomies and 46 lobectomies) showed good correlation and concordance (Lin's coefficient) with postoperative FEV(1) (l) (r=0.865, Lin's coefficient 0.858) and FEV(1) (%) (r=0.877, Lin's coefficient 0.861) 4-6 weeks after surgery. Predicted and postoperative measured FEV(1) showed no significant differences (p>0.05). Average lung function predicted postoperative values were similar for perfusion and VRI(XP) O-Plan calculations with a correlation of 0.74 and concordance of 0.700. VRI(XP) O-Plan has shown high accuracy in predicting postoperative FEV(1) after lung resection surgery. Given its simplicity of operation and the non-invasive nature of VRI(XP) and O-Plan, it could be a good alternative to perfusion scan in pre-surgery assessment. Copyright 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

  15. Infrared image quality evaluation method without reference image

    NASA Astrophysics Data System (ADS)

    Yue, Song; Ren, Tingting; Wang, Chengsheng; Lei, Bo; Zhang, Zhijie

    2013-09-01

    Since infrared image quality depends on many factors such as optical performance and electrical noise of thermal imager, image quality evaluation becomes an important issue which can conduce to both image processing afterward and capability improving of thermal imager. There are two ways of infrared image quality evaluation, with or without reference image. For real-time thermal image, the method without reference image is preferred because it is difficult to get a standard image. Although there are various kinds of methods for evaluation, there is no general metric for image quality evaluation. This paper introduces a novel method to evaluate infrared image without reference image from five aspects: noise, clarity, information volume and levels, information in frequency domain and the capability of automatic target recognition. Generally, the basic image quality is obtained from the first four aspects, and the quality of target is acquired from the last aspect. The proposed method is tested on several infrared images captured by different thermal imagers. Calculate the indicators and compare with human vision results. The evaluation shows that this method successfully describes the characteristics of infrared image and the result is consistent with human vision system.

  16. The Evaluator's Responsibility for Utilization.

    ERIC Educational Resources Information Center

    Patton, Michael Quinn

    1988-01-01

    The role of the evaluator in insuring utilization and quality of evaluation results is discussed. Topics covered include a utilization-focused vision of accountability, overcoming staff fears of evaluation, eliciting the right information from users, situational responsiveness, and advocacy. (TJH)

  17. Online Course Evaluations Response Rates

    ERIC Educational Resources Information Center

    Guder, Faruk; Malliaris, Mary

    2013-01-01

    This paper studies the reasons for low response rates in online evaluations. Survey data are collected from the students to understand factors that might affect student participation in the course evaluation process. When course evaluations were opened to the student body, an email announcement was sent to all students, and a reminder email was…

  18. Referenceless image quality evaluation for whole slide imaging

    PubMed Central

    Hashimoto, Noriaki; Bautista, Pinky A.; Yamaguchi, Masahiro; Ohyama, Nagaaki; Yagi, Yukako

    2012-01-01

    Objective: The image quality in whole slide imaging (WSI) is one of the most important issues for the practical use of WSI scanners. In this paper, we proposed an image quality evaluation method for scanned slide images in which no reference image is required. Methods: While most of the conventional methods for no-reference evaluation only deal with one image degradation at a time, the proposed method is capable of assessing both blur and noise by using an evaluation index which is calculated using the sharpness and noise information of the images in a given training data set by linear regression analysis. The linear regression coefficients can be determined in two ways depending on the purpose of the evaluation. For objective quality evaluation, the coefficients are determined using a reference image with mean square error as the objective value in the analysis. On the other hand, for subjective quality evaluation, the subjective scores given by human observers are used as the objective values in the analysis. The predictive linear regression models for the objective and subjective image quality evaluations, which were constructed using training images, were then used on test data wherein the calculated objective values are construed as the evaluation indices. Results: The results of our experiments confirmed the effectiveness of the proposed image quality evaluation method in both objective and subjective image quality measurements. Finally, we demonstrated the application of the proposed evaluation method to the WSI image quality assessment and automatic rescanning in the WSI scanner. PMID:22530177

  19. Evaluation of a Simplified Intravoxel Incoherent Motion (IVIM) Analysis of Diffusion-Weighted Imaging for Prediction of Tumor Size Changes and Imaging Response in Breast Cancer Liver Metastases Undergoing Radioembolization: A Retrospective Single Center Analysis.

    PubMed

    Pieper, Claus C; Sprinkart, Alois M; Meyer, Carsten; König, Roy; Schild, Hans H; Kukuk, Guido M; Mürtz, Petra

    2016-04-01

    To investigate the value of a simplified intravoxel incoherent motion (IVIM) analysis for evaluation of therapy-induced tumor changes and response of breast cancer liver metastases (mBRC) undergoing radioembolization.In 21 females (mean age 54 years, range 43-72) with mBRC tumor size changes and response evaluation criteria in solid tumors (RECIST) response to 26 primary radioembolization procedures were analyzed. Standard 1.5-T liver magnetic resonance imaging including respiratory-gated diffusion-weighted imaging (DWI) with b0 = 0 s/mm, b1 = 50 s/mm, b2 = 800 s/mm before and 6 weeks after each treatment was performed. In addition to the apparent diffusion coefficient (ADC)(0,800), the estimated diffusion coefficient D' and the perfusion fraction f' were determined using a simplified IVIM approach. For each radioembolization, the 2 largest treated metastases (if available) were analyzed. Lesions were categorized according to size changes into group A (reduction of longest diameter [LD]) and group B (LD increase) after 3 months. Radioembolization procedures were further categorized into "response" (partial response and stable disease) and "nonresponse" (progressive disease) according to RECIST after 3 months. ADC and D' are given in 10 mm/s.Forty-five metastases were analyzed. Thirty-two lesions were categorized as A; 13 as B. Before therapy, group A lesions showed significantly larger f'-values than B (P = 0.001), but ADC(0,800) and D' did not differ. After therapy, in group A lesions the ADC(0,800)- and D'-values increased and f' decreased (P < 0.0001); in contrast in group B lesions f' increased (P = 0.001). Groups could be differentiated by preinterventional f' and by changes of D' and f' between pre and postinterventional imaging (area under the curve [AUC] of 0.903, 0.747 and 1.0, respectively).Preinterventional parameters did not differ between responders and nonresponders according to RECIST. ADC(0,800)- and D'-values showed a

  20. EVALUATING HYDROLOGICAL RESPONSE TO ...

    EPA Pesticide Factsheets

    Studies of future management and policy options based on different assumptions provide a mechanism to examine possible outcomes and especially their likely benefits or consequences. Planning and assessment in land and water resource management are evolving toward complex, spatially explicit regional assessments. These problems have to be addressed with distributed models that can compute runoff and erosion at different spatial and temporal scales. The extensive data requirements and the difficult task of building input parameter files, however, have long been an obstacle to the timely and cost-effective use of such complex models by resource managers. The U.S. EPA Landscape Ecology Branch in collaboration with the USDA-ARS Southwest Watershed Research Center has developed a geographic information system (GIS) tool to facilitate this process. A GIS provides the framework within which spatially distributed data are collected and used to prepare model input files, and model results are evaluated. The Automated Geospatial Watershed Assessment (AGWA) tool uses widely available standardized spatial datasets that can be obtained via the internet at no cost to the user. The data are used to develop input parameter files for KINEROS2 and SWAT, two watershed runoff and erosion simulation models that operate at different spatial and temporal scales. AGWA automates the process of transforming digital data into simulation model results and provides a visualization tool

  1. [A method of iris image quality evaluation].

    PubMed

    Murat, Hamit; Mao, Dawei; Tong, Qinye

    2006-04-01

    Iris image quality evaluation plays a very important part in iris computer recognition. An iris image quality evaluation method was introduced into this study to distinguish good image from bad image caused by pupil distortion, blurred boundary, two circles appearing not concentric, and severe occlusion by eyelids and eyelashes. The tests based on this method gave good results.

  2. Evaluation of a Simplified Intravoxel Incoherent Motion (IVIM) Analysis of Diffusion-Weighted Imaging for Prediction of Tumor Size Changes and Imaging Response in Breast Cancer Liver Metastases Undergoing Radioembolization

    PubMed Central

    Pieper, Claus C.; Sprinkart, Alois M.; Meyer, Carsten; König, Roy; Schild, Hans H.; Kukuk, Guido M.; Mürtz, Petra

    2016-01-01

    Abstract To investigate the value of a simplified intravoxel incoherent motion (IVIM) analysis for evaluation of therapy-induced tumor changes and response of breast cancer liver metastases (mBRC) undergoing radioembolization. In 21 females (mean age 54 years, range 43–72) with mBRC tumor size changes and response evaluation criteria in solid tumors (RECIST) response to 26 primary radioembolization procedures were analyzed. Standard 1.5-T liver magnetic resonance imaging including respiratory-gated diffusion-weighted imaging (DWI) with b0 = 0 s/mm2, b1 = 50 s/mm2, b2 = 800 s/mm2 before and 6 weeks after each treatment was performed. In addition to the apparent diffusion coefficient (ADC)(0,800), the estimated diffusion coefficient D′ and the perfusion fraction f′ were determined using a simplified IVIM approach. For each radioembolization, the 2 largest treated metastases (if available) were analyzed. Lesions were categorized according to size changes into group A (reduction of longest diameter [LD]) and group B (LD increase) after 3 months. Radioembolization procedures were further categorized into “response” (partial response and stable disease) and “nonresponse” (progressive disease) according to RECIST after 3 months. ADC and D′ are given in 10−6 mm2/s. Forty-five metastases were analyzed. Thirty-two lesions were categorized as A; 13 as B. Before therapy, group A lesions showed significantly larger f′-values than B (P = 0.001), but ADC(0,800) and D′ did not differ. After therapy, in group A lesions the ADC(0,800)- and D′-values increased and f′ decreased (P < 0.0001); in contrast in group B lesions f′ increased (P = 0.001). Groups could be differentiated by preinterventional f′ and by changes of D′ and f′ between pre and postinterventional imaging (area under the curve [AUC] of 0.903, 0.747 and 1.0, respectively). Preinterventional parameters did not differ between responders and nonresponders

  3. Evaluation of Magnetic Resonance Imaging Responsiveness in Active Psoriatic Arthritis at Multiple Timepoints during the First 12 Weeks of Antitumor Necrosis Factor Therapy.

    PubMed

    Feletar, Marie; Hall, Stephen; Bird, Paul

    2016-01-01

    To assess the responsiveness of high- and low-field extremity magnetic resonance imaging (MRI) variables at multiple timepoints in the first 12 weeks post-antitumor necrosis factor (anti-TNF) therapy initiation in patients with psoriatic arthritis (PsA) and active dactylitis. Twelve patients with active PsA and clinical evidence of dactylitis involving at least 1 digit were recruited. Patients underwent sequential high-field conventional (1.5 Tesla) and extremity low-field MRI (0.2 Tesla) of the affected hand or foot, pre- and postgadolinium at baseline (pre-TNF), 2 weeks (post-TNF), 6 weeks, and 12 weeks. A blinded observer scored all images on 2 occasions using the PsA MRI scoring system. Eleven patients completed the study, but only 6 patients completed all high-field and low-field MRI assessments. MRI scores demonstrated rapid response to TNF inhibition with score reduction in tenosynovitis, synovitis, and osteitis at 2 weeks. Intraobserver reliability was good to excellent for all variables. High-field MRI demonstrated greater sensitivity to tenosynovitis, synovitis, and osteitis and greater responsiveness to change posttreatment. Treatment responses were maintained to 12 weeks. This study demonstrates the use of MRI in detecting early response to biologic therapy. MRI variables of tenosynovitis, synovitis, and osteitis demonstrated responsiveness posttherapy with high-field scores more responsive to change than low-field scores.

  4. Information Science and Responsive Evaluation

    ERIC Educational Resources Information Center

    Stake, Robert E.

    2014-01-01

    Responsive evaluation builds upon the methods of informal evaluation in disciplined ways: getting personally acquainted with the evaluand, observation of activities, interviewing people who are in different ways familiar with the evaluand, searching documents that reveal what happened in the past or somewhere else. It calls for sustained effort to…

  5. Information Science and Responsive Evaluation

    ERIC Educational Resources Information Center

    Stake, Robert E.

    2014-01-01

    Responsive evaluation builds upon the methods of informal evaluation in disciplined ways: getting personally acquainted with the evaluand, observation of activities, interviewing people who are in different ways familiar with the evaluand, searching documents that reveal what happened in the past or somewhere else. It calls for sustained effort to…

  6. Vibration response imaging: a novel noninvasive tool for evaluating the initial therapeutic effect of noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease

    PubMed Central

    2012-01-01

    Background The popular methods for evaluating the initial therapeutic effect (ITE) of noninvasive positive pressure ventilation (NPPV) can only roughly reflect the therapeutic outcome of a patient’s ventilation because they are subjective, invasive and time-delayed. In contrast, vibration response imaging (VRI) can monitor the function of a patient’s ventilation over the NPPV therapy in a non-invasive manner. This study aimed to investigate the value of VRI in evaluating the ITE of NPPV for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods Thirty-six AECOPD patients received VRI at three time points: before NPPV treatment (T1), at 15 min of NPPV treatment (T2), and at 15 min after the end of NPPV treatment (T4). Blood gas analysis was also performed at T1 and at 2 hours of NPPV treatment (T3). Thirty-nine healthy volunteers also received VRI at T1 and T2. VRI examination at the time point T2 in either the patients or volunteers did not require any interruption of the on-going NPPV. The clinical indices at each time point were compared between the two groups. Moreover, correlations between the PaCO2 changes (T3 vs T1) and abnormal VRI scores (AVRIS) changes (T2 vs T1) were analyzed. Results No significant AVRIS differences were found between T1 and T2 in the healthy controls (8.51 ± 3.36 vs. 8.53 ± 3.57, P > 0.05). The AVRIS, dynamic score, MEF score and EVP score showed a significant decrease in AECOPD patients at T2 compared with T1 (P < 0.05), but a significant increase at T4 compared with T2 (P < 0.05). We also found a positive correlation (R2 = 0.6399) between the PaCO2 changes (T3 vs T1) and AVRIS changes (T2 vs T1). Conclusions VRI is a promising noninvasive tool for evaluating the initial therapeutic effects of NPPV in AECOPD patients and predicting the success of NPPV in the early stage. PMID:22856613

  7. Recommendations for imaging tumor response in neurofibromatosis clinical trials

    PubMed Central

    Ardern-Holmes, Simone L.; Babovic-Vuksanovic, Dusica; Barker, Fred G.; Connor, Steve; Evans, D. Gareth; Fisher, Michael J.; Goutagny, Stephane; Harris, Gordon J.; Jaramillo, Diego; Karajannis, Matthias A.; Korf, Bruce R.; Mautner, Victor; Plotkin, Scott R.; Poussaint, Tina Y.; Robertson, Kent; Shih, Chie-Schin; Widemann, Brigitte C.

    2013-01-01

    Objective: Neurofibromatosis (NF)-related benign tumors such as plexiform neurofibromas (PN) and vestibular schwannomas (VS) can cause substantial morbidity. Clinical trials directed at these tumors have become available. Due to differences in disease manifestations and the natural history of NF-related tumors, response criteria used for solid cancers (1-dimensional/RECIST [Response Evaluation Criteria in Solid Tumors] and bidimensional/World Health Organization) have limited applicability. No standardized response criteria for benign NF tumors exist. The goal of the Tumor Measurement Working Group of the REiNS (Response Evaluation in Neurofibromatosis and Schwannomatosis) committee is to propose consensus guidelines for the evaluation of imaging response in clinical trials for NF tumors. Methods: Currently used imaging endpoints, designs of NF clinical trials, and knowledge of the natural history of NF-related tumors, in particular PN and VS, were reviewed. Consensus recommendations for response evaluation for future studies were developed based on this review and the expertise of group members. Results: MRI with volumetric analysis is recommended to sensitively and reproducibly evaluate changes in tumor size in clinical trials. Volumetric analysis requires adherence to specific imaging recommendations. A 20% volume change was chosen to indicate a decrease or increase in tumor size. Use of these criteria in future trials will enable meaningful comparison of results across studies. Conclusions: The proposed imaging response evaluation guidelines, along with validated clinical outcome measures, will maximize the ability to identify potentially active agents for patients with NF and benign tumors. PMID:24249804

  8. Recommendations for imaging tumor response in neurofibromatosis clinical trials.

    PubMed

    Dombi, Eva; Ardern-Holmes, Simone L; Babovic-Vuksanovic, Dusica; Barker, Fred G; Connor, Steve; Evans, D Gareth; Fisher, Michael J; Goutagny, Stephane; Harris, Gordon J; Jaramillo, Diego; Karajannis, Matthias A; Korf, Bruce R; Mautner, Victor; Plotkin, Scott R; Poussaint, Tina Y; Robertson, Kent; Shih, Chie-Schin; Widemann, Brigitte C

    2013-11-19

    Neurofibromatosis (NF)-related benign tumors such as plexiform neurofibromas (PN) and vestibular schwannomas (VS) can cause substantial morbidity. Clinical trials directed at these tumors have become available. Due to differences in disease manifestations and the natural history of NF-related tumors, response criteria used for solid cancers (1-dimensional/RECIST [Response Evaluation Criteria in Solid Tumors] and bidimensional/World Health Organization) have limited applicability. No standardized response criteria for benign NF tumors exist. The goal of the Tumor Measurement Working Group of the REiNS (Response Evaluation in Neurofibromatosis and Schwannomatosis) committee is to propose consensus guidelines for the evaluation of imaging response in clinical trials for NF tumors. Currently used imaging endpoints, designs of NF clinical trials, and knowledge of the natural history of NF-related tumors, in particular PN and VS, were reviewed. Consensus recommendations for response evaluation for future studies were developed based on this review and the expertise of group members. MRI with volumetric analysis is recommended to sensitively and reproducibly evaluate changes in tumor size in clinical trials. Volumetric analysis requires adherence to specific imaging recommendations. A 20% volume change was chosen to indicate a decrease or increase in tumor size. Use of these criteria in future trials will enable meaningful comparison of results across studies. The proposed imaging response evaluation guidelines, along with validated clinical outcome measures, will maximize the ability to identify potentially active agents for patients with NF and benign tumors.

  9. Optimization of sampled imaging system with baseband response squeeze model

    NASA Astrophysics Data System (ADS)

    Yang, Huaidong; Chen, Kexin; Huang, Xingyue; He, Qingsheng; Jin, Guofan

    2008-03-01

    When evaluating or designing a sampled imager, a comprehensive analysis is necessary and a trade-off among optics, photoelectric detector and display technique is inevitable. A new method for sampled imaging system evaluation and optimization is developed in this paper. By extension of MTF in sampled imaging system, inseparable parameters of a detector are taken into account and relations among optics, detector and display are revealed. To measure the artifacts of sampling, the Baseband Response Squeeze model, which will impose a penalty for undersampling, is clarified. Taken the squeezed baseband response and its cutoff frequency for favorable criterion, the method is competent not only for evaluating but also for optimizing sampled imaging system oriented either to single task or to multi-task. The method is applied to optimize a typical sampled imaging system. a sensitivity analysis of various detector parameters is performed and the resulted guidelines are given.

  10. Response Classification Images in Vernier Acuity

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Beard, B. L.; Ellis, Stephen R. (Technical Monitor)

    1997-01-01

    Orientation selective and local sign mechanisms have been proposed as the basis for vernier acuity judgments. Linear image features contributing to discrimination can be determined for a two choice task by adding external noise to the images and then averaging the noises separately for the four types of stimulus/response trials. This method is applied to a vernier acuity task with different spatial separations to compare the predictions of the two theories. Three well-practiced observers were presented around 5000 trials of a vernier stimulus consisting of two dark horizontal lines (5 min by 0.3 min) within additive low-contrast white noise. Two spatial separations were tested, abutting and a 10 min horizontal separation. The task was to determine whether the target lines were aligned or vertically offset. The noises were averaged separately for the four stimulus/response trial types (e.g., stimulus = offset, response = aligned). The sum of the two 'not aligned' images was then subtracted from the sum of the 'aligned' images to obtain an overall image. Spatially smoothed images were quantized according to expected variability in the smoothed images to allow estimation of the statistical significance of image features. The response images from the 10 min separation condition are consistent with the local sign theory, having the appearance of two linear operators measuring vertical position with opposite sign. The images from the abutting stimulus have the same appearance with the two operators closer together. The image predicted by an oriented filter model is similar, but has its greatest weight in the abutting region, while the response images fall to nonsignificance there. The response correlation image method, previously demonstrated for letter discrimination, clarifies the features used in vernier acuity.

  11. Response Classification Images in Vernier Acuity

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Beard, B. L.; Ellis, Stephen R. (Technical Monitor)

    1997-01-01

    Orientation selective and local sign mechanisms have been proposed as the basis for vernier acuity judgments. Linear image features contributing to discrimination can be determined for a two choice task by adding external noise to the images and then averaging the noises separately for the four types of stimulus/response trials. This method is applied to a vernier acuity task with different spatial separations to compare the predictions of the two theories. Three well-practiced observers were presented around 5000 trials of a vernier stimulus consisting of two dark horizontal lines (5 min by 0.3 min) within additive low-contrast white noise. Two spatial separations were tested, abutting and a 10 min horizontal separation. The task was to determine whether the target lines were aligned or vertically offset. The noises were averaged separately for the four stimulus/response trial types (e.g., stimulus = offset, response = aligned). The sum of the two 'not aligned' images was then subtracted from the sum of the 'aligned' images to obtain an overall image. Spatially smoothed images were quantized according to expected variability in the smoothed images to allow estimation of the statistical significance of image features. The response images from the 10 min separation condition are consistent with the local sign theory, having the appearance of two linear operators measuring vertical position with opposite sign. The images from the abutting stimulus have the same appearance with the two operators closer together. The image predicted by an oriented filter model is similar, but has its greatest weight in the abutting region, while the response images fall to nonsignificance there. The response correlation image method, previously demonstrated for letter discrimination, clarifies the features used in vernier acuity.

  12. Magnetic Resonance Imaging Evaluation of Cardiac Masses

    PubMed Central

    Braggion-Santos, Maria Fernanda; Koenigkam-Santos, Marcel; Teixeira, Sara Reis; Volpe, Gustavo Jardim; Trad, Henrique Simão; Schmidt, André

    2013-01-01

    Background Cardiac tumors are extremely rare; however, when there is clinical suspicion, proper diagnostic evaluation is necessary to plan the most appropriate treatment. In this context, cardiovascular magnetic resonance imaging (CMRI) plays an important role, allowing a comprehensive characterization of such lesions. Objective To review cases referred to a CMRI Department for investigation of cardiac and paracardiac masses. To describe the positive case series with a brief review of the literature for each type of lesion and the role of cardiovascular magnetic resonance imaging in evaluation. Methods Between August 2008 and December 2011, all cases referred for CMRI with suspicion of tumor involving the heart were reviewed. Cases with positive histopathological diagnosis, clinical evolution or therapeutic response compatible with the clinical suspicion and imaging findings were selected. Results Among the 13 cases included in our study, eight (62%) had histopathological confirmation. We describe five benign tumors (myxomas, rhabdomyoma and fibromas), five malignancies (sarcoma, lymphoma, Richter syndrome involving the heart and metastatic disease) and three non-neoplastic lesions (pericardial cyst, intracardiac thrombus and infectious vegetation). Conclusion CMRI plays an important role in the evaluation of cardiac masses of non-neoplastic and neoplastic origin, contributing to a more accurate diagnosis in a noninvasive manner and assisting in treatment planning, allowing safe clinical follow-up with good reproducibility. PMID:23887734

  13. Role of 3T multiparametric-MRI with BOLD hypoxia imaging for diagnosis and post therapy response evaluation of postoperative recurrent cervical cancers.

    PubMed

    Mahajan, Abhishek; Engineer, Reena; Chopra, Supriya; Mahanshetty, Umesh; Juvekar, S L; Shrivastava, S K; Desekar, Naresh; Thakur, M H

    2016-01-01

    To assess the diagnostic value of multiparametric-MRI (MPMRI) with hypoxia imaging as a functional marker for characterizing and detecting vaginal vault/local recurrence following primary surgery for cervical cancer. With institutional review board approval and written informed consent 30 women (median age: 45 years) from October 2009 to March 2010 with previous operated carcinoma cervix and suspected clinical vaginal vault/local recurrence were examined with 3.0T-MRI. MRI imaging included conventional and MPMRI sequences [dynamic contrast enhanced (DCE), diffusion weighted (DW), 1H-MR spectroscopy (1HMRS), blood oxygen level dependent hypoxia imaging (BOLD)]. Two radiologists, blinded to pathologic findings, independently assessed the pretherapy MRI findings and then correlated it with histopathology findings. Sensitivity, specificity, positive predictive value, negative predictive value and their confidence intervals were calculated. The pre and post therapy conventional and MPMRI parameters were analyzed and correlated with response to therapy. Of the 30 patients, there were 24 recurrent tumors and 6 benign lesions. The accuracy of diagnosing recurrent vault lesions was highest at combined MPMRI and conventional MRI (100%) than at conventional-MRI (70%) or MPMRI (96.7%) alone. Significant correlation was seen between percentage tumor regression and pre-treatment parameters such as negative enhancement integral (NEI) (p = 0.02), the maximum slope (p = 0.04), mADC value (p = 0.001) and amount of hypoxic fraction on the pretherapy MRI (p = 0.01). Conventional-MR with MPMRI significantly increases the diagnostic accuracy for suspected vaginal vault/local recurrence. Post therapy serial MPMRI with hypoxia imaging follow-up objectively documents the response. MPMRI and BOLD hypoxia imaging provide information regarding tumor biology at the molecular, subcellular, cellular and tissue levels and this information may be used as an appropriate and reliable

  14. Evaluation of early response to concomitant chemoradiotherapy by interim 18F-FDG PET/CT imaging in patients with locally advanced oesophageal carcinomas.

    PubMed

    Cuenca, Xavier; Hennequin, Christophe; Hindié, Elif; Rivera, Sofia; Vercellino, Laetitia; Baruch-Hennequin, Valérie; Gornet, Jean-Marc; Cattan, Pierre; Chirica, Mircea; Quéro, Laurent

    2013-04-01

    The best way to assess the response to chemoradiotherapy of locally advanced oesophageal carcinomas is not known. We used (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT to evaluate the metabolic response during chemoradiotherapy and tried to correlate this response to survival. Patients with biopsy-proven oesophageal carcinoma underwent FDG PET/CT with evaluation of the standardized uptake value (SUV) before any treatment (SUV1) and during chemoradiotherapy after two cycles of 5-fluorouracil (FU)/cisplatin and 20 Gy (SUV2). Metabolic response was defined as 1-(SUV2/SUV1). Surgery was discussed after 40 Gy and three cycles of chemotherapy. Results of interim PET were not considered for the therapeutic decision. Among 72 patients who underwent a first FDG PET/CT before any treatment, 59 (82 %) could receive the second FDG PET/CT examination. Median survival was 22.2 months with 1-year and 2-year survivals of 70 and 46 %, respectively. Nineteen patients (32 %) underwent surgery. Mean SUV1 and SUV2 were 12.3 ± 6.2 and 6 ± 4.1, respectively (p < 0.001). Using a cut-off for metabolic response of 50 %, sensitivity and specificity for survival were 0.7 and 0.58. The 2-year overall survival of good responders was 62 % as compared to 27 % for poor metabolic responders. A multivariate analysis was performed, including T and N stages, surgery, histology and metabolic response: only metabolic response was significantly (p = 0.009) associated with 2-year survival. Early evaluation of metabolic response had a great prognostic value and could help identify good responders to chemoradiotherapy.

  15. Image analysis of neuropsychological test responses

    NASA Astrophysics Data System (ADS)

    Smith, Stephen L.; Hiller, Darren L.

    1996-04-01

    This paper reports recent advances in the development of an automated approach to neuropsychological testing. High performance image analysis algorithms have been developed as part of a convenient and non-invasive computer-based system to provide an objective assessment of patient responses to figure-copying tests. Tests of this type are important in determining the neurological function of patients following stroke through evaluation of their visuo-spatial performance. Many conventional neuropsychological tests suffer from the serious drawback that subjective judgement on the part of the tester is required in the measurement of the patient's response which leads to a qualitative neuropsychological assessment that can be both inconsistent and inaccurate. Results for this automated approach are presented for three clinical populations: patients suffering right hemisphere stroke are compared with adults with no known neurological disorder and a population comprising normal school children of 11 years is presented to demonstrate the sensitivity of the technique. As well as providing a more reliable and consistent diagnosis this technique is sufficiently sensitive to monitor a patient's progress over a period of time and will provide the neuropsychologist with a practical means of evaluating the effectiveness of therapy or medication administered as part of a rehabilitation program.

  16. Anniversary paper: evaluation of medical imaging systems.

    PubMed

    Krupinski, Elizabeth A; Jiang, Yulei

    2008-02-01

    Medical imaging used to be primarily within the domain of radiology, but with the advent of virtual pathology slides and telemedicine, imaging technology is expanding in the healthcare enterprise. As new imaging technologies are developed, they must be evaluated to assess the impact and benefit on patient care. The authors review the hierarchical model of the efficacy of diagnostic imaging systems by Fryback and Thornbury [Med. Decis. Making 11, 88-94 (1991)] as a guiding principle for system evaluation. Evaluation of medical imaging systems encompasses everything from the hardware and software used to acquire, store, and transmit images to the presentation of images to the interpreting clinician. Evaluation of medical imaging systems can take many forms, from the purely technical (e.g., patient dose measurement) to the increasingly complex (e.g., determining whether a new imaging method saves lives and benefits society). Evaluation methodologies cover a broad range, from receiver operating characteristic (ROC) techniques that measure diagnostic accuracy to timing studies that measure image-interpretation workflow efficiency. The authors review briefly the history of the development of evaluation methodologies and review ROC methodology as well as other types of evaluation methods. They discuss unique challenges in system evaluation that face the imaging community today and opportunities for future advances.

  17. Uveal melanoma: quantitative evaluation of diffusion-weighted MR imaging in the response assessment after proton-beam therapy, long-term follow-up.

    PubMed

    Foti, Pietro Valerio; Longo, Antonio; Reibaldi, Michele; Russo, Andrea; Privitera, Giuseppe; Spatola, Corrado; Raffaele, Luigi; Salamone, Vincenzo; Farina, Renato; Palmucci, Stefano; Musumeci, Andrea; Caltabiano, Rosario; Ragusa, Marco; Mariotti, Cesare; Avitabile, Teresio; Milone, Pietro; Ettorre, Giovanni Carlo

    2017-02-01

    The purpose of this prospective study was to investigate the proton-beam-induced changes in apparent diffusion coefficient (ADC) values of ocular melanoma treated with proton-beam therapy (PBT) in patients undergoing long-term magnetic resonance imaging (MRI) follow-up and to assess whether variations in ADC constitute a reliable biomarker for predicting and detecting the response of ocular melanoma to PBT. Seventeen patients with ocular melanoma treated with PBT were enrolled. All patients underwent conventional MRI and diffusion-weighted imaging (DWI) at baseline and 1, 3, 6, and 18 months after the beginning of therapy. Tumor volumes and ADC values of ocular lesions were measured at each examination. Tumor volumes and mean ADC measurements of the five examination series were compared; correlation of ADC values and tumor regression was estimated. Mean ADC values of ocular melanomas significantly increased already 1 month after therapy whereas tumor volume significantly decreased only 6 months after therapy. Pretreatment ADC value of ocular melanomas and early change in ADC value 1 month after therapy significantly correlated with tumor regression. In ocular melanoma treated with PBT, ADC variations precede volume changes. Both pretreatment ADC and early change in ADC value may predict treatment response, thus expanding the role of DWI from diagnostic to prognostic.

  18. Evaluation of diffusion-weighted imaging as a predictive marker for tumor response in patients undergoing chemoradiation for postoperative recurrences of cervical cancer.

    PubMed

    Chopra, Supriya; Verma, Ashish; Kundu, Sayan; Engineer, Reena; Medhi, Seema; Mahantshetty, Umesh; Gupta, Sudeep; Shrivastava, Shyam K

    2012-01-01

    To investigate diffusion-weighted imaging (DWI) as a response biomarker in patients undergoing chemoradiation for postoperative recurrences of cervical cancer. From October 2008 to March 2011, 20 patients were included. All underwent T2-weighted (T2W) and DWI before and after chemoradiation. Gross tumor volume (GTV), lateral extent, apparent diffusion coefficient (ADC), and presence of regions of focally restricted diffusion were determined at baseline. Response to chemoradiation was categorized as either partial or complete. Receiver operator characteristics (ROC) curve identified thresholds of GTV and ADC that best predict for partial response. Univariate and multivariate analysis were performed on SPSS version 15. The median GTV was 24.5 cc (4.1-110 cc). Central and lateral disease was present in 8 and 12 patients, respectively. The median ADC was 1 × 10 -3 mm² /s (0.8-1.3 × 10⁻³ mm² /s) and 12/20 (60%) patients had focal restricted diffusion. Overall 10/20 patients had partial response. ROC analysis identified volume of 25 cc or higher [sensitivity = 80%, specificity = 80%, area under curve (AUC) = 0.76, P = 0.04] and ADC more than 1 × 10⁻³ mm² /s (sensitivity = 70%, specificity = 50%, AUC = 0.62; P = 0.34) to best predict for partial response. On univariate analysis bulky disease (77.7% vs. 27%; P = 0.03), lateral disease (66.6% vs. 25%; P = 0.08), and focal regions of restricted diffusion (66.6% vs. 25%; P = 0.06) predicted for partial response to chemoradiation. All factors continued to be significant on multivariate analysis. On restricting analysis to bulky tumors ADC greater than 0.95 × 10⁻³ mm² /s predicted partial response with high sensitivity (85.7%) and specificity (100%) (AUC 0.96; P = 0.05). On univariate analysis lateral disease (P = 0.04), high baseline ADC (P = 0.07) predicted for partial response. Baseline ADC and focal regions of ADC restriction predict for partial response with moderate sensitivity and specificity in patients

  19. Evaluating Image Browsers Using Structured Annotation.

    ERIC Educational Resources Information Center

    Muller, Wolfgang; Marchand-Mailet, Stephane; Muller, Henning; Squire, David McG.; Pun, Thierry

    2001-01-01

    Addresses the problem of benchmarking image browsers. Existence of different search paradigms for image browsers makes it difficult to compare them. Currently, the only admissible evaluation method involves conducting large-scale user studies. An automatic image browser benchmark is proposed that uses structured text annotation of the image…

  20. Non-Hodgkin lymphoma response evaluation with MRI texture classification

    PubMed Central

    Harrison, Lara CV; Luukkaala, Tiina; Pertovaara, Hannu; Saarinen, Tuomas O; Heinonen, Tomi T; Järvenpää, Ritva; Soimakallio, Seppo; Kellokumpu-Lehtinen, Pirkko-Liisa I; Eskola, Hannu J; Dastidar, Prasun

    2009-01-01

    Background To show magnetic resonance imaging (MRI) texture appearance change in non-Hodgkin lymphoma (NHL) during treatment with response controlled by quantitative volume analysis. Methods A total of 19 patients having NHL with an evaluable lymphoma lesion were scanned at three imaging timepoints with 1.5T device during clinical treatment evaluation. Texture characteristics of images were analyzed and classified with MaZda application and statistical tests. Results NHL tissue MRI texture imaged before treatment and under chemotherapy was classified within several subgroups, showing best discrimination with 96% correct classification in non-linear discriminant analysis of T2-weighted images. Texture parameters of MRI data were successfully tested with statistical tests to assess the impact of the separability of the parameters in evaluating chemotherapy response in lymphoma tissue. Conclusion Texture characteristics of MRI data were classified successfully; this proved texture analysis to be potential quantitative means of representing lymphoma tissue changes during chemotherapy response monitoring. PMID:19545438

  1. Image capture: simulation of sensor responses from hyperspectral images.

    PubMed

    Vora, P L; Farrell, J E; Tietz, J D; Brainard, D H

    2001-01-01

    This paper describes the design and performance of an image capture simulator. The general model underlying the simulator assumes that the image capture device contains multiple classes of sensors with different spectral sensitivities and that each sensor responds in a known way to irradiance over most of its operating range. The input to the simulator is a set of narrow-band images of the scene taken with a custom-designed hyperspectral camera system. The parameters for the simulator are the number of sensor classes, the sensor spectral sensitivities, the noise statistics and number of quantization levels for each sensor class, the spatial arrangement of the sensors and the exposure duration. The output of the simulator is the raw image data that would have been acquired by the simulated image capture device. To test the simulator, we acquired images of the same scene both with the hyperspectral camera and with a calibrated Kodak DCS-200 digital color camera. We used the simulator to predict the DCS-200 output from the hyperspectral data. The agreement between simulated and acquired images validated the image capture response model and our simulator implementation. We believe the simulator will provide a useful tool for understanding the effect of varying the design parameters of an image capture device.

  2. Evaluation metric of an image understanding result

    NASA Astrophysics Data System (ADS)

    Hemery, Baptiste; Laurent, Helene; Emile, Bruno; Rosenberger, Christophe

    2015-01-01

    Image processing algorithms include methods that process images from their acquisition to the extraction of useful information for a given application. Among interpretation algorithms, some are designed to detect, localize, and identify one or several objects in an image. The problem addressed is the evaluation of the interpretation results of an image or a video given an associated ground truth. Challenges are multiple, such as the comparison of algorithms, evaluation of an algorithm during its development, or the definition of its optimal settings. We propose a new metric for evaluating the interpretation result of an image. The advantage of the proposed metric is to evaluate a result by taking into account the quality of the localization, recognition, and detection of objects of interest in the image. Several parameters allow us to change the behavior of this metric for a given application. Its behavior has been tested on a large database and showed interesting results.

  3. Image performance evaluation of a 3D surgical imaging platform

    NASA Astrophysics Data System (ADS)

    Petrov, Ivailo E.; Nikolov, Hristo N.; Holdsworth, David W.; Drangova, Maria

    2011-03-01

    The O-arm (Medtronic Inc.) is a multi-dimensional surgical imaging platform. The purpose of this study was to perform a quantitative evaluation of the imaging performance of the O-arm in an effort to understand its potential for future nonorthopedic applications. Performance of the reconstructed 3D images was evaluated, using a custom-built phantom, in terms of resolution, linearity, uniformity and geometrical accuracy. Both the standard (SD, 13 s) and high definition (HD, 26 s) modes were evaluated, with the imaging parameters set to image the head (120 kVp, 100 mAs and 150 mAs, respectively). For quantitative noise characterization, the images were converted to Hounsfield units (HU) off-line. Measurement of the modulation transfer function revealed a limiting resolution (at 10% level) of 1.0 mm-1 in the axial dimension. Image noise varied between 15 and 19 HU for the HD and SD modes, respectively. Image intensities varied linearly over the measured range, up to 1300 HU. Geometric accuracy was maintained in all three dimensions over the field of view. The present study has evaluated the performance characteristics of the O-arm, and demonstrates feasibility for use in interventional applications and quantitative imaging tasks outside those currently targeted by the manufacturer. Further improvements to the reconstruction algorithms may further enhance performance for lower-contrast applications.

  4. Hyperspectral imaging for nondestructive evaluation of tomatoes

    USDA-ARS?s Scientific Manuscript database

    Machine vision methods for quality and defect evaluation of tomatoes have been studied for online sorting and robotic harvesting applications. We investigated the use of a hyperspectral imaging system for quality evaluation and defect detection for tomatoes. Hyperspectral reflectance images were a...

  5. Electromagnetic Imaging Methods for Nondestructive Evaluation Applications

    PubMed Central

    Deng, Yiming; Liu, Xin

    2011-01-01

    Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions. PMID:22247693

  6. Electromagnetic imaging methods for nondestructive evaluation applications.

    PubMed

    Deng, Yiming; Liu, Xin

    2011-01-01

    Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions.

  7. Using Responsive Evaluation To Evaluate a Professional Conference.

    ERIC Educational Resources Information Center

    Speigel, Amy N.; Bruning, Roger H.; Giddings, Lisa

    1999-01-01

    Incorporated responsive evaluation methods into the structure of a professional conference and illustrated the usefulness of these techniques in evaluating conferences. Discusses the implications of this pilot study of responsive evaluation. (SLD)

  8. Process perspective on image quality evaluation

    NASA Astrophysics Data System (ADS)

    Leisti, Tuomas; Halonen, Raisa; Kokkonen, Anna; Weckman, Hanna; Mettänen, Marja; Lensu, Lasse; Ritala, Risto; Oittinen, Pirkko; Nyman, Göte

    2008-01-01

    The psychological complexity of multivariate image quality evaluation makes it difficult to develop general image quality metrics. Quality evaluation includes several mental processes and ignoring these processes and the use of a few test images can lead to biased results. By using a qualitative/quantitative (Interpretation Based Quality, IBQ) methodology, we examined the process of pair-wise comparison in a setting, where the quality of the images printed by laser printer on different paper grades was evaluated. Test image consisted of a picture of a table covered with several objects. Three other images were also used, photographs of a woman, cityscape and countryside. In addition to the pair-wise comparisons, observers (N=10) were interviewed about the subjective quality attributes they used in making their quality decisions. An examination of the individual pair-wise comparisons revealed serious inconsistencies in observers' evaluations on the test image content, but not on other contexts. The qualitative analysis showed that this inconsistency was due to the observers' focus of attention. The lack of easily recognizable context in the test image may have contributed to this inconsistency. To obtain reliable knowledge of the effect of image context or attention on subjective image quality, a qualitative methodology is needed.

  9. DoD Advanced, Image-Evaluation Program

    DTIC Science & Technology

    1974-06-01

    Module 40 14 Two-Port, Image- Evaluation Concept 43 15 Basic Schematic for System Responsivity Measurements 48 16 Basic Schematic for System Spatial...Response Measurements 49 17 Basic Schematic for System Resoltivity Response Measurements 50 18 Example of Point Source Spreading 62 viii TABLES Table...Hybrid Target Generator Component Specifications (Visible) 31 Target Pattern Specifications 32 6 Extended Basic Commands 38-39 Typical Software Supported

  10. Performance evaluation of image segmentation algorithms on microscopic image data.

    PubMed

    Beneš, Miroslav; Zitová, Barbara

    2015-01-01

    In our paper, we present a performance evaluation of image segmentation algorithms on microscopic image data. In spite of the existence of many algorithms for image data partitioning, there is no universal and 'the best' method yet. Moreover, images of microscopic samples can be of various character and quality which can negatively influence the performance of image segmentation algorithms. Thus, the issue of selecting suitable method for a given set of image data is of big interest. We carried out a large number of experiments with a variety of segmentation methods to evaluate the behaviour of individual approaches on the testing set of microscopic images (cross-section images taken in three different modalities from the field of art restoration). The segmentation results were assessed by several indices used for measuring the output quality of image segmentation algorithms. In the end, the benefit of segmentation combination approach is studied and applicability of achieved results on another representatives of microscopic data category - biological samples - is shown.

  11. Variations of dynamic contrast-enhanced magnetic resonance imaging in evaluation of breast cancer therapy response: a multicenter data analysis challenge.

    PubMed

    Huang, Wei; Li, Xin; Chen, Yiyi; Li, Xia; Chang, Ming-Ching; Oborski, Matthew J; Malyarenko, Dariya I; Muzi, Mark; Jajamovich, Guido H; Fedorov, Andriy; Tudorica, Alina; Gupta, Sandeep N; Laymon, Charles M; Marro, Kenneth I; Dyvorne, Hadrien A; Miller, James V; Barbodiak, Daniel P; Chenevert, Thomas L; Yankeelov, Thomas E; Mountz, James M; Kinahan, Paul E; Kikinis, Ron; Taouli, Bachir; Fennessy, Fiona; Kalpathy-Cramer, Jayashree

    2014-02-01

    Pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) time-course data allows estimation of quantitative parameters such as K (trans) (rate constant for plasma/interstitium contrast agent transfer), v e (extravascular extracellular volume fraction), and v p (plasma volume fraction). A plethora of factors in DCE-MRI data acquisition and analysis can affect accuracy and precision of these parameters and, consequently, the utility of quantitative DCE-MRI for assessing therapy response. In this multicenter data analysis challenge, DCE-MRI data acquired at one center from 10 patients with breast cancer before and after the first cycle of neoadjuvant chemotherapy were shared and processed with 12 software tools based on the Tofts model (TM), extended TM, and Shutter-Speed model. Inputs of tumor region of interest definition, pre-contrast T1, and arterial input function were controlled to focus on the variations in parameter value and response prediction capability caused by differences in models and associated algorithms. Considerable parameter variations were observed with the within-subject coefficient of variation (wCV) values for K (trans) and v p being as high as 0.59 and 0.82, respectively. Parameter agreement improved when only algorithms based on the same model were compared, e.g., the K (trans) intraclass correlation coefficient increased to as high as 0.84. Agreement in parameter percentage change was much better than that in absolute parameter value, e.g., the pairwise concordance correlation coefficient improved from 0.047 (for K (trans)) to 0.92 (for K (trans) percentage change) in comparing two TM algorithms. Nearly all algorithms provided good to excellent (univariate logistic regression c-statistic value ranging from 0.8 to 1.0) early prediction of therapy response using the metrics of mean tumor K (trans) and k ep (=K (trans)/v e, intravasation rate constant) after the first therapy cycle and the corresponding

  12. MR imaging evaluation of the postoperative meniscus.

    PubMed

    Russo, A; Capasso, R; Varelli, C; Laporta, A; Carbone, M; D'Agosto, G; Giovine, S; Zappia, M; Reginelli, A

    2017-03-01

    MR imaging has been widely evaluated in the assessment of patients with recurrent or residual symptoms following meniscal surgery. Importantly, the causes of such symptoms may relate to failure or complication of the surgical procedure, a possible recurrent or residual meniscal tear, or may be related to other causes of joint symptoms, including tears of the contralateral meniscus, or local hyaline cartilage, or marrow abnormalities subjacent to or distant to the meniscal surgical site. The complex diagnostic issues involved in the MR imaging evaluation of the postoperative meniscus were identified in early MR imaging studies. The knowledge of the normal MR imaging appearance of the knee after the more common repair procedures will allow radiologists to recognize complications associated with such procedures. In this article, we discuss the MR imaging evaluation of the knee after meniscal surgery.

  13. Novel imaging techniques as response biomarkers in cervical cancer.

    PubMed

    Harry, Vanessa N

    2010-02-01

    The use of novel imaging techniques that have the ability to evaluate tumour biology and function shows a great deal of promise in providing early surrogate biomarkers of response to therapy which may allow for individualised or patient-specific regimes. This would have considerable clinical benefit in allowing for a treatment regimen tailored accordingly to meet the expected response, thereby reducing morbidity. Several of these imaging modalities such as dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted MRI (DW-MRI), MR spectroscopy (MRS) and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) are now being introduced into the field of gynaecological oncology, with the majority of work being performed on cervical tumours. This review examines the use of these functional imaging techniques as response biomarkers in cervical cancer. Copyright 2009 Elsevier Inc. All rights reserved.

  14. Evaluation of Carotid Plaque Using Ultrasound Imaging

    PubMed Central

    2016-01-01

    Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk. PMID:27358696

  15. Evaluation of imaging performance of major image guidance systems

    PubMed Central

    Chan, MF; Yang, J; Song, Y; Burman, C; Chan, P; Li, S

    2011-01-01

    Purpose: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in image-guided radiation therapy (IGRT) were evaluated. Materials and methods: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution. The measurement results were analysed using in-house image analysis software. Reproducibility, position correction, and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT). Results: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2–4 times higher than that of the Varian CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively. Conclusion: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning. Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity. PMID:22287985

  16. Imaging Leukocyte Responses in the Kidney.

    PubMed

    Finsterbusch, Michaela; Kitching, A Richard; Hickey, Michael J

    2017-03-01

    The kidney can be negatively affected by a range of innate and adaptive immune responses, resulting in alterations in the functions of the kidney and, in some cases, progression to renal failure. In many of these responses, infiltration of blood-borne leukocytes into the kidney is central to the response. In addition, a large population of mononuclear phagocytes resident in the kidney can modulate these responses. A great deal of research has investigated both the mechanisms of leukocyte recruitment to the kidney and the actions of immune cells resident within the kidney. Because of the dynamic nature of the processes whereby leukocytes enter sites of inflammation, in vivo imaging has been one of the key approaches used for understanding leukocyte recruitment as it occurs throughout the body, and this is also true for kidney. However, imaging this organ and its complicated microvasculature during different forms of renal pathology presents a unique set of challenges. In this review, we examine the approaches used for intravital imaging of the kidney and summarize the insights gained from these studies regarding the mechanisms of leukocyte entry into the kidney during inflammation and the actions of immune cells within this organ.

  17. Research on image scrambling degree evaluation method

    NASA Astrophysics Data System (ADS)

    Bai, Sen; Liao, Xiaofeng; Chen, Jinyu; Liu, Yijun; Wang, Xiao

    2005-12-01

    This paper discussed the evaluation problem of image scrambling degree (ISD). Inspired by the evaluation method of image texture characteristics, three new metrics for assessing objectively the ISD were proposed. The first method utilized the performance of energy concentration of Walsh transformation (WT), which took into account the properties that a good ISD measurement method should be contented. The second method used angular second moment (ASM) of image gray level co-occurrence matrix (GLCM). The third method combined the entropy of GLCM with image texture characteristic. Experimental results show that the proposed metrics are effective to assess the ISD, which correlates well with subjective assessment. Considering the computational complexity, the first evaluation method based on WT is remarkably superior to the method based on ASM and GLCM in terms of the time cost.

  18. Changing CS Features Alters Evaluative Responses in Evaluative Conditioning

    ERIC Educational Resources Information Center

    Unkelbach, Christian; Stahl, Christoph; Forderer, Sabine

    2012-01-01

    Evaluative conditioning (EC) refers to changes in people's evaluative responses toward initially neutral stimuli (CSs) by mere spatial and temporal contiguity with other positive or negative stimuli (USs). We investigate whether changing CS features from conditioning to evaluation also changes people's evaluative response toward these CSs. We used…

  19. Changing CS Features Alters Evaluative Responses in Evaluative Conditioning

    ERIC Educational Resources Information Center

    Unkelbach, Christian; Stahl, Christoph; Forderer, Sabine

    2012-01-01

    Evaluative conditioning (EC) refers to changes in people's evaluative responses toward initially neutral stimuli (CSs) by mere spatial and temporal contiguity with other positive or negative stimuli (USs). We investigate whether changing CS features from conditioning to evaluation also changes people's evaluative response toward these CSs. We used…

  20. Immunofluorescence Imaging of DNA Damage Response Proteins

    PubMed Central

    Bennett, Brian T.; Bewersdorf, Jörg; Knight, Kendall L.

    2013-01-01

    Immunofluorescence imaging has provided captivating visual evidence for numerous cellular events, from vesicular trafficking, organelle maturation and cell division to nuclear processes including the appearance of various proteins and chromatin components in distinct foci in response to DNA damaging agents. With the advent of new super-resolution microscope technologies such as 4Pi microscopy, standard immunofluorescence protocols deserve some reevaluation in order to take full advantage of these new technological accomplishments. Here we describe several methodological considerations that will help overcome some of the limitations that may result from the use of currently applied procedures, with particular attention paid to the analysis of possible colocalization of fluorescent signals. We conclude with an example of how application of optimized methods led to a breakthrough in super-resolution imaging of nuclear events occurring in response to DNA damage. PMID:19245833

  1. Color image processing for date quality evaluation

    NASA Astrophysics Data System (ADS)

    Lee, Dah Jye; Archibald, James K.

    2010-01-01

    Many agricultural non-contact visual inspection applications use color image processing techniques because color is often a good indicator of product quality. Color evaluation is an essential step in the processing and inventory control of fruits and vegetables that directly affects profitability. Most color spaces such as RGB and HSV represent colors with three-dimensional data, which makes using color image processing a challenging task. Since most agricultural applications only require analysis on a predefined set or range of colors, mapping these relevant colors to a small number of indexes allows simple and efficient color image processing for quality evaluation. This paper presents a simple but efficient color mapping and image processing technique that is designed specifically for real-time quality evaluation of Medjool dates. In contrast with more complex color image processing techniques, the proposed color mapping method makes it easy for a human operator to specify and adjust color-preference settings for different color groups representing distinct quality levels. Using this color mapping technique, the color image is first converted to a color map that has one color index represents a color value for each pixel. Fruit maturity level is evaluated based on these color indices. A skin lamination threshold is then determined based on the fruit surface characteristics. This adaptive threshold is used to detect delaminated fruit skin and hence determine the fruit quality. The performance of this robust color grading technique has been used for real-time Medjool date grading.

  2. Evaluation of co-added astronomical images

    NASA Astrophysics Data System (ADS)

    Nasyrova, M.; Vítek, S.

    2017-07-01

    The co-adding, averaging, or stacking of data are popular techniques to improve scientific outcomes in astronomy, especially in the case of extraction of very faint sources. These methods allow to increase the signal-to-noise ratio and to decrease the point spread function width, which improves the accuracy of segmentation. This paper deals with a brief review of image co-adding algorithms and their evaluation regarding improving the qualitative parameters of the image data.

  3. Evaluation of allergic response using dynamic thermography

    NASA Astrophysics Data System (ADS)

    Rokita, E.; Rok, T.; Tatoń, G.

    2015-03-01

    Skin dynamic termography supplemented by a mathematical model is presented as an objective and sensitive indicator of the skin prick test result. Termographic measurements were performed simultaneously with routine skin prick tests. The IR images were acquired every 70 s up to 910 s after skin prick. In the model histamine is treated as the principal mediator of the allergic reaction. Histamine produces vasolidation and the engorged vessels are responsible for an increase in skin temperature. The model parameters were determined by fitting the analytical solutions to the spatio-temporal distributions of the differences between measured and baseline temperatures. The model reproduces experimental data very well (coefficient of determination = 0.805÷0.995). The method offers a set of parameters to describe separately skin allergic reaction and skin reactivity. The release of histamine after allergen injection is the best indicator of allergic response. The diagnostic parameter better correlates with the standard evaluation of a skin prick test (correlation coefficient = 0.98) than the result of the thermographic planimetric method based on temperature and heated area determination (0.81). The high sensitivity of the method allows for determination of the allergic response in patients with the reduced skin reactivity.

  4. Aligning Collaborative and Culturally Responsive Evaluation Approaches

    ERIC Educational Resources Information Center

    Askew, Karyl; Beverly, Monifa Green; Jay, Michelle L.

    2012-01-01

    The authors, three African-American women trained as collaborative evaluators, offer a comparative analysis of collaborative evaluation (O'Sullivan, 2004) and culturally responsive evaluation approaches (Frierson, Hood, & Hughes, 2002; Kirkhart & Hopson, 2010). Collaborative evaluation techniques immerse evaluators in the cultural milieu…

  5. Improving Beta Test Evaluation Response Rates: A Meta-Evaluation

    ERIC Educational Resources Information Center

    Russ-Eft, Darlene; Preskill, Hallie

    2005-01-01

    This study presents a meta-evaluation of a beta-test of a customer service training program. The initial evaluation showed a low response rate. Therefore, the meta-evaluation focused on issues related to the conduct of the initial evaluation and reasons for nonresponse. The meta-evaluation identified solutions to the nonresponse problem as related…

  6. The Practice and Politics of Responsive Evaluation

    ERIC Educational Resources Information Center

    Abma, Tineke

    2006-01-01

    Responsive evaluation offers a perspective in which evaluation is reframed from the assessment of program interventions on the basis of policy makers' goals to an engagement with and among all stakeholders about the value and meaning of their practice. Responsive evaluators have to be extra sensitive to power relations given the deliberate…

  7. MTF evaluation of in-line phase contrast imaging system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoran; Gao, Feng; Zhao, Huijuan; Zhang, Limin; Li, Jiao; Zhou, Zhongxing

    2017-02-01

    X-ray phase contrast imaging (XPCI) is a novel method that exploits the phase shift for the incident X-ray to form an image. Various XPCI methods have been proposed, among which, in-line phase contrast imaging (IL-PCI) is regarded as one of the most promising clinical methods. The contrast of the interface is enhanced due to the introduction of the boundary fringes in XPCI, thus it is generally used to evaluate the image quality of XPCI. But the contrast is a comprehensive index and it does not reflect the information of image quality in the frequency range. The modulation transfer function (MTF), which is the Fourier transform of the system point spread function, is recognized as the metric to characterize the spatial response of conventional X-ray imaging system. In this work, MTF is introduced into the image quality evaluation of the IL-PCI system. Numerous simulations based on Fresnel - Kirchhoff diffraction theory are performed with varying system settings and the corresponding MTFs were calculated for comparison. The results show that MTF can provide more comprehensive information of image quality comparing to contrast in IL-PCI.

  8. Evaluation Tools for Image Information Mining System

    NASA Astrophysics Data System (ADS)

    Daschiel, H.; Datcu, M.

    2004-09-01

    In this article, we present tools for the evaluation of a knowledge-drivencontent-based image information mining system. In order to provide users fast access to the content of large remote sensing image archives, the system is composed of two main modules. The first includes computationally intensive algorithms for off-line data ingestion in the database, feature extraction and indexing. The second module consists of a graphical human-machine interface that manages the interactive learning and image information mining functions. According to the system architecture, the implemented evaluation tools determine the objective technical quality of the system and include subjective human factors, too. Since the query performance of the mining system mainly depends on the data sets stored in the archive, we first analyze the complexityof image data. Based on the stochastic nature of user-defined semantic cover-type labels, the system retrieves the most relevant images using probabilistic measurements. We evaluate the man-machine communication dialogue and system operation in order to determine the quality of semantic labels. Finally, we verify the man-machine interfaceby using measurements like time for loading the learning applet, time for computing the probabilistic search results and time for label training.

  9. Dual-Enzyme-Loaded Multifunctional Hybrid Nanogel System for Pathological Responsive Ultrasound Imaging and T2-Weighted Magnetic Resonance Imaging.

    PubMed

    Wang, Xia; Niu, Dechao; Li, Pei; Wu, Qing; Bo, Xiaowan; Liu, Boji; Bao, Song; Su, Teng; Xu, Huixiong; Wang, Qigang

    2015-06-23

    A dual-enzyme-loaded multifunctional hybrid nanogel probe (SPIO@GCS/acryl/biotin-CAT/SOD-gel, or SGC) has been developed for dual-modality pathological responsive ultrasound (US) imaging and enhanced T2-weighted magnetic resonance (MR) imaging. This probe is composed of functionalized superparamagnetic iron oxide particles, a dual enzyme species (catalase and superoxide dismutase), and a polysaccharide cationic polymer glycol chitosan gel. The dual-modality US/MR imaging capabilities of the hybrid nanogel for responsive US imaging and enhanced T2-weighted MR imaging have been evaluated both in vitro and in vivo. These results show that the hybrid nanogel SGC can exhibit efficient dual-enzyme biocatalysis with pathological species for responsive US imaging. SGC also demonstrates increased accumulation in acidic environments for enhanced T2-weighted MR imaging. Further research on these nanogel systems may lead to the development of more efficient US/MR contrast agents.

  10. Image Inpainting Methods Evaluation and Improvement

    PubMed Central

    Vreja, Raluca

    2014-01-01

    With the upgrowing of digital processing of images and film archiving, the need for assisted or unsupervised restoration required the development of a series of methods and techniques. Among them, image inpainting is maybe the most impressive and useful. Based on partial derivative equations or texture synthesis, many other hybrid techniques have been proposed recently. The need for an analytical comparison, beside the visual one, urged us to perform the studies shown in the present paper. Starting with an overview of the domain, an evaluation of the five methods was performed using a common benchmark and measuring the PSNR. Conclusions regarding the performance of the investigated algorithms have been presented, categorizing them in function of the restored image structure. Based on these experiments, we have proposed an adaptation of Oliveira's and Hadhoud's algorithms, which are performing well on images with natural defects. PMID:25136700

  11. Image inpainting methods evaluation and improvement.

    PubMed

    Vreja, Raluca; Brad, Remus

    2014-01-01

    With the upgrowing of digital processing of images and film archiving, the need for assisted or unsupervised restoration required the development of a series of methods and techniques. Among them, image inpainting is maybe the most impressive and useful. Based on partial derivative equations or texture synthesis, many other hybrid techniques have been proposed recently. The need for an analytical comparison, beside the visual one, urged us to perform the studies shown in the present paper. Starting with an overview of the domain, an evaluation of the five methods was performed using a common benchmark and measuring the PSNR. Conclusions regarding the performance of the investigated algorithms have been presented, categorizing them in function of the restored image structure. Based on these experiments, we have proposed an adaptation of Oliveira's and Hadhoud's algorithms, which are performing well on images with natural defects.

  12. Local wavefield velocity imaging for damage evaluation

    NASA Astrophysics Data System (ADS)

    Chia, Chen Ciang; Gan, Chia Sheng; Mustapha, F.

    2017-02-01

    Ultrasonic Propagation Imaging or Acoustic Wavefield Imaging has been widely used to evaluate structural damages and internal features. Inspecting complete wavefield time history for damage identification is tedious and error-prone. A more effective way is by extracting damage-related information into a single image. A wavefield velocity imaging method that maps the local estimates of group or phase velocity is proposed. Actual velocity values rather than arbitrarily-scaled intensities are mapped, enabling damage sizing without the need of supervised training or inspecting wavefield propagation video. Performance of the proposed method was tested by inspecting a 100 mm by 100 mm area of a 2 mm thick stainless steel specimen. Local phase velocity maps of A0 mode showed a half-thickness hole of 2 mm diameter as significant change in local phase velocity from the nominal 2 m/ms. Full width at half maximum of relevant velocity profiles proved the accuracy and consistency of the damage sizing.

  13. Ramoplanin imaging conjugates--synthesis and evaluation.

    PubMed

    Sheikh, Sumbla; Sturzu, Alexander; Kalbacher, Hubert; Klose, Uwe; Nagele, Thomas; Amin, Bushra; Deeg, Martin; Horger, Marius; Ernemann, Ulrike; Heckl, Stefan

    2014-01-01

    In a previous study we found that fluorescence-marked vancomycin--a glycopeptide antibiotic--is taken up into human tumor cells. To expand on these investigations we now used the lipoglycodepsipeptide antibiotic ramoplanin. Compared to vancomycin it is not only a bigger molecule, but it also has two potential binding sites for coupling to the imaging agents. Three different ramoplanin imaging conjugates were synthesized, two used for fluorescence imaging and one for magnetic resonance imaging. The two fluorescent dyes used in confocal laser scanning microscopy (CLSM) and fluorescence activated cell sorting (FACS) were fluorescein isothiocyanate (FITC) and rhodamine isothiocyanate (RITC). The third was the magnetic resonance imaging (MRI) contrast agent gadolinium-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (GdDOTA). The uptake of ramoplanin conjugates, their specificity for different cell lines and the accessibility of the conjugates by imaging methods were evaluated on 8 human cell lines (two benign, six malignant) by CLSM, FACS and MRI experiments. Cytotoxicity of the ramoplanin conjugates was determined in the FACS experiments with the propidium iodide and Annexin-V-Fluos indicating any disruption in the cell membranes. Cytoplasmic uptake of the ramoplanin conjugates was observed in confocal laser scanning images and was measured using FACS and MRI experiments. Compared to the vancomycin conjugates the ramoplanin conjugates showed much weaker and slower uptake. Additionally, uptake of the ramoplanin conjugates led to strong membrane disruption and cell death.

  14. Evaluating fusion techniques for multi-sensor satellite image data

    SciTech Connect

    Martin, Benjamin W; Vatsavai, Raju

    2013-01-01

    Satellite image data fusion is a topic of interest in many areas including environmental monitoring, emergency response, and defense. Typically any single satellite sensor cannot provide all of the benefits offered by a combination of different sensors (e.g., high-spatial but low spectral resolution vs. low-spatial but high spectral, optical vs. SAR). Given the respective strengths and weaknesses of the different types of image data, it is beneficial to fuse many types of image data to extract as much information as possible from the data. Our work focuses on the fusion of multi-sensor image data into a unified representation that incorporates the potential strengths of a sensor in order to minimize classification error. Of particular interest is the fusion of optical and synthetic aperture radar (SAR) images into a single, multispectral image of the best possible spatial resolution. We explore various methods to optimally fuse these images and evaluate the quality of the image fusion by using K-means clustering to categorize regions in the fused images and comparing the accuracies of the resulting categorization maps.

  15. 19F Magnetic Resonance Imaging of Perfluorocarbons for the Evaluation of Response to Antibiotic Therapy in a Staphylococcus aureus Infection Model

    PubMed Central

    Jakob, Peter; Ohlsen, Knut

    2013-01-01

    Background The emergence of antibiotic resistant bacteria in recent decades has highlighted the importance of developing new drugs to treat infections. However, in addition to the design of new drugs, the development of accurate preclinical testing methods is essential. In vivo imaging technologies such as bioluminescence imaging (BLI) or magnetic resonance imaging (MRI) are promising approaches. In a previous study, we showed the effectiveness of 19F MRI using perfluorocarbon (PFC) emulsions for detecting the site of Staphylococcus aureus infection. In the present follow-up study, we investigated the use of this method for in vivo visualization of the effects of antibiotic therapy. Methods/Principal findings Mice were infected with S. aureus Xen29 and treated with 0.9% NaCl solution, vancomycin or linezolid. Mock treatment led to the highest bioluminescence values during infection followed by vancomycin treatment. Counting the number of colony-forming units (cfu) at 7 days post-infection (p.i.) showed the highest bacterial burden for the mock group and the lowest for the linezolid group. Administration of PFCs at day 2 p.i. led to the accumulation of 19F at the rim of the abscess in all mice (in the shape of a hollow sphere), and antibiotic treatment decreased the 19F signal intensity and volume. Linezolid showed the strongest effect. The BLI, cfu, and MRI results were comparable. Conclusions 19F-MRI with PFCs is an effective non-invasive method for assessing the effects of antibiotic therapy in vivo. This method does not depend on pathogen specific markers and can therefore be used to estimate the efficacy of antibacterial therapy against a broad range of clinically relevant pathogens, and to localize sites of infection. PMID:23724049

  16. Image quality evaluation of light field photography

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Zhou, Zhiliang; Yuan, Yan; Xiangli, Bin

    2011-01-01

    Light field photography captures 4D radiance information of a scene. Digital refocusing and digital correction of aberrations could be done after the photograph is taken. However, capturing 4D light field is costly and tradeoffs between different image quality metrics should be made and evaluated. This paper explores the effects of light field photography on image quality by quantitatively evaluating some basic criteria for an imaging system. A simulation approach was first developed by ray-tracing a designed light field camera. A standard testing chart followed by ISO 12233 was provided as the input scene. A sequence of light field raw images were acquired and processed by light field rendering methods afterwards. Through-focus visual resolution and MTF were calculated and analyzed. As a comparison, the same tests were taken for the same main lens system as the results of conventional photography. An experimental light field system was built up and its performance was tested. This work helps better understanding the pros and cons of light field photography in contrast with conventional imaging methods and perceiving the way to optimize the joint digital-optical design of the system.

  17. Evaluation of various deformable image registration algorithms for thoracic images.

    PubMed

    Kadoya, Noriyuki; Fujita, Yukio; Katsuta, Yoshiyuki; Dobashi, Suguru; Takeda, Ken; Kishi, Kazuma; Kubozono, Masaki; Umezawa, Rei; Sugawara, Toshiyuki; Matsushita, Haruo; Jingu, Keiichi

    2014-01-01

    We evaluated the accuracy of one commercially available and three publicly available deformable image registration (DIR) algorithms for thoracic four-dimensional (4D) computed tomography (CT) images. Five patients with esophagus cancer were studied. Datasets of the five patients were provided by DIR-lab (dir-lab.com) and consisted of thoracic 4D CT images and a coordinate list of anatomical landmarks that had been manually identified. Expert landmark correspondence was used for evaluating DIR spatial accuracy. First, the manually measured displacement vector field (mDVF) was obtained from the coordinate list of anatomical landmarks. Then the automatically calculated displacement vector field (aDVF) was calculated by using the following four DIR algorithms: B-spine implemented in Velocity AI (Velocity Medical, Atlanta, GA, USA), free-form deformation (FFD), Horn-Schunk optical flow (OF) and Demons in DIRART of MATLAB software. Registration error is defined as the difference between mDVF and aDVF. The mean 3D registration errors were 2.7 ± 0.8 mm for B-spline, 3.6 ± 1.0 mm for FFD, 2.4 ± 0.9 mm for OF and 2.4 ± 1.2 mm for Demons. The results showed that reasonable accuracy was achieved in B-spline, OF and Demons, and that these algorithms have the potential to be used for 4D dose calculation, automatic image segmentation and 4D CT ventilation imaging in patients with thoracic cancer. However, for all algorithms, the accuracy might be improved by using the optimized parameter setting. Furthermore, for B-spline in Velocity AI, the 3D registration error was small with displacements of less than ∼10 mm, indicating that this software may be useful in this range of displacements.

  18. Lung cancer: evaluation with MR imaging during and after irradiation.

    PubMed

    Yankelevitz, D F; Henschke, C I; Batata, M; Kim, Y S; Chu, F

    1994-01-01

    We used magnetic resonance (MR) imaging to evaluate treatment response of 10 consecutive lung cancer patients while they were receiving radiation therapy. Patients were scanned before treatment, during treatment, at completion of treatment, and if possible, at 3-month intervals thereafter. The initial tumor response to radiation was increasing signal intensity and increasing heterogeneity, best seen on T2-weighted images. Small tumors virtually disappeared, whereas larger masses remained as complex cystic structures or developed cavities. The adjacent irradiated lung parenchyma had increased signal on both the T1- and T2-weighted images as early as 17 days after start of treatment. The signal intensity continued to increase for several months after treatment, but subsequently decreased.

  19. Response Bias in Hospice Evaluation.

    ERIC Educational Resources Information Center

    Hayslip, Bert, Jr.; And Others

    1991-01-01

    Analyzed response bias among 34 recipients of care in hospice. Found nonrespondents to have better bereavement prognoses and tended to care for patients who were younger, male, and in program for shorter time. Nonrespondents were in contact with staff less than were respondents. Data are consistent with earlier research showing significant…

  20. Spectral response of microbolometers for hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Honniball, Casey I.; Wright, Rob; Lucey, Paul G.

    2017-02-01

    Hyperspectral imaging (HSI) is a technique with a growing list of applications and potential users, as this technique combines the power of imaging with the chemical discrimination of spectroscopy. Because HSI divides light from the scene into narrow slices of wavelength, the technique is typically thought to require cryogenic arrays to achieve the ultimate sensitivity. However, within the last two decades microbolometer arrays have improved in sensitivity, pixel count and total array area. In Hawai'i we have shown that microbolometer arrays can provide sufficient sensitivities for a variety of infrared HSI applications. The ability of microbolometer arrays to operate at ambient-temperature make them attractive candidates for low power applications, including space-based instruments on small satellites. We have two NASA projects to determine the suitability of uncooled microbolometers for HSI systems with the aim of HSI measurements from smaller satellites than is possible with cryogenic instruments. The suitability of a detector is governed in part by its spectral response. Microbolometers have wide variations in spectral response by technology and vendor, as part of our NASA projects we are conducting a spectral response measurement campaign on five different microbolometer cameras. Three of the cameras are sensitive to the long-wave infrared from 7.5 to 14 microns (two FLIR cameras and a Sofradir camera), one to the mid-wave infrared from 3 to 5 microns (LumaSense camera), and the last is sensitive to both regions from 3 to 14 microns (INO camera). Results from this campaign will be presented.

  1. An objective evaluation metric for color image fusion

    NASA Astrophysics Data System (ADS)

    Dong, Wenjie; Zheng, Yufeng

    2012-06-01

    Image fusion has been extensively studied in past two decades. By image fusion algorithms, a composite image (i.e., fused image) can be formed with several images from different sensors. The performance of image fusion methods can be assessed using subjective and/or objective measures. However, subjective evaluation involves human subjects, which significantly increases the cost of time and resource. In this paper, we will discuss objective evaluations of color image fusion algorithms. Given a reference color image and fused color images, we first convert the images into CIELab color space. Then we define four image metrics in CIELab space: the phase congruency metric (PCM), the image gradient magnitude metric (IGMM), the image contrast metric (ICM), and the color natural metric (CNM). Finally, with the four metrics, we propose an objective evaluation index (OEI) for a fused image to measure its similarity with the reference image. The larger the OEI value of a fused image is, the more similar the fused image is with the reference image. To validate the proposed metric, first the fused images are formed with different color fusion algorithms using a set of multispectral images (including visible color images, near infrared images, and long wave infrared images); and then the OEIs of fused images are calculated and compared. Experimental results show that the proposed objective evaluation index is very promising and fits well to subjective evaluation.

  2. Protection performance evaluation regarding imaging sensors hardened against laser dazzling

    NASA Astrophysics Data System (ADS)

    Ritt, Gunnar; Koerber, Michael; Forster, Daniel; Eberle, Bernd

    2015-05-01

    Electro-optical imaging sensors are widely distributed and used for many different purposes, including civil security and military operations. However, laser irradiation can easily disturb their operational capability. Thus, an adequate protection mechanism for electro-optical sensors against dazzling and damaging is highly desirable. Different protection technologies exist now, but none of them satisfies the operational requirements without any constraints. In order to evaluate the performance of various laser protection measures, we present two different approaches based on triangle orientation discrimination on the one hand and structural similarity on the other hand. For both approaches, image analysis algorithms are applied to images taken of a standard test scene with triangular test patterns which is superimposed by dazzling laser light of various irradiance levels. The evaluation methods are applied to three different sensors: a standard complementary metal oxide semiconductor camera, a high dynamic range camera with a nonlinear response curve, and a sensor hardened against laser dazzling.

  3. Performance Evaluation of a Biometric System Based on Acoustic Images

    PubMed Central

    Izquierdo-Fuente, Alberto; del Val, Lara; Jiménez, María I.; Villacorta, Juan J.

    2011-01-01

    An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two Uniform Linear Arrays (ULA) with 15 λ/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Working frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and sensors. For a case-study with 10 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. Finally, system performance, using False Match Rate (FMR)/False Non-Match Rate (FNMR) parameters and the Receiver Operating Characteristic (ROC) curve, is evaluated. On the basis of the obtained results, this system could be used for biometric applications. PMID:22163708

  4. A Ranking Method for Evaluating Constructed Responses

    ERIC Educational Resources Information Center

    Attali, Yigal

    2014-01-01

    This article presents a comparative judgment approach for holistically scored constructed response tasks. In this approach, the grader rank orders (rather than rate) the quality of a small set of responses. A prior automated evaluation of responses guides both set formation and scaling of rankings. Sets are formed to have similar prior scores and…

  5. A Ranking Method for Evaluating Constructed Responses

    ERIC Educational Resources Information Center

    Attali, Yigal

    2014-01-01

    This article presents a comparative judgment approach for holistically scored constructed response tasks. In this approach, the grader rank orders (rather than rate) the quality of a small set of responses. A prior automated evaluation of responses guides both set formation and scaling of rankings. Sets are formed to have similar prior scores and…

  6. Renal amyloidosis. Evaluation by gallium imaging

    SciTech Connect

    Lee, V.W.; Skinner, M.; Cohen, A.S.; Ngai, S.; Peng, T.T.

    1986-09-01

    A study has been performed to evaluate the efficacy of gallium imaging in the detection of renal amyloidosis. Ten of the 11 patients who had biopsy-proven renal amyloidosis demonstrated marked uptake in both kidneys. One patient revealed moderate gallium uptake in his kidneys. None of the patients had underlying renal or extrarenal pathology other than amyloidosis, which could account for renal gallium uptake (renal infection, neoplasm, hepatic failure or frequent blood transfusions). Four patients also had extrarenal foci of abnormal gallium uptake, suggesting other sites of amyloid deposits. Our data strongly suggest that gallium imaging has a high sensitivity for detection of renal amyloidosis. Its specificity is enhanced significantly by careful review of the clinical history to exclude other known causes of renal gallium uptake. Potentially, gallium imaging may be used to monitor the progress of patients under experimental therapy.

  7. An Imaging-Based Approach to the Evaluation of Xerostomia

    PubMed Central

    Duong, Steven; Youssef, Joseph; Pimenta, Paloma; Aguigam, Holly; Zhang, Jun; Calantog, Alden; Pilch, Shira; Masters, James G.; Wilder-Smith, Petra

    2014-01-01

    Background and Objective Goal was to evaluate the potential of in vivo optical coherence tomography (OCT) imaging to determine the response of patients with xerostomia to a dry mouth toothpaste versus fluoride tooth-paste placebo. Study Design/Materials and Methods Ten subjects with xerostomia participated in this double-blind, crossover, placebo-controlled study. After examination and OCT imaging, subjects used the first product for 15 days, followed by a 7-day washout period, and then they used the second product for 15 days. Data were acquired at 5-day intervals, also before and after the washout. Results Visual examination and tongue blade adhesion test did not reflect response to the product. Two imaging-based markers were identified: (i) In OCT images, epithelial thickness increased significantly (P < 0.05) after use of the dry mouth toothpaste, but did not change significantly (P > 0.05) after the use of a fluoride toothpaste and (2) Optical backscattering data showed progressive characteristic changes from baseline with use of the active product. Conclusions In this pilot study using in vivo OCT imaging, it was possible to detect and measure oral epithelial response to the dry mouth product versus placebo in patients with xerostomia. Clinical Implications This approach may permit site-specific assessment of xerostomia, individualized treatment planning and monitoring, and sequential mucosal mapping in patients with dry mouth. PMID:22693075

  8. Culturally Responsive Evaluation Meets Systems-Oriented Evaluation

    ERIC Educational Resources Information Center

    Thomas, Veronica G.; Parsons, Beverly A.

    2017-01-01

    The authors of this article each bring a different theoretical background to their evaluation practice. The first author has a background of attention to culturally responsive evaluation (CRE), while the second author has a background of attention to systems theories and their application to evaluation. Both have had their own evolution of…

  9. Culturally Responsive Evaluation Meets Systems-Oriented Evaluation

    ERIC Educational Resources Information Center

    Thomas, Veronica G.; Parsons, Beverly A.

    2017-01-01

    The authors of this article each bring a different theoretical background to their evaluation practice. The first author has a background of attention to culturally responsive evaluation (CRE), while the second author has a background of attention to systems theories and their application to evaluation. Both have had their own evolution of…

  10. Current imaging strategies for the evaluation of uterine cervical cancer

    PubMed Central

    Bourgioti, Charis; Chatoupis, Konstantinos; Moulopoulos, Lia Angela

    2016-01-01

    Uterine cervical cancer still remains an important socioeconomic issue because it largely affects women of reproductive age. Prognosis is highly depended on extent of the disease at diagnosis and, therefore, accurate staging is crucial for optimal management. Cervical cancer is clinically staged, according to International Federation of Gynecology and Obstetrics guidelines, but, currently, there is increased use of cross sectional imaging modalities [computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT)] for the study of important prognostic factors like tumor size, parametrial invasion, endocervical extension, pelvic side wall or adjacent/distal organs involvement and lymph node status. Imaging indications also include cervical cancer follow-up, evaluation of tumor response to treatment and selection of suitable candidates for less radical surgeries like radical trachelectomy for fertility preservation. The preferred imaging method for local cervical cancer evaluation is MRI; CT is equally effective for evaluation of extrauterine spread of the disease. PET-CT shows high diagnostic performance for the detection of tumor relapse and metastatic lymph nodes. The aim of this review is to familiarize radiologists with the MRI appearance of cervical carcinoma and to discuss the indications of cross sectional imaging during the course of the disease in patients with cervical carcinoma. PMID:27158421

  11. The Posterior Unstable Shoulder: Natural History, Clinical Evaluation and Imaging

    PubMed Central

    Díaz Heredia, Jorge; Ruiz Iban, Miguel Angel; Ruiz Diaz, Raquel; Moros Marco, Santos; Gutierrez Hernandez, Juan Carlos; Valencia, Maria

    2017-01-01

    Background: There is a low incidence of posterior instability which is present in only 2% to 10% of all unstable shoulders. The posterior instable shoulder includes different manifestations like fixed dislocation, recurrent subluxation or dislocation. Methods: Research and online content related to posterior instability is reviewed. Natural history, clinical evaluation and imaging are described. Results: An awareness of the disorder, together with a thoughtful evaluation, beginning with the clinical history, usually leads to proper diagnosis. An appropriate physical exam, taking in account hyperlaxity and specific tests for posterior instability should be done. Conclusion: Posterior shoulder instability is an uncommon condition and is challenging to diagnose. There is not a single injury that is responsible for all cases of recurrent shoulder dislocation or subluxation, and the presence of soft tissue lesions or bone alterations should be evaluated, with the use of adequate simple radiology and multiplanar imaging.

  12. Series: Practical Evaluation of Clinical Image Quality (4): Determination of Image Quality in Digital Radiography System.

    PubMed

    Katayama, Reiji

    Recently, for medical imaging, digital radiography systems are widely used in clinical practices. However, a study in the past reported that a patient radiation exposure level by digital radiography is in fact not lower than that by analog radiography system. High level of attention needs to be paid for over-exposure when using the conventional analog radiography with a screen and a film, as it results in high density of the film. However, for digital radiography systems, since the automatic adjusting function of image density is equipped with them, no attention for radiation dose need to be paid. Thus technologists tend to be careless and results in higher chance for over-exposure. Current digital radiography systems are high-performance in the image properties and capable of patient dose reduction. Especially, the image quality of the flat panel detector system is recognized, higher than that of the computed radiography system by imaging plates, in both objective and subjective evaluations. Therefore, we technologists are responsible for optimizing the balance between the image quality of the digital radiogram and the radiation dose required for each case. Moreover, it is also required for us as medical technologists to make effective use of such evaluation result of medical images for patients.

  13. [Acute response of right ventricular function to iloprost inhalations in patients with pulmonary arterial hypertension: preliminary evaluation 
with cardiac magnetic resonance imaging].

    PubMed

    Lu, Qingqing; Li, Dong; Yang, Zhenwen; Han, Yan; Cui, Qian; Zhang, Zhang; Yu, Tielian

    2015-03-01

    背景与目的 肺动脉高压(pulmonary arterial hypertension, PAH)是以肺循环压力异常增高为特征的进展性疾病,可引起右心室(right ventricle, RV)功能进行性衰竭,最终导致死亡。因此RV功能的评估在PAH的诊断、随访中起着重要作用。心脏磁共振成像(cardiac magnetic resonance imaging, CMRI)成为无创评价心室功能的参照标准,尤其是RV功能。本研究通过CMRI评估吸入伊洛前列素对PAH患者RV功能影响的即刻效应。方法 2012年3月-2014年3月PAH患者48例,吸入单剂量20 μg的伊洛前列素溶液前、后立即进行CMRI检查,测量RV的舒张末期容积(end-diastolic volume, EDV)、收缩末期容积(end-systolic volume, ESV)、每搏输出量(stroke volume, SV)、射血分数(ejection fraction, EF)、心输出量(cardiac output, CO)、舒张末期面积(end-diastolic area, EDA)及收缩末期面积(end-systolic area, ESA)。RV面积变化百分比(percentage of RV area change, %RVAC)由公式[%RVAC=(EDA-ESA)/EDA×100%]计算获得。采用Wilcoxon符号秩和检验或配对t检验分析吸入伊洛前列素前、后RV功能参数变化。P<0.05为差异有统计学意义。结果 吸入伊洛前列素后,患者的RV功能改善,RV EDV、RV ESV显著下降(P=0.007, P<0.001),RV SV、RV EF及%RVAC增加(P=0.014, P=0.009, P=0.006),RV CO无变化(P=0.851)。结论 吸入伊洛前列素能立即明显改善PAH患者的RV功能,CMRI能准确、无创地评估该即刻效应。.

  14. Series: Practical Evaluation of Clinical Image Quality (3): Subjective Evaluation of Image Quality in Digital Radiography Systems.

    PubMed

    Katayama, Reiji

    In the environment of picture archiving and communication system (PACS), the subjective evaluation of medical image quality is performed using an image display monitor. Commonly, PACS and its image viewer can handle digital imaging and communications in medicine (DICOM) format image files that are displayed as 8-bit grayscale images in the monitor. However, the original grayscale of DICOM image is between 10-bit to 16-bit depth. Therefore, in order for DICOM images to be displayed in the monitor by PACS image viewer, they need to be converted into 8-bit depth grayscale. This conversion indicates that the original characteristics of DICOM images are altered when they are displayed in the monitor by PACS image viewer. Moreover, image data interpolation to match the image matrix for the resolution of the monitor also alters the characteristics of images. For these reasons, it is a must to recognize the influential factors of image display settings for the subjective evaluation of medical image quality.

  15. Hyperspectral and multispectral imaging for evaluating food safety and quality

    USDA-ARS?s Scientific Manuscript database

    Spectral imaging technologies have been developed rapidly during the past decade. This paper presents hyperspectral and multispectral imaging technologies in the area of food safety and quality evaluation, with an introduction, demonstration, and summarization of the spectral imaging techniques avai...

  16. Evaluation of Deconvolution Methods for PRISM Images

    NASA Astrophysics Data System (ADS)

    Schwind, Peter; Palubinskas, Gintautas; Storch, Tobias; Muller, Rupert

    2008-11-01

    Within the scope of a project by the European Space Agency (ESA), the German Aerospace Center (DLR) is responsible for the establishment of prototype processors for ALOS/AVNIR-2 and ALOS/PRISM data. This processing chain not only includes radiometric and geometric correction for ALOS/AVNIR-2 and ALOS/PRISM but also atmospheric correction for ALOS/AVNIR-2. In addition to that an optional deconvolution step for the ALOS/PRISM data is offered to improve the image quality. This paper gives a short introduction into the processing chain as a whole and a more in-depth look into the deconvolution strategies taken into consideration for ALOS/PRISM images.

  17. Boundary overlap for medical image segmentation evaluation

    NASA Astrophysics Data System (ADS)

    Yeghiazaryan, Varduhi; Voiculescu, Irina

    2017-03-01

    All medical image segmentation algorithms need to be validated and compared, and yet no evaluation framework is widely accepted within the imaging community. Collections of segmentation results often need to be compared and ranked by their effectiveness. Evaluation measures which are popular in the literature are based on region overlap or boundary distance. None of these are consistent in the way they rank segmentation results: they tend to be sensitive to one or another type of segmentation error (size, location, shape) but no single measure covers all error types. We introduce a new family of measures, with hybrid characteristics. These measures quantify similarity/difference of segmented regions by considering their overlap around the region boundaries. This family is more sensitive than other measures in the literature to combinations of segmentation error types. We compare measure performance on collections of segmentation results sourced from carefully compiled 2D synthetic data, and also on 3D medical image volumes. We show that our new measure: (1) penalises errors successfully, especially those around region boundaries; (2) gives a low similarity score when existing measures disagree, thus avoiding overly inflated scores; and (3) scores segmentation results over a wider range of values. We consider a representative measure from this family and the effect of its only free parameter on error sensitivity, typical value range, and running time.

  18. A versatile nondestructive evaluation imaging workstation

    NASA Technical Reports Server (NTRS)

    Chern, E. James; Butler, David W.

    1994-01-01

    Ultrasonic C-scan and eddy current imaging systems are of the pointwise type evaluation systems that rely on a mechanical scanner to physically maneuver a probe relative to the specimen point by point in order to acquire data and generate images. Since the ultrasonic C-scan and eddy current imaging systems are based on the same mechanical scanning mechanisms, the two systems can be combined using the same PC platform with a common mechanical manipulation subsystem and integrated data acquisition software. Based on this concept, we have developed an IBM PC-based combined ultrasonic C-scan and eddy current imaging system. The system is modularized and provides capacity for future hardware and software expansions. Advantages associated with the combined system are: (1) eliminated duplication of the computer and mechanical hardware, (2) unified data acquisition, processing and storage software, (3) reduced setup time for repetitious ultrasonic and eddy current scans, and (4) improved system efficiency. The concept can be adapted to many engineering systems by integrating related PC-based instruments into one multipurpose workstation such as dispensing, machining, packaging, sorting, and other industrial applications.

  19. A versatile nondestructive evaluation imaging workstation

    NASA Astrophysics Data System (ADS)

    Chern, E. James; Butler, David W.

    1994-02-01

    Ultrasonic C-scan and eddy current imaging systems are of the pointwise type evaluation systems that rely on a mechanical scanner to physically maneuver a probe relative to the specimen point by point in order to acquire data and generate images. Since the ultrasonic C-scan and eddy current imaging systems are based on the same mechanical scanning mechanisms, the two systems can be combined using the same PC platform with a common mechanical manipulation subsystem and integrated data acquisition software. Based on this concept, we have developed an IBM PC-based combined ultrasonic C-scan and eddy current imaging system. The system is modularized and provides capacity for future hardware and software expansions. Advantages associated with the combined system are: (1) eliminated duplication of the computer and mechanical hardware, (2) unified data acquisition, processing and storage software, (3) reduced setup time for repetitious ultrasonic and eddy current scans, and (4) improved system efficiency. The concept can be adapted to many engineering systems by integrating related PC-based instruments into one multipurpose workstation such as dispensing, machining, packaging, sorting, and other industrial applications.

  20. Comparative effectiveness of imaging modalities to determine metastatic breast cancer treatment response.

    PubMed

    Lee, Christoph I; Gold, Laura S; Nelson, Heidi D; Chou, Roger; Ramsey, Scott D; Sullivan, Sean D

    2015-02-01

    We performed a systematic review to address the comparative effectiveness of different imaging modalities in evaluating treatment response among metastatic breast cancer patients. We searched seven multidisciplinary electronic databases for relevant publications (January 2003-December 2013) and performed dual abstraction of details and results for all clinical studies that involved stage IV breast cancer patients and evaluated imaging for detecting treatment response. Among 159 citations reviewed, 17 single-institution, non-randomized, observational studies met our inclusion criteria. Several studies demonstrate that changes in PET/CT standard uptake values are associated with changes in tumor volume as determined by bone scan, MRI, and/or CT. However, no studies evaluated comparative test performance between modalities or determined relationships between imaging findings and subsequent clinical decisions. Evidence for imaging's effectiveness in determining treatment response among metastatic breast cancer patients is limited. More rigorous research is needed to address imaging's value in this patient population.

  1. Response Evaluation in Computer Based Tutorials.

    ERIC Educational Resources Information Center

    Smyth, Timothy

    1987-01-01

    Describes a computer program that allows undergraduate students to undertake nomenclature tutorials in organic chemistry, where user response is evaluated based on a set of rules that determine appropriate feedback. Design of the software is described, including the use of computer graphics, and results of students' evaluations are briefly…

  2. Evaluation of imaging characteristics in CTDI phantom size on contrast imaging

    NASA Astrophysics Data System (ADS)

    Jeon, Pil-Hyun; Lee, Won-Hyung; Jeon, Seong-Su; Kim, Hee-Joung

    2015-03-01

    Recently, there have been several physics and clinical studies on the use of lower tube potentials in CT imaging, with the purpose of improving image quality or further reducing radiation dose. We investigated an experimental study using a series of different sized, polymethyl methacrylate (PMMA) phantoms, demonstrating the potential strategy for dose reduction and to distinguish component of plaque by imaging their energy responses using CT. We investigated the relationship between different sizes of cylinderic PMMA-equivalent phantoms with diameter of 12, 16, 20, 24, and 32 cm and used contrast at various tube voltages (80, 100, 120, and 140 kVp) using a 16-detector row CT scanner. The contrast represented CT numbers as different materials for the water, calcium chloride, and iodine. Phantom insertions also allow quantitative measures of image noise, contrast, contrast-to-noise ratio (CNR) and figure of merit (FOM). When evaluating FOM, it was found that the lower kVp provided the better CNR. An experimental study was performed to demonstrate reduced dose for both dose efficient and practical feasibility for different patient sizes and diagnostic tasks by relating achievable CNR and the volume CT dose index (CTDIvol). The use of spectra optimized to the specific application could provide further improvements of distinguishing iodine, calcium and plaque component for patient size. The purpose of this study was to evaluate variations in image noise and contrast using different tube potentials in a CTDI phantom on contrast imaging.

  3. Use of Responsive Evaluation in Statewide Program Evaluation

    ERIC Educational Resources Information Center

    Kalman, Marjorie

    1976-01-01

    A summer school program stressing basic skills for migrant children in a rural Illinois community was assessed according to Stake's responsive evaluation model. Informal communication, program activities, audience needs, and participant values were emphasized in this case study. This evaluation method provided useful information for the state's…

  4. Use of Responsive Evaluation in Statewide Program Evaluation.

    ERIC Educational Resources Information Center

    Kalman, Marjorie

    The objective of this paper is to discuss the utilization of Stake's theory of responsive evaluation by a unit in state government charged with the evaluation of the Illinois Migrant Program. Through interviews with state and local Title I staff, we were able to discover program purposes and concerns and to later conceptualize these concerns into…

  5. Techniques to evaluate the quality of medical images

    NASA Astrophysics Data System (ADS)

    Perez-Diaz, Marlen

    2014-11-01

    There is not a perfect agree in the definition of medical image quality from the physician and physicist point of view. The present conference analyzes the standard techniques used to grade image quality. In the first place, an analysis about how viewing conditions related to environment, monitor used or physician experience determines the subjective evaluation is done. After that, the physics point of view is analyzed including the advantage and disadvantage of the main published methods like: Quality Control Tests, Mathematical metrics, Modulation Transfer Function, Noise Power Spectrum, System Response Curve and Mathematical observers. Each method is exemplified with the results of updated papers. We concluded that the most successful methods up to the present have been those which include simulations of the Human Visual System. They have good correlation between the results of the objective metrics and the subjective evaluation made by the observers.

  6. Evaluation of treatment response and resistance in metastatic renal cell cancer (mRCC) using integrated (18)F-Fluorodeoxyglucose ((18)F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI); The REMAP study.

    PubMed

    Kelly-Morland, Christian; Rudman, Sarah; Nathan, Paul; Mallett, Susan; Montana, Giovanni; Cook, Gary; Goh, Vicky

    2017-06-02

    Tyrosine kinase inhibitors are the first line standard of care for treatment of metastatic renal cell carcinoma (RCC). Accurate response assessment in the setting of antiangiogenic therapies remains suboptimal as standard size-related response criteria do not necessarily accurately reflect clinical benefit, as they may be less pronounced or occur later in therapy than devascularisation. The challenge for imaging is providing timely assessment of disease status allowing therapies to be tailored to ensure ongoing clinical benefit. We propose that combined assessment of morphological, physiological and metabolic imaging parameters using 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ((18)F-FDG PET/MRI) will better reflect disease behaviour, improving assessment of response/non-response/relapse. The REMAP study is a single-centre prospective observational study. Eligible patients with metastatic renal cell carcinoma, planned for systemic therapy, with at least 2 lesions will undergo an integrated (18)F-FDG PET and MRI whole body imaging with diffusion weighted and contrast-enhanced multiphasic as well as standard anatomical MRI sequences at baseline, 12 weeks and 24 weeks of systemic therapy allowing (18)F-FDG standardised uptake value (SUV), apparent diffusion co-efficient (ADC) and normalised signal intensity (SI) parameters to be obtained. Standard of care contrast-enhanced computed tomography CT scans will be performed at equivalent time-points. CT response categorisation will be performed using RECIST 1.1 and alternative (modified)Choi and MASS criteria. The reference standard for disease status will be by consensus panel taking into account clinical, biochemical and conventional imaging parameters. Intra- and inter-tumoural heterogeneity in vascular, diffusion and metabolic response/non-response will be assessed by image texture analysis. Imaging will also inform the development of computational methods for automated disease

  7. Hyperspectral range imaging for transportation systems evaluation

    NASA Astrophysics Data System (ADS)

    Bridgelall, Raj; Rafert, J. B.; Atwood, Don; Tolliver, Denver D.

    2016-04-01

    Transportation agencies expend significant resources to inspect critical infrastructure such as roadways, railways, and pipelines. Regular inspections identify important defects and generate data to forecast maintenance needs. However, cost and practical limitations prevent the scaling of current inspection methods beyond relatively small portions of the network. Consequently, existing approaches fail to discover many high-risk defect formations. Remote sensing techniques offer the potential for more rapid and extensive non-destructive evaluations of the multimodal transportation infrastructure. However, optical occlusions and limitations in the spatial resolution of typical airborne and space-borne platforms limit their applicability. This research proposes hyperspectral image classification to isolate transportation infrastructure targets for high-resolution photogrammetric analysis. A plenoptic swarm of unmanned aircraft systems will capture images with centimeter-scale spatial resolution, large swaths, and polarization diversity. The light field solution will incorporate structure-from-motion techniques to reconstruct three-dimensional details of the isolated targets from sequences of two-dimensional images. A comparative analysis of existing low-power wireless communications standards suggests an application dependent tradeoff in selecting the best-suited link to coordinate swarming operations. This study further produced a taxonomy of specific roadway and railway defects, distress symptoms, and other anomalies that the proposed plenoptic swarm sensing system would identify and characterize to estimate risk levels.

  8. Algorithms evaluation for fundus images enhancement

    NASA Astrophysics Data System (ADS)

    Braem, V.; Marcos, M.; Bizai, G.; Drozdowicz, B.; Salvatelli, y. A.

    2011-12-01

    Color images of the retina inherently involve noise and illumination artifacts. In order to improve the diagnostic quality of the images, it is desirable to homogenize the non-uniform illumination and increase contrast while preserving color characteristics. The visual result of different pre-processing techniques can be very dissimilar and it is necessary to make an objective assessment of the techniques in order to select the most suitable. In this article the performance of eight algorithms to correct the non-uniform illumination, contrast modification and color preservation was evaluated. In order to choose the most suitable a general score was proposed. The results got good impression from experts, although some differences suggest that not necessarily the best statistical quality of image is the one of best diagnostic quality to the trained doctor eye. This means that the best pre-processing algorithm for an automatic classification may be different to the most suitable one for visual diagnosis. However, both should result in the same final diagnosis.

  9. Measured responsivities of generation II and hybrid image intensifiers

    SciTech Connect

    Yates, G.J.; King, N.S.P.; Thomas, M.C.

    1995-07-01

    We have measured the absolute and coupled system responsivities of several image intensifier types at several wavelengths in the visible spectrum. Intensifiers characterized include microchannel plate (MCP) generation II proximity-focused and hybrid generation I/generation II electrostatic-focused designs. Configurations including single plate, double plate, nominal and high strip current MCPs, and standard S20 and super generation II enhanced S-20 photocathodes were evaluated. Absolute responsivity measurements were performed using NIST-traceable radiometry instrumentation. The normalized relative sensitivities and overall optical luminous gain performance provided by individual intensifiers when similarly coupled to either high resolution 10-bit RS-170 CCD or FPS cameras are presented along with their radiometric data.

  10. University Social Responsibility and Brand Image of Private Universities in Bangkok

    ERIC Educational Resources Information Center

    Plungpongpan, Jirawan; Tiangsoongnern, Leela; Speece, Mark

    2016-01-01

    Purpose: The purpose of this paper is to examine the effects of university social responsibility (USR) on the brand image of private universities in Thailand. Brand image is important for entry into the consideration set as prospective students evaluate options for university study. USR activities may be implicit or explicit, i.e., actively…

  11. University Social Responsibility and Brand Image of Private Universities in Bangkok

    ERIC Educational Resources Information Center

    Plungpongpan, Jirawan; Tiangsoongnern, Leela; Speece, Mark

    2016-01-01

    Purpose: The purpose of this paper is to examine the effects of university social responsibility (USR) on the brand image of private universities in Thailand. Brand image is important for entry into the consideration set as prospective students evaluate options for university study. USR activities may be implicit or explicit, i.e., actively…

  12. Lateral hip pain: does imaging predict response to localized injection?

    PubMed

    Walker, Peter; Kannangara, Siri; Bruce, Warwick J M; Michael, Dean; Van der Wall, H

    2007-04-01

    Lateral hip pain is a common complaint in patients with a history of lower back pain from spinal disease. These patients often are diagnosed and treated for trochanteric bursitis because of localized pain and tenderness in the lateral hip. We presumed numerous scintigraphic features could provide diagnostic criteria for diagnosing gluteus medius tendinitis and trochanteric bursitis. A study was designed to assess the scintigraphic criteria for diagnosis of trochanteric bursitis and to evaluate the relationship of trochanteric bursitis to gluteus medius tendinitis and lumbar degenerative disease in predicting relapse after injection. We evaluated 97 patients with greater trochanteric pain syndrome to find a correlation between trochanteric bursitis, gluteus medius tendinitis, and spinal degenerative disease using scintigraphy and magnetic resonance imaging. We also evaluated predictors for responding to trochanteric injection of local anesthetic/glucocorticoid injection. We found a correlation between lumbar degenerative disease, gluteus medius tendinopathy, and trochanteric bursitis. Of these, 30 of 48 patients (63%) responded to injection of local anesthetic and glucocorticoids. The major predictor of relapse of pain after injection in 18 patients was the presence of moderate to severe lumbar degenerative disease seen on scintigraphic imaging. We propose a mechanistic model of the greater trochanteric pain syndrome to explain the interrelationship and response to therapy. Scintigraphy can provide sensitive and specific diagnoses of gluteus medius tendinitis and trochanteric bursitis.

  13. The simulation of adaptive optical image even and pulse noise and research of image quality evaluation

    NASA Astrophysics Data System (ADS)

    Wen, Changli; Xu, Yuannan; Xu, Rong; Liu, Changhai; Men, Tao; Niu, Wei

    2013-09-01

    As optical image becomes more and more important in adaptive optics area, and adaptive optical telescopes play a more and more important role in the detection system on the ground, and the images we get are so many that we need find a suitable method to choose good quality images automatically in order to save human power, people pay more and more attention in image's evaluation methods and their characteristics. According to different image degradation model, the applicability of different image's quality evaluation method will be different. Researchers have paid most attention in how to improve or build new method to evaluate degraded images. Now we should change our way to take some research in the models of degradation of images, the reasons of image degradation, and the relations among different degraded images and different image quality evaluation methods. In this paper, we build models of even noise and pulse noise based on their definition and get degraded images using these models, and we take research in six kinds of usual image quality evaluation methods such as square error method, sum of multi-power of grey scale method, entropy method, Fisher function method, Sobel method, and sum of grads method, and we make computer software for these methods to use easily to evaluate all kinds of images input. Then we evaluate the images' qualities with different evaluation methods and analyze the results of six kinds of methods, and finally we get many important results. Such as the characteristics of every method for evaluating qualities of degraded images of even noise, the characteristics of every method for evaluating qualities of degraded images of pulse noise, and the best method to evaluate images which affected by tow kinds of noise both and the characteristics of this method. These results are important to image's choosing automatically, and this will help we to manage the images we get through adaptive optical telescopes base on the ground.

  14. Pupil responses to high-level image content.

    PubMed

    Naber, Marnix; Nakayama, Ken

    2013-05-17

    The link between arousal and pupil dilation is well studied, but it is less known that other cognitive processes can trigger pupil responses. Here we present evidence that pupil responses can be induced by high-level scene processing, independent of changes in low-level features or arousal. In Experiment 1, we recorded changes in pupil diameter of observers while they viewed a variety of natural scenes with or without a sun that were presented either upright or inverted. Image inversion had the strongest effect on the pupil responses. The pupil constricted more to the onset of upright images as compared to inverted images. Furthermore, the amplitudes of pupil constrictions to viewing images containing a sun were larger relative to control images. In Experiment 2, we presented cartoon versions of upright and inverted pictures that included either a sun or a moon. The image backgrounds were kept identical across conditions. Similar to Experiment 1, upright images triggered pupil constrictions with larger amplitudes than inverted images and images of the sun evoked greater pupil contraction than images of the moon. We suggest that the modulations of pupil responses were due to higher-level interpretations of image content.

  15. Fuzzy Index to Evaluate Edge Detection in Digital Images.

    PubMed

    Perez-Ornelas, Felicitas; Mendoza, Olivia; Melin, Patricia; Castro, Juan R; Rodriguez-Diaz, Antonio; Castillo, Oscar

    2015-01-01

    In literature, we can find different metrics to evaluate the detected edges in digital images, like Pratt's figure of merit (FOM), Jaccard's index (JI) and Dice's coefficient (DC). These metrics compare two images, the first one is the reference edges image, and the second one is the detected edges image. It is important to mention that all existing metrics must binarize images before their evaluation. Binarization step causes information to be lost because an incomplete image is being evaluated. In this paper, we propose a fuzzy index (FI) for edge evaluation that does not use a binarization step. In order to process all detected edges, images are represented in their fuzzy form and all calculations are made with fuzzy sets operators and fuzzy Euclidean distance between both images. Our proposed index is compared to the most used metrics using synthetic images, with good results.

  16. Fuzzy Index to Evaluate Edge Detection in Digital Images

    PubMed Central

    Perez-Ornelas, Felicitas; Mendoza, Olivia; Melin, Patricia; Castro, Juan R.; Rodriguez-Diaz, Antonio; Castillo, Oscar

    2015-01-01

    In literature, we can find different metrics to evaluate the detected edges in digital images, like Pratt's figure of merit (FOM), Jaccard’s index (JI) and Dice’s coefficient (DC). These metrics compare two images, the first one is the reference edges image, and the second one is the detected edges image. It is important to mention that all existing metrics must binarize images before their evaluation. Binarization step causes information to be lost because an incomplete image is being evaluated. In this paper, we propose a fuzzy index (FI) for edge evaluation that does not use a binarization step. In order to process all detected edges, images are represented in their fuzzy form and all calculations are made with fuzzy sets operators and fuzzy Euclidean distance between both images. Our proposed index is compared to the most used metrics using synthetic images, with good results. PMID:26115362

  17. Physiological imaging of electrical trauma and therapeutic responses

    NASA Astrophysics Data System (ADS)

    Chen, Chin-Tu; Matthews, K.; Aarsvold, John N.; Mintzer, Robert A.; Yasillo, Nicholas J.; Hannig, Jurgen; Capelli-Schellpfefer, M.; Cooper, Malcolm; Lee, Raphael C.

    2000-04-01

    In victims of electrical trauma, electroporation of cell membrane, in which lipid bilayer is permeabilized by thermal and electrical forces, is thought to be a substantial cause of tissue damage. It has been suggested that certain mild surfactant in low concentration could induce sealing of permeabilized lipid bilayers, thus repairing cell membranes that had not been extensively damaged. With an animal model of electrically injured hind limb of rats, we have demonstrated and validated the use of radiotracer imaging technique to assess the physiology of the damaged tissues after electrical shock and of their repairs after applying surfactant as a therapeutic strategy. For example, using Tc-99m labeled pyrophosphate (PYP), which follows calcium in cellular function and is known to accumulate in damaged tissues, we have established a physiological imaging approach for assessment of the extent of tissue injury for diagnosis and surgical planning, as well as for evaluation of responses to therapy. With the use of a small, hand-held, miniature gamma camera, this physiological imaging method can be employed at patient's bedside and even in the field, for example, at accident site or during transfer for emergency care, rapid diagnosis, and prompt treatment in order to maximize the chance for tissue survival.

  18. Positron autoradiography for intravascular imaging: feasibility evaluation

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-01

    Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and

  19. Positron autoradiography for intravascular imaging: feasibility evaluation.

    PubMed

    Shikhaliev, Polad M; Xu, Tong; Ducote, Justin L; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-21

    Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and

  20. Vibration response imaging: protocol for a systematic review

    PubMed Central

    2013-01-01

    Background The concept of lung sounds conveying information regarding lung physiology has been used extensively in clinical practice, particularly with physical auscultation using a stethoscope. Advances in computer technology have facilitated the construction of dynamic visual images derived from recorded lung sounds. Arguably, the most significant progress in this field was the development of the commercially available vibration response imaging (VRI) (Deep Breeze Ltd, Or-Akiva, Israel). This device provides a non-invasive, dynamic image of both lungs constructed from sounds detected from the lungs using surface sensors. In the literature, VRI has been utilized in a multitude of clinical and research settings. This systematic review aims to address three study questions relating to whether VRI can be used as an evaluative device, whether the images generated can be characterized, and which tools and measures have been used to assess these images. Methods/Design This systematic review will involve implementing search strategies in five online journal databases in order to extract articles relating to the application of VRI. Appropriate articles will be identified against a set of pre-determined eligibility criteria and assessed for methodological quality using a standardized scale. Included articles will have data extracted by the reviewers using a standardized evidence table. A narrative synthesis based on a standardized framework will be conducted, clustering evidence into three main groups; one for each of the study questions. A meta-analysis will be conducted if two or more research articles meet pre-determined criteria that allow quantitative synthesis to take place. Discussion This systematic review aims to provide a complete overview of the scope of VRI in the clinical and research settings, as well as to discuss methods to interpret the data obtained from VRI. The systematic review intends to help clinicians to make informed decisions on the clinical

  1. Hemodynamic responses to functional activation accessed by optical imaging

    NASA Astrophysics Data System (ADS)

    Ni, Songlin; Li, Pengcheng; Yang, Yuanyuan; Lv, Xiaohua; Luo, Qingming

    2006-01-01

    A multi-wavelength light-emitting diode (LED) and laser diode (LD) based optical imaging system was developed to visualize the changes in cerebral blood flow, oxygenation following functional activation simultaneously in rodent cortex. The 2-D blood flow image was accessed by laser speckle contrast imaging, and the spectroscopic imaging of intrinsic signal was used for the calculation of oxyhemoglobin (HbO), deoxyhemoglobin (Hb) and total hemoglobin (HbT) concentration. The combination of spectroscopic imaging and laser speckle contrast imaging provides the capability to simultaneously investigate the spatial and temporal blood flow and hemoglobin concentration changes with high resolution, which may lead to a better understanding of the coupling between neuronal activation and vascular responses. The optical imaging system been built is compact and convenient to investigators. And it is reliable to acquire raw data. In present study, the hemodynamic responses to cortical spreading depression (CSD) in parietal cortex of ~-chloralose/urethan anesthetized rats were demonstrated.

  2. Medical image database for software and algorithm evaluation

    NASA Astrophysics Data System (ADS)

    dos Santos, Marcelo; Furuie, Sergio S.

    2005-04-01

    This work presents the development of a framework to make available a free, online, multipurpose and multimodality medical image database for software and algorithm evaluation. We have implemented a distributed architecture for medical image database, including authoring, storage, and repository for documents and image processing software. The system aims to offer a complete test bed and a set of resources including software, link to scientific papers, gold standards, reference images and post-processed images, enabling medical image processing community (scientists, physicians, students and industrials) to be more aware of evaluation issues. Our focus of development was on convenience and easy of use of a generic system adaptable to different contexts.

  3. Evaluating glaucoma damage: emerging imaging technologies

    PubMed Central

    Kostanyan, Tigran; Wollstein, Gadi; Schuman, Joel S

    2015-01-01

    The use of ocular imaging tools to estimate structural and functional damage in glaucoma has become a common clinical practice and a substantial focus of vision research. The evolution of the imaging technologies through increased scanning speed, penetration depth, image registration and development of multimodal devices has the potential to detect the pathology more reliably and in earlier stages. This review is focused on new ocular imaging modalities used for glaucoma diagnosis. PMID:27087829

  4. Image Familiarization Sharpens Response Dynamics of Neurons in Inferotemporal Cortex

    PubMed Central

    Meyer, Travis; Walker, Christopher; Cho, Raymond Y.; Olson, Carl R.

    2015-01-01

    Repeated viewing of an image over days and weeks induces a marked reduction in the strength with which neurons in monkey inferotemporal cortex respond to it. The processing advantage that attaches to this reduction is unknown. One possibility is that truncation of the response to a familiar image leaves neurons in a state of readiness to respond to ensuing images and thus enhances their ability to track rapidly changing displays. We have explored this possibility by assessing neuronal responses to familiar and novel images in rapid serial visual displays. Inferotemporal neurons respond more strongly to familiar than to novel images in such displays. The effect is stronger among putative inhibitory neurons than among putative excitatory neurons. A comparable effect occurs at the level of the scalp potential in humans. We conclude that long-term familiarization sharpens the response dynamics of neurons in both monkey and human extrastriate visual cortex. PMID:25151263

  5. Finger vein image quality evaluation using support vector machines

    NASA Astrophysics Data System (ADS)

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-02-01

    In an automatic finger-vein recognition system, finger-vein image quality is significant for segmentation, enhancement, and matching processes. In this paper, we propose a finger-vein image quality evaluation method using support vector machines (SVMs). We extract three features including the gradient, image contrast, and information capacity from the input image. An SVM model is built on the training images with annotated quality labels (i.e., high/low) and then applied to unseen images for quality evaluation. To resolve the class-imbalance problem in the training data, we perform oversampling for the minority class with random-synthetic minority oversampling technique. Cross-validation is also employed to verify the reliability and stability of the learned model. Our experimental results show the effectiveness of our method in evaluating the quality of finger-vein images, and by discarding low-quality images detected by our method, the overall finger-vein recognition performance is considerably improved.

  6. Children's response to their true and distorted mirror images.

    PubMed

    Modarressi, T; Kenny, T

    1977-01-01

    In order to study the development of body image, 16 children aged 2 months to 8 years were tested to determine their levels of cognitive development on the basis of Piaget's theory, and their responses to their true and distorted mirror images. The study indicates a definite characteristic response by children according to their levels of cognitive development. This corresponds to infantile anxieties appropriate to the psychoanalytic theory of object relationships. The theoretical and clinical implications of the study are discussed.

  7. Evaluation of lung tumor response to therapy: Current and emerging techniques.

    PubMed

    Coche, E

    2016-10-01

    Lung tumor response to therapy may be evaluated in most instances by morphological criteria such as RECIST 1.1 on computed tomography (CT) or magnetic resonance imaging (MRI). However, those criteria are limited because they are based on tumoral dimensional changes and do not take into account other morphologic criteria such as density evaluation, functional or metabolic changes that may occur following conventional or targeted chemotherapy. New techniques such as dual-energy CT, PET-CT, MRI including diffusion-weighted MRI has to be considered into the new technical armamentarium for tumor response evaluation. Integration of all informations provided by the different imaging modalities has to be integrated and represents probably the future goal of tumor response evaluation. The aim of the present paper is to review the current and emerging imaging criteria used to evaluate the response of therapy in the field of lung cancer.

  8. Comprehensive evaluation for fused images of multispectral and panchromatic images based on entropy weight method

    NASA Astrophysics Data System (ADS)

    Xia, Xiaojie; Yuan, Yan; Su, Lijuan; Hu, Liang

    2016-09-01

    An evaluation model of image fusion based on entropy weight method is put forward to resolve evaluation issue for fused results of multispectral and panchromatic images, such as the lack of overall importance in single factor metric evaluation and the discrepancy among different categories of characteristic evaluation. In this way, several single factor metrics in different aspects of image are selected to form a metric set, then the entropy weights for each single factor index are calculated based on entropy weight method, thus a new comprehensive evaluation index is obtained to evaluate each fused image and images with higher spectral resolution and spatial resolution can be acquired. Experimental analysis shows that the proposed method is of versatility, objectivity and rationality and performs well on the evaluation of fused results of multispectral and panchromatic images.

  9. Evaluation of improvement of diffuse optical imaging of brain function by high-density probe arrangements and imaging algorithms

    NASA Astrophysics Data System (ADS)

    Sakakibara, Yusuke; Kurihara, Kazuki; Okada, Eiji

    2016-04-01

    Diffuse optical imaging has been applied to measure the localized hemodynamic responses to brain activation. One of the serious problems with diffuse optical imaging is the limitation of the spatial resolution caused by the sparse probe arrangement and broadened spatial sensitivity profile for each probe pair. High-density probe arrangements and an image reconstruction algorithm considering the broadening of the spatial sensitivity can improve the spatial resolution of the image. In this study, the diffuse optical imaging of the absorption change in the brain is simulated to evaluate the effect of the high-density probe arrangements and imaging methods. The localization error, equivalent full-width half maximum and circularity of the absorption change in the image obtained by the mapping and reconstruction methods from the data measured by five probe arrangements are compared to quantitatively evaluate the imaging methods and probe arrangements. The simple mapping method is sufficient for the density of the measurement points up to the double-density probe arrangement. The image reconstruction method considering the broadening of the spatial sensitivity of the probe pairs can effectively improve the spatial resolution of the image obtained from the probe arrangements higher than the quadruple density, in which the distance between the neighboring measurement points is 10.6 mm.

  10. Imaging of non-Hodgkin lymphomas: diagnosis and response-adapted strategies.

    PubMed

    El-Galaly, Tarec Christoffer; Hutchings, Martin

    2015-01-01

    Optimal lymphoma management requires accurate pretreatment staging and reliable assessment of response, both during and after therapy. Positron emission tomography with computerized tomography (PET/CT) combines functional and anatomical imaging and provides the most sensitive and accurate methods for lymphoma imaging. New guidelines for lymphoma imaging and recently revised criteria for lymphoma staging and response assessment recommend PET/CT staging, treatment monitoring, and response evaluation in all FDG-avid lymphomas, while CT remains the method of choice for non-FDG-avid histologies. Since interim PET imaging has high prognostic value in lymphoma, a number of trials investigate PET-based, response-adapted therapy for non-Hodgkin lymphomas (NHL). PET response is the main determinant of response according to the new response criteria, but PET/CT has little or no role in routine surveillance imaging, the value which is itself questionable. This review presents from a clinical point of view the evidence for the use of imaging and primarily PET/CT in NHL before, during, and after therapy. The reader is given an overview of the current PET-based interventional NHL trials and an insight into possible future developments in the field, including new PET tracers.

  11. Elbow magnetic resonance imaging: imaging anatomy and evaluation.

    PubMed

    Hauptfleisch, Jennifer; English, Collette; Murphy, Darra

    2015-04-01

    The elbow is a complex joint. Magnetic resonance imaging (MRI) is often the imaging modality of choice in the workup of elbow pain, especially in sports injuries and younger patients who often have either a history of a chronic repetitive strain such as the throwing athlete or a distinct traumatic injury. Traumatic injuries and alternative musculoskeletal pathologies can affect the ligaments, musculotendinous, cartilaginous, and osseous structures of the elbow as well as the 3 main nerves to the upper limb, and these structures are best assessed with MRI.Knowledge of the complex anatomy of the elbow joint as well as patterns of injury and disease is important for the radiologist to make an accurate diagnosis in the setting of elbow pain. This chapter will outline elbow anatomy, basic imaging parameters, compartmental pathology, and finally applications of some novel MRI techniques.

  12. Magnetic resonance imaging in the evaluation of acute stroke.

    PubMed

    Olivot, Jean Marc; Marks, Michael P

    2008-10-01

    The ability to use physiologic imaging with either magnetic resonance (MR) or computed tomography to help define irreversibly injured brain (the infarct core) and tissue at risk of infarct (reversible ischemic penumbra) holds great promise in the future treatment of stroke. The physiologic principles and concepts underlying the evaluation for mismatch between injured tissue and tissue at risk are similar for the 2 imaging techniques. Multimodal MR imaging (diffusion-weighted imaging/perfusion-weighted imaging/MR angiography) provides a validated penumbral selection criteria based on the results of 2 clinical trials (diffusion and perfusion imaging evaluation for understanding stroke evolution and echoplanar imaging thrombolysis evaluation). Computed tomographic perfusion parameters have also been calculated to optimize final infarct prediction. Both techniques await further study to prove their capability of selecting cases for short-term recanalization/reperfusion therapy.

  13. Image-Word Pairing-Congruity Effect on Affective Responses

    NASA Astrophysics Data System (ADS)

    Sanabria Z., Jorge C.; Cho, Youngil; Sambai, Ami; Yamanaka, Toshimasa

    The present study explores the effects of familiarity on affective responses (pleasure and arousal) to Japanese ad elements, based on the schema incongruity theory. Print ads showing natural scenes (landscapes) were used to create the stimuli (images and words). An empirical study was conducted to measure subjects' affective responses to image-word combinations that varied in terms of incongruity. The level of incongruity was based on familiarity levels, and was statistically determined by a variable called ‘pairing-congruity status’. The tested hypothesis proposed that even highly familiar image-word combinations, when combined incongruously, would elicit strong affective responses. Subjects assessed the stimuli using bipolar scales. The study was effective in tracing interactions between familiarity, pleasure and arousal, although the incongruous image-word combinations did not elicit the predicted strong effects on pleasure and arousal. The results suggest a need for further research incorporating kansei (i.e., creativity) into the process of stimuli selection.

  14. Bioresorbable vascular scaffold restenosis: intravascular imaging evaluation.

    PubMed

    Fabris, Enrico; Kilic, Ismail Dogu; Caiazzo, Gianluca; Serdoz, Roberta; Foin, Nicolas; Sinagra, Gianfranco; Di Mario, Carlo

    2015-11-21

    The mechanism of restenosis in bioresorbable vascular scaffold (BVS) may be different from that of metallic stents and it is still poorly investigated. Intravascular imaging techniques are useful tools for corroborating or excluding possible mechanisms of intra-scaffold restenosis. In these novel devices intravascular imaging should be systematically used for a better comprehension of the in-scaffold restenosis mechanism.

  15. Spectral response of the Viking lander camera: Preliminary evaluation

    NASA Technical Reports Server (NTRS)

    Kelly, W. L., IV; Huck, F. O.; Arvidson, R. E.

    1975-01-01

    One of the objectives of the Viking lander imaging investigation is to obtain color and near-infrared multispectral panoramas of the Martian surface using six spectral channels in the 0.4 to 1.1 microns wavelength range. This data can be compared with data obtained by imaging a reference test chart to construct approximate spectral reflectance curves that can then be matched to laboratory standards to aid in identifying surface materials. Some channels exhibit appreciable out-of-band spectral responses, making data reduction and interpretation difficult. A preliminary evaluation of predicted multispectral data for eight geological materials reveals that fairly good reflectance estimates can be made for those materials which have monotonically increasing or decreasing reflectances. Reflectance estimates for materials with more complex reflectances often do not reveal important spectral features and sometimes provide misleading results.

  16. Automation and Preclinical Evaluation of a Dedicated Emission Mammotomography System for Fully 3-D Molecular Breast Imaging

    DTIC Science & Technology

    2007-10-01

    OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for...an effort to evaluate the limits of object detectability for the dedicated CZT -based SPECT mammotomography imaging system under various imaging...dedicated CZT -based SPECT mammotomography imaging system under various imaging conditions. The molecular imaging system was also coupled onto the

  17. Progress in Evaluating Quantitative Optical Gas Imaging

    EPA Science Inventory

    Development of advanced fugitive emission detection and assessment technologies that facilitate cost effective leak and malfunction mitigation strategies is an ongoing goal shared by industry, regulators, and environmental groups. Optical gas imaging (OGI) represents an importan...

  18. Progress in Evaluating Quantitative Optical Gas Imaging

    EPA Science Inventory

    Development of advanced fugitive emission detection and assessment technologies that facilitate cost effective leak and malfunction mitigation strategies is an ongoing goal shared by industry, regulators, and environmental groups. Optical gas imaging (OGI) represents an importan...

  19. Therapy response evaluation with positron emission tomography-computed tomography.

    PubMed

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice.

  20. Performance evaluation methodology for historical document image binarization.

    PubMed

    Ntirogiannis, Konstantinos; Gatos, Basilis; Pratikakis, Ioannis

    2013-02-01

    Document image binarization is of great importance in the document image analysis and recognition pipeline since it affects further stages of the recognition process. The evaluation of a binarization method aids in studying its algorithmic behavior, as well as verifying its effectiveness, by providing qualitative and quantitative indication of its performance. This paper addresses a pixel-based binarization evaluation methodology for historical handwritten/machine-printed document images. In the proposed evaluation scheme, the recall and precision evaluation measures are properly modified using a weighting scheme that diminishes any potential evaluation bias. Additional performance metrics of the proposed evaluation scheme consist of the percentage rates of broken and missed text, false alarms, background noise, character enlargement, and merging. Several experiments conducted in comparison with other pixel-based evaluation measures demonstrate the validity of the proposed evaluation scheme.

  1. Performance evaluation of infrared imaging system in field test

    NASA Astrophysics Data System (ADS)

    Wang, Chensheng; Guo, Xiaodong; Ren, Tingting; Zhang, Zhi-jie

    2014-11-01

    Infrared imaging system has been applied widely in both military and civilian fields. Since the infrared imager has various types and different parameters, for system manufacturers and customers, there is great demand for evaluating the performance of IR imaging systems with a standard tool or platform. Since the first generation IR imager was developed, the standard method to assess the performance has been the MRTD or related improved methods which are not perfect adaptable for current linear scanning imager or 2D staring imager based on FPA detector. For this problem, this paper describes an evaluation method based on the triangular orientation discrimination metric which is considered as the effective and emerging method to evaluate the synthesis performance of EO system. To realize the evaluation in field test, an experiment instrument is developed. And considering the importance of operational environment, the field test is carried in practical atmospheric environment. The test imagers include panoramic imaging system and staring imaging systems with different optics and detectors parameters (both cooled and uncooled). After showing the instrument and experiment setup, the experiment results are shown. The target range performance is analyzed and discussed. In data analysis part, the article gives the range prediction values obtained from TOD method, MRTD method and practical experiment, and shows the analysis and results discussion. The experimental results prove the effectiveness of this evaluation tool, and it can be taken as a platform to give the uniform performance prediction reference.

  2. Evaluation of TV commercials using neurophysiological responses.

    PubMed

    Yang, Taeyang; Lee, Do-Young; Kwak, Youngshin; Choi, Jinsook; Kim, Chajoong; Kim, Sung-Phil

    2015-04-24

    In recent years, neuroscientific knowledge has been applied to marketing as a novel and efficient means to comprehend the cognitive and behavioral aspects of consumers. A number of studies have attempted to evaluate media contents, especially TV commercials using various neuroimaging techniques such as electroencephalography (EEG). Yet neurophysiological examination of detailed cognitive and affective responses in viewers is still required to provide practical information to marketers. Here, this study develops a method to analyze temporal patterns of EEG data and extract affective and cognitive indices such as happiness, surprise, and attention for TV commercial evaluation. Twenty participants participated in the study. We developed the neurophysiological indices for TV commercial evaluation using classification model. Specifically, these model-based indices were customized using individual EEG features. We used a video game for developing the index of attention and four video clips for developing indices of happiness and surprise. Statistical processes including one-way analyses of variance (ANOVA) and the cross validation scheme were used to select EEG features for each index. The EEG features were composed of the combinations of spectral power at selected channels from the cross validation for each individual. The Fisher's linear discriminant classifier (FLDA) was used to estimate each neurophysiological index during viewing four different TV commercials. Post hoc behavioral responses of preference, short-term memory, and recall were measured. Behavioral results showed significant differences for all preference, short-term memory rates, and recall rates between commercials, leading to a 'high-ranked' commercial group and a 'low-ranked' group (P < 0.05). Neural estimation of happiness results revealed a significant difference between the high-ranked and the low-ranked commercials in happiness index (P < 0.01). The order of rankings based on happiness and

  3. Monitoring human melanocytic cell responses to piperine using multispectral imaging

    NASA Astrophysics Data System (ADS)

    Samatham, Ravikant; Phillips, Kevin G.; Sonka, Julia; Yelma, Aznegashe; Reddy, Neha; Vanka, Meenakshi; Thuillier, Philippe; Soumyanath, Amala; Jacques, Steven

    2011-03-01

    Vitiligo is a depigmentary disease characterized by melanocyte loss attributed most commonly to autoimmune mechanisms. Currently vitiligo has a high incidence (1% worldwide) but a poor set of treatment options. Piperine, a compound found in black pepper, is a potential treatment for the depigmentary skin disease vitiligo, due to its ability to stimulate mouse epidermal melanocyte proliferation in vitro and in vivo. The present study investigates the use of multispectral imaging and an image processing technique based on local contrast to quantify the stimulatory effects of piperine on human melanocyte proliferation in reconstructed epidermis. We demonstrate the ability of the imaging method to quantify increased pigmentation in response to piperine treatment. The quantization of melanocyte stimulation by the proposed imaging technique illustrates the potential use of this technology to quickly assess therapeutic responses of vitiligo tissue culture models to treatment non-invasively.

  4. Satellite image collection modeling for large area hazard emergency response

    NASA Astrophysics Data System (ADS)

    Liu, Shufan; Hodgson, Michael E.

    2016-08-01

    Timely collection of critical hazard information is the key to intelligent and effective hazard emergency response decisions. Satellite remote sensing imagery provides an effective way to collect critical information. Natural hazards, however, often have large impact areas - larger than a single satellite scene. Additionally, the hazard impact area may be discontinuous, particularly in flooding or tornado hazard events. In this paper, a spatial optimization model is proposed to solve the large area satellite image acquisition planning problem in the context of hazard emergency response. In the model, a large hazard impact area is represented as multiple polygons and image collection priorities for different portion of impact area are addressed. The optimization problem is solved with an exact algorithm. Application results demonstrate that the proposed method can address the satellite image acquisition planning problem. A spatial decision support system supporting the optimization model was developed. Several examples of image acquisition problems are used to demonstrate the complexity of the problem and derive optimized solutions.

  5. Applying Quantitative CT Image Feature Analysis to Predict Response of Ovarian Cancer Patients to Chemotherapy.

    PubMed

    Danala, Gopichandh; Thai, Theresa; Gunderson, Camille C; Moxley, Katherine M; Moore, Kathleen; Mannel, Robert S; Liu, Hong; Zheng, Bin; Qiu, Yuchen

    2017-10-01

    The study aimed to investigate the role of applying quantitative image features computed from computed tomography (CT) images for early prediction of tumor response to chemotherapy in the clinical trials for treating ovarian cancer patients. A dataset involving 91 patients was retrospectively assembled. Each patient had two sets of pre- and post-therapy CT images. A computer-aided detection scheme was applied to segment metastatic tumors previously tracked by radiologists on CT images and computed image features. Two initial feature pools were built using image features computed from pre-therapy CT images only and image feature difference computed from both pre- and post-therapy images. A feature selection method was applied to select optimal features, and an equal-weighted fusion method was used to generate a new quantitative imaging marker from each pool to predict 6-month progression-free survival. The prediction accuracy between quantitative imaging markers and the Response Evaluation Criteria in Solid Tumors (RECIST) criteria was also compared. The highest areas under the receiver operating characteristic curve are 0.684 ± 0.056 and 0.771 ± 0.050 when using a single image feature computed from pre-therapy CT images and feature difference computed from pre- and post-therapy CT images, respectively. Using two corresponding fusion-based image markers, the areas under the receiver operating characteristic curve significantly increased to 0.810 ± 0.045 and 0.829 ± 0.043 (P < 0.05), respectively. Overall prediction accuracy levels are 71.4%, 80.2%, and 74.7% when using two imaging markers and RECIST, respectively. This study demonstrated the feasibility of predicting patients' response to chemotherapy using quantitative imaging markers computed from pre-therapy CT images. However, using image feature difference computed between pre- and post-therapy CT images yielded higher prediction accuracy. Copyright © 2017 The Association of University

  6. Evaluation of edge effect due to phase contrast imaging for mammography.

    PubMed

    Matsuo, Satoru; Katafuchi, Tetsuro; Tohyama, Keiko; Morishita, Junji; Yamada, Katsuhiko; Fujita, Hiroshi

    2005-08-01

    It is well-known that the edge effect produced by phase contrast imaging results in the edge enhancement of x-ray images and thereby sharpens those images. It has recently been reported that phase contrast imaging using practical x-ray tubes with small focal spots has improved image sharpness as observed in the phase contrast imaging with x-ray from synchrotron radiation or micro-focus x-ray tubes. In this study, we conducted the phase contrast imaging of a plastic fiber and plant seeds using a customized mammography equipment with a 0.1 mm focal spot, and the improvement of image sharpness was evaluated in terms of spatial frequency response of the images. We observed that the image contrast of the plastic fiber was increased by edge enhancement, and, as predicted elsewhere, spectral analysis revealed that as the spatial frequencies of the x-ray images increased, so did the sharpness gained through phase contrast imaging. Thus, phase contrast imaging using a practical molybdenum anode tube with a 0.1 mm-focal spot would benefit mammography, in which the morphological detectability of small species such as microcalcifications is of great concern. And detectability of tumor-surrounded glandular tissues in dense breast would be also improved by the phase contrast imaging.

  7. Quantitative image quality evaluation for cardiac CT reconstructions

    NASA Astrophysics Data System (ADS)

    Tseng, Hsin-Wu; Fan, Jiahua; Kupinski, Matthew A.; Balhorn, William; Okerlund, Darin R.

    2016-03-01

    Maintaining image quality in the presence of motion is always desirable and challenging in clinical Cardiac CT imaging. Different image-reconstruction algorithms are available on current commercial CT systems that attempt to achieve this goal. It is widely accepted that image-quality assessment should be task-based and involve specific tasks, observers, and associated figures of merits. In this work, we developed an observer model that performed the task of estimating the percentage of plaque in a vessel from CT images. We compared task performance of Cardiac CT image data reconstructed using a conventional FBP reconstruction algorithm and the SnapShot Freeze (SSF) algorithm, each at default and optimal reconstruction cardiac phases. The purpose of this work is to design an approach for quantitative image-quality evaluation of temporal resolution for Cardiac CT systems. To simulate heart motion, a moving coronary type phantom synchronized with an ECG signal was used. Three different percentage plaques embedded in a 3 mm vessel phantom were imaged multiple times under motion free, 60 bpm, and 80 bpm heart rates. Static (motion free) images of this phantom were taken as reference images for image template generation. Independent ROIs from the 60 bpm and 80 bpm images were generated by vessel tracking. The observer performed estimation tasks using these ROIs. Ensemble mean square error (EMSE) was used as the figure of merit. Results suggest that the quality of SSF images is superior to the quality of FBP images in higher heart-rate scans.

  8. Geometric and Radiometric Evaluation of Rasat Images

    NASA Astrophysics Data System (ADS)

    Cam, Ali; Topan, Hüseyin; Oruç, Murat; Özendi, Mustafa; Bayık, Çağlar

    2016-06-01

    RASAT, the second remote sensing satellite of Turkey, was designed and assembled, and also is being operated by TÜBİTAK Uzay (Space) Technologies Research Institute (Ankara). RASAT images in various levels are available free-of-charge via Gezgin portal for Turkish citizens. In this paper, the images in panchromatic (7.5 m GSD) and RGB (15 m GSD) bands in various levels were investigated with respect to its geometric and radiometric characteristics. The first geometric analysis is the estimation of the effective GSD as less than 1 pixel for radiometrically processed level (L1R) of both panchromatic and RGB images. Secondly, 2D georeferencing accuracy is estimated by various non-physical transformation models (similarity, 2D affine, polynomial, affine projection, projective, DLT and GCP based RFM) reaching sub-pixel accuracy using minimum 39 and maximum 52 GCPs. The radiometric characteristics are also investigated for 8 bits, estimating SNR between 21.8-42.2, and noise 0.0-3.5 for panchromatic and MS images for L1R when the sea is masked to obtain the results for land areas. The analysis show that RASAT images satisfies requirements for various applications. The research is carried out in Zonguldak test site which is mountainous and partly covered by dense forest and urban areas.

  9. Spectral and fluorescence imaging of immune system and tissue response to an immunogenic agent

    NASA Astrophysics Data System (ADS)

    Choe, Se-woon; Acharya, Abhinav; Keselowsky, Benjamin G.; Sorg, Brian S.

    2009-05-01

    Imaging of immune system and tissue response to immunogenic agents can be important to the development of new biomaterials. Additionally, quantitative functional imaging can be useful for testing and evaluation of methods to alter or control the immune system response to implanted materials. In this preliminary study, we employ spectral imaging and fluorescence imaging to measure immune system and tissue response to implanted immunogenic agents. Poly (D,L lactide-co-glycolide) (PLGA) with a 50:50 composition was used to create immunogenic microparticles (MPs). Lipopolysaccharide (LPS) encapsulated in the MPs was used to provoke a tissue immune response in mice and encapsulated fluorescein isothiocyanate (FITC) was used to fluorescently label the MPs for imaging. Control MPs did not contain LPS. The MPs were delivered at 50 particles/μL in a total volume of 20μL by subcutaneous injection in the skin of a nude mouse in a dorsal skin-fold window chamber preparation. Cultured immune cells from a mouse leukemic monocyte macrophage cell line were exogenously labeled with the fluorescent dye DiD in solution at a concentration of 8000cells/μL. Immediately after window chamber surgery and implantation of the MPs, 100μL of the fluorescent macrophage solution was administered via the tail vein. Fluorescence imaging was used to track MPs and macrophages while spectral imaging was used for imaging and measurement of hemoglobin saturation in the tissue microvasculature. Imaging was performed periodically over about three days. The spectral and fluorescence imaging combination enabled detailed observations of the macrophage response and functional effects on the tissue.

  10. Spectral analysis for evaluation of myocardial tracers for medical imaging

    SciTech Connect

    Huesman, Ronald H.; Reutter, Bryan W.; Marshall, Robert C.

    2000-10-11

    Kinetic analysis of dynamic tracer data is performed with the goal of evaluating myocardial radiotracers for cardiac nuclear medicine imaging. Data from experiments utilizing the isolated rabbit heart model are acquired by sampling the venous blood after introduction of a tracer of interest and a reference tracer. We have taken the approach that the kinetics are properly characterized by an impulse response function which describes the difference between the reference molecule (which does not leave the vasculature) and the molecule of interest which is transported across the capillary boundary and is made available to the cell. Using this formalism we can model the appearance of the tracer of interest in the venous output of the heart as a convolution of the appearance of the reference tracer with the impulse response. In this work we parameterize the impulse response function as the sum of a large number of exponential functions whose predetermined decay constants form a spectrum, and each is required only to have a nonnegative coefficient. This approach, called spectral analysis, has the advantage that it allows conventional compartmental analysis without prior knowledge of the number of compartments which the physiology may require or which the data will support.

  11. Series: Practical Evaluation of Clinical Image Quality (2): Image Quality Measurements for Digital Radiography Systems.

    PubMed

    Katayama, Reiji

    In recent years, the manuals and data analysis tools to evaluate the basic imaging properties of medical imaging systems, such as digital radiography system, CT, and MRI, are easily available. For the image quality evaluation of digital radiography systems, special measurement system, such as a microdensitometer, required for the analysis of analog radiography system, is not needed. This enabled anyone to perform the evaluation of digital radiography system.On the other hand, to make accurate measurements, obtaining appropriate image data is a must. To enable this, appropriate setting of the hardware and the software is also required. In addition, we are asked to acquire sufficient knowledge to make highly reproducible measurements.

  12. Millimeter-wave imaging sensor data evaluation

    NASA Technical Reports Server (NTRS)

    Wilson, William J.; Ibbott, Anthony C.

    1987-01-01

    A passive 3-mm radiometer system with a mechanically scanned antenna was built for use on a small aircraft or an Unmanned Aerial Vehicle to produce real near-real-time, moderate-resolution (0.5) images of the ground. One of the main advantages of this passive imaging sensor is that it is able to provide surveillance information through dust, smoke, fog and clouds when visual and IR systems are unusable. It can also be used for a variety of remote sensing applications, such as measurements of surface moisture, surface temperature, vegetation extent and snow cover. It is also possible to detect reflective objects under vegetation cover.

  13. Lower-Dark-Current, Higher-Blue-Response CMOS Imagers

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata; Cunningham, Thomas; Hancock, Bruce

    2008-01-01

    Several improved designs for complementary metal oxide/semiconductor (CMOS) integrated-circuit image detectors have been developed, primarily to reduce dark currents (leakage currents) and secondarily to increase responses to blue light and increase signal-handling capacities, relative to those of prior CMOS imagers. The main conclusion that can be drawn from a study of the causes of dark currents in prior CMOS imagers is that dark currents could be reduced by relocating p/n junctions away from Si/SiO2 interfaces. In addition to reflecting this conclusion, the improved designs include several other features to counteract dark-current mechanisms and enhance performance.

  14. PIRATE: pediatric imaging response assessment and targeting environment

    NASA Astrophysics Data System (ADS)

    Glenn, Russell; Zhang, Yong; Krasin, Matthew; Hua, Chiaho

    2010-02-01

    By combining the strengths of various imaging modalities, the multimodality imaging approach has potential to improve tumor staging, delineation of tumor boundaries, chemo-radiotherapy regime design, and treatment response assessment in cancer management. To address the urgent needs for efficient tools to analyze large-scale clinical trial data, we have developed an integrated multimodality, functional and anatomical imaging analysis software package for target definition and therapy response assessment in pediatric radiotherapy (RT) patients. Our software provides quantitative tools for automated image segmentation, region-of-interest (ROI) histogram analysis, spatial volume-of-interest (VOI) analysis, and voxel-wise correlation across modalities. To demonstrate the clinical applicability of this software, histogram analyses were performed on baseline and follow-up 18F-fluorodeoxyglucose (18F-FDG) PET images of nine patients with rhabdomyosarcoma enrolled in an institutional clinical trial at St. Jude Children's Research Hospital. In addition, we combined 18F-FDG PET, dynamic-contrast-enhanced (DCE) MR, and anatomical MR data to visualize the heterogeneity in tumor pathophysiology with the ultimate goal of adaptive targeting of regions with high tumor burden. Our software is able to simultaneously analyze multimodality images across multiple time points, which could greatly speed up the analysis of large-scale clinical trial data and validation of potential imaging biomarkers.

  15. Earth Observing-1 Advanced Land Imager: Radiometric Response Calibration

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Lencioni, D. E.; Evans, J. B.

    2000-01-01

    The Advanced Land Imager (ALI) is one of three instruments to be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). ALI contains a number of innovative features, including a wide field of view optical design, compact multispectral focal plane arrays, non-cryogenic HgCdTe detectors for the short wave infrared bands, and silicon carbide optics. This document outlines the techniques adopted during ground calibration of the radiometric response of the Advanced Land Imager. Results from system level measurements of the instrument response, signal-to-noise ratio, saturation radiance, and dynamic range for all detectors of every spectral band are also presented.

  16. Distribution of breath sound images in patients with pneumothoraces compared to healthy subjects. Diagnostic yield of vibration response imaging technology.

    PubMed

    Blanco, Montserrat; Mor, Ram; Fraticelli, Anne; Breen, David P; Dutau, Hervé

    2009-01-01

    Vibration response imaging (VRI) is a new technology that provides a radiation-free dynamic lung image from the vibrations produced by airflow. The vibration energy from the respiratory cycle can be quantified for any lung region. This is obtained by integrating the energy profiles from 42 acoustic sensors placed on the patient's back. The aim of this study was to evaluate whether a physician trained in interpreting acoustic images can accurately distinguish between normal and abnormal breath sound distribution in patients with pneumothoraces compared to healthy controls. In total, 14 patients with spontaneous or iatrogenic pneumothoraces and 15 healthy volunteers were enrolled in the study. VRI recordings and physical examination were obtained in all cases. Chest radiographs (CXRs) were reviewed in patients with pneumothoraces. Dynamic images recorded during one complete respiratory cycle were analyzed for each subject. The VRI images of patients with pneumothoraces demonstrated a reduction in the vibration response on the affected side which correlated with the CXR. Sensitivity was 100%, specificity was 87% and positive predictive value and negative predictive value were 86 and 100%, respectively. This study demonstrates that VRI can be safely used to assess patients with pneumothoraces. Moreover, the analysis of breath sound distribution images obtained noninvasively can distinguish between patients with a normal chest examination from those with pneumothoraces. 2008 S. Karger AG, Basel.

  17. A tool for designing digital test objects for module performance evaluation in medical digital imaging.

    PubMed

    Kocsis, O; Costaridou, L; Efstathopoulos, E P; Lymberopoulos, D; Panayiotakis, G

    1999-01-01

    Currently, medical digital imaging systems are characterized by the introduction of additional modules such as digital display, image compression and image processing, as well as film printing and digitization. These additional modules require performance evaluation to ensure high image quality. A tool for designing computer-generated test objects applicable to performance evaluation of these modules is presented. The test objects can be directly used as digital images in the case of film printing, display, compression and image processing, or indirectly as images on film in the case of digitization. The performance evaluation approach is quality control protocol based. Digital test object design is user-driven according to specifications related to the requirements of the modules being tested. The available quality control parameters include input/output response curve, high contrast resolution, low contrast discrimination, noise, geometric distortion and field uniformity. The tool has been designed and implemented according to an object oriented approach in Visual C++ 5.0, and its user interface is based on the Microsoft Foundation Class Library version 4.2, which provides interface items such as windows, dialog boxes, lists, buttons, etc. The compatibility with DICOM 3.0 part 10 image formats specifications allows the integration of the tool in the existing software framework for medical digital imaging systems. The capability of the tool is demonstrated by direct use of the test objects in case of image processing, and indirect use of the test objects in case of film digitization.

  18. [Possibility of using vibration response imaging in resuscitation and intensive care].

    PubMed

    Vinshtok, Iu L; Zelenin, G B; Gulitskiĭ, K E

    2010-01-01

    Lung monitoring and visualization in intensive care unit (ICU) patients is a difficult task. Chest X-ray and auscultation are the most commonly used methods today. The new technique vibration response imaging (VRI) based on the vibration that is generated by airflow in the lung and that is its surrogate manifestation allows visualization of lung function. This method provides clinicians with an easy-to-use, non-radiation, non-invasive acoustic-based imaging technique of visual and quantitative evaluation of the lung. VRI objective dynamic image is a clinical addition to the existing static visual modalities used in the ICU.

  19. Measurement of static convergence and accommodation responses to images of integral photography and binocular stereoscopy.

    PubMed

    Hiura, Hitoshi; Komine, Kazuteru; Arai, Jun; Mishina, Tomoyuki

    2017-02-20

    Static convergence and accommodation responses were measured by comparing integral photography images, binocular stereoscopic images, and real objects in a measurement range from 450 to 900 mm. The experimental results were evaluated with a multiple comparison test. It was found that six of the ten observers did not have an accommodation-convergence conflict in viewing integral photography in the range. Moreover, the required resolution was found to be 0.7 or more and less than 1.4 cycles per degree for inducing accommodation. In conclusion, integral photography can provide a natural 3D image that looks like a real object.

  20. Evaluation of a cloud-based local-read paradigm for imaging evaluations in oncology clinical trials for lung cancer

    PubMed Central

    Kobayashi, Naomi; Bonnard, Eric; Charbonnier, Colette; Yamamichi, Junta; Mizobe, Hideaki; Kimura, Shinya

    2015-01-01

    Background Although tumor response evaluated with radiological imaging is frequently used as a primary endpoint in clinical trials, it is difficult to obtain precise results because of inter- and intra-observer differences. Purpose To evaluate usefulness of a cloud-based local-read paradigm implementing software solutions that standardize imaging evaluations among international investigator sites for clinical trials of lung cancer. Material and Methods Two studies were performed: KUMO I and KUMO I Extension. KUMO I was a pilot study aiming at demonstrating the feasibility of cloud implementation and identifying issues regarding variability of evaluations among sites. Chest CT scans at three time-points from baseline to progression, from 10 patients with lung cancer who were treated with EGFR tyrosine kinase inhibitors, were evaluated independently by two oncologists (Japan) and one radiologist (France), through a cloud-based software solution. The KUMO I Extension was performed based on the results of KUMO I. Results KUMO I showed discordance rates of 40% for target lesion selection, 70% for overall response at the first time-point, and 60% for overall response at the second time-point. Since the main reason for the discordance was differences in the selection of target lesions, KUMO I Extension added a cloud-based quality control service to achieve a consensus on the selection of target lesions, resulting in an improved rate of agreement of response evaluations. Conclusion The study shows the feasibility of imaging evaluations at investigator sites, based on cloud services for clinical studies involving multiple international sites. This system offers a step forward in standardizing evaluations of images among widely dispersed sites. PMID:26668754

  1. Utility of Digital Stereo Images for Optic Disc Evaluation

    PubMed Central

    Ying, Gui-shuang; Pearson, Denise J.; Bansal, Mayank; Puri, Manika; Miller, Eydie; Alexander, Judith; Piltz-Seymour, Jody; Nyberg, William; Maguire, Maureen G.; Eledath, Jayan; Sawhney, Harpreet

    2010-01-01

    Purpose. To assess the suitability of digital stereo images for optic disc evaluations in glaucoma. Methods. Stereo color optic disc images in both digital and 35-mm slide film formats were acquired contemporaneously from 29 subjects with various cup-to-disc ratios (range, 0.26–0.76; median, 0.475). Using a grading scale designed to assess image quality, the ease of visualizing optic disc features important for glaucoma diagnosis, and the comparative diameters of the optic disc cup, experienced observers separately compared the primary digital stereo images to each subject's 35-mm slides, to scanned images of the same 35-mm slides, and to grayscale conversions of the digital images. Statistical analysis accounted for multiple gradings and comparisons and also assessed image formats under monoscopic viewing. Results. Overall, the quality of primary digital color images was judged superior to that of 35-mm slides (P < 0.001), including improved stereo (P < 0.001), but the primary digital color images were mostly equivalent to the scanned digitized images of the same slides. Color seemingly added little to grayscale optic disc images, except that peripapillary atrophy was best seen in color (P < 0.0001); both the nerve fiber layer (P < 0.0001) and the paths of blood vessels on the optic disc (P < 0.0001) were best seen in grayscale. The preference for digital over film images was maintained under monoscopic viewing conditions. Conclusions. Digital stereo optic disc images are useful for evaluating the optic disc in glaucoma and allow the application of advanced image processing applications. Grayscale images, by providing luminance distinct from color, may be informative for assessing certain features. PMID:20505199

  2. Image Registration for Quantitative Parametric Response Mapping of Cancer Treatment Response1

    PubMed Central

    Boes, Jennifer L; Hoff, Benjamin A; Hylton, Nola; Pickles, Martin D; Turnbull, Lindsay W; Schott, Anne F; Rehemtulla, Alnawaz; Chamberlain, Ryan; Lemasson, Benjamin; Chenevert, Thomas L; Galbán, Craig J; Meyer, Charles R; Ross, Brian D

    2014-01-01

    Imaging biomarkers capable of early quantification of tumor response to therapy would provide an opportunity to individualize patient care. Image registration of longitudinal scans provides a method of detecting treatment associated changes within heterogeneous tumors by monitoring alterations in the quantitative value of individual voxels over time, which is unattainable by traditional volumetric-based histogram methods. The concepts involved in the use of image registration for tracking and quantifying breast cancer treatment response using parametric response mapping (PRM), a voxel-based analysis of diffusion-weighted magnetic resonance imaging (DW-MRI) scans, are presented. Application of PRM to breast tumor response detection is described, wherein robust registration solutions for tracking small changes in water diffusivity in breast tumors during therapy are required. Methodologies that employ simulations are presented for measuring expected statistical accuracy of PRM for response assessment. Test-retest clinical scans are used to yield estimates of system noise to indicate significant changes in voxel-based changes in water diffusivity. Overall, registration-based PRM image analysis provides significant opportunities for voxel-based image analysis to provide the required accuracy for early assessment of response to treatment in breast cancer patients receiving neoadjuvant chemotherapy. PMID:24772213

  3. Evaluation of Multimodal Imaging Biomarkers of Prostate Cancer

    DTIC Science & Technology

    2014-09-01

    scan duration ~ 21 min). PET imaging was performed on a Concorde Microsystems microPET Focus 220. Approximately 120 uCi of tracer was administered...acquired anatomic MRI and PET data in orthotopic tumors within the Pten/p53 mouse model, to assess tumor volume, track growth and tumor angiogenesis...In fic speciregards to PET imaging, we have further characterized the use of FMISO, FDHT and TSPO imaging to evaluate tumor hypoxia, androgen

  4. Image Understanding Architecture Prototype Evaluation and Development

    DTIC Science & Technology

    1993-06-01

    database at the intermediate level is a more fundamental requirement than supporting particular algorithms. -i.. vii I TABLE OF CONTENTS I...57 I 3.3 Intermediate-level Symbolic Representation (ISR) Database ............ 64 3.3.1 Intermediate Symbolic Representation (ISR...ICAP, because the ICAP representation is in approximate registration with the original image events in the CAAPP. The ICAP serves as a database for the

  5. Reflected light imaging of ON and OFF responses in frog retina

    NASA Astrophysics Data System (ADS)

    Yao, Xin-Cheng; Liu, Lei; Li, Yang-Guo

    2009-02-01

    Using a near infrared (NIR) light flood-illumination imager equipped with a high-speed CCD camera, we demonstrated reflected light imaging of stimulus-evoked retinal ON and OFF responses in isolated, but intact, frog eye. Both fast and slow transient intrinsic optical signals (IOSs) were observed. Fast optical response occurred immediately after the stimulus onset, and correlated tightly with the ON and OFF edges of the visible light stimulus. High resolution images revealed both positive (increasing) and negative (decreasing) IOSs, and dynamic optical change at individual CCD pixels could often exceed 10% of the background light intensity. Our experiment on isolated eye suggests that further development of fast, high resolution fundus imager will allow robust detection of fast IOSs in vivo, and thus allow noninvasive, three-dimensional evaluation of retinal neural function.

  6. Using short-wave infrared imaging for fruit quality evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    Quality evaluation of agricultural and food products is important for processing, inventory control, and marketing. Fruit size and surface quality are two important quality factors for high-quality fruit such as Medjool dates. Fruit size is usually measured by length that can be done easily by simple image processing techniques. Surface quality evaluation on the other hand requires more complicated design, both in image acquisition and image processing. Skin delamination is considered a major factor that affects fruit quality and its value. This paper presents an efficient histogram analysis and image processing technique that is designed specifically for real-time surface quality evaluation of Medjool dates. This approach, based on short-wave infrared imaging, provides excellent image contrast between the fruit surface and delaminated skin, which allows significant simplification of image processing algorithm and reduction of computational power requirements. The proposed quality grading method requires very simple training procedure to obtain a gray scale image histogram for each quality level. Using histogram comparison, each date is assigned to one of the four quality levels and an optimal threshold is calculated for segmenting skin delamination areas from the fruit surface. The percentage of the fruit surface that has skin delamination can then be calculated for quality evaluation. This method has been implemented and used for commercial production and proven to be efficient and accurate.

  7. Imaging Evaluation of Dogs and Cats with Dysphagia

    PubMed Central

    Pollard, Rachel E.

    2012-01-01

    The current literature is reviewed in this paper regarding the application of diagnostic imaging in the evaluation of swallowing disorders of the dog. The applications of radiography, contrast radiography, and contrast videofluoroscopy are discussed with pertinent case examples provided for emphasis. The indications for image-guided interventions are also described. PMID:23762579

  8. Imaging evaluation of dogs and cats with Dysphagia.

    PubMed

    Pollard, Rachel E

    2012-01-01

    The current literature is reviewed in this paper regarding the application of diagnostic imaging in the evaluation of swallowing disorders of the dog. The applications of radiography, contrast radiography, and contrast videofluoroscopy are discussed with pertinent case examples provided for emphasis. The indications for image-guided interventions are also described.

  9. Super-resolution image reconstruction for ultrasonic nondestructive evaluation.

    PubMed

    Li, Shanglei; Chu, Tsuchin Philip

    2013-12-01

    Ultrasonic testing is one of the most successful nondestructive evaluation (NDE) techniques for the inspection of carbon-fiber-reinforced polymer (CFRP) materials. This paper discusses the application of the iterative backprojection (IBP) super-resolution image reconstruction technique to carbon epoxy laminates with simulated defects to obtain high-resolution images for NDE. Super-resolution image reconstruction is an approach used to overcome the inherent resolution limitations of an existing ultrasonic system. It can greatly improve the image quality and allow more detailed inspection of the region of interest (ROI) with high resolution, improving defect evaluation and accuracy. First, three artificially simulated delamination defects in a CFRP panel were considered to evaluate and validate the application of the IBP method. The results of the validation indicate that both the contrast-tonoise ratio (CNR) and the peak signal-to-noise ratio (PSNR) value of the super-resolution result are better than the bicubic interpolation method. Then, the IBP method was applied to the low-resolution ultrasonic C-scan image sequence with subpixel displacement of two types of defects (delamination and porosity) which were obtained by the micro-scanning imaging technique. The result demonstrated that super-resolution images achieved better visual quality with an improved image resolution compared with raw C-scan images.

  10. Image Information Mining System Evaluation Using Information-Theoretic Measures

    NASA Astrophysics Data System (ADS)

    Daschiel, Herbert; Datcu, Mihai

    2005-12-01

    During the last decade, the exponential increase of multimedia and remote sensing image archives, the fast expansion of the world wide web, and the high diversity of users have yielded concepts and systems for successful content-based image retrieval and image information mining. Image data information systems require both database and visual capabilities, but there is a gap between these systems. Database systems usually do not deal with multidimensional pictorial structures and vision systems do not provide database query functions. In terms of these points, the evaluation of content-based image retrieval systems became a focus of research interest. One can find several system evaluation approaches in literature, however, only few of them go beyond precision-recall graphs and do not allow a detailed evaluation of an interactive image retrieval system. Apart from the existing evaluation methodologies, we aim at the overall validation of our knowledge-driven content-based image information mining system. In this paper, an evaluation approach is demonstrated that is based on information-theoretic quantities to determine the information flow between system levels of different semantic abstraction and to analyze human-computer interactions.

  11. An efficient perceived contrast evaluation model for natural images

    NASA Astrophysics Data System (ADS)

    Chen, Qiao Song; Kim, Choon-Woo

    2010-01-01

    Perceived image contrast is one of the major factors affecting the image quality on displays. Various methods have been proposed to measure the image contrast. However, image contrasts in most of previous works are focused on B/W and defined on simple patterns such as sinusoidal grating. This paper introduces a perceived contrast evaluation model for natural color images. In pursuit of high accuracy, both global and local contrasts are taken into account. Global contrast indicates difference in the perceived luminance and chroma. Local contrast describes the distinguishable degree in image details. In the proposed method, global contrast is calculated based on the dynamic ranges in lightness and chroma. Local contrast is obtained by gradient computations. Both of the global and local contrasts are merged to achieve the perceived contrast. Two types of performance evaluations are performed. They are cross content and within content evaluations. Results of experiments show that global contrast is more effective in the cross content evaluation where the contrast differences between different natural color images are examined. For both of the cross and within content evaluations, the proposed measure yields high value of correlation coefficient with the subjective scores from human visual tests.

  12. Longitudinal, multimodal functional imaging of microvascular response to photothermal therapy

    PubMed Central

    Bui, Albert K.; Teves, Kathleen M.; Indrawan, Elmer; Jia, Wangcun; Choi, Bernard

    2012-01-01

    Although studies have shown that photothermal therapy can coagulate selectively abnormal vasculature, the ability of this method to achieve consistent, complete removal of the vasculature is questionable. We present the use of multimodal, wide-field functional imaging to study, in greater detail, the biological response to selective laser injury. Specifically, a single-platform instrument capable of coregistered fluorescence imaging and laser speckle imaging was utilized to monitor vascular endothelial growth factor gene expression and blood flow, respectively, in a transgenic rodent model. Collectively, the longitudinal, in vivo data collected with our instrument suggest that the biological response to selective laser injury involves early-stage redistribution of blood flow, followed by increased vascular endothelial growth factor promoter activity to stimulate pro-angiogenic events. PMID:20890338

  13. Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

    PubMed Central

    Yang, Ke; Zhang, Xiao-Ming; Yang, Lin; Xu, Hao; Peng, Juan

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization (TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusion-weighted magnetic resonance imaging (MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusion-weighted imaging, blood oxygen level-dependent MRI, positron emission tomography (PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed. PMID:27239110

  14. Model of Host-Pathogen Interaction Dynamics Links In Vivo Optical Imaging and Immune Responses

    PubMed Central

    Ale, Angelique; Crepin, Valerie F.; Collins, James W.; Constantinou, Nicholas; Habibzay, Maryam; Babtie, Ann C.

    2016-01-01

    ABSTRACT Tracking disease progression in vivo is essential for the development of treatments against bacterial infection. Optical imaging has become a central tool for in vivo tracking of bacterial population development and therapeutic response. For a precise understanding of in vivo imaging results in terms of disease mechanisms derived from detailed postmortem observations, however, a link between the two is needed. Here, we develop a model that provides that link for the investigation of Citrobacter rodentium infection, a mouse model for enteropathogenic Escherichia coli (EPEC). We connect in vivo disease progression of C57BL/6 mice infected with bioluminescent bacteria, imaged using optical tomography and X-ray computed tomography, to postmortem measurements of colonic immune cell infiltration. We use the model to explore changes to both the host immune response and the bacteria and to evaluate the response to antibiotic treatment. The developed model serves as a novel tool for the identification and development of new therapeutic interventions. PMID:27821583

  15. Quantification of Kr-81m ventilation image response to methacholine

    SciTech Connect

    Byrom, E.; Chausow, A.; Ryo, U.Y.; Kim, I.; Pinsky, S.

    1984-01-01

    Ventilation imaging with Kr-81m was used to study the response of regional ventilation to bronchial provocation with methacholine. Subjects were imaged seated, for 2 min, following inhalation of methacoline. Then maximal flow at 30% of vital capacity (MEF-30p) and forced expiratory volume in 1 sec (FEV 1) were measured. The procedure was repeated for 11 doses. Total ventilation is constant by design. Regional changes between each image (T) and a baseline image (B) were measured from a difference image (D), where D/sub i/=(S.T/sub i/-B/sub i/)/sqrt (S/sup 2/.T/sub i/+B/sub i/), and S normalizes T to the same total counts as B. The D/sub i/ values have a gaussian distribution with standard deviation (SD)=1, if B, T are independent images of the same object. The area of mismatch (AOM) between the D/sub i/ histogram and the ideal qaussian curve, and its SD, were calculated. Thresholds of significant response were established at 2.0 for SD, 1100 for AOM to allow for the effects of repositioning. Three subjects undertook the provocation study. In subject number 1(2,3), MEF-30p fell below 70% of baseline after dose number 8(7,6); a region of reduced ventilation was seen in D, at the left lung base, after dose 6(4,5); SD rose above the threshold after dose 7(6,7); AOM after dose 8(6,7). In subjects 2 and 3, FEV 1 fell below 80% of baseline after dose 10. In conclusion SD, AOM are as sensitive as MEF-30p in detecting response to methacholine: and more sensitive than FEV 1. The D images may be more sensitive, if repositioning artifacts can be avoided.

  16. [Imaging in the evaluation of headaches].

    PubMed

    Chacowry Pala, K; Platon, A; Delémont, C

    2013-09-25

    Headache is a common complaint in primary care medicine. Most of the time, they are primary and benign headaches, with no need for further investigations; nevertheless, in the presence of red flags, a brain imaging is warranted. The diagnostic approach depends upon the most likely suspected cause and the degree of emergency. In those situations, a head CT scan without and with contrast is the exam of choice in most patients, because it is helpful for identifying intracranial lesions or bleeding. The MRI, more sensible, is preferred in the ambulatory setting for investigation and follow-up of intracranial tumoral or infectious diseases.

  17. Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

    PubMed

    Ohara, Yoshikazu; Horinouchi, Satoshi; Hashimoto, Makoto; Shintaku, Yohei; Yamanaka, Kazushi

    2011-08-01

    To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load. Therefore, only cracks can be extracted by subtracting responses at different loads. In this study, we performed fundamental experiments on a closed fatigue crack formed in an aluminum alloy compact tension (CT) specimen using the proposed method. We examined the static load dependence of SPACE images and the dynamic load dependence of linear phased array (PA) images by simulating the external loads with a servohydraulic fatigue testing machine. By subtracting the images at different external loads, we show that this method is useful in extracting only the intensity change of responses related to closed cracks, while canceling the responses of objects other than cracks.

  18. Functional evaluation of telemedicine with super high definition images and B-ISDN.

    PubMed

    Takeda, H; Matsumura, Y; Okada, T; Kuwata, S; Komori, M; Takahashi, T; Minatom, K; Hashimoto, T; Wada, M; Fujio, Y

    1998-01-01

    In order to determine whether a super high definition (SHD) image running at a series of 2048 resolution x 2048 line x 60 frame/sec was capable of telemedicine, we established a filing system for medical images and two experiments for transmission of high quality images were performed. All images of various types, produced from one case of ischemic heart disease were digitized and registered into the filing system. Images consisted of plain chest x-ray, electrocardiogram, ultrasound cardiogram, cardiac scintigram, coronary angiogram, left ventriculogram and so on. All images were animated and totaled a number of 243. We prepared a graphic user interface (GUI) for image retrieval based on the medical events and modalities. Twenty one cardiac specialists evaluated quality of the SHD images to be somewhat poor compared to the original pictures but sufficient for making diagnoses, and effective as a tool for teaching and case study purposes. The system capability of simultaneously displaying several animated images was especially deemed effective in grasping comprehension of diagnosis. Efficient input methods and creating capacity of filing all produced images are future issue. Using B-ISDN network, the SHD file was prefetched to the servers at Kyoto University Hospital and BBCC (Bradband ISDN Business chance & Culture Creation) laboratory as an telemedicine experiment. Simultaneous video conference system, the control of image retrieval and pointing function made the teleconference successful in terms of high quality of medical images, quick response time and interactive data exchange.

  19. Objective measurements to evaluate glottal space segmentation from laryngeal images.

    PubMed

    Gutiérrez-Arriola, J M; Osma-Ruiz, V; Sáenz-Lechón, N; Godino-Llorente, J I; Fraile, R; Arias-Londoño, J D

    2012-01-01

    Objective evaluation of the results of medical image segmentation is a known problem. Applied to the task of automatically detecting the glottal area from laryngeal images, this paper proposes a new objective measurement to evaluate the quality of a segmentation algorithm by comparing with the results given by a human expert. The new figure of merit is called Area Index, and its effectiveness is compared with one of the most used figures of merit found in the literature: the Pratt Index. Results over 110 laryngeal images presented high correlations between both indexes, demonstrating that the proposed measure is comparable to the Pratt Index and it is a good indicator of the segmentation quality.

  20. Image processing as a tool in flight testing evaluation

    NASA Astrophysics Data System (ADS)

    Kaelldahl, Anders

    1991-05-01

    An advanced system for digitizing and automatically analyzing film and video images and its adaptation for specific purposes are described. A video camera of charge coupled devices type was installed in a Viggen test aircraft and flight tests of sensitivity for different wavelengths and measurable resolution were carried out. A video tape containing interesting runs was input into an image processing system in order to show that the video based system meets the specification for Head Up Display (HUD) evaluation. A market investigation was undertaken for an image processing system for HUD evaluation, with particular requirements on a high performance time base corrector in the video input unit, video disks, image processor, and display unit. A digital video disk system and a tracking algorithm based on correlation methods were chosen; the image processing system was completed with a film scanner for converting cinema films into a digital format. In addition to the HUD analysis technique, a photogrammetric system was used for testing microwave landing, radar altimeter, or third category landing system. It is concluded that this image processing system provides evaluation time reduction, higher possibility for correct evaluation and higher accuracy since more points from each image are used.

  1. DATA SYNTHESIS AND METHOD EVALUATION FOR BRAIN IMAGING GENETICS.

    PubMed

    Sheng, Jinhua; Kim, Sungeun; Yan, Jingwen; Moore, Jason; Saykin, Andrew; Shen, Li

    2014-05-01

    Brain imaging genetics is an emergent research field where the association between genetic variations such as single nucleotide polymorphisms (SNPs) and neuroimaging quantitative traits (QTs) is evaluated. Sparse canonical correlation analysis (SCCA) is a bi-multivariate analysis method that has the potential to reveal complex multi-SNP-multi-QT associations. We present initial efforts on evaluating a few SCCA methods for brain imaging genetics. This includes a data synthesis method to create realistic imaging genetics data with known SNP-QT associations, application of three SCCA algorithms to the synthetic data, and comparative study of their performances. Our empirical results suggest, approximating covariance structure using an identity or diagonal matrix, an approach used in these SCCA algorithms, could limit the SCCA capability in identifying the underlying imaging genetics associations. An interesting future direction is to develop enhanced SCCA methods that effectively take into account the covariance structures in the imaging genetics data.

  2. Free segmentation in rendered 3D images through synthetic impulse response in integral imaging

    NASA Astrophysics Data System (ADS)

    Martínez-Corral, M.; Llavador, A.; Sánchez-Ortiga, E.; Saavedra, G.; Javidi, B.

    2016-06-01

    Integral Imaging is a technique that has the capability of providing not only the spatial, but also the angular information of three-dimensional (3D) scenes. Some important applications are the 3D display and digital post-processing as for example, depth-reconstruction from integral images. In this contribution we propose a new reconstruction method that takes into account the integral image and a simplified version of the impulse response function (IRF) of the integral imaging (InI) system to perform a two-dimensional (2D) deconvolution. The IRF of an InI system has a periodic structure that depends directly on the axial position of the object. Considering different periods of the IRFs we recover by deconvolution the depth information of the 3D scene. An advantage of our method is that it is possible to obtain nonconventional reconstructions by considering alternative synthetic impulse responses. Our experiments show the feasibility of the proposed method.

  3. Men Respond Too: The Effects of a Social-Evaluative Body Image Threat on Shame and Cortisol in University Men.

    PubMed

    Lamarche, Larkin; Ozimok, Brianne; Gammage, Kimberley L; Muir, Cameron

    2017-09-01

    Framed within social self-preservation theory, the present study investigated men's psychobiological responses to social-evaluative body image threats. University men ( n = 66) were randomly assigned to either a high or low social-evaluative body image threat condition. Participants provided saliva samples (to assess cortisol) and completed measures of state body shame prior to and following their condition, during which anthropometric and strength measures were assessed. Baseline corrected values indicated men in the high social-evaluative body image threat condition had higher body shame and cortisol than men in the low social-evaluative body image threat condition. These findings suggest that social evaluation in the context of situations that threaten body image leads to potentially negative psychobiological responses in college men.

  4. Molecular Magnetic Resonance Imaging of Tumor Response to Therapy

    PubMed Central

    Shuhendler, Adam J.; Ye, Deju; Brewer, Kimberly D.; Bazalova-Carter, Magdalena; Lee, Kyung-Hyun; Kempen, Paul; Dane Wittrup, K.; Graves, Edward E.; Rutt, Brian; Rao, Jianghong

    2015-01-01

    Personalized cancer medicine requires measurement of therapeutic efficacy as early as possible, which is optimally achieved by three-dimensional imaging given the heterogeneity of cancer. Magnetic resonance imaging (MRI) can obtain images of both anatomy and cellular responses, if acquired with a molecular imaging contrast agent. The poor sensitivity of MRI has limited the development of activatable molecular MR contrast agents. To overcome this limitation of molecular MRI, a novel implementation of our caspase-3-sensitive nanoaggregation MRI (C-SNAM) contrast agent is reported. C-SNAM is triggered to self-assemble into nanoparticles in apoptotic tumor cells, and effectively amplifies molecular level changes through nanoaggregation, enhancing tissue retention and spin-lattice relaxivity. At one-tenth the current clinical dose of contrast agent, and following a single imaging session, C-SNAM MRI accurately measured the response of tumors to either metronomic chemotherapy or radiation therapy, where the degree of signal enhancement is prognostic of long-term therapeutic efficacy. Importantly, C-SNAM is inert to immune activation, permitting radiation therapy monitoring. PMID:26440059

  5. Evaluating Potential Response-Modifying Factors for ...

    EPA Pesticide Factsheets

    Epidemiologic and experimental studies have demonstrated a variety of health effects in response to ozone (O3) exposure. Studies have demonstrated that some populations may be at increased risk of O3-related health effects. Objectives: To identify populations and lifestages potentially at increased risk of O3-related health effects by applying a novel strength of evidence approach for identifying and classifying factors associated with increased risk. Methods: Epidemiologic, experimental, and exposure science studies of populations potentially at increased risk of O3-related health effects were identified and evidence was integrated across disciplines to evaluate consistency, coherence, and biological plausibility of effects. The factors identified were then classified using a strength of evidence approach to conclude whether a population or lifestage is at increased risk of O3-related health effects. Discussion: We found “adequate” evidence that populations with certain genotypes, different lifestages, populations with preexisting asthma, populations with reduced intake of certain nutrients, and outdoor workers are at increased risk of O3 related health effects. Additionally, we identified other factors (i.e., sex, SES, and obesity) for which there was “suggestive” evidence of increased risk of O3-related health effects. Conclusions: We identified a diverse group of factors that potentially result in an increased risk of O3-related health effects.

  6. Image evaluation using a color visual difference predictor (CVDP)

    NASA Astrophysics Data System (ADS)

    Lian, Ming-Shih

    2001-06-01

    In order to automate the image evaluation task, an engineering model for predicting the visual differences of color images is developed. The present CVDP consists of a color appearance model, a set of contrast sensitivity functions, the modified cortex transform, and a multichannel interaction model for masking effects. Based ona pixel-by- pixel difference metric similar to the CIELAB color difference, the predictions of the simplified CVDP are found to correlate fairly with the psychophysical test results over 51 pairs of natural images with some detection failures. These failures can be eliminated by including additional image quality metrics: the clarity in the shadow and highlight areas and the graininess in the mid-tone areas. The modified model is found to be able to identify 55 percent of those visually indistinguishable image pairs. The preliminary results using the complete CVDP for selected image pairs indicate that the effects of masking introduce only little changes to the results of the simplified CVDP.

  7. Tumour response evaluation with fluorodeoxyglucose positron emission tomography: research technique or clinical tool?

    PubMed

    Anderson, H; Singh, N; Miles, K

    2010-10-04

    The evaluation of treatment response is an established role for imaging in oncologic research and clinical practice. In early phase trials, imaging response criteria are used to determine the presence and magnitude of the drug effect on tumour to aid decisions concerning progress to late phase trials, and to inform dose selection and scheduling. In late phase trials and clinical practice, the imaging response is used as a surrogate for clinical outcome. Due to the limitations of current anatomic response criteria, there is growing interest in the use of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess treatment response. The technique is beginning to be adopted within mainstream approaches for evaluation of response in solid tumours and lymphoma. Difficulties with standardisation across PET centres and tumour types combined with uncertainty concerning the timing of assessment relative to treatment, have limited the use of quantitative measurements of FDG uptake to research applications. However, with a growing body of evidence that qualitative criteria such as the development of new PET lesions or complete metabolic response following treatment can provide surrogates marker for clinical outcome, [(18)F]FDG-PET is becoming established as a clinical technique for assessing tumour response, especially for FDG-avid lymphoma subtypes. Multimodality imaging using perfusion computed tomography/PET is an exciting novel technique with the potential to define treatment response in a new way.

  8. Evaluation of outliers in acquired brain MR images

    NASA Astrophysics Data System (ADS)

    Moldovanu, S.; (Vişan Pungǎ, M.; Moraru, L.

    2015-01-01

    Pre-processing is an important stage in the analysis of magnetic resonance images (MRI), because the effect of specific image artefacts, such as intensity inhomogeneity, noise and low contrast can adversely affect the quantitative image analysis. The image histogram is a useful tool in the analysis of MR images given that it allows a close relationship with important image features such as contrast and noise. The noise and variable contrast are elements that locally modify the quality of images. The key issue of this study derives from the fact that the spatial histogram can contain outliers indicating corrupted image information through the disorder of the bins. These aberrant errors should be excluded from the studied data sets. Here, the outliers are evaluated by using rigorous methods based on the probability theory and Chauvenet (CC), Grubbs (GC) and Peirce's (PC) criteria. In order to check the quality of the MR images, the Minkowsky (MD), Euclidean (ED) and cosine (CD) distance functions were used. They act as similarity scores between the histogram of the acquired MRI and the processed image. This analysis is necessary because, sometimes, the distance function exceeds the co-domain because of the outliers. In this paper, 32 MRIs are tested and the outliers are removed so that the distance functions generate uncorrupted and real values.

  9. Evaluation of copyright protection schemes for hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Minguillon, Julia; Herrera-Joancomarti, Jordi; Megias, David; Serra-Sagrista, Joan

    2004-02-01

    In this paper we evaluate the performance of several image watermarking schemes applied to hyperspectral imaging. An image watermarking scheme based on JPEG2000 which can be also used to store and manipulate hyperspectral images is also described. Different watermarking schemes are tested in order to determine the suitability of each one for a specific hyperspectral image environment. The impact of classical GIS operations (namely zooming, cropping and compression) on the performance of each watermarking scheme is measured in terms of capacity and robustness. In order to do so, we study several possibilities for watermarking hyperspectral images, as all hyperspectral image bands should be taken into account. We also study the impact of watermarking in image quality, measured as usual by PSNR, but also by the degradation of classification performance. Compression, classification and watermarking are closely related to each other as decisions taken in one subject have a large impact on the others. Our results show that the newcomer JPEG2000 standard is a useful tool for both hyperspectral imaging and copyright protection purposes. The proposed watermarking scheme, which takes advantage of JPEG2000 standard capabilities, can be considered to be robust under the constraints defined by the integration of hyperspectral imaging with geographical information systems. JPEG2000 extensions defined by the standard related to this work are also considered.

  10. A quantitative approach to evaluate image quality of whole slide imaging scanners

    PubMed Central

    Shrestha, Prarthana; Kneepkens, R.; Vrijnsen, J.; Vossen, D.; Abels, E.; Hulsken, B.

    2016-01-01

    Context: The quality of images produced by whole slide imaging (WSI) scanners has a direct influence on the readers’ performance and reliability of the clinical diagnosis. Therefore, WSI scanners should produce not only high quality but also consistent quality images. Aim: We aim to evaluate reproducibility of WSI scanners based on the quality of images produced over time and among multiple scanners. The evaluation is independent of content or context of test specimen. Methods: The ultimate judge of image quality is a pathologist, however, subjective evaluations are heavily influenced by the complexity of a case and subtle variations introduced by a scanner can be easily overlooked. Therefore, we employed a quantitative image quality assessment method based on clinically relevant parameters, such as sharpness and brightness, acquired in a survey of pathologists. The acceptable level of quality per parameter was determined in a subjective study. The evaluation of scanner reproducibility was conducted with Philips Ultra-Fast Scanners. A set of 36 HercepTest™ slides were used in three sub-studies addressing variations due to systems and time, producing 8640 test images for evaluation. Results: The results showed that the majority of images in all the sub-studies are within the acceptable quality level; however, some scanners produce higher quality images more often than others. The results are independent of case types, and they match our perception of quality. Conclusion: The quantitative image quality assessment method was successfully applied in the HercepTest™ slides to evaluate WSI scanner reproducibility. The proposed method is generic and applicable to any other types of slide stains and scanners. PMID:28197359

  11. Neural attention and evaluative responses to gay and lesbian couples.

    PubMed

    Dickter, Cheryl L; Forestell, Catherine A; Mulder, Blakely E

    2015-01-01

    The goal of the current study was to examine whether differential neural attentional capture and evaluative responses for out-group homosexual relative to in-group heterosexual targets occur during social categorization. To this end, 36 heterosexual participants were presented with pictures of heterosexual and homosexual couples in a picture-viewing task that was designed to assess implicit levels of discomfort toward homosexuality and explicit evaluations of pleasantness toward the images. Neural activity in the form of electroencephalogram was recorded during the presentation of the pictures, and event-related potentials resulting from these stimuli were examined. Participants also completed questionnaires that assessed the degree to which they socialized with gays and lesbians. Results demonstrated that relative to straight couples, larger P2 amplitude was observed in response to gay but not to lesbian couples. However, both gay and lesbian couples yielded a larger late positive potential than straight couples. Moreover, the degree to which participants differentially directed early neural attention to out-group lesbian versus in-group straight couples was related to their familiarity with homosexual individuals. This work, which provides an initial understanding of the neural underpinnings of attention toward homosexual couples, suggests that differences in the processing of sexual orientation can occur as early as 200 ms and may be moderated by familiarity.

  12. Molecular Imaging and Precision Medicine: PET/Computed Tomography and Therapy Response Assessment in Oncology.

    PubMed

    Sheikhbahaei, Sara; Mena, Esther; Pattanayak, Puskar; Taghipour, Mehdi; Solnes, Lilja B; Subramaniam, Rathan M

    2017-01-01

    A variety of methods have been developed to assess tumor response to therapy. Standardized qualitative criteria based on 18F-fluoro-deoxyglucose PET/computed tomography have been proposed to evaluate the treatment effectiveness in specific cancers and these allow more accurate therapy response assessment and survival prognostication. Multiple studies have addressed the utility of the volumetric PET biomarkers as prognostic indicators but there is no consensus about the preferred segmentation methodology for these metrics. Heterogeneous intratumoral uptake was proposed as a novel PET metric for therapy response assessment. PET imaging techniques will be used to study the biological behavior of cancers during therapy.

  13. Evaluation of thermal imaging cameras used in fire fighting applications

    NASA Astrophysics Data System (ADS)

    Amon, Francine; Bryner, Nelson; Hamins, Anthony

    2004-08-01

    Thermal imaging cameras are rapidly becoming integral equipment for first responders for use in structure fires. Currently there are no standardized test methods or performance metrics available to the users or manufacturers of these instruments. The Building and Fire Research Laboratory (BFRL) at the National Institute of Standards and Technology (NIST) is developing a testing facility and methods to evaluate the performance of thermal imagers used by fire fighters to search for victims and hot spots in burning structures. The facility will test the performance of currently available imagers and advanced fire detection systems, as well as serve as a test bed for new technology. An evaluation of the performance of different thermal imaging detector technologies under field conditions is also underway. Results of this project will provide a quantifiable physical and scientific basis upon which industry standards for imaging performance, testing protocols and reporting practices related to the performance of thermal imaging cameras can be developed. The background and approach that shape the evaluation procedure for the thermal imagers are the primary focus of this paper.

  14. Magnetic resonance imaging of the chest in the evaluation of cancer patients: state of the art.

    PubMed

    Guimaraes, Marcos Duarte; Hochhegger, Bruno; Santos, Marcel Koenigkam; Santana, Pablo Rydz Pinheiro; Sousa, Arthur Soares; Souza, Luciana Soares; Marchiori, Edson

    2015-01-01

    Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias.

  15. Magnetic resonance imaging of the chest in the evaluation of cancer patients: state of the art

    PubMed Central

    Guimaraes, Marcos Duarte; Hochhegger, Bruno; Santos, Marcel Koenigkam; Santana, Pablo Rydz Pinheiro; Sousa, Arthur Soares; Souza, Luciana Soares; Marchiori, Edson

    2015-01-01

    Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias. PMID:25798006

  16. Metal artifact reduction and image quality evaluation of lumbar spine CT images using metal sinogram segmentation.

    PubMed

    Kaewlek, Titipong; Koolpiruck, Diew; Thongvigitmanee, Saowapak; Mongkolsuk, Manus; Thammakittiphan, Sastrawut; Tritrakarn, Siri-on; Chiewvit, Pipat

    2015-01-01

    Metal artifacts often appear in the images of computed tomography (CT) imaging. In the case of lumbar spine CT images, artifacts disturb the images of critical organs. These artifacts can affect the diagnosis, treatment, and follow up care of the patient. One approach to metal artifact reduction is the sinogram completion method. A mixed-variable thresholding (MixVT) technique to identify the suitable metal sinogram is proposed. This technique consists of four steps: 1) identify the metal objects in the image by using k-mean clustering with the soft cluster assignment, 2) transform the image by separating it into two sinograms, one of which is the sinogram of the metal object, with the surrounding tissue shown in the second sinogram. The boundary of the metal sinogram is then found by the MixVT technique, 3) estimate the new value of the missing data in the metal sinogram by linear interpolation from the surrounding tissue sinogram, 4) reconstruct a modified sinogram by using filtered back-projection and complete the image by adding back the image of the metal object into the reconstructed image to form the complete image. The quantitative and clinical image quality evaluation of our proposed technique demonstrated a significant improvement in image clarity and detail, which enhances the effectiveness of diagnosis and treatment.

  17. [Evaluation of dental plaque by quantitative digital image analysis system].

    PubMed

    Huang, Z; Luan, Q X

    2016-04-18

    To analyze the plaque staining image by using image analysis software, to verify the maneuverability, practicability and repeatability of this technique, and to evaluate the influence of different plaque stains. In the study, 30 volunteers were enrolled from the new dental students of Peking University Health Science Center in accordance with the inclusion criteria. The digital images of the anterior teeth were acquired after plaque stained according to filming standardization.The image analysis was performed using Image Pro Plus 7.0, and the Quigley-Hein plaque indexes of the anterior teeth were evaluated. The plaque stain area percentage and the corresponding dental plaque index were highly correlated,and the Spearman correlation coefficient was 0.776 (P<0.01). Intraclass correlation coefficients of the tooth area and plaque area which two researchers used the software to calculate were 0.956 and 0.930 (P<0.01).The Bland-Altman analysis chart showed only a few spots outside the 95% consistency boundaries. The different plaque stains image analysis results showed that the difference of the tooth area measurements was not significant, while the difference of the plaque area measurements significant (P<0.01). This method is easy in operation and control,highly related to the calculated percentage of plaque area and traditional plaque index, and has good reproducibility.The different plaque staining method has little effect on image segmentation results.The sensitive plaque stain for image analysis is suggested.

  18. Web-based psychometric evaluation of image quality

    NASA Astrophysics Data System (ADS)

    Sprow, Iris; Baranczuk, Zofia; Stamm, Tobias; Zolliker, Peter

    2009-01-01

    The measurement of image quality requires the judgement by the human visual system. This paper describes a psycho-visual test technique that uses the internet as a test platform to identify image quality in a more time-effective manner, comparing the visual response data with the results from the same test in a lab-based environment and estimate the usefulness of the internet as a platform for scaling studies.

  19. Night vision imaging system lighting evaluation methodology

    NASA Astrophysics Data System (ADS)

    Task, H. Lee; Pinkus, Alan R.; Barbato, Maryann H.; Hausmann, Martha A.

    2005-05-01

    In order for night vision goggles (NVGs) to be effective in aircraft operations, it is necessary for the cockpit lighting and displays to be NVG compatible. It has been assumed that the cockpit lighting is compatible with NVGs if the radiance values are compliant with the limits listed in Mil-L-85762A and Mil-Std-3009. However, these documents also describe a NVG-lighting compatibility field test procedure that is based on visual acuity. The objective of the study described in this paper was to determine how reliable and precise the visual acuity-based (VAB) field evaluation method is and compare it to a VAB method that employs less expensive equipment. In addition, an alternative, objective method of evaluating compatibility of the cockpit lighting was investigated. An inexpensive cockpit lighting simulator was devised to investigate two different interference conditions and six different radiance levels per condition. This paper describes the results, which indicate the objective method, based on light output of the NVGs, is more precise and reliable than the visual acuity-based method. Precision and reliability were assessed based on a probability of rejection (of the lighting system) function approach that was developed specifically for this study.

  20. Evaluating Satiated Copepod Behavioral Responses to Thin Layer Flow Structure

    NASA Astrophysics Data System (ADS)

    True, Aaron C.; Webster, Donald R.; Weissburg, Marc J.; Yen, Jeannette

    2011-11-01

    Zooplankton exploit a variety of chemical and fluid mechanical cues in foraging, mate-seeking, and habitat partitioning contexts. To examine the influence of environmental cues on zooplankton aggregations in coastal marine thin layers, a laboratory thin layer mimic was built. The apparatus uses a laminar, planar jet (the Bickley jet) to produce ecologically-relevant layers of chemical (beneficial and harmful phytoplankton) and fluid mechanical (shear strain rate) cues for zooplankton behavioral assays. Particle image velocimetry (PIV) and laser-induced fluorescence (LIF) were employed to fully quantify the spatial structure of the chemical and fluid mechanical cues, ensuring a close match to in situ conditions and allowing for investigations into threshold cue levels responsible for inducing behavioral responses. Evaluating the effect of hunger level on behavioral responses is particularly important for producing accurate individual-based simulations of zooplankton population dynamics. Behavioral assays with the calanoid copepod Temora longicornis have produced digitized trajectories and, subsequently, path kinematics. Observed behaviors include increased turn frequency and decreased relative swimming speed, which result in increased residence time in the free jet shear layer. Cue-induced individual behaviors have the potential to produce population-scale aggregations.

  1. An entropy-based objective evaluation method for image segmentation

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Fritts, Jason E.; Goldman, Sally A.

    2003-12-01

    Accurate image segmentation is important for many image, video and computer vision applications. Over the last few decades, many image segmentation methods have been proposed. However, the results of these segmentation methods are usually evaluated only visually, qualitatively, or indirectly by the effectiveness of the segmentation on the subsequent processing steps. Such methods are either subjective or tied to particular applications. They do not judge the performance of a segmentation method objectively, and cannot be used as a means to compare the performance of different segmentation techniques. A few quantitative evaluation methods have been proposed, but these early methods have been based entirely on empirical analysis and have no theoretical grounding. In this paper, we propose a novel objective segmentation evaluation method based on information theory. The new method uses entropy as the basis for measuring the uniformity of pixel characteristics (luminance is used in this paper) within a segmentation region. The evaluation method provides a relative quality score that can be used to compare different segmentations of the same image. This method can be used to compare both various parameterizations of one particular segmentation method as well as fundamentally different segmentation techniques. The results from this preliminary study indicate that the proposed evaluation method is superior to the prior quantitative segmentation evaluation techniques, and identify areas for future research in objective segmentation evaluation.

  2. Adaptive optics and phase diversity imaging for responsive space applications.

    SciTech Connect

    Smith, Mark William; Wick, David Victor

    2004-11-01

    The combination of phase diversity and adaptive optics offers great flexibility. Phase diverse images can be used to diagnose aberrations and then provide feedback control to the optics to correct the aberrations. Alternatively, phase diversity can be used to partially compensate for aberrations during post-detection image processing. The adaptive optic can produce simple defocus or more complex types of phase diversity. This report presents an analysis, based on numerical simulations, of the efficiency of different modes of phase diversity with respect to compensating for specific aberrations during post-processing. It also comments on the efficiency of post-processing versus direct aberration correction. The construction of a bench top optical system that uses a membrane mirror as an active optic is described. The results of characterization tests performed on the bench top optical system are presented. The work described in this report was conducted to explore the use of adaptive optics and phase diversity imaging for responsive space applications.

  3. Accommodation response measurements for integral 3D image

    NASA Astrophysics Data System (ADS)

    Hiura, H.; Mishina, T.; Arai, J.; Iwadate, Y.

    2014-03-01

    We measured accommodation responses under integral photography (IP), binocular stereoscopic, and real object display conditions, and viewing conditions of binocular and monocular viewing conditions. The equipment we used was an optometric device and a 3D display. We developed the 3D display for IP and binocular stereoscopic images that comprises a high-resolution liquid crystal display (LCD) and a high-density lens array. The LCD has a resolution of 468 dpi and a diagonal size of 4.8 inches. The high-density lens array comprises 106 x 69 micro lenses that have a focal length of 3 mm and diameter of 1 mm. The lenses are arranged in a honeycomb pattern. The 3D display was positioned 60 cm from an observer under IP and binocular stereoscopic display conditions. The target was presented at eight depth positions relative to the 3D display: 15, 10, and 5 cm in front of the 3D display, on the 3D display panel, and 5, 10, 15 and 30 cm behind the 3D display under the IP and binocular stereoscopic display conditions. Under the real object display condition, the target was displayed on the 3D display panel, and the 3D display was placed at the eight positions. The results suggest that the IP image induced more natural accommodation responses compared to the binocular stereoscopic image. The accommodation responses of the IP image were weaker than those of a real object; however, they showed a similar tendency with those of the real object under the two viewing conditions. Therefore, IP can induce accommodation to the depth positions of 3D images.

  4. Metabolic PET Imaging in Cancer Detection and Therapy Response

    PubMed Central

    Zhu, Aizhi; Lee, Daniel; Shim, Hyunsuk

    2010-01-01

    Positron emission tomography (PET) is a noninvasive imaging technique that provides a functional or metabolic assessment of normal tissue or disease conditions. 18F-fluorodeoxyglucose PET imaging (FDG-PET) is widely used clinically for tumor imaging due to increased glucose metabolism in most types of tumors, and has been shown to improve the diagnosis and subsequent treatment of cancers. In this chapter, we review its use in cancer diagnosis, staging, restaging, and assessment of response to treatment. In addition, other metabolic PET imaging agents in research or clinical trial stages are discussed, including amino acid analogs based on increased protein synthesis, and choline, which is based on increased membrane lipid synthesis. Amino acid analogs and choline are more specific to tumor cells than FDG, so they play an important role in differentiating cancers from benign conditions and in the diagnosis of cancers with low FDG uptake or high background FDG uptake. For decades, researchers have shown that tumors have altered metabolic profiles and display elevated uptake of glucose, amino acids, and lipids, which can be used for cancer diagnosis and monitoring of the therapeutic response with excellent signal-to-noise ratios. PMID:21362516

  5. Quantitative evaluation of activation state in functional brain imaging.

    PubMed

    Hu, Zhenghui; Ni, Pengyu; Liu, Cong; Zhao, Xiaohu; Liu, Huafeng; Shi, Pengcheng

    2012-10-01

    Neuronal activity can evoke the hemodynamic change that gives rise to the observed functional magnetic resonance imaging (fMRI) signal. These increases are also regulated by the resting blood volume fraction (V (0)) associated with regional vasculature. The activation locus detected by means of the change in the blood-oxygen-level-dependent (BOLD) signal intensity thereby may deviate from the actual active site due to varied vascular density in the cortex. Furthermore, conventional detection techniques evaluate the statistical significance of the hemodynamic observations. In this sense, the significance level relies not only upon the intensity of the BOLD signal change, but also upon the spatially inhomogeneous fMRI noise distribution that complicates the expression of the results. In this paper, we propose a quantitative strategy for the calibration of activation states to address these challenging problems. The quantitative assessment is based on the estimated neuronal efficacy parameter [Formula: see text] of the hemodynamic model in a voxel-by-voxel way. It is partly immune to the inhomogeneous fMRI noise by virtue of the strength of the optimization strategy. Moreover, it is easy to incorporate regional vascular information into the activation detection procedure. By combining MR angiography images, this approach can remove large vessel contamination in fMRI signals, and provide more accurate functional localization than classical statistical techniques for clinical applications. It is also helpful to investigate the nonlinear nature of the coupling between synaptic activity and the evoked BOLD response. The proposed method might be considered as a potentially useful complement to existing statistical approaches.

  6. Comprehensive computerized medical imaging: interim hypothetical economic evaluation

    NASA Astrophysics Data System (ADS)

    Warburton, Rebecca N.; Fisher, Paul D.; Nosil, Josip

    1990-08-01

    The 422-bed Victoria General Hospital (VGH) and Siemens Electric Limited have since 1983 been piloting the implementation of comprehensive computerized medical imaging, including digital acquisition of diagnostic images, in British Columbia. Although full PACS is not yet in place at VGH, experience to date habeen used to project annual cost figures (including capital replacement) for a fully-computerized department. The resulting economic evaluation has been labelled hypothetical to emphasize that some key cost components were estimated rather than observed; this paper presents updated cost figures based on recent revisions to proposed departmental equipment configuration which raised the cost of conventional imaging equipment by 0.3 million* and lowered the cost of computerized imaging equipment by 0.8 million. Compared with conventional diagnostic imaging, computerized imaging appears to raise overall annual costs at VGH by nearly 0.7 million, or 11.6%; this is more favourable than the previous results, which indicated extra annual costs of 1 million (16.9%). Sensitivity analysis still indicates that all reasonable changes in the underlying assumptions result in higher costs for computerized imaging than for conventional imaging. Computerized imaging offers lower radiation exposure to patients, shorter waiting times, and other potential advantages, but as yet the price of obtaining these benefits remains substantial.

  7. A biological phantom for evaluation of CT image reconstruction algorithms

    NASA Astrophysics Data System (ADS)

    Cammin, J.; Fung, G. S. K.; Fishman, E. K.; Siewerdsen, J. H.; Stayman, J. W.; Taguchi, K.

    2014-03-01

    In recent years, iterative algorithms have become popular in diagnostic CT imaging to reduce noise or radiation dose to the patient. The non-linear nature of these algorithms leads to non-linearities in the imaging chain. However, the methods to assess the performance of CT imaging systems were developed assuming the linear process of filtered backprojection (FBP). Those methods may not be suitable any longer when applied to non-linear systems. In order to evaluate the imaging performance, a phantom is typically scanned and the image quality is measured using various indices. For reasons of practicality, cost, and durability, those phantoms often consist of simple water containers with uniform cylinder inserts. However, these phantoms do not represent the rich structure and patterns of real tissue accurately. As a result, the measured image quality or detectability performance for lesions may not reflect the performance on clinical images. The discrepancy between estimated and real performance may be even larger for iterative methods which sometimes produce "plastic-like", patchy images with homogeneous patterns. Consequently, more realistic phantoms should be used to assess the performance of iterative algorithms. We designed and constructed a biological phantom consisting of porcine organs and tissue that models a human abdomen, including liver lesions. We scanned the phantom on a clinical CT scanner and compared basic image quality indices between filtered backprojection and an iterative reconstruction algorithm.

  8. Evaluation Of Algorithms For A Squid Detector Neuromagnetic Imaging System

    NASA Astrophysics Data System (ADS)

    Leahy, Richard; Jeffe, Brian; Singh, Manbir; Brechner, Ricardo

    1987-01-01

    The SQUID based biomagnetometer has been widely used to measure the external magnetic field produced by neural activity. In this paper we consider the viability of using this data to reconstruct three dimensional neuromagnetic images (NMI) of an equivalent electrical current distribution within the brain which would produce the measured magnetic field. The fundamental limitations on this mode of imaging are evaluated and possible physical models and mathematical formulations of the problem are proposed. Several algorithms often used in medical image reconstruction are applied to the problem and their performance evaluated. We conclude that the reconstruction problem is highly ill-posed, and that conventional image reconstruction algorithms are inadequate for 3-D NMI. A class of solutions we call 'minimum dipole' is shown to provide more accurate reconstructions of simple current distributions.

  9. Color normalization for robust evaluation of microscopy images

    NASA Astrophysics Data System (ADS)

    Švihlík, Jan; Kybic, Jan; Habart, David

    2015-09-01

    This paper deals with color normalization of microscopy images of Langerhans islets in order to increase robustness of the islet segmentation to illumination changes. The main application is automatic quantitative evaluation of the islet parameters, useful for determining the feasibility of islet transplantation in diabetes. First, background illumination inhomogeneity is compensated and a preliminary foreground/background segmentation is performed. The color normalization itself is done in either lαβ or logarithmic RGB color spaces, by comparison with a reference image. The color-normalized images are segmented using color-based features and pixel-wise logistic regression, trained on manually labeled images. Finally, relevant statistics such as the total islet area are evaluated in order to determine the success likelihood of the transplantation.

  10. Image quality evaluation with a contour-based perceptual model

    NASA Astrophysics Data System (ADS)

    Grogan, Timothy A.; Keene, David P.

    1992-08-01

    A computational model for the human perception of image brightness utilizing both local and global interactions has been advanced by Grossberg, Mingolla and Todorovic. A simulation of this multi-layer, non-linear recurrent network model can be used to assess perceived image quality. The model is validated by examining the simulation of a classical brightness perception phenomenon, in particular, Glass patterns. Results of a comparative evaluation of three halftoning algorithms are offered which indicate that the model is useful for the evaluation of image processing algorithms. Human subjects ranked the quality of the images halftoned with each of three different algorithms at two different viewing distances. After processing by the brightness perception model, ranking of objective measures of the simulated model output correspond with the rankings assigned by human observers.

  11. Multiparametric Assessment of Treatment Response in High-Grade Soft-Tissue Sarcomas with Anatomic and Functional MR Imaging Sequences

    PubMed Central

    Soldatos, Theodoros; Ahlawat, Shivani; Montgomery, Elizabeth; Chalian, Majid; Jacobs, Michael A.

    2016-01-01

    Purpose To determine the added value of quantitative diffusion-weighted and dynamic contrast material–enhanced imaging to conventional magnetic resonance (MR) imaging for assessment of the response of soft-tissue sarcomas to neoadjuvant therapy. Materials and Methods MR imaging examinations in 23 patients with soft-tissue sarcomas who had undergone neoadjuvant therapy were reviewed by two readers during three sessions: conventional imaging (T1-weighted, fluid-sensitive, static postcontrast T1-weighted), conventional with diffusion-weighted imaging, and conventional with diffusion-weighted and dynamic contrast-enhanced imaging. For each session, readers recorded imaging features and determined treatment response. Interobserver agreement was assessed and receiver operating characteristic analysis was performed to evaluate the accuracy of each session for determining response by using results of the histologic analysis as the reference standard. Good response was defined as less than or equal to 5% residual viable tumor. Results Of the 23 sarcomas, four (17.4%) showed good histologic response (three of four with >95% granulation tissue and <5% necrosis, one of four with 95% necrosis and <5% viable tumor) and 19 (82.6%) showed poor response (viable tumor range, 10%–100%). Interobserver agreement was substantial or excellent for imaging features in all sequences (k = 0.789–1.000). Receiver operating characteristic analysis showed an increase in diagnostic performance with the addition of diffusion-weighted and dynamic contrast-enhanced MR imaging for prediction of response compared with that for conventional imaging alone (areas under the curve, 0.500, 0.676, 0.821 [reader 1] and 0.506, 0.704, 0.833 [reader 2], respectively). Conclusion Adding functional sequences to the conventional MR imaging protocol increases the sensitivity of MR imaging for determining treatment response in soft-tissue sarcomas. © RSNA, 2015 PMID:26390048

  12. Dynamic Chest Image Analysis: Evaluation of Model-Based Pulmonary Perfusion Analysis With Pyramid Images

    DTIC Science & Technology

    2007-11-02

    Image Analysis aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the Dynamic Pulmonary Imaging technique 18,5,17,6. We have proposed and evaluated a multiresolutional method with an explicit ventilation model based on pyramid images for ventilation analysis. We have further extended the method for ventilation analysis to pulmonary perfusion. This paper focuses on the clinical evaluation of our method for

  13. Meat quality evaluation by hyperspectral imaging technique: an overview.

    PubMed

    Elmasry, Gamal; Barbin, Douglas F; Sun, Da-Wen; Allen, Paul

    2012-01-01

    During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread

  14. Comparison and evaluation of retrospective intermodality image registration techniques

    NASA Astrophysics Data System (ADS)

    West, Jay B.; Fitzpatrick, J. Michael; Wang, Matthew Y.; Dawant, Benoit M.; Maurer, Calvin R., Jr.; Kessler, Robert M.; Maciunas, Robert J.; Barillot, Christian; Lemoine, Didier; Collignon, Andre M. F.; Maes, Frederik; Suetens, Paul; Vandermeulen, Dirk; van den Elsen, Petra A.; Hemler, Paul F.; Napel, Sandy; Sumanaweera, Thilaka S.; Harkness, Beth A.; Hill, Derek L.; Studholme, Colin; Malandain, Gregoire; Pennec, Xavier; Noz, Marilyn E.; Maguire, Gerald Q., Jr.; Pollack, Michael; Pelizzari, Charles A.; Robb, Richard A.; Hanson, Dennis P.; Woods, Roger P.

    1996-04-01

    All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a 'gold standard' to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities -- CT, MR, and PET -- were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple 'regions of interest,' i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C' in CT or PET. To this point the retrospective registration is then applied, producing C' in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C'. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an

  15. LWD borehole images/dips aid offshore California evaluation

    SciTech Connect

    Young, R.A.; Lovell, J.R.; Rosthal, R.A.; Buffington, L.; Arceneaux, C. Jr.

    1996-04-01

    Quantitative, fullbore, azimuthal resistivity images of the borehole wall, acquired while drilling, can reveal large-scale structural bedding, fractures, faults, unconformities and other useful geologic events. While these images cannot resolve fine structural features or stratigraphic details, they can help identify those intervals requiring higher resolution wireline logging after drilling, and can be used to calculate general structural dips prior to wireline image/dipmeter runs. These images and dips have proven useful for time-critical drilling decisions and for subsequent geological interpretation and formation evaluation. This article presents discussions on: data acquisition at the bit with the Resistivity-at-the-Bit (RAB) tool, including tool functions and depth control, specific benefits derived from while-drilling resistivity images in two offshore California wells, and a favorable RAB outlook including a new RAB method for calculating high angle dips.

  16. Behavioral Response Research Evaluation Workshop (BRREW)

    DTIC Science & Technology

    2015-09-30

    N000141512664 http://www.creem.st-and.ac.uk LONG-TERM GOALS The behavioral response of marine mammals to Navy sonar exposure has been a research...The overall objective is to review the status and future of research into behavioral responses of marine mammals to naval sonar exposure in order to...are to: 1. undertake a science-based synthesis of the current state of knowledge on the behavioral response of marine mammals to Navy sonar exposure

  17. Idiopathic Chronic Parotitis: Imaging Findings and Sialendoscopic Response.

    PubMed

    Heineman, Thomas E; Kacker, Ashutosh; Kutler, David I

    2015-01-01

    The purpose of this study was to correlate imaging and sialendoscopic findings to therapeutic response in patients with idiopathic chronic parotitis. We retrospectively reviewed 122 consecutive sialendoscopies performed in an academic medical center by two surgeons between 2008 and 2013. Forty-one (34%) and 54 (44%) patients were excluded on the basis of having parotid or submandibular sialolith, respectively. Nineteen cases were included in the study with idiopathic chronic parotitis. There was a median follow-up of 5 months. Computed tomography (CT) imaging had a sensitivity and specificity of 80.0 and 71.4%, respectively, for predicting abnormal findings on sialendoscopy, while magnetic resonance imaging (MRI) had 100% accuracy in a small set of cases. In glands with noticeable pathology present on preoperative imaging or sialendoscopy, 11 out of 12 glands (92%) treated experienced symptomatic improvement, while 3 out of 7 glands (43%) without pathology on imaging or endoscopy experienced symptomatic improvement (p = 0.038). Sialendoscopy for the treatment of idiopathic chronic parotid disease can improve pain and swelling with a higher frequency of success in patients with abnormalities noted on endoscopy. CT and MRI have a moderate degree of accuracy in predicting which patients will benefit from therapeutic sialendoscopy. © 2015 S. Karger AG, Basel.

  18. Ultrasound image quality assessment: a framework for evaluation of clinical image quality

    NASA Astrophysics Data System (ADS)

    Hemmsen, Martin Christian; Petersen, Mads Møller; Nikolov, Svetoslav Ivanov; Nielsen, Michael Backmann; Jensen, Jørgen Arendt

    2010-03-01

    Improvement of ultrasound images should be guided by their diagnostic value. Evaluation of clinical image quality is generally performed subjectively, because objective criteria have not yet been fully developed and accepted for the evaluation of clinical image quality. Based on recommendation 500 from the International Telecommunication Union - Radiocommunication (ITU-R) for such subjective quality assessment, this work presents equipment and a methodology for clinical image quality evaluation for guiding the development of new and improved imaging. The system is based on a BK-Medical 2202 ProFocus scanner equipped with a UA2227 research interface, connected to a PC through X64-CL Express camera link. Data acquisition features subject data recording, loading/saving of exact scanner settings (for later experiment reproducibility), free access to all system parameters for beamformation and is applicable for clinical use. The free access to all system parameters enables the ability to capture standardized images as found in the clinic and experimental data from new processing or beamformation methods. The length of the data sequences is only restricted by the memory of the external PC. Data may be captured interleaved, switching between multiple setups, to maintain identical transducer, scanner, region of interest and recording time on both the experimental- and standardized images. Data storage is approximately 15.1 seconds pr. 3 sec sequence including complete scanner settings and patient information, which is fast enough to get sufficient number of scans under realistic operating conditions, so that statistical evaluation is valid and reliable.

  19. Evaluating image reconstruction methods for tumor detection in 3-dimensional whole-body PET oncology imaging.

    PubMed

    Lartizien, Carole; Kinahan, Paul E; Swensson, Richard; Comtat, Claude; Lin, Michael; Villemagne, Victor; Trébossen, Régine

    2003-02-01

    We compare 3 image reconstruction algorithms for use in 3-dimensional (3D) whole-body PET oncology imaging. We have previously shown that combining Fourier rebinning (FORE) with 2-dimensional (2D) statistical image reconstruction via the ordered-subsets expectation-maximization (OSEM) and attenuation-weighted OSEM (AWOSEM) algorithms demonstrates improvements in image signal-to-noise ratios compared with the commonly used analytic 3D reprojection (3DRP) or FORE+FBP (2D filtered backprojection) reconstruction methods. To assess the impact of these reconstruction methods on detecting and localizing small lesions, we performed a human observer study comparing the different reconstruction methods. The observer study used the same volumetric visualization software tool that is used in clinical practice, instead of a planar viewing mode as is generally used with the standard receiver operating characteristic (ROC) methodology. This change in the human evaluation strategy disallowed the use of a ROC analysis, so instead we compared the fraction of actual targets found and reported (fraction-found) and also investigated the use of an alternative free-response operating characteristic (AFROC) analysis. We used a non-Monte Carlo technique to generate 50 statistically accurate realizations of 3D whole-body PET data based on an extended mathematic cardiac torso (MCAT) phantom and with noise levels typical of clinical scans performed on a PET scanner. To each realization, we added 7 randomly located 1-cm-diameter lesions (targets) whose contrasts were varied to sample the range of detectability. These targets were inserted in 3 organs of interest: lungs, liver, and soft tissues. The images were reconstructed with 3 reconstruction strategies (FORE+OSEM, FORE+AWOSEM, and FORE+FBP). Five human observers reported (localized and rated) 7 targets within each volume image. An observer's performance accuracy with each algorithm was measured, as a function of the lesion contrast and

  20. Evaluation of clinical image processing algorithms used in digital mammography.

    PubMed

    Zanca, Federica; Jacobs, Jurgen; Van Ongeval, Chantal; Claus, Filip; Celis, Valerie; Geniets, Catherine; Provost, Veerle; Pauwels, Herman; Marchal, Guy; Bosmans, Hilde

    2009-03-01

    Screening is the only proven approach to reduce the mortality of breast cancer, but significant numbers of breast cancers remain undetected even when all quality assurance guidelines are implemented. With the increasing adoption of digital mammography systems, image processing may be a key factor in the imaging chain. Although to our knowledge statistically significant effects of manufacturer-recommended image processings have not been previously demonstrated, the subjective experience of our radiologists, that the apparent image quality can vary considerably between different algorithms, motivated this study. This article addresses the impact of five such algorithms on the detection of clusters of microcalcifications. A database of unprocessed (raw) images of 200 normal digital mammograms, acquired with the Siemens Novation DR, was collected retrospectively. Realistic simulated microcalcification clusters were inserted in half of the unprocessed images. All unprocessed images were subsequently processed with five manufacturer-recommended image processing algorithms (Agfa Musica 1, IMS Raffaello Mammo 1.2, Sectra Mamea AB Sigmoid, Siemens OPVIEW v2, and Siemens OPVIEW v1). Four breast imaging radiologists were asked to locate and score the clusters in each image on a five point rating scale. The free-response data were analyzed by the jackknife free-response receiver operating characteristic (JAFROC) method and, for comparison, also with the receiver operating characteristic (ROC) method. JAFROC analysis revealed highly significant differences between the image processings (F = 8.51, p < 0.0001), suggesting that image processing strongly impacts the detectability of clusters. Siemens OPVIEW2 and Siemens OPVIEW1 yielded the highest and lowest performances, respectively. ROC analysis of the data also revealed significant differences between the processing but at lower significance (F = 3.47, p = 0.0305) than JAFROC. Both statistical analysis methods revealed that the

  1. Evaluation of color error and noise on simulated images

    NASA Astrophysics Data System (ADS)

    Mornet, Clémence; Vaillant, Jérôme; Decroux, Thomas; Hérault, Didier; Schanen, Isabelle

    2010-01-01

    The evaluation of CMOS sensors performance in terms of color accuracy and noise is a big challenge for camera phone manufacturers. On this paper, we present a tool developed with Matlab at STMicroelectronics which allows quality parameters to be evaluated on simulated images. These images are computed based on measured or predicted Quantum Efficiency (QE) curves and noise model. By setting the parameters of integration time and illumination, the tool optimizes the color correction matrix (CCM) and calculates the color error, color saturation and signal-to-noise ratio (SNR). After this color correction optimization step, a Graphics User Interface (GUI) has been designed to display a simulated image at a chosen illumination level, with all the characteristics of a real image taken by the sensor with the previous color correction. Simulated images can be a synthetic Macbeth ColorChecker, for which reflectance of each patch is known, or a multi-spectral image, described by the reflectance spectrum of each pixel or an image taken at high-light level. A validation of the results has been performed with ST under development sensors. Finally we present two applications one based on the trade-offs between color saturation and noise by optimizing the CCM and the other based on demosaicking SNR trade-offs.

  2. Cardiac imaging approaches to evaluate drug-induced myocardial dysfunction

    PubMed Central

    Christian, Jennifer B.; Finkle, John K.; Ky, Bonnie; Douglas, Pamela S.; Gutstein, David E.; Hockings, Paul D.; Lainee, Pierre; Lenihan, Daniel J.; Mason, Jay W.; Sager, Philip T.; Todaro, Thomas G.; Hicks, Karen A.; Kane, Robert C.; Ko, Hon-Sum; Lindenfeld, JoAnn; Michelson, Eric L.; Milligan, James; Munley, Jiefen Y.; Raichlen, Joel S.; Shahlaee, Amir; Strnadova, Colette; Ye, Brenda; Turner, J. Rick

    2013-01-01

    The ability to make informed benefit-risk assessments for potentially cardiotoxic new compounds is of considerable interest and importance at the public health, drug development, and individual patient levels. Cardiac imaging approaches in the evaluation of drug-induced myocardial dysfunction will likely play an increasing role. However, the optimal choice of myocardial imaging modality and the recommended frequency of monitoring are undefined. These decisions are complicated by the array of imaging techniques, which have varying sensitivities, specificities, availabilities, local expertise, safety, and costs, and by the variable time-course of tissue damage, functional myocardial depression, or recovery of function. This White Paper summarizes scientific discussions of members of the Cardiac Safety Research Consortium on the main factors to consider when selecting nonclinical and clinical cardiac function imaging techniques in drug development. We focus on 3 commonly used imaging modalities in the evaluation of cardiac function: echocardiography, magnetic resonance imaging, and radionuclide (nuclear) imaging and highlight areas for future research. PMID:23194484

  3. Computer-aided breast MR image feature analysis for prediction of tumor response to chemotherapy

    SciTech Connect

    Aghaei, Faranak; Tan, Maxine; Liu, Hong; Zheng, Bin; Hollingsworth, Alan B.; Qian, Wei

    2015-11-15

    Purpose: To identify a new clinical marker based on quantitative kinetic image features analysis and assess its feasibility to predict tumor response to neoadjuvant chemotherapy. Methods: The authors assembled a dataset involving breast MR images acquired from 68 cancer patients before undergoing neoadjuvant chemotherapy. Among them, 25 patients had complete response (CR) and 43 had partial and nonresponse (NR) to chemotherapy based on the response evaluation criteria in solid tumors. The authors developed a computer-aided detection scheme to segment breast areas and tumors depicted on the breast MR images and computed a total of 39 kinetic image features from both tumor and background parenchymal enhancement regions. The authors then applied and tested two approaches to classify between CR and NR cases. The first one analyzed each individual feature and applied a simple feature fusion method that combines classification results from multiple features. The second approach tested an attribute selected classifier that integrates an artificial neural network (ANN) with a wrapper subset evaluator, which was optimized using a leave-one-case-out validation method. Results: In the pool of 39 features, 10 yielded relatively higher classification performance with the areas under receiver operating characteristic curves (AUCs) ranging from 0.61 to 0.78 to classify between CR and NR cases. Using a feature fusion method, the maximum AUC = 0.85 ± 0.05. Using the ANN-based classifier, AUC value significantly increased to 0.96 ± 0.03 (p < 0.01). Conclusions: This study demonstrated that quantitative analysis of kinetic image features computed from breast MR images acquired prechemotherapy has potential to generate a useful clinical marker in predicting tumor response to chemotherapy.

  4. Clinical applications of advanced magnetic resonance imaging techniques for arthritis evaluation

    PubMed Central

    Martín Noguerol, Teodoro; Luna, Antonio; Gómez Cabrera, Marta; Riofrio, Alexie D

    2017-01-01

    Magnetic resonance imaging (MRI) has allowed a comprehensive evaluation of articular disease, increasing the detection of early cartilage involvement, bone erosions, and edema in soft tissue and bone marrow compared to other imaging techniques. In the era of functional imaging, new advanced MRI sequences are being successfully applied for articular evaluation in cases of inflammatory, infectious, and degenerative arthropathies. Diffusion weighted imaging, new fat suppression techniques such as DIXON, dynamic contrast enhanced-MRI, and specific T2 mapping cartilage sequences allow a better understanding of the physiopathological processes that underlie these different arthropathies. They provide valuable quantitative information that aids in their differentiation and can be used as potential biomarkers of articular disease course and treatment response. PMID:28979849

  5. Predictive imaging of chemotherapeutic response in a transgenic mouse model of pancreatic cancer

    PubMed Central

    Wang, Ping; Yoo, Byunghee; Sherman, Sarah; Mukherjee, Pinku; Ross, Alana; Pantazopoulos, Pamela; Petkova, Victoria; Farrar, Christian; Medarova, Zdravka; Moore, Anna

    2016-01-01

    The underglycosylated mucin 1 tumor antigen (uMUC1) is a biomarker that forecasts the progression of adenocarcinomas. In this study, we evaluated the utility of a dual-modality molecular imaging approach based on targeting uMUC1 for monitoring chemotherapeutic response in a transgenic murine model of pancreatic cancer (KCM triple transgenic mice). An uMUC1-specific contrast agent (MN-EPPT) was synthesized for use with magnetic resonance imaging (MRI) and fluorescence optical imaging. It consisted of dextran-coated iron oxide nanoparticles conjugated to the near infrared fluorescent dye Cy5.5 and to a uMUC1-specific peptide (EPPT). KCM triple transgenic mice were given gemcitabine as chemotherapy while control animals received saline injections following the same schedule. Changes in uMUC1 levels following chemotherapy were monitored using T2-weighted MRI and optical imaging before and 24 hr after injection of the MN-EPPT. uMUC1 expression in tumors from both groups was evaluated by histology and qRT-PCR. We observed that the average delta-T2 in the gemcitabine-treated group was significantly reduced compared to the control group indicating lower accumulation of MN-EPPT, and correspondingly, a lower level of uMUC1 expression. In vivo optical imaging confirmed the MRI findings. Fluorescence microscopy of pancreatic tumor sections showed a lower level of uMUC1 expression in the gemcitabine-treated group compared to the control, which was confirmed by qRT-PCR. Our data proved that changes in uMUC1 expression after gemcitabine chemotherapy could be evaluated using MN-EPPT-enhanced in vivo MR and optical imaging. These results suggest that the uMUC1-targeted imaging approach could provide a useful tool for the predictive assessment of therapeutic response. PMID:26996122

  6. Complications of renal transplantation: evaluation with US and radionuclide imaging.

    PubMed

    Brown, E D; Chen, M Y; Wolfman, N T; Ott, D J; Watson, N E

    2000-01-01

    Following renal transplantation, patients are often evaluated with ultrasonography (US) or radionuclide imaging to assess renal function and the presence of possible complications. Both modalities are inexpensive, noninvasive, and nonnephrotoxic. A basic understanding of the surgical techniques commonly used for renal transplantation is useful when imaging these patients in order to recognize complications and to direct further imaging or intervention. The most frequent complications of renal transplantation include perinephric fluid collections; decreased renal function; and abnormalities of the vasculature, collecting system, and renal parenchyma. Perinephric fluid collections are common following transplantation, and their clinical significance depends on the type, location, size, and growth of the fluid collection, features that are well-evaluated with US. Causes of diminished renal function include acute tubular necrosis, rejection, and toxicity from medications. Radionuclide imaging is the most useful modality for assessing renal function. Vascular complications of transplantation include occlusion or stenosis of the arterial or venous supply, arteriovenous fistulas, and pseudoaneurysms. Although the standard for evaluating these vascular complications is angiography, US is an excellent noninvasive method for screening. Other transplant complications such as abnormalities of the collecting system and renal parenchyma are well-evaluated with both radionuclide imaging and US.

  7. Study of Fish Response Using Particle Image Velocimetry and High-Speed, High-Resolution Imaging

    SciTech Connect

    Deng, Zhiqun; Richmond, Marshall C.; Guensch, Gregory R.; Mueller, Robert P.

    2004-10-23

    Existing literature of previous particle image velocimetry (PIV) studies of fish swimming has been reviewed. Historically, most of the studies focused on the performance evaluation of freely swimming fish. Technological advances over the last decade, especially the development of digital particle image velocimetry (DPIV) technique, make possible more accurate, quantitative descriptions of the flow patterns adjacent to the fish and in the wake behind the fins and tail, which are imperative to decode the mechanisms of drag reduction and propulsive efficiency. For flows generated by different organisms, the related scales and flow regimes vary significantly. For small Reynolds numbers, viscosity dominates; for very high Reynolds numbers, inertia dominates, and three-dimensional complexity occurs. The majority of previous investigations dealt with the lower end of Reynolds number range. The fish of our interest, such as rainbow trout and spring and fall chinook salmon, fall into the middle range, in which neither viscosity nor inertia is negligible, and three-dimensionality has yet to dominate. Feasibility tests have proven the applicability of PIV to flows around fish. These tests have shown unsteady vortex shedding in the wake, high vorticity region and high stress region, with the highest in the pectoral area. This evident supports the observations by Nietzel et al. (2000) and Deng et al. (2004) that the operculum are most vulnerable to damage from the turbulent shear flow, because they are easily pried open, and the large vorticity and shear stress can lift and tear off scales, rupture or dislodge eyes, and damage gills. In addition, the unsteady behavior of the vortex shedding in the wake implies that injury to fish by the instantaneous flow structures would likely be much higher than the injury level estimated using the average values of the dynamics parameters. Based on existing literature, our technological capability, and relevance and practicability to

  8. Can Routine Imaging After Neoadjuvant Chemotherapy in Breast Cancer Predict Pathologic Complete Response?

    PubMed

    Schaefgen, B; Mati, M; Sinn, H P; Golatta, M; Stieber, A; Rauch, G; Hennigs, A; Richter, H; Domschke, C; Schuetz, F; Sohn, C; Schneeweiss, A; Heil, Joerg

    2016-03-01

    This study evaluated breast imaging procedures for predicting pathologic complete response (pCR = ypT0) after neoadjuvant chemotherapy (NACT) for breast cancer to challenge surgery as a diagnostic procedure after NACT. This retrospective, exploratory, monocenter study included 150 invasive breast cancers treated by NACT. The patients received magnetic resonance imaging (MRI), mammography (MGR), and ultrasound (US). The results were classified in three response subgroups according to response evaluation criteria in solid tumors. To incorporate specific features of MRI and MGR, an additional category [clinical near complete response (near-cCR)] was defined. Residual cancer in imaging and pathology was defined as a positive result. Negative predictive values (NPVs), false-negative rates (FNRs), and false-positive rates (FPRs) of all imaging procedures were analyzed for the whole cohort and for triple-negative (TN), HER2-positive (HER2+), and HER2-negative/hormone-receptor-positive (HER2-/HR+) cancers, respectively. In 46 cases (31%), pCR (ypT0) was achieved. Clinical complete response (cCR) and near-cCR showed nearly the same NPVs and FNRs. The NPV was highest with 61% for near-cCR in MRI and lowest with 44% for near-cCR in MGR for the whole cohort. The FNRs ranged from 4 to 25% according to different imaging methods. The MRI performance seemed to be superior, especially in TN cancers (NPV 94%; FNR 5%). The lowest FPR was 10 % in MRI, and the highest FPR was 44% in US. Neither MRI nor MGR or US can diagnose a pCR (ypT0) with sufficient accuracy to replace pathologic diagnosis of the surgical excision specimen.

  9. Nonlinear response of lipid-shelled microbubbles to coded excitation: implications for noninvasive atherosclerosis imaging

    NASA Astrophysics Data System (ADS)

    Shekhar, Himanshu; Doyley, Marvin M.

    2013-03-01

    Nonlinear (subharmonic/harmonic) imaging with ultrasound contrast agents (UCA) could characterize the vasa vasorum, which could help assess the risk associated with atherosclerosis. However, the sensitivity and specificity of high-frequency nonlinear imaging must be improved to enable its clinical translation. The current excitation scheme employs sine-bursts — a strategy that requires high-peak pressures to produce strong nonlinear response from UCA. In this paper, chirp-coded excitation was evaluated to assess its ability to enhance the subharmonic and harmonic response of UCA. Acoustic measurements were conducted with a pair of single-element transducers at 10-MHz transmit frequencies to evaluate the subharmonic and harmonic response of Targestar-P® (Targeson Inc., San Diego, CA, USA), a commercially available phospholipid-encapsulated contrast agent. The results of this study demonstrated a 2 - 3 fold reduction in the subharmonic threshold, and a 4 - 14 dB increase in nonlinear signal-to-noise ratio, with chirp-coded excitation. Therefore, chirp-coded excitation could be well suited for improving the imaging performance of high-frequency harmonic and subharmonic imaging.

  10. Mode imaging and loss evaluation of semiconductor waveguides

    SciTech Connect

    Mochizuki, Toshimitsu; Kim, Changsu; Yoshita, Masahiro; Nakamura, Takahiro; Akiyama, Hidefumi; Pfeiffer, Loren N.; West, Ken W.

    2014-05-15

    An imaging and loss evaluation method for semiconductor waveguides coupled with non-doped quantum wells is presented. Using the internal emission of the wells as a probe light source, the numbers and widths of the modes of waveguides with various ridge sizes were evaluated by CCD imaging, and the obtained values were consistent with effective index method calculation. Waveguide internal losses were obtained from analyses of the Fabry-Pérot fringes of waveguide emission spectra. We quantified the quality of 29 single-mode waveguide samples as an internal loss and variation of 10.2 ± 0.6  cm{sup −1}.

  11. Learning evaluation of ultrasound image segmentation using combined measures

    NASA Astrophysics Data System (ADS)

    Fang, Mengjie; Luo, Yongkang; Ding, Mingyue

    2016-03-01

    Objective evaluation of medical image segmentation is one of the important steps for proving its validity and clinical applicability. Although there are many researches presenting segmentation methods on medical image, while with few studying the evaluation methods on their results, this paper presents a learning evaluation method with combined measures to make it as close as possible to the clinicians' judgment. This evaluation method is more quantitative and precise for the clinical diagnose. In our experiment, the same data sets include 120 segmentation results of lumen-intima boundary (LIB) and media-adventitia boundary (MAB) of carotid ultrasound images respectively. And the 15 measures of goodness method and discrepancy method are used to evaluate the different segmentation results alone. Furthermore, the experimental results showed that compared with the discrepancy method, the accuracy with the measures of goodness method is poor. Then, by combining with the measures of two methods, the average accuracy and the area under the receiver operating characteristic (ROC) curve of 2 segmentation groups are higher than 93% and 0.9 respectively. And the results of MAB are better than LIB, which proved that this novel method can effectively evaluate the segmentation results. Moreover, it lays the foundation for the non-supervised segmentation evaluation system.

  12. Response Style Contamination of Student Evaluation Data

    ERIC Educational Resources Information Center

    Dolnicar, Sara; Grun, Bettina

    2009-01-01

    Student evaluation surveys provide instructors with feedback regarding development opportunities and they form the basis of promotion and tenure decisions. Student evaluations have been extensively studied, but one dimension hitherto neglected is the actual measurement aspect: which questions to ask, how to ask them, and what answer options to…

  13. Response Style Contamination of Student Evaluation Data

    ERIC Educational Resources Information Center

    Dolnicar, Sara; Grun, Bettina

    2009-01-01

    Student evaluation surveys provide instructors with feedback regarding development opportunities and they form the basis of promotion and tenure decisions. Student evaluations have been extensively studied, but one dimension hitherto neglected is the actual measurement aspect: which questions to ask, how to ask them, and what answer options to…

  14. Large-scale image region documentation for fully automated image biomarker algorithm development and evaluation.

    PubMed

    Reeves, Anthony P; Xie, Yiting; Liu, Shuang

    2017-04-01

    With the advent of fully automated image analysis and modern machine learning methods, there is a need for very large image datasets having documented segmentations for both computer algorithm training and evaluation. This paper presents a method and implementation for facilitating such datasets that addresses the critical issue of size scaling for algorithm validation and evaluation; current evaluation methods that are usually used in academic studies do not scale to large datasets. This method includes protocols for the documentation of many regions in very large image datasets; the documentation may be incrementally updated by new image data and by improved algorithm outcomes. This method has been used for 5 years in the context of chest health biomarkers from low-dose chest CT images that are now being used with increasing frequency in lung cancer screening practice. The lung scans are segmented into over 100 different anatomical regions, and the method has been applied to a dataset of over 20,000 chest CT images. Using this framework, the computer algorithms have been developed to achieve over 90% acceptable image segmentation on the complete dataset.

  15. Evaluation of image quality of a new CCD-based system for chest imaging

    NASA Astrophysics Data System (ADS)

    Sund, Patrik; Kheddache, Susanne; Mansson, Lars G.; Bath, Magnus; Tylen, Ulf

    2000-04-01

    The Imix radiography system (Qy Imix Ab, Finland)consists of an intensifying screen, optics, and a CCD camera. An upgrade of this system (Imix 2000) with a red-emitting screen and new optics has recently been released. The image quality of Imix (original version), Imix 200, and two storage-phosphor systems, Fuji FCR 9501 and Agfa ADC70 was evaluated in physical terms (DQE) and with visual grading of the visibility of anatomical structures in clinical images (141 kV). PA chest images of 50 healthy volunteers were evaluated by experienced radiologists. All images were evaluated on Siemens Simomed monitors, using the European Quality Criteria. The maximum DQE values for Imix, Imix 2000, Agfa and Fuji were 11%, 14%, 17% and 19%, respectively (141kV, 5μGy). Using the visual grading, the observers rated the systems in the following descending order. Fuji, Imix 2000, Agfa, and Imix. Thus, the upgrade to Imix 2000 resulted in higher DQE values and a significant improvement in clinical image quality. The visual grading agrees reasonably well with the DQE results; however, Imix 2000 received a better score than what could be expected from the DQE measurements. Keywords: CCD Technique, Chest Imaging, Digital Radiography, DQE, Image Quality, Visual Grading Analysis

  16. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides.

    PubMed

    Ferguson, Ian; Phillips, Andrew W; Lin, Michelle

    2017-01-01

    Although continuing medical education (CME) presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer's theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period) used a mixed linear regression model to assess whether post-conference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation) and text density (number of words per slide). A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate) were available for analysis. On average, 47.4% (SD=25.36) of slides had at least one educationally-relevant image (image fraction). Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676)=6.158, p=0.015] in the mixed linear regression model. The mean (SD) text density was 25.61 (8.14) words/slide but was not a significant predictor [F(1, 86.293)=0.55, p=0.815]. Of note, the individual speaker [χ(2)(1)=2.952, p=0.003] and speaker seniority [F(3, 59.713)=4.083, p=0.011] significantly predicted higher scores. This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer's theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation skills.

  17. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides

    PubMed Central

    Ferguson, Ian; Phillips, Andrew W.; Lin, Michelle

    2017-01-01

    Introduction Although continuing medical education (CME) presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer’s theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. Methods This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period) used a mixed linear regression model to assess whether post-conference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation) and text density (number of words per slide). Results A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate) were available for analysis. On average, 47.4% (SD=25.36) of slides had at least one educationally-relevant image (image fraction). Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676)=6.158, p=0.015] in the mixed linear regression model. The mean (SD) text density was 25.61 (8.14) words/slide but was not a significant predictor [F(1, 86.293)=0.55, p=0.815]. Of note, the individual speaker [χ2(1)=2.952, p=0.003] and speaker seniority [F(3, 59.713)=4.083, p=0.011] significantly predicted higher scores. Conclusion This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer’s theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation

  18. Imaging the DNA damage response with PET and SPECT.

    PubMed

    Knight, James C; Koustoulidou, Sofia; Cornelissen, Bart

    2017-06-01

    DNA integrity is constantly challenged by endogenous and exogenous factors that can alter the DNA sequence, leading to mutagenesis, aberrant transcriptional activity, and cytotoxicity. Left unrepaired, damaged DNA can ultimately lead to the development of cancer. To overcome this threat, a series of complex mechanisms collectively known as the DNA damage response (DDR) are able to detect the various types of DNA damage that can occur and stimulate the appropriate repair process. Each DNA damage repair pathway leads to the recruitment, upregulation, or activation of specific proteins within the nucleus, which, in some cases, can represent attractive targets for molecular imaging. Given the well-established involvement of DDR during tumorigenesis and cancer therapy, the ability to monitor these repair processes non-invasively using nuclear imaging techniques may facilitate the earlier detection of cancer and may also assist in monitoring response to DNA damaging treatment. This review article aims to provide an overview of recent efforts to develop PET and SPECT radiotracers for imaging of DNA damage repair proteins.

  19. Evaluation of image deblurring methods via a classification metric

    NASA Astrophysics Data System (ADS)

    Perrone, Daniele; Humphreys, David; Lamb, Robert A.; Favaro, Paolo

    2012-09-01

    The performance of single image deblurring algorithms is typically evaluated via a certain discrepancy measure between the reconstructed image and the ideal sharp image. The choice of metric, however, has been a source of debate and has also led to alternative metrics based on human visual perception. While fixed metrics may fail to capture some small but visible artifacts, perception-based metrics may favor reconstructions with artifacts that are visually pleasant. To overcome these limitations, we propose to assess the quality of reconstructed images via a task-driven metric. In this paper we consider object classification as the task and therefore use the rate of classification as the metric to measure deblurring performance. In our evaluation we use data with different types of blur in two cases: Optical Character Recognition (OCR), where the goal is to recognise characters in a black and white image, and object classification with no restrictions on pose, illumination and orientation. Finally, we show how off-the-shelf classification algorithms benefit from working with deblurred images.

  20. An Automated Image Processing System for Concrete Evaluation

    SciTech Connect

    Baumgart, C.W.; Cave, S.P.; Linder, K.E.

    1998-11-23

    AlliedSignal Federal Manufacturing & Technologies (FM&T) was asked to perform a proof-of-concept study for the Missouri Highway and Transportation Department (MHTD), Research Division, in June 1997. The goal of this proof-of-concept study was to ascertain if automated scanning and imaging techniques might be applied effectively to the problem of concrete evaluation. In the current evaluation process, a concrete sample core is manually scanned under a microscope. Voids (or air spaces) within the concrete are then detected visually by a human operator by incrementing the sample under the cross-hairs of a microscope and by counting the number of "pixels" which fall within a void. Automation of the scanning and image analysis processes is desired to improve the speed of the scanning process, to improve evaluation consistency, and to reduce operator fatigue. An initial, proof-of-concept image analysis approach was successfully developed and demonstrated using acquired black and white imagery of concrete samples. In this paper, the automated scanning and image capture system currently under development will be described and the image processing approach developed for the proof-of-concept study will be demonstrated. A development update and plans for future enhancements are also presented.

  1. Accuracy of physical examination, ultrasonography, and magnetic resonance imaging in predicting response to neo-adjuvant chemotherapy for breast cancer.

    PubMed

    Chen, Man; Zhan, Wei-Wei; Han, Bao-San; Fei, Xiao-Chun; Jin, Xiao-Long; Chai, Wei-Min; Wang, Deng-Bing; Shen, Kun-Wei; Wang, Wen-Ping

    2012-06-01

    Accurate evaluation of response following chemotherapy treatment is essential for surgical decision making in patients with breast cancer. Modalities that have been used to monitor response to neo-adjuvant chemotherapy (NAC) include physical examination (PE), ultrasound (US), and magnetic resonance imaging (MRI). The purpose of this study was to evaluate the accuracy of PE, US, and MRI in predicting the response to NAC in patients with breast cancer. According to the response evaluation criteria in solid tumors guidelines, the largest unidimensional measurement of the tumor diameter evaluated by PE, US, and MRI before and after NAC was classified into four grades, including clinical complete response, clinical partial response, clinical progressive disease, clinical stable disease, and compared with the final histopathological examination. Of the 64 patients who received NAC, the pathologic complete response (pCR) was shown in 13 of 64 patients (20%). The sensitivity of PE, US, and MRI in predicting the major pathologic response was 73%, 75%, and 80%, respectively, and the specificity was 45%, 50%, and 50% respectively. For predicting a pCR, the sensitivity of PE, US, and MRI was 46%, 46%, and 39%, respectively, and the specificity was 65%, 98%, and 92% respectively. Compared with final pathologic findings, all these three clinical and imaging modalities tended to obviously underestimate the pCR rate. A more appropriate, universal, and practical standard by clinical and imaging modalities in predicting the response to neo-adjuvant chemotherapy in vivo is essential.

  2. Radionuclide imaging in the evaluation of osteomyelitis and septic arthritis

    SciTech Connect

    Kim, E.E.; Haynie, T.P.; Podoloff, D.A.; Lowry, P.A.; Harle, T.S. )

    1989-01-01

    Despite controversy over its exact role, radionuclide imaging plays an important role in the evaluation of patients suspected of having osteomyelitis. The differentiation between osteomyelitis and cellulitis is best accomplished by using a three-phase technique using Tc-99m methylene diphosphonate (MDP). Frequently, it is necessary to obtain multiple projections and magnification views to adequately assess suspected areas. It is recommended that a Ga-67 or In-111 leukocyte scan be performed in those cases where osteomyelitis is strongly suspected clinically and the routine bone scan is equivocal or normal. Repeated bone scan after 48 to 72 h may demonstrate increased radioactivity in the case of early osteomyelitis with the initial photon-deficient lesion. In-111 leukocyte imaging is useful for the evaluation of suspected osteomyelitis complicating recent fracture or operation, but must be used in conjunction with clinical and radiographic correlation. The recognition of certain imaging patterns appears helpful to separate osteomyelitis from septic arthritis or cellulitis. 83 references.

  3. A comparison of image processing algorithms for thermal nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Zalameda, Joseph N.; Rajic, Nikolas; Winfree, William P.

    2003-04-01

    Thermography involves the application of heat to a structure and observation of surface temperature anomalies to reveal subsurface defects. Detection of subsurface defects can be greatly enhanced by the real time capture of a series of thermal images in time and the subsequent analysis of these images using various image processing algorithms. By applying image-processing algorithms, defects not readily observable can be detected and quantitatively characterized. The focus of this work is to investigate several of the numerous data reduction algorithms for thermal nondestructive evaluation by comparing results on a set of test samples. Some new types of data reduction algorithms have been recently developed with advantages such as noise reduction, file size compression, and material property measurements. By comparing various algorithms on factors such as computational speed, simplicity of use, robustness to noise, quantitative information, and optimum defect detection the most efficient algorithm may be chosen based on the user"s needs.

  4. Evaluation of hardware in a small-animal SPECT system using reconstructed images

    NASA Astrophysics Data System (ADS)

    Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Wilson, Donald W.; Barrett, Harrison H.

    2007-03-01

    Evaluation of imaging hardware represents a vital component of system design. In small-animal SPECT imaging, this evaluation has become increasingly diffcult with the emergence of multi-pinhole apertures and adaptive, or patient-specific, imaging. This paper will describe two methods for hardware evaluation using reconstructed images. The first method is a rapid technique incorporating a system-specific non-linear, three-dimensional point response. This point response is easily computed and offers qualitative insight into an aperture's resolution and artifact characteristics. The second method is an objective assessment of signal detection in lumpy backgrounds using the channelized Hotelling observer (CHO) with 3D Laguerre-Gauss and difference-of-Gaussian channels to calculate area under the receiver-operating characteristic curve (AUC). Previous work presented at this meeting described a unique, small-animal SPECT system (M 3R) capable of operating under a myriad of hardware configurations and ideally suited for image quality studies. Measured system matrices were collected for several hardware configurations of M 3R. The data used to implement these two methods was then generated by taking simulated objects through the measured system matrices. The results of these two methods comprise a combination of qualitative and quantitative analysis that is well-suited for hardware assessment.

  5. A Dynamic Image Quality Evaluation of Videofluoroscopy Images: Considerations for Telepractice Applications.

    PubMed

    Burns, Clare L; Keir, Benjamin; Ward, Elizabeth C; Hill, Anne J; Farrell, Anna; Phillips, Nick; Porter, Linda

    2015-08-01

    High-quality fluoroscopy images are required for accurate interpretation of videofluoroscopic swallow studies (VFSS) by speech pathologists and radiologists. Consequently, integral to developing any system to conduct VFSS remotely via telepractice is ensuring that the quality of the VFSS images transferred via the telepractice system is optimized. This study evaluates the extent of change observed in image quality when videofluoroscopic images are transmitted from a digital fluoroscopy system to (a) current clinical equipment (KayPentax Digital Swallowing Workstation, and b) four different telepractice system configurations. The telepractice system configurations consisted of either a local C20 or C60 Cisco TelePresence System (codec unit) connected to the digital fluoroscopy system and linked to a second remote C20 or C60 Cisco TelePresence System via a network running at speeds of either 2, 4 or 6 megabits per second (Mbit/s). Image quality was tested using the NEMA XR 21 Phantom, and results demonstrated some loss in spatial resolution, low contrast detectability and temporal resolution for all transferred images when compared to the fluoroscopy source. When using higher capacity codec units and/or the highest bandwidths to support data transmission, image quality transmitted through the telepractice system was found to be comparable if not better than the current clinical system. This study confirms that telepractice systems can be designed to support fluoroscopy image transfer and highlights important considerations when developing telepractice systems for VFSS analysis to ensure high-quality radiological image reproduction.

  6. Evaluation of Skybox Video and Still Image products

    NASA Astrophysics Data System (ADS)

    d'Angelo, P.; Kuschk, G.; Reinartz, P.

    2014-11-01

    The SkySat-1 satellite lauched by Skybox Imaging on November 21 in 2013 opens a new chapter in civilian earth observation as it is the first civilian satellite to image a target in high definition panchromatic video for up to 90 seconds. The small satellite with a mass of 100 kg carries a telescope with 3 frame sensors. Two products are available: Panchromatic video with a resolution of around 1 meter and a frame size of 2560 × 1080 pixels at 30 frames per second. Additionally, the satellite can collect still imagery with a swath of 8 km in the panchromatic band, and multispectral images with 4 bands. Using super-resolution techniques, sub-meter accuracy is reached for the still imagery. The paper provides an overview of the satellite design and imaging products. The still imagery product consists of 3 stripes of frame images with a footprint of approximately 2.6 × 1.1 km. Using bundle block adjustment, the frames are registered, and their accuracy is evaluated. Image quality of the panchromatic, multispectral and pansharpened products are evaluated. The video product used in this evaluation consists of a 60 second gazing acquisition of Las Vegas. A DSM is generated by dense stereo matching. Multiple techniques such as pairwise matching or multi image matching are used and compared. As no ground truth height reference model is availble to the authors, comparisons on flat surface and compare differently matched DSMs are performed. Additionally, visual inspection of DSM and DSM profiles show a detailed reconstruction of small features and large skyscrapers.

  7. Politics in evaluation: Politically responsive evaluation in high stakes environments.

    PubMed

    Azzam, Tarek; Levine, Bret

    2015-12-01

    The role of politics has often been discussed in evaluation theory and practice. The political influence of the situation can have major effects on the evaluation design, approach and methods. Politics also has the potential to influence the decisions made from the evaluation findings. The current study focuses on the influence of the political context on stakeholder decision making. Utilizing a simulation scenario, this study compares stakeholder decision making in high and low stakes evaluation contexts. Findings suggest that high stakes political environments are more likely than low stakes environments to lead to reduced reliance on technically appropriate measures and increased dependence on measures better reflect the broader political environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Image processing system performance prediction and product quality evaluation

    NASA Technical Reports Server (NTRS)

    Stein, E. K.; Hammill, H. B. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

  9. Evaluation of Infrared Images by Using a Human Thermal Model

    DTIC Science & Technology

    2001-10-25

    thermal environmental history have been recorded. In this case, the thermal environmental history could be estimated from the behavior of a subject... environmental history and physiological condition history. An advantage of the evaluation of IR images using the thermal model is to provide

  10. Evaluation of stereoscopic 3D displays for image analysis tasks

    NASA Astrophysics Data System (ADS)

    Peinsipp-Byma, E.; Rehfeld, N.; Eck, R.

    2009-02-01

    In many application domains the analysis of aerial or satellite images plays an important role. The use of stereoscopic display technologies can enhance the image analyst's ability to detect or to identify certain objects of interest, which results in a higher performance. Changing image acquisition from analog to digital techniques entailed the change of stereoscopic visualisation techniques. Recently different kinds of digital stereoscopic display techniques with affordable prices have appeared on the market. At Fraunhofer IITB usability tests were carried out to find out (1) with which kind of these commercially available stereoscopic display techniques image analysts achieve the best performance and (2) which of these techniques achieve a high acceptance. First, image analysts were interviewed to define typical image analysis tasks which were expected to be solved with a higher performance using stereoscopic display techniques. Next, observer experiments were carried out whereby image analysts had to solve defined tasks with different visualization techniques. Based on the experimental results (performance parameters and qualitative subjective evaluations of the used display techniques) two of the examined stereoscopic display technologies were found to be very good and appropriate.

  11. Evaluation of the lateral pterygoid muscle using magnetic resonance imaging

    PubMed Central

    D'Ippolito, SM; Borri Wolosker, AM; D'Ippolito, G; Herbert de Souza, B; Fenyo-Pereira, M

    2010-01-01

    Objectives The aims of this study were to evaluate the visibility of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) images obtained by MRI, using different projections and to compare image findings with clinical symptoms of patients with and without temporomandibular disorders (TMD). Methods In this study, LPM images of 50 participants with and without TMDs were investigated by MRI. The images of the LPM in different projections of 100 TMJs from 35 participants (70 TMJs) with and 15 participants (30 TMJs) without clinical signs and symptoms of TMD were visible and analysed. Results The oblique sagittal and axial images of the TMJ clearly showed the LPM. Hypertrophy (1.45%), atrophy (2.85%) and contracture (2.85%) were the abnormalities found in the LPM. TMD signs, such as hypermobility (11.4%), hypomobility (12.9%) and disc displacement (20.0%), could be seen in TMJ images. Related clinical symptoms, such as pain (71.4%), articular sounds (30.4%), bruxism (25.7%) and headache (22.9%), were observed. Conclusions Patients with TMD can present with alterations in the LPM thickness. Patients without TMD also showed alterations, such as atrophy and contracture, in TMJ images. Recognition of alterations in the LPM will improve our understanding of clinical symptoms and pathophysiology of TMD, and may lead to a more specific diagnosis of these disorders. PMID:21062943

  12. Evaluating method for the double image phenomenon of LED lighting

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Hong; Kuo, Chao-Hui; Hung, Min-Wei; Huang, Kuo-Cheng

    In recent years, the overriding advantages long life, high efficiency, small size and short reaction time have made LED become a viable alternative to conventional light sources. LED lighting sources are usually composed of several individual LED cells which must be mounted on a panel as a lighting module. Being composed of several individual LED cells, the LED sources will cause the double image phenomenon. The double image phenomenon is more obvious when the LED sources are more closer, such as LED table lamp, and limits the applications of LED sources. By using a proper secondary optical lens, the double image phenomenon can be reduced. In this research, an evaluating method based on image processing is developed for the double image phenomenon of a LED sources. By analyzing the gray-scale of the grabbed image which is obtained by putting a rob under a LED source, an index of double image can be established and be a criterion to judge different LED sources. Furthermore, a series of LED lighting simulations are shown in this paper and several type of secondary optical lens are compared and discussed in this paper as well.

  13. Evaluation of chirp reversal power modulation sequence for contrast agent imaging.

    PubMed

    Novell, A; Sennoga, C A; Escoffre, J M; Chaline, J; Bouakaz, A

    2014-09-07

    Over the last decade, significant research effort has been focused on the use of chirp for contrast agent imaging because chirps are known to significantly increase imaging contrast-to-noise ratio (CNR). New imaging schemes, such as chirp reversal (CR), have been developed to improve contrast detection by increasing non-linear microbubble responses. In this study we evaluated the contrast enhancement efficiency of various chirped imaging sequences in combination with well-established imaging schemes such as power modulation (PM) and pulse inversion (PI). The imaging schemes tested were implemented on a fully programmable open scanner and evaluated by ultrasonically scanning (excitation frequency of 2.5 MHz; amplitude of 350 kPa) a tissue-mimicking flow phantom comprising a 4 mm diameter tube through which aqueous dispersions (dilution fraction of 1/2000) of the commercial ultrasound contrast agent, SonoVue(®) were continuously circulated. The recovery of non-linear microbubble responses after chirp compression requires the development and the optimization of a specific filter. A compression filter was therefore designed and used to compress and extract several non-linear components from the received microbubble responses. The results showed that using chirps increased the image CNR by approximately 10 dB, as compared to conventional Gaussian apodized sine burst excitation but degraded the axial resolution by a factor of 1.4, at -3 dB. We demonstrated that the highest CNR and contrast-to-noise ratio (CTR) were achievable when CR was combined with PM as compared to other imaging schemes such as PI.

  14. PET-CT in Staging, Response Evaluation, and Surveillance of Lymphoma.

    PubMed

    Thanarajasingam, Gita; Bennani-Baiti, Nabila; Thompson, Carrie A

    2016-05-01

    Lymphoma represents a broad spectrum of diseases with diverse biology, clinical behavior, and imaging features. Functional imaging with 18-F-fluorodeoxyglucose (FDG)-positron emission tomography combined with computed tomography (PET-CT) is widely recognized as the most sensitive and specific imaging modality for patients with lymphoma and is used as part of staging, response evaluation, and surveillance in patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). Recent efforts at standardizing the conduct and consensus interpretation of PET-CT have facilitated its use in patients on clinical studies and beyond. The role of PET-CT has been affirmed in some clinical situations, such as staging and end-of-treatment evaluation in Hodgkin lymphoma and diffuse large B cell lymphoma (DLBCL), and in the evaluation of aggressive transformation of an indolent lymphoma. However, the role of functional imaging in other histologies and clinical settings is not as clear given the higher rate of false positive results and the costs inherent to PET-CT. There is little evidence to suggest its utility or impact on outcome in most indolent lymphomas, or in the setting of post-treatment surveillance. In addition, there remains controversy about the value of PET-CT in early response assessment during active therapy, particularly in DLBCL. This review will evaluate the evidence surrounding the role of PET-CT in staging, response evaluation and surveillance of Hodgkin and non-Hodgkin lymphoma.

  15. Evaluation of Kinect 3D Sensor for Healthcare Imaging.

    PubMed

    Pöhlmann, Stefanie T L; Harkness, Elaine F; Taylor, Christopher J; Astley, Susan M

    2016-01-01

    Microsoft Kinect is a three-dimensional (3D) sensor originally designed for gaming that has received growing interest as a cost-effective and safe device for healthcare imaging. Recent applications of Kinect in health monitoring, screening, rehabilitation, assistance systems, and intervention support are reviewed here. The suitability of available technologies for healthcare imaging applications is assessed. The performance of Kinect I, based on structured light technology, is compared with that of the more recent Kinect II, which uses time-of-flight measurement, under conditions relevant to healthcare applications. The accuracy, precision, and resolution of 3D images generated with Kinect I and Kinect II are evaluated using flat cardboard models representing different skin colors (pale, medium, and dark) at distances ranging from 0.5 to 1.2 m and measurement angles of up to 75°. Both sensors demonstrated high accuracy (majority of measurements <2 mm) and precision (mean point to plane error <2 mm) at an average resolution of at least 390 points per cm(2). Kinect I is capable of imaging at shorter measurement distances, but Kinect II enables structures angled at over 60° to be evaluated. Kinect II showed significantly higher precision and Kinect I showed significantly higher resolution (both p < 0.001). The choice of object color can influence measurement range and precision. Although Kinect is not a medical imaging device, both sensor generations show performance adequate for a range of healthcare imaging applications. Kinect I is more appropriate for short-range imaging and Kinect II is more appropriate for imaging highly curved surfaces such as the face or breast.

  16. An automated deformable image registration evaluation of confidence tool

    NASA Astrophysics Data System (ADS)

    Kirby, Neil; Chen, Josephine; Kim, Hojin; Morin, Olivier; Nie, Ke; Pouliot, Jean

    2016-04-01

    Deformable image registration (DIR) is a powerful tool for radiation oncology, but it can produce errors. Beyond this, DIR accuracy is not a fixed quantity and varies on a case-by-case basis. The purpose of this study is to explore the possibility of an automated program to create a patient- and voxel-specific evaluation of DIR accuracy. AUTODIRECT is a software tool that was developed to perform this evaluation for the application of a clinical DIR algorithm to a set of patient images. In brief, AUTODIRECT uses algorithms to generate deformations and applies them to these images (along with processing) to generate sets of test images, with known deformations that are similar to the actual ones and with realistic noise properties. The clinical DIR algorithm is applied to these test image sets (currently 4). From these tests, AUTODIRECT generates spatial and dose uncertainty estimates for each image voxel based on a Student’s t distribution. In this study, four commercially available DIR algorithms were used to deform a dose distribution associated with a virtual pelvic phantom image set, and AUTODIRECT was used to generate dose uncertainty estimates for each deformation. The virtual phantom image set has a known ground-truth deformation, so the true dose-warping errors of the DIR algorithms were also known. AUTODIRECT predicted error patterns that closely matched the actual error spatial distribution. On average AUTODIRECT overestimated the magnitude of the dose errors, but tuning the AUTODIRECT algorithms should improve agreement. This proof-of-principle test demonstrates the potential for the AUTODIRECT algorithm as an empirical method to predict DIR errors.

  17. Hemodynamic Response Imaging: A Potential Tool for the Assessment of Angiogenesis in Brain Tumors

    PubMed Central

    Ben Ami, Haim; Aizenstein, Orna; Blumenthal, Deborah T.; Bokstein, Felix; Corn, Benjamin W.; Ram, Zvi; Kanner, Avraham A.; Lifschitz-Mercer, Biatris; Solar, Irit; Kolatt, Tsafrir; Palmon, Mika; Edrei, Yifat; Abramovitch, Rinat

    2012-01-01

    Blood oxygenation level dependence (BOLD) imaging under either hypercapnia or hyperoxia has been used to study neuronal activation and for assessment of various brain pathologies. We evaluated the benefit of a combined protocol of BOLD imaging during both hyperoxic and hypercapnic challenges (termed hemodynamic response imaging (HRI)). Nineteen healthy controls and seven patients with primary brain tumors were included: six with glioblastoma (two newly diagnosed and four with recurrent tumors) and one with atypical-meningioma. Maps of percent signal intensity changes (ΔS) during hyperoxia (carbogen; 95%O2+5%CO2) and hypercapnia (95%air+5%CO2) challenges and vascular reactivity mismatch maps (VRM; voxels that responded to carbogen with reduced/absent response to CO2) were calculated. VRM values were measured in white matter (WM) and gray matter (GM) areas of healthy subjects and used as threshold values in patients. Significantly higher response to carbogen was detected in healthy subjects, compared to hypercapnia, with a GM/WM ratio of 3.8 during both challenges. In patients with newly diagnosed/treatment-naive tumors (n = 3), increased response to carbogen was detected with substantially increased VRM response (compared to threshold values) within and around the tumors. In patients with recurrent tumors, reduced/absent response during both challenges was demonstrated. An additional finding in 2 of 4 patients with recurrent glioblastoma was a negative response during carbogen, distant from tumor location, which may indicate steal effect. In conclusion, the HRI method enables the assessment of blood vessel functionality and reactivity. Reference values from healthy subjects are presented and preliminary results demonstrate the potential of this method to complement perfusion imaging for the detection and follow up of angiogenesis in patients with brain tumors. PMID:23209575

  18. Physical exercise and brain responses to images of high-calorie food.

    PubMed

    Killgore, William D S; Kipman, Maia; Schwab, Zachary J; Tkachenko, Olga; Preer, Lily; Gogel, Hannah; Bark, John S; Mundy, Elizabeth A; Olson, Elizabeth A; Weber, Mareen

    2013-12-04

    Physical exercise has many health benefits, including improved cardiovascular fitness, lean muscle development, increased metabolism, and weight loss, as well as positive effects on brain functioning and cognition. Recent evidence suggests that regular physical exercise may also affect the responsiveness of reward regions of the brain to food stimuli. We examined whether the total number of minutes of self-reported weekly physical exercise was related to the responsiveness of appetite and food reward-related brain regions to visual presentations of high-calorie and low-calorie food images during functional MRI. Second, we examined whether such responses would correlate with self-reported food preferences. While undergoing scanning, 37 healthy adults (22 men) viewed images of high-calorie and low-calorie foods and provided desirability ratings for each food image. The correlation between exercise minutes per week and brain responses to the primary condition contrast (high-calorie>low-calorie) was evaluated within the amygdala, insula, and medial orbitofrontal cortex, brain regions previously implicated in responses to food images. Higher levels of exercise were significantly correlated with lower responsiveness within the medial orbitofrontal cortex and left insula to high-calorie foods. Furthermore, activation of these regions was positively correlated with preference ratings for high-calorie foods, particularly those with a savory flavor. These findings suggest that physical exercise may be associated with reduced activation in food-responsive reward regions, which are in turn associated with reduced preferences for unhealthy high-calorie foods. Physical exercise may confer secondary health benefits beyond its primary effects on cardiovascular fitness and energy expenditure.

  19. Restriction spectrum imaging predicts response to bevacizumab in patients with high-grade glioma.

    PubMed

    McDonald, Carrie R; Delfanti, Rachel L; Krishnan, Anitha P; Leyden, Kelly M; Hattangadi-Gluth, Jona A; Seibert, Tyler M; Karunamuni, Roshan; Elbe, Pia; Kuperman, Joshua M; Bartsch, Hauke; Piccioni, David E; White, Nathan S; Dale, Anders M; Farid, Nikdokht

    2016-11-01

    Diffusion-weighted imaging has shown initial promise for evaluating response to bevacizumab in patients with high-grade glioma (HGG). However, it is well recognized that the apparent diffusion coefficient (ADC) is influenced by bevacizumab-induced reductions in edema, which may limit its prognostic value. We demonstrate that an advanced diffusion-weighted imaging technique, restriction spectrum imaging (RSI), improves the evaluation of response to bevacizumab because unlike ADC, RSI is not affected by resolution of edema. RSI and ADC maps were analyzed for 40 patients with HGG prior to and following initiation of bevacizumab. Volumes of interest were drawn for regions of contrast enhancement (CE) and fluid attenuated inversion recovery (FLAIR) hyperintensity and histogram percentiles within volumes of interest were calculated for ADC 10th percentile (ADC-CE10%, ADC-FLAIR10%) and for RSI 90th percentile (RSI-CE90%, RSI-FLAIR90%). Cox proportional hazard models were used to evaluate the relationship between imaging parameters, progression-free survival (PFS), and overall survival (OS). An increase in RSI-FLAIR90% following bevacizumab was the strongest predictor of poor PFS (P= .016) and OS (P= .004), whereas decreases in ADC-FLAIR10% showed a weaker association with OS only (P= .041). Within the CE region, increases in RSI-CE90% alone were associated with poorer OS. Correlational analysis revealed that decreases in FLAIR volume were associated with decreases in ADC-FLAIR10%, but not with changes in RSI-FLAIR90%. RSI is less influenced by changes in edema, conferring an advantage of RSI over ADC for evaluating response to anti-angiogenic therapy in patients with HGG. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Evaluation of nucleus segmentation in digital pathology images through large scale image synthesis

    NASA Astrophysics Data System (ADS)

    Zhou, Naiyun; Yu, Xiaxia; Zhao, Tianhao; Wen, Si; Wang, Fusheng; Zhu, Wei; Kurc, Tahsin; Tannenbaum, Allen; Saltz, Joel; Gao, Yi

    2017-03-01

    Digital histopathology images with more than 1 Gigapixel are drawing more and more attention in clinical, biomedical research, and computer vision fields. Among the multiple observable features spanning multiple scales in the pathology images, the nuclear morphology is one of the central criteria for diagnosis and grading. As a result it is also the mostly studied target in image computing. Large amount of research papers have devoted to the problem of extracting nuclei from digital pathology images, which is the foundation of any further correlation study. However, the validation and evaluation of nucleus extraction have yet been formulated rigorously and systematically. Some researches report a human verified segmentation with thousands of nuclei, whereas a single whole slide image may contain up to million. The main obstacle lies in the difficulty of obtaining such a large number of validated nuclei, which is essentially an impossible task for pathologist. We propose a systematic validation and evaluation approach based on large scale image synthesis. This could facilitate a more quantitatively validated study for current and future histopathology image analysis field.

  1. Imaging quality evaluation method of pixel coupled electro-optical imaging system

    NASA Astrophysics Data System (ADS)

    He, Xu; Yuan, Li; Jin, Chunqi; Zhang, Xiaohui

    2017-09-01

    With advancements in high-resolution imaging optical fiber bundle fabrication technology, traditional photoelectric imaging system have become ;flexible; with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the coupling discrete sampling effect of fiber-optic image bundles and charge-coupled device (CCD) pixels. This limitation substantially complicates the design, optimization, assembly, and evaluation image quality of the coupled discrete sampling imaging system. Based on the transfer process of grayscale cosine distribution optical signal in the fiber-optic image bundle and CCD, a mathematical model of coupled modulation transfer function (coupled-MTF) is established. This model can be used as a basis for following studies on the convergence and periodically oscillating characteristics of the function. We also propose the concept of the average coupled-MTF, which is consistent with the definition of traditional MTF. Based on this concept, the relationships among core distance, core layer radius, and average coupled-MTF are investigated.

  2. Measurement and evaluation techniques for automated demand response demonstration

    SciTech Connect

    Motegi, Naoya; Piette, Mary Ann; Watson, David S.; Sezgen, Osman; ten Hope, Laurie

    2004-08-01

    The recent electricity crisis in California and elsewhere has prompted new research to evaluate demand response strategies in large facilities. This paper describes an evaluation of fully automated demand response technologies (Auto-DR) in five large facilities. Auto-DR does not involve human intervention, but is initiated at a facility through receipt of an external communications signal. This paper summarizes the measurement and evaluation of the performance of demand response technologies and strategies in five large facilities. All the sites have data trending systems such as energy management and control systems (EMCS) and/or energy information systems (EIS). Additional sub-metering was applied where necessary to evaluate the facility's demand response performance. This paper reviews the control responses during the test period, and analyzes demand savings achieved at each site. Occupant comfort issues are investigated where data are available. This paper discusses methods to estimate demand savings and results from demand response strategies at five large facilities.

  3. Performance evaluation of image processing algorithms in digital mammography

    NASA Astrophysics Data System (ADS)

    Zanca, Federica; Van Ongeval, Chantal; Jacobs, Jurgen; Pauwels, Herman; Marchal, Guy; Bosmans, Hilde

    2008-03-01

    The purpose of the study is to evaluate the performance of different image processing algorithms in terms of representation of microcalcification clusters in digital mammograms. Clusters were simulated in clinical raw ("for processing") images. The entire dataset of images consisted of 200 normal mammograms, selected out of our clinical routine cases and acquired with a Siemens Novation DR system. In 100 of the normal images a total of 142 clusters were simulated; the remaining 100 normal mammograms served as true negative input cases. Both abnormal and normal images were processed with 5 commercially available processing algorithms: Siemens OpView1 and Siemens OpView2, Agfa Musica1, Sectra Mamea AB Sigmoid and IMS Raffaello Mammo 1.2. Five observers were asked to locate and score the cluster(s) in each image, by means of dedicated software tool. Observer performance was assessed using the JAFROC Figure of Merit. FROC curves, fitted using the IDCA method, have also been calculated. JAFROC analysis revealed significant differences among the image processing algorithms in the detection of microcalcifications clusters (p=0.0000369). Calculated average Figures of Merit are: 0.758 for Siemens OpView2, 0.747 for IMS Processing 1.2, 0.736 for Agfa Musica1 processing, 0.706 for Sectra Mamea AB Sigmoid processing and 0.703 for Siemens OpView1. This study is a first step towards a quantitative assessment of image processing in terms of cluster detection in clinical mammograms. Although we showed a significant difference among the image processing algorithms, this method does not on its own allow for a global performance ranking of the investigated algorithms.

  4. Evaluating EUV mask pattern imaging with two EUV microscopes

    SciTech Connect

    Goldberg, Kenneth A.; Takase, Kei; Naulleau, Patrick P.; Han, Hakseung; Barty, Anton; Kinoshita, Hiroo; Hamamoto, Kazuhiro

    2008-02-26

    Aerial image measurement plays a key role in the development of patterned reticles for each generation of lithography. Studying the field transmitted (reflected) from EUV masks provides detailed information about potential disruptions caused by mask defects, and the performance of defect repair strategies, without the complications of photoresist imaging. Furthermore, by measuring the continuously varying intensity distribution instead of a thresholded, binary resist image, aerial image measurement can be used as feedback to improve mask and lithography system modeling methods. Interest in EUV, at-wavelength, aerial image measurement lead to the creation of several research tools worldwide. These tools are used in advanced mask development work, and in the evaluation of the need for commercial at-wavelength inspection tools. They describe performance measurements of two such tools, inspecting the same EUV mask in a series of benchmarking tests that includes brightfield and darkfield patterns. One tool is the SEMATECH Berkeley Actinic Inspection Tool (AIT) operating on a bending magnet beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. The AIT features an EUV Fresnel zoneplate microscope that emulates the numerical aperture of a 0.25-NA stepper, and projects the aerial image directly onto a CCD camera, with 700x magnification. The second tool is an EUV microscope (EUVM) operating at the NewSUBARU synchrotron in Hyogo, Japan. The NewSUBARU tool projects the aerial image using a reflective, 30x Schwarzschild objective lens, followed by a 10-200x x-ray zooming tube. The illumination conditions and the imaging etendue are different for the two tools. The benchmarking measurements were used to determine many imaging and performance properties of the tools, including resolution, modulation transfer function (MTF), aberration magnitude, aberration field-dependence (including focal-plane tilt), illumination uniformity, line-edge roughness, and flare

  5. Toward objective and quantitative evaluation of imaging systems using images of phantoms.

    PubMed

    Gagne, Robert M; Gallas, Brandon D; Myers, Kyle J

    2006-01-01

    The use of imaging phantoms is a common method of evaluating image quality in the clinical setting. These evaluations rely on a subjective decision by a human observer with respect to the faintest detectable signal(s) in the image. Because of the variable and subjective nature of the human-observer scores, the evaluations manifest a lack of precision and a potential for bias. The advent of digital imaging systems with their inherent digital data provides the opportunity to use techniques that do not rely on human-observer decisions and thresholds. Using the digital data, signal-detection theory (SDT) provides the basis for more objective and quantitative evaluations which are independent of a human-observer decision threshold. In a SDT framework, the evaluation of imaging phantoms represents a "signal-known-exactly/background-known-exactly" ("SKE/ BKE") detection task. In this study, we compute the performance of prewhitening and nonprewhitening model observers in terms of the observer signal-to-noise ratio (SNR) for these "SK E/BKE" tasks. We apply the evaluation methods to a number of imaging systems. For example, we use data from a laboratory implementation of digital radiography and from a full-field digital mammography system in a clinical setting. In addition, we make a comparison of our methods to human-observer scoring of a set of digital images of the CDMAM phantom available from the internet (EUREF-European Reference Organization). In the latter case, we show a significant increase in the precision of the quantitative methods versus the variability in the scores from human observers on the same set of images. As regards bias, the performance of a model observer estimated from a finite data set is known to be biased. In this study, we minimize the bias and estimate the variance of the observer SNR using statistical resampling techniques, namely, "bootstrapping" and "shuffling" of the data sets. Our methods provide objective and quantitative evaluation of

  6. Comparison of retinal image evaluation techniques in novice clinicians

    PubMed Central

    Putnam, Christopher M.; Permann, Alex; Bassi, Carl J.

    2015-01-01

    Abstract. Retinal fundus evaluation is learned through experience and training. This study aimed to determine the image presentation characteristics and the accompanying evaluation techniques, which led to the most accurate and efficient retinal pathology detection method. Phase I included 25 novice clinicians asked to evaluate 14 different pathologies using spatial versus temporal image presentations. Phase II included 25 different novice clinicians asked to evaluate five different simulated pathologies at three different pixel sizes presented in both spatial and temporal image presentations. Accuracy and speed of recognition were evaluated between the spatial and temporal presentations of the same simulated pathology. In phase l, subjects were significantly faster at simulated pathology detection using a temporal presentation with a 95% accuracy rate versus a spatial presentation with a 79% accuracy rate. In phase II, subjects demonstrated significant differences in speed of detection using the temporal technique at all 3 pixel number sizes with the greatest difference in detection times shown at the smallest retinal defects. Accuracy and speed of recognition in simulated pathology assessment were improved in a temporal presentation and the greatest improvements were demonstrated at the smallest pixel numbers. PMID:26158113

  7. Computerized geometric evaluation of angio- and echocardiographic images.

    PubMed

    Onnasch, D G

    1985-08-01

    Since the first comprehensive computerized videometric systems for quantitative assessment of the dynamic morphology and function of the heart have been developed, angiocardiographic image generation and computer aided evaluation have improved considerably. As a second method for morphological imaging echocardiography is also established in cardiology, so that videometry branched off into angio- and echocardiometry. In this paper, the common aspects of both methods are discussed concerning manual outlining and computerized contour representation, additional storage of anatomical landmarks labelled by digits and letters, and list-directed automated evaluation of data. It allows standard graphical documentations including comparisons of global volumetric and functional results for individual patients as well as versatile research orientated evaluations of oblique semi-axes, sectorial areas, wall thicknesses, shape parameters, spatial orientation and derived global and regional functional parameters for patient groups. As an example wall thickness measured from echographic long and short axis views and from angiographic projections are compared.

  8. Application of remote sensing image interpretation in seismic safety evaluation

    NASA Astrophysics Data System (ADS)

    Li, Feng; Wei, Wen-xia; Wang, Gang

    2005-10-01

    As one of essential design gist in important engineering projects, the seismic safety evaluation on choosing engineering site has been applied widely. Using remote sensing images, the analysis to regional seismotectonic environment can bring macroscopic, integrative, dynamic and high efficiency information, so the application of remote sensing technology in seismic safety evaluation of engineering site has fine prospect and will bring great benefit. In this paper, based on remote sensing interpretation to Landsat7 ETM images, also using GIS and field geological investigations, as a case study in Qingdao City, we analyze the physiognomy environment, new tectonic movement, faults activities, and the distributing of deleterious geological objects around the site. Then we find this method can provide good basic geological information for seismic safety evaluation.

  9. Neural response imaging (NRI) cochlear mapping: prospects for clinical application.

    PubMed

    Arnold, L; Lindsey, P; Hacking, C; Boyle, P

    2007-12-01

    The objective of the study was to investigate the potential for clinical application of neural response imaging (NRI) cochlear mapping. Cochlear mapping was performed at each fitting session up to at least six months following initial fitting. Stimulation was delivered to one electrode site. NRI was recorded from each of the remaining sites. The procedure was repeated for apical, medial and basal stimulation sites, stimulating at subjective threshold and most comfortable levels. Responses were obtained in five out of six subjects and are discussed in terms of: reproducibility, quality, changes over time. Cochlear mapping provided repeatable data that gave interesting insights into the implanted cochlea. Further work is required to determine whether this approach could contribute to programme optimisation.

  10. Evaluation of segmentation using lung nodule phantom CT images

    NASA Astrophysics Data System (ADS)

    Judy, Philip F.; Jacobson, Francine L.

    2001-07-01

    Segmentation of chest CT images has several purposes. In lung-cancer screening programs, for nodules below 5mm, growth measured from sequential CT scans is the primary indication of malignancy. Automatic segmentation procedures have been used as a means to insure a reliable measurement of lung nodule size. A lung nodule phantom was developed to evaluate the validity and reliability of size measurements using CT images. Thirty acrylic spheres and cubes (2-8 mm) were placed in a 15cm diameter disk of uniform-material that simulated the lung. To demonstrate the use of the phantom, it was scanned using out hospital's lung-cancer screening protocol. A simple, yet objective threshold technique was used to segment all of the images in which the objects were visible. All the pixels above a common threshold (the mean of the lung material and the acrylic CT numbers) were considered within the nodule. The relative bias did not depend on the shape of the objects and ranged from -18% for the 2 mm objects to -2.5% for 8-mm objects. DICOM image files of the phantom are available for investigators with an interest in using the images to evaluate and compare segmentation procedures.

  11. Metabolic Imaging to Assess Treatment Response to Cytotoxic and Cytostatic Agents

    PubMed Central

    Serkova, Natalie J.; Eckhardt, S. Gail

    2016-01-01

    For several decades, cytotoxic chemotherapeutic agents were considered the basis of anticancer treatment for patients with metastatic tumors. A decrease in tumor burden, assessed by volumetric computed tomography and magnetic resonance imaging, according to the response evaluation criteria in solid tumors (RECIST), was considered as a radiological response to cytotoxic chemotherapies. In addition to RECIST-based dimensional measurements, a metabolic response to cytotoxic drugs can be assessed by positron emission tomography (PET) using 18F-fluoro-thymidine (FLT) as a radioactive tracer for drug-disrupted DNA synthesis. The decreased 18FLT-PET uptake is often seen concurrently with increased apparent diffusion coefficients by diffusion-weighted imaging due to chemotherapy-induced changes in tumor cellularity. Recently, the discovery of molecular origins of tumorogenesis led to the introduction of novel signal transduction inhibitors (STIs). STIs are targeted cytostatic agents; their effect is based on a specific biological inhibition with no immediate cell death. As such, tumor size is not anymore a sensitive end point for a treatment response to STIs; novel physiological imaging end points are desirable. For receptor tyrosine kinase inhibitors as well as modulators of the downstream signaling pathways, an almost immediate inhibition in glycolytic activity (the Warburg effect) and phospholipid turnover (the Kennedy pathway) has been seen by metabolic imaging in the first 24 h of treatment. The quantitative imaging end points by magnetic resonance spectroscopy and metabolic PET (including 18F-fluoro-deoxy-glucose, FDG, and total choline) provide an early treatment response to targeted STIs, before a reduction in tumor burden can be seen. PMID:27471678

  12. Development and validation of experimental models for hyperemic thermal response using IR imaging

    NASA Astrophysics Data System (ADS)

    Moreno, Eulalia; Hsieh, Sheng-Jen; Palomares, Benjamin Giron

    2012-06-01

    A common method for diagnosing heart health condition is to analyze blood flow rate and temperature behaviors after arterial occlusion. However, multiple factors besides heart condition could affect these behaviors. The objective of this research was to identify other factors that affect blood flow and thermal response after arterial occlusion, evaluate a mathematical model to determine thermal response after arterial occlusion, and develop an experimental model for thermal response after arterial occlusion. Twenty-eight experiments were conducted with 14 subjects to determine blood and thermal responses by using plethysmography and infrared imaging after applying arterial occlusion. Possible factors affecting blood flow and thermal responses that were investigated were: Initial finger temperature, blood pressure, body temperature, gender, and age. After determining the correlation coefficient among the mentioned factors and blood flow and thermal responses after occlusion, it was determined that only initial finger temperature and blood pressure show a strong effect. A mathematical model accounting only for the convective thermal effects, but not thermal conduction effects, was developed and tested, but was found to be insufficiently accurate in describing the thermal response by means of blood flow parameters for all of the subjects tested (error>90%). A linear regression model was then developed to relate blood flow to thermal response using two thirds of the experimental data, and was tested using one third of the data. The linear regression model was found to predict thermal response by means of blood flow response with an error rate of less than 50%.

  13. Imaging Bone Metastases in Breast Cancer: Staging and Response Assessment.

    PubMed

    Cook, Gary J R; Azad, Gurdip K; Goh, Vicky

    2016-02-01

    Bone metastases are common in patients with advanced breast cancer. Given the significant associated morbidity, the introduction of new, effective systemic therapies, and the improvement in survival time, early detection and response assessment of skeletal metastases have become even more important. Although planar bone scanning has recognized limitations, in particular, poor specificity in staging and response assessment, it continues to be the main method in current clinical practice for staging of the skeleton in patients at risk of bone metastases. However, the accuracy of bone scanning can be improved with the addition of SPECT/CT. There have been reported improvements in sensitivity and specificity for staging of the skeleton with either bone-specific PET/CT tracers, such as (18)F-NaF, or tumor-specific tracers, such as (18)F-FDG, although these methods are less widely available and more costly. There is a paucity of data on the use of (18)F-NaF PET/CT for response assessment in breast cancer, but there is increasing evidence that (18)F-FDG PET/CT may improve on current methods in this regard. At the same time, interest and experience in using whole-body morphologic MRI augmented with diffusion-weighted imaging for both staging and response assessment in the skeleton have been increasing. However, data on comparisons of these methods with PET methods to determine the best technique for current clinical practice or for clinical trials are insufficient. There are early data supporting the use (18)F-FDG PET/MRI to assess malignant disease in the skeleton, with the possibility of taking advantage of the synergies offered by combining morphologic, physiologic, and metabolic imaging.

  14. Study of fish response using particle image velocimetry and high-speed, high-resolution imaging

    SciTech Connect

    Deng, Z.; Richmond, M. C.; Mueller, R. P.; Gruensch, G. R.

    2004-10-01

    Fish swimming has fascinated both engineers and fish biologists for decades. Digital particle image velocimetry (DPIV) and high-speed, high-resolution digital imaging are recently developed analysis tools that can help engineers and biologists better understand how fish respond to turbulent environments. This report details studies to evaluate DPIV. The studies included a review of existing literature on DPIV, preliminary studies to test the feasibility of using DPIV conducted at our Flow Biology Laboratory in Richland, Washington September through December 2003, and applications of high-speed, high-resolution digital imaging with advanced motion analysis to investigations of fish injury mechanisms in turbulent shear flows and bead trajectories in laboratory physical models. Several conclusions were drawn based on these studies, which are summarized as recommendations for proposed research at the end of this report.

  15. Prospective Evaluation of Multimodal Optical Imaging with Automated Image Analysis to Detect Oral Neoplasia In Vivo.

    PubMed

    Quang, Timothy; Tran, Emily Q; Schwarz, Richard A; Williams, Michelle D; Vigneswaran, Nadarajah; Gillenwater, Ann M; Richards-Kortum, Rebecca

    2017-10-01

    The 5-year survival rate for patients with oral cancer remains low, in part because diagnosis often occurs at a late stage. Early and accurate identification of oral high-grade dysplasia and cancer can help improve patient outcomes. Multimodal optical imaging is an adjunctive diagnostic technique in which autofluorescence imaging is used to identify high-risk regions within the oral cavity, followed by high-resolution microendoscopy to confirm or rule out the presence of neoplasia. Multimodal optical images were obtained from 206 sites in 100 patients. Histologic diagnosis, either from a punch biopsy or an excised surgical specimen, was used as the gold standard for all sites. Histopathologic diagnoses of moderate dysplasia or worse were considered neoplastic. Images from 92 sites in the first 30 patients were used as a training set to develop automated image analysis methods for identification of neoplasia. Diagnostic performance was evaluated prospectively using images from 114 sites in the remaining 70 patients as a test set. In the training set, multimodal optical imaging with automated image analysis correctly classified 95% of nonneoplastic sites and 94% of neoplastic sites. Among the 56 sites in the test set that were biopsied, multimodal optical imaging correctly classified 100% of nonneoplastic sites and 85% of neoplastic sites. Among the 58 sites in the test set that corresponded to a surgical specimen, multimodal imaging correctly classified 100% of nonneoplastic sites and 61% of neoplastic sites. These findings support the potential of multimodal optical imaging to aid in the early detection of oral cancer. Cancer Prev Res; 10(10); 563-70. ©2017 AACR. ©2017 American Association for Cancer Research.

  16. Online hyperspectral imaging system for evaluating quality of agricultural products

    NASA Astrophysics Data System (ADS)

    Mo, Changyeun; Kim, Giyoung; Lim, Jongguk

    2017-06-01

    The consumption of fresh-cut agricultural produce in Korea has been growing. The browning of fresh-cut vegetables that occurs during storage and foreign substances such as worms and slugs are some of the main causes of consumers' concerns with respect to safety and hygiene. The purpose of this study is to develop an on-line system for evaluating quality of agricultural products using hyperspectral imaging technology. The online evaluation system with single visible-near infrared hyperspectral camera in the range of 400 nm to 1000 nm that can assess quality of both surfaces of agricultural products such as fresh-cut lettuce was designed. Algorithms to detect browning surface were developed for this system. The optimal wavebands for discriminating between browning and sound lettuce as well as between browning lettuce and the conveyor belt were investigated using the correlation analysis and the one-way analysis of variance method. The imaging algorithms to discriminate the browning lettuces were developed using the optimal wavebands. The ratio image (RI) algorithm of the 533 nm and 697 nm images (RI533/697) for abaxial surface lettuce and the ratio image algorithm (RI533/697) and subtraction image (SI) algorithm (SI538-697) for adaxial surface lettuce had the highest classification accuracies. The classification accuracy of browning and sound lettuce was 100.0% and above 96.0%, respectively, for the both surfaces. The overall results show that the online hyperspectral imaging system could potentially be used to assess quality of agricultural products.

  17. Role of Imaging in the Evaluation of Male Infertility.

    PubMed

    Mittal, Pardeep K; Little, Brent; Harri, Peter A; Miller, Frank H; Alexander, Lauren F; Kalb, Bobby; Camacho, Juan C; Master, Viraj; Hartman, Matthew; Moreno, Courtney C

    2017-01-01

    Infertility is defined herein as the inability to achieve pregnancy after frequently engaging in unprotected sexual intercourse for 1 year. Among infertile couples, the cause of infertility involves the male partner in approximately 50% of cases. Male infertility is usually caused by conditions affecting sperm production, sperm function, or both, or blockages that prevent the delivery of sperm. Chronic health problems, injuries, lifestyle choices, anatomic problems, hormonal imbalances, and genetic defects can have a role in male infertility. The diagnostic workup of male infertility should include a thorough medical and reproductive history, physical examination, and semen analysis, followed by imaging. The main role of imaging is identification of the causes of infertility, such as congenital anomalies and disorders that obstruct sperm transport and may be correctable. Scrotal ultrasonography is the most common initially performed noninvasive examination used to image the male reproductive system, including the testes and extratesticular structures such as the epididymis. Magnetic resonance (MR) imaging is another noninvasive imaging modality used in the pelvis to evaluate possible obstructive lesions involving the ductal system. MR imaging of the brain is extremely useful for evaluating relevant neurologic abnormalities, such as pituitary gland disorders, that are suspected on the basis of hormone analysis results. Invasive techniques are usually reserved for therapeutic interventions in patients with known abnormalities. In this article, the causes and imaging findings of obstructive and nonobstructive azoospermia are discussed. In addition to detecting treatable conditions that are related to male infertility, identifying the life-threatening entities associated with infertility and the genetic conditions that could be transmitted to offspring-especially in patients who undergo assisted reproduction-is critical. (©)RSNA, 2017.

  18. Quantitative evaluation of phase processing approaches in susceptibility weighted imaging

    NASA Astrophysics Data System (ADS)

    Li, Ningzhi; Wang, Wen-Tung; Sati, Pascal; Pham, Dzung L.; Butman, John A.

    2012-03-01

    Susceptibility weighted imaging (SWI) takes advantage of the local variation in susceptibility between different tissues to enable highly detailed visualization of the cerebral venous system and sensitive detection of intracranial hemorrhages. Thus, it has been increasingly used in magnetic resonance imaging studies of traumatic brain injury as well as other intracranial pathologies. In SWI, magnitude information is combined with phase information to enhance the susceptibility induced image contrast. Because of global susceptibility variations across the image, the rate of phase accumulation varies widely across the image resulting in phase wrapping artifacts that interfere with the local assessment of phase variation. Homodyne filtering is a common approach to eliminate this global phase variation. However, filter size requires careful selection in order to preserve image contrast and avoid errors resulting from residual phase wraps. An alternative approach is to apply phase unwrapping prior to high pass filtering. A suitable phase unwrapping algorithm guarantees no residual phase wraps but additional computational steps are required. In this work, we quantitatively evaluate these two phase processing approaches on both simulated and real data using different filters and cutoff frequencies. Our analysis leads to an improved understanding of the relationship between phase wraps, susceptibility effects, and acquisition parameters. Although homodyne filtering approaches are faster and more straightforward, phase unwrapping approaches perform more accurately in a wider variety of acquisition scenarios.

  19. OH* imager response to turbulence-induced temperature fluctuations

    NASA Astrophysics Data System (ADS)

    Gardner, Chester S.; Vargas, Fabio A.

    2016-12-01

    The layer of the excited state hydroxyl radical (OH*) is formed in the mesopause region by the reaction of ozone (O3) and atomic hydrogen (H). We derive the theoretical expressions for the OH* brightness and rotational temperature (T*) responses to high-frequency atmospheric temperature perturbations. The theory is used to calculate the 1-D and 2-D horizontal wave number spectra of the OH* and T* image fluctuations induced by atmospheric turbulence. By applying the theory to images of a breaking gravity wave packet, acquired by the Utah State University Advanced Mesospheric Temperature Mapper, we show that existing infrared OH* imager technology can observe the evolution of gravity wave breakdown and characterize the resulting turbulent eddies in the source region and in the inertial subrange of the turbulence spectrum. For the example presented here, the RMS OH* brightness fluctuations induced by the gravity wave packet was 2.90% and by the associated turbulence was 1.07%. Unfortunately, the T* fluctuations induced by turbulence are usually too small to be observed in the OH* rotational temperature maps.

  20. Radiation dose detection by imaging response in biological targets.

    PubMed

    Jakob, B; Durante, M

    2012-04-01

    Imaging was one of the earliest techniques to quantify radiation dose. While films and active fluorescent detectors are still commonly used in physical dosimetry, biological imaging is emerging as a new method to visualize and quantify radiation dose in biological targets. Methods for biological imaging are normally based on molecular fluorescent probes, labeling chromatin-conjugated molecules or specific repair proteins. Examples are chromatin-binding coumarin compounds, which become fluorescent under irradiation, or the H2AX histone, which is rapidly phosphorylated at sites of DNA double-strand breaks and can be visualized by immunostaining. Many other DNA repair proteins can be expressed with fluorescent targets, such as green fluorescent protein, thus becoming visible for dose estimation in vivo. The possibility to visualize radiation damage in living biological targets is particularly important for repair kinetic studies, for estimating individual radiation response, and for remote control of living samples exposed to radiation, for instance in robotic space missions. In vivo dose monitoring in particle therapy exploits the production of positron emitters by nuclear interaction of the incident beam in the patient's body. Positron emission tomography (PET) can then be used to visualize and quantify the particle dose in the patient, and it can in principle also be used for radiotherapy with high-energy X rays. Alternatively, prompt γ rays or scattered secondary particles are under study for in vivo dosimetry of ion beams in therapy.

  1. Computed tomography and magnetic resonance imaging evaluation of pericardial disease

    PubMed Central

    Shahid, Muhammad; Watkin, Richard W.

    2016-01-01

    Pericardial diseases are commonly encountered in clinical practice and may present as an isolated process or in association with various systemic conditions. Traditionally transthoracic echocardiography (TTE) has been the method of choice for the evaluation of suspected pericardial disease but increasingly computed tomography (CT) and magnetic resonance imaging (MRI) are also being used as part of a rational multi-modality imaging approach tailored to the specific clinical scenario. This paper reviews the role of CT and MRI across the spectrum of pericardial diseases. PMID:27429911

  2. Evaluation of refocus criteria for holographic particle imaging

    NASA Astrophysics Data System (ADS)

    Picart, Pascal; Kara Mohammed, Soumaya; Bouamama, Larbi; Bahloul, Derradji

    2017-06-01

    This paper proposes a quality assessment of focusing criteria for imaging in digital off-axis holography. In literature, several refocus criteria have been proposed in the past to get the best refocus distance in digital holography. As a general rule, the best focusing plane is determined by the reconstruction distance for which the criterion function presents a maximum or a minimum. To evaluate the robustness of these criteria, a set of thirteen criteria is compared with application on both amplitude and phase images from off-axis holographic data. Experimental results lead to define general rule and to exhibit the most robust criteria for accurate and rapid refocusing in digital holography.

  3. Multimodal image coregistration and inducible selective cell ablation to evaluate imaging ligands.

    PubMed

    Virostko, John; Henske, Joseph; Vinet, Laurent; Lamprianou, Smaragda; Dai, Chunhua; Radhika, Aramandla; Baldwin, Ronald M; Ansari, Mohammad S; Hefti, Franz; Skovronsky, Daniel; Kung, Hank F; Herrera, Pedro L; Peterson, Todd E; Meda, Paolo; Powers, Alvin C

    2011-12-20

    We combined multimodal imaging (bioluminescence, X-ray computed tomography, and PET), tomographic reconstruction of bioluminescent sources, and two unique, complementary models to evaluate three previously synthesized PET radiotracers thought to target pancreatic beta cells. The three radiotracers {[(18)F]fluoropropyl-(+)-dihydrotetrabenazine ([(18)F]FP-DTBZ), [(18)F](+)-2-oxiranyl-3-isobutyl-9-(3-fluoropropoxy)-10-methoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinoline ((18)F-AV-266), and (2S,3R,11bR)-9-(3-fluoropropoxy)-2-(hydroxymethyl)-3-isobutyl-10-methoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol ((18)F-AV-300)} bind vesicular monoamine transporter 2. Tomographic reconstruction of the bioluminescent signal in mice expressing luciferase only in pancreatic beta cells was used to delineate the pancreas and was coregistered with PET and X-ray computed tomography images. This strategy enabled unambiguous identification of the pancreas on PET images, permitting accurate quantification of the pancreatic PET signal. We show here that, after conditional, specific, and rapid mouse beta-cell ablation, beta-cell loss was detected by bioluminescence imaging but not by PET imaging, given that the pancreatic signal provided by three PET radiotracers was not altered. To determine whether these ligands bound human beta cells in vivo, we imaged mice transplanted with luciferase-expressing human islets. The human islets were imaged by bioluminescence but not with the PET ligands, indicating that these vesicular monoamine transporter 2-directed ligands did not specifically bind beta cells. These data demonstrate the utility of coregistered multimodal imaging as a platform for evaluation and validation of candidate ligands for imaging islets.

  4. Gastric carcinoma: imaging diagnosis, staging and assessment of treatment response

    PubMed Central

    Hallinan, James Thomas Patrick Decourcy

    2013-01-01

    Abstract Gastric carcinoma (GC) is one of the most common causes of cancer-related death worldwide. Surgical resection is the only cure available and is dependent on the GC stage at presentation, which incorporates depth of tumor invasion, extent of lymph node and distant metastases. Accurate preoperative staging is therefore essential for optimal surgical management with consideration of preoperative and/or postoperative chemotherapy. Multidetector computed tomography (MDCT) with its ability to assess tumor depth, nodal disease and metastases is the preferred technique for staging GC. Endoscopic ultrasonography is more accurate for assessing the depth of wall invasion in early cancer, but is limited in the assessment of advanced local or stenotic cancer and detection of distant metastases. Magnetic resonance imaging (MRI), although useful for staging, is not proven to be effective. Positron emission tomography (PET) is most useful for detecting and characterizing distant metastases. Both MDCT and PET are useful for assessment of treatment response following preoperative chemotherapy and for detection of recurrence after surgical resection. This review article discusses the usefulness of imaging modalities for detecting, staging and assessing treatment response for GC and the potential role of newer applications including CT volumetry, virtual gastroscopy and perfusion CT in the management of GC. PMID:23722535

  5. Detection of early plant stress responses in hyperspectral images

    NASA Astrophysics Data System (ADS)

    Behmann, Jan; Steinrücken, Jörg; Plümer, Lutz

    2014-07-01

    Early stress detection in crop plants is highly relevant, but hard to achieve. We hypothesize that close range hyperspectral imaging is able to uncover stress related processes non-destructively in the early stages which are invisible to the human eye. We propose an approach which combines unsupervised and supervised methods in order to identify several stages of progressive stress development from series of hyperspectral images. Stress of an entire plant is detected by stress response levels at pixel scale. The focus is on drought stress in barley (Hordeum vulgare). Unsupervised learning is used to separate hyperspectral signatures into clusters related to different stages of stress response and progressive senescence. Whereas all such signatures may be found in both, well watered and drought stressed plants, their respective distributions differ. Ordinal classification with Support Vector Machines (SVM) is used to quantify and visualize the distribution of progressive stages of senescence and to separate well watered from drought stressed plants. For each senescence stage a distinctive set of most relevant Vegetation Indices (VIs) is identified. The method has been applied on two experiments involving potted barley plants under well watered and drought stress conditions in a greenhouse. Drought stress is detected up to ten days earlier than using NDVI. Furthermore, it is shown that some VIs have overall relevance, while others are specific to particular senescence stages. The transferability of the method to the field is illustrated by an experiment on maize (Zea mays).

  6. Functional Imaging of the Hemodynamic Sensory Gating Response in Schizophrenia

    PubMed Central

    Mayer, Andrew R.; Ruhl, David; Merideth, Flannery; Ling, Josef; Hanlon, Faith; Bustillo, Juan; Cañive, Jose

    2013-01-01

    The cortical (auditory and prefrontal) and/or subcortical (thalamic and hippocampal) generators of abnormal electrophysiological responses during sensory gating remain actively debated in the schizophrenia literature. Functional magnetic resonance imaging (fMRI) has the spatial resolution for disambiguating deep or simultaneous sources but has been relatively under-utilized to investigate generators of the gating response. Thirty patients with chronic schizophrenia (SP) and 30 matched controls participated in the current experiment. Hemodynamic response functions (HRF) for single (S1) and pairs (S1 + S2) of identical (IT; “gating-out” redundant information) or non-identical (NT; “gating-in” novel information) tones were generated through deconvolution. Increased or prolonged activation for patients in conjunction with deactivation for controls was observed within auditory cortex, prefrontal cortex and thalamus in response to single tones during the late hemodynamic response, and these group differences were not associated with clinical or cognitive symptomatology. Although patient hyper-activation to paired-tones conditions was present in several ROI, the effects were not statistically significant for either the gating-out or gating-in conditions. Finally, abnormalities in the post-undershoot of the auditory HRF were also observed for both single and paired tones conditions in patients. In conclusion, the amalgamation of the entire electrophysiological response to both S1 and S2 stimuli may limit hemodynamic sensitivity to paired tones during sensory gating, which may be more readily overcome by paradigms that utilize multiple stimuli rather than pairs. Patient hyperactivation following single tones is suggestive of deficits in basic inhibition, neurovascular abnormalities or a combination of both factors. PMID:22461278

  7. Children's Responses to the Medical Evaluation for Child Sexual Abuse.

    ERIC Educational Resources Information Center

    Dubowitz, Howard

    1998-01-01

    Addresses three issues: (1) how children respond to the medical evaluation for sexual abuse; (2) how the trauma of the evaluation experienced by some children can be minimized and the benefits maximized; and (3) how children's responses to the medical evaluation for sexual abuse can be interpreted. (DB)

  8. Validation of functional imaging as a biomarker for radiation treatment response.

    PubMed

    Jentsch, C; Beuthien-Baumann, B; Troost, E G C; Shakirin, G

    2015-07-01

    Major advances in radiotherapy techniques, increasing knowledge of tumour biology and the ability to translate these advances into new therapeutic approaches are important goals towards more individualized cancer treatment. With the development of non-invasive functional and molecular imaging techniques such as positron emission tomography (PET)-CT scanning and MRI, there is now a need to evaluate potential new biomarkers for tumour response prediction, for treatment individualization is not only based on morphological criteria but also on biological tumour characteristics. The goal of individualization of radiotherapy is to improve treatment outcome and potentially reduce chronic treatment toxicity. This review gives an overview of the molecular and functional imaging modalities of tumour hypoxia and tumour cell metabolism, proliferation and perfusion as predictive biomarkers for radiation treatment response in head and neck tumours and in lung tumours. The current status of knowledge on integration of PET/CT/MRI into treatment management and bioimage-guided adaptive radiotherapy are discussed.

  9. Local and global evaluation for remote sensing image segmentation

    NASA Astrophysics Data System (ADS)

    Su, Tengfei; Zhang, Shengwei

    2017-08-01

    In object-based image analysis, how to produce accurate segmentation is usually a very important issue that needs to be solved before image classification or target recognition. The study for segmentation evaluation method is key to solving this issue. Almost all of the existent evaluation strategies only focus on the global performance assessment. However, these methods are ineffective for the situation that two segmentation results with very similar overall performance have very different local error distributions. To overcome this problem, this paper presents an approach that can both locally and globally quantify segmentation incorrectness. In doing so, region-overlapping metrics are utilized to quantify each reference geo-object's over and under-segmentation error. These quantified error values are used to produce segmentation error maps which have effective illustrative power to delineate local segmentation error patterns. The error values for all of the reference geo-objects are aggregated through using area-weighted summation, so that global indicators can be derived. An experiment using two scenes of very different high resolution images showed that the global evaluation part of the proposed approach was almost as effective as other two global evaluation methods, and the local part was a useful complement to comparing different segmentation results.

  10. Evaluation of protection measures against laser dazzling for imaging sensors

    NASA Astrophysics Data System (ADS)

    Ritt, Gunnar; Eberle, Bernd

    2016-10-01

    We present the latest results of our work regarding the evaluation of protection measures against laser dazzling for imaging devices. Three different approaches for the evaluation of dazzled sensor images are investigated and compared to estimate the loss of information due to the dazzle spot by a) counting the number of overexposed pixels, b) based on triangle orientation discrimination (TOD) and c) using the structural similarity (SSIM) index. The performance evaluation approaches are applied on experimental data obtained with two different imaging sensors hardened against laser dazzling. The hardening concept of the first sensor is based on the combination of a spatial light modulator and wavelength multiplexing. This active protection concept allows spatially and spectrally resolved suppression of laser radiation within the sensor's field of view. The hardening concept of the second sensor utilizes the principle of "complementary bands". The optical setup resembles a common 3-chip camera, with the difference that dedicated filters with steep edges replace the regular spectral band filters. Although this concept does not really represent a "protection measure", it allows the sensor to provide information even in laser dazzling situations. The data for the performance evaluation was acquired both in a dedicated laboratory setup using test charts comprising triangles of different size and orientation as well as in field trials.

  11. Update on Magnetic Resonance Imaging and Ultrasound Evaluation of Crohn’s Disease

    PubMed Central

    Deepak, Parakkal; Kolbe, Amy B.; Fidler, Jeff L.; Fletcher, Joel G.; Knudsen, John M.

    2016-01-01

    Magnetic resonance enterography (MRE) and abdominal ultrasound are integral parts of multimodality assessments for patients with inflammatory bowel disease. Applications include assessing Crohn’s disease (CD) extent and severity, differentiating CD from ulcerative colitis, detecting CD complications, evaluating response to therapy, and demonstrating postoperative recurrence. Magnetic resonance imaging protocols are being developed that may reduce or eliminate the need for intravenous contrast agents and better differentiate inflammatory from fibrotic strictures. MRE scoring systems have been created to objectively quantify disease activity and response to therapy. By utilizing advanced sonographic imaging techniques, including ultrasound contrast and Doppler assessments, the role of abdominal ultrasonography in the evaluation and management of CD continues to expand. Abdominal ultrasound may function as a low-cost, point-of care assessment tool, especially in CD restricted to the terminal ileum and ileocolic anastomosis. PMID:27231453

  12. Physiological Imaging-Defined, Response-Driven Subvolumes of a Tumor

    SciTech Connect

    Farjam, Reza; Tsien, Christina I.; Feng, Felix Y.; Gomez-Hassan, Diana; Hayman, James A.; Lawrence, Theodore S.; Cao, Yue

    2013-04-01

    Purpose: To develop an image analysis framework to delineate the physiological imaging-defined subvolumes of a tumor in relating to treatment response and outcome. Methods and Materials: Our proposed approach delineates the subvolumes of a tumor based on its heterogeneous distributions of physiological imaging parameters. The method assigns each voxel a probabilistic membership function belonging to the physiological parameter classes defined in a sample of tumors, and then calculates the related subvolumes in each tumor. We applied our approach to regional cerebral blood volume (rCBV) and Gd-DTPA transfer constant (K{sup trans}) images of patients who had brain metastases and were treated by whole-brain radiation therapy (WBRT). A total of 45 lesions were included in the analysis. Changes in the rCBV (or K{sup trans})–defined subvolumes of the tumors from pre-RT to 2 weeks after the start of WBRT (2W) were evaluated for differentiation of responsive, stable, and progressive tumors using the Mann-Whitney U test. Performance of the newly developed metrics for predicting tumor response to WBRT was evaluated by receiver operating characteristic (ROC) curve analysis. Results: The percentage decrease in the high-CBV-defined subvolumes of the tumors from pre-RT to 2W was significantly greater in the group of responsive tumors than in the group of stable and progressive tumors (P<.007). The change in the high-CBV-defined subvolumes of the tumors from pre-RT to 2W was a predictor for post-RT response significantly better than change in the gross tumor volume observed during the same time interval (P=.012), suggesting that the physiological change occurs before the volumetric change. Also, K{sup trans} did not add significant discriminatory information for assessing response with respect to rCBV. Conclusion: The physiological imaging-defined subvolumes of the tumors delineated by our method could be candidates for boost target, for which further development and evaluation

  13. SU-E-J-148: Evaluating Tumor Response with a Commercially Available Deformable Registration System

    SciTech Connect

    Bowling, J; Ramsey, C

    2014-06-01

    Purpose: The purpose of this study is to present a method for evaluating the response to treatment using a commercially available deformable image registration software package (Velocity Medical Systems) and repeat PET/CT imaging. This technique can be used to identify volumes that are risk for tumor recurrence. Methods: Response to treatment was evaluated using PET/CT images acquired prior-to and post-treatment for radiation therapy patients treated with concurrent chemotherapy. Velocity (Version 3.0.1) was used to deform the initial PET/CT to the post treatment PET/CT. The post-treatment PET images were then subtracted from the pre-treatment PET images. The resulting re-sampled image is a three-dimensional SUV difference map that shows pixels with increasing SUV values. SUV values increases greater than 2.5 in the post treatment images were identified for additional follow-up. Results: A total of 5 Lung patients were analyzed as part of this study. One lung patient in the cohort had an SUV increase of +3.28 that was identified using the SUV difference map. This volume of increased uptake was located outside the treatment field and adjacent to the 35 Gy isodose line. The remaining four patients all had SUV decreases inside the planning target volume, and no unexpected areas of increase outside the irradiated volumes. All five patients were analyzed using standard tools inside the Velocity application. Conclusion: The response to treatment can easily be measured using serial PET/CT images and a commercially available deformable image registration. This provides both the radiation oncologists and medical oncologists with a quantitative assessment of their treatment to use in patient follow-up.

  14. Quantitative performance evaluation of the EM algorithm applied to radiographic images

    NASA Astrophysics Data System (ADS)

    Brailean, James C.; Giger, Maryellen L.; Chen, Chin-Tu; Sullivan, Barry J.

    1991-07-01

    In this study, the authors evaluate quantitatively the performance of the Expectation Maximization (EM) algorithm as a restoration technique for radiographic images. The 'perceived' signal-to-nose ratio (SNR), of simple radiographic patterns processed by the EM algorithm are calculated on the basis of a statistical decision theory model that includes both the observer's visual response function and a noise component internal to the eye-brain system. The relative SNR (ratio of the processed SNR to the original SNR) is calculated and used as a metric to quantitatively compare the effects of the EM algorithm to two popular image enhancement techniques: contrast enhancement (windowing) and unsharp mask filtering.

  15. Molecular imaging using contrast-enhanced ultrasound: evaluation of angiogenesis and cell therapy.

    PubMed

    Leong-Poi, Howard

    2009-11-01

    The field of regenerative medicine and its applications for cardiovascular diseases continues to grow rapidly, fuelled by the increasing numbers of symptomatic patients who are not candidates for conventional revascularization procedures and remain refractory to maximal medical therapy. Therapeutic angiogenesis, initially in the form of the administration of growth factor protein or gene therapy and, more recently, in the form of adult progenitor cell therapy, has emerged as a promising new method of treatment for patients with ischaemic heart disease and peripheral arterial disease. There is a growing interest in non-invasive imaging techniques to evaluate the response to angiogenic gene-and cell-based therapies. Contrast-enhanced ultrasound (CEU) techniques using site-specific microbubbles have recently been developed for the molecular imaging of the vascular phenotype that characterizes angiogenesis. These methods have now been modified to allow the imaging of progenitor cell engraftment into neovessels. These molecular imaging techniques using contrast ultrasound and targeted microbubbles have the potential to further characterize the angiogenic response, aid in the optimization of gene- and cell-based strategies of therapeutic neovascularization, and ultimately serve to monitor the therapeutic effects in patients enrolled in clinical trials of regenerative therapies. This review will focus specifically on CEU molecular imaging techniques for the evaluation of angiogenesis and cell therapies in cardiovascular diseases, including: (i) an overview of the techniques and results of pre-clinical studies; (ii) a comparison of CEU molecular imaging techniques with other available molecular imaging modalities; and (iii) a discussion of the future role of CEU molecular imaging in the field of regenerative medicine.

  16. Evaluation of Two Fractal Methods for Magnetogram Image Analysis

    NASA Technical Reports Server (NTRS)

    Stark, B.; Adams, M.; Hathaway, D. H.; Hagyard, M. J.

    1997-01-01

    Fractal and multifractal techniques have been applied to various types of solar data to study the fractal properties of sunspots as well as the distribution of photospheric magnetic fields and the role of random motions on the solar surface in this distribution. Other research includes the investigation of changes in the fractal dimension as an indicator for solar flares. Here we evaluate the efficacy of two methods for determining the fractal dimension of an image data set: the Differential Box Counting scheme and a new method, the Jaenisch scheme. To determine the sensitivity of the techniques to changes in image complexity, various types of constructed images are analyzed. In addition, we apply this method to solar magnetogram data from Marshall Space Flight Centers vector magnetograph.

  17. An image method to evaluate bagasse fiber dimensions.

    PubMed

    Chiparus, Ovidiu I; Chen, Yan

    2003-12-01

    In the last 25 years the amount of textile nonwovens used for industrial and commercial applications increased more than 10 times. Bagasse fiber, a by-product from sugar cane industry, provides a natural resource for nonwoven industries. Even though underrated as a potential fiber, bagasse comes more and more into attention because of the increasing concern for disposal of agricultural residuals and the need for enhancing the sugar cane industry's profitability. However, there is a lack of an instrumental method to evaluate bagasse fiber length and fineness. This paper presents a study on measuring the bagasse fineness using image analysis method. Cross-sections images of bagasse fibers were visualized using Scanning Electronic Microscopy (SEM). The computing software Scion Image was used to measure bagasse fiber length and cross-sectional area. Relationship between fiber fineness and cross-sectional area was analyzed using the statistical method of regression.

  18. Evaluation of Two Fractal Methods for Magnetogram Image Analysis

    NASA Technical Reports Server (NTRS)

    Stark, B.; Adams, M.; Hathaway, D. H.; Hagyard, M. J.

    1997-01-01

    Fractal and multifractal techniques have been applied to various types of solar data to study the fractal properties of sunspots as well as the distribution of photospheric magnetic fields and the role of random motions on the solar surface in this distribution. Other research includes the investigation of changes in the fractal dimension as an indicator for solar flares. Here we evaluate the efficacy of two methods for determining the fractal dimension of an image data set: the Differential Box Counting scheme and a new method, the Jaenisch scheme. To determine the sensitivity of the techniques to changes in image complexity, various types of constructed images are analyzed. In addition, we apply this method to solar magnetogram data from Marshall Space Flight Centers vector magnetograph.

  19. Numerical evaluation of linearized image reconstruction based on finite element method for biomedical photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Okawa, Shinpei; Hirasawa, Takeshi; Kushibiki, Toshihiro; Ishihara, Miya

    2013-09-01

    An image reconstruction algorithm for biomedical photoacoustic imaging is discussed. The algorithm solves the inverse problem of the photoacoustic phenomenon in biological media and images the distribution of large optical absorption coefficients, which can indicate diseased tissues such as cancers with angiogenesis and the tissues labeled by exogenous photon absorbers. The linearized forward problem, which relates the absorption coefficients to the detected photoacoustic signals, is formulated by using photon diffusion and photoacoustic wave equations. Both partial differential equations are solved by a finite element method. The inverse problem is solved by truncated singular value decomposition, which reduces the effects of the measurement noise and the errors between forward modeling and actual measurement systems. The spatial resolution and the robustness to various factors affecting the image reconstruction are evaluated by numerical experiments with 2D geometry.

  20. Evaluation of the pituitary gland using magnetic resonance imaging: T1-weighted vs. VIBE imaging.

    PubMed

    Davis, M A; Castillo, M

    2013-06-01

    Volumetric interpolated breath-hold examination (VIBE) is used for abdominal imaging as a fast and efficient modality. Evaluation of brain lesions using VIBE is not common and its use for the pituitary gland has not yet been addressed. Our goal was to compare coronal T1-weighted (T1W) and VIBE images in patients undergoing studies of the pituitary gland. We hypothesized that, for this purpose, VIBE is superior to T1W images. T1W and VIBE images of the pituitary gland in 32 patients were evaluated. The two sequences were compared with specific attention to: contrast enhancement (gland and cavernous sinuses) and ability to view the anatomy of the cavernous sinuses. In patients with macroadenomas, visualization of the optic chiasm was also assessed. Images were rated as: VIBE being better, equal, or worse in comparison to T1W images. We also compared VIBE and T1W images specifically looking at micro/macro-adenomas and post-surgical patients. Statistical analysis was performed using chi-square statistics. Of the 32 patients, the VIBE sequence showed superior contrast enhancement in 18 patients, six were found as being equal to T1W, and in eight instances VIBE was found to be worse than T1W. These results were statistically significant (p=.02). When looking at micro/macro-adenomas and post-surgical patients specifically, there was a trend to VIBE being superior to T1W but these data were not statistically significant. Visualization of chiasm in macroadenomas was similar for both techniques. VIBE was significantly superior to T1W with respect to pituitary and cavernous sinus contrast enhancement and cavernous sinus anatomy. A trend towards VIBE being superior in the evaluation of adenomas (pre- and post-operative) was seen, but it was not statistically significant. This is likely due to the small population size.

  1. Functional Imaging in OA: Role of Imaging in the Evaluation of Tissue Biomechanics

    PubMed Central

    Neu, Corey P.

    2014-01-01

    Functional imaging refers broadly to the visualization of organ or tissue physiology using medical image modalities. In load-bearing tissues of the body, including articular cartilage lining the bony ends of joints, changes in strain, stress, and material properties occur in osteoarthritis (OA), providing an opportunity to probe tissue function through the progression of the disease. Here, biomechanical measures in cartilage and related joint tissues are discussed as key imaging biomarkers in the evaluation of OA. Emphasis will be placed on the a) potential of radiography, ultrasound, and magnetic resonance imaging to assess early tissue pathomechanics in OA, b) relative utility of kinematic, structural, morphological, and biomechanical measures as functional imaging biomarkers, and c) improved diagnostic specificity through the combination of multiple imaging biomarkers with unique contrasts, including elastography and quantitative assessments of tissue biochemistry. In comparison to other modalities, magnetic resonance imaging provides an extensive range of functional measures at the tissue level, with conventional and emerging techniques available to potentially to assess the spectrum of preclinical to advance OA. PMID:25278049

  2. Localization of the cortical response to smiling using new imaging paradigms with functional magnetic resonance imaging.

    PubMed

    Gosain, A K; Birn, R M; Hyde, J S

    2001-10-01

    Functional magnetic resonance imaging (fMRI) can serve to localize activity in the cerebral cortex. The present study was performed to develop a quantitative means of describing the cortical location activated during voluntary smiling in multiple subjects and to determine whether this location is specific to smiling when compared with other motor tasks. Five human subjects were instructed to smile or to tap the fingers of both hands. Both tasks were performed in a blocked-trial paradigm that consisted of alternating 15-second blocks of a repetitive motor task and 15 seconds of rest. Smiling was also performed as an event-related paradigm in which the subject smiled briefly once every 15 seconds for 20 repetitions that were combined to produce an average response to a single smile. A series of 300 images was acquired using an echo-planar imaging sequence (24-cm field of view; 5-mm slice thickness; repetition time/echo time, 1000/27.2 msec). Each subject's three-dimensional brain images were transformed to Talairach coordinates by stretching or compressing the brain images to fit the standard brain as defined in the Talairach atlas. This allowed data from five subjects to be combined for a numeric description. Functional activation maps acquired by use of the event-related paradigm contained significantly fewer motion artifacts than maps acquired with the blocked-trial paradigm, allowing better visualization of functionally active areas. Three-dimensional Talairach coordinates to describe the locations of peak cortical activity after smiling and finger tapping were established. These coordinates were consistent among subjects. During smiling, statistically significant activation was seen in the motor cortex, primarily along the precentral sulcus; this was inferior and anterior to the region that was associated with finger tapping. This study demonstrates that motion artifacts associated with traditional blocked-trial fMRI protocols can be overcome by employing an

  3. Image reconstruction and image quality evaluation for a dual source CT scanner.

    PubMed

    Flohr, T G; Bruder, H; Stierstorfer, K; Petersilka, M; Schmidt, B; McCollough, C H

    2008-12-01

    The authors present and evaluate concepts for image reconstruction in dual source CT (DSCT). They describe both standard spiral (helical) DSCT image reconstruction and electrocardiogram (ECG)-synchronized image reconstruction. For a compact mechanical design of the DSCT, one detector (A) can cover the full scan field of view, while the other detector (B) has to be restricted to a smaller, central field of view. The authors develop an algorithm for scan data completion, extrapolating truncated data of detector (B) by using data of detector (A). They propose a unified framework for convolution and simultaneous 3D backprojection of both (A) and (B) data, with similar treatment of standard spiral, ECG-gated spiral, and sequential (axial) scan data. In ECG-synchronized image reconstruction, a flexible scan data range per measurement system can be used to trade off temporal resolution for reduced image noise. Both data extrapolation and image reconstruction are evaluated by means of computer simulated data of anthropomorphic phantoms, by phantom measurements and patient studies. The authors show that a consistent filter direction along the spiral tangent on both detectors is essential to reduce cone-beam artifacts, requiring truncation of the extrapolated (B) data after convolution in standard spiral scans. Reconstructions of an anthropomorphic thorax phantom demonstrate good image quality and dose accumulation as theoretically expected for simultaneous 3D backprojection of the filtered (A) data and the truncated filtered (B) data into the same 3D image volume. In ECG-gated spiral modes, spiral slice sensitivity profiles (SSPs) show only minor dependence on the patient's heart rate if the spiral pitch is properly adapted. Measurements with a thin gold plate phantom result in effective slice widths (full width at half maximum of the SSP) of 0.63-0.69 mm for the nominal 0.6 mm slice and 0.82-0.87 mm for the nominal 0.75 mm slice. The visually determined through-plane (z

  4. Tool Support to Enable Evaluation of the Clinical Response to Treatment

    PubMed Central

    Levy, Mia A.; Rubin, Daniel L.

    2008-01-01

    Objective criteria for measuring response to cancer treatment are critical to clinical research and practice. The National Cancer Institute has developed the Response Evaluation Criteria in Solid Tumors (RECIST)1 method to quantify treatment response. RECIST evaluates response by assessing a set of measurable target lesions in baseline and follow-up radiographic studies. However, applying RECIST consistently is challenging due to inter-observer variability among oncologists and radiologists in choice and measurement of target lesions. We analyzed the radiologist-oncologist workflow to determine whether the information collected is sufficient for reliably applying RECIST. We evaluated radiology reports and image markup (radiologists), and clinical flow sheets (oncologists). We found current reporting of radiology results insufficient for consistent application of RECIST, compared with flow sheets. We identified use cases and functional requirements for an informatics tool that could improve consistency and accuracy in applying methods such as RECIST. PMID:18998923

  5. Evaluating Photogrammetric Approach of Image-Based Positioning

    NASA Astrophysics Data System (ADS)

    Li, X.; Wang, J.

    2012-07-01

    In recent years, researches in the domain of location-based services have increasingly focused on developing and utilizing alternative positioning techniques for in GPS-denied environment. Image based positioning technique holds good promise for such applications. In this paper, a previously proposed image-based positioning system using photogrammetric methods has been put into rigorous evaluation. The precision and accuracy of such photogrammetric approach of image-based positioning is depending on the precision and accuracy of final space resection process, which is a function of PGCP distribution and measurement accuracy, and any factor that has certain impact on either of these two major components will to certain degree influence final positioning accuracy. Therefore in this article, the way that different factors influencing the positioning accuracy are analysed through both mathematical model and experiments, which includes simulations and tests based on real data. Through evaluation of such system, we aims at better understanding image-based positioning system alike so as to find its strength, weaknesses and ways to improve the overall performance for it to realize its full potential.

  6. Genetic programming approach to evaluate complexity of texture images

    NASA Astrophysics Data System (ADS)

    Ciocca, Gianluigi; Corchs, Silvia; Gasparini, Francesca

    2016-11-01

    We adopt genetic programming (GP) to define a measure that can predict complexity perception of texture images. We perform psychophysical experiments on three different datasets to collect data on the perceived complexity. The subjective data are used for training, validation, and test of the proposed measure. These data are also used to evaluate several possible candidate measures of texture complexity related to both low level and high level image features. We select four of them (namely roughness, number of regions, chroma variance, and memorability) to be combined in a GP framework. This approach allows a nonlinear combination of the measures and could give hints on how the related image features interact in complexity perception. The proposed complexity measure M exhibits Pearson correlation coefficients of 0.890 on the training set, 0.728 on the validation set, and 0.724 on the test set. M outperforms each of all the single measures considered. From the statistical analysis of different GP candidate solutions, we found that the roughness measure evaluated on the gray level image is the most dominant one, followed by the memorability, the number of regions, and finally the chroma variance.

  7. NIR hyperspectral imaging to evaluate degradation in captopril commercial tablets.

    PubMed

    França, Leandro de Moura; Pimentel, Maria Fernanda; Simões, Simone da Silva; Grangeiro, Severino; Prats-Montalbán, José M; Ferrer, Alberto

    2016-07-01

    Pharmaceutical quality control is important for improving the effectiveness, purity and safety of drugs, as well as for the prevention or control of drug degradation. In the present work, near infrared hyperspectral images (HSI-NIR) of tablets with different expiration dates were employed to evaluate the degradation of captopril into captopril disulfide in different layers, on the top and on the bottom surfaces of the tablets. Multivariate curve resolution (MCR) models were used to extract the concentration distribution maps from the hyperspectral images. Afterward, multivariate image techniques were applied to the concentration distribution maps (CDMs), to extract features and build models relating the main characteristics of the images to their corresponding manufacturing dates. Resolution methods followed by extracting features were able to estimate the tablet manufacture date with a prediction error of 120days. The model developed could be useful to evaluate whether a sample shows a degradation pattern consistent with the date of manufacturing or to detect abnormal behaviors in the natural degradation process of the sample. The information provided by the HIS-NIR is important for the development of the process (QbD), looking inside the formulation, revealing the behavior of the active pharmaceutical ingredient (API) during the product's shelf life. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Evaluating Detection and Diagnostic Decision Support Systems for Bioterrorism Response

    PubMed Central

    Sundaram, Vandana; McDonald, Kathryn M.; Smith, Wendy M.; Szeto, Herbert; Schleinitz, Mark D.; Owens, Douglas K.

    2004-01-01

    We evaluated the usefulness of detection systems and diagnostic decision support systems for bioterrorism response. We performed a systematic review by searching relevant databases (e.g., MEDLINE) and Web sites for reports of detection systems and diagnostic decision support systems that could be used during bioterrorism responses. We reviewed over 24,000 citations and identified 55 detection systems and 23 diagnostic decision support systems. Only 35 systems have been evaluated: 4 reported both sensitivity and specificity, 13 were compared to a reference standard, and 31 were evaluated for their timeliness. Most evaluations of detection systems and some evaluations of diagnostic systems for bioterrorism responses are critically deficient. Because false-positive and false-negative rates are unknown for most systems, decision making on the basis of these systems is seriously compromised. We describe a framework for the design of future evaluations of such systems. PMID:15078604

  9. Sharing stories: narrative and dialogue in responsive nursing evaluation.

    PubMed

    Abma, T A; Widdershoven, G A M

    2005-03-01

    Responsive evaluation is an emerging vision and rationale for nursing evaluation. In this vision, evaluation is redefined as an engagement with all stakeholders about the value and meaning of their practice as a vehicle for learning, understanding, and improvement. In this article, the authors aim to illustrate the utility of a particular version of responsive evaluation, one that is connected with recent ideas about narrative and dialogue. They concentrate on methodological issues and use a case example to illustrate these issues. The case concerns a responsive evaluation of the quality of palliative care for cancer patients in a Dutch region. Methodological issues include the collection of stories through the use of conversational interviews. Stories can reveal the meaning and ambiguity of everyday situations. If evaluators listen to different stories and facilitate a dialogue about stories, this will enhance mutual understandings and promote respect, inclusiveness, and social equity.

  10. IMAGE ENHANCEMENT FOR IMPAIRED VISION: THE CHALLENGE OF EVALUATION.

    PubMed

    Peli, Eli; Woods, Russell L

    2009-06-01

    With the aging of the population, the prevalence of eye diseases and thus of vision impairment is increasing. The TV watching habits of people with vision impairments are comparable to normally sighted people1, however their vision loss prevents them from fully benefiting from this medium. For over 20 years we have been developing video image-enhancement techniques designed to assist people with visual impairments, particularly those due to central retinal vision loss. A major difficulty in this endeavor is the lack of evaluation techniques to assess and compare the effectiveness of various enhancement methods. This paper reviews our approaches to image enhancement and the results we have obtained, with special emphasis on the difficulties encountered in the evaluation of the benefits of enhancement and the solutions we have developed to date.

  11. The Evaluation Of Infrared Imaging Systems Used For Building Inspections

    NASA Astrophysics Data System (ADS)

    Grot, Richard A.; Chang, Yui-May

    1984-03-01

    The results of the laboratory evaluation of three high resolution infrared imaging systems are presented. The systems were evaluated for their minimum resolvable temperature difference (MRTD) at spatial frequencies from 0.02 to 0.16 cycles per milliradian and at ambient temperatures in the range of -7° C to 20° C. The results of these tests are compared with the predicted dependence of the MRTD given in the ASHRAE Standard 101-83. It is shown that the dependence on temperature of the MRTD of two of the systems is predicted well by the theory given in the ASHRAE standard. The calibration curves of the infrared imaging systems are given. These are in good agreement with those given by the manufacturers of the equipment.

  12. Early-phase myocardial infarction: Evaluation by MR imaging

    SciTech Connect

    Tscholakoff, D.; Higgins, C.B.; McNamara, M.T.; Derugin, N.

    1986-06-01

    In vivo gated magnetic resonance (MR) imaging was performed in 12 dogs immediately after occlusion of the left anterior descending coronary artery and serially up to 5 hours and again between 4 and 14 days. This was done to evaluate the appearance of acute myocardial infarcts and to determine how soon after coronary artery occlusion MR imaging can demonstrate the site of acute myocardial ischemia. In nine dogs with postmortem evidence of myocardial infarction, regional increase of signal intensity of the myocardium was present by 3 hours after coronary occlusion and conformed to the site of myocardial infarct found at autopsy. The signal intensity on T2-weighted images of the infarcted on T2-weighted images of the infarcted myocardium was significantly greater than that of normal myocardium at 3, 4, and 5 hours after occlusion. The T2 (spin-spin) relaxation time was significantly prolonged in the region of myocardial infarct at 3, 4, and 5 hours post-occlusion compared with normal myocardium. Myocardial wall thinning and increased intracavitary flow signal were found in six dogs with comparable pre- and postocclusion images in late systole.

  13. Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities

    PubMed Central

    van Bergen, Christiaan JA; Gerards, Rogier M; Opdam, Kim TM; Terra, Maaike P; Kerkhoffs, Gino MMJ

    2015-01-01

    This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available. PMID:26716090

  14. Evaluation of collimation and imaging configuration in scintimammography

    SciTech Connect

    Tsui, B.M.W.; Frey, E.C.; Wessell, D.E.

    1996-12-31

    Conventional scintimammography (SM) with {sup 99m}Tc sestamibi has been limited to taking a single lateral view of the breast using a parallel-hole high resolution (LEHR) collimator. The collimator is placed close to the breast for best possible spatial resolution. However, the collimator geometry precludes imaging the breast from other views. We evaluated using a pinhole collimator instead of a LEHR collimator in SM for improved spatial resolution and detection efficiency, and to allow additional imaging views. Results from theoretical calculations indicated that pinhole collimators could be designed with higher spatial resolution and detection efficiency than LEHR when imaging small to medium size breasts. The geometrical shape of the pinhole collimator allows imaging of the breasts from both the lateral and craniocaudal views. The dual-view images allow better determination of the location of the tumors within the breast and improved detection of tumors located in the medial region of the breast. A breast model that simulates the shape and composition of the breast and breast tumors with different sizes and locations was added to an existing 3D mathematical cardiac-torso (MCAT) phantom. A cylindrically shaped phantom with 10 cm diameter and spherical inserts with different sizes and {sup 99m}Tc sestamibi uptakes with respect to the background provide physical models of breast with tumors. Simulation studies using the breast and MCAT phantoms and experimental studies using the cylindrical phantom confirmed the utility of the pinhole collimator in SM for improved breast tumor detection.

  15. Magnetic resonance imaging in the evaluation of congestive cardiac failure.

    PubMed

    Rajiah, Prabhakar

    2012-07-01

    Congestive cardiac failure is the end-result of various cardiac disorders, and is a major contributor to morbidity, mortality, and financial burden throughout the world. Due to advances in the knowledge of the disease and scanner technology, magnetic resonance imaging (MRI) is playing an increasingly important role in the evaluation of cardiac failure, including in establishing diagnosis, problem solving, risk stratification, and monitoring of therapy. This review discusses and illustrates the role of MRI in the assessment of congestive cardiac failure.

  16. Evaluation of color-embedded wavelet image compression techniques

    NASA Astrophysics Data System (ADS)

    Saenz, Martha; Salama, Paul; Shen, Ke; Delp, Edward J., III

    1998-12-01

    Color embedded image compression is investigated by means of a set of core experiments that seek to evaluate the advantages of various color transformations, spatial orientation trees and the use of monochrome embedded coding schemes such as EZW and SPIHT. In order to take advantage of the interdependencies of the color components for a given color space, two new spatial orientation trees that relate frequency bands and color components are investigated.

  17. Retinal oxygen saturation evaluation by multi-spectral fundus imaging

    NASA Astrophysics Data System (ADS)

    Khoobehi, Bahram; Ning, Jinfeng; Puissegur, Elise; Bordeaux, Kimberly; Balasubramanian, Madhusudhanan; Beach, James

    2007-03-01

    Purpose: To develop a multi-spectral method to measure oxygen saturation of the retina in the human eye. Methods: Five Cynomolgus monkeys with normal eyes were anesthetized with intramuscular ketamine/xylazine and intravenous pentobarbital. Multi-spectral fundus imaging was performed in five monkeys with a commercial fundus camera equipped with a liquid crystal tuned filter in the illumination light path and a 16-bit digital camera. Recording parameters were controlled with software written specifically for the application. Seven images at successively longer oxygen-sensing wavelengths were recorded within 4 seconds. Individual images for each wavelength were captured in less than 100 msec of flash illumination. Slightly misaligned images of separate wavelengths due to slight eye motion were registered and corrected by translational and rotational image registration prior to analysis. Numerical values of relative oxygen saturation of retinal arteries and veins and the underlying tissue in between the artery/vein pairs were evaluated by an algorithm previously described, but which is now corrected for blood volume from averaged pixels (n > 1000). Color saturation maps were constructed by applying the algorithm at each image pixel using a Matlab script. Results: Both the numerical values of relative oxygen saturation and the saturation maps correspond to the physiological condition, that is, in a normal retina, the artery is more saturated than the tissue and the tissue is more saturated than the vein. With the multi-spectral fundus camera and proper registration of the multi-wavelength images, we were able to determine oxygen saturation in the primate retinal structures on a tolerable time scale which is applicable to human subjects. Conclusions: Seven wavelength multi-spectral imagery can be used to measure oxygen saturation in retinal artery, vein, and tissue (microcirculation). This technique is safe and can be used to monitor oxygen uptake in humans. This work

  18. Vergence and accommodation to multiple-image-plane stereoscopic displays: 'Real world' responses with practical image-plane separations?

    NASA Astrophysics Data System (ADS)

    MacKenzie, K. J.; Dickson, R. A.; Watt, S. J.

    2011-03-01

    Conventional stereoscopic displays present images on a single focal plane. The resulting mismatch between the stimuli to the eyes' focusing response (accommodation) and to convergence causes fatigue and poor stereo performance. One promising solution is to distribute image intensity across a number of relatively widely spaced image planes - a technique referred to as depth filtering. Previously, we found this elicits accurate, continuous monocular accommodation responses with image-plane separations as large as 1.1 Diopters, suggesting that a relatively small (i.e. practical) number of image planes is sufficient to eliminate vergence-accommodation conflicts over a large range of simulated distances. However, accommodation responses have been found to overshoot systematically when the same stimuli are viewed binocularly. Here, we examined the minimum image-plane spacing required for accurate accommodation to binocular depth-filtered images. We compared accommodation and vergence responses to step changes in depth for depth-filtered stimuli, using image-plane separations of 0.6-1.2 D, and equivalent real stimuli. Accommodation responses to real and depth-filtered stimuli were equivalent for image-plane separations of ~0.6-0.9 D, but inaccurate thereafter. We conclude that depth filtering can be used to precisely match accommodation and vergence demand in a practical stereoscopic display, using a relatively small number of image planes.

  19. [Imaging evaluation of renal function: principles and limitations].

    PubMed

    Vivier, P-H; Dolores, M; Le Cloirec, J; Beurdeley, M; Liard, A; Elbaz, F; Roset, J-B; Dacher, J-N

    2011-04-01

    The kidney performs multiple functions. Glomerular filtration is the most studied of these functions. In clinical practice, the surgical indication for patients with unilateral uropathy is frequently based on the split renal function as demonstrated by scintigraphy. MRI is not yet validated as a technique but nonetheless offers an interesting non-radiating alternative to achieve both morphological and functional renal evaluation. Recent pulse sequences such as diffusion, arterial spin labeling, and blood oxygenation dependent imaging may also provide additional information. CT and US remain of limited value for the evaluation of renal function.

  20. Multimodality Imaging Evaluation of an Uncommon Entity: Esophageal Heterotopic Pancreas

    PubMed Central

    Mack, Takman; Lowry, Debra; Carbone, Peter; Barbick, Brian; Kindelan, Joshua; Marks, Robert

    2014-01-01

    A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT), fluoroscopic upper gastrointestinal (GI) evaluation, endoscopic ultrasound (EUS), and positron emission tomography (PET) evaluation, revealing the presence of a heterogeneous esophageal mass. In light of imaging findings and clinical workup, the patient was ultimately referred for thorascopic surgery. Surgical findings and histology confirmed the diagnosis of esophageal heterotopic pancreas. PMID:24744946

  1. Prior image constrained compressed sensing: Implementation and performance evaluation

    PubMed Central

    Lauzier, Pascal Thériault; Tang, Jie; Chen, Guang-Hong

    2012-01-01

    Purpose: Prior image constrained compressed sensing (PICCS) is an image reconstruction framework which incorporates an often available prior image into the compressed sensing objective function. The images are reconstructed using an optimization procedure. In this paper, several alternative unconstrained minimization methods are used to implement PICCS. The purpose is to study and compare the performance of each implementation, as well as to evaluate the performance of the PICCS objective function with respect to image quality. Methods: Six different minimization methods are investigated with respect to convergence speed and reconstruction accuracy. These minimization methods include the steepest descent (SD) method and the conjugate gradient (CG) method. These algorithms require a line search to be performed. Thus, for each minimization algorithm, two line searching algorithms are evaluated: a backtracking (BT) line search and a fast Newton-Raphson (NR) line search. The relative root mean square error is used to evaluate the reconstruction accuracy. The algorithm that offers the best convergence speed is used to study the performance of PICCS with respect to the prior image parameter α and the data consistency parameter λ. PICCS is studied in terms of reconstruction accuracy, low-contrast spatial resolution, and noise characteristics. A numerical phantom was simulated and an animal model was scanned using a multirow detector computed tomography (CT) scanner to yield the projection datasets used in this study. Results: For λ within a broad range, the CG method with Fletcher-Reeves formula and NR line search offers the fastest convergence for an equal level of reconstruction accuracy. Using this minimization method, the reconstruction accuracy of PICCS was studied with respect to variations in α and λ. When the number of view angles is varied between 107, 80, 64, 40, 20, and 16, the relative root mean square error reaches a minimum value for α ≈ 0.5. For

  2. Noise evaluation of Compton camera imaging for proton therapy.

    PubMed

    Ortega, P G; Torres-Espallardo, I; Cerutti, F; Ferrari, A; Gillam, J E; Lacasta, C; Llosá, G; Oliver, J F; Sala, P R; Solevi, P; Rafecas, M

    2015-03-07

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  3. Noise evaluation of Compton camera imaging for proton therapy

    NASA Astrophysics Data System (ADS)

    Ortega, P. G.; Torres-Espallardo, I.; Cerutti, F.; Ferrari, A.; Gillam, J. E.; Lacasta, C.; Llosá, G.; Oliver, J. F.; Sala, P. R.; Solevi, P.; Rafecas, M.

    2015-02-01

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  4. Breast Cancer Subtype Influences the Accuracy of Predicting Pathologic Response by Imaging and Clinical Breast Exam After Neoadjuvant Chemotherapy.

    PubMed

    Waldrep, Ashley R; Avery, Eric J; Rose, Ferrill F; Midathada, Madhu V; Tilford, Joni A; Kolberg, Hans-Christian; Hutchins, Mark R

    2016-10-01

    Clinical response evaluation after neoadjuvant chemotherapy (NACT) for breast cancer could include various imaging methods, as well as clinical breast exam (CBE). We assessed the accuracy of CBE and imaging to predict pathologic response after NACT administration according to breast cancer subtype. This retrospective cohort study included 84 patients with records of NACT and subsequent primary breast surgery from 2003-2013. Patients were divided into 4 breast cancer subtypes according to hormone receptor (HR) status and human epidermal growth factor receptor-2 (HER2) status. Negative predictive value (NPV), false-negative rate (FNR), false-positive rate (FPR) and positive predictive value (PPV) were calculated for CBE and imaging post-NACT and prior to breast cancer surgery. NPV, FNR, FPR and PPV varied by breast cancer subtype and clinical response evaluation method. Imaging resulted in a higher NPV and a lower FNR than CBE among the entire cohort. There was a lower FPR with CBE. Clinical response evaluation by CBE was highly accurate for predicting pathologic residual disease in HR+ tumors (CBE PPV: 95.5% in HR+HER2-, 100.0% in HR+HER2+). In triple-negative breast cancer (TNBC), the imaging NPV was 100% and the imaging FNR was 0%. The use of imaging in HR+ tumors post-NACT may provide little to no additional value that is not already garnered by performance of a CBE. For TNBC, imaging may play a critical role in the prediction of pathologic complete response (pCR) post-NACT. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  5. Automation of contact lens fitting evaluation by digital image processing

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.; Barros, Rui; Franco, Sandra B.

    1997-08-01

    Contact lens' fitting evaluation is of critical importance in the contact lens' prescription process. For the correction of eye's refraction problems the use of contact lens' is very appealing to the user. However its prescription is far more demanding than the one of eye glasses. The fitting of a contact lens to a particular cornea must be carefully assessed in order to reduce possible user's physical miscomfort or even medical situations.The traditional way of easily checking the fitting of a contact lens is to perform a fluorescein test. The simple visual evaluation of the 'smoothness' of the color/brightness distribution of the fluorescence at the contact lens' location gives the optometrist an idea of the fitting's quality. We suggested the automation of the process simply by the substitution of the optometrist's eye by a CCD camera, and the use of appropriated simple image processing techniques. The setup and the digitalization and processing routines will be described in this communication. The processed images may then be directly analyzed by the optometrist in a faster, easier and more efficient way. However, it is also possible to perform an automated fitting evaluation by working out the information given by the image's intensity histograms for the green and blue RGB' channels.

  6. Automation of contact lens' fitting evaluation by digital image processing

    NASA Astrophysics Data System (ADS)

    da Cunha Martins Costa, M.; Barros, Rui; Franco, Sandra B.

    1997-10-01

    Contact lens' fitting evaluation is of critical importance in the contact lens' prescription process. For the correction of eye's refraction problems the use of contact lens' is very appealing to the user. However its prescription is far more demanding than the one of eye glasses. The fitting of a contact lens to a particular cornea must be carefully assessed in order to reduce possible user's physical miscomfort or even medical situations.The traditional way of easily checking the fitting of a contact lens is to perform a fluorescein test. The simple visual evaluation of the 'smoothness' of the color/brightness distribution of the fluorescence at the contact lens' location gives the optometrist an idea of the fitting's quality. We suggested the automation of the process simply by the substitution of the optometrist's eye by a CCD camera, and the use of appropriated simple image processing techniques. The setup and the digitalization and processing routines will be described in this communication. The processed images may then be directly analyzed by the optometrist in a faster, easier and more efficient way. However, it is also possible to perform an automated fitting evaluation by working out the information given by the image's intensity histograms for the green and blue RGB' channels.

  7. Beef assessments using functional magnetic resonance imaging and sensory evaluation.

    PubMed

    Tapp, W N; Davis, T H; Paniukov, D; Brooks, J C; Brashears, M M; Miller, M F

    2017-04-01

    Functional magnetic resonance imaging (fMRI) has been used to unveil how some foods and basic rewards are processed in the human brain. This study evaluated how resting state functional connectivity in regions of the human brain changed after differing qualities of beef steaks were consumed. Functional images of participants (n=8) were collected after eating high or low quality beef steaks on separate days, after consumption a sensory ballot was administered to evaluate consumers' perceptions of tenderness, juiciness, flavor, and overall liking. Imaging data showed that high quality steak samples resulted in greater functional connectivity to the striatum, medial orbitofrontal cortex, and insular cortex at various stages after consumption (P≤0.05). Furthermore, high quality steaks elicited higher sensory ballot scores for each palatability trait (P≤0.01). Together, these results suggest that resting state fMRI may be a useful tool for evaluating the neural process that follows positive sensory experiences such as the enjoyment of high quality beef steaks. Published by Elsevier Ltd.

  8. Study protocol: multi-parametric magnetic resonance imaging for therapeutic response prediction in rectal cancer.

    PubMed

    Pham, Trang Thanh; Liney, Gary; Wong, Karen; Rai, Robba; Lee, Mark; Moses, Daniel; Henderson, Christopher; Lin, Michael; Shin, Joo-Shik; Barton, Michael Bernard

    2017-07-04

    Response to neoadjuvant chemoradiotherapy (CRT) of rectal cancer is variable. Accurate imaging for prediction and early assessment of response would enable appropriate stratification of management to reduce treatment morbidity and improve therapeutic outcomes. Use of either diffusion weighted imaging (DWI) or dynamic contrast enhanced (DCE) imaging alone currently lacks sufficient sensitivity and specificity for clinical use to guide individualized treatment in rectal cancer. Multi-parametric MRI and analysis combining DWI and DCE may have potential to improve the accuracy of therapeutic response prediction and assessment. This protocol describes a prospective non-interventional single-arm clinical study. Patients with locally advanced rectal cancer undergoing preoperative CRT will prospectively undergo multi-parametric MRI pre-CRT, week 3 CRT, and post-CRT. The protocol consists of DWI using a read-out segmented sequence (RESOLVE), and DCE with pre-contrast T1-weighted (VIBE) scans for T1 calculation, followed by 60 phases at high temporal resolution (TWIST) after gadoversetamide injection. A 3-dimensional voxel-by-voxel technique will be used to produce colour-coded ADC and K(trans) histograms, and data evaluated in combination using scatter plots. MRI parameters will be correlated with surgical histopathology. Histopathology analysis will be standardized, with chemoradiotherapy response defined according to AJCC 7th Edition Tumour Regression Grade (TRG) criteria. Good response will be defined as TRG 0-1, and poor response will be defined as TRG 2-3. The combination of DWI and DCE can provide information on physiological tumour factors such as cellularity and perfusion that may affect radiotherapy response. If validated, multi-parametric MRI combining DWI and DCE can be used to stratify management in rectal cancer patients. Accurate imaging prediction of patients with a complete response to CRT would enable a 'watch and wait' approach, avoiding surgical morbidity

  9. Evaluation of image features and classification methods for Barrett's cancer detection using VLE imaging

    NASA Astrophysics Data System (ADS)

    Klomp, Sander; van der Sommen, Fons; Swager, Anne-Fré; Zinger, Svitlana; Schoon, Erik J.; Curvers, Wouter L.; Bergman, Jacques J.; de With, Peter H. N.

    2017-03-01

    Volumetric Laser Endomicroscopy (VLE) is a promising technique for the detection of early neoplasia in Barrett's Esophagus (BE). VLE generates hundreds of high resolution, grayscale, cross-sectional images of the esophagus. However, at present, classifying these images is a time consuming and cumbersome effort performed by an expert using a clinical prediction model. This paper explores the feasibility of using computer vision techniques to accurately predict the presence of dysplastic tissue in VLE BE images. Our contribution is threefold. First, a benchmarking is performed for widely applied machine learning techniques and feature extraction methods. Second, three new features based on the clinical detection model are proposed, having superior classification accuracy and speed, compared to earlier work. Third, we evaluate automated parameter tuning by applying simple grid search and feature selection methods. The results are evaluated on a clinically validated dataset of 30 dysplastic and 30 non-dysplastic VLE images. Optimal classification accuracy is obtained by applying a support vector machine and using our modified Haralick features and optimal image cropping, obtaining an area under the receiver operating characteristic of 0.95 compared to the clinical prediction model at 0.81. Optimal execution time is achieved using a proposed mean and median feature, which is extracted at least factor 2.5 faster than alternative features with comparable performance.

  10. Preclinical evaluation of a novel cyanine dye for tumor imaging with in vivo photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Temma, Takashi; Onoe, Satoru; Kanazaki, Kengo; Ono, Masahiro; Saji, Hideo

    2014-09-01

    Photoacoustic imaging (PA imaging or PAI) has shown great promise in the detection and monitoring of cancer. Although nanocarrier-based contrast agents have been studied for use in PAI, small molecule contrast agents are required due to their ease of preparation, cost-effectiveness, and low toxicity. Here, we evaluated the usefulness of a novel cyanine dye IC7-1-Bu as a PAI contrast agent without conjugated targeting moieties for in vivo tumor imaging in a mice model. Basic PA characteristics of IC7-1-Bu were compared with indocyanine green (ICG), a Food and Drug Administration approved dye, in an aqueous solution. We evaluated the tumor accumulation profile of IC7-1-Bu and ICG by in vivo fluorescence imaging. In vivo PAI was then performed with a photoacoustic tomography system 24 and 48 h after intravenous injection of IC7-1-Bu into tumor bearing mice. IC7-1-Bu showed about a 2.3-fold higher PA signal in aqueous solution compared with that of ICG. Unlike ICG, IC7-1-Bu showed high tumor fluorescence after intravenous injection. In vivo PAI provided a tumor to background PA signal ratio of approximately 2.5 after intravenous injection of IC7-1-Bu. These results indicate that IC7-1-Bu is a promising PAI contrast agent for cancer imaging without conjugation of targeting moieties.

  11. Evaluation of a Validation Method for MR Imaging-Based Motion Tracking Using Image Simulation

    NASA Astrophysics Data System (ADS)

    Moerman, Kevin M.; Kerskens, Christian M.; Lally, Caitríona; Flamini, Vittoria; Simms, Ciaran K.

    2009-12-01

    Magnetic Resonance (MR) imaging-based motion and deformation tracking techniques combined with finite element (FE) analysis are a powerful method for soft tissue constitutive model parameter identification. However, deriving deformation data from MR images is complex and generally requires validation. In this paper a validation method is presented based on a silicone gel phantom containing contrasting spherical markers. Tracking of these markers provides a direct measure of deformation. Validation of in vivo medical imaging techniques is often challenging due to the lack of appropriate reference data and the validation method may lack an appropriate reference. This paper evaluates a validation method using simulated MR image data. This provided an appropriate reference and allowed different error sources to be studied independently and allowed evaluation of the method for various signal-to-noise ratios (SNRs). The geometric bias error was between 0-[InlineEquation not available: see fulltext.] voxels while the noisy magnitude MR image simulations demonstrated errors under 0.1161 voxels (SNR: 5-35).

  12. Vibration-response imaging versus quantitative perfusion scintigraphy in the selection of patients for lung-resection surgery.

    PubMed

    Comce, Fatma; Bingol, Zuleyha; Kiyan, Esen; Tanju, Serhan; Toker, Alper; Cagatay, Pembe; Ece, Turhan

    2011-12-01

    In patients being considered for lung-resection surgery, quantitative perfusion scintigraphy is used to predict postoperative lung function and guide the determination of lung-resection candidacy. Vibration-response imaging has been proposed as a noninvasive, radiation-free, and simpler method to predict postoperative lung function. We compared vibration-response imaging to quantitative perfusion scintigraphy for predicting postoperative FEV(1) and diffusing capacity of the lung for carbon monoxide (D(LCO)). We enrolled 35 candidates for lung resection. Twenty-five patients had preoperative FEV(1) and D(LCO) MEASUREMENTS: The vibration-response-imaging measurements showed strong correlation with the quantitative-perfusion-scintigraphy measurements of predicted postoperative FEV(1)% (r = 0.87, P < .001), predicted postoperative FEV(1) (r = 0.90, P < .001), and predicted postoperative D(LCO)% (r = 0.90, P < .001). There was a correlation between predicted postoperative FEV(1) (% and L) measured via quantitative perfusion scintigraphy and the actual postoperative FEV(1) (% and L) (r = 0.47, P = .048, r = 0.73, P < .001). There was no difference between the vibration-response-imaging measurements and the actual postoperative measurements of predicted postoperative FEV(1) (% and L). There was a correlation between predicted postoperative FEV(1) (% and L) measured via vibration-response imaging and actual postoperative FEV(1) (% and L) (r = 0.52, P = .044, r = 0.79, P < .001). The mean differences between the predicted and actual postoperative FEV(1) values were 49 mL with vibration-response imaging, versus 230 mL with quantitative perfusion scintigraphy. Neither the vibration-response imaging nor the quantitative perfusion scintigraphy predicted postoperative D(LCO)% values agreed with the actual postoperative D(LCO)% values. Vibration-response imaging may be a good alternative to quantitative perfusion scintigraphy in evaluating lung-resection candidacy.

  13. Image Formation Interactive Lecture Demonstrations Using Personal Response Systems

    NASA Astrophysics Data System (ADS)

    Sokoloff, David R.

    2010-07-01

    The results of physics education research and the availability of microcomputer-based tools have led to the development over a number of years of the activity-based Physics Suite. Most of the Suite materials are designed for hands-on learning, for example student-oriented laboratory curricula like Real Time Physics. One reason for the success of these materials is that they encourage students to take an active role in their learning. More recently, personal response systems (clickers) have become available at many schools and universities around the world, and are used by many educators. This paper describes Suite materials designed to promote active learning in lecture—Interactive Lecture Demonstrations (ILDs)—that have been adapted for implementation with clickers. Image formation ILDs will be presented. Results of studies on the effectiveness of this approach will also be presented.

  14. Staged imaging pathway for the evaluation of pediatric appendicitis.

    PubMed

    Chien, Ming; Habis, Arie; Glynn, Loretto; O'Connor, Ann; Smith, Tracie L; Prendergast, Francis

    2016-07-01

    Despite significant radiation exposure involved with computed tomography (CT) in evaluation of pediatric appendicitis, its use is still widespread. The goal of this study was to assess the effect of a staged imaging pathway for appendicitis to significantly decrease CT use while maintaining diagnostic accuracy. Chart review was performed for patients evaluated for appendicitis over a 12-month period prior to and after pathway implementation. There was a significant decrease in CT use as initial imaging after implementation of the pathway; 87.1-13.4 % for evaluations positive for appendicitis (decrease 84.6 %, p < 0.0001) and 82.6-9.2 % for evaluations negative for appendicitis (decrease 88.9 %, p < 0.0001). Use of CT during any point in the evaluation decreased from 91.7 to 25.1 % (decrease 72.6 %, p < 0.0001). The negative appendectomy rate was similar; 5.4 % prior, 4.9 % post (p = 0.955). The missed appendicitis rate did not statistically change; 1.1 % prior, 3.7 % post (p = 0.523). The perforation rate was not statistically altered; 6.5 % prior; 9.8 % post (p = 0.421). 350 less patients underwent CT during the year following the pathway. The staged imaging pathway resulted in a marked decrease in children exposed to CT without compromising diagnostic accuracy.

  15. Binge drinking, depression, and electrocortical responses to emotional images.

    PubMed

    Connell, Arin M; Patton, Emily; McKillop, Hannah

    2015-09-01

    Binge drinking and depression are highly prevalent, associated with cognitive and affective impairments, and frequently co-occur. Yet little research has examined their joint relations with such processing impairment. The current study examines the relation between symptoms of depression, binge drinking, and the magnitude of early (early posterior negativity, EPN) and later (P3 and late positive potential, LPP) visual processing components of affectively negative, positive, and neutral visual stimuli. Participants included 42 undergraduate students recruited on the basis of depressive symptoms. Results of repeated measures analyses of variance (ANOVAs; Depression × Binge × Emotion × Laterality) showed that binge drinkers exhibited lower LPP amplitudes for negative images, compared with nonbinge drinkers, regardless of depression, consistent with motivational models of alcohol abuse. Otherwise, differences across depressed and nondepressed groups were largest among binge drinkers, including a pattern of stronger early attentional engagement (EPN) to negative and neutral images, but decreased later processing (P3 and LPP) across all emotional categories, consistent with a vigilance-avoidance response pattern. (c) 2015 APA, all rights reserved).

  16. Concurrent OCT imaging of stimulus evoked retinal neural activation and hemodynamic responses

    NASA Astrophysics Data System (ADS)

    Son, Taeyoon; Wang, Benquan; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2017-02-01

    It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation. These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases, which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye diseases.

  17. Vergence and accommodation to multiple-image-plane stereoscopic displays: ``real world'' responses with practical image-plane separations?

    NASA Astrophysics Data System (ADS)

    MacKenzie, Kevin J.; Dickson, Ruth A.; Watt, Simon J.

    2012-01-01

    Conventional stereoscopic displays present images on a single focal plane. The resulting mismatch between the stimuli to the eyes' focusing response (accommodation) and to convergence causes fatigue and poor stereo performance. One solution is to distribute image intensity across a number of widely spaced image planes--a technique referred to as depth filtering. Previously, we found this elicits accurate, continuous monocular accommodation responses with image-plane separations as large as 1.1 Diopters (D, the reciprocal of distance in meters), suggesting that a small number of image planes could eliminate vergence-accommodation conflicts over a large range of simulated distances. Evidence exists, however, of systematic differences between accommodation responses to binocular and monocular stimuli when the stimulus to accommodation is degraded, or at an incorrect distance. We examined the minimum image-plane spacing required for accurate accommodation to binocular depth-filtered images. We compared accommodation and vergence responses to changes in depth specified by depth filtering, using image-plane separations of 0.6 to 1.2 D, and equivalent real stimuli. Accommodation responses to real and depth-filtered stimuli were equivalent for image-plane separations of ~0.6 to 0.9 D, but differed thereafter. We conclude that depth filtering can be used to precisely match accommodation and vergence demand in a practical stereoscopic display.

  18. Evaluation of protection measures against laser dazzling for imaging sensors

    NASA Astrophysics Data System (ADS)

    Ritt, Gunnar; Eberle, Bernd

    2017-03-01

    We present our work regarding the evaluation of protection measures against laser dazzling for imaging devices. Different approaches for the evaluation of dazzled sensor images are investigated to estimate the loss of information due to the dazzle spot: (1) counting the number of overexposed pixels, (2) based on triangle orientation discrimination, and (3) using the structural similarity index. The evaluation approaches are applied on experimental data obtained with two different sensors hardened against laser dazzling. The hardening concept of the first sensor is based on the combination of a spatial light modulator and wavelength multiplexing. This protection concept allows spatially and spectrally resolved suppression of laser radiation within the sensor's field-of-view. The hardening concept of the second sensor utilizes the principle of "complementary bands." The optical setup resembles a common three-chip camera, with the difference that dedicated filters with steep edges replace the regular spectral band filters. Although this concept does not really represent a "protection measure," it allows the sensor to provide information even in laser dazzling situations. The data for the performance evaluation were acquired both in a laboratory setup using test charts comprising triangles of different size and orientation as well as in field trials.

  19. New performance evaluation models for character detection in images

    NASA Astrophysics Data System (ADS)

    Wang, YanWei; Ding, XiaoQing; Liu, ChangSong; Wang, Kongqiao

    2010-02-01

    Detection of characters regions is a meaningful research work for both highlighting region of interest and recognition for further information processing. A lot of researches have been performed on character localization and extraction and this leads to the great needs of performance evaluation scheme to inspect detection algorithms. In this paper, two probability models are established to accomplish evaluation tasks for different applications respectively. For highlighting region of interest, a Gaussian probability model, which simulates the property of a low-pass Gaussian filter of human vision system (HVS), was constructed to allocate different weights to different character parts. It reveals the greatest potential to describe the performance of detectors, especially, when the result detected is an incomplete character, where other methods cannot effectively work. For the recognition destination, we also introduced a weighted probability model to give an appropriate description for the contribution of detection results to final recognition results. The validity of performance evaluation models proposed in this paper are proved by experiments on web images and natural scene images. These models proposed in this paper may also be able to be applied in evaluating algorithms of locating other objects, like face detection and more wide experiments need to be done to examine the assumption.

  20. Calibration of the linear response range of x-ray imaging plates and their reader based on image grayscale values.

    PubMed

    Ren, Kuan; Xu, Tao; Zheng, Jianhua; Dong, Jianjun; Wei, Minxi; Li, Chaoguang; Cao, Zhurong; Du, Huabing; Yan, Ji; Yang, Guohong; Yi, Rongqing; Zhang, Jiyan; Huang, Tianxuan; Liu, Shenye; Wang, Feng; Yang, Zhiwen; Li, Jin; Chen, Yaohua; Lan, Ke; Ren, Guoli; Liu, Jie; Ding, Yongkun; Jiang, Shaoen

    2017-08-01

    X-ray imaging plates are one of the most important X-ray imaging detectors and are widely used in inertial-confinement fusion experiments. However, their linear response range, which is the foundation of their quantitative data analysis, has not been sufficiently deeply investigated. In this work, we develop an X-ray fluorescer calibration system and carefully explore the linear response range of X-ray imaging plates. For the first time, nearly the entire grayscale range of the X-ray imaging plate linear response-7819-64 879 in the range of 0-65 535-has been observed. Further, we discuss the uncertainties involved in the calibration process. This work demonstrates the excellent linear response qualities of X-ray imaging plates and provides a significant foundation for expanding their quantitative applied range.

  1. Evaluating an image-fusion algorithm with synthetic-image-generation tools

    NASA Astrophysics Data System (ADS)

    Gross, Harry N.; Schott, John R.

    1996-06-01

    An algorithm that combines spectral mixing and nonlinear optimization is used to fuse multiresolution images. Image fusion merges images of different spatial and spectral resolutions to create a high spatial resolution multispectral combination. High spectral resolution allows identification of materials in the scene, while high spatial resolution locates those materials. In this algorithm, conventional spectral mixing estimates the percentage of each material (called endmembers) within each low resolution pixel. Three spectral mixing models are compared; unconstrained, partially constrained, and fully constrained. In the partially constrained application, the endmember fractions are required to sum to one. In the fully constrained application, all fractions are additionally required to lie between zero and one. While negative fractions seem inappropriate, they can arise from random spectral realizations of the materials. In the second part of the algorithm, the low resolution fractions are used as inputs to a constrained nonlinear optimization that calculates the endmember fractions for the high resolution pixels. The constraints mirror the low resolution constraints and maintain consistency with the low resolution fraction results. The algorithm can use one or more higher resolution sharpening images to locate the endmembers to high spatial accuracy. The algorithm was evaluated with synthetic image generation (SIG) tools. A SIG developed image can be used to control the various error sources that are likely to impair the algorithm performance. These error sources include atmospheric effects, mismodeled spectral endmembers, and variability in topography and illumination. By controlling the introduction of these errors, the robustness of the algorithm can be studied and improved upon. The motivation for this research is to take advantage of the next generation of multi/hyperspectral sensors. Although the hyperspectral images will be of modest to low resolution

  2. Use of molecular imaging to quantify response to IKK-2 inhibitor treatment in murine arthritis.

    PubMed

    Izmailova, Elena S; Paz, Nancy; Alencar, Herlen; Chun, Miyoung; Schopf, Lisa; Hepperle, Michael; Lane, Joan H; Harriman, Geraldine; Xu, Yajun; Ocain, Timothy; Weissleder, Ralph; Mahmood, Umar; Healy, Aileen M; Jaffee, Bruce

    2007-01-01

    The NF-kappaB signaling pathway promotes the immune response in rheumatoid arthritis (RA) and in rodent models of RA. NF-kappaB activity is regulated by the IKK-2 kinase during inflammatory responses. To elucidate how IKK-2 inhibition suppresses disease development, we used a combination of in vivo imaging, transcription profiling, and histopathology technologies to study mice with antibody-induced arthritis. ML120B, a potent, small molecule inhibitor of IKK-2, was administered to arthritic animals, and disease activity was monitored. NF-kappaB activity in diseased joints was quantified by in vivo imaging. Quantitative reverse transcriptase-polymerase chain reaction was used to evaluate gene expression in joints. Protease-activated near-infrared fluorescence (NIRF) in vivo imaging was applied to assess the amounts of active proteases in the joints. Oral administration of ML120B suppressed both clinical and histopathologic manifestations of disease. In vivo imaging demonstrated that NF-kappaB activity in inflamed arthritic paws was inhibited by ML120B, resulting in significant suppression of multiple genes in the NF-kappaB pathway, i.e., KC, epithelial neutrophil-activating peptide 78, JE, intercellular adhesion molecule 1, CD3, CD68, tumor necrosis factor alpha, interleukin-1beta, interleukin-6, inducible nitric oxide synthase, cyclooxygenase 2, matrix metalloproteinase 3, cathepsin B, and cathepsin K. NIRF in vivo imaging demonstrated that ML120B treatment dramatically reduced the amount of active proteases in the joints. Our data demonstrate that IKK-2 inhibition in the murine model of antibody-induced arthritis suppresses both inflammation and joint destruction. In addition, this study highlights how gene expression profiling can facilitate the identification of surrogate biomarkers of disease activity and treatment response in an experimental model of arthritis.

  3. Utility of magnetic resonance imaging in the evaluation of left ventricular thickening.

    PubMed

    Fulton, Nicholas; Rajiah, Prabhakar

    2017-04-01

    Left ventricular (LV) thickening can be due to hypertrophy (concentric, asymmetric, eccentric) or remodelling (concentric or asymmetric). Pathological thickening may be caused by pressure overload, volume overload, infiltrative disorders, hypertrophic cardiomyopathy, athlete's heart or neoplastic infiltration. Magnetic resonance imaging (MRI) plays an important role in the comprehensive evaluation of LV thickening, including: establishing diagnosis, determining LV geometry, establishing aetiology, quantification, identifying prognostic factors, serial follow-up and treatment response. In this article, we review the aetiologies and pathophysiology of LV thickening, and demonstrate the comprehensive role of MRI in the evaluation of LV thickening.

  4. Evaluation of a large format image tube camera for the shuttle sortie mission

    NASA Technical Reports Server (NTRS)

    Tifft, W. C.

    1976-01-01

    A large format image tube camera of a type under consideration for use on the Space Shuttle Sortie Missions is evaluated. The evaluation covers the following subjects: (1) resolving power of the system (2) geometrical characteristics of the system (distortion etc.) (3) shear characteristics of the fiber optic coupling (4) background effects in the tube (5) uniformity of response of the tube (as a function of wavelength) (6) detective quantum efficiency of the system (7) astronomical applications of the system. It must be noted that many of these characteristics are quantitatively unique to the particular tube under discussion and serve primarily to suggest what is possible with this type of tube.

  5. Development of Novel Technetium-99m-Labeled Steroids as Estrogen-Responsive Breast Cancer Imaging Agents

    DTIC Science & Technology

    2007-06-01

    CONTRACT NUMBER Development of Novel Technetium -99m-Labeled Steroids as Estrogen-Responsive Breast Cancer Imaging Agents 5b. GRANT NUMBER...preparation and evaluation of new technetium -99m labeled compounds via utilization of their rhenium surrogates. An initial series of rhenium tricarbonyl

  6. Automation of immunohistochemical evaluation in breast cancer using image analysis

    PubMed Central

    Prasad, Keerthana; Tiwari, Avani; Ilanthodi, Sandhya; Prabhu, Gopalakrishna; Pai, Muktha

    2011-01-01

    AIM: To automate breast cancer diagnosis and to study the inter-observer and intra-observer variations in the manual evaluations. METHODS: Breast tissue specimens from sixty cases were stained separately for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2/neu). All cases were assessed by manual grading as well as image analysis. The manual grading was performed by an experienced expert pathologist. To study inter-observer and intra-observer variations, we obtained readings from another pathologist as the second observer from a different laboratory who has a little less experience than the first observer. We also took a second reading from the second observer to study intra-observer variations. Image analysis was carried out using in-house developed software (TissueQuant). A comparison of the results from image analysis and manual scoring of ER, PR and HER-2/neu was also carried out. RESULTS: The performance of the automated analysis in the case of ER, PR and HER-2/neu expressions was compared with the manual evaluations. The performance of the automated system was found to correlate well with the manual evaluations. The inter-observer variations were measured using Spearman correlation coefficient r and 95% confidence interval. In the case of ER expression, Spearman correlation r = 0.53, in the case of PR expression, r = 0.63, and in the case of HER-2/neu expression, r = 0.68. Similarly, intra-observer variations were also measured. In the case of ER, PR and HER-2/neu expressions, r = 0.46, 0.66 and 0.70, respectively. CONCLUSION: The automation of breast cancer diagnosis from immunohistochemically stained specimens is very useful for providing objective and repeatable evaluations. PMID:21611095

  7. A new method of skin erythrosis evaluation in digital images.

    PubMed

    Mezzana, P; Anniboletti, T; Curinga, G; Onesti, M G

    2007-01-01

    In the clinical field, reproducible and comparable assessments of skin color are needed for objective evaluation of lesions and efficacy of treatments. In order to provide objective, quantitative color information in skin lesions, devices such as reflectance spectrophotometer and reflectance colorimeter have been successfully used during the past decade, though they are too expensive and technically complex to be handled in routine clinical situations. Reflectance skin color measurements require direct contact of the probe with the skin, and the compression significantly influences readings. Color measurements obtained from digitized images have been proposed as a simple and cost-effective way to evaluate skin color and promote efficacy of treatments. The disadvantage is its direct and close relation to the ambient light: even if an accurate control of subject illumination is provided, readings vary between different laboratories. We propose a standard system for computerized color image analysis of skin erythrosis modification after Intense Pulsed Light (IPL) treatments, making it possible to compare readings taken by different observers in different environmental light conditions. The goal of our study is the introduction of fixed color internal controls in digital imaging in order to calculate a normalization factor of measurements, resulting not in a method of absolute quantification of erythema or erythrosis but in a method that provides the possibility of translation and comparison of the red values between systems in different environmental conditions. Between December 2004 and May 2005 we evaluated 30 patients at the Department of Plastic and Reconstructive Surgery at the University "La Sapienza" of Rome. Three points of standard colored paper (Red Green Blue) were applied with a plastic pattern (standard intersection lines) and white point in non involved area for skin control. For every patient we took a series of pictures pre-treatment and after a

  8. A Realistic Approach To Evaluating Digital Imaging Systems

    NASA Astrophysics Data System (ADS)

    Greinacher, C. F.; Bach, E.,; Muller, K.,; Patzelt, K.

    1984-06-01

    Current systems for the production of medical images and current development trends give a basis of experience for the design of a digital PACS including images and demographic data. Such a PACS must contain software and hardware concepts which permit the medical requirements, as presently understood, to be realized. As part of its research Siemens is designing and evaluating a hybrid network configuration which allows extensive flexibility and growth potential despite current limitations in available network bandwidth and storage capacity. As demand for digital data expands, additional installations can be added to the system. The modular concept permits incorporation of technological advances with minimal difficulty. The system allows different digital imaging modalities to communicate with a central data storage and processing system. Data display facilities both with and without manipulation capability are realized using high speed multi image storage devices. The human interface is designed to be ergono-metric, interactive, and user-friendly. Standardized, commercially available hardware has been included wherever possible to provide economical worldwide acceptance. Estimates of digital data per unit time under different conditions are presented and compared to the specifications of software and hardware elements both currently available and envisaged in the near future. Potential limitations of the design, as well as possible solutions incorporating expected technological developments, are discussed.

  9. Evaluation of muscle injury using magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, p<0.01); temporal changes in muscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  10. Changing trends of imaging in angle closure evaluation.

    PubMed

    Dorairaj, Syril; Tsai, James C; Grippo, Tomas M

    2012-01-01

    Primary angle closure glaucoma (PACG) is a significant cause of visual disability worldwide. It predominantly affects the Eastern and South Asian population of the world. Early detection of anatomically narrow angles is important, and the subsequent prevention of visual loss from PACG depends on an accurate assessment of the anterior chamber angle (ACA). Gonioscopy has given way to modern day imaging technologies such as ultrasound biomicroscopy (UBM) and more recently, anterior segment optical coherence tomography (AS-OCT). Ultrasound biomicroscopy provides objective, high-resolution images of anterior segment anatomy, including the cornea, iris, anterior chamber, anterior chamber angle, and ciliary body. Optical coherence tomography (OCT) is a noncontact optical signal acquisition and processing device that provides magnified, high-resolution cross-sectional images of ocular tissues. Recent technological advances towards three-dimensional visualization broadened the scope of AS-OCT in ophthalmologic evaluation. Optical coherence tomography systems use low-coherence, near-infrared light to provide detailed images of anterior segment structures at resolutions exceeding that of UBM. This paper summarizes the clinical application of UBM and OCT for assessment of anterior segment in glaucoma.

  11. Automatic evaluation of skin histopathological images for melanocytic features

    NASA Astrophysics Data System (ADS)

    Koosha, Mohaddeseh; Hoseini Alinodehi, S. Pourya; Nicolescu, Mircea; Safaei Naraghi, Zahra

    2017-03-01

    Successfully detecting melanocyte cells in the skin epidermis has great significance in skin histopathology. Because of the existence of cells with similar appearance to melanocytes in hematoxylin and eosin (HE) images of the epidermis, detecting melanocytes becomes a challenging task. This paper proposes a novel technique for the detection of melanocytes in HE images of the epidermis, based on the melanocyte color features, in the HSI color domain. Initially, an effective soft morphological filter is applied to the HE images in the HSI color domain to remove noise. Then a novel threshold-based technique is applied to distinguish the candidate melanocytes' nuclei. Similarly, the method is applied to find the candidate surrounding halos of the melanocytes. The candidate nuclei are associated with their surrounding halos using the suggested logical and statistical inferences. Finally, a fuzzy inference system is proposed, based on the HSI color information of a typical melanocyte in the epidermis, to calculate the similarity ratio of each candidate cell to a melanocyte. As our review on the literature shows, this is the first method evaluating epidermis cells for melanocyte similarity ratio. Experimental results on various images with different zooming factors show that the proposed method improves the results of previous works.

  12. Evaluation of muscle injury using magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, p<0.01); temporal changes in muscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  13. 40 CFR 265.93 - Preparation, evaluation, and response.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Preparation, evaluation, and response. 265.93 Section 265.93 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Ground-Water Monitoring § 265.93 Preparation, evaluation, and...

  14. Evaluation Responsibility and Leadership in the Face of Failing Democracies

    ERIC Educational Resources Information Center

    McKegg, Kate

    2013-01-01

    In a world faced with unprecedented rising levels of inequality and injustice, is there a responsibility for our evaluation organizations to take on a leadership role in promoting inclusive, evaluative dialog and deliberation about the state of our democracies in relation to key democratic principles and ideals? In this forum, I question whether…

  15. Evaluating color performance of whole-slide imaging devices by multispectral-imaging of biological tissues

    NASA Astrophysics Data System (ADS)

    Saleheen, Firdous; Badano, Aldo; Cheng, Wei-Chung

    2017-03-01

    The color reproducibility of two whole-slide imaging (WSI) devices was evaluated with biological tissue slides. Three tissue slides (human colon, skin, and kidney) were used to test a modern and a legacy WSI devices. The color truth of the tissue slides was obtained using a multispectral imaging system. The output WSI images were compared with the color truth to calculate the color difference for each pixel. A psychophysical experiment was also conducted to measure the perceptual color reproducibility (PCR) of the same slides with four subjects. The experiment results show that the mean color differences of the modern, legacy, and monochrome WSI devices are 10.94+/-4.19, 22.35+/-8.99, and 42.74+/-2.96 ▵E00, while their mean PCRs are 70.35+/-7.64%, 23.06+/-14.68%, and 0.91+/-1.01%, respectively.

  16. Evaluation of effector cell fate and function by in vivo bioluminescence imaging.

    PubMed

    Edinger, Matthias; Hoffmann, Petra; Contag, Christopher H; Negrin, Robert S

    2003-10-01

    The effector functions of immune cells have typically been examined using assays that require sampling of tissues or cells to reveal specific aspects of an immune response (e.g., antigen-specificity, cytokine expression or killing of target cells). The outcome of an immune response in vivo, however, is not solely determined by a single effector function of a specific cell population, but is the result of numerous cellular and molecular interactions that occur in the complex environment of intact organ systems. These interactions influence survival, migration, and activation, as well as final effector function of a given population of cells. Efforts to reveal the cellular and molecular basis of biological processes have resulted in a number of technologies that combine molecular biology and imaging sciences that are collectively termed as Molecular Imaging. This emerging field has developed to reveal functional aspects of cells, genes, and proteins in real time in living animals and humans and embraces multiple modalities, including established clinical imaging methods such as magnetic resonance imaging, single photon emission computed tomography, and positron emission tomography, as well as novel methodologies specifically designed for research animals. Here, we highlight one of the newer modalities, in vivo bioluminescence imaging, as a method for evaluating effector T cell proliferation, migration, and function in model systems of malignant and non-malignant diseases.

  17. A comparison of five standard methods for evaluating image intensity uniformity in partially parallel imaging MRI.

    PubMed

    Goerner, Frank L; Duong, Timothy; Stafford, R Jason; Clarke, Geoffrey D

    2013-08-01

    To investigate the utility of five different standard measurement methods for determining image uniformity for partially parallel imaging (PPI) acquisitions in terms of consistency across a variety of pulse sequences and reconstruction strategies. Images were produced with a phantom using a 12-channel head matrix coil in a 3T MRI system (TIM TRIO, Siemens Medical Solutions, Erlangen, Germany). Images produced using echo-planar, fast spin echo, gradient echo, and balanced steady state free precession pulse sequences were evaluated. Two different PPI reconstruction methods were investigated, generalized autocalibrating partially parallel acquisition algorithm (GRAPPA) and modified sensitivity-encoding (mSENSE) with acceleration factors (R) of 2, 3, and 4. Additionally images were acquired with conventional, two-dimensional Fourier imaging methods (R=1). Five measurement methods of uniformity, recommended by the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) were considered. The methods investigated were (1) an ACR method and a (2) NEMA method for calculating the peak deviation nonuniformity, (3) a modification of a NEMA method used to produce a gray scale uniformity map, (4) determining the normalized absolute average deviation uniformity, and (5) a NEMA method that focused on 17 areas of the image to measure uniformity. Changes in uniformity as a function of reconstruction method at the same R-value were also investigated. Two-way analysis of variance (ANOVA) was used to determine whether R-value or reconstruction method had a greater influence on signal intensity uniformity measurements for partially parallel MRI. Two of the methods studied had consistently negative slopes when signal intensity uniformity was plotted against R-value. The results obtained comparing mSENSE against GRAPPA found no consistent difference between GRAPPA and mSENSE with regard to signal intensity uniformity. The results of the two

  18. Evaluation schemes for video and image anomaly detection algorithms

    NASA Astrophysics Data System (ADS)

    Parameswaran, Shibin; Harguess, Josh; Barngrover, Christopher; Shafer, Scott; Reese, Michael

    2016-05-01

    Video anomaly detection is a critical research area in computer vision. It is a natural first step before applying object recognition algorithms. There are many algorithms that detect anomalies (outliers) in videos and images that have been introduced in recent years. However, these algorithms behave and perform differently based on differences in domains and tasks to which they are subjected. In order to better understand the strengths and weaknesses of outlier algorithms and their applicability in a particular domain/task of interest, it is important to measure and quantify their performance using appropriate evaluation metrics. There are many evaluation metrics that have been used in the literature such as precision curves, precision-recall curves, and receiver operating characteristic (ROC) curves. In order to construct these different metrics, it is also important to choose an appropriate evaluation scheme that decides when a proposed detection is considered a true or a false detection. Choosing the right evaluation metric and the right scheme is very critical since the choice can introduce positive or negative bias in the measuring criterion and may favor (or work against) a particular algorithm or task. In this paper, we review evaluation metrics and popular evaluation schemes that are used to measure the performance of anomaly detection algorithms on videos and imagery with one or more anomalies. We analyze the biases introduced by these by measuring the performance of an existing anomaly detection algorithm.

  19. Evaluation of diffuse technologies: the case of digital imaging networks.

    PubMed

    Keen, J; Bryan, S; Muris, N; Weatherburn, G; Buxton, M

    1995-12-01

    There have been significant developments in recent years in the methodologies and methods for the evaluation of a wide range of health technologies. There remain, though, many technologies which are difficult to evaluate. Often the difficulty stems from the complexity of the technologies themselves, which are in effect hybrids, comprising combinations of several distinct elements. In this paper these are termed 'diffuse' technologies, because the different elements exert different costs and effects, often across several different services. Computer networks are one, increasingly important, example of such technologies in health care. While it is possible to evaluate individual elements of such technologies, it is not clear how to evaluate the technology as a whole, where the whole may be greater (or less) than the sum of the parts. The paper outlines a seven-stage framework for the evaluation of diffuse technologies. The general principles of evaluation are illustrated using the example of picture archiving and communication systems (PACS), which are computer systems designed to capture, store and distribute electronic radiological images within a hospital.

  20. An evaluation for speckle filters of SAR images

    NASA Astrophysics Data System (ADS)

    Wang, Xiaojun; Sun, Hong

    2005-10-01

    A new evaluation method is proposed for single polarimetric speckle filters of Synthetic Aperture Radar (SAR) images, including two steps: measurement and aggregating multicriteria. In accordance with three properties of a good speckle filter: speckle reduction, feature preservation and radiometric preservation, six measures are selected: Equivalent Number of Looks (ENL), Target-to clutter Ratio, Radiometric Loss, Bias of Mean Value, Bias of Spatial Resolution, Bias of Peak Sidelobe Ratio, where the last two criteria are firstly addressed in this presentation. In multicriteria decision making, Ordered Weighted Averaging (OWA) operator is used to aggregate the performance preference matrix induced by measures. The experiment result of real and synthetic SAR images for five speckle filters conforms to that of visual comparison.

  1. Quantitative Evaluation of Strain Near Tooth Fillet by Image Processing

    NASA Astrophysics Data System (ADS)

    Masuyama, Tomoya; Yoshiizumi, Satoshi; Inoue, Katsumi

    The accurate measurement of strain and stress in a tooth is important for the reliable evaluation of the strength or life of gears. In this research, a strain measurement method which is based on image processing is applied to the analysis of strain near the tooth fillet. The loaded tooth is photographed using a CCD camera and stored as a digital image. The displacement of the point in the tooth flank is tracked by the cross-correlation method, and then, the strain is calculated. The interrogation window size of the correlation method and the overlap amount affect the accuracy and resolution. In the case of measurements at structures with complicated profiles such as fillets, the interrogation window maintains a large size and the overlap amount should be large. The surface condition also affects the accuracy. The white painted surface with a small black particle is suitable for measurement.

  2. Horizontal Long Axis Imaging Plane for Evaluation of Right Ventricular Function on Cardiac Magnetic Resonance Imaging

    PubMed Central

    Chaturvedi, Abhishek; Whitnah, Joseph; Maki, Jeffrey H; Baran, Timothy; Mitsumori, Lee M

    2016-01-01

    Purpose: The purpose of this study was to evaluate a horizontal long axis (HLA) magnetic resonance imaging (MRI) plane aligned to the long axis of the right ventricular (RV) cavity for functional analysis by comparing the measurement variability and time required for the analysis with that using a short-axis (SAX) image orientation. Materials and Methods: Thirty-four cardiac MRI exams with cine balanced steady-state free precession image stacks in both the SAX and the HLA of the RV (RHLA) were evaluated. Two reviewers independently traced RV endocardial borders on each image of the cine stacks. The time required to complete each set of traces was recorded, and the RV end-diastolic volume, end-systolic volume, and ejection fraction were calculated. Analysis times and RV measurements were compared between the two orientations. Results: Analysis time for each reviewer was significantly shorter for the RHLA stack (reviewer 1 = 6.4 ± 1.8 min, reviewer 2 = 6.0 ± 3.3 min) than for the SAX stack (7.5 ± 2.1 and 6.9 ± 3.6 min, respectively; P < 0.002). Bland–Altman analysis revealed lower mean differences, limits of agreement, and coefficients of variation for RV measurements obtained with the RHLA stack. Conclusions: RV functional analysis using a RHLA stack resulted in shorter analysis times and lower measurement variability than for a SAX stack orientation. PMID:28123842

  3. Evaluating the capability of time-of-flight cameras for accurately imaging a cyclically loaded beam

    NASA Astrophysics Data System (ADS)

    Lahamy, Hervé; Lichti, Derek; El-Badry, Mamdouh; Qi, Xiaojuan; Detchev, Ivan; Steward, Jeremy; Moravvej, Mohammad

    2015-05-01

    Time-of-flight cameras are used for diverse applications ranging from human-machine interfaces and gaming to robotics and earth topography. This paper aims at evaluating the capability of the Mesa Imaging SR4000 and the Microsoft Kinect 2.0 time-of-flight cameras for accurately imaging the top surface of a concrete beam subjected to fatigue loading in laboratory conditions. Whereas previous work has demonstrated the success of such sensors for measuring the response at point locations, the aim here is to measure the entire beam surface in support of the overall objective of evaluating the effectiveness of concrete beam reinforcement with steel fibre reinforced polymer sheets. After applying corrections for lens distortions to the data and differencing images over time to remove systematic errors due to internal scattering, the periodic deflections experienced by the beam have been estimated for the entire top surface of the beam and at witness plates attached. The results have been assessed by comparison with measurements from highly-accurate laser displacement transducers. This study concludes that both the Microsoft Kinect 2.0 and the Mesa Imaging SR4000s are capable of sensing a moving surface with sub-millimeter accuracy once the image distortions have been modeled and removed.

  4. CMOS Image Sensor and System for Imaging Hemodynamic Changes in Response to Deep Brain Stimulation.

    PubMed

    Zhang, Xiao; Noor, Muhammad S; McCracken, Clinton B; Kiss, Zelma H T; Yadid-Pecht, Orly; Murari, Kartikeya

    2016-06-01

    Deep brain stimulation (DBS) is a therapeutic intervention used for a variety of neurological and psychiatric disorders, but its mechanism of action is not well understood. It is known that DBS modulates neural activity which changes metabolic demands and thus the cerebral circulation state. However, it is unclear whether there are correlations between electrophysiological, hemodynamic and behavioral changes and whether they have any implications for clinical benefits. In order to investigate these questions, we present a miniaturized system for spectroscopic imaging of brain hemodynamics. The system consists of a 144 ×144, [Formula: see text] pixel pitch, high-sensitivity, analog-output CMOS imager fabricated in a standard 0.35 μm CMOS process, along with a miniaturized imaging system comprising illumination, focusing, analog-to-digital conversion and μSD card based data storage. This enables stand alone operation without a computer, nor electrical or fiberoptic tethers. To achieve high sensitivity, the pixel uses a capacitive transimpedance amplifier (CTIA). The nMOS transistors are in the pixel while pMOS transistors are column-parallel, resulting in a fill factor (FF) of 26%. Running at 60 fps and exposed to 470 nm light, the CMOS imager has a minimum detectable intensity of 2.3 nW/cm(2) , a maximum signal-to-noise ratio (SNR) of 49 dB at 2.45 μW/cm(2) leading to a dynamic range (DR) of 61 dB while consuming 167 μA from a 3.3 V supply. In anesthetized rats, the system was able to detect temporal, spatial and spectral hemodynamic changes in response to DBS.

  5. Feasibility of FAIR imaging for evaluating tumor perfusion.

    PubMed

    Cho, Jee-Hyun; Cho, Gyunggoo; Song, Youngkyu; Lee, Chulhyun; Park, Bum-Woo; Lee, Chang Kyung; Kim, Namkug; Park, Sung Bin; Kang, Jong Soon; Kang, Moo Rim; Kim, Hwan Mook; Kim, Young Ro; Cho, Kyoung-Sik; Kim, Jeong Kon

    2010-09-01

    To evaluate the feasibility of flow-sensitive alternating inversion recovery (FAIR) for measuring blood flow in tumor models. In eight mice tumor models, FAIR and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed. The reliability for measuring blood flow on FAIR was evaluated using the coefficient of variation of blood flow on psoas muscle. Three regions of interest (ROIs) were drawn in the peripheral, intermediate, and central portions within each tumor. The location of ROI was the same on FAIR and DCE-MR images. The correlation between the blood flow on FAIR and perfusion-related parameters on DCE-MRI was evaluated using the Pearson correlation coefficient. The coefficient of variation for measuring blood flow was 9.8%. Blood flow on FAIR showed a strong correlation with Kep (r = 0.77), percent relative enhancement (r = 0.73), and percent enhancement ratio (r = 0.81). The mean values of blood flow (mL/100 g/min) (358 vs. 207), Kep (sec(-) (1)) (7.46 vs. 1.31), percent relative enhancement (179% vs. 134%), and percent enhancement ratio (42% vs. 26%) were greater in the peripheral portion than in the central portion (P < 0.01). As blood flow measurement on FAIR is reliable and closely related with that on DCE-MR, FAIR is feasible for measuring tumor blood flow.

  6. Ultrasonic imaging for non-destructive evaluation of standing trees: effect of anisotropy on image reconstruction

    NASA Astrophysics Data System (ADS)

    Espinosa, Luis; Prieto, Flavio; Brancheriau, Loïc.

    2017-03-01

    Trees play a major ecological and sanitary role in modern cities. Nondestructive imaging methods allow to analyze the inner structures of trees, without altering their condition. In this study, we are interested on evaluating the influence of anisotropy condition in wood on the tomography image reconstruction using ultrasonic waves, by time-of-flight (TOF) estimation using the raytracing approach, a technique used particularly in the field of exploration seismography to simulate wave fronts in elastic media. Mechanical parameters from six wood species and one isotropic material were defined and their wave fronts and corresponding TOF values were obtained, using the proposed raytracing method. If the material presented anisotropy, the ray paths between the emitter and the receivers were not straight; therefore, curved rays were obtained for wood and the TOF measurements were affected. To obtain the tomographic image from the TOF measurements, the filtered back-projection algorithm was applied, a widely used technique in applications of straight ray tomography, but also commonly used in wood acoustic tomography. First, discs without inner defects for isotropic and wood materials (Spruce sample) were tested. Isotropic material resulted in a flat color image; for wood material, a gradient of velocities was obtained. After, centric and eccentric defects were tested, both for isotropic and orthotropic cases. From the results obtained for wood, when using a reconstruction algorithm intended for straight ray tomography, the images presented velocity variations from the border to the center that made difficult the discrimination of possible defects inside the samples, especially for eccentric cases.

  7. Quantitative imaging to evaluate malignant potential of IPMNs

    PubMed Central

    Hanania, Alexander N.; Bantis, Leonidas E.; Feng, Ziding; Wang, Huamin; Tamm, Eric P.; Katz, Matthew H.; Maitra, Anirban; Koay, Eugene J.

    2016-01-01

    Objective To investigate using quantitative imaging to assess the malignant potential of intraductal papillary mucinous neoplasms (IPMNs) in the pancreas. Background Pancreatic cysts are identified in over 2% of the population and a subset of these, including intraductal papillary mucinous neoplasms (IPMNs), represent pre-malignant lesions. Unfortunately, clinicians cannot accurately predict which of these lesions are likely to progress to pancreatic ductal adenocarcinoma (PDAC). Methods We investigated 360 imaging features within the domains of intensity, texture and shape using pancreatic protocol CT images in 53 patients diagnosed with IPMN (34 “high-grade” [HG] and 19 “low-grade” [LG]) who subsequently underwent surgical resection. We evaluated the performance of these features as well as the Fukuoka criteria for pancreatic cyst resection. Results In our cohort, the Fukuoka criteria had a false positive rate of 36%. We identified 14 imaging biomarkers within Gray-Level Co-Occurrence Matrix (GLCM) that predicted histopathological grade within cyst contours. The most predictive marker differentiated LG and HG lesions with an area under the curve (AUC) of .82 at a sensitivity of 85% and specificity of 68%. Using a cross-validated design, the best logistic regression yielded an AUC of 0.96 (σ = .05) at a sensitivity of 97% and specificity of 88%. Based on the principal component analysis, HG IPMNs demonstrated a pattern of separation from LG IPMNs. Conclusions HG IPMNs appear to have distinct imaging properties. Further validation of these findings may address a major clinical need in this population by identifying those most likely to benefit from surgical resection. PMID:27588410

  8. Vibration response imaging in idiopathic pulmonary fibrosis: a pilot study.

    PubMed

    Liu, Qing-Xia; Guan, Wei-Jie; Xie, Yan-Qing; An, Jia-Ying; Jiang, Mei; Zhu, Zheng; Guo, E; Yu, Xin-Xin; Liu, Wen-Ting; Gao, Yi; Zheng, Jin-Ping

    2014-07-01

    Vibration response imaging (VRI) is a novel imaging technique and little is known about its characteristics and diagnostic value in idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the features of VRI in subjects with IPF. We enrolled 23 subjects with IPF (42-74 y old) and 28 healthy subjects (42-72 y old). Subjects with IPF were diagnosed by lung biopsy and underwent VRI, spirometry, lung diffusion testing, and chest x-ray or computed tomography, which entailed assessment of the value of VRI indices. The total VRI score correlated statistically with single-breath carbon monoxide diffusing capacity percent predicted (r = -0.30, P = .04), but not with FVC percent predicted, FEV1 percent predicted, and FEV1/FVC (r = -0.27, -0.22, and 0.19; all P > .05). Compared with healthy subjects (17.9%), 20 subjects with IPF (86.96%, P < .01) presented with significantly increased crackles. The difference in quality lung data in all lung regions was unremarkable (all P > .05), except for the upper right and lower left lobes (P < .05). Overall, VRI parameters yielded acceptable assay sensitivity and specificity. Maximum energy frame was characterized by the highest diagnostic value (sensitivity, 1.00; specificity, 0.82), followed by presence of abundant crackles (sensitivity, 0.70; specificity, 0.96). Total VRI score was not a sensitive indicator of IPF, owing to low assay sensitivity (0.70) and specificity (0.64). VRI may be helpful to discriminate between IPF subjects and healthy individuals. Maximum energy frame and abundant crackles might serve as a diagnostic tool for IPF. Copyright © 2014 by Daedalus Enterprises.

  9. Quantification of UV-induced erythema and pigmentation using computer-assisted digital image evaluation.

    PubMed

    Coelho, Sergio G; Miller, Sharon A; Zmudzka, Barbara Z; Beer, Janusz Z

    2006-01-01

    Photography has been used in human skin research for some time. With the advent of digital photography in recent years, its use has increased. However, the focus has now turned from documentation to actual analysis and quantification of skin color changes. The advantages of digital photography outweigh any shortcomings as long as consistent, standardized procedures are followed and quality control is implemented. We present a simple procedure to standardize images and discuss a computer-assisted digital image evaluation (CADIE) technique to quantify skin color changes following UV exposure. The CADIE approach is illustrated with examples from two different studies on UV responses in human skin. Using the Commission Internationale de l'Eclairage L*a*b* color coordinate system in combination with a personal computer and image-editing software, we analyzed digital images obtained in these two studies. We demonstrate the feasibility of using digital photography for objective evaluation of UV erythema in different racial/ethnic groups and for measuring pigmentation changes caused by repeated exposures over a period of several weeks. Our results indicate how objective assessment using CADIE can be an adjunct to visual and optical observation in clinical and scientific evaluations.

  10. Digital imaging approaches for phenotyping whole plant nitrogen and phosphorus response in Brachypodium distachyon.

    PubMed

    Poiré, Richard; Chochois, Vincent; Sirault, Xavier R R; Vogel, John P; Watt, Michelle; Furbank, Robert T

    2014-08-01

    This work evaluates the phenotypic response of the model grass (Brachypodium distachyon (L.) P. Beauv.) to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. Reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight (R(2) > 0.92) and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response to nitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determination of genomic regions associated with superior nutrient use efficiency. © 2014 CSIRO Journal of Integrative Plant Biology © 2014 Institute of Botany, Chinese Academy of Sciences This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  11. Image quality evaluation of breast tomosynthesis with synchrotron radiation

    SciTech Connect

    Malliori, A.; Bliznakova, K.; Speller, R. D.; Horrocks, J. A.; Rigon, L.; Tromba, G.; Pallikarakis, N.

    2012-09-15

    Purpose: This study investigates the image quality of tomosynthesis slices obtained from several acquisition sets with synchrotron radiation using a breast phantom incorporating details that mimic various breast lesions, in a heterogeneous background. Methods: A complex Breast phantom (MAMMAX) with a heterogeneous background and thickness that corresponds to 4.5 cm compressed breast with an average composition of 50% adipose and 50% glandular tissue was assembled using two commercial phantoms. Projection images using acquisition arcs of 24 Degree-Sign , 32 Degree-Sign , 40 Degree-Sign , 48 Degree-Sign , and 56 Degree-Sign at incident energy of 17 keV were obtained from the phantom with the synchrotron radiation for medical physics beamline at ELETTRA Synchrotron Light Laboratory. The total mean glandular dose was set equal to 2.5 mGy. Tomograms were reconstructed with simple multiple projection algorithm (MPA) and filtered MPA. In the latter case, a median filter, a sinc filter, and a combination of those two filters were applied on the experimental data prior to MPA reconstruction. Visual inspection, contrast to noise ratio, contrast, and artifact spread function were the figures of merit used in the evaluation of the visualisation and detection of low- and high-contrast breast features, as a function of the reconstruction algorithm and acquisition arc. To study the benefits of using monochromatic beams, single projection images at incident energies ranging from 14 to 27 keV were acquired with the same phantom and weighted to synthesize polychromatic images at a typical incident x-ray spectrum with W target. Results: Filters were optimised to reconstruct features with different attenuation characteristics and dimensions. In the case of 6 mm low-contrast details, improved visual appearance as well as higher contrast to noise ratio and contrast values were observed for the two filtered MPA algorithms that exploit the sinc filter. These features are better visualized

  12. Image quality evaluation of breast tomosynthesis with synchrotron radiation.

    PubMed

    Malliori, A; Bliznakova, K; Speller, R D; Horrocks, J A; Rigon, L; Tromba, G; Pallikarakis, N

    2012-09-01

    This study investigates the image quality of tomosynthesis slices obtained from several acquisition sets with synchrotron radiation using a breast phantom incorporating details that mimic various breast lesions, in a heterogeneous background. A complex Breast phantom (MAMMAX) with a heterogeneous background and thickness that corresponds to 4.5 cm compressed breast with an average composition of 50% adipose and 50% glandular tissue was assembled using two commercial phantoms. Projection images using acquisition arcs of 24°, 32°, 40°, 48°, and 56° at incident energy of 17 keV were obtained from the phantom with the synchrotron radiation for medical physics beamline at ELETTRA Synchrotron Light Laboratory. The total mean glandular dose was set equal to 2.5 mGy. Tomograms were reconstructed with simple multiple projection algorithm (MPA) and filtered MPA. In the latter case, a median filter, a sinc filter, and a combination of those two filters were applied on the experimental data prior to MPA reconstruction. Visual inspection, contrast to noise ratio, contrast, and artifact spread function were the figures of merit used in the evaluation of the visualisation and detection of low- and high-contrast breast features, as a function of the reconstruction algorithm and acquisition arc. To study the benefits of using monochromatic beams, single projection images at incident energies ranging from 14 to 27 keV were acquired with the same phantom and weighted to synthesize polychromatic images at a typical incident x-ray spectrum with W target. Filters were optimised to reconstruct features with different attenuation characteristics and dimensions. In the case of 6 mm low-contrast details, improved visual appearance as well as higher contrast to noise ratio and contrast values were observed for the two filtered MPA algorithms that exploit the sinc filter. These features are better visualized at extended arc length, as the acquisition arc of 56° with 15 projection images

  13. Thoracic magnetic resonance imaging for the evaluation of pulmonary emphysema.

    PubMed

    Lee, Sang Min; Seo, Joon Beom; Hwang, Hye Jeon; Kim, Eun Young; Oh, Sang Young; Kim, Ji-Eun

    2013-05-01

    Pulmonary emphysema is a pathologic condition characterized by permanently enlarged airspaces distal to the terminal bronchiole with destruction of the alveolar walls. Functional information of the lungs is important to understand the pathophysiology of emphysema and that of chronic obstructive pulmonary disease. With the recent developments in magnetic resonance imaging (MRI) techniques, functional MRI with variable MR sequences can be used for the evaluation of different physiological and anatomic changes seen in cases of pulmonary emphysema. In this review article, we will focus on a brief description of each method, results of some of the most recent work, and the clinical application of such knowledge.

  14. Evaluation of Fiber Reinforced Cement Using Digital Image Correlation

    PubMed Central

    Melenka, Garrett W.; Carey, Jason P.

    2015-01-01

    The effect of short fiber reinforcements on the mechanical properties of cement has been examined using a splitting tensile – digital image correlation (DIC) measurement method. Three short fiber reinforcement materials have been used in this study: fiberglass, nylon, and polypropylene. The method outlined provides a simple experimental setup that can be used to evaluate the ultimate tensile strength of brittle materials as well as measure the full field strain across the surface of the splitting tensile test cylindrical specimen. Since the DIC measurement technique is a contact free measurement this method can be used to assess sample failure. PMID:26039590

  15. Evaluation of fiber reinforced cement using digital image correlation.

    PubMed

    Melenka, Garrett W; Carey, Jason P

    2015-01-01

    The effect of short fiber reinforcements on the mechanical properties of cement has been examined using a splitting tensile - digital image correlation (DIC) measurement method. Three short fiber reinforcement materials have been used in this study: fiberglass, nylon, and polypropylene. The method outlined provides a simple experimental setup that can be used to evaluate the ultimate tensile strength of brittle materials as well as measure the full field strain across the surface of the splitting tensile test cylindrical specimen. Since the DIC measurement technique is a contact free measurement this method can be used to assess sample failure.

  16. Calibration of the linear response range of x-ray imaging plates and their reader based on image grayscale values

    NASA Astrophysics Data System (ADS)

    Ren, Kuan; Xu, Tao; Zheng, Jianhua; Dong, Jianjun; Wei, Minxi; Li, Chaoguang; Cao, Zhurong; Du, Huabing; Yan, Ji; Yang, Guohong; Yi, Rongqing; Zhang, Jiyan; Huang, Tianxuan; Liu, Shenye; Wang, Feng; Yang, Zhiwen; Li, Jin; Chen, Yaohua; Lan, Ke; Ren, Guoli; Liu, Jie; Ding, Yongkun; Jiang, Shaoen

    2017-08-01

    X-ray imaging plates are one of the most important X-ray imaging detectors and are widely used in inertial-confinement fusion experiments. However, their linear response range, which is the foundation of their quantitative data analysis, has not been sufficiently deeply investigated. In this work, we develop an X-ray fluorescer calibration system and carefully explore the linear response range of X-ray imaging plates. For the first time, nearly the entire grayscale range of the X-ray imaging plate linear response—7819-64 879 in the range of 0-65 535—has been observed. Further, we discuss the uncertainties involved in the calibration process. This work demonstrates the excellent linear response qualities of X-ray imaging plates and provides a significant foundation for expanding their quantitative applied range.

  17. [Response evaluation in nuclear medicine : Criteria, results and pitfalls].

    PubMed

    Hoffend, J; Sachpekidis, C; Dimitrakopoulou-Strauss, A

    2017-09-05

    Established criteria to categorize metabolic tumor response to cytotoxic chemotherapies may not be suited to capture the effects of therapy with immune checkpoint inhibitors (ICI) or with kinase inhibitors (KI), such as BRAF or MEK inhibitors. To assess the metabolic response to cytotoxic chemotherapy by positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG), the criteria of the European Organization for Research and Treatment of Cancer (EORTC) and the positron emission tomography response criteria in solid tumors (PERCIST) were conceived. The salient features of both criteria are detailed in a comparative way. To date only retrospective data exist for the evaluation of therapies with either ICI or KI. They show that response to ICI cannot be reliably determined using the established criteria. Employing the EORTC criteria the responses to KI can be adequately ascertained so that the metabolic tumor response in FDG-PET is regarded as a surrogate marker for the efficacy of these drugs. Tumor response to therapy with ICI cannot at present be assessed with FDG-PET. Responses to BRAF and MEK inhibitors are, however, assessable using the criteria that were originally developed to evaluate responses to cytotoxic chemotherapy.

  18. Imaging Modalities for Assessment of Treatment Response to Nonsurgical Hepatocellular Carcinoma Therapy: Contrast-Enhanced US, CT, and MRI.

    PubMed

    Minami, Yasunori; Kudo, Masatoshi

    2015-03-01

    Tumor response and time to progression have been considered pivotal for surrogate assessment of treatment efficacy for patients with hepatocellular carcinoma (HCC). Recent advancements in imaging modalities such as contrast-enhanced ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are playing an important role in assessing the therapeutic effects of HCC treatments. According to some HCC clinical guidelines, post-therapeutic evaluation of HCC patients is based exclusively on contrast-enhanced dynamic imaging criteria. The recommended techniques are contrast-enhanced CT or contrast-enhanced MRI. Contrast-enhanced US is employed more in the positive diagnosis of HCC than in post-therapeutic monitoring. Although contrast enhancement is an important finding on imaging, enhancement does not necessarily depict the same phenomenon across modalities. We need to become well acquainted with the characteristics of each modality, including not only contrast-enhanced CT and MRI but also contrast-enhanced US. Many nonsurgical treatment options are now available for unresectable HCC, and accurate assessment of tumor response is essential to achieve favorable outcomes. For the assessment of successful radiofrequency ablation (RFA), the achievement of a sufficient ablation margin as well the absence of tumor vascular enhancement is essential. To evaluate the response to transcatheter arterial chemoembolization (TACE), enhanced tumor shrinkage is relied on as a measure of antitumor activity. Here, we give an overview of the current status of imaging assessment of HCC response to nonsurgical treatments including RFA and TACE.

  19. Therapeutic response in musculoskeletal soft tissue sarcomas: evaluation by MRI.

    PubMed

    Wang, Xin; Jacobs, Michael A; Fayad, Laura

    2011-07-01

    This article provides a literature review of the use of MRI in monitoring the treatment response of soft tissue sarcomas. The basic classification and physiology of soft tissue tumors are introduced. Then, the major treatment options for soft tissue sarcomas are summarized with brief coverage of possible responses and grading systems. Four major branches of MRI techniques are covered, including conventional T(1) - and T(2) -weighted imaging, contrast-enhanced MRI, MR diffusion and perfusion imaging, and MRS, with a focus on the tumor microenvironment. Although this literature survey focuses on recent clinical developments using these MRI techniques, research venues in preclinical studies, as well as in potential applications other than soft tissue sarcomas, are also included when comparable and/or mutually supporting. Examples from other less-discussed MRI modalities are also briefly covered, not only to complement, but also to expand, the scope and depth of information for various kinds of lesions. Copyright © 2011 John Wiley & Sons, Ltd.

  20. Interpreting response time effects in functional imaging studies

    PubMed Central

    Taylor, J.S.H.; Rastle, Kathleen; Davis, Matthew H.

    2014-01-01

    It has been suggested that differential neural activity in imaging studies is most informative if it is independent of response time (RT) differences. However, others view RT as a behavioural index of key cognitive processes, which is likely linked to underlying neural activity. Here, we reconcile these views using the effort and engagement framework developed by Taylor, Rastle, and Davis (2013) and data from the domain of reading aloud. We propose that differences in neural engagement should be independent of RT, whereas, differences in neural effort should co-vary with RT. We illustrate these different mechanisms using data from an fMRI study of neural activity during reading aloud of regular words, irregular words, and pseudowords. In line with our proposals, activation revealed by contrasts designed to tap differences in neural engagement (e.g., words are meaningful and therefore engage semantic representations more than pseudowords) survived correction for RT, whereas activation for contrasts designed to tap differences in neural effort (e.g., it is more difficult to generate the pronunciation of pseudowords than words) correlated with RT. However, even for contrasts designed to tap neural effort, activity remained after factoring out the RT–BOLD response correlation. This may reveal unpredicted differences in neural engagement (e.g., learning phonological forms for pseudowords > words) that could further the development of cognitive models of reading aloud. Our framework provides a theoretically well-grounded and easily implemented method for analysing and interpreting RT effects in neuroimaging studies of cognitive processes. PMID:24904992

  1. Experimental evaluation of a hyperspectral imager for near-infrared fluorescent contrast agent studies

    NASA Astrophysics Data System (ADS)

    Luthman, A. S.; Bohndiek, Sarah E.

    2015-03-01

    Hyperspectral imaging (HSI) systems have the potential to combine morphological and spectral information to provide detailed and high sensitivity readouts in biological and medical applications. As HSI enables simultaneous detection in several spectral bands, the technology has significant potential for use in real-time multiplexed contrast agent studies. Examples include tumor detection in intraoperative and endoscopic imaging as well as histopathology. A multiplexed readout from multiple disease targets, such as cell surface receptors overexpressed in cancer cells, could improve both sensitivity and specificity of tumor identification. Here, we evaluate a commercial, compact, near-infrared HSI sensor that has the potential to enable low cost, video rate HSI for multiplexed fluorescent contrast agent studies in biomedical applications. The hyperspectral imager, based on a monolithically integrated Fabry-Perot etalon, has 70 spectral bands between 600-900 nm, making it ideal for this application. Initial calibration of the imager was performed to determine wavelength band response, quantum efficiency and the effect of F-number on the spectral response. A platform for wide-field fluorescence imaging in reflectance using fluorophore specific LED excitation was then developed. The applicability of the imaging platform for simultaneous readout of multiple fluorophore signals was demonstrated using a dilution series of Alexa Fluor 594 and Alexa Fluor 647, showing that nanomolar fluorophore concentrations can be detected. Our results show that the HSI system can clearly resolve the emission spectra of the two fluorophores in mixtures of concentrations across several orders of magnitude, indicating a high dynamic range performance. We therefore conclude that the HSI sensor tested here is suitable for detecting fluorescence in biomedical imaging applications.

  2. Evaluation of ZY-3 for Dsm and Ortho Image Generation

    NASA Astrophysics Data System (ADS)

    d'Angelo, P.

    2013-04-01

    DSM generation using stereo satellites is an important topic for many applications. China has launched the three line ZY-3 stereo mapping satellite last year. This paper evaluates the ZY-3 performance for DSM and orthophoto generation on two scenes east of Munich. The direct georeferencing performance is tested using survey points, and the 3D RMSE is 4.5 m for the scene evaluated in this paper. After image orientation with GCPs and tie points, a DSM is generated using the Semi-Global Matching algorithm. For two 5 × 5 km2 test areas, a LIDAR reference DTM was available. After masking out forest areas, the overall RMSE between ZY-3 DSM and LIDAR reference is 2.0 m (RMSE). Additionally, qualitative comparison between ZY-3 and Cartosat-1 DSMs is performed.

  3. Image reconstruction and image quality evaluation for a dual source CT scanner

    PubMed Central

    Flohr, T. G.; Bruder, H.; Stierstorfer, K.; Petersilka, M.; Schmidt, B.; McCollough, C. H.

    2008-01-01

    The authors present and evaluate concepts for image reconstruction in dual source CT (DSCT). They describe both standard spiral (helical) DSCT image reconstruction and electrocardiogram (ECG)-synchronized image reconstruction. For a compact mechanical design of the DSCT, one detector (A) can cover the full scan field of view, while the other detector (B) has to be restricted to a smaller, central field of view. The authors develop an algorithm for scan data completion, extrapolating truncated data of detector (B) by using data of detector (A). They propose a unified framework for convolution and simultaneous 3D backprojection of both (A) and (B) data, with similar treatment of standard spiral, ECG-gated spiral, and sequential (axial) scan data. In ECG-synchronized image reconstruction, a flexible scan data range per measurement system can be used to trade off temporal resolution for reduced image noise. Both data extrapolation and image reconstruction are evaluated by means of computer simulated data of anthropomorphic phantoms, by phantom measurements and patient studies. The authors show that a consistent filter direction along the spiral tangent on both detectors is essential to reduce cone-beam artifacts, requiring truncation of the extrapolated (B) data after convolution in standard spiral scans. Reconstructions of an anthropomorphic thorax phantom demonstrate good image quality and dose accumulation as theoretically expected for simultaneous 3D backprojection of the filtered (A) data and the truncated filtered (B) data into the same 3D image volume. In ECG-gated spiral modes, spiral slice sensitivity profiles (SSPs) show only minor dependence on the patient’s heart rate if the spiral pitch is properly adapted. Measurements with a thin gold plate phantom result in effective slice widths (full width at half maximum of the SSP) of 0.63–0.69mm for the nominal 0.6mm slice and 0.82–0.87mm for the nominal 0.75mm slice. The visually determined through-plane (z

  4. Filter Design and Performance Evaluation for Fingerprint Image Segmentation.

    PubMed

    Thai, Duy Hoang; Huckemann, Stephan; Gottschlich, Carsten

    2016-01-01

    Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing step of most fingerprint algorithms and it divides an image into foreground, the region of interest, and background. Two types of error can occur during this step which both have a negative impact on the recognition performance: 'true' foreground can be labeled as background and features like minutiae can be lost, or conversely 'true' background can be misclassified as foreground and spurious features can be introduced. The contribution of this paper is threefold: firstly, we propose a novel factorized directional bandpass (FDB) segmentation method for texture extraction based on the directional Hilbert transform of a Butterworth bandpass (DHBB) filter interwoven with soft-thresholding. Secondly, we provide a manually marked ground truth segmentation for 10560 images as an evaluation benchmark. Thirdly, we conduct a systematic performance comparison between the FDB method and four of the most often cited fingerprint segmentation algorithms showing that the FDB segmentation method clearly outperforms these four widely used methods. The benchmark and the implementation of the FDB method are made publicly available.

  5. Radiological Evaluation of Ambiguous Genitalia with Various Imaging Modalities

    NASA Astrophysics Data System (ADS)

    Ravi, N.; Bindushree, Kadakola

    2012-07-01

    Disorders of sex development (DSDs) are congenital conditions in which the development of chromosomal, gonadal, or anatomic sex is atypical. These can be classified broadly into four categories on the basis of gonadal histologic features: female pseudohermaphroditism (46,XX with two ovaries); male pseudohermaphroditism (46,XY with two testes); true hermaphroditism (ovotesticular DSD) (both ovarian and testicular tissues); and gonadal dysgenesis, either mixed (a testis and a streak gonad) or pure (bilateral streak gonads). Imaging plays an important role in demonstrating the anatomy and associated anomalies. Ultrasonography is the primary modality for demonstrating internal organs and magnetic resonance imaging is used as an adjunct modality to assess for internal gonads and genitalia. Early and appropriate gender assignment is necessary for healthy physical and psychologic development of children with ambiguous genitalia. Gender assignment can be facilitated with a team approach that involves a pediatric endocrinologist, geneticist, urologist, psychiatrist, social worker, neonatologist, nurse, and radiologist, allowing timely diagnosis and proper management. We describe case series on ambiguous genitalia presented to our department who were evaluated with multiple imaging modalities.

  6. Filter Design and Performance Evaluation for Fingerprint Image Segmentation

    PubMed Central

    Thai, Duy Hoang; Huckemann, Stephan; Gottschlich, Carsten

    2016-01-01

    Fingerprint recognition plays an important role in many commercial applications and is used by millions of people every day, e.g. for unlocking mobile phones. Fingerprint image segmentation is typically the first processing step of most fingerprint algorithms and it divides an image into foreground, the region of interest, and background. Two types of error can occur during this step which both have a negative impact on the recognition performance: ‘true’ foreground can be labeled as background and features like minutiae can be lost, or conversely ‘true’ background can be misclassified as foreground and spurious features can be introduced. The contribution of this paper is threefold: firstly, we propose a novel factorized directional bandpass (FDB) segmentation method for texture extraction based on the directional Hilbert transform of a Butterworth bandpass (DHBB) filter interwoven with soft-thresholding. Secondly, we provide a manually marked ground truth segmentation for 10560 images as an evaluation benchmark. Thirdly, we conduct a systematic performance comparison between the FDB method and four of the most often cited fingerprint segmentation algorithms showing that the FDB segmentation method clearly outperforms these four widely used methods. The benchmark and the implementation of the FDB method are made publicly available. PMID:27171150

  7. Image Theory's Compatibility Test and Evaluations of the Status Quo.

    PubMed

    Richmond; Bissell; Beach

    1998-01-01

    The research on image theory's concept of progress decisions about either (1) the acceptability of the status quo vis a desired state or (2) the acceptability of movement toward a desired state has been limited to the laboratory. To demonstrate the feasibility of research on nonlaboratory, job-related progress decisions and to develop methods for doing it with minimal intrusion on participant work time, two experiments examined evaluations of the status quo vis a desired state in the context of three organizations: a controller's office, a pretrial services office, and a chain of fast food restaurants. Experiment 1 used fairly elaborate, time consuming methods in the controller's office and pretrial services office to measure the compatibility between participants' images of desirable supervision and their images of current supervision as well as their satisfaction with both supervision and with the organization. In both cases, as compatibility decreased, satisfaction decreased, but satisfaction with the organization appeared to derive from satisfaction with supervision rather than directly from compatibility. Experiment 2 measured the same concepts in the fast food chain using simple, single-item methods, obtaining roughly the same results as Experiment 1, except that it also demonstrated that hope for change can mitigate the effects of incompatibility on satisfaction. These results provide evidence for the role of compatibility in decision making and for the feasibility of using simple methods of measuring compatibility, acceptability, and hope in nonlaboratory research. Copyright 1998 Academic Press.

  8. Evaluation of cutaneous body image dissatisfaction in the dermatology patient.

    PubMed

    Gupta, Madhulika A; Gupta, Aditya K

    2013-01-01

    Cutaneous body image (CBI), defined as the individual's mental representation of his or her skin, hair, and nails, is an important clinical factor in dermatologic disorders and often the primary consideration in deciding whether to proceed with cosmetic procedures or institute treatment in some skin disorders such as acne. CBI is a highly subjective construct that can be significantly confounded by cultural, psychosocial, and psychiatric factors. Assessment of CBI in the dermatology patient is best accomplished using a biopsychosocial model that involves (1) evaluation of concerns about the appearance of the skin, hair, and nails, (2) assessment of comorbid body image pathologies, especially body dysmorphic disorder, and (3) assessment of other psychiatric comorbidities such as major depressive disorder that can confound the presentation of the CBI complaint. Depending on the psychiatric comobidities, an assessment of suicide risk may have to be done, and if necessary, a referral made to a mental health professional. The clinician should consider the patient's developmental stage (eg, body image concerns are likely to be much greater in the adolescent patient independent of his or her dermatologic disorder) and sociocultural background (eg, a desire for lighter skin in some ethnic groups), factors that can also have a major effect on CBI. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Developing oxygen-enhanced magnetic resonance imaging as a prognostic biomarker of radiation response.

    PubMed

    White, Derek A; Zhang, Zhang; Li, Li; Gerberich, Jeni; Stojadinovic, Strahinja; Peschke, Peter; Mason, Ralph P

    2016-09-28

    Oxygen-Enhanced Magnetic Resonance Imaging (OE-MRI) techniques were evaluated as potential non-invasive predictive biomarkers of radiation response. Semi quantitative blood-oxygen level dependent (BOLD) and tissue oxygen level dependent (TOLD) contrast, and quantitative responses of relaxation rates (ΔR1 and ΔR2*) to an oxygen breathing challenge during hypofractionated radiotherapy were applied. OE-MRI was performed on subcutaneous Dunning R3327-AT1 rat prostate tumors (n=25) at 4.7 T prior to each irradiation (2F × 15 Gy) to the gross tumor volume. Response to radiation, while inhaling air or oxygen, was assessed by tumor growth delay measured up to four times the initial irradiated tumor volume (VQT). Radiation-induced hypoxia changes were confirmed using a double hypoxia marker assay. Inhaling oxygen during hypofractionated radiotherapy significantly improved radiation response. A correlation was observed between the difference in the 2nd and 1st ΔR1 (ΔΔR1) and VQT for air breathing rats. The TOLD response before the 2nd fraction showed a moderate correlation with VQT for oxygen breathing rats. The correlations indicate useful prognostic factors to predict tumor response to hypofractionation and could readily be applied for patient stratification and personalized radiotherapy treatment planning. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Ultrasonography and magnetic resonance imaging evaluation of pediatric spinal anomalies

    PubMed Central

    Dhingani, Dhaval Durlabhbhai; Boruah, Deb Kumar; Dutta, Hemonta Kumar; Gogoi, Rudra Kanta

    2016-01-01

    Context: Spinal dysraphisms are congenital abnormalities of the spine due to imperfect fusion of midline mesenchymal, bony and neural structures. Imaging plays a vital role in their evaluation as significant portion of patients may present with concurrent anomalies that need to be corrected simultaneously to avoid repeat surgeries. Aims: The aims of the study were to evaluate Spinal dysraphisms using USG and MRI and to correlate imaging findings with operative findings in patients undergoing surgery. Settings and Design: Hospital based observational study conducted over a period of year. Materials and Methods: 38 cases of both sexes and below 12 years of age with spinal dysraphism were studied. USG was performed in 29 cases where acoustic window was available for proper evaluation. MRI was performed in all cases. USG findings were compared with MRI findings and operative follow up was taken in 23 cases who underwent operative management. Statistical Analysis Used: Results were analysed using percentage and arithmetic mean. Results: 39.47 % cases were male and 60.53 % cases were female. Neonatal period was the most common presenting age group. Closed spinal dysraphism (63.16%) was more common than open (36.84%). 79.31% cases showed full agreement between spinal USG and MRI examinations and 6 out of 20.69% showed partial agreement. On operative correlation, USG findings were confirmatory in 91.30% cases and MRI findings were confirmatory in 100% cases. Conclusions: USG can be used as the initial modality for evaluation of spinal dysraphism as well as for screening of suspected cases. MRI is indicated to confirm abnormal USG findings, which shows all concurrent abnormalities and also provides additional anatomical details relevant to surgical planning. PMID:27857788

  11. Multi-Parametric Monitoring of Tumor Response to Chemotherapy by Non-Invasive Imaging

    PubMed Central

    Medarova, Zdravka; Rashkovetsky, Leonid; Pantazopoulos, Pamela; Moore, Anna

    2008-01-01

    With the emerging concept of individualized cancer therapy, it becomes crucial to develop methods for the noninvasive assessment of treatment outcome. With this in mind, we designed a novel approach for the comprehensive evaluation of response to chemotherapy with the established agent doxorubicin in a pre-clinical breast cancer model. This approach delivers information not only about change in tumor size but also about target antigen expression. Our strategy relies on a tumor-specific contrast agent (MN-EPPT) targeting the underglycosylated MUC-1 (uMUC-1) tumor antigen, found on over 90% of breast cancers and predictive of chemotherapeutic response. MN-EPPT consists of superparamagnetic iron oxide nanoparticles (MN) for magnetic resonance imaging, modified with Cy5.5 dye (for near-infrared fluorescence optical imaging, NIRF), and conjugated to peptides (EPPT), specifically recognizing uMUC-1. In vivo, treatment of mice bearing orthotopic human breast carcinomas with doxorubicin led to a reduction in tumor mass and resulted in downregulation of uMUC-1. The tumor-specific accumulation of MN-EPPT allowed the assessment of change in tumor volume by noninvasive imaging. Furthermore, in mice injected with MN-EPPT, tumor delta-T2 was significantly reduced after treatment with doxorubicin, indicating a lower accumulation of MN-EPPT and reflecting the reduced expression of uMUC-1. With these studies, we have demonstrated the utility of magnetic resonance imaging for the multiparametric characterization of breast tumor response to chemotherapy. This approach has the potential of significantly advancing our ability to better direct the development of molecularly-targeted individualized therapy protocols, since it permits the monitoring of therapy on a molecular scale. PMID:19141648

  12. Evaluation of laser prostatectomy devices by thermal imaging

    NASA Astrophysics Data System (ADS)

    Molenaar, David G.; van Vliet, Remco J.; van Swol, Christiaan F. P.; Boon, Tom A.; Verdaasdonck, Rudolf M.

    1994-12-01

    The treatment of benign prostatic hyperplasia (BPH) using Nd:YAG laser light has become an accepted alternative to TURP. However, there is no consensus to the dosimetry using the various laser devices. In our study, we evaluate the optical and thermal characteristics of 7 commercially available side firing laser probes. For the thermal analysis, an optical method was used based on `Schlieren' techniques producing color images of the temperature distribution around the laser probe in water. Absolute temperatures were obtained after calibration measurements with thermocouples. Laser probes using metal mirrors for beam deflection heated up entirely. The local temperature rose up to 100 degrees centigrade, thus inducing vapor bubble formation that interfered with the emitted beam. Laser devices, using total internal reflection for deflection, showed far less heating primarily at the exit window, though Fresnel reflections and secondary beams indirectly heated up the (metal) housing of the tip. After clinical application, the absorption at the probe surface and hence temperature increased due to probe deterioration. Color Schlieren imaging is a powerful method for the thermal evaluation of laser devices. The thermal behavior of laser probes can be used as a guidance for the method of application and as an indication of the lifetime of the probes.

  13. Refinery evaluation of optical imaging to locate fugitive emissions.

    PubMed

    Robinson, Donald R; Luke-Boone, Ronke; Aggarwal, Vineet; Harris, Buzz; Anderson, Eric; Ranum, David; Kulp, Thomas J; Armstrong, Karla; Sommers, Ricky; McRae, Thomas G; Ritter, Karin; Siegell, Jeffrey H; Van Pelt, Doug; Smylie, Mike

    2007-07-01

    Fugitive emissions account for approximately 50% of total hydrocarbon emissions from process plants. Federal and state regulations aiming at controlling these emissions require refineries and petrochemical plants in the United States to implement a Leak Detection and Repair Program (LDAR). The current regulatory work practice, U.S. Environment Protection Agency Method 21, requires designated components to be monitored individually at regular intervals. The annual costs of these LDAR programs in a typical refinery can exceed US$1,000,000. Previous studies have shown that a majority of controllable fugitive emissions come from a very small fraction of components. The Smart LDAR program aims to find cost-effective methods to monitor and reduce emissions from these large leakers. Optical gas imaging has been identified as one such technology that can help achieve this objective. This paper discusses a refinery evaluation of an instrument based on backscatter absorption gas imaging technology. This portable camera allows an operator to scan components more quickly and image gas leaks in real time. During the evaluation, the instrument was able to identify leaking components that were the source of 97% of the total mass emissions from leaks detected. More than 27,000 components were monitored. This was achieved in far less time than it would have taken using Method 21. In addition, the instrument was able to find leaks from components that are not required to be monitored by the current LDAR regulations. The technology principles and the parameters that affect instrument performance are also discussed in the paper.

  14. Sensitivity evaluation and selective plane imaging geometry for x-ray-induced luminescence imaging.

    PubMed

    Quigley, Bryan P; Smith, Corey D; Cheng, Shih-Hsun; Souris, Jeffrey S; Pelizzari, Charles A; Chen, Chin-Tu; Lo, Leu-Wei; Reft, Chester S; Wiersma, Rodney D; La Riviere, Patrick J

    2017-07-13

    X-ray-induced luminescence (XIL) is a hybrid x-ray/optical imaging modality that employs nanophosphors that luminescence in response to x-ray irradiation. X-ray-activated phosphorescent nanoparticles have potential applications in radiation therapy as theranostics, nanodosimeters, or radiosensitizers. Extracting clinically relevant information from the luminescent signal requires the development of a robust imaging model that can determine nanophosphor distributions at depth in an optically scattering environment from surface radiance measurements. The applications of XIL in radiotherapy will be limited by the dose-dependent sensitivity at depth in tissue. We propose a novel geometry called selective plane XIL (SPXIL), and apply it to experimental measurements in optical gel phantoms and sensitivity simulations. An imaging model is presented based on the selective plane geometry which can determine the detected diffuse optical signal for a given x-ray dose and nanophosphor distribution at depth in a semi-infinite, optically homogenous material. The surface radiance in the model is calculated using an analytical solution to the extrapolated boundary condition. Y2 O3 :Eu(3+) nanoparticles are synthesized and inserted into various optical phantom in order to measure the luminescent output per unit dose for a given concentration of nanophosphors and calibrate an imaging model for XIL sensitivity simulations. SPXIL imaging with a dual-source optical gel phantom is performed, and an iterative Richardson-Lucy deconvolution using a shifted Poisson noise model is applied to the measurements in order to reconstruct the nanophosphor distribution. Nanophosphor characterizations showed a peak emission at 611 nm, a linear luminescent response to tube current and nanoparticle concentration, and a quadratic luminescent response to tube voltage. The luminescent efficiency calculation accomplished with calibrated bioluminescence mouse phantoms determines 1.06 photons were emitted

  15. Brain responses to body image stimuli but not food are altered in women with bulimia nervosa

    PubMed Central

    2013-01-01

    Background Research into the neural correlates of bulimia nervosa (BN) psychopathology remains limited. Methods In this functional magnetic resonance imaging study, 21 BN patients and 23 healthy controls (HCs) completed two paradigms: 1) processing of visual food stimuli and 2) comparing their own appearance with that of slim women. Participants also rated food craving and anxiety levels. Results Brain activation patterns in response to food cues did not differ between women with and without BN. However, when evaluating themselves against images of slim women, BN patients engaged the insula more and the fusiform gyrus less, compared to HCs, suggesting increased self-focus among women with BN whilst comparing themselves to a ‘slim ideal’. In these BN patients, exposure to food and body image stimuli increased self-reported levels of anxiety, but not craving. Conclusions Our findings suggest that women with BN differ from HCs in the way they process body image, but not in the way they process food stimuli. PMID:24238299

  16. Image processing and machine learning for fully automated probabilistic evaluation of medical images.

    PubMed

    Sajn, Luka; Kukar, Matjaž

    2011-12-01

    The paper presents results of our long-term study on using image processing and data mining methods in a medical imaging. Since evaluation of modern medical images is becoming increasingly complex, advanced analytical and decision support tools are involved in integration of partial diagnostic results. Such partial results, frequently obtained from tests with substantial imperfections, are integrated into ultimate diagnostic conclusion about the probability of disease for a given patient. We study various topics such as improving the predictive power of clinical tests by utilizing pre-test and post-test probabilities, texture representation, multi-resolution feature extraction, feature construction and data mining algorithms that significantly outperform medical practice. Our long-term study reveals three significant milestones. The first improvement was achieved by significantly increasing post-test diagnostic probabilities with respect to expert physicians. The second, even more significant improvement utilizes multi-resolution image parametrization. Machine learning methods in conjunction with the feature subset selection on these parameters significantly improve diagnostic performance. However, further feature construction with the principle component analysis on these features elevates results to an even higher accuracy level that represents the third milestone. With the proposed approach clinical results are significantly improved throughout the study. The most significant result of our study is improvement in the diagnostic power of the whole diagnostic process. Our compound approach aids, but does not replace, the physician's judgment and may assist in decisions on cost effectiveness of tests. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Objective breast symmetry evaluation using 3-D surface imaging.

    PubMed

    Eder, Maximilian; Waldenfels, Fee V; Swobodnik, Alexandra; Klöppel, Markus; Pape, Ann-Kathrin; Schuster, Tibor; Raith, Stefan; Kitzler, Elena; Papadopulos, Nikolaos A; Machens, Hans-Günther; Kovacs, Laszlo

    2012-04-01

    This study develops an objective breast symmetry evaluation using 3-D surface imaging (Konica-Minolta V910(®) scanner) by superimposing the mirrored left breast over the right and objectively determining the mean 3-D contour difference between the 2 breast surfaces. 3 observers analyzed the evaluation protocol precision using 2 dummy models (n = 60), 10 test subjects (n = 300), clinically tested it on 30 patients (n = 900) and compared it to established 2-D measurements on 23 breast reconstructive patients using the BCCT.core software (n = 690). Mean 3-D evaluation precision, expressed as the coefficient of variation (VC), was 3.54 ± 0.18 for all human subjects without significant intra- and inter-observer differences (p > 0.05). The 3-D breast symmetry evaluation is observer independent, significantly more precise (p < 0.001) than the BCCT.core software (VC = 6.92 ± 0.88) and may play a part in an objective surgical outcome analysis after incorporation into clinical practice.

  18. Standard problems to evaluate piping response computer codes

    SciTech Connect

    Bezler, P.; Subudhi, M.

    1984-01-01

    A program has been underway to evaluate the analysis methods used by industry to qualify nuclear power plant piping. Two objectives of this program are to develop physical benchmarks for validating the accuracy of computer codes used to simulate piping response and to develop improved procedures for calculating the response of multiple supported piping with independent seismic inputs. The status of the program in these two areas is reviewed.

  19. Dynamic contrast-enhanced magnetic resonance imaging for prediction of response to neoadjuvant chemotherapy in breast cancer

    NASA Astrophysics Data System (ADS)

    Fu, Juzhong; Fan, Ming; Zheng, Bin; Shao, Guoliang; Zhang, Juan; Li, Lihua

    2016-03-01

    Breast cancer is the second leading cause of women death in the United States. Currently, Neoadjuvant Chemotherapy (NAC) has become standard treatment paradigms for breast cancer patients. Therefore, it is important to find a reliable non-invasive assessment and prediction method which can evaluate and predict the response of NAC on breast cancer. The Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) approach can reflect dynamic distribution of contrast agent in tumor vessels, providing important basis for clinical diagnosis. In this study, the efficacy of DCE-MRI on evaluation and prediction of response to NAC in breast cancer was investigated. To this end, fifty-seven cases of malignant breast cancers with MRI examination both before and after two cycle of NAC were analyzed. After pre-processing approach for segmenting breast lesions and background regions, 126-dimensional imaging features were extracted from DCE-MRI. Statistical analyses were then performed to evaluate the associations between the extracted DCE-MRI features and the response to NAC. Specifically, pairwise t test was used to calculate differences of imaging features between MRI examinations before-and-after NAC. Moreover, the associations of these image features with response to NAC were assessed using logistic regression. Significant association are found between response to NAC and the features of lesion morphology and background parenchymal enhancement, especially the feature of background enhancement in normal side of breast (P=0.011). Our study indicate that DCE-MRI features can provide candidate imaging markers to predict response of NAC in breast cancer.

  20. Evaluation of the Emergency Response Dose Assessment System(ERDAS)

    NASA Technical Reports Server (NTRS)

    Evans, Randolph J.; Lambert, Winifred C.; Manobianco, John T.; Taylor, Gregory E.; Wheeler, Mark M.; Yersavich, Ann M.

    1996-01-01

    The emergency response dose assessment system (ERDAS) is a protype software and hardware system configured to produce routine mesoscale meteorological forecasts and enhanced dispersion estimates on an operational basis for the Kennedy Space Center (KSC)/Cape Canaveral Air Station (CCAS) region. ERDAS provides emergency response guidance to operations at KSC/CCAS in the case of an accidental hazardous material release or an aborted vehicle launch. This report describes the evaluation of ERDAS including: evaluation of sea breeze predictions, comparison of launch plume location and concentration predictions, case study of a toxic release, evaluation of model sensitivity to varying input parameters, evaluation of the user interface, assessment of ERDA's operational capabilities, and a comparison of ERDAS models to the ocean breeze dry gultch diffusion model.

  1. Image reconstruction and image quality evaluation for a 16-slice CT scanner.

    PubMed

    Flohr, Th; Stierstorfer, K; Bruder, H; Simon, J; Polacin, A; Schaller, S

    2003-05-01

    We present a theoretical overview and a performance evaluation of a novel approximate reconstruction algorithm for cone-beam spiral CT, the adaptive multiple plane reconstruction (AMPR), which has been introduced by Schaller, Flohr et al. [Proc. SPIE Int. Symp. Med. Imag. 4322, 113-127 (2001)] AMPR has been implemented in a recently introduced 16-slice CT scanner. We present a detailed algorithmic description of AMPR which allows for a free selection of the spiral pitch. We show that dose utilization is better than 90% independent of the pitch. We give an overview on the z-reformation functions chosen to allow for a variable selection of the spiral slice width at arbitrary pitch values. To investigate AMPR image quality we present images of anthropomorphic phantoms and initial patient results. We present measurements of spiral slice sensitivity profiles (SSPs) and measurements of the maximum achievable transverse resolution, both in the isocenter and off-center. We discuss the pitch dependence of image noise measured in a centered 20 cm water phantom. Using the AMPR approach, cone-beam artifacts are considerably reduced for the 16-slice scanner investigated. Image quality in MPRs is independent of the pitch and equivalent to a single-slice CT system at pitch p approximately 1.5. The full width at half-maximum (FWHM) of the spiral SSPs shows only minor variations as a function of the pitch, nominal, and measured values differ by less than 0.2 mm. With 16 x 0.75 mm collimation, the measured FWHM of the smallest reconstructed slice is about 0.9 mm. Using this slice width and overlapping image reconstruction, cylindrical holes with 0.6 mm diameter can be resolved in a z-resolution phantom. Image noise for constant effective mAs is nearly independent of the pitch. Measured and theoretically expected dose utilization are in good agreement. Meanwhile, clinical practice has demonstrated the excellent image quality and the increased diagnostic capability that is obtained

  2. Naturalness and interestingness of test images for visual quality evaluation

    NASA Astrophysics Data System (ADS)

    Halonen, Raisa; Westman, Stina; Oittinen, Pirkko

    2011-01-01

    Balanced and representative test images are needed to study perceived visual quality in various application domains. This study investigates naturalness and interestingness as image quality attributes in the context of test images. Taking a top-down approach we aim to find the dimensions which constitute naturalness and interestingness in test images and the relationship between these high-level quality attributes. We compare existing collections of test images (e.g. Sony sRGB images, ISO 12640 images, Kodak images, Nokia images and test images developed within our group) in an experiment combining quality sorting and structured interviews. Based on the data gathered we analyze the viewer-supplied criteria for naturalness and interestingness across image types, quality levels and judges. This study advances our understanding of subjective image quality criteria and enables the validation of current test images, furthering their development.

  3. Impulse Response Estimation for Spatial Resolution Enhancement in Ultrasonic NDE Imaging

    SciTech Connect

    Clark, G A

    2004-06-25

    This report describes a signal processing algorithm and MATLAB software for improving spatial resolution in ultrasonic nondestructive evaluation (NDE) imaging of materials. Given a measured reflection signal and an associated reference signal, the algorithm produces an optimal least-squares estimate of the impulse response of the material under test. This estimated impulse response, when used in place of the raw reflection signal, enhances the spatial resolution of the ultrasonic measurements by removing distortion caused by the limited-bandwidth transducers and the materials under test. The theory behind the processing algorithms is briefly presented, while the reader is referred to the bibliography for details. The main focus of the report is to describe how to use the MATLAB software. Two processing examples using actual ultrasonic measurements are provided for tutorial purposes.

  4. Dual-mode 5-element transducer for image-guided interstitial ultrasound therapy: In vitro evaluation

    NASA Astrophysics Data System (ADS)

    Owen, N. R.; Bouchoux, G.; Murillo-Rincon, A.; Merouche, S.; Birer, A.; Chapelon, J. Y.; Berriet, R.; Fleury, G.; Lafon, C.

    2009-04-01

    Interstitial probes with dual-mode transducers are effective devices to guide and monitor with ultrasound imaging the application of ultrasound therapy. Here, a dual-mode 5-element transducer, with oscillatory motion for sector imaging and directive therapy, was characterized and evaluated in vitro with porcine liver. The transducer had 3.8×3.0-mm2 elements, a 20×3.0-mm2 aperture, and was cylindrically focused to 14-mm. In therapy mode, elements were maximally efficient, 72±4% (ave±std), at 5.6-MHz. In imaging mode, the pulse-echo impulse response for each electrically-matched element was 160±16 ns long at -6 dB, and insertion loss was minimally 9.8±0.5 dB at 5.2-MHz. Electrical crosstalk was less than -57 dB at 5.6-MHz. Lateral resolution, measured by scanning a wire of 0.1-mm diameter wire though the focal plane, was 1.0-mm at -6 dB. During experiment, an initial B-mode image was formed over a 140° sector. Then, therapy was applied for 90 s, with 18-W/cm2 transducer surface intensity, at each of 5 angles (Δθ = 20°) to form volumes of composite protein denaturization. Pulse-echo data were collected periodically to monitor therapy with real-time M-mode imaging. After therapy, another B-mode image was formed, and the depth of protein denaturization was measured by gross histology. B-mode images adequately represented the liver structure. Analysis of M-mode images was consistent with gross histology.

  5. Evaluation of the Compressive Response of Notched Composite Panels using a Full-Field Displacement Measurement System

    NASA Technical Reports Server (NTRS)

    McGowan, David M.; Ambur, Damodar R.; Hanna, T. Glen; McNeill, Stephen R.

    1999-01-01

    An experimental and analytical evaluation of the compressive response of two composite, notched stiffened panels representative of primary composite wing structure is presented. A three-dimensional full-field image correlation technique is used to measure all three displacement components over global and local areas of the test panels. Point-wise and full-field results obtained using the image correlation technique are presented and compared to experimental results and analytical results obtained using nonlinear finite element analysis. Both global and global-local image correlation results are presented and discussed. Results of a simple calibration test of this image correlation technique are also presented.

  6. Classification and Quality Evaluation of Tobacco Leaves Based on Image Processing and Fuzzy Comprehensive Evaluation

    PubMed Central

    Zhang, Fan; Zhang, Xinhong

    2011-01-01

    Most of classification, quality evaluation or grading of the flue-cured tobacco leaves are manually operated, which relies on the judgmental experience of experts, and inevitably limited by personal, physical and environmental factors. The classification and the quality evaluation are therefore subjective and experientially based. In this paper, an automatic classification method of tobacco leaves based on the digital image processing and the fuzzy sets theory is presented. A grading system based on image processing techniques was developed for automatically inspecting and grading flue-cured tobacco leaves. This system uses machine vision for the extraction and analysis of color, size, shape and surface texture. Fuzzy comprehensive evaluation provides a high level of confidence in decision making based on the fuzzy logic. The neural network is used to estimate and forecast the membership function of the features of tobacco leaves in the fuzzy sets. The experimental results of the two-level fuzzy comprehensive evaluation (FCE) show that the accuracy rate of classification is about 94% for the trained tobacco leaves, and the accuracy rate of the non-trained tobacco leaves is about 72%. We believe that the fuzzy comprehensive evaluation is a viable way for the automatic classification and quality evaluation of the tobacco leaves. PMID:22163744

  7. Classification and quality evaluation of tobacco leaves based on image processing and fuzzy comprehensive evaluation.

    PubMed

    Zhang, Fan; Zhang, Xinhong

    2011-01-01

    Most of classification, quality evaluation or grading of the flue-cured tobacco leaves are manually operated, which relies on the judgmental experience of experts, and inevitably limited by personal, physical and environmental factors. The classification and the quality evaluation are therefore subjective and experientially based. In this paper, an automatic classification method of tobacco leaves based on the digital image processing and the fuzzy sets theory is presented. A grading system based on image processing techniques was developed for automatically inspecting and grading flue-cured tobacco leaves. This system uses machine vision for the extraction and analysis of color, size, shape and surface texture. Fuzzy comprehensive evaluation provides a high level of confidence in decision making based on the fuzzy logic. The neural network is used to estimate and forecast the membership function of the features of tobacco leaves in the fuzzy sets. The experimental results of the two-level fuzzy comprehensive evaluation (FCE) show that the accuracy rate of classification is about 94% for the trained tobacco leaves, and the accuracy rate of the non-trained tobacco leaves is about 72%. We believe that the fuzzy comprehensive evaluation is a viable way for the automatic classification and quality evaluation of the tobacco leaves.

  8. Comparison of magnetic resonance imaging and radionuclide imaging in the evaluation of renal transplant failure

    SciTech Connect

    Goldsmith, M.S.; Tanasescu, D.E.; Waxman, A.D.; Crues, J.V. III

    1988-04-01

    Magnetic resonance imaging (MRI) was compared with radionuclide scintigraphy (RNS) in 16 patients with renal transplants undergoing renal failure to determine which modality could best discriminate between rejection, acute tubular necrosis (ATN), and cyclosporin nephrotoxicity (CN). Although all rejecting transplants had reduced corticomedullary differentiation (CMD) on T1-weighted MR images, four of five cases of ATN had appearances that could not be distinguished from rejection. A normal CMD suggests nonrejection, but diminished CMD is nonspecific. Tc-99m DTPA/I-131 hippuran RNS was superior to MRI in differentiating rejection from ATN. Although ATN and CN have similar RNS patterns, this distinction can usually be made based on the clinical time course. Other potential uses of MRI in the evaluation of the renal transplants are discussed.

  9. High dynamic range hyperspectral imaging for camouflage performance test and evaluation

    NASA Astrophysics Data System (ADS)

    Pearce, D.; Feenan, J.

    2016-10-01

    This paper demonstrates the use of high dynamic range processing applied to the specific technique of hyper-spectral imaging with linescan spectrometers. The technique provides an improvement in signal to noise for reflectance estimation. This is demonstrated for field measurements of rural imagery collected from a ground-based linescan spectrometer of rural scenes. Once fully developed, the specific application is expected to improve the colour estimation approaches and consequently the test and evaluation accuracy of camouflage performance tests. Data are presented on both field and laboratory experiments that have been used to evaluate the improvements granted by the adoption of high dynamic range data acquisition in the field of hyperspectral imaging. High dynamic ranging imaging is well suited to the hyperspectral domain due to the large variation in solar irradiance across the visible and short wave infra-red (SWIR) spectrum coupled with the wavelength dependence of the nominal silicon detector response. Under field measurement conditions it is generally impractical to provide artificial illumination; consequently, an adaptation of the hyperspectral imaging and re ectance estimation process has been developed to accommodate the solar spectrum. This is shown to improve the signal to noise ratio for the re ectance estimation process of scene materials in the 400-500 nm and 700-900 nm regions.

  10. In vivo macrophage imaging using MR targeted contrast agent for longitudinal evaluation of septic arthritis.

    PubMed

    Bierry, Guillaume; Lefevre, Sophie; Dietemann, Jean-Louis; Jehl, François

    2013-10-20

    Macrophages are key-cells in the initiation, the development and the regulation of the inflammatory response to bacterial infection. Macrophages are intensively and increasingly recruited in septic joints from the early phases of infection and the infiltration is supposed to regress once efficient removal of the pathogens is obtained. The ability to identify in vivo macrophage activity in an infected joint can therefore provide two main applications: early detection of acute synovitis and monitoring of therapy. In vivo noninvasive detection of macrophages can be performed with magnetic resonance imaging using iron nanoparticles such as ultrasmall superparamagnetic iron oxide (USPIO). After intravascular or intraarticular administration, USPIO are specifically phagocytized by activated macrophages, and, due to their magnetic properties, induce signal changes in tissues presenting macrophage infiltration. A quantitative evaluation of the infiltrate is feasible, as the area with signal loss (number of dark pixels) observed on gradient echo MR images after particles injection is correlated with the amount of iron within the tissue and therefore reflects the number of USPIO-loaded cells. We present here a protocol to perform macrophage imaging using USPIO-enhanced MR imaging in an animal model of septic arthritis, allowing an initial and longitudinal in vivo noninvasive evaluation of macrophages infiltration and an assessment of therapy action.

  11. Application of Advanced Magnetic Resonance Imaging Techniques in Evaluation of the Lower Extremity

    PubMed Central

    Braun, Hillary J.; Dragoo, Jason L.; Hargreaves, Brian A.; Levenston, Marc E.; Gold, Garry E.

    2012-01-01

    Synopsis This article reviews current magnetic resonance imaging techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MRI include imaging at 7 Tesla, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphological changes within articular cartilage, and imaging around orthopedic hardware. PMID:23622097

  12. Implementation and evaluation of various demons deformable image registration algorithms on a GPU.

    PubMed

    Gu, Xuejun; Pan, Hubert; Liang, Yun; Castillo, Richard; Yang, Deshan; Choi, Dongju; Castillo, Edward; Majumdar, Amitava; Guerrero, Thomas; Jiang, Steve B

    2010-01-07

    Online adaptive radiation therapy (ART) promises the ability to deliver an optimal treatment in response to daily patient anatomic variation. A major technical barrier for the clinical implementation of online ART is the requirement of rapid image segmentation. Deformable image registration (DIR) has been used as an automated segmentation method to transfer tumor/organ contours from the planning image to daily images. However, the current computational time of DIR is insufficient for online ART. In this work, this issue is addressed by using computer graphics processing units (GPUs). A gray-scale-based DIR algorithm called demons and five of its variants were implemented on GPUs using the compute unified device architecture (CUDA) programming environment. The spatial accuracy of these algorithms was evaluated over five sets of pulmonary 4D CT images with an average size of 256 x 256 x 100 and more than 1100 expert-determined landmark point pairs each. For all the testing scenarios presented in this paper, the GPU-based DIR computation required around 7 to 11 s to yield an average 3D error ranging from 1.5 to 1.8 mm. It is interesting to find out that the original passive force demons algorithms outperform subsequently proposed variants based on the combination of accuracy, efficiency and ease of implementation.

  13. Response evaluation after chemoradiotherapy for advanced staged oropharyngeal squamous cell carcinoma: a nationwide survey in the Netherlands.

    PubMed

    Schouten, Charlotte S; Hoekstra, Otto S; Leemans, C René; Castelijns, Jonas A; de Bree, Remco

    2015-11-01

    Following failure of chemoradiotherapy (CRT) for advanced staged oropharyngeal squamous cell carcinomas (OPSCC), residual tumor can often be treated successfully with salvage surgery, if detected early. Current clinical practice in the VU University Medical Center is to perform routine response evaluation, i.e., examination under general anesthesia (EUA), 12 weeks after treatment. However, in the Netherlands there is no consensus on response evaluation in patients with advanced oropharyngeal cancer. Questionnaire on current clinical practice concerning response evaluation after CRT for advanced OPSCC in all eight head and neck cancer centers of the Dutch Head and Neck Oncology Cooperative Group. The response rate was 100%. Response evaluation was routinely performed with various methods in five institutions (62.5%) and in one institute (12.5%) only if clinical evaluation was difficult. Two centers (25%) did not perform response evaluation. In case of suspicion of residual disease during follow-up, six centers (75%) performed imaging prior to EUA and two centers (25%) only if clinical evaluation was difficult. Diagnostic techniques used prior to EUA were MRI (87.5%), diffusion-weighted MRI (37.5%), 18F-FDG-PET-CT (75-87.5%) and CT (37.5%). This survey shows a substantial variation in the diagnostic policy concerning response evaluation after CRT for advanced OPSCC in the Netherlands. There is a need for guidelines for response evaluation in patients with advanced oropharyngeal cancer.

  14. Equivalent cross-relaxation rate imaging and diffusion weighted imaging for early prediction of response to bevacizumab-containing treatment in colorectal liver metastases-preliminary study.

    PubMed

    Matsushima, Shigeru; Sato, Takeshi; Nishiofuku, Hideyuki; Sato, Yozo; Murata, Shinichi; Kinosada, Yasutomi; Era, Seiichi; Inaba, Yoshitaka

    To evaluate and compare the usefulness of equivalent cross-relaxation rate (ECR) imaging (ECRI) and diffusion-weighted imaging (DWI) in the early prediction of the response of bevacizumab-containing treatments of colorectal liver metastases. Seven patients received bevacizumab-containing treatments for colorectal liver metastases. Serial magnetic resonance imaging was performed to evaluate responses before and 2 weeks after starting chemotherapy. In the ECRI, we adopted the off-resonance technique for preferential saturation of immobile protons to evaluate the ECR values. A single saturation transfer pulse frequency was used at a frequency of 3.5 ppm downfield from the water resonance. In the DWI, the apparent diffusion coefficient (ADC) value commonly used with two b-values was acquired by using diffusion weightings of 0 and 800 s/mm(2). The region of interest of the metastatic lesions in the liver was separately measured by ECRI and DWI. Tumor response was assessed by response evaluation criteria in solid tumors criteria 8 weeks after starting chemotherapy. In this study, we had four responders and three nonresponders. There was a significant difference in the pretreatment ECR values between the responders and nonresponders (P=.01); there was no significant difference in the ADC values between the two groups. Analysis of the percentage difference between the pretreatment and post-treatment values, termed as percentage change, showed that there were no significant differences in the percentage change of the ADC values between both groups; however, the percentage change in the ECR value was significantly greater for the responders than for the nonresponders (-41.6%±17.1% vs. -12.9%±6.9%, respectively; P=.04). The pretreatment ECR value and percentage change of the ECR value 2 weeks after starting chemotherapy were useful parameters in the early prediction of response to bevacizumab-containing treatment in colorectal liver metastases. Copyright © 2016 Elsevier

  15. Evaluation of human detection performance of targets embedded in natural and enhanced infrared images using image metrics

    NASA Astrophysics Data System (ADS)

    Aviram, Guy; Rotman, Stanley R.

    2000-04-01

    The evaluation of human detection performance of targets embedded in natural IR images is uniquely extended to deal with enhanced images. Various image metrics designed to describe global image clutter and local target-to-background contrast are presented. Agreement between experimental results, as obtained for both natural and enhanced IR images and image metrics, is evaluated by correcting the metric values with target detection results obtained from two psycho-physical experiments, which were designed to record and measure human target detection performance and image quality judgments. Positive correlation values are generally obtained between the metric values and both the target detection (rate and probability) performance and the image quality scale values. More specifically, the local contrast metric is found to be the most suitable to the data recorded from the quality judgments experiment, while the global clutter metric is found to be the most suitable to the data recorded from the detection performance experiments. Further analysis of the relationship between the image metrics and the experimental results yield empirical classification thresholds that can be used to evaluate and predict human detection performance in similar cases. A method to evaluate the classification efficiency, is introduced and used to reconfirm the metrics appropriateness to describe detection performance and quality judgments of targets embedded in both natural and enhanced images.

  16. 40 CFR 265.93 - Preparation, evaluation, and response.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., STORAGE, AND DISPOSAL FACILITIES Ground-Water Monitoring § 265.93 Preparation, evaluation, and response... an outline of a ground-water quality assessment program. The outline must describe a more comprehensive ground-water monitoring program (than that described in §§ 265.91 and 265.92) capable of...

  17. 40 CFR 265.93 - Preparation, evaluation, and response.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., STORAGE, AND DISPOSAL FACILITIES Ground-Water Monitoring § 265.93 Preparation, evaluation, and response... an outline of a ground-water quality assessment program. The outline must describe a more comprehensive ground-water monitoring program (than that described in §§ 265.91 and 265.92) capable of...

  18. Student Evaluation of Audience Response Technology in Large Lecture Classes

    ERIC Educational Resources Information Center

    MacGeorge, Erina L.; Homan, Scott R.; Dunning, John B., Jr.; Elmore, David; Bodie, Graham D.; Evans, Ed; Khichadia, Sangeetha; Lichti, Steven M.; Feng, Bo; Geddes, Brian

    2008-01-01

    In the past few years, audience response technology (ART) has been widely adopted on college campuses, and is especially popular among instructors of large lecture classes. Claims regarding ART's benefits to students have received only limited empirical evaluation, and prior studies exhibit methodological limitations. The current study provides a…

  19. An Evaluation of Response Prompts for Teaching Behavior Chains

    ERIC Educational Resources Information Center

    Seaver, Jessica L.; Bourret, Jason C.

    2014-01-01

    Individuals who have been diagnosed with autism spectrum disorders can have difficulty acquiring new skills, and teaching procedures found to be efficient with 1 individual may not be efficient with others. However, relatively little research has evaluated methods to identify efficient, individualized response-prompt and prompt-fading procedures.…

  20. Evaluation of the Response to the Fukushima Accident.

    PubMed

    Miska, Horst

    2016-08-01

    The cause for the severity of the Fukushima nuclear accident is explained, and the radiological consequences are assessed. Moreover, the non-radiological effects are critically evaluated and failures in onsite and offsite emergency response highlighted. In conclusion, disregarding the principle of justification, the evacuation of residents and hospital patients was implemented too rigorously, resulting in unnecessary fatalities due to the protective action.

  1. Student Evaluation of Audience Response Technology in Large Lecture Classes

    ERIC Educational Resources Information Center

    MacGeorge, Erina L.; Homan, Scott R.; Dunning, John B., Jr.; Elmore, David; Bodie, Graham D.; Evans, Ed; Khichadia, Sangeetha; Lichti, Steven M.; Feng, Bo; Geddes, Brian

    2008-01-01

    In the past few years, audience response technology (ART) has been widely adopted on college campuses, and is especially popular among instructors of large lecture classes. Claims regarding ART's benefits to students have received only limited empirical evaluation, and prior studies exhibit methodological limitations. The current study provides a…

  2. Notification: OIG Evaluation of EPA's Response to Erroneous Laboratory Data

    EPA Pesticide Factsheets

    Project #OPE-FY12-0023, August 14, 2012. The purpose of this memorandum is to notify you that the Office of Inspector General (OIG) plans to begin preliminary.research on an evaluation of EPA's response to erroneous laboratory data.

  3. Evaluating Item Fit for Multidimensional Item Response Models

    ERIC Educational Resources Information Center

    Zhang, Bo; Stone, Clement A.

    2008-01-01

    This research examines the utility of the s-x[superscript 2] statistic proposed by Orlando and Thissen (2000) in evaluating item fit for multidimensional item response models. Monte Carlo simulation was conducted to investigate both the Type I error and statistical power of this fit statistic in analyzing two kinds of multidimensional test…

  4. Evaluating the Response of the Terrestrial Biosphere to Significant Drought

    NASA Astrophysics Data System (ADS)

    Shiach, I.; Baker, I. T.; Denning, A.

    2011-12-01

    The response of terrestrial fluxes of energy, water, and carbon to drought is evaluated. Major droughts should be clearly evident in reanalyzed precipitation data, although this is not always the case. With reduced precipitation we can expect a suppression in Gross Primary Photosynthesis (GPP) if physiological stress is sufficient, with atttendant changes in energy partitioning due to stomatal closure. There may also be a response in respiratory release of CO2 with temperature increase. This study aimed to investigate the behavior of the terrestrial biosphere using the Simple Biosphere Model (SiB3) during and following times of drought and to identify any model responses inconsistent with observational relationships. The Standardized Precipitation Index (SPI) was evaluated from 1983 to 2006 in order to evaluate historical drought maps, and to facilitate a qualitative analysis of modeled drought behavior. Standardized and raw anomaly maps were produced for modeled physiological variables (GPP, transpiration, respiration, heat fluxes, carbon flux, and stress factors) in order to determine general response patterns for comparison with observations. The SiB model was determined to be generally accurate in its representation of sign