WorldWideScience

Sample records for angiogenesis imaging methods

  1. Monitoring angiogenesis using magnetic resonance methods

    DEFF Research Database (Denmark)

    Holm, David Alberg

    2008-01-01

    When a tumor reaches a certain size it can no longer rely on passive perfusion for nutrition. The tumor therefore emits signaling molecules which stimulating surrounding vessels to divide and grow towards the tumor, a process known as angiogenesis. Very little angiogenesis is present in healthy...... adults where it is primaily found in wound healing, pregnancy and during the menstrual cycle. This thesis focus on the negative consequences of angiogenesis in cancer. It consists of a an initial overview followed by four manuscripts. The overview gives a short introduction to the process of angiogenesis...... and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti...

  2. PET imaging for evaluating tumor angiogenesis

    International Nuclear Information System (INIS)

    Angiogenesis, a main characteristic in tumors, plays an important role in tumor growth and metastasis, which provides a new strategy for tumor treatment. By marking angiogenesis-related receptors, polypeptides, kinases or extracellular matrix proteins as high affinity molecular probes, PET imaging can noninvasively display integrin, VEGF/VEGFR, matrix metalloproteinases (MMPs) and closely monitor tumor angiogenesis and vascular-targeted treatments on the molecular level. In this paper, research progress and future development of PET imaging for evaluating tumor angiogenesis are reviewed. (authors)

  3. Monitoring angiogenesis using magnetic resonance methods

    DEFF Research Database (Denmark)

    Holm, David Alberg

    2008-01-01

    When a tumor reaches a certain size it can no longer rely on passive perfusion for nutrition. The tumor therefore emits signaling molecules which stimulating surrounding vessels to divide and grow towards the tumor, a process known as angiogenesis. Very little angiogenesis is present in healthy a...... in a transgenic mouse model. The last manuscript presents a new method for in vivo cell labeling. This method could find use in studying the metastatic spread of cancer cells throughout the body....... and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti......-angiogenic treatment is presented in the first manuscript. In the second and third manuscript, two separate methods of quantifying perfusion, blood volume and vessel permeability are presented. The methods are used to show that drug delivery to a xenografted tumor is plausible and to show possible vascular maturation...

  4. Advances of molecular imaging in tumor angiogenesis

    International Nuclear Information System (INIS)

    Tumor angiogenesis has a close relationship with tumor growth, progression, metastasis and the prognosis of tumor patients. Therefore, tumor anti-angiogenic treatment arouses great public interest. Molecular imaging can characteristically display and measure the biochemical process of organisms at cellular and molecular level in vivo,which is based on the specific binding of molecular probe with high affinity and target molecules. In recent years, molecular imaging has a certain progress on visual and quantitative research of tumor angiogenesis and it is expected to become an important technique in the efficacy evaluation and prognostic assessment. This article summarizes the new advances of molecular imaging technology in tumor angiogenesis. (authors)

  5. Inorganic nanomaterials for tumor angiogenesis imaging

    International Nuclear Information System (INIS)

    Tumor angiogenesis plays an important role in cancer development and metastasis. Noninvasive detection of angiogenic activities is thus of great importance in cancer diagnosis as well as evaluation of cancer therapeutic responses. Various angiogenesis-related molecular targets have been identified and used in tumor vasculature targeting and imaging. Recently, inorganic nanomaterials with various unique intrinsic physical properties have attracted growing interest in biomedical imaging applications. This article will review current progresses in the applications of inorganic nanoprobes in molecular angiogenesis imaging. Several types of nanomaterials with various optical properties, including semiconductor quantum dots (QDs), single-walled carbon nanotubes (SWNTs), upconversion nanoparticles (UCNPs), and surface-enhanced Raman scattering (SERS) nanoparticles, have been used as novel optical probes to image angiogenic events. Besides optical imaging, magnetic resonance imaging (MRI) of angiogenesis using magnetic nanoparticles has also been intensively investigated. Moreover, nanomaterials provide unique platforms for the integration of various imaging modalities together with therapeutic functionalities for multi-modality imaging and therapy. Although the application of inorganic nanomaterials in clinical imaging and diagnosis is still facing many challenges, the unique properties and functions of these novel nanoprobes make them very promising agents in angiogenesis imaging and could bring great opportunities to this fast-growing field. (orig.)

  6. Optical techniques for the molecular imaging of angiogenesis

    International Nuclear Information System (INIS)

    The process of angiogenesis, an essential hallmark for tumour development as well as for several inflammatory diseases and physiological phenomena, is of growing interest for diagnosis and therapy in oncology. In the context of biochemical characterisation of key molecules involved in angiogenesis, several targets for imaging and therapy could be identified in the last decade. Optical imaging (OI) relies on the visualisation of near infrared (NIR) light, either its absorption and scattering in tissue (non-enhanced OI) or using fluorescent contrast agents. OI offers excellent signal to noise ratios due to virtually absent background fluorescence in the NIR range and is thus a versatile tool to image specific molecular target structures in vivo. This work intends to provide a survey of the different approaches to imaging of angiogenesis using OI methods in preclinical research as well as first clinical trials. Different imaging modalities as well as various optical contrast agents are briefly discussed. (orig.)

  7. Positron emission tomography tracers for imaging angiogenesis

    International Nuclear Information System (INIS)

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or αvβ3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging αvβ3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  8. Molecular imaging of angiogenesis with SPECT

    International Nuclear Information System (INIS)

    Single-photon emission computed tomography (SPECT) and position emission tomography (PET) are the two main imaging modalities in nuclear medicine. SPECT imaging is more widely available than PET imaging and the radionuclides used for SPECT are easier to prepare and usually have a longer half-life than those used for PET. In addition, SPECT is a less expensive technique than PET. Commonly used gamma emitters are: 99mTc (Emax 141 keV, T1/2 6.02 h), 123I (Emax 529 keV, T1/2 13.0 h) and 111In (Emax 245 keV, T1/2 67.2 h). Compared to clinical SPECT, PET has a higher spatial resolution and the possibility to more accurately estimate the in vivo concentration of a tracer. In preclinical imaging, the situation is quite different. The resolution of microSPECT cameras (1.5 mm). In this report, studies on new radiolabelled tracers for SPECT imaging of angiogenesis in tumours are reviewed. (orig.)

  9. Photoacoustic imaging of angiogenesis in subdermal islet transplant sites

    Science.gov (United States)

    Shi, Wei; Pawlick, Rena; Bruni, Antonio; Rafiei, Yasmin; Pepper, Andrew R.; Gala-Lopez, Boris; Choi, Min; Malcolm, Andrew; Zemp, Roger J.; Shapiro, A. M. James

    2016-03-01

    Exogenous insulin administration is the mainstay treatment therapy for patients with Type-1 diabetes mellitus (T1DM). However, for select patients, clinical islet transplantation is an alternative therapeutic treatment. In this procedure, islets are transplanted into the hepatic portal vein, and despite improved success within the last decade, obstacles are still associated with this approach. It has been discovered that the subcutaneous space may be an effective alternative site for islet transplantation, and may provide advantages of easy access and potential for simple monitoring. The ability to monitor islet viability and the transplant microenvironment may be key to future success in islet transplantation. A subcutaneous device-less technique has been developed to facilitate angiogenesis in the islet transplant site, however, a method for monitoring the potential engraftment site have yet to be explored fully. Here we demonstrate the ability to track angiogenesis in mice with 1, 2, 3 and 4 weeks post-catheter implant on both sides of the abdomen using a FujiFilm VisualSonics Vevo-LAZR system. Quantitative analysis on vessel densities exhibited gradual vessel growth successfully induced by catheter implantation. Our study demonstrates the ability of employing photoacoustic and micro-ultrasound imaging to track angiogenesis around the catheter site prior to islet transplantation.

  10. Automated angiogenesis quantification through advanced image processing techniques.

    Science.gov (United States)

    Doukas, Charlampos N; Maglogiannis, Ilias; Chatziioannou, Aristotle; Papapetropoulos, Andreas

    2006-01-01

    Angiogenesis, the formation of blood vessels in tumors, is an interactive process between tumor, endothelial and stromal cells in order to create a network for oxygen and nutrients supply, necessary for tumor growth. According to this, angiogenic activity is considered a suitable method for both tumor growth or inhibition detection. The angiogenic potential is usually estimated by counting the number of blood vessels in particular sections. One of the most popular assay tissues to study the angiogenesis phenomenon is the developing chick embryo and its chorioallantoic membrane (CAM), which is a highly vascular structure lining the inner surface of the egg shell. The aim of this study was to develop and validate an automated image analysis method that would give an unbiased quantification of the micro-vessel density and growth in angiogenic CAM images. The presented method has been validated by comparing automated results to manual counts over a series of digital chick embryo photos. The results indicate the high accuracy of the tool, which has been thus extensively used for tumor growth detection at different stages of embryonic development. PMID:17946107

  11. Quantum dots for multimodal molecular imaging of angiogenesis

    OpenAIRE

    Mulder, W.J.M.; Strijkers, G.J.; Nicolay, K.; Griffioen, A W

    2010-01-01

    Quantum dots exhibit unique optical properties for bioimaging purposes. We have previously developed quantum dots with a paramagnetic and functionalized coating and have shown their potential for molecular imaging purposes. In the current mini-review we summarize the synthesis procedure, the in vitro testing and, importantly, the in vivo application for multimodal molecular imaging of tumor angiogenesis.

  12. In Vivo Tumor Angiogenesis Imaging Using Peptide-Based Near-Infrared Fluorescent Probes.

    Science.gov (United States)

    Huang, Rui; Conti, Peter S; Chen, Kai

    2016-01-01

    Near-infrared fluorescence (NIRF) imaging is an emerging imaging technique for studying diseases at the molecular level. Optical imaging with a near-infrared emitting fluorophore for targeting tumor angiogenesis offers a noninvasive method for early tumor detection and efficient monitoring of tumor response to anti-angiogenesis therapy. CD13 receptor, a zinc-dependent membrane-bound ectopeptidase, plays important roles in regulating tumor angiogenesis and the growth of new blood vessels. In this chapter, we use CD13 receptor as an example to demonstrate how to construct CD13-specific NGR-containing peptides via bioorthogonal click chemistry for visualizing and quantifying the CD13 receptor expression in vivo by means of NIRF optical imaging. PMID:27283419

  13. Lung cancer and angiogenesis imaging using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiaoxia; Zhao Jun; Xu, Lisa X [Biomedical Engineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai (China); Sun Jianqi; Gu Xiang; Liu Ping [Med-X Research Institute, Shanghai Jiao Tong University, Shanghai (China); Xiao Tiqiao [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai (China)], E-mail: pingliu@sjtu.edu.cn, E-mail: lisaxu@sjtu.edu.cn

    2010-04-21

    Early detection of lung cancer is the key to a cure, but a difficult task using conventional x-ray imaging. In the present study, synchrotron radiation in-line phase-contrast imaging was used to study lung cancer. Lewis lung cancer and 4T1 breast tumor metastasis in the lung were imaged, and the differences were clearly shown in comparison to normal lung tissue. The effect of the object-detector distance and the energy level on the phase-contrast difference was investigated and found to be in good agreement with the theory of in-line phase-contrast imaging. Moreover, 3D image reconstruction of lung tumor angiogenesis was obtained for the first time using a contrast agent, demonstrating the feasibility of micro-angiography with synchrotron radiation for imaging tumor angiogenesis deep inside the body.

  14. Lung cancer and angiogenesis imaging using synchrotron radiation

    Science.gov (United States)

    Liu, Xiaoxia; Zhao, Jun; Sun, Jianqi; Gu, Xiang; Xiao, Tiqiao; Liu, Ping; Xu, Lisa X.

    2010-04-01

    Early detection of lung cancer is the key to a cure, but a difficult task using conventional x-ray imaging. In the present study, synchrotron radiation in-line phase-contrast imaging was used to study lung cancer. Lewis lung cancer and 4T1 breast tumor metastasis in the lung were imaged, and the differences were clearly shown in comparison to normal lung tissue. The effect of the object-detector distance and the energy level on the phase-contrast difference was investigated and found to be in good agreement with the theory of in-line phase-contrast imaging. Moreover, 3D image reconstruction of lung tumor angiogenesis was obtained for the first time using a contrast agent, demonstrating the feasibility of micro-angiography with synchrotron radiation for imaging tumor angiogenesis deep inside the body.

  15. Assessment methods for angiogenesis and current approaches for its quantification.

    Science.gov (United States)

    AlMalki, Waleed Hassan; Shahid, Imran; Mehdi, Abeer Yousaf; Hafeez, Muhammad Hassan

    2014-01-01

    Angiogenesis is a physiological process which describes the development of new blood vessels from the existing vessels. It is a common and the most important process in the formation and development of blood vessels, so it is supportive in the healing of wounds and granulation of tissues. The different assays for the evaluation of angiogenesis have been described with distinct advantages and some limitations. In order to develop angiogenic and antiangiogenic techniques, continuous efforts have been resulted to give animal models for more quantitative analysis of angiogenesis. Most of the studies on angiogenic inducers and inhibitors rely on various models, both in vitro, in vivo and in ova, as indicators of efficacy. The angiogenesis assays are very much helpful to test efficacy of both pro- and anti- angiogenic agents. The development of non-invasive procedures for quantification of angiogenesis will facilitate this process significantly. The main objective of this review article is to focus on the novel and existing methods of angiogenesis and their quantification techniques. These findings will be helpful to establish the most convenient methods for the detection, quantification of angiogenesis and to develop a novel, well tolerated and cost effective anti-angiogenic treatment in the near future. PMID:24987169

  16. Diversity of radioprobes targeted to tumor angiogenesis on molecular functional imaging

    International Nuclear Information System (INIS)

    Molecular functional imaging could visualize, characterize, and measure the bio- logical processes including tumor angiogenesis at the molecular and cellular levels in humans and other living systems. The molecular probes labeled by a variety of radionuclide used in the field of the nuclear medicine play pivotal roles in molecular imaging of tumor angiogenesis. However, the regulatory role of different probes in tumor angiogenesis has not been systematically illustrated. The current status of tumor angiogenesis imaging with radiolabeled probes of peptide, monoclonal antibody as well as its fragment, especially nanoparticle-based probes to gain insights into the robust tumor angiogenesis development were summarized. It was recognized that only the probes such as nanoparticle-based probes, which truly target the tumor vasculature rather than tumor cells because of poor extravasation, are really tumor angiogenesis imaging agent. The research of molecular probe targeted to angiogenesis would meet its flourish just after the outstanding improvements in the in vivo stability and biocompatibility, tumor-targeting efficacy, and pharmacokinetics of tumor angiogenesis imaging probes are made. Translation to clinical applications will also be critical for the maximize benefits of these novel agents. The future of tumor angiogenesis imaging lies in liable imaging probes and multiple imaging modalities, imaging of protein-protein interactions, and quantitative molecular imaging. (authors)

  17. Narrow-band imaging endoscopy to assess mucosal angiogenesis in inflammatory bowel disease: A pilot study

    Institute of Scientific and Technical Information of China (English)

    Silvio; Danese; Gionata; Fiorino; Erika; Angelucci; Stefania; Vetrano; Nico; Pagano; Giacomo; Rando; Antonino; Spinelli; Alberto; Malesci; Alessandro; Repici

    2010-01-01

    AIM: To investigate whether narrow band imaging (NBI) is a useful tool for the in vivo detection of angiogenesis in inflammatory bowel disease (IBD) patients. METHODS: Conventional and NBI colonoscopy was performed in 14 patients with colonic inflammation (8 ulcerative colitis and 6 Crohn’s disease). Biopsy samples were taken and CD31 expression was assayed immuno- histochemically; microvascular density was assessed by vessel count. RESULTS: In areas that were endoscopically normal but positive on NBI, ther...

  18. Tumour angiogenesis pathways: related clinical issues and implications for nuclear medicine imaging

    International Nuclear Information System (INIS)

    Tumour angiogenesis is essential for growth, invasion and metastasis. Retrospective studies suggest that it is an independent prognostic factor that merits prospective validation. Furthermore, as tumour blood vessels show many differences from normal vessels and are not genetically unstable, they form a key area for therapy development. However, as anti-angiogenic therapy is primarily cytostatic and not cytotoxic, novel tailor-made specific end-points for treatment monitoring are required. In this regard, suitable molecular parameters for imaging tumour angiogenesis by means of nuclear medicine are being explored. Here we review current knowledge on the multiple pathways controlling tumour angiogenesis and try to assess which are the most clinically relevant for nuclear medicine imaging. Parameters that may influence the imaging potential of radiopharmaceuticals for angiogenesis imaging such as molecular weight and structure, their targeted location within the tumour and their usefulness in terms of specificity and constancy of the targeted molecular pathway are discussed. (orig.)

  19. Imaging techniques used for the real-time assessment of angiogenesis in digestive cancers

    DEFF Research Database (Denmark)

    Săftoiu, Adrian; Vilmann, Peter

    2011-01-01

    Angiogenesis has a critical role in primary tumor growth and the development of metastases. Several angiogenesis inhibitors were recently developed, being a very attractive target for digestive tumor therapy. However, individualized therapy should not only be based on the pre-treatment imaging...... evaluation, but also on sensitive monitoring of microvascular changes during treatment. State-of-the-art imaging techniques have the potential to visualize and characterize angiogenesis, although the technology and methodologies employed are recent and need further validation. The aim of this series of...... reviews was to analyze and enhance current knowledge and future perspectives about the real-time assessment of angiogenesis in digestive cancers, used for the longitudinal monitoring of the effects of chemo-radiotherapy (including anti-angiogenic therapies), as well as for the precise targeting of drugs...

  20. Preliminary study on application of synchrotron radiation imaging to tumor angiogenesis

    International Nuclear Information System (INIS)

    Angiogenesis plays an important role in tumor growth and metastasis. However, only vessels lager than 200 μm in diameter can be observed using conventional medical image. Synchrotron radiation(SR) phase contrast imaging, with a spatial resolution being as high as 1 μm, has great advantages in imaging soft tissue structure, such as blood vessels and tumors. The morphology of tumor angiogenesis at different stages in the 4T1 nude mice tumor window model was firstly studied without contrast agent using the SR phase contrast imaging at SSRF X-ray imaging and biomedical application beamline. The results showed dense, irregular and tortuous tumor angiogenesis with the smallest vessels of 20-30 μm in diameter. (authors)

  1. MR imaging of tumor angiogenesis using sterically stabilized Gd-DTPA liposomes targeted to CD105

    International Nuclear Information System (INIS)

    Aim: To depict tumor angiogenesis via the expression of CD105 in tumor-bearing rats using Gd-DTPA liposomes targeted to CD105 (CD105-Gd-SLs) on MR imaging. Materials and methods: Three Gd-DTPA liposomal nanoparticles were prepared in our trial: liposomes entrapping Gd-DTPA (Gd-SLs), Gd-SLs conjugated to immunoglobulins (IgG-Gd-SLs) and CD105-Gd-SLs. Forty glioma-bearing rats were randomized into four groups: (a) Gd-DTPA; (b) Gd-SLs; (c) IgG-Gd-SLs; (d) CD105-Gd-SLs. Axial T1WI MRI images were collected at baseline and repeated at 5, 30, 60 and 120 min post-intravenous injection of Gd-DTPA or liposome. Enhancement features and contrast-to-noise ratio of each group were analyzed. After imaging, tumors were resected for immunohistochemistry and immunofluorescence staining to assess vascularity and angiogenesis. Results: The four groups showed different enhancement features. The enhancement area was restricted for group CD105-Gd-SLs, while diffused for the other three. The degree of enhancement over time varied: group Gd-DTPA showed an early contrast enhancement at instant after injection with a peak at 30 min and a decline to baseline values at 60 min. In group CD105-Gd-SLs, the signal intensity (SI) continuously increased over 120 min. In groups IgG-Gd-SLs and Gd-SLs the SI peaked at 60 min, followed by a minor decrease for IgG-Gd-SLs and a rapid decrease for Gd-SLs almost to baseline. Immunohistochemistry and immunofluorescence showed that the enhancement in the CD105-Gd-SLs group resulted mainly from new microvessels. While in the other three groups, mature microvessels and new microvasculature resulted in the enhancement of the tumor. Conclusion: CD105-Gd-SLs can be used to detect early tumor angiogenesis on MR images. This might provide a means to non-invasively reveal a malignant phenotype of extracerebral F98 tumor and evaluate its progression.

  2. Spatiotemporal Analyses of Osteogenesis and Angiogenesis via Intravital Imaging in Cranial Bone Defect Repair.

    Science.gov (United States)

    Huang, Chunlan; Ness, Vincent P; Yang, Xiaochuan; Chen, Hongli; Luo, Jiebo; Brown, Edward B; Zhang, Xinping

    2015-07-01

    Osteogenesis and angiogenesis are two integrated components in bone repair and regeneration. A deeper understanding of osteogenesis and angiogenesis has been hampered by technical difficulties of analyzing bone and neovasculature simultaneously in spatiotemporal scales and in 3D formats. To overcome these barriers, a cranial defect window chamber model was established that enabled high-resolution, longitudinal, and real-time tracking of angiogenesis and bone defect healing via multiphoton laser scanning microscopy (MPLSM). By simultaneously probing new bone matrix via second harmonic generation (SHG), neovascular networks via intravenous perfusion of fluorophore, and osteoblast differentiation via 2.3-kb collagen type I promoter-driven GFP (Col2.3GFP), we examined the morphogenetic sequence of cranial bone defect healing and further established the spatiotemporal analyses of osteogenesis and angiogenesis coupling in repair and regeneration. We showed that bone defect closure was initiated in the residual bone around the edge of the defect. The expansion and migration of osteoprogenitors into the bone defect occurred during the first 3 weeks of healing, coupled with vigorous microvessel angiogenesis at the leading edge of the defect. Subsequent bone repair was marked by matrix deposition and active vascular network remodeling within new bone. Implantation of bone marrow stromal cells (BMSCs) isolated from Col2.3GFP mice further showed that donor-dependent bone formation occurred rapidly within the first 3 weeks of implantation, in concert with early angiogenesis. The subsequent bone wound closure was largely host-dependent, associated with localized modest induction of angiogenesis. The establishment of a live imaging platform via cranial window provides a unique tool to understand osteogenesis and angiogenesis in repair and regeneration, enabling further elucidation of the spatiotemporal regulatory mechanisms of osteoprogenitor cell interactions with host bone

  3. Tumor angiogenesis in rabbit VX2 brain tumor: model establishment, pathologic study and preliminary imaging observation

    International Nuclear Information System (INIS)

    Objective: To establish a stable implanted model of VX2 rabbit brain tumor, and to evaluate the pathological and imaging features and tumor angiogenesis. Methods: Thirty New Zealand white rabbits were implanted with 100 μl viable VX2 tumor cells (107/ml) through a hole 5 mm to the right of the sagittal suture and 5 mm posterior to the coronal suture bored by a dental drill. MRI was performed every 2 days after 7 days of implantation to evaluate the growth of the tumor, and perfusion CT studies were performed in different days of tumor growth. After that the animals were sacrificed on days 14, 18, 22, 26, and 30 of tumor implantation. 2% Evans blue (2 ml/kg) was given intravenously in 16 of these animals 1 hour prior to sacrifice to detect the breakdown of the blood-brain barrier (BBB). The specimens of the rabbit brains were examined pathologically and histologically. VEGF and MVD were evaluated in immunohistochemical examination. Results: Of the 22 animals included into the study, the tumor grew in 20 animals, which could be seen clearly on MR imaging. Pathologic examination showed characteristics of squamous carcinoma. VEGF was expressed in all tumors with the mean rate of positive cells of (52.51 ± 19.15)% (19.5%-92.9%). Mean MVD was (51.30 ± 14.42) pice piece/microscope (25-81 pice piece/microscope). Using Pearson's linear correlation analysis, positive correlation was found between tumor growth time and volume (r=0.791, P=0.000), between MVD and tumor growth time (r=0.875, P=0.000), and between MVD and tumor volume (r=0.901, P=0.000), respectively. Spearman's rank correlation analysis showed positive correlation between VEGF grade and blue stain of the tumor (rs=0.594, P=0.015). Conclusion: A stable model of VX2 rabbit brain tumor has been established with the method of skull drilling. The method was simple and easy to use, with a high tumor growth rate and remarkable angiogenesis. The model is helpful for the pathological and radiological study of tumor

  4. The application of CD13/aminopeptidase N in the angiogenesis imaging

    International Nuclear Information System (INIS)

    The development and metasis of malignant tumor depend on neovascularization. CD 13 is a significant marker of cells commit to myeloid lineage to classify leukemia, meanwhile it expresses on the neovascular endothelial cells specifically but expresses barely in vascular endothelial cells. Coupling CD13 monoclonal antibody or CD13 ligand to CD13 in fluorescence, radionuclide or magnetic nanoparticles to achieve molecular imaging to probe angiogenesis and provide imaging evidence of the development of angiogenesis associated disease. Asn-Gly-Arg peptide motif compound with different anticancer drugs targeted deliver to neovascular endothelial cells and release the anticancer drugs to treat the tumor. The research of CD13 to understand, diagnose and treat the angiogenesis associated diseases has gotten breakthrough and have a promising future. (authors)

  5. In vivo laser speckle imaging reveals microvascular remodeling and hemodynamic changes during wound healing angiogenesis

    OpenAIRE

    Rege, Abhishek; Thakor, Nitish V; Rhie, Kevin; Pathak, Arvind P.

    2011-01-01

    Laser speckle contrast imaging (LSCI) is a high-resolution and high contrast optical imaging technique often used to characterize hemodynamic changes in short-term physiological experiments. In this study, we demonstrate the utility of LSCI for characterizing microvascular remodeling and hemodynamic changes during wound healing angiogenesis in vivo. A 2 mm diameter hole was made in the mouse ear and the periphery of the wound imaged in vivo using LSCI over 12 days. We were able to visualize a...

  6. Imaging techniques used for the real-time assessment of angiogenesis in digestive cancers

    DEFF Research Database (Denmark)

    Saftoiu, Adrian; Vilmann, Peter; Săftoiu, Adrian

    2011-01-01

    evaluation, but also on sensitive monitoring of microvascular changes during treatment. State-of-the-art imaging techniques have the potential to visualize and characterize angiogenesis, although the technology and methodologies employed are recent and need further validation. The aim of this series of...... reviews was to analyze and enhance current knowledge and future perspectives about the real-time assessment of angiogenesis in digestive cancers, used for the longitudinal monitoring of the effects of chemo-radiotherapy (including anti-angiogenic therapies), as well as for the precise targeting of drugs...

  7. Grating-based phase-contrast imaging of tumor angiogenesis in lung metastases.

    Directory of Open Access Journals (Sweden)

    Huimin Lin

    Full Text Available To assess the feasibility of the grating-based phase-contrast imaging (GPI technique for studying tumor angiogenesis in nude BALB/c mice, without contrast agents.We established lung metastatic models of human gastric cancer by injecting the moderately differentiated SGC-7901 gastric cancer cell line into the tail vein of nude mice. Samples were embedded in a 10% formalin suspension and dried before imaging. Grating-based X-ray phase-contrast images were obtained at the BL13W beamline of the Shanghai Synchrotron Radiation Facility (SSRF and compared with histological sections.Without contrast agents, grating-based X-ray phase-contrast imaging still differentiated angiogenesis within metastatic tumors with high spatial resolution. Vessels, down to tens of microns, showed gray values that were distinctive from those of the surrounding tumors, which made them easily identifiable. The vessels depicted in the imaging study were similar to those identified on histopathology, both in size and shape.Our preliminary study demonstrates that grating-based X-ray phase-contrast imaging has the potential to depict angiogenesis in lung metastases.

  8. Angiogenesis imaging with vascular-constrained particles: the why and how

    International Nuclear Information System (INIS)

    Angiogenesis is a keystone in the treatment of cancer and potentially many other diseases. In cancer, first-generation antiangiogenic therapeutic approaches have demonstrated survival benefit in subsets of patients, but their high cost and notable adverse side effect risk have fueled alternative development efforts to personalize patient selection and reduce off-target effects. In parallel, rapid advances in cost-effective genomic profiling and sensitive early detection of high-risk biomarkers for cancer, atherosclerosis, and other angiogenesis-related pathologies will challenge the medical imaging community to identify, characterize, and risk stratify patients early in the natural history of these disease processes. Conventional diagnostic imaging techniques were not intended for such sensitive and specific detection, which has led to the emergence of novel noninvasive biomedical imaging approaches. The overall intent of molecular imaging is to achieve greater quantitative characterization of pathologies based on microanatomical, biochemical, or functional assessments; in many approaches, the capacity to deliver effective therapy, e.g., antiangiogenic therapy, can be combined. Agents with both diagnostic and therapy attributes have acquired the moniker ''theranostics.'' This review will explore biomedical imaging options being pursued to better segment and treat patients with angiogenesis-influenced disease using vascular-constrained contrast platform technologies. (orig.)

  9. Hemodynamic response imaging: a potential tool for the assessment of angiogenesis in brain tumors.

    Directory of Open Access Journals (Sweden)

    Dafna Ben Bashat

    Full Text Available 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.

  10. Angiogenesis Imaging Using (68)Ga-RGD PET/CT: Therapeutic Implications.

    Science.gov (United States)

    Eo, Jae Seon; Jeong, Jae Min

    2016-09-01

    Angiogenesis imaging is important for diagnostic and therapeutic treatment of various malignant and nonmalignant diseases. The Arg-Gly-Asp (RGD) sequence has been known to bind with the αvβ3 integrin that is expressed on the surface of angiogenic blood vessels or tumor cells. Thus, various radiolabeled derivatives of RGD peptides have been developed for angiogenesis imaging. Among the various radionuclides, (68)Ga was the most widely studied for RGD peptide imaging because of its excellent nuclear physical properties, easy-to-label chemical properties, and cost-effectiveness owing to the availability of a (68)Ge-(68)Ga generator. Thus, various (68)Ga-labeled RGD derivatives have been developed and applied for preclinical and clinical studies. Clinical trials were performed for both malignant and nonmalignant diseases. Breast cancer, glioma, and lung cancer were malignant, and myocardial infarction, atherosclerosis, and moyamoya disease were nonmalignant among the investigated diseases. Further, these (68)Ga-labeled RGD derivatives could be applied to assess the effects of antiangiogenic treatment or theragnosis or both, of cancers. In conclusion, the angiogenesis imaging technology using (68)Ga-labeled RGD derivatives might be useful for the development of new therapeutic assessments, and for diagnostic and theragnostic applications. PMID:27553467

  11. Photoacoustic imaging of angiogenesis in a subcutaneous islet transplant site in a murine model

    Science.gov (United States)

    Shi, Wei; Pawlick, Rena; Bruni, Antonio; Rafiei, Yasmin; Pepper, Andrew R.; Gala-Lopez, Boris; Choi, Min; Malcolm, Andrew; Zemp, Roger J.; Shapiro, A. M. James

    2016-06-01

    Islet transplantation (IT) is an established clinical therapy for select patients with type-1 diabetes. Clinically, the hepatic portal vein serves as the site for IT. Despite numerous advances in clinical IT, limitations remain, including early islet cell loss posttransplant, procedural complications, and the inability to effectively monitor islet grafts. Hence, alternative sites for IT are currently being explored, with the subcutaneous space as one potential option. When left unmodified, the subcutaneous space routinely fails to promote successful islet engraftment. However, when employing the previously developed subcutaneous "deviceless" technique, a favorable microenvironment for islet survival and function is established. In this technique, an angiocatheter was temporarily implanted subcutaneously, which facilitated angiogenesis to promote subsequent islet engraftment. This technique has been employed in preclinical animal models, providing a sufficient means to develop techniques to monitor functional aspects of the graft such as angiogenesis. Here, we utilize photoacoustic imaging to track angiogenesis during the priming of the subcutaneous site by the implanted catheter at 1 to 4 weeks postcatheter. Quantitative analysis on vessel densities shows gradual growth of vasculature in the implant position. These results demonstrate the ability to track angiogenesis, thus facilitating a means to optimize and assess the pretransplant microenvironment.

  12. Development of 68Ga-Glycopeptide as an Imaging Probe for Tumor Angiogenesis

    Directory of Open Access Journals (Sweden)

    Ning Tsao

    2011-01-01

    Full Text Available Objective. This study was aimed to study tissue distribution and tumor imaging potential of 68Ga-glycopeptide (GP in tumor-bearing rodents by PET. Methods. GP was synthesized by conjugating glutamate peptide and chitosan. GP was labeled with 68Ga chloride for in vitro and in vivo studies. Computer outlined region of interest (counts per pixel of the tumor and muscle (at the symmetric site was used to determine tumor-to-muscle count density ratios. To ascertain the feasibility of 68Ga-GP in tumor imaging in large animals, PET/CT imaging of 68Ga-GP and 18F-FDG were conducted in New Zealand white rabbits bearing VX2 tumors. Standard uptake value of tumors were determined by PET up to 45 min. To determine blood clearance and half-life of 68Ga-GP, blood samples were collected from 10 seconds to 20 min. Results. Radiochemical purity of 68Ga-GP determined by instant thin-layer chromatography was >95%. Tumor uptake values (SUV for 68Ga-GP and 18F-FDG in New Zealand white rabbits bearing VX2 tumors were 3.25 versus 7.04. PET images in tumor-bearing rats and rabbits confirmed that 68Ga-GP could assess tumor uptake. From blood clearance curve, the half-life of 68Ga-GP was 1.84 hr. Conclusion Our data indicate that it is feasible to use 68Ga-GP to assess tumor angiogenesis.

  13. Micro-CT molecular imaging of tumor angiogenesis using a magnetite nano-cluster probe.

    Science.gov (United States)

    Liu, Ping; Li, Jing; Zhang, Chunfu; Xu, Lisa X

    2013-06-01

    Due to its high resolution, micro-CT is desirable for molecular imaging of tumor angiogenesis. However, the sensitivity of micro-CT to contrast agents is relatively low. Therefore, the purpose of this study is to develop high micro-CT sensitive molecular imaging probes for direct visualization and dynamic monitoring of tumor angiogenesis. To this end, Arg-Gly-Asp (RGD) peptides conjugated magnetite nano clusters (RGD-MNCs) were developed by assembling individual magnetite nano particles into clusters with amphiphilic (maleimide) methoxypoly(ethylene glycol)-b-poly(lactic acid) ((Mal)mPEG-PLA) copolymer and subsequently encoding RGD peptides onto the clusters for specific targeting alpha(v)beta3 integrin. The hydrodynamic size of RGD-MNCs was about 85 nm. To test its specificity, alpha(v)beta3 positive cells (H1299) were incubated with magnetite nano clusters (MNCs), RGD-MNCs or RGD-MNCs competition with free RGD peptides. Prussian Blue staining and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements indicated that the cell uptake of RGD-MNCs was significantly more than that of MNCs, which could be inhibited by free RGD peptides. For detection of tumor angiogenesis, mice bearing H1299 tumors were injected intravenously with RGD-MNCs at the dose of 400 micro mol Fe/kg. Tumor angiogenic hot spots as well as individual angiogenic vessels could be clearly manifested by micro-CT imaging 12 h post injection, which was dynamically monitored with the extension of probe circulation time. Subsequent histological studies of tumor tissues verified that RGD-MNCs registered tumor angiogenic vessels. Our study demonstrated that RGD-MNC probes fabricated in this study could be used to effectively target alpha(v)beta3 integrin. Using high resolution micro-CT in combination with the probes, tumor angiogenesis could be studied dynamically. PMID:23858968

  14. Radiolabeled RGD peptides as tumor angiogenesis markers: from molecular imaging to targeted therapy

    International Nuclear Information System (INIS)

    Integrin ανβ3 plays a significant role in tumor angiogenesis which is one of the key requirements for cancer growth. During the past two decades, a number of radiolabeled linear and cyclic RGD peptide derivatives have been evaluated as integrin ανβ3-targeting radiotracers for detection and prognosis of cancer by SPECT and PET imaging. However, there is a continuing need for more efficient integrin ανβ3 -targeted radiotracers that could be readily prepared from a kit formulation without further post-labeling purification. The present article gives a brief overview of the fundamental aspects in the design and development of ideal radiotracers for targeting tumor angiogenesis based on RGD peptides. (author)

  15. In Vivo Photoacoustic Tomography of Total Blood Flow and Potential Imaging of Cancer Angiogenesis and Hypermetabolism

    OpenAIRE

    Yao, Junjie; Maslov, Konstantin I.; Wang, Lihong V.

    2012-01-01

    Blood flow is a key parameter in studying cancer angiogenesis and hypermetabolism. Current photoacoustic blood flow estimation methods focus on either the axial or transverse component of the flow vector. However, the Doppler angle (beam-to-flow angle) is needed to calculate the total flow speed, and it cannot always be estimated accurately in practice, especially when the system's axial and lateral resolutions are different. To overcome this problem, we propose a method to compute the total ...

  16. Molecular imaging of tumor angiogenesis with VEGFR2 targeting microbubbles in colon cancer bearing nude mice

    International Nuclear Information System (INIS)

    Objective: To evaluate the effect of tumor neovascularization imaging in a nude mouse model of colon cancer by contrast ultrasound molecular imaging (UMI) of VEGF receptor 2 (kinase insert domain receptor, KDR). Methods: Targeted microbubbles (MBt) were built by conjugating K237, a small peptide with high affinity for KDR, to liposome microbubbles through a biotin-avidin bridge. Control microbubbles (MBc) with control peptide were prepared by the same method. Nude mice models of LS174T human colon cancer were established. MBt and MBc were injected intravenously in twelve mice in random order with an interval of 30 min. MBt were injected in another six mice after K237-peptide blocking. UMI was performed in all mice at 5 min postinjection to observe the imaging difference and measure the video intensity (Ⅵ) of tumor tissues in different groups. One-way analysis of variance and the least significant difference t test were performed to analyze the difference of tumor Ⅵ in the groups with MBt, MBc and K237 blocking. Immunohistochemistry was applied to detect the expression and distribution of KDR in tumor tissue and adjacent tumor tissues. Results: K237 peptide was successfully conjugated to the surface of microbubbles through biotin-avidin mediation. Ultrasound imaging signal of the tumor was high in the MBt group, while there were no significant enhancement in the groups of K237 blocking and MBc. The Ⅵ in MBt, MBc and K237 blocking groups was significantly different (F=39.130, P<0.01). There was a significant difference of Ⅵ in the MBt group compared to the MBc group (30.18 ± 9.56 vs 8.28 ± 4.74, t=6.91, P<0.01). In the K237 blocking group Ⅵ was significantly lower than that in the MBt group (9.23 ± 3.44 vs 30.18 ± 9.56, t=4.91, P<0.01). Immunohistochemistry results showed that KDR was highly expressed in tumor tissue. Conclusions: KDR-targeting liposome contrast microbubbles may specifically and efficiently link to tumor vascular endothelial cells in

  17. {sup 18}F-labeled RGD peptide: initial evaluation for imaging brain tumor angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xiaoyuan; Park, Ryan; Shahinian, Anthony H.; Tohme, Michel; Khankaldyyan, Vazgen; Bozorgzadeh, Mohammed H.; Bading, James R.; Moats, Rex; Laug, Walter E.; Conti, Peter S. E-mail: pconti@usc.edu

    2004-02-01

    Brain tumors are highly angiogenesis dependent. The cell adhesion receptor integrin {alpha}{sub v}{beta}{sub 3} is overexpressed in glioma and activated endothelial cells and plays an important role in brain tumor growth, spread and angiogenesis. Suitably labeled {alpha}{sub v}{beta}{sub 3}-integrin antagonists may therefore be useful for imaging brain tumor associated angiogenesis. Cyclic RGD peptide c(RGDyK) was labeled with {sup 18}F via N-succinimidyl-4-[{sup 18}F]fluorobenzoate through the side-chain {epsilon}-amino group of the lysine residue. The radiotracer was evaluated in vivo for its tumor targeting efficacy and pharmacokinetics in subcutaneously implanted U87MG and orthotopically implanted U251T glioblastoma nude mouse models by means of microPET, quantitative autoradiography and direct tissue sampling. The N-4-[{sup 18}F]fluorobenzoyl-RGD ([{sup 18}F]FB-RGD) was produced in less than 2 h with 20-25% decay-corrected yields and specific activity of 230 GBq/{mu}mol at end of synthesis. The tracer showed very rapid blood clearance and both hepatobiliary and renal excretion. Tumor-to-muscle uptake ratio at 30 min was approximately 5 in the subcutaneous U87MG tumor model. MicroPET imaging with the orthotopic U251T brain tumor model revealed very high tumor-to-brain ratio, with virtually no uptake in the normal brain. Successful blocking of tumor uptake of [{sup 18}F]FB-RGD in the presence of excess amount of c(RGDyK) revealed receptor specific activity accumulation. Hence, N-4-[{sup 18}F]fluorobenzoyl labeled cyclic RGD peptide [{sup 18}F]FB-RGD is a potential tracer for imaging {alpha}{sub v}{beta}{sub 3}-integrin positive tumors in brain and other anatomic locations.

  18. Positron Emission Tomography Imaging of Tumor Angiogenesis with a 66Ga-Labeled Monoclonal Antibody

    OpenAIRE

    Engle, Jonathan W.; Hong, Hao; Zhang, Yin; Valdovinos, Hector F.; Myklejord, Duane V.; Barnhart, Todd E.; Theuer, Charles P.; Robert J. Nickles; Cai, Weibo

    2012-01-01

    The goal of this study was to develop a 66Ga-based positron emission tomography (PET) tracer for non-invasive imaging of CD105 expression during tumor angiogenesis, a hallmark of cancer. 66Ga was produced using a cyclotron with natZn or isotopically enriched 66Zn targets. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 2-S-(4-isothiocyanatobenzyl)-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (p-SCN-Bn-NOTA) and labeled with 66Ga. No difference in CD105 binding affinit...

  19. 肿瘤血管生成的影像学评价及新进展%Imaging assessment and trends of tumor angiogenesis

    Institute of Scientific and Technical Information of China (English)

    刘丽

    2012-01-01

    肿瘤的生长和转移依赖于血管生成.抑制肿瘤血管形成是继外科手术、放化疗之后肿瘤治疗的新的有效手段.许多临床前抗血管生成治疗动物试验显示出很好的前景,但是在临床应用中的疗效却不够满意,其原因有待深入探讨.如何在活体上无创评价肿瘤血管生成和抗肿瘤血管生成治疗的效果是目前肿瘤学研究的热点之一.文中介绍利用显微光学成像、超声成像、CT、MRI、核医学、分子影像、多模式成像等成像方法对肿瘤血管生成的研究及进展.%The development and metastasis of solid tumor require angiogenesis to get oxygen and nutrients. Inhibition of tumor angiogenesis is another effective means following surgery, radiotherapy and chemotherapy. Anti-angiogenic therapy in many preclinical animal tests show good prospects, but their deviation of the clinical efficacy call for in-depth studies. Of them in vivo noninvasive evaluation of tumor angiogenesis and anti-angiogenic effect is currently one of the hot-points. This article describes the use of optical microscopy imaging, ultrasound imaging, MRI, CT, nuclear medicine, molecular imaging, multi-mode imaging and other imaging methods in tumor angiogenesis and their progress.

  20. Breast imaging technology: Application of magnetic resonance imaging to angiogenesis in breast cancer

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) techniques enable vascular function to be mapped with high spatial resolution. Current methods for imaging in breast cancer are described, and a review of recent studies that compared dynamic contrast-enhanced MRI with histopathological indicators of tumour vascular status is provided. These studies show correlation between in vivo dynamic contrast measurements and in vitro histopathology. Dynamic contrast enhanced MRI is also being applied to assessment of the response of breast tumours to treatment

  1. Breast Lesions: Correlation of Dynamic Contrast Enhancement Patterns on MR images with Tumor Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    PeifangLiu; RunxianBao; YunNiu; YongYu

    2004-01-01

    OBJECTIVE To determine whether dynamic contrast-enhanced MRI features of the early -phase enhancement rate, enhancement amplitude, and signal-intensity (SI) time course are associated with the microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression of malignant and benign breast lesions. METHODS Sixty patients with breast lesions, detected with physical examination or conventional mammography, were examined pre-operatively with dynamic contrast-enhanced MRI from December 1998 to June 2000. Of these 60 patients, histopathological correlation was available in 38. These 38 patients(aged 29-73 years) formed the basis of this study. SI changes during dynamic scanning were assessed quantitatively. Early-phase enhancement rate and enhancement amplitude were calculated. Time-Sl curves of the lesions were obtained and classified according to their shapes as type I (which was steady enhancement to the end of the dynamic data acquisition at 7.5rain.), type Ⅱ (plateau of SI after avid initial contrast enhancement), or type Ⅲ (washout of SI after avid initial contrast enhancement). The mean MVD and VEGF expression of the lesions were measured with immunohistochemical staining methods in all the pathologic specimens by a pathologist without knowledge of the results of the MR examination. Care was taken to ensure identical location in the plane of the MR image and pathologic specimens. The relationships among dynamic contrast-enhanced MRI features, MVD, and VEGF expression of benign and malignant breast lesions were analyzed. RESULTS Histology revealed 21 malignancies and 17 benign lesions. The mean MVD and VEGF expression for the 21 malignant lesions were significantly higher than the mean MVD and VEGF expression for the 17 benign lesions (P60%) MR early-phase enhancement rate and time-SI curve type Ⅱ or Ⅲ showed a significant association with MVD and VEGF expression. All the differences mentioned above showed statistical significance (P 0

  2. Multi-modal Imaging of Angiogenesis in a Nude Rat Model of Breast Cancer Bone Metastasis Using Magnetic Resonance Imaging, Volumetric Computed Tomography and Ultrasound

    OpenAIRE

    Bäuerle, Tobias; Komljenovic, Dorde; Martin R. Berger; Semmler, Wolfhard

    2012-01-01

    Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell proliferation in the bone marrow cavity as well as for interaction of tumor and bone cells resulting in local bone destruction. Our aim was to develop a model of experimental bone metastasis that allows in vivo assessment of angiogenesis in skeletal lesions using non-invasive imaging techniques.

  3. Synthesis of Specific Nanoparticles for Targeting and Imaging Tumor Angiogenesis Using Electron-Beam Irradiation

    International Nuclear Information System (INIS)

    We have succeeded to synthesize PVDF nanoparticles by nanoemulsion polymerization and their functionalization with a peptide that presents an anti-angiogenic activity. Resulted nanoparticles present a radius of 60 nm. From FESEM images and light scattering measurements, we deduced that they were spherical and monodisperse. The alkyl radicals induced from electron beam irradiation combine immediately with the oxygen to form peroxide radicals. Because of a high specific area and small crystallite size, the radical decay with time is evidenced from EPR measurements. Despite this radical decay, electron beam irradiation allows us to graft PAA by radical polymerization onto freshly irradiated PVDF nanoparticles and then to immobilize CBO-P11 by click chemistry via a spacer arm. Evidences of grafting were shown using HRMAS NMR and MALDI-TOF mass spectrometry. Nanoparticles functionalized with an angiogenesis-targeting agent are an attractive option for anti-tumor therapy

  4. Positron emission tomography imaging of CD105 expression during tumor angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Hao [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Yang, Yunan [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Third Military Medical University, Department of Ultrasound, Xinqiao Hospital, Chongqing (China); Zhang, Yin; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Leigh, Bryan R. [TRACON Pharmaceuticals, Inc., San Diego, CA (United States); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States); University of Wisconsin - Madison, Departments of Radiology and Medical Physics, School of Medicine and Public Health, Madison, WI (United States)

    2011-07-15

    Overexpression of CD105 (endoglin) correlates with poor prognosis in many solid tumor types. Tumor microvessel density (MVD) assessed by CD105 staining is the current gold standard for evaluating tumor angiogenesis in the clinic. The goal of this study was to develop a positron emission tomography (PET) tracer for imaging CD105 expression. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and labeled with {sup 64}Cu. FACS analysis and microscopy studies were performed to compare the CD105 binding affinity of TRC105 and DOTA-TRC105. PET imaging, biodistribution, blocking, and ex vivo histology studies were performed on 4T1 murine breast tumor-bearing mice to evaluate the ability of {sup 64}Cu-DOTA-TRC105 to target tumor angiogenesis. Another chimeric antibody, cetuximab, was used as an isotype-matched control. FACS analysis of human umbilical vein endothelial cells (HUVECs) revealed no difference in CD105 binding affinity between TRC105 and DOTA-TRC105, which was further validated by fluorescence microscopy. {sup 64}Cu labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the 4T1 tumor uptake of the tracer was 8.0 {+-} 0.5, 10.4 {+-} 2.8, and 9.7 {+-} 1.8%ID/g at 4, 24, and 48 h post-injection, respectively (n = 3), higher than most organs at late time points which provided excellent tumor contrast. Biodistribution data as measured by gamma counting were consistent with the PET findings. Blocking experiments, control studies with {sup 64}Cu-DOTA-cetuximab, as well as ex vivo histology all confirmed the in vivo target specificity of {sup 64}Cu-DOTA-TRC105. This is the first successful PET imaging study of CD105 expression. Fast, prominent, persistent, and CD105-specific uptake of the tracer in the 4T1 tumor was observed. Further studies are warranted and currently underway. (orig.)

  5. A clinical study of contrast-enhanced digital mammography to correlate image descriptors with angiogenesis

    International Nuclear Information System (INIS)

    Contrast-enhanced digital mammography (CEDM) is a technique based on the subtraction of images applying a contrast medium (CM), with the goal of eliminating the breast anatomical structure in the images. The CM generally contains iodine, due to the relatively high attenuation of X rays in iodine with respect to breast tissues. It is assumed that CEDM images enhance the visualization of the CM next to rapidly growing lesions as a consequence of angiogenesis, the formation of new microvessels. This study is designed to investigate the possible correlation between iodine uptake in CEDM images and microvessel density in breast lesions. 19 patients, whose mammographies were classified as BIRADS 4-5, were included. A series of 6 images was acquired under one single breast compression, combining dual-energy and temporal acquisition. Low- and high-energy masks were acquired, CM was injected before the CM temporal sequence, a biopsy was obtained after the images, specific biomarkers for blood and lymphatic neo-microvessels were applied, and microvessel density was evaluated. In the processing, masks were subtracted from weighted CM images and the weight factor was a matrix obtained from the masks and contained pixel-by-pixel anatomical and radiological information. Iodine uptake after the subtraction was quantified by contrast between the lesion and normal glandular tissue. Contrast was transformed into iodine mass thickness using calibrated samples. 11 lesions were malignant and 8, benign. The subtraction formalism severely reduced the anatomic noise in resulting images, compared with alternative techniques based on mean pixel values within regions-of-interest. Five types of time-intensity curves were identified, qualitatively similar to what is known for magnetic resonance images (MRI). Blood and lymphatic microvessel densities were correlated (r=0.94 p<0.05) and mean blood values in cancer were twice those in benign cases. No correlation was found between image contrast

  6. Biological evaluation of an ornithine-modified 99mTc-labeled RGD peptide as an angiogenesis imaging agent

    International Nuclear Information System (INIS)

    Introduction: Radiolabeled RGD peptides that specifically target integrin ανβ3 have great potential in early tumor detection through noninvasive monitoring of tumor angiogenesis. Based on previous findings of our group on radiopeptides containing positively charged aminoacids, we developed a new cyclic cRGDfK derivative, c(RGDfK)-(Orn)3-CGG. This new peptide availing the polar linker (Orn)3 and the 99mTc-chelating moiety CGG (Cys-Gly-Gly) is appropriately designed for 99mTc-labeling, as well as consequent conjugation onto nanoparticles. Methods: A tumor imaging agent, c(RGDfK)-(Orn)3-[CGG-99mTc], is evaluated with regard to its radiochemical, radiobiological and imaging characteristics. Results: The complex c(RGDfK)-(Orn)3-[CGG-99mTc] was obtained in high radiochemical yield (> 98%) and was stable in vitro and ex vivo. It presented identical to the respective, fully analytically characterized 185/187Re complex retention time in RP-HPLC. In contrary to other RGD derivatives, we showed that the new radiopeptide exhibits kidney uptake and urine excretion due to the ornithine linker. High tumor uptake (3.87 ± 0.48% ID/g at 60 min p.i.) was observed and was maintained relatively high even at 24 h p.i. (1.83 ± 0.05 % ID/g), thus providing well-defined scintigraphic imaging. Accumulation in other organs was negligible. Blocking experiments indicated target specificity for integrin receptors in U87MG glioblastoma cells. Conclusion: Due to its relatively high tumor uptake, renal elimination and negligible abdominal localization, the new 99mTc-RGD peptide is considered promising in the field of imaging ανβ3-positive tumors. However, the preparation of multifunctional SPECT/MRI contrast agents (RGD-conjugated nanoparticles) for dual modality imaging of integrin expressing tumors should be further investigated

  7. An imaging-based computational model for simulating angiogenesis and tumour oxygenation dynamics.

    Science.gov (United States)

    Adhikarla, Vikram; Jeraj, Robert

    2016-05-21

    Tumour growth, angiogenesis and oxygenation vary substantially among tumours and significantly impact their treatment outcome. Imaging provides a unique means of investigating these tumour-specific characteristics. Here we propose a computational model to simulate tumour-specific oxygenation changes based on the molecular imaging data. Tumour oxygenation in the model is reflected by the perfused vessel density. Tumour growth depends on its doubling time (T d) and the imaged proliferation. Perfused vessel density recruitment rate depends on the perfused vessel density around the tumour (sMVDtissue) and the maximum VEGF concentration for complete vessel dysfunctionality (VEGFmax). The model parameters were benchmarked to reproduce the dynamics of tumour oxygenation over its entire lifecycle, which is the most challenging test. Tumour oxygenation dynamics were quantified using the peak pO2 (pO2peak) and the time to peak pO2 (t peak). Sensitivity of tumour oxygenation to model parameters was assessed by changing each parameter by 20%. t peak was found to be more sensitive to tumour cell line related doubling time (~30%) as compared to tissue vasculature density (~10%). On the other hand, pO2peak was found to be similarly influenced by the above tumour- and vasculature-associated parameters (~30-40%). Interestingly, both pO2peak and t peak were only marginally affected by VEGFmax (~5%). The development of a poorly oxygenated (hypoxic) core with tumour growth increased VEGF accumulation, thus disrupting the vessel perfusion as well as further increasing hypoxia with time. The model with its benchmarked parameters, is applied to hypoxia imaging data obtained using a [(64)Cu]Cu-ATSM PET scan of a mouse tumour and the temporal development of the vasculature and hypoxia maps are shown. The work underscores the importance of using tumour-specific input for analysing tumour evolution. An extended model incorporating therapeutic effects can serve as a powerful tool for

  8. An imaging-based computational model for simulating angiogenesis and tumour oxygenation dynamics

    Science.gov (United States)

    Adhikarla, Vikram; Jeraj, Robert

    2016-05-01

    Tumour growth, angiogenesis and oxygenation vary substantially among tumours and significantly impact their treatment outcome. Imaging provides a unique means of investigating these tumour-specific characteristics. Here we propose a computational model to simulate tumour-specific oxygenation changes based on the molecular imaging data. Tumour oxygenation in the model is reflected by the perfused vessel density. Tumour growth depends on its doubling time (T d) and the imaged proliferation. Perfused vessel density recruitment rate depends on the perfused vessel density around the tumour (sMVDtissue) and the maximum VEGF concentration for complete vessel dysfunctionality (VEGFmax). The model parameters were benchmarked to reproduce the dynamics of tumour oxygenation over its entire lifecycle, which is the most challenging test. Tumour oxygenation dynamics were quantified using the peak pO2 (pO2peak) and the time to peak pO2 (t peak). Sensitivity of tumour oxygenation to model parameters was assessed by changing each parameter by 20%. t peak was found to be more sensitive to tumour cell line related doubling time (~30%) as compared to tissue vasculature density (~10%). On the other hand, pO2peak was found to be similarly influenced by the above tumour- and vasculature-associated parameters (~30–40%). Interestingly, both pO2peak and t peak were only marginally affected by VEGFmax (~5%). The development of a poorly oxygenated (hypoxic) core with tumour growth increased VEGF accumulation, thus disrupting the vessel perfusion as well as further increasing hypoxia with time. The model with its benchmarked parameters, is applied to hypoxia imaging data obtained using a [64Cu]Cu-ATSM PET scan of a mouse tumour and the temporal development of the vasculature and hypoxia maps are shown. The work underscores the importance of using tumour-specific input for analysing tumour evolution. An extended model incorporating therapeutic effects can serve as a powerful tool for

  9. Positron emission tomography imaging of tumor angiogenesis with a 66Ga-labeled monoclonal antibody.

    Science.gov (United States)

    Engle, Jonathan W; Hong, Hao; Zhang, Yin; Valdovinos, Hector F; Myklejord, Duane V; Barnhart, Todd E; Theuer, Charles P; Nickles, Robert J; Cai, Weibo

    2012-05-01

    The goal of this study was to develop a (66)Ga-based positron emission tomography (PET) tracer for noninvasive imaging of CD105 expression during tumor angiogenesis, a hallmark of cancer. (66)Ga was produced using a cyclotron with (nat)Zn or isotopically enriched (66)Zn targets. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-Bn-NOTA) and labeled with (66)Ga. No difference in CD105 binding affinity or specificity was observed between TRC105 and NOTA-TRC105 based on flow cytometry analysis. Reactivity of (66)Ga for NOTA, corrected to the end of bombardment, was between 74 and 222 GBq/μmol for both target enrichments with 80% radiochemical yield. Serial PET imaging revealed that the murine breast cancer 4T1 tumor uptake of (66)Ga-NOTA-TRC105 was 5.9 ± 1.6, 8.5 ± 0.6, and 9.0 ± 0.6% ID/g at 4, 20, and 36 h postinjection, respectively (n = 4). At the last time point, tumor uptake was higher than that of all organs, which gave excellent tumor contrast with a tumor/muscle ratio of 10.1 ± 1.1. Biodistribution data as measured by gamma counting were consistent with the PET findings. Blocking experiment, control studies with (66)Ga-NOTA-cetuximab, as well as ex vivo histology all confirmed the in vivo target specificity of (66)Ga-NOTA-TRC105. Successful PET imaging with high specific activity (66)Ga (>700 GBq/μmol has been achieved) as the radiolabel opens many new possibilities for future PET research with antibodies or other targeting ligands. PMID:22519890

  10. Tumor angiogenesis imaging: radioiodinated NGR peptide containing t-butyloxycarbonyl as a pharmacokinetic modifier

    International Nuclear Information System (INIS)

    Tumor growth and metastasis largely depend on persistent new blood vessel growth, which is even the rate-limiting step in solid tumor growth. Identified as a cell adhesion motif, NGR has been proven an effective tumor-homing agent, binding specifically on CD13/APN that is expressed in tumor vasculature undergoing angiogenesis and not detected in blood vessels of various other normal tissues. Whether NGR also possesses the potential of tumor imaging in vivo is still in suspension. Internalization of small peptides is an important phenomenon. Internalization brings on deiodination of directly radioiodinated small peptides, and the low weight radiolabeled catabolites are quickly removed from tumor, resulting in poor tumor imaging. It is of good value to study whether Boc could be an effective tyrosine-protecting group, increasing peptide's resistance to deiodination, meanwhile preserving peptide's original specialty. The cyclic peptide YGGGGGCNGRC (G5) and the t-butyloxycarbonyl (Boc)-modified analog (Boc-G5) were synthesized and radiolabeled with iodine-131. Biodistribution results in normal mice indicated that in the case of G5, deiodination in vivo was found, whereas for Boc-G5, the phenomenon was scarce (Figs.1 and 2). Although the radiotracer clearance in tumor became faster for Boc-G5, tumor-to-tissue ratios still improved, arid at 1 h post injection, the uptake ratios of tumor to muscle, blood, heart, and lung reached 4.73, 1.70, 4.09 and 1.70, respectively. It is demonstrated that Boc-group is an effective prosthetic one to prevent deiodination in vivo and meliorate tumor imaging for small peptide.

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

    International Nuclear Information System (INIS)

    , PS of inflammatory nodule were significantly lower than that of peripheral lung cancer (all P < 0.05). PH, PHpm/PHa, BF, and BV of benign nodule were significantly lower than those of inflammatory nodule (all P < 0.05), rather than PS and MTT (mean transit time) (all P > 0.05). PH, PHpm/PHa, BV, and PS of benign nodule were significantly lower than those of peripheral lung cancer (all P < 0.05). In the case of VEGF positive expression, MVD was positively correlated with PH, PHpm/PHa, BF, BV, and PS of peripheral lung cancer and PS of benign nodule (all P < 0.05). Multi-slice spiral CT perfusion imaging closely correlated with tumor angiogenesis and reflected MVD measurement and VEGF expression. It provided not only a non-invasive method of quantitative assessment for blood flow patterns of peripheral pulmonary nodules but also an applicable diagnostic method for peripheral pulmonary nodules

  12. PET imaging of angiogenesis after myocardial infarction/reperfusion using a one-step labeled integrin-targeted tracer {sup 18}F-AlF-NOTA-PRGD2

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Haokao [The Fourth Military Medical University, Department of Cardiology, Xijing Hospital, Xi' an (China); National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Laboratory of Molecular Imaging and Nanomedicine (LOMIN), Bethesda, MD (United States); Lang, Lixin; Guo, Ning; Quan, Qimeng; Hu, Shuo; Kiesewetter, Dale O.; Niu, Gang; Chen, Xiaoyuan [National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Laboratory of Molecular Imaging and Nanomedicine (LOMIN), Bethesda, MD (United States); Cao, Feng [The Fourth Military Medical University, Department of Cardiology, Xijing Hospital, Xi' an (China)

    2012-04-15

    }{sub 3} expression as measured by CD31 and CD61 immunostaining analysis. PET imaging using one-step labeled {sup 18}F-AlF-NOTA-PRGD2 allows noninvasive visualization of ischemia/reperfusion-induced myocardial angiogenesis longitudinally. The favorable in vivo kinetics and easy production method of this integrin-targeted PET tracer facilitates its future clinical translation for lesion evaluation and therapy response monitoring in patients with occlusive cardiovascular diseases. (orig.)

  13. Positron emission tomography imaging of angiogenesis in a murine hindlimb ischemia model with 64Cu-labeled TRC105.

    Science.gov (United States)

    Orbay, Hakan; Zhang, Yin; Hong, Hao; Hacker, Timothy A; Valdovinos, Hector F; Zagzebski, James A; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2013-07-01

    The goal of this study was to assess ischemia-induced angiogenesis with (64)Cu-NOTA-TRC105 positron emission tomography (PET) in a murine hindlimb ischemia model of peripheral artery disease (PAD). CD105 binding affinity/specificity of NOTA-conjugated TRC105 (an anti-CD105 antibody) was evaluated by flow cytometry, which exhibited no difference from unconjugated TRC105. BALB/c mice were anesthetized, and the right femoral artery was ligated to induce hindlimb ischemia, with the left hindlimb serving as an internal control. Laser Doppler imaging showed that perfusion in the ischemic hindlimb plummeted to ∼ 20% of the normal level after surgery and gradually recovered to near normal level on day 24. Ischemia-induced angiogenesis was noninvasively monitored and quantified with (64)Cu-NOTA-TRC105 PET on postoperative days 1, 3, 10, 17, and 24. (64)Cu-NOTA-TRC105 uptake in the ischemic hindlimb increased significantly from the control level of 1.6 ± 0.2 %ID/g to 14.1 ± 1.9 %ID/g at day 3 (n = 3) and gradually decreased with time (3.4 ± 1.9 %ID/g at day 24), which correlated well with biodistribution studies performed on days 3 and 24. Blocking studies confirmed the CD105 specificity of tracer uptake in the ischemic hindlimb. Increased CD105 expression on days 3 and 10 following ischemia was confirmed by histology and reverse transcription polymerase chain reaction (RT-PCR). This is the first report of PET imaging of CD105 expression during ischemia-induced angiogenesis. (64)Cu-NOTA-TRC105 PET may play multiple roles in future PAD-related research and improve PAD patient management by identifying the optimal timing of treatment and monitoring the efficacy of therapy. PMID:23738915

  14. 19F molecular MR imaging for detection of brain tumor angiogenesis: in vivo validation using targeted PFOB nanoparticles

    International Nuclear Information System (INIS)

    Molecular imaging with magnetic resonance imaging (MRI) targeted contrast agents has emerged as a promising diagnostic approach in cancer research to detect associated bio-markers. In this work, the potential of 19F MRI was investigated to detect angiogenesis with αvβ3-targeted perfluoro-octylbromide nanoparticles (PFOB NP) in a U87 glioblastoma mouse model at 7 Tesla. Mice were injected intravenously with targeted or non-targeted NP and 19F images were immediately acquired for 90 min using a PFOB-dedicated MRI sequence. Mice infused with targeted NP exhibited higher concentrations in tumors than mice of the control group, despite the presence of nonspecific signal originating from the blood. Imaging results were corroborated by histology and fluorescence imaging, suggesting specific binding of targeted NP to αvβ3 integrin. Two other groups of mice were injected 24 h before imaging to allow blood clearance but no significant differences were found between both groups, probably due to a loss of specificity of PFOB NP. This is the first demonstration of the ability of 19F MRI to detect αvβ3 -integrin endothelial expression in brain tumors in vivo. (authors)

  15. In Vivo Magnetic Resonance and Fluorescence Dual-Modality Imaging of Tumor Angiogenesis in Rats Using GEBP11 Peptide Targeted Magnetic Nanoparticles.

    Science.gov (United States)

    Su, Tao; Wang, Yabin; Wang, Jiinda; Han, Dong; Ma, Sai; Cao, Jianbo; Li, Xiujuan; Zhang, Ran; Qiao, Hongyu; Liang, Jimin; Liu, Gang; Yang, Bo; Liang, Shuhui; Nie, Yongzhan; Wu, Kaichun; Li, Jiayi; Cao, Feng

    2016-05-01

    Angiogenesis is an essential process for tumor progression. Tumor vasculature-targeting peptides have shown great potential for use in cancer imaging and therapy. Our previous studies have shown that GEBP11, a novel vasculature-specific binding peptide that exhibits high affinity and specificity to tumor angiogenesis, is a promising candidate for the diagnosis and targeted radiotherapy of gastric cancer. In the present study, we developed a novel magnetic resonance and fluorescence (MR/Fluo) dual-modality imaging probe by covalently coupling 2,3-dimercaptosuccinnic acid-coated paramagnetic nanoparticles (DMSA-MNPs) and Cy5.5 to the GEBP11 peptide. The probe Cy5.5-GEBP11-DMSA-MNPs (CGD-MNPs), with a hydrodynamic diameter of 82.8 ± 6.5 nm, exhibited good imaging properties, high stability and little cytotoxicity. In vivo MR/Fluo imaging revealed that CGD-MNPs were successfully applied to visualize tumor angiogenesis in SGC-7901 xenograft mouse models. Prussian blue and CD31 immunohistochemical staining confirmed that CGD-MNPs co-localized with tumor blood vessels. In conclusion, CGD-MNPs are promising candidates for use as MR and fluorescence imaging probes for visualizing gastric cancer angiogenesis in vivo. PMID:27305822

  16. Multi-modal imaging of angiogenesis in a nude rat model of breast cancer bone metastasis using magnetic resonance imaging, volumetric computed tomography and ultrasound.

    Science.gov (United States)

    Bäuerle, Tobias; Komljenovic, Dorde; Berger, Martin R; Semmler, Wolfhard

    2012-01-01

    Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell proliferation in the bone marrow cavity as well as for interaction of tumor and bone cells resulting in local bone destruction. Our aim was to develop a model of experimental bone metastasis that allows in vivo assessment of angiogenesis in skeletal lesions using non-invasive imaging techniques. For this purpose, we injected 10(5) MDA-MB-231 human breast cancer cells into the superficial epigastric artery, which precludes the growth of metastases in body areas other than the respective hind leg. Following 25-30 days after tumor cell inoculation, site-specific bone metastases develop, restricted to the distal femur, proximal tibia and proximal fibula. Morphological and functional aspects of angiogenesis can be investigated longitudinally in bone metastases using magnetic resonance imaging (MRI), volumetric computed tomography (VCT) and ultrasound (US). MRI displays morphologic information on the soft tissue part of bone metastases that is initially confined to the bone marrow cavity and subsequently exceeds cortical bone while progressing. Using dynamic contrast-enhanced MRI (DCE-MRI) functional data including regional blood volume, perfusion and vessel permeability can be obtained and quantified. Bone destruction is captured in high resolution using morphological VCT imaging. Complementary to MRI findings, osteolytic lesions can be located adjacent to sites of intramedullary tumor growth. After contrast agent application, VCT angiography reveals the macrovessel architecture in bone metastases in high resolution, and DCE-VCT enables insight in the microcirculation of these lesions. US is applicable to assess morphological and functional features from skeletal lesions due to local osteolysis of cortical bone. Using B-mode and Doppler techniques, structure and perfusion of the soft tissue metastases can be evaluated

  17. MULTIVARIATE MATHEMATICAL MORPHOLOGY FOR DCE-MRI IMAGE ANALYSIS IN ANGIOGENESIS STUDIES

    Directory of Open Access Journals (Sweden)

    Guillaume Noyel

    2014-05-01

    Full Text Available We propose a new computer aided detection framework for tumours acquired on DCE-MRI (Dynamic Contrast Enhanced Magnetic Resonance Imaging series on small animals. To perform this approach, we consider DCE-MRI series as multivariate images. A full multivariate segmentation method based on dimensionality reduction, noise filtering, supervised classification and stochastic watershed is explained and tested on several data sets. The two main key-points introduced in this paper are noise reduction preserving contours and spatio temporal segmentation by stochastic watershed. Noise reduction is performed in a special way to select factorial axes of Factor Correspondence Analysis in order to preserves contours. Then a spatio-temporal approach based on stochastic watershed is used to segment tumours. The results obtained are in accordance with the diagnosis of the medical doctors.

  18. Development of a New Positron Emission Tomography Tracer for Targeting Tumor Angiogenesis: Synthesis, Small Animal Imaging, and Radiation Dosimetry

    Directory of Open Access Journals (Sweden)

    David S. Lalush

    2013-05-01

    Full Text Available Angiogenesis plays a key role in cancer progression and correlates with disease aggressiveness and poor clinical outcomes. Affinity ligands discovered by screening phage display random peptide libraries can be engineered to molecularly target tumor blood vessels for noninvasive imaging and early detection of tumor aggressiveness. In this study, we tested the ability of a phage-display-selected peptide sequence recognizing specifically bone marrow- derived pro-angiogenic tumor-homing cells, the QFP-peptide, radiolabeled with 64Cu radioisotope to selectively image tumor vasculature in vivo by positron emission tomography (PET. To prepare the targeted PET tracer we modified QFP-phage with the DOTA chelator and radiolabeled the purified QFP-phage-DOTA intermediate with 64Cu to obtain QFP-targeted radioconjugate with high radiopharmaceutical yield and specific activity. We evaluated the new PET tracer in vivo in a subcutaneous (s.c. Lewis lung carcinoma (LLC mouse model and conducted tissue distribution, small animal PET/CT imaging study, autoradiography, histology, fluorescence imaging, and dosimetry assessments. The results from this study show that, in the context of the s.c. LLC immunocompetent mouse model, the QFP-tracer can target tumor blood vessels selectively. However, further optimization of the biodistribution and dosimetry profile of the tracer is necessary to ensure efficient radiopharmaceutical applications enabled by the biological specificity of the QFP-peptide.

  19. Neo-angiogenesis metabolic biomarker of tumor-genesis tracking by infrared joystick contact imaging in personalized homecare system

    Science.gov (United States)

    Szu, Harold; Hoekstra, Philip; Landa, Joseph; Vydelingum, Nadarajen A.

    2014-05-01

    We describe an affordable, harmless, and administrative (AHA) metabolic biomarker (MBM) for homecare cancer screening. It may save hundreds of thousands of women's and thousands of men's lives every year from breast cancer and melanoma. The goal is to increase the specificity of infrared (IR) imagery to reduce the false alarm rate (FAR). The patient's hands are immersed in icy cold water, about 11oC, for 30 seconds. We then compare two IR images, taken before and after the cold stimulus, and the difference reveals an enhanced signal and noise ratio (SNR) at tumorigenesis sites since the contraction of capillaries under cold challenge is natural to healthy capillaries, except those newly built capillaries during angiogenesis (Folkman, Nature 1995). Concomitant with the genome and the phenome (molecular signaling by phosphor-mediate protein causing inflammation by platelet activating factor (PAF) that transform cells from benign to malignant is the amplification of nitric oxide (NO) syntheses, a short-lived reactive oxygen species (ROS) that dilates regional blood vessels; superseding normal autonomic nervous system regulation. A rapidly growing tumor site might implicate accumulation of ROS, for which NO can rapidly stretch the capillary bed system usually having thinning muscular lining known as Neo-Angiogenesis (NA) that could behave like Leaky In-situ Faucet Effect (LIFE) in response to cold challenge. To emphasize the state of art knowledge of NA, we mentioned in passing the first generation of an anticapillary growth drug, Avastin by Genetech; it is an antibody protein that is injected for metastasis, while the second generation drug; Sorafenib by Bayers (2001) and Sutent by Pfizer (2000) both target molecular signaling loci to block receptor associated tyrosine kinase induced protein phosphorylation in order to reverse the angiogenesis. Differentiating benign from malignant in a straightforward manner is required to achieve the wellness protocol, yet would

  20. Pravastatin stimulates angiogenesis in a murine hindlimb ischemia model: a positron emission tomography imaging study with 64Cu-NOTA-TRC105

    Science.gov (United States)

    Orbay, Hakan; Hong, Hao; Koch, Jill M; Valdovinos, Hector F; Hacker, Timothy A; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2014-01-01

    In this study, 64Cu-NOTA-TRC105 (TRC105 is an anti-CD105 monoclonal antibody that binds to both human and murine CD105) positron emission tomography (PET) was used to assess the response to pravastatin treatment in a murine model of peripheral artery disease (PAD). Hindlimb ischemia was induced by ligation of the right femoral arteries in BALB/c mice under anesthesia, and the left hindlimb served as an internal control. Mice in the treatment group were given intraperitoneal pravastatin daily until the end of the study, whereas the animals in the control group were injected with 0.9% sodium chloride solution. Laser Doppler imaging showed that blood flow in the ischemic hindlimb plummeted to ~20% of the normal level after surgery, and gradually recovered to near normal level on day 10 in the treatment group and on day 20 in the control group. Angiogenesis was non-invasively monitored and quantified with 64Cu-NOTA-TRC105 PET on postoperative days 3, 10, 17, and 24. Tracer uptake at 48 h post-injection in the ischemic hindlimb in the treatment group was significantly higher than that of the control group on day 10 (20.5 ± 1.9 %ID/g vs 11.4 ± 1.5 %ID/g), suggesting increased CD105 expression and higher level of angiogenesis upon pravastatin treatment, and gradually decreased to background levels in both groups (4.9 ± 0.8 %ID/g vs 3.4 ± 1.9 %ID/g on day 24). The in vivo PET data correlated well with ex vivo biodistribution studies performed on day 24. Increased CD105 expression on days 3 and 10 following ischemia was further confirmed by immunofluorescence staining. Taken together, our results indicated that 64Cu-NOTA-TRC105 PET is a suitable and non-invasive method to monitor the angiogenesis and therapeutic response in PAD, which can also be utilized for non-invasive evaluation of other pro-angiogenic/anti-angiogenic drugs in other cardiovascular diseases and cancer. PMID:24349621

  1. Pravastatin stimulates angiogenesis in a murine hindlimb ischemia model: a positron emission tomography imaging study with (64)Cu-NOTA-TRC105.

    Science.gov (United States)

    Orbay, Hakan; Hong, Hao; Koch, Jill M; Valdovinos, Hector F; Hacker, Timothy A; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2013-01-01

    In this study, (64)Cu-NOTA-TRC105 (TRC105 is an anti-CD105 monoclonal antibody that binds to both human and murine CD105) positron emission tomography (PET) was used to assess the response to pravastatin treatment in a murine model of peripheral artery disease (PAD). Hindlimb ischemia was induced by ligation of the right femoral arteries in BALB/c mice under anesthesia, and the left hindlimb served as an internal control. Mice in the treatment group were given intraperitoneal pravastatin daily until the end of the study, whereas the animals in the control group were injected with 0.9% sodium chloride solution. Laser Doppler imaging showed that blood flow in the ischemic hindlimb plummeted to ~20% of the normal level after surgery, and gradually recovered to near normal level on day 10 in the treatment group and on day 20 in the control group. Angiogenesis was non-invasively monitored and quantified with (64)Cu-NOTA-TRC105 PET on postoperative days 3, 10, 17, and 24. Tracer uptake at 48 h post-injection in the ischemic hindlimb in the treatment group was significantly higher than that of the control group on day 10 (20.5 ± 1.9 %ID/g vs 11.4 ± 1.5 %ID/g), suggesting increased CD105 expression and higher level of angiogenesis upon pravastatin treatment, and gradually decreased to background levels in both groups (4.9 ± 0.8 %ID/g vs 3.4 ± 1.9 %ID/g on day 24). The in vivo PET data correlated well with ex vivo biodistribution studies performed on day 24. Increased CD105 expression on days 3 and 10 following ischemia was further confirmed by immunofluorescence staining. Taken together, our results indicated that (64)Cu-NOTA-TRC105 PET is a suitable and non-invasive method to monitor the angiogenesis and therapeutic response in PAD, which can also be utilized for non-invasive evaluation of other pro-angiogenic/anti-angiogenic drugs in other cardiovascular diseases and cancer. PMID:24349621

  2. WE-E-17A-01: Characterization of An Imaging-Based Model of Tumor Angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Adhikarla, V; Jeraj, R [Medical College of Wisconsin, Milwaukee, WI (United States)

    2014-06-15

    Purpose: Understanding the transient dynamics of tumor oxygenation is important when evaluating tumor-vasculature response to anti-angiogenic therapies. An imaging-based tumor-vasculature model was used to elucidate factors that affect these dynamics. Methods: Tumor growth depends on its doubling time (Td). Hypoxia increases pro-angiogenic factor (VEGF) concentration which is modeled to reduce vessel perfusion, attributing to its effect of increasing vascular permeability. Perfused vessel recruitment depends on the existing perfused vasculature, VEGF concentration and maximum VEGF concentration (VEGFmax) for vessel dysfunction. A convolution-based algorithm couples the tumor to the normal tissue vessel density (VD-nt). The parameters are benchmarked to published pre-clinical data and a sensitivity study evaluating the changes in the peak and time to peak tumor oxygenation characterizes them. The model is used to simulate changes in hypoxia and proliferation PET imaging data obtained using [Cu- 61]Cu-ATSM and [F-18]FLT respectively. Results: Td and VD-nt were found to be the most influential on peak tumor pO2 while VEGFmax was marginally influential. A +20 % change in Td, VD-nt and VEGFmax resulted in +50%, +25% and +5% increase in peak pO2. In contrast, Td was the most influential on the time to peak oxygenation with VD-nt and VEGFmax playing marginal roles. A +20% change in Td, VD-nt and VEGFmax increased the time to peak pO2 by +50%, +5% and +0%. A −20% change in the above parameters resulted in comparable decreases in the peak and time to peak pO2. Model application to the PET data was able to demonstrate the voxel-specific changes in hypoxia of the imaged tumor. Conclusion: Tumor-specific doubling time and vessel density are important parameters to be considered when evaluating hypoxia transients. While the current model simulates the oxygen dynamics of an untreated tumor, incorporation of therapeutic effects can make the model a potent tool for analyzing

  3. Evaluation of Tumor Angiogenesis by MRI Study Using Iron Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mansour Ashoor

    2010-05-01

    Full Text Available Angiogenesis is the growth of new blood vessels from existing ones and it is a perquisite for the growth, invasion and metastasis of solid tumors. This complex process involves multiple steps and pathways dependent on the local balance between positive and negative regulatory factors, as well as interactions among the tumor, its vasculature and the surrounding extracellular tissue matrix. Tumors lay dormant yet viable, unable to grow beyond 2-3 mm3 in size without angiogenesis."nWith the development of novel therapies for treat-ment of several diseases, directed noninvasive imaging strategies will be critical for defining the pathophysiology of angiogenesis. Imaging modalities used to detect angiogenesis include PET, SPECT, MRI, CT, US and near-infrared optical imaging. For these modalities, methods have been developed to measure blood volume, blood flow and several other semi quantitative and quantitative kinetic hemodynamic parameters such as vascular permeability. Characteristic molecular makers of angiogenesis may be visualized with the aid of molecular imaging agents such as VEGFs or the α vß3 integrin. "nMRI is a practical modality for assessing angiogenesis over time because it is already widely used clinically to assess tumor growth and for response evaluation. Anatomical information can be co registered with functional and molecular information within a single imaging method. Moreover, MRI does not involve ionizing radiation and the commonly used contrast agent has low toxicity. "nSuper paramagnetic iron oxides (SPIO are FDA-approved contrast agents for use in magnetic reson-ance (MR imaging. Most of the administered SPIO end up in the reticuloendotelial system via endocytosis and the iron core released from the SPIO is utilized in normal iron metabolism pathways. We utilize the paramagnetic characteristics of SPIO to improve the contrast of the image in MRI."nFor the first time we will introduce a method for evaluating angiogenesis

  4. Visualization of Tumor Angiogenesis Using MR Imaging Contrast Agent Gd-DTPA-anti-VEGF Receptor 2 Antibody Conjugate in a Mouse Tumor Model

    International Nuclear Information System (INIS)

    To visualize tumor angiogenesis using the MRI contrast agent, Gd- DTPA-anti-VEGF receptor 2 antibody conjugate, with a 4.7-Tesla MRI instrument in a mouse model. We designed a tumor angiogenesis-targeting T1 contrast agent that was prepared by the bioconjugation of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and an anti-vascular endothelial growth factor receptor-2 (VEGFR2) antibody. The specific binding of the agent complex to cells that express VEGFR2 was examined in cultured murine endothelial cells (MS-1 cells) with a 4.7-Tesla magnetic resonance imaging scanner. Angiogenesis-specific T1 enhancement was imaged with the Gd-DTPA-anti-VEGFR2 antibody conjugate using a CT-26 adenocarcinoma tumor model in eight mice. As a control, the use of the Gd-DTPA-anti-rat immunoglobulin G (Gd-DTPA-anti-rat IgG) was imaged with a tumor model in eight mice. Statistical significance was assessed using the Mann-Whitney test. Tumor tissue was examined by immunohistochemical analysis. The Gd-DTPA-anti-VEGFR2 antibody conjugate showed predominant binding to cultured endothelial cells that expressed a high level of VEGFR2. Signal enhancement was approximately three-fold for in vivo T1-weighted MR imaging with the use of the Gd-DTPA-anti-VEGFR2 antibody conjugate as compared with the Gd-DTPA-rat IgG in the mouse tumor model (p < 0.05). VEGFR2 expression in CT-26 tumor vessels was demonstrated using immunohistochemical staining. MR imaging using the Gd-DTPA-anti-VEGFR2 antibody conjugate as a contrast agent is useful in visualizing noninvasively tumor angiogenesis in a murine tumor model

  5. Thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105: Synthesis, characterization and application in MR imaging of tumor angiogenesis

    International Nuclear Information System (INIS)

    Objective: To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI). Methods: Fe2O3/Au nanoparticles (hybrids) were prepared by reducing Au3+ on the surface of Fe2O3 nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo. Results: The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SIR) was positively correlated with the tumor MVD (R2 = 0.8972). Conclusion: Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe2O3/Au nanoparticles can efficiently target CD105 expressed by HUVECs. Furthermore, the hybrid-PEG-CD105 nanoparticles can be

  6. Relationship of binding specificity and structural property of the technetium-99m complexes for tumor hypoxia and tumor angiogenesis imaging

    International Nuclear Information System (INIS)

    The growth of tumor requires nutrition and oxygen. Tumor cells will become hypoxic when the supply of oxygen is insufficient. Hypoxic tumor cells will not only resist radiation therapy and chemotherapy, but also induce angiogenesis for oxygen supply and for metastasis. Therefore, detection of tumor hypoxia and tumor angiogenesis with high sensitive radio labeled imaging agents is important. Hypoxic tumor cells may display some molecules as tumor markers for the specific binding with radiopharmaceuticals. Radiopharmaceuticals, unlike the non-radioactive drugs, are trace compounds in a given dosage. Due to the extreme low concentration, the non-specific accumulation of the radiotracers by blood cells and proteins, tissues, and organs can be even more serious compared to the non-radioactive drugs. The non-specific accumulation of the radiotracers can make the ratios of tumor/tissue (in terms of i.d.%/g) falling to the range of 2∼7 [1-2]. Non-specific binding of radiopharmaceuticals is common, but detailed studies on it are poor documented. This presentation reports the study of the relationship of non-specific accumulation and the structural property of two type of 99mTC labeled compounds: (a) 99mTc-(amineoxime) containing either 2-nitroimidazole (2-NI, as hypoxia tumor cells specific agents), or 4-nitro- imidazole (4-NI, as control), or aniline (as reference) groups; (b) 99mTc-(arginine-glycine- aspartic acid, RGD, as tumor angiogenesis specific agents) and 99mTc-(arginine-glycine- glutarmic acid, RGE, as control). The 99mTc-(amine-oxime) complexes, in addition to the 2-NI, 4-NI, and aniline groups, contain methyl-, ethyl-, propyl-, iso-butyl-, t-butyl-, phenyl-, and Benzyl- groups as well to make the radiotracers differing in structure and in lipophilicity , while the lipophilicity of a radiotracer plays an important role in non-specific cellular accumulation and protein binding, The results demonstrated that (1) the complex containing 2-NI showed specific

  7. Imaging tumor angiogenesis in breast cancer experimental lung metastasis with positron emission tomography, near-infrared fluorescence, and bioluminescence.

    Science.gov (United States)

    Zhang, Yin; Hong, Hao; Nayak, Tapas R; Valdovinos, Hector F; Myklejord, Duane V; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2013-07-01

    The goal of this study was to develop a molecular imaging agent that can allow for both positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging of CD105 expression in metastatic breast cancer. TRC105, a chimeric anti-CD105 monoclonal antibody, was labeled with both a NIRF dye (i.e., IRDye 800CW) and (64)Cu to yield (64)Cu-NOTA-TRC105-800CW. Flow cytometry analysis revealed no difference in CD105 binding affinity/specificity between TRC105 and NOTA-TRC105-800CW. Serial bioluminescence imaging (BLI) was carried out to non-invasively monitor the lung tumor burden in BALB/c mice, after intravenous injection of firefly luciferase-transfected 4T1 (i.e., fLuc-4T1) murine breast cancer cells to establish the experimental lung metastasis model. Serial PET imaging revealed that fLuc-4T1 lung tumor uptake of (64)Cu-NOTA-TRC105-800CW was 11.9 ± 1.2, 13.9 ± 3.9, and 13.4 ± 2.1 %ID/g at 4, 24, and 48 h post-injection respectively (n = 3). Biodistribution studies, blocking fLuc-4T1 lung tumor uptake with excess TRC105, control experiments with (64)Cu-NOTA-cetuximab-800CW (which served as an isotype-matched control), ex vivo BLI/PET/NIRF imaging, autoradiography, and histology all confirmed CD105 specificity of (64)Cu-NOTA-TRC105-800CW. Successful PET/NIRF imaging of tumor angiogenesis (i.e., CD105 expression) in the breast cancer experimental lung metastasis model warrants further investigation and clinical translation of dual-labeled TRC105-based agents, which can potentially enable early detection of small metastases and image-guided surgery for tumor removal. PMID:23471463

  8. Molecular imaging of angiogenesis after myocardial infarction by 111In-DTPA-cNGR and 99mTc-sestamibi dual-isotope myocardial SPECT

    OpenAIRE

    Hendrikx, Geert; Saint-Hubert, Marijke De; Dijkgraaf, Ingrid; Bauwens, Matthias; Douma, Kim; Wierts, Roel; Pooters, Ivo; Van den Akker, Nynke MS; Hackeng, Tilman M.; Post, Mark J.; Mottaghy, Felix M.

    2015-01-01

    Background CD13 is selectively upregulated in angiogenic active endothelium and can serve as a target for molecular imaging tracers to non-invasively visualise angiogenesis in vivo. Non-invasive determination of CD13 expression can potentially be used to monitor treatment response to pro-angiogenic drugs in ischemic heart disease. CD13 binds peptides and proteins through binding to tripeptide asparagine-glycine-arginine (NGR) amino acid residues. Previous studies using in vivo fluorescence mi...

  9. PET/SPECT Imaging of Hindlimb Ischemia: Focusing on Angiogenesis and Blood Flow

    OpenAIRE

    Orbay, Hakan; Hong, Hao; Zhang, Yin; Cai, Weibo

    2012-01-01

    Peripheral artery disease (PAD) is a result of the atherosclerotic narrowing of blood vessels to the extremities, and the subsequent tissue ischemia can lead to the up-regulation of angiogenic growth factors and formation of new vessels as a recovery mechanism. Such formation of new vessels can be evaluated with various non-invasive molecular imaging techniques, where serial images from the same subjects can be obtained to allow the documentation of disease progression and therapeutic respons...

  10. Three-dimensional contrast enhanced ultrasound score and dynamic contrast-enhanced magnetic resonance imaging score in evaluating breast tumor angiogenesis: Correlation with biological factors

    International Nuclear Information System (INIS)

    Objective: To explore the clinical value of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) score systems in evaluating breast tumor angiogenesis by comparing their diagnostic efficacy and correlation with biological factors. Methods: 3D-CEUS was performed in 183 patients with breast tumors by Esaote Mylab90 with SonoVue (Bracco, Italy), DCE-MRI was performed on a dedicated breast magnetic resonance imaging (DBMRI) system (Aurora Dedicated Breast MRI Systems, USA) with a dedicated breast coil. 3D-CEUS and DCE-MRI score systems were created based on tumor perfusion and vascular characteristics. Microvessel density (MVD), vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-2, MMP-9) expression were measured by immunohistochemistry. Results: Pathological results showed 35 benign and 148 malignant breast tumors. MVD (P = 0.000, r = 0.76), VEGF (P = 0.000, r = 0.55), MMP-2 (P = 0.000, r = 0.39) and MMP-9 (P = 0.000, r = 0.41) expression were all significantly different between benignity and malignancy. Regarding 3D-CEUS 4 points as cutoff value, the sensitivity, specificity and accuracy were 85.1%, 94.3% and 86.9%, respectively, and correlated well with MVD (P = 0.000, r = 0.50), VEGF (P = 0.000, r = 0.50), MMP-2 (P = 0.000, r = 0.50) and MMP-9 (P = 0.000, r = 0.66). Taking DCE-MRI 5 points as cutoff value, the sensitivity, specificity and accuracy were 86.5%, 94.3% and 88.0%, respectively and also correlated well with MVD (P = 0.000, r = 0.52), VEGF (P = 0.000, r = 0.44), MMP-2 (P = 0.000, r = 0.42) and MMP-9 (P = 0.000, r = 0.35). Conclusions: 3D-CEUS score system displays inspiring diagnostic performance and good agreement with DCE-MRI scoring. Moreover, both score systems correlate well with MVD, VEGF, MMP-2 and MMP-9 expression, and thus have great potentials in tumor angiogenesis evaluation

  11. Three-dimensional contrast enhanced ultrasound score and dynamic contrast-enhanced magnetic resonance imaging score in evaluating breast tumor angiogenesis: Correlation with biological factors

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Wan-Ru, E-mail: jiawanru@126.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Chai, Wei-Min, E-mail: chai_weimin@yahoo.com.cn [Department of Radiology, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Tang, Lei, E-mail: jessietang1003@163.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Wang, Yi, E-mail: xiatian.0602@163.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Fei, Xiao-Chun, E-mail: xcf0222@163.com [Department of Pathology, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Han, Bao-San, E-mail: hanbaosan@126.com [Department of Comprehensive Breast Health Center, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Chen, Man, E-mail: lucyjia1370@126.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China)

    2014-07-15

    Objective: To explore the clinical value of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) score systems in evaluating breast tumor angiogenesis by comparing their diagnostic efficacy and correlation with biological factors. Methods: 3D-CEUS was performed in 183 patients with breast tumors by Esaote Mylab90 with SonoVue (Bracco, Italy), DCE-MRI was performed on a dedicated breast magnetic resonance imaging (DBMRI) system (Aurora Dedicated Breast MRI Systems, USA) with a dedicated breast coil. 3D-CEUS and DCE-MRI score systems were created based on tumor perfusion and vascular characteristics. Microvessel density (MVD), vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-2, MMP-9) expression were measured by immunohistochemistry. Results: Pathological results showed 35 benign and 148 malignant breast tumors. MVD (P = 0.000, r = 0.76), VEGF (P = 0.000, r = 0.55), MMP-2 (P = 0.000, r = 0.39) and MMP-9 (P = 0.000, r = 0.41) expression were all significantly different between benignity and malignancy. Regarding 3D-CEUS 4 points as cutoff value, the sensitivity, specificity and accuracy were 85.1%, 94.3% and 86.9%, respectively, and correlated well with MVD (P = 0.000, r = 0.50), VEGF (P = 0.000, r = 0.50), MMP-2 (P = 0.000, r = 0.50) and MMP-9 (P = 0.000, r = 0.66). Taking DCE-MRI 5 points as cutoff value, the sensitivity, specificity and accuracy were 86.5%, 94.3% and 88.0%, respectively and also correlated well with MVD (P = 0.000, r = 0.52), VEGF (P = 0.000, r = 0.44), MMP-2 (P = 0.000, r = 0.42) and MMP-9 (P = 0.000, r = 0.35). Conclusions: 3D-CEUS score system displays inspiring diagnostic performance and good agreement with DCE-MRI scoring. Moreover, both score systems correlate well with MVD, VEGF, MMP-2 and MMP-9 expression, and thus have great potentials in tumor angiogenesis evaluation.

  12. Angiogenesis Assays.

    Science.gov (United States)

    Nambiar, Dhanya K; Kujur, Praveen K; Singh, Rana P

    2016-01-01

    Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the required nutrient supply and gaseous exchange through blood vessels essentially needed for their sustained and aggressive growth. In order to understand any biological process, it becomes imperative that we use models, which could mimic the actual biological system as closely as possible. Hence, finding the most appropriate model is always a vital part of any experimental design. Angiogenesis research has also been much affected due to lack of simple, reliable, and relevant models which could be easily quantitated. The angiogenesis models have been used extensively for studying the action of various molecules for agonist or antagonistic behaviour and associated mechanisms. Here, we have described two protocols or models which have been popularly utilized for studying angiogenic parameters. Rat aortic ring assay tends to bridge the gap between in vitro and in vivo models. The chorioallantoic membrane (CAM) assay is one of the most utilized in vivo model system for angiogenesis-related studies. The CAM is highly vascularized tissue of the avian embryo and serves as a good model to study the effects of various test compounds on neoangiogenesis. PMID:26608294

  13. Hyperspectral image processing methods

    Science.gov (United States)

    Hyperspectral image processing refers to the use of computer algorithms to extract, store and manipulate both spatial and spectral information contained in hyperspectral images across the visible and near-infrared portion of the electromagnetic spectrum. A typical hyperspectral image processing work...

  14. Image registration method for medical image sequences

    Science.gov (United States)

    Gee, Timothy F.; Goddard, James S.

    2013-03-26

    Image registration of low contrast image sequences is provided. In one aspect, a desired region of an image is automatically segmented and only the desired region is registered. Active contours and adaptive thresholding of intensity or edge information may be used to segment the desired regions. A transform function is defined to register the segmented region, and sub-pixel information may be determined using one or more interpolation methods.

  15. Soft tissue tumors - imaging methods

    International Nuclear Information System (INIS)

    Soft Tissue Tumors - Imaging Methods: Imaging methods play an important diagnostic role in soft tissue tumors concerning a preoperative evaluation of localization, size, topographic relationship, dignity, and metastatic disease. The present paper gives an overview about diagnostic methods available today such as ultrasound, thermography, roentgenographic plain films and xeroradiography, radionuclide methods, computed tomography, lymphography, angiography, and magnetic resonance imaging. Besides sonography particularly computed tomography has the most important diagnostic value in soft tissue tumors. The application of a recently developed method, the magnetic resonance imaging, cannot yet be assessed in its significance. (orig.)

  16. Development of a new structure for in vivo tracers synthesis: application to tumor neo-angiogenesis imaging

    International Nuclear Information System (INIS)

    Molecular imaging is an essential non-invasive tool usable for diagnosis and characterisation of many diseases. Technetium-based tracers are the most popular ones due to availability, cost and radiochemical properties of 99mTc. Nevertheless, effective tracers development requires a long, expensive, and mainly empirical optimisation process. This context prompted us to carry on the development of a new technetium structure which exhibits lots of potential functionalization spots compatible with a combinatorial approach. We synthesised 12 N3X (X = N, O, S) different ligands. Each of them includes a triazole moiety, (formed via a click-chemistry reaction), which is involved in the metal complexation that implies one of its nitrogen atoms. Then we evaluated their ability to readily form oxo-technetium complexes in conditions that are compatible with medical use in hospital. One complex was formed in quantitative yields and its stability in mice plasma was investigated. A complex called TriaS-99mTc, stable to more than 90% after 6 h incubation, was selected. In vivo study of TriaS-99mTc revealed an efficient blood clearance via the urinary excretion pathway with very low degradation. As an application, we used this structure for the development of tracers that target integrin αvβ3, a known bio-marker of tumor neo-angiogenesis. First, we synthesised functionalized TriaS-based integrated complexes. Functional modification of TriaS by addition of side chains and substituents did not affect its ability to chelate oxo-technetium quantitatively. In addition, its stability in mice plasma was satisfactory. We also developed a bifunctional approach using c(RGDfK) peptide as the targeting biomolecule. In this way, a variable moiety (herein a PEG moiety) can be inserted in the structure through click-chemistry in order to modulate tracers solubility, biodistribution and excretion. (author)

  17. Computational methods for molecular imaging

    CERN Document Server

    Shi, Kuangyu; Li, Shuo

    2015-01-01

    This volume contains original submissions on the development and application of molecular imaging computing. The editors invited authors to submit high-quality contributions on a wide range of topics including, but not limited to: • Image Synthesis & Reconstruction of Emission Tomography (PET, SPECT) and other Molecular Imaging Modalities • Molecular Imaging Enhancement • Data Analysis of Clinical & Pre-clinical Molecular Imaging • Multi-Modal Image Processing (PET/CT, PET/MR, SPECT/CT, etc.) • Machine Learning and Data Mining in Molecular Imaging. Molecular imaging is an evolving clinical and research discipline enabling the visualization, characterization and quantification of biological processes taking place at the cellular and subcellular levels within intact living subjects. Computational methods play an important role in the development of molecular imaging, from image synthesis to data analysis and from clinical diagnosis to therapy individualization. This work will bring readers fro...

  18. Live imaging of cysteine-cathepsin activity reveals dynamics of focal inflammation, angiogenesis, and polyp growth.

    Directory of Open Access Journals (Sweden)

    Elias Gounaris

    Full Text Available It has been estimated that up to 30% of detectable polyps in patients regress spontaneously. One major challenge in the evaluation of effective therapy of cancer is the readout for tumor regression and favorable biological response to therapy. Inducible near infra-red (NIR fluorescent probes were utilized to visualize intestinal polyps of mice hemizygous for a novel truncation of the Adenomatous Polyposis coli (APC gene. Laser Scanning Confocal Microscopy in live mice allowed visualization of cathepsin activity in richly vascularized benign dysplastic lesions. Using biotinylated suicide inhibitors we quantified increased activities of the Cathepsin B & Z in the polyps. More than (3/4 of the probe signal was localized in CD11b(+Gr1(+ myeloid derived suppressor cells (MDSC and CD11b(+F4/80(+ macrophages infiltrating the lesions. Polyposis was attenuated through genetic ablation of cathepsin B, and suppressed by neutralization of TNFalpha in mice. In both cases, diminished probe signal was accounted for by loss of MDSC. Thus, in vivo NIR imaging of focal cathepsin activity reveals inflammatory reactions etiologically linked with cancer progression and is a suitable approach for monitoring response to therapy.

  19. An Image Registration Method for Colposcopic Images

    Directory of Open Access Journals (Sweden)

    Efrén Mezura-Montes

    2013-01-01

    sequence and a division of such image into small windows. A search process is then carried out to find the window with the highest affinity in each image of the sequence and replace it with the window in the reference image. The affinity value is based on polynomial approximation of the time series computed and the search is bounded by a search radius which defines the neighborhood of each window. The proposed approach is tested in ten 310-frame real cases in two experiments: the first one to determine the best values for the window size and the search radius and the second one to compare the best obtained results with respect to four registration methods found in the specialized literature. The obtained results show a robust and competitive performance of the proposed approach with a significant lower time with respect to the compared methods.

  20. Positron Emission Tomography Imaging of Tumor Angiogenesis with a 61/64Cu-Labeled F(ab')2 Antibody Fragment

    OpenAIRE

    Hong, Hao; Zhang, Yin; Orbay, Hakan; Valdovinos, Hector F.; Nayak, Tapas R.; Bean, Jero; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo

    2013-01-01

    The objective of this study was to characterize the in vitro and in vivo properties of the F(ab')2 fragment of TRC105, a human/murine chimeric IgG1 monoclonal antibody that binds with high avidity to human and murine CD105 (i.e. endoglin), and investigate its potential for positron emission tomography (PET) imaging of tumor angiogenesis after 61/64Cu-labeling. TRC105-F(ab')2 of high purity was produced by pepsin digestion of TRC105, which was confirmed by SDS-PAGE, HPLC analysis, and mass spe...

  1. One-step radiosynthesis of 18F-AlF-NOTA-RGD2 for tumor angiogenesis PET imaging

    International Nuclear Information System (INIS)

    One of the major obstacles of the clinical translation of 18F-labeled arginine-glycine-aspartic acid (RGD) peptides has been the laborious multistep radiosynthesis. In order to facilitate the application of RGD-based positron emission tomography (PET) probes in the clinical setting we investigated in this study the feasibility of using the chelation reaction between Al18F and a macrocyclic chelator-conjugated dimeric RGD peptide as a simple one-step 18F labeling strategy for development of a PET probe for tumor angiogenesis imaging. Dimeric cyclic peptide E[c(RGDyK)]2 (RGD2) was first conjugated with a macrocyclic chelator, 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), and the resulting bioconjugate NOTA-RGD2 was then radiofluorinated via Al18F intermediate to synthesize 18F-AlF-NOTA-RGD2. Integrin binding affinities of the peptides were assessed by a U87MG cell-based receptor binding assay using 125I-echistatin as the radioligand. The tumor targeting efficacy and in vivo profile of 18F-AlF-NOTA-RGD2 were further evaluated in a subcutaneous U87MG glioblastoma xenograft model by microPET and biodistribution. NOTA-RGD2 was successfully 18F-fluorinated with good yield within 40 min using the Al18F intermediate. The IC50 of 19F-AlF-NOTA-RGD2 was determined to be 46 ± 4.4 nM. Quantitative microPET studies demonstrated that 18F-AlF-NOTA-RGD2 showed high tumor uptake, fast clearance from the body, and good tumor to normal organ ratios. NOTA-RGD2 bioconjugate has been successfully prepared and labeled with Al18F in one single step of radiosynthesis. The favorable in vivo performance and the short radiosynthetic route of 18F-AlF-NOTA-RGD2 warrant further optimization of the probe and the radiofluorination strategy to accelerate the clinical translation of 18F-labeled RGD peptides. (orig.)

  2. In Vivo CEST MR imaging of U87 mice brain tumor angiogenesis using targeted LipoCEST contrast agent at 7 T

    International Nuclear Information System (INIS)

    LipoCEST are liposome-encapsulating paramagnetic contrast agents (CA) based on chemical exchange saturation transfer with applications in bio-molecular MRI. Their attractive features include biocompatibility, sub-nanomolar sensitivity, and amenability to functionalization for targeting bio-markers. We demonstrate MR imaging using a targeted lipoCEST, injected intravenously. A lipoCEST carrying Tm(III)-complexes was conjugated to RGD tripeptide (RGD-lipoCEST), to target integrin αv,β3 receptors involved in tumor angiogenesis and was compared with an unconjugated lipoCEST. Brain tumors were induced in athymic nude mice by intracerebral injection of U87MG cells and were imaged at 7 T after intravenous injection of either of the two contrast agents (n = 12 for each group). Chemical exchange saturation transfer-MSME sequence was applied over 2 h with an average acquisition time interval of 13.5 min. The chemical exchange saturation transfer signal was ∼1% in the tumor and controlateral regions, and decreased to ∼0.3% after 2 h; while RGD-lipoCEST signal was ∼1.4% in the tumor region and persisted for up to 2 h. Immunohistochemical staining revealed a persistent co-localization of RGD-lipoCEST with αv,β3 receptors in the tumor region. These results constitute an encouraging step toward in vivo MRI imaging of tumor angiogenesis using intravenously injected lipoCEST. (authors)

  3. Image restoration and processing methods

    International Nuclear Information System (INIS)

    This review will stress the importance of using image restoration techniques that deal with incomplete, inconsistent, and noisy data and do not introduce spurious features into the processed image. No single image is equally suitable for both the resolution of detail and the accurate measurement of intensities. A good general purpose technique is the maximum entropy method and the basis and use of this will be explained. (orig.)

  4. Projective Methods of Image Recognition

    OpenAIRE

    Putyatin, Yevgeniy; Gorohovatsky, Vladimir; Gorohovatsky, Alexey; Peredriy, Elena

    2008-01-01

    We propose a method for image recognition on the base of projections. Radon transform gives an opportunity to map image into space of its projections. Projection properties allow constructing informative features on the base of moments that can be successfully used for invariant recognition. Offered approach gives about 91-97% of correct recognition.

  5. Imaging methods in oncology

    International Nuclear Information System (INIS)

    Recent technological advances have given new tools to the clinician, and in this review four diagnostic approaches are detailed - staging of lung cancer by computed tomography (CT), radiation therapy planning with CT, follow-up with magnetic resonance spectroscopy and follow-up of colorectal malignancies with positron emission tomography. The present status and future prospects of each method are discussed. (author)

  6. Twin-Foucault imaging method

    Science.gov (United States)

    Harada, Ken

    2012-02-01

    A method of Lorentz electron microscopy, which enables observation two Foucault images simultaneously by using an electron biprism instead of an objective aperture, was developed. The electron biprism is installed between two electron beams deflected by 180° magnetic domains. Potential applied to the biprism deflects the two electron beams further, and two Foucault images with reversed contrast are then obtained in one visual field. The twin Foucault images are able to extract the magnetic domain structures and to reconstruct an ordinary electron micrograph. The developed Foucault method was demonstrated with a 180° domain structure of manganite La0.825Sr0.175MnO3.

  7. Image portion identification methods, image parsing methods, image parsing systems, and articles of manufacture

    Science.gov (United States)

    Lassahn, Gordon D.; Lancaster, Gregory D.; Apel, William A.; Thompson, Vicki S.

    2013-01-08

    Image portion identification methods, image parsing methods, image parsing systems, and articles of manufacture are described. According to one embodiment, an image portion identification method includes accessing data regarding an image depicting a plurality of biological substrates corresponding to at least one biological sample and indicating presence of at least one biological indicator within the biological sample and, using processing circuitry, automatically identifying a portion of the image depicting one of the biological substrates but not others of the biological substrates.

  8. Fast regularized image interpolation method

    Institute of Scientific and Technical Information of China (English)

    Hongchen Liu; Yong Feng; Linjing Li

    2007-01-01

    The regularized image interpolation method is widely used based on the vector interpolation model in which down-sampling matrix has very large dimension and needs large storage consumption and higher computation complexity. In this paper, a fast algorithm for image interpolation based on the tensor product of matrices is presented, which transforms the vector interpolation model to matrix form. The proposed algorithm can extremely reduce the storage requirement and time consumption. The simulation results verify their validity.

  9. Positron Emission Tomography Imaging of Angiogenesis in a Murine Hindlimb Ischemia Model with 64Cu-Labeled TRC105

    OpenAIRE

    Orbay, Hakan; Zhang, Yin; Hong, Hao; Hacker, Timothy A.; Valdovinos, Hector F.; Zagzebski, James A; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo

    2013-01-01

    The goal of this study was to assess ischemia-induced angiogenesis with 64Cu-NOTA-TRC105 positron emission tomography (PET) in a murine hindlimb ischemia model of peripheral artery disease (PAD). CD105 binding affinity/specificity of NOTA-conjugated TRC105 (an anti-CD105 antibody) was evaluated by flow cytometry, which exhibited no difference from unconjugated TRC105. BALB/c mice were anesthetized and the right femoral artery was ligated to induce hindlimb ischemia, with the left hindlimb ser...

  10. Dynamic Contrast-Enhanced Magnetic Resonance Imaging Reveals Stress-Induced Angiogenesis in MCF7 Human Breast Tumors

    Science.gov (United States)

    Furman-Haran, Edna; Margalit, Raanan; Grobgeld, Dov; Degani, Hadassa

    1996-06-01

    The mechanism of contrast enhancement of tumors using magnetic resonance imaging was investigated in MCF7 human breast cancer implanted in nude mice. Dynamic contrast-enhanced images recorded at high spatial resolution were analyzed by an image analysis method based on a physiological model, which included the blood circulation, the tumor, the remaining tissues, and clearance via the kidneys. This analysis enabled us to map in rapidly enhancing regions within the tumor, the capillary permeability factor (capillary permeability times surface area per voxel volume) and the fraction of leakage space. Correlation of these maps with T2-weighted spin echo images, with histopathology, and with immunohistochemical staining of endothelial cells demonstrated the presence of dense permeable microcapillaries in the tumor periphery and in intratumoral regions that surrounded necrotic loci. The high leakage from the intratumoral permeable capillaries indicated an induction of a specific angiogenic process associated with stress conditions that cause necrosis. This induction was augmented in tumors responding to tamoxifen treatment. Determination of the distribution and extent of this stress-induced angiogenic activity by contrast-enhanced MRI might be of diagnostic and of prognostic value.

  11. Photoacoustic molecular imaging of angiogenesis using theranostic ανβ3-targeted copper nanoparticles incorporating a sn-2 lipase-labile fumagillin prodrug

    Science.gov (United States)

    Zhang, Ruiying; Cai, Xin; Yang, Xiaoxia; Senpan, Angana; Allen, John S.; Pan, Dipanjan; Lanza, Gregory M.; Wang, Lihong V.

    2014-03-01

    Photoacoustic (PA) tomography imaging is an emerging, versatile, and noninvasive imaging modality, which combines the advantages of both optical imaging and ultrasound imaging. It opens up opportunities for noninvasive imaging of angiogenesis, a feature of skin pathologies including cancers and psoriasis. In this study, high-density copper oleate encapsulated within a phospholipid surfactant (CuNPs) generated a soft nanoparticle with PA contrast comparable to gold. Within the near-infrared window, the copper nanoparticles can provide a signal more than 7 times higher that of blood. ανβ3-targeted of CuNPs in a Matrigel mouse model demonstrated prominent PA contrast enhancement of the neovasculature compared to mice given nontargeted or competitively inhibited CuNPs. Incorporation of a sn-2 lipase-labile fumagillin prodrug into the CuNPs produced marked antiangiogenesis in the same model, demonstrating the theranostic potential of a PA agent for the first time in vivo. With a PA signal comparable to gold-based nanoparticles yet a lower cost and demonstrated drug delivery potential, ανβ3-targeted CuNPs hold great promise for the management of skin pathologies with neovascular features.

  12. In vitro and in vivo imaging of prostate cancer angiogenesis using anti-vascular endothelial growth factor receptor 2 antibody-conjugated quantum dot

    International Nuclear Information System (INIS)

    Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.

  13. In vitro and in vivo imaging of prostate cancer angiogenesis using anti-vascular endothelial growth factor receptor 2 antibody-conjugated quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Haejin; Lee, Jiyeon; Song, Rita; Lee, Jung Han [Medicinal Chemistry Laboratory, Institute Pasteur Korea (IP-K), Seongnam (Korea, Republic of); Hwang, Sung Il; Lee, Hak Jong [Seoul National University Bundang Hospital, Institute of Radiation Medicine, Seoul National University Medical Research Center, Clinical Research Institute, Seongnam (Korea, Republic of); Kim, Young Hwa [Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.

  14. Modelling approaches for angiogenesis.

    Science.gov (United States)

    Taraboletti, G; Giavazzi, R

    2004-04-01

    The development of a functional vasculature within a tumour is a requisite for its growth and progression. This fact has led to the design of therapies directed toward the tumour vasculature, aiming either to prevent the formation of new vessels (anti-angiogenic) or to damage existing vessels (vascular targeting). The development of agents with different mechanisms of action requires powerful preclinical models for the analysis and optimization of these therapies. This review concerns 'classical' assays of angiogenesis in vitro and in vivo, recent approaches to target identification (analysis of gene and protein expression), and the study of morphological and functional changes in the vasculature in vivo (imaging techniques). It mainly describes assays designed for anti-angiogenic compounds, indicating, where possible, their application to the study of vascular-targeting agents. PMID:15120043

  15. Imaging methods for ovarian tumours

    International Nuclear Information System (INIS)

    The present paper compares the results of MRT with sonography in 64 patients with tumours of the adnexa in 35 patients examined by CT. There was no difference between these three imaging methods as regards lateralisation of the lesion. MRT provided better differentiation because of the excellent demonstration of the uterus and of tumours of the adnexa. Detailed tissue characterisation, particularly as regards cystic lesions, provides improved diagnostic information. MRT has problems, however, because of its low spatial resolution and the difficulty in differentiation from bowel loops. At present sonography and CT is better at establishing a differential diagnosis. CT remains the method of choice for tumour staging. (orig.)

  16. Digital image processing mathematical and computational methods

    CERN Document Server

    Blackledge, J M

    2005-01-01

    This authoritative text (the second part of a complete MSc course) provides mathematical methods required to describe images, image formation and different imaging systems, coupled with the principle techniques used for processing digital images. It is based on a course for postgraduates reading physics, electronic engineering, telecommunications engineering, information technology and computer science. This book relates the methods of processing and interpreting digital images to the 'physics' of imaging systems. Case studies reinforce the methods discussed, with examples of current research

  17. Mediators of ocular angiogenesis

    Indian Academy of Sciences (India)

    Yureeda Qazi; Surekha Maddula; Balamurali K. Ambati

    2009-12-01

    Angiogenesis is the formation of new blood vessels from pre-existing vasculature. Pathologic angiogenesis in the eye can lead to severe visual impairment. In our review, we discuss the roles of both pro-angiogenic and anti-angiogenic molecular players in corneal angiogenesis, proliferative diabetic retinopathy, exudative macular degeneration and retinopathy of prematurity, highlighting novel targets that have emerged over the past decade.

  18. Photoacoustic microscopy for quantitative evaluation of angiogenesis inhibitor

    Science.gov (United States)

    Chen, Sung-Liang; Burnett, Joseph; Sun, Duxin; Xie, Zhixing; Wang, Xueding

    2014-03-01

    We present the photoacoustic microscopy (PAM) for evaluation of angiogenesis inhibitors on a chick embryo model. Microvasculature in the chorioallantoic membrane (CAM) of the chick embryos was imaged by PAM, and the optical microscopy (OM) images of the same set of CAMs were also acquired for comparisons, serving for validation of the results from PAM. The angiogenesis inhibitors, Sunitinib, with different concentrations applied to the CAM result in the change in microvascular density, which was quantified by both PAM and OM imaging. Similar change in microvascular density from PAM and OM imaging in response to angiogenesis inhibitor at different doses was observed, demonstrating that PAM has potential to provide objective evaluation of anti-angiogenesis medication. Besides, PAM is advantageous in three-dimensional and functional imaging compared with OM so that the emerging PAM technique may offer unique information on the efficacy of angiogenesis inhibitors and could benefit applications related to antiangiogenesis treatments.

  19. Method of assessing heterogeneity in images

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Richard E.; Carson, James P.

    2016-08-23

    A method of assessing heterogeneity in images is disclosed. 3D images of an object are acquired. The acquired images may be filtered and masked. Iterative decomposition is performed on the masked images to obtain image subdivisions that are relatively homogeneous. Comparative analysis, such as variogram analysis or correlogram analysis, is performed of the decomposed images to determine spatial relationships between regions of the images that are relatively homogeneous.

  20. Trauma Radiology Companion: methods, guidelines, imaging fundamentals

    International Nuclear Information System (INIS)

    The book contains two sections: (1). Traumatological reference data, epidemiology of traumata.(2). Imaging fundamentals, reference data for trauma assessment, imaging of brain and vertebrae, body upper extremities and pelvis. Comparative assessment of available imaging methods: X-ray, MRI, CT, nuclear imaging methods, ultrasound

  1. Thiol-PEG-carboxyl-stabilized Fe{sub 2}O{sub 3}/Au nanoparticles targeted to CD105: Synthesis, characterization and application in MR imaging of tumor angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Song; Gong, Mingfu; Zhang, Dong; Yang, Hua [Department of Radiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China); Gao, Fabao [Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041 (China); Zou, Liguang, E-mail: zlgxqyy@163.com [Department of Radiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China)

    2014-07-15

    Objective: To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe{sub 2}O{sub 3}/Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI). Methods: Fe{sub 2}O{sub 3}/Au nanoparticles (hybrids) were prepared by reducing Au{sup 3+} on the surface of Fe{sub 2}O{sub 3} nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo. Results: The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SI{sub R}) was positively correlated with the tumor MVD (R{sup 2} = 0.8972). Conclusion: Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe{sub 2}O{sub 3}/Au nanoparticles can efficiently target CD105 expressed

  2. Soliton driven angiogenesis

    Science.gov (United States)

    Bonilla, L. L.; Carretero, M.; Terragni, F.; Birnir, B.

    2016-08-01

    Angiogenesis is a multiscale process by which blood vessels grow from existing ones and carry oxygen to distant organs. Angiogenesis is essential for normal organ growth and wounded tissue repair but it may also be induced by tumours to amplify their own growth. Mathematical and computational models contribute to understanding angiogenesis and developing anti-angiogenic drugs, but most work only involves numerical simulations and analysis has lagged. A recent stochastic model of tumour-induced angiogenesis including blood vessel branching, elongation, and anastomosis captures some of its intrinsic multiscale structures, yet allows one to extract a deterministic integropartial differential description of the vessel tip density. Here we find that the latter advances chemotactically towards the tumour driven by a soliton (similar to the famous Korteweg-de Vries soliton) whose shape and velocity change slowly. Analysing these collective coordinates paves the way for controlling angiogenesis through the soliton, the engine that drives this process.

  3. Adjustable compression method for still JPEG images

    OpenAIRE

    Mora Pascual, Jerónimo Manuel; Mora Mora, Higinio; Fuster Guilló, Andrés; Azorín López, Jorge

    2015-01-01

    There are a large number of image processing applications that work with different performance requirements and available resources. Recent advances in image compression focus on reducing image size and processing time, but offer no real-time solutions for providing time/quality flexibility of the resulting image, such as using them to transmit the image contents of web pages. In this paper we propose a method for encoding still images based on the JPEG standard that allows the compression/de...

  4. Positron Emission Tomography Imaging of Tumor Angiogenesis with a 61/64Cu-Labeled F(ab')2 Antibody Fragment

    Science.gov (United States)

    Hong, Hao; Zhang, Yin; Orbay, Hakan; Valdovinos, Hector F.; Nayak, Tapas R.; Bean, Jero; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo

    2013-01-01

    The objective of this study was to characterize the in vitro and in vivo properties of the F(ab')2 fragment of TRC105, a human/murine chimeric IgG1 monoclonal antibody that binds with high avidity to human and murine CD105 (i.e. endoglin), and investigate its potential for positron emission tomography (PET) imaging of tumor angiogenesis after 61/64Cu-labeling. TRC105-F(ab')2 of high purity was produced by pepsin digestion of TRC105, which was confirmed by SDS-PAGE, HPLC analysis, and mass spectrometry. 61/64Cu-labeling of NOTA-TRC105-F(ab')2 (NOTA denotes 1,4,7-triazacyclononane-1,4,7-triacetic acid) was achieved with yields of > 75% (specific activity: ~115 GBq/μmol). PET imaging revealed rapid tumor uptake of 64Cu-NOTA TRC105-F(ab')2 in the 4T1 murine breast cancer model (5.8 ± 0.8, 7.6 ± 0.6, 5.6 ± 0.4, 5.0 ± 0.6, and 3.8 ± 0.7 %ID/g at 0.5, 3, 16, 24, and 48 h post-injection respectively; n = 4). Since tumor uptake peaked at 3 h post-injection, 61Cu-NOTA-TRC105-F(ab')2 also gave good tumor contrast at 3 and 8 h post-injection. CD105 specificity of the tracers was confirmed by blocking studies and histopathology. In conclusion, the use of a F(ab')2 fragment led to more rapid tumor uptake (which peaked at 3 h post-injection) than radiolabeled intact antibody (which often peaked after 24 h post-injection), which may allow for same day immunoPET imaging in future clinical studies. PMID:23316869

  5. Positron emission tomography imaging of tumor angiogenesis with a (61/64)Cu-labeled F(ab')(2) antibody fragment.

    Science.gov (United States)

    Hong, Hao; Zhang, Yin; Orbay, Hakan; Valdovinos, Hector F; Nayak, Tapas R; Bean, Jero; Theuer, Charles P; Barnhart, Todd E; Cai, Weibo

    2013-02-01

    The objective of this study was to characterize the in vitro and in vivo properties of the F(ab')(2) fragment of TRC105, a human/murine chimeric IgG1 monoclonal antibody that binds with high avidity to human and murine CD105 (i.e., endoglin), and investigate its potential for positron emission tomography (PET) imaging of tumor angiogenesis after (61/64)Cu-labeling. TRC105-F(ab')(2) of high purity was produced by pepsin digestion of TRC105, which was confirmed by SDS-PAGE, HPLC analysis, and mass spectrometry. (61/64)Cu-labeling of NOTA-TRC105-F(ab')(2) (NOTA denotes 1,4,7-triazacyclononane-1,4,7-triacetic acid) was achieved with yields of >75% (specific activity: ∼115 GBq/μmol). PET imaging revealed rapid tumor uptake of (64)Cu-NOTA-TRC105-F(ab')(2) in the 4T1 murine breast cancer model (5.8 ± 0.8, 7.6 ± 0.6, 5.6 ± 0.4, 5.0 ± 0.6, and 3.8 ± 0.7% ID/g at 0.5, 3, 16, 24, and 48 h postinjection respectively; n = 4). Since tumor uptake peaked at 3 h postinjection, (61)Cu-NOTA-TRC105-F(ab')(2) also gave good tumor contrast at 3 and 8 h postinjection. CD105 specificity of the tracers was confirmed by blocking studies and histopathology. In conclusion, the use of a F(ab')(2) fragment led to more rapid tumor uptake (which peaked at 3 h postinjection) than radiolabeled intact antibody (which often peaked after 24 h postinjection), which may allow for same day immunoPET imaging in future clinical studies. PMID:23316869

  6. Biomarkers of Angiogenesis in Colorectal Cancer

    OpenAIRE

    Luay Mousa; Salem, Mohamed E.; Sameh Mikhail

    2015-01-01

    Colorectal cancer (CRC) is the third most common cancer worldwide and accounts for 10% of all new cancer diagnoses. Angiogenesis is a tightly regulated process that is mediated by a group of angiogenic factors such as vascular endothelial growth factor and its receptors. Given the widespread use of antiangiogenic agents in CRC, there has been considerable interest in the development of methods to identify novel markers that can predict outcome in the treatment of this disease with angiogenesi...

  7. Angiogenesis and liver fibrosis

    Institute of Scientific and Technical Information of China (English)

    Gülsüm ?zlem Elpek

    2015-01-01

    Recent data indicate that hepatic angiogenesis,regardless of the etiology, takes place in chronic liverdiseases (CLDs) that are characterized by inflammationand progressive fibrosis. Because antiangiogenictherapy has been found to be efficient inthe prevention of fibrosis in experimental models ofCLDs, it is suggested that blocking angiogenesis couldbe a promising therapeutic option in patients withadvanced fibrosis. Consequently, efforts are beingdirected to revealing the mechanisms involved inangiogenesis during the progression of liver fibrosis.Literature evidences indicate that hepatic angiogenesisand fibrosis are closely related in both clinical andexperimental conditions. Hypoxia is a major inducer ofangiogenesis together with inflammation and hepaticstellate cells. These profibrogenic cells stand at theintersection between inflammation, angiogenesis andfibrosis and play also a pivotal role in angiogenesis.This review mainly focuses to give a clear view on therelevant features that communicate angiogenesis withprogression of fibrosis in CLDs towards the-end point ofcirrhosis that may be translated into future therapies.The pathogenesis of hepatic angiogenesis associatedwith portal hypertension, viral hepatitis, non-alcoholicfatty liver disease and alcoholic liver disease are alsodiscussed to emphasize the various mechanisms involvedin angiogenesis during liver fibrogenesis.

  8. Comparative Study of Image Registration Methods

    Directory of Open Access Journals (Sweden)

    Supriya S. Kothalkar

    2014-06-01

    Full Text Available The main objective of image registration is to match two or more images captured at different times by different sensors or by different angles or from different viewpoints. Image registration has become a crucial step in most of the image processing tasks used in various areas. It is a key technology which is applied for computer vision, remote sensing, image processing, medical image analysis and other fields. Medical image registration is used to find a spatial transformation to match all the anatomical points and diagnostic points on the image. In general, the majority of registration methods consist of the following four steps: feature extraction, feature matching, transform modeling, and finally image resampling. The accuracy of a registration process is highly dependent to the feature extraction and matching methods. Cross Correlation is the basic statistical approach to image registration. It is used for template matching or pattern recognition. Template is considered as a sub-image from the reference image, and the image is considered as a sensed image. The objective is to establish the correspondence between the reference image and sensed image. It gives the measure of the degree of similarity between an image and template, which can be used for image registration. Normalized Cross Correlation (NCC method is improved by using Feature Based Method. Image are effectively represented by any of its feature such as edges, points, curves etc. and these features are effectively used for image registration. Images are applied with the filters to extract edges. Post that NCC is done to find the sharp point on NCC plot. This method restricts us with only monomodal images. For multimodal images we have used Mutual Information as a measure of similarity. A widely used measure is Mutual Information (MI. This method requires estimating joint histogram of the two images. Experiments are presented that demonstrate the approach. The technique is

  9. Imaging tumor angiogenesis in breast cancer experimental lung metastasis with positron emission tomography, near-infrared fluorescence, and bioluminescence

    OpenAIRE

    Zhang, Yin; Hong, Hao; Nayak, Tapas R.; Valdovinos, Hector F.; Myklejord, Duane V.; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo

    2013-01-01

    The goal of this study was to develop a molecular imaging agent that can allow for both positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging of CD105 expression in metastatic breast cancer. TRC105, a chimeric anti-CD105 monoclonal antibody, was labeled with both a NIRF dye (i.e., IRDye 800CW) and 64Cu to yield 64Cu-NOTA-TRC105-800CW. Flow cytometry analysis revealed no difference in CD105 binding affinity/specificity between TRC105 and NOTA-TRC105-800CW. Serial bio...

  10. Angiogenesis and tumor

    Directory of Open Access Journals (Sweden)

    Kamran Mansouri

    2010-12-01

    Full Text Available Angiogenesis, the process of new blood vessel formation from existing ones, plays an important role in the physiologic circumstances such as embryonic development, placenta formation, and wound healing. It is also crucial to progress of pathogenic processes of a variety of disorders, including tumor growth and metastasis. In general, angiogenesis process is a multi-factorial and highly structured sequence of cellular events comprising migration, proliferation and differentiation of endothelial cells and finally vascular formation, maturation and remodeling.Thereby, angiogenesis inhibition as a helping agent to conventional therapies such as chemotherapy and radiation has attracted the scientists’ attentions studying in this field.

  11. Angiogenesis and Melanoma

    International Nuclear Information System (INIS)

    Angiogenesis occurs in pathological conditions, such as tumors, where a specific critical point in tumor progression is the transition from the avascular to the vascular phase. Tumor angiogenesis depends mainly on the release by neoplastic cells of growth factors specific for endothelial cells, which are able to stimulate the growth of the host’s blood vessels. This article summarizes the literature concerning the relationship between angiogenesis and human melanoma progression. The recent applications of antiangiogenic agents which interfere with melanoma progression are also described

  12. Lossless Digital Image Compression Method for Bitmap Images

    CERN Document Server

    Meyyappan, Dr T; Nachiaban, N M Jeya; 10.5121/ijma.2011.3407

    2011-01-01

    In this research paper, the authors propose a new approach to digital image compression using crack coding This method starts with the original image and develop crack codes in a recursive manner, marking the pixels visited earlier and expanding the entropy in four directions. The proposed method is experimented with sample bitmap images and results are tabulated. The method is implemented in uni-processor machine using C language source code.

  13. Fast neutron imaging device and method

    Science.gov (United States)

    Popov, Vladimir; Degtiarenko, Pavel; Musatov, Igor V.

    2014-02-11

    A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention.

  14. Fast neutron imaging device and method

    International Nuclear Information System (INIS)

    A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention

  15. Angiogenesis in vestibular schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh;

    2010-01-01

    Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) are potent mediators of tumor angiogenesis. It has been demonstrated that vestibular schwannoma VEGF expression correlates with tumor growth pattern, whereas knowledge on the expression of MMPs is lacking. This study...

  16. MicroPET imaging of brain tumor angiogenesis with {sup 18}F-labeled PEGylated RGD peptide

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoyuan; Park, Ryan; Hou, Yingping; Tohme, Michel; Bading, James R.; Conti, Peter S. [PET Imaging Science Center, Department of Radiology, University of Southern California Keck School of Medicine, 1510 San Pablo St., Suite 350, CA 90033, Los Angeles (United States); Khankaldyyan, Vazgen; Gonzales-Gomez, Ignacio; Laug, Walter E. [Department of Pediatrics, Childrens Hospital Los Angeles, CA 90027, Los Angeles (United States)

    2004-08-01

    We have previously labeled cyclic RGD peptide c(RGDyK) with fluorine-18 through conjugation labeling via a prosthetic 4-[{sup 18}F]fluorobenzoyl moiety and applied this [{sup 18}F]FB-RGD radiotracer for {alpha}{sub v}-integrin expression imaging in different preclinical tumor models with good tumor-to-background contrast. However, the unfavorable hepatobiliary excretion and rapid tumor washout rate of this tracer limit its potential clinical applications. The aims of this study were to modify the [{sup 18}F]FB-RGD tracer by inserting a heterobifunctional poly(ethylene glycol) (PEG, M.W. =3,400) between the {sup 18}F radiolabel and the RGD moiety and to test this [{sup 18}F]FB-PEG-RGD tracer for brain tumor targeting and in vivo kinetics. [{sup 18}F]FB-PEG-RGD was prepared by coupling the RGD-PEG conjugate with N-succinimidyl 4-[{sup 18}F]fluorobenzoate ([{sup 18}F]SFB) under slightly basic conditions (pH=8.5). The radiochemical yield was about 20-30% based on the active ester [{sup 18}F]SFB, and specific activity was over 100 GBq/{mu}mol. This tracer had fast blood clearance, rapid and high tumor uptake in the subcutaneous U87MG glioblastoma model (5.2{+-}0.5%ID/g at 30 min p.i.). Moderately rapid tumor washout was observed, with the activity accumulation decreased to 2.2{+-}0.4%ID/g at 4 h p.i. MicroPET and autoradiography imaging showed a very high tumor-to-background ratio and limited activity accumulation in the liver, kidneys and intestinal tracts. U87MG tumor implanted into the mouse forebrain was well visualized with [{sup 18}F]FB-PEG-RGD. Although uptake in the orthotopic tumor was significantly lower (P<0.01) than in the subcutaneous tumor, the maximum tumor-to-brain ratio still reached 5.0{+-}0.6 due to low normal brain background. The results of H and E staining post mortem agreed with the anatomical information obtained from non-invasive microPET imaging. In conclusion, PEGylation suitably modifies the physiological behavior of the RGD peptide. [{sup 18

  17. In vivo tumor angiogenesis imaging with site-specific labeled {sup 99m}Tc-HYNIC-VEGF

    Energy Technology Data Exchange (ETDEWEB)

    Blankenberg, Francis G. [Stanford University, Division of Nuclear Medicine/Department of Radiology and MIPS (Molecular Imaging Program at Stanford), Stanford, CA (United States); Stanford University, Department of Pediatrics, Stanford, CA (United States); Backer, Marina V.; Patel, Vimalkumar; Backer, Joseph M. [SibTech, Inc., Newington, CT (United States); Levashova, Zoia [Stanford University, Division of Nuclear Medicine/Department of Radiology and MIPS (Molecular Imaging Program at Stanford), Stanford, CA (United States)

    2006-07-15

    We recently developed a cysteine-containing peptide tag (C-tag) that allows for site-specific modification of C-tag-containing fusion proteins with a bifunctional chelator, HYNIC (hydrazine nicotinamide)-maleimide. We then constructed and expressed C-tagged vascular endothelial growth factor (VEGF) and labeled it with HYNIC. We wished to test {sup 99m}Tc-HYNIC-C-tagged VEGF ({sup 99m}Tc-HYNIC-VEGF) for the imaging of tumor vasculature before and after antiangiogenic (low continuous dosing, metronomic) and tumoricidal (high-dose) cyclophosphamide treatment. HYNIC-maleimide was reacted with the two thiol groups of C-tagged VEGF without any effect on biologic activity in vitro. {sup 99m}Tc-HYNIC-VEGF was prepared using tin/tricine as an exchange reagent, and injected via the tail vein (200-300 {mu}Ci, 1-2 {mu}g protein) followed by microSPECT imaging 1 h later. Sequencing analysis of HYNIC-containing peptides obtained after digestion confirmed the site-specific labeling of the two accessible thiol groups of C-tagged VEGF. Tumor vascularity was easily visualized with {sup 99m}Tc/VEGF in Balb/c mice with 4T1 murine mammary carcinoma 10 days after implantation into the left axillary fat pad in controls (12.3{+-}5.0 tumor/bkg, n=27) along with its decrease following treatment with high (150 mg/kg q.o.d. x 4; 1.14{+-}0.48 tumor/bkg, n=9) or low (25 mg/kg q.d. x 7; 1.03{+-}0.18 tumor/bkg, n=9) dose cyclophosphamide. Binding specificity was confirmed by observing a 75% decrease in tumor uptake of {sup 99m}Tc/biotin-inactivated VEGF, as compared with {sup 99m}Tc-HYNIC-VEGF. {sup 99m}Tc can be loaded onto C-tagged VEGF in a site-specific fashion without reducing its bioactivity. {sup 99m}Tc-HYNIC-VEGF can be rapidly prepared for the imaging of tumor vasculature and its response to different types of chemotherapy. (orig.)

  18. Review methods for image segmentation from computed tomography images

    International Nuclear Information System (INIS)

    Image segmentation is a challenging process in order to get the accuracy of segmentation, automation and robustness especially in medical images. There exist many segmentation methods that can be implemented to medical images but not all methods are suitable. For the medical purposes, the aims of image segmentation are to study the anatomical structure, identify the region of interest, measure tissue volume to measure growth of tumor and help in treatment planning prior to radiation therapy. In this paper, we present a review method for segmentation purposes using Computed Tomography (CT) images. CT images has their own characteristics that affect the ability to visualize anatomic structures and pathologic features such as blurring of the image and visual noise. The details about the methods, the goodness and the problem incurred in the methods will be defined and explained. It is necessary to know the suitable segmentation method in order to get accurate segmentation. This paper can be a guide to researcher to choose the suitable segmentation method especially in segmenting the images from CT scan

  19. Review methods for image segmentation from computed tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Mamat, Nurwahidah; Rahman, Wan Eny Zarina Wan Abdul; Soh, Shaharuddin Cik [Faculty of Science Computer and Mathematics, Universiti Teknologi Mara Malaysia, 40450 Shah Alam Selangor (Malaysia); Mahmud, Rozi [Faculty of Medicine and Health Sciences, Universiti Putra Malaysia 43400 Serdang Selangor (Malaysia)

    2014-12-04

    Image segmentation is a challenging process in order to get the accuracy of segmentation, automation and robustness especially in medical images. There exist many segmentation methods that can be implemented to medical images but not all methods are suitable. For the medical purposes, the aims of image segmentation are to study the anatomical structure, identify the region of interest, measure tissue volume to measure growth of tumor and help in treatment planning prior to radiation therapy. In this paper, we present a review method for segmentation purposes using Computed Tomography (CT) images. CT images has their own characteristics that affect the ability to visualize anatomic structures and pathologic features such as blurring of the image and visual noise. The details about the methods, the goodness and the problem incurred in the methods will be defined and explained. It is necessary to know the suitable segmentation method in order to get accurate segmentation. This paper can be a guide to researcher to choose the suitable segmentation method especially in segmenting the images from CT scan.

  20. A METHOD FOR SEGMENTING FOOD COLOUR IMAGES

    Directory of Open Access Journals (Sweden)

    Giorgio Peri

    2008-06-01

    Full Text Available In this note, a method for segmenting foods from their backgrounds in colour images is presented. The proposed method has three steps: i determination of the optimal decision plane for the segmentation of an image; ii coarse segmentation of the image; iii morphological operations in order to correct possible errors in the segmented image. The method was implemented in MATLAB and tested on 40 colour images of foodstuff with very different morphological and chromatic characteristics, including meat, baked products, fruit and tubers. The experimental results are presented and the performance of method in the segmentation process is assessed. The method has shown to be both effective and efficient also for colour images with high spatial resolution.

  1. Improved High Dynamic Range Image Reproduction Method

    Directory of Open Access Journals (Sweden)

    András Rövid

    2007-10-01

    Full Text Available High dynamic range (HDR of illumination may cause serious distortions andother problems in viewing and further processing of digital images. This paper describes anew algorithm for HDR image creation based on merging images taken with differentexposure time. There are many fields, in which HDR images can be used advantageously,with the help of them the accuracy, reliability and many other features of the certain imageprocessing methods can be improved.

  2. Image Quality Ranking Method for Microscopy

    OpenAIRE

    Sami Koho; Elnaz Fazeli; Eriksson, John E.; Hänninen, Pekka E.

    2016-01-01

    Automated analysis of microscope images is necessitated by the increased need for high-resolution follow up of events in time. Manually finding the right images to be analyzed, or eliminated from data analysis are common day-to-day problems in microscopy research today, and the constantly growing size of image datasets does not help the matter. We propose a simple method and a software tool for sorting images within a dataset, according to their relative quality. We demonstrate the applicabil...

  3. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  4. Imaging of thyroid tumor angiogenesis with microbubbles targeted to vascular endothelial growth factor receptor type 2 in mice

    International Nuclear Information System (INIS)

    To evaluate whether Contrast Enhanced Ultrasund (CEUS) with microbubbles (MBs) targeted to VEGFR-2 is able to characterize in vivo the VEGFR-2 expression in the tumor vasculature of a mouse model of thyroid cancer (Tg-TRK-T1). Animal protocol was approved by Institutional committee on Laboratory Animal Care. Contrast-enhanced ultrasound imaging with MBs targeted with an anti-VEGFR-2 monoclonal antibody (UCAVEGFR-2) and isotype control antibody (UCAIgG) was performed in 7 mice with thyroid carcinoma, 5 mice with hyperplasia or benign thyroid nodules and 4 mice with normal thyroid. After ultrasonography, the tumor samples were harvested for histological examination and VEGFR-2 expression was tested by immunohistochemistry. Data were reported as median and range. Paired non parametric Wilcoxon’s test and ANOVA of Kruskal-Wallis were used. The correlation between the contrast signal and the VEGFR-2 expression was assessed by the Spearman coefficient. The Video intensity difference (VID) caused by backscatter of the retained UCAVEGFR-2 was significantly higher in mice harboring thyroid tumors compared to mice with normal thyroids (P < 0.01) and to mice harboring benign nodules (P < 0.01). No statistically significant differences of VID were observed in the group of mice carrying benign nodules compared to mice with normal thyroids. Moreover in thyroid tumors VID of retained VEGFR-2-targeted UCA was significantly higher than that of control UCAIgG (P <0.05). Results of immunohistochemical analysis confirmed VEGFR-2 overexpression. The magnitude of the molecular ultrasonographic signal from a VEGFR-2-targeted UCA retained by tissue correlates with VEGFR-2 expression determined by immunohistochemistry (rho 0.793, P=0.0003). We demonstrated that CEUS with UCAVEGFR-2 might be used for in vivo non invasive detection and quantification of VEGFR-2 expression in thyroid cancer in mice, and to differentiate benign from malignant thyroid nodules

  5. Image Quality Ranking Method for Microscopy

    Science.gov (United States)

    Koho, Sami; Fazeli, Elnaz; Eriksson, John E.; Hänninen, Pekka E.

    2016-07-01

    Automated analysis of microscope images is necessitated by the increased need for high-resolution follow up of events in time. Manually finding the right images to be analyzed, or eliminated from data analysis are common day-to-day problems in microscopy research today, and the constantly growing size of image datasets does not help the matter. We propose a simple method and a software tool for sorting images within a dataset, according to their relative quality. We demonstrate the applicability of our method in finding good quality images in a STED microscope sample preparation optimization image dataset. The results are validated by comparisons to subjective opinion scores, as well as five state-of-the-art blind image quality assessment methods. We also show how our method can be applied to eliminate useless out-of-focus images in a High-Content-Screening experiment. We further evaluate the ability of our image quality ranking method to detect out-of-focus images, by extensive simulations, and by comparing its performance against previously published, well-established microscopy autofocus metrics.

  6. Literature Review of Image Denoising Methods

    Institute of Scientific and Technical Information of China (English)

    LIU Qian; YANG Xing-qiang; LI Yun-liang

    2014-01-01

    Image denoising is a fundamental and important task in image processing and computer vision fields. A lot of methods are proposed to reconstruct clean images from their noisy versions. These methods differ in both methodology and performance. On one hand, denoising methods can be classified into local and nonlocal methods. On the other hand, they can be marked as spatial and frequency domain methods. Sparse coding and low-rank are two popular techniques for denoising recently. This paper summarizes existing techniques and provides several promising directions for further studying in the future.

  7. Fuzzy methods and image fusion in a digital image processing

    OpenAIRE

    Jaroslav Vlach; Milan Kolar

    2012-01-01

    Although the basics of image processing were laid more than 50 years ago, significant development occurred mainly in the last 25 years with the entrance of personal computers and today's problems are already very sophisticated and quick. This article is a contribution to the study of the use of fuzzy logic methods and image fusion for image processing using LabVIEW tools for quality management, in this case especially in the jewelry industry.  

  8. Fuzzy Methods and Image Fusion in a Digital Image Processing

    Directory of Open Access Journals (Sweden)

    Jaroslav Vlach

    2012-01-01

    Full Text Available Although the basics of image processing were laid more than 50 years ago, significant development occurred mainly in the last 25 years with the entrance of personal computers and today's problems are already very sophisticated and quick. This article is a contribution to the study of the use of fuzzy logic methods and image fusion for image processing using LabVIEW tools for quality management, in this case especially in the jewelry industry.  

  9. Magnetic resonance spectroscopy as an imaging method

    International Nuclear Information System (INIS)

    An experimental Magnetic Resonance (MR) system with 4 tesla flux density was set up. For that purpose a data acquisition system and RF coils for resonance frequencies up to 170 MHz were developed. Methods for image guided spectroscopy as well as spectroscopic imaging focussing on the nuclei 1H and 13C were developed and tested on volunteers and selected patients. The advantages of the high field strength with respect to spectroscopic studies were demonstrated. Developments of a new fast imaging technique for the acquisition of scout images as well as a method for mapping and displaying the magnetic field inhomogeneity in-vivo represent contributions to the optimisation of the experimental procedure in spectroscopic studies. Investigations on the interaction of RF radiation with the exposed tissue allowed conclusions regarding the applicability of MR methods at high field strengths. Methods for display and processing of multi-dimensional spectroscopic imaging data sets were developed and existing methods for real-time image synthesis were extended. Results achieved in the field of computer aided analysis of MR images comprised new techniques for image background detection, contour detection and automatic image interpretation as well as knowledge bases for textural representation of medical knowledge for diagnosis. (orig.) With 82 refs., 3 tabs., 75 figs

  10. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt; Bak, M; Vach, W; Rose, C

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... had clinical impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  11. The method of infrared polariametric imaging

    Science.gov (United States)

    Zhou, Qiang; Feng, Hua-jun; Xu, Zhi-hai; Li, Qi; Chen, Yue-ting

    2013-09-01

    Due to the low contrast ,lack of details and difficulties to distinguish target from background in traditional infrared(IR) imaging systems, the detection and recognition probability of camouflage infrared target is relatively low. Compared with the traditional IR imaging systems, the method of polarimetric imaging uses polarization information, which can help detect and isolate manmade objects from the natural environment in complex. The method of infrared polarimetric imaging is proposed in this paper. The experiment builds the IR polarimetric imaging system. An IR polarizer made of BaF2 is assembled before the IR camera. By rotating the IR polarizer, twelve polarization images are obtained at every thirty degree. The gray levels of the images are calculated by program. Stokes polarization vector representation is introduced to calculate I of stokes vector and degree of linear polarization (DoLP) with polarization images. According to the character of parameter I of stokes vector and DoLP, we propose an IR polarization fusion method based on Shearlets using regional saliency analysis. This method can highlight the target area and have good performance in the fusion of IR radiation information and IR polarization characteristics. To test the effectiveness of this method, we use mid-wave infrared (MWIR) camera and long-wave infrared(LWIR) camera to get real images. Compared with original image, both the subjective and objective evaluation results indicate that the enhanced images obtained by our method have much more image details and polarization information, which is useful for target detection and recognition.

  12. REGULATION OF VASCULOGENESIS AND ANGIOGENESIS

    Science.gov (United States)

    Regulation of vasculogenesis and angiogenesis.B.D. AbbottReproductive Toxicology Division, Environmental Protection Agency, Research Triangle Park, North Carolina, USA Vasculogenesis and angiogenesis are regulated by a complex, interactive family of receptors and lig...

  13. Swarm Optimization Methods in Microwave Imaging

    Directory of Open Access Journals (Sweden)

    Andrea Randazzo

    2012-01-01

    Full Text Available Swarm intelligence denotes a class of new stochastic algorithms inspired by the collective social behavior of natural entities (e.g., birds, ants, etc.. Such approaches have been proven to be quite effective in several applicative fields, ranging from intelligent routing to image processing. In the last years, they have also been successfully applied in electromagnetics, especially for antenna synthesis, component design, and microwave imaging. In this paper, the application of swarm optimization methods to microwave imaging is discussed, and some recent imaging approaches based on such methods are critically reviewed.

  14. Inhibitors of Angiogenesis.

    Science.gov (United States)

    Büning, H; Hacker, U T

    2016-01-01

    Angiogenesis plays a pivotal role in malignant, ischemic, inflammatory, infectious and immune disorders. The increasing molecular understanding of angiogenic processes fostered the development of strategies to induce or inhibit angiogenesis for therapeutic purposes. Here, we focus on anti-angiogenic therapies, which represent a standard of care in the treatment of different cancer types and in neovascular age-related macular degeneration. Specifically, strategies related to the blockade of angiogenic proteins and receptors will be outlined covering both preclinical and clinical aspects. Finally, examples of gene therapy based anti-angiogenic approaches are presented. PMID:27236560

  15. From angiogenesis to neuropathology

    Science.gov (United States)

    Greenberg, David A.; Jin, Kunlin

    2005-12-01

    Angiogenesis - the growth of new blood vessels - is a crucial force for shaping the nervous system and protecting it from disease. Recent advances have improved our understanding of how the brain and other tissues grow new blood vessels under normal and pathological conditions. Angiogenesis factors, especially vascular endothelial growth factor, are now known to have roles in the birth of new neurons (neurogenesis), the prevention or mitigation of neuronal injury (neuroprotection), and the pathogenesis of stroke, Alzheimer's disease and motor neuron disease. As our understanding of pathophysiology grows, these developments may point the way towards new molecular and cell-based therapies.

  16. Cancer Immunotherapy of Targeting Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    JianmeiHou; LingTian; YuquanWei

    2004-01-01

    Tumor growth and metastasis are angiogenesis-dependent. Anti-angiogenic therapy may be a useful approach to cancer therapy. This review discussed tumor angiogenesis and immunotherapy of targeting tumor angiogenesis from two main aspects: (1) active vaccination to induce effective anti-angiogenesis immunity; (2) passive immunotherapy with anti-pro-angiogenic molecules relevant antibody. Evidence from the recent years suggested that anti-angiogenic therapy should be one of the most promising approaches to cancer therapy.

  17. METHODS FOR SEGMENTATION OF IVUS ATHEROSCLEROSIS IMAGES

    OpenAIRE

    R. Ravindraiah; K. Tejaswini

    2013-01-01

    Segmentation is an important aspect of medical image processing. Segmentation of coronary arteries ofatherosclerosis is one important process prior to many analyses and visualization tasks for intravascular ultrasound (IVUS)images. It is also helpful in the finding of the disease and its progressive treatment. Different methods are used for medicalimage segmentation such as Clustering methods, Thresholding method, Classifier, Region Growing, Deformable Model,Markov Random Model etc. The main ...

  18. Digital image envelope: method and evaluation

    Science.gov (United States)

    Huang, H. K.; Cao, Fei; Zhou, Michael Z.; Mogel, Greg T.; Liu, Brent J.; Zhou, Xiaoqiang

    2003-05-01

    Health data security, characterized in terms of data privacy, authenticity, and integrity, is a vital issue when digital images and other patient information are transmitted through public networks in telehealth applications such as teleradiology. Mandates for ensuring health data security have been extensively discussed (for example The Health Insurance Portability and Accountability Act, HIPAA) and health informatics guidelines (such as the DICOM standard) are beginning to focus on issues of data continue to be published by organizing bodies in healthcare; however, there has not been a systematic method developed to ensure data security in medical imaging Because data privacy and authenticity are often managed primarily with firewall and password protection, we have focused our research and development on data integrity. We have developed a systematic method of ensuring medical image data integrity across public networks using the concept of the digital envelope. When a medical image is generated regardless of the modality, three processes are performed: the image signature is obtained, the DICOM image header is encrypted, and a digital envelope is formed by combining the signature and the encrypted header. The envelope is encrypted and embedded in the original image. This assures the security of both the image and the patient ID. The embedded image is encrypted again and transmitted across the network. The reverse process is performed at the receiving site. The result is two digital signatures, one from the original image before transmission, and second from the image after transmission. If the signatures are identical, there has been no alteration of the image. This paper concentrates in the method and evaluation of the digital image envelope.

  19. Agent Based Image Segmentation Method : A Review

    OpenAIRE

    Pooja Mishra; Navita Srivastava; Shukla, K. K.; Achintya Singlal

    2011-01-01

    Image segmentation is an important research area in computer vision and many segmentation methods have been proposed. This paper attempts to provide a brief overview of elemental segmentation techniques based on boundary or regional approaches. It focuses mainly on the agent based image segmentation techniques

  20. How phototherapy affects angiogenesis

    Science.gov (United States)

    Dyson, Mary

    2007-02-01

    Angiogenesis is essential for normal growth, tissue repair and regeneration. Its stimulation accelerates repair and regeneration including wound healing where these processes are delayed. Its inhibition can reduce the rate of growth of solid tumors. Phototherapy can accelerate the resolution of acute inflammation with the result that the proliferative phase of tissue repair, when angiogenesis occurs, begins earlier than in sham-irradiated controls. Evidence that angiogenesis is enhanced in dermal repair, tendon repair and bone regeneration in rodents is presented. The cellular mechanisms that control angiogenesis involve the interaction of endothelial cells, macrophages, pericytes and other cells in response, for example, to changes in the availability of oxygen in the local environment. Pericytes and macrophages modulate endothelial cell proliferation; pericytes guide endothelial cell migration. The stimulation of endothelial cell proliferation in vitro following exposure to red (660 nm) and infrared (820 nm) radiation, 15 mW, at 2-8 J/cm2 is presented. 1J/cm2 was ineffective. 820 nm irradiation, 15 mW, at 8 J/cm2 was observed to inhibit pericyte proliferation in vitro. Indirect effects on endothelial cell and pericyte proliferation followed stimulation of soluble mediator production by macrophages following exposure to red and infrared radiation. The potential clinical significance of the results obtained is discussed and the necessity of clinical trials emphasized.

  1. Angiogenesis in breast cancer: a comparative study of the observer variability of methods for determining microvessel density

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Rose, C;

    1998-01-01

    biologic variation among patients was the major contributor to the total variation. The Chalkley and MVD methods have been published to provide significant prognostic estimates in breast cancer, but the Chalkley method has less observer variation and may be superior from a methodologic point of view....

  2. Gimbaled multispectral imaging system and method

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kevin H.; Crollett, Seferino; Henson, Tammy D.; Napier, Matthew; Stromberg, Peter G.

    2016-01-26

    A gimbaled multispectral imaging system and method is described herein. In an general embodiment, the gimbaled multispectral imaging system has a cross support that defines a first gimbal axis and a second gimbal axis, wherein the cross support is rotatable about the first gimbal axis. The gimbaled multispectral imaging system comprises a telescope that fixed to an upper end of the cross support, such that rotation of the cross support about the first gimbal axis causes the tilt of the telescope to alter. The gimbaled multispectral imaging system includes optics that facilitate on-gimbal detection of visible light and off-gimbal detection of infrared light.

  3. Angiogenesis: Future of pharmacological modulation

    Directory of Open Access Journals (Sweden)

    Bisht Manisha

    2010-01-01

    Full Text Available Angiogenesis is a fundamental biological process that is regulated by a fine balance between pro- and antiangiogenic molecules, and is deranged in various diseases. Historically, angiogenesis was only implicated in few diseases, such as, cancer, arthritis, and psoriasis. However, in recent years, it has been increasingly evident that excessive, insufficient or abnormal angiogenesis contributes to the pathogenesis of many more disorders. Research in angiogenesis offers a potential to cure a variety of diseases such as Alzheimer′s and AIDS. Modulation of angiogenesis may have an impact on diseases in the twenty-first century similar to that which the discovery of antibiotics had in the twentieth century.

  4. Historic Methods for Capturing Magnetic Field Images

    Science.gov (United States)

    Kwan, Alistair

    2016-01-01

    I investigated two late 19th-century methods for capturing magnetic field images from iron filings for historical insight into the pedagogy of hands-on physics education methods, and to flesh out teaching and learning practicalities tacit in the historical record. Both methods offer opportunities for close sensory engagement in data-collection…

  5. Historic Methods for Capturing Magnetic Field Images

    Science.gov (United States)

    Kwan, Alistair

    2016-03-01

    I investigated two late 19th-century methods for capturing magnetic field images from iron filings for historical insight into the pedagogy of hands-on physics education methods, and to flesh out teaching and learning practicalities tacit in the historical record. Both methods offer opportunities for close sensory engagement in data-collection processes.

  6. Image Deblurring with Krylov Subspace Methods

    DEFF Research Database (Denmark)

    Hansen, Per Christian

    2011-01-01

    Image deblurring, i.e., reconstruction of a sharper image from a blurred and noisy one, involves the solution of a large and very ill-conditioned system of linear equations, and regularization is needed in order to compute a stable solution. Krylov subspace methods are often ideally suited for this...... three Krylov subspace methods CGLS, MINRES, and GMRES. We describe their regularizing properties, and we discuss some computational aspects such as preconditioning and stopping criteria....

  7. Implicitly Weighted Methods in Robust Image Analysis

    OpenAIRE

    Kalina, J. (Jan)

    2012-01-01

    This paper is devoted to highly robust statistical methods with applications to image analysis. The methods of the paper exploit the idea of implicit weighting, which is inspired by the highly robust least weighted squares regression estimator. We use a correlation coefficient based on implicit weighting of individual pixels as a highly robust similarity measure between two images. The reweighted least weighted squares estimator is considered as an alternative regression estimator with a clea...

  8. An image mosaic method based on corner

    Science.gov (United States)

    Jiang, Zetao; Nie, Heting

    2015-08-01

    In view of the shortcomings of the traditional image mosaic, this paper describes a new algorithm for image mosaic based on the Harris corner. Firstly, Harris operator combining the constructed low-pass smoothing filter based on splines function and circular window search is applied to detect the image corner, which allows us to have better localisation performance and effectively avoid the phenomenon of cluster. Secondly, the correlation feature registration is used to find registration pair, remove the false registration using random sampling consensus. Finally use the method of weighted trigonometric combined with interpolation function for image fusion. The experiments show that this method can effectively remove the splicing ghosting and improve the accuracy of image mosaic.

  9. Imaging methods for knee-joint diagnostics

    International Nuclear Information System (INIS)

    Imaging methods are essential tools for orthopedic diagnostics. For examination of knee-joint disorder, X-ray radiography in four planes is a standard task. Special diagnostic methods are available and can be selected according to the case, and sonography is a method very likely to gain significance. In case of suspected fracture, conventional tomography is the method of choice, although arthroscopy is discussed in this context as a primary examination. CT or NMR imaging are indicated for evaluation of tumors near the knee joint, and latest results show that magnetic resonance tomography is useful for examination of the cruciate ligaments or the cartilage, and CT for imaging of the menisci. CT assisted arthrography for sliding path and cartilage analysis already is an established method for diagnostic evaluation of the chondropathia patellae. (orig./MG)

  10. Corona solar blind ultraviolet image detecting method

    Science.gov (United States)

    Yin, Li-min; Tang, Wen-qing; Zhang, Yu

    2009-07-01

    Corona is one of important reasons of electrical energy loss in the electric power. According to incomplete statistics, corona loss electrical energy has achieved two thousands and fifty millions kW.h in our nation every year. Sometimes corona also can have some disturbance to radio and communication. Therefore to discover and examine corona promptly has the extremely vital significance for conserving energy and realizing high quality communication. Ultraviolet image detecting technology is a preferred corona detection method in electric power. It may realize all-weather reliable survey to corona. The solar blind ultraviolet signal discharged by corona is quite weak. Moreover the ultraviolet image quality has been affected seriously by the detection system noise. A corona solar blind ultraviolet image processing method is proposed in this paper. Ultraviolet image has so small target, low contrast image, district characteristic and real-time demand that it is processed by multi-scale ultraviolet morphology filter technology based on mathematics morphology in this paper. Results show that the method can stretch image contrast, enhance target and weaken noise. The algorithm is easy to deal in parallel and it can be realized easily by hardware. It will be accurately demarcated when the condition of device need to be absolutely measured. The paper proposes a kind of mathematics morphology algorithm. Solar blind ultraviolet image will be further processed according to temperature and humidity in order to remove the infection of corona discharge demarcation and solve correct demarcation question when equipment condition need to be absolutely measured.

  11. A content-based image retrieval method for optical colonoscopy images based on image recognition techniques

    Science.gov (United States)

    Nosato, Hirokazu; Sakanashi, Hidenori; Takahashi, Eiichi; Murakawa, Masahiro

    2015-03-01

    This paper proposes a content-based image retrieval method for optical colonoscopy images that can find images similar to ones being diagnosed. Optical colonoscopy is a method of direct observation for colons and rectums to diagnose bowel diseases. It is the most common procedure for screening, surveillance and treatment. However, diagnostic accuracy for intractable inflammatory bowel diseases, such as ulcerative colitis (UC), is highly dependent on the experience and knowledge of the medical doctor, because there is considerable variety in the appearances of colonic mucosa within inflammations with UC. In order to solve this issue, this paper proposes a content-based image retrieval method based on image recognition techniques. The proposed retrieval method can find similar images from a database of images diagnosed as UC, and can potentially furnish the medical records associated with the retrieved images to assist the UC diagnosis. Within the proposed method, color histogram features and higher order local auto-correlation (HLAC) features are adopted to represent the color information and geometrical information of optical colonoscopy images, respectively. Moreover, considering various characteristics of UC colonoscopy images, such as vascular patterns and the roughness of the colonic mucosa, we also propose an image enhancement method to highlight the appearances of colonic mucosa in UC. In an experiment using 161 UC images from 32 patients, we demonstrate that our method improves the accuracy of retrieving similar UC images.

  12. An open-label, multicenter, phase 2a study to assess the feasibility of imaging metastases in late-stage cancer patients with the alpha{sub v}beta{sub 3}-selective angiogenesis imaging agent 99mTc-NC100692

    Energy Technology Data Exchange (ETDEWEB)

    Axelsson, Rimma (Division of Radiology, Dept. of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Inst., Karolinska Univ. Hospital, Stockholm (Sweden)), e-mail: rimma.axelsson@ki.se; Bach-Gansmo, Tore (The Norwegian Radium Hospital, Oslo (Norway)); Castell-Conesa, Juan (Hospital Universitari Vall d' Hebron, Barcelona (Spain)); McParland, Brian J. (Research and Development, Medical Diagnostics, GE Healthcare Ltd., Amersham (United Kingdom))

    2010-01-15

    Background: The alpha{sub v}beta{sub 3} integrin is one of the angiogenesis-related membrane proteins highly expressed on the neovasculature of breast cancer and lung carcinomas. Labeling of the alpha{sub v}beta{sub 3} integrin with 99mTc-NC100692 provides a potential tool for imaging angiogenesis and hence the presence of malignant lesions. Purpose: To determine the feasibility of detecting metastatic lesions in liver, lung, bone, and brain with scintigraphy using the alpha{sub v}beta{sub 3}-avid imaging agent 99mTc-NC100692 in patients with breast or lung cancer, and to assess its safety profile. Material and Methods: Twenty-five patients, 15 with lung cancer and 10 with breast cancer, were recruited at 10 centers. Metastases were newly diagnosed by computed tomography, magnetic resonance imaging, or bone scintigraphy, i.e., the reference standard. Patients underwent whole-body scans of approximately 10-15 min duration beginning at 45 min post-injection and a SPECT acquisition of approximately 30 min beginning at 75 min after injection of up to 1100 MBq 99mTc-NC100692. In case of liver metastases, dynamic acquisitions of 15 min were performed starting immediately post-injection. Safety measurements were performed up to 2.5 hours after injection and included hematology, serum biochemistry, coagulation, urine analysis, vital signs, oximetry, 12-lead ECG assessments, and a physical examination. Results: In patients with breast cancer, 99mTc-NC100692 scintigraphy detected 1 of 7 liver, 4 of 5 lung, 8 of 17 bone, and 1 of 1 brain metastases. The corresponding numbers for lung cancer patients were 0 of 2, 17 of 18, 2 of 2, and 7 of 9. There was overall stability through the follow-up period for all investigated safety parameters. Conclusion: Scintigraphy with 99mTc-NC100692 is feasible for detection of lung and brain metastases from breast and lung cancer, while the detection of liver and bone lesions is poor. The use of 99mTc-NC100692 is safe and well tolerated

  13. An open-label, multicenter, phase 2a study to assess the feasibility of imaging metastases in late-stage cancer patients with the {alpha}{sub v}{beta}{sub 3}-selective angiogenesis imaging agent {sup 99m}Tc-NC100692

    Energy Technology Data Exchange (ETDEWEB)

    Axelsson, Rimma [Division of Radiology, Dept. of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Inst., Karolinska Univ. Hospital, Stockholm (Sweden)], e-mail: rimma.axelsson@ki.se; Bach-Gansmo, Tore [The Norwegian Radium Hospital, Oslo (Norway); Castell-Conesa, Juan [Hospital Universitari Vall d' Hebron, Barcelona (Spain); McParland, Brian J. [Research and Development, Medical Diagnostics, GE Healthcare Ltd., Amersham (United Kingdom)

    2010-01-15

    Background: The {alpha}{sub v}{beta}{sub 3} integrin is one of the angiogenesis-related membrane proteins highly expressed on the neovasculature of breast cancer and lung carcinomas. Labeling of the {alpha}{sub v}{beta}{sub 3} integrin with {sup 99m}Tc-NC100692 provides a potential tool for imaging angiogenesis and hence the presence of malignant lesions. Purpose: To determine the feasibility of detecting metastatic lesions in liver, lung, bone, and brain with scintigraphy using the {alpha}{sub v}{beta}{sub 3}-avid imaging agent {sup 99m}Tc-NC100692 in patients with breast or lung cancer, and to assess its safety profile. Material and Methods: Twenty-five patients, 15 with lung cancer and 10 with breast cancer, were recruited at 10 centers. Metastases were newly diagnosed by computed tomography, magnetic resonance imaging, or bone scintigraphy, i.e., the reference standard. Patients underwent whole-body scans of approximately 10-15 min duration beginning at 45 min post-injection and a SPECT acquisition of approximately 30 min beginning at 75 min after injection of up to 1100 MBq {sup 99m}Tc-NC100692. In case of liver metastases, dynamic acquisitions of 15 min were performed starting immediately post-injection. Safety measurements were performed up to 2.5 hours after injection and included hematology, serum biochemistry, coagulation, urine analysis, vital signs, oximetry, 12-lead ECG assessments, and a physical examination. Results: In patients with breast cancer, {sup 99m}Tc-NC100692 scintigraphy detected 1 of 7 liver, 4 of 5 lung, 8 of 17 bone, and 1 of 1 brain metastases. The corresponding numbers for lung cancer patients were 0 of 2, 17 of 18, 2 of 2, and 7 of 9. There was overall stability through the follow-up period for all investigated safety parameters. Conclusion: Scintigraphy with {sup 99m}Tc-NC100692 is feasible for detection of lung and brain metastases from breast and lung cancer, while the detection of liver and bone lesions is poor. The use of {sup

  14. Image change detection systems, methods, and articles of manufacture

    Science.gov (United States)

    Jones, James L.; Lassahn, Gordon D.; Lancaster, Gregory D.

    2010-01-05

    Aspects of the invention relate to image change detection systems, methods, and articles of manufacture. According to one aspect, a method of identifying differences between a plurality of images is described. The method includes loading a source image and a target image into memory of a computer, constructing source and target edge images from the source and target images to enable processing of multiband images, displaying the source and target images on a display device of the computer, aligning the source and target edge images, switching displaying of the source image and the target image on the display device, to enable identification of differences between the source image and the target image.

  15. Method and apparatus for subtraction image determination

    International Nuclear Information System (INIS)

    The invention relates to a method for X-ray image processing subtracting two images obtained by X-ray radiography and stored in a memory. Using such an apparatus it is for instance possible to picture the blood circulation system of the human body by determining subtraction images of X-ray images before and after injection of contrast media. It has turned out that during the determination and display of the subtraction images on the TV monitor the gray-level fluctuates. The purpose of the invention is to reduce the ill effects of the changes of the X radiation and of the signal transfer in the BV-TV chain. (Auth.)

  16. Handbook of mathematical methods in imaging

    CERN Document Server

    2015-01-01

    The Handbook of Mathematical Methods in Imaging provides a comprehensive treatment of the mathematical techniques used in imaging science. The material is grouped into two central themes, namely, Inverse Problems (Algorithmic Reconstruction) and Signal and Image Processing. Each section within the themes covers applications (modeling), mathematics, numerical methods (using a case example) and open questions. Written by experts in the area, the presentation is mathematically rigorous. This expanded and revised second edition contains updates to existing chapters and 16 additional entries on important mathematical methods such as graph cuts, morphology, discrete geometry, PDEs, conformal methods, to name a few. The entries are cross-referenced for easy navigation through connected topics. Available in both print and electronic forms, the handbook is enhanced by more than 200 illustrations and an extended bibliography. It will benefit students, scientists and researchers in applied mathematics. Engineers and com...

  17. Accelerated gradient methods for constrained image deblurring

    International Nuclear Information System (INIS)

    In this paper we propose a special gradient projection method for the image deblurring problem, in the framework of the maximum likelihood approach. We present the method in a very general form and we give convergence results under standard assumptions. Then we consider the deblurring problem and the generality of the proposed algorithm allows us to add a energy conservation constraint to the maximum likelihood problem. In order to improve the convergence rate, we devise appropriate scaling strategies and steplength updating rules, especially designed for this application. The effectiveness of the method is evaluated by means of a computational study on astronomical images corrupted by Poisson noise. Comparisons with standard methods for image restoration, such as the expectation maximization algorithm, are also reported.

  18. Quantitative statistical methods for image quality assessment.

    Science.gov (United States)

    Dutta, Joyita; Ahn, Sangtae; Li, Quanzheng

    2013-01-01

    Quantitative measures of image quality and reliability are critical for both qualitative interpretation and quantitative analysis of medical images. While, in theory, it is possible to analyze reconstructed images by means of Monte Carlo simulations using a large number of noise realizations, the associated computational burden makes this approach impractical. Additionally, this approach is less meaningful in clinical scenarios, where multiple noise realizations are generally unavailable. The practical alternative is to compute closed-form analytical expressions for image quality measures. The objective of this paper is to review statistical analysis techniques that enable us to compute two key metrics: resolution (determined from the local impulse response) and covariance. The underlying methods include fixed-point approaches, which compute these metrics at a fixed point (the unique and stable solution) independent of the iterative algorithm employed, and iteration-based approaches, which yield results that are dependent on the algorithm, initialization, and number of iterations. We also explore extensions of some of these methods to a range of special contexts, including dynamic and motion-compensated image reconstruction. While most of the discussed techniques were developed for emission tomography, the general methods are extensible to other imaging modalities as well. In addition to enabling image characterization, these analysis techniques allow us to control and enhance imaging system performance. We review practical applications where performance improvement is achieved by applying these ideas to the contexts of both hardware (optimizing scanner design) and image reconstruction (designing regularization functions that produce uniform resolution or maximize task-specific figures of merit). PMID:24312148

  19. Angiogenesis and Multiple Myeloma

    OpenAIRE

    Giuliani, Nicola; Storti, Paola; Bolzoni, Marina; Palma, Benedetta Dalla; Bonomini, Sabrina

    2011-01-01

    The bone marrow microenvironment in multiple myeloma is characterized by an increased microvessel density. The production of pro-angiogenic molecules is increased and the production of angiogenic inhibitors is suppressed, leading to an “angiogenic switch”. Here we present an overview of the role of angiogenesis in multiple myeloma, the pro-angiogenic factors produced by myeloma cells and the microenvironment, and the mechanisms involved in the myeloma-induced angiogenic switch. Current data s...

  20. Circular SAR Optimization Imaging Method of Buildings

    Directory of Open Access Journals (Sweden)

    Wang Jian-feng

    2015-12-01

    Full Text Available The Circular Synthetic Aperture Radar (CSAR can obtain the entire scattering properties of targets because of its great ability of 360° observation. In this study, an optimal orientation of the CSAR imaging algorithm of buildings is proposed by applying a combination of coherent and incoherent processing techniques. FEKO software is used to construct the electromagnetic scattering modes and simulate the radar echo. The FEKO imaging results are compared with the isotropic scattering results. On comparison, the optimal azimuth coherent accumulation angle of CSAR imaging of buildings is obtained. Practically, the scattering directions of buildings are unknown; therefore, we divide the 360° echo of CSAR into many overlapped and few angle echoes corresponding to the sub-aperture and then perform an imaging procedure on each sub-aperture. Sub-aperture imaging results are applied to obtain the all-around image using incoherent fusion techniques. The polarimetry decomposition method is used to decompose the all-around image and further retrieve the edge information of buildings successfully. The proposed method is validated with P-band airborne CSAR data from Sichuan, China.

  1. Contrast-Enhanced Digital Mammography and Angiogenesis

    International Nuclear Information System (INIS)

    Angiogenesis could be a means for pouring contrast media around tumors. In this work, optimization of radiological parameters for contrast-enhanced subtraction techniques in mammography has been performed. A modification of Lemacks' analytical formalism was implemented to model the X-ray absorption in the breast with contrast medium and detection by a digital image receptor. Preliminary results of signal-to-noise ratio analysis show the advantage of subtracting two images taken at different energies, one prior and one posterior to the injection of contrast medium. Preliminary experimental results using a custom-made phantom have shown good agreement with calculations. A proposal is presented for the clinical application of the optimized technique, which aims at finding correlations between angiogenesis indicators and dynamic variables of contrast medium uptake

  2. Skeletonization methods for image and volume inpainting

    OpenAIRE

    Sobiecki, Andre

    2016-01-01

    Image and shape restoration techniques are increasingly important in computer graphics. Many types of restoration techniques have been proposed in the 2D image-processing and according to our knowledge only one to volumetric data. Well-known examples of such techniques include digital inpainting, denoising, and morphological gap filling. However efficient and effective, such methods have several limitations with respect to the shape, size, distribution, and nature of the defects they can find...

  3. Blinds Methods for Detecting Image Fakery

    Czech Academy of Sciences Publication Activity Database

    Saic, Stanislav; Mahdian, Babak

    Piscataway : IEEE, 2008 - (Sanson, L.; Fliegel, K.), s. 280-286 ISBN 978-1-4244-1816-9. [ICCST 2008. IEEE International Carnahan Conference on Security Technology /42./. Prague (CZ), 13.10.2008-16.10.2008] R&D Projects: GA ČR GA102/08/0470 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image forensics * image tampering * Forgery detection * Authentication Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2008/ZOI/saic-blinds methods for detecting image fakery.pdf

  4. Edge Based CNN Image Segmentation Methods for Medical Imaging

    OpenAIRE

    ŢEPELEA Laviniu; GAVRILUŢ Ioan; GACSÁDI Alexandru

    2010-01-01

    This paper presents an analysis of CNN(Cellular Neural Networks) segmentation methods inmedical imaging, based on edge detection. To increasethe efficiency of segmentation, in case of the medicalimages with noise, optimization of CNN templates isproposed. Due to parallel processing, the CNNmethods are considered an advantageous solution forimage processing.

  5. Endostatin derivative angiogenesis inhibitors

    Institute of Scientific and Technical Information of China (English)

    ZHENG Meng-jie

    2009-01-01

    Objective To throw light on the superiority of the anti-angiogenesis activity of endostatin (ES) derivatives by reviewing the recent progress in the field of ES molecular structure modification.Data sources The data used in this article were mainly from PubMed with relevant English articles published from 1971 to May 2008.The search terms were "endostatin" and "angiothesis".Study selection Articles involved in the ES molecular structure modification and the original milestone articles were selected.Results A number of ES derivatives were designed and studied to improve its clinical relevance.The modified ES with polyethylene glycol (PEG),low molecular weight heparin (LMWH) and IgG Fc domain extended the circulation half-life.Meanwhile the recombinant ESs showed more potent anti-tumor activity than native ES in mouse xenografts.Mutated ES also changed its anti-angiogenesis activity.Conclusions The anti-angiogenesis treatment remains a promising tumor therapeutic strategy.New ES derivatives would be a good choice to meet the future challenge on clinical application of ES.

  6. Region-based multisensor image fusion method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Image fusion should consider the priori knowledge of the source images to be fused, such as the characteristics of the images and the goal of image fusion, that is to say, the knowledge about the input data and the application plays a crucial role. This paper is concerned on multiresolution (MR) image fusion. Considering the characteristics of the multisensor (SAR and FLIR etc) and the goal of fusion, which is to achieve one image in possession of the contours feature and the target region feature. It seems more meaningful to combine features rather than pixels. A multisensor image fusion scheme based on K-means cluster and steerable pyramid is presented. K-means cluster is used to segment out objects in FLIR images. The steerable pyramid is a multiresolution analysis method, which has a good property to extract contours information at different scales. Comparisons are made with the relevant existing techniques in the literature. The paper concludes with some examples to illustrate the efficiency of the proposed scheme.

  7. Medical Imaging Image Quality Assessment with Monte Carlo Methods

    Science.gov (United States)

    Michail, C. M.; Karpetas, G. E.; Fountos, G. P.; Kalyvas, N. I.; Martini, Niki; Koukou, Vaia; Valais, I. G.; Kandarakis, I. S.

    2015-09-01

    The aim of the present study was to assess image quality of PET scanners through a thin layer chromatography (TLC) plane source. The source was simulated using a previously validated Monte Carlo model. The model was developed by using the GATE MC package and reconstructed images obtained with the STIR software for tomographic image reconstruction, with cluster computing. The PET scanner simulated in this study was the GE DiscoveryST. A plane source consisted of a TLC plate, was simulated by a layer of silica gel on aluminum (Al) foil substrates, immersed in 18F-FDG bath solution (1MBq). Image quality was assessed in terms of the Modulation Transfer Function (MTF). MTF curves were estimated from transverse reconstructed images of the plane source. Images were reconstructed by the maximum likelihood estimation (MLE)-OSMAPOSL algorithm. OSMAPOSL reconstruction was assessed by using various subsets (3 to 21) and iterations (1 to 20), as well as by using various beta (hyper) parameter values. MTF values were found to increase up to the 12th iteration whereas remain almost constant thereafter. MTF improves by using lower beta values. The simulated PET evaluation method based on the TLC plane source can be also useful in research for the further development of PET and SPECT scanners though GATE simulations.

  8. Infiltrating Mast Cells Correlate with Angiogenesis in Bone Metastases from Gastric Cancer Patients

    Directory of Open Access Journals (Sweden)

    Michele Ammendola

    2015-02-01

    Full Text Available While gastric cancer is a well established angiogenesis driven tumor, no data has been published regarding angiogenesis stimulated by mast cells (MCs positive for tryptase in bone metastases from gastric cancer patients (BMGCP. It is well established that MCs play a role in immune responses and more recently it was demonstrated that MCs have been involved in tumor angiogenesis. We analyzed infiltrating MCs and neovascularization in BMGCP diagnosed by histology. A series of 15 stage T3-4N2-3M1 (by AJCC for Gastric Cancer Staging 7th Edition BMGCP from bone biopsies were selected. Tumour tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of MCs density positive to tryptase (MCDPT, MCs area positive to tryptase (MCAPT, microvascular density (MVD and endothelial area (EA. A significant correlation between MCDPT, MCAPT, MVD and EA groups to each other was found by Pearson and t-test analysis (r ranged from 0.68 to 0.82; p-value ranged from 0.00 to 0.02. Our very preliminary data suggest that infiltrating MCs positive for tryptase may play a role in BMGCP angiogenesis, and could be further evaluated as a novel target of anti-angiogenic therapy.

  9. Five Modulus Method for Image Compression

    Directory of Open Access Journals (Sweden)

    Firas A. Jassim

    2012-11-01

    Full Text Available Data may be compressed by reducing the redundancy in the original data, but this makes the data have more errors. In this paper a novel approach of image compression based on a new method that has been created for image compression which is called Five Modulus Method (FMM. The new method consists of converting each pixel value in an 8×8 block into a multiple of 5 for each of the R, G and B arrays. After that, the new values could be divided by 5 to get new values which are 6-bit length for each pixel and it is less in storage space than the original value which is 8-bits. Also, a new protocol for compression of the new values as a stream of bits has been presented that gives the opportunity to store and transfer the new compressed image easily.

  10. A ROBUST METHOD FOR FINGERPRINTING DIGITAL IMAGES

    Institute of Scientific and Technical Information of China (English)

    Saad Amer; Yi xian Yang

    2001-01-01

    In this paper, a method to fingerprint digital images is proposed, and different watermarked copies with different identification string are made. After determining the number of the customers and the length of the watermark string, this method chooses some values inside the digital image using a characteristic function, and adds watermarks to these values in a way that can protect the product against the attacks happened by comparing two fingerprinted copies.The watermarks are a string of binary numbers -1s and 1s. Every customer will be distinguished by a series of 1s and -1s generated by a pseudo-random generator. The owner of the image can determine the number of customers and the length of the string as well as this method will add another watermarking values to watermark string to protect the product.

  11. Development of Quantification Method for Bioluminescence Imaging

    International Nuclear Information System (INIS)

    Optical molecular luminescence imaging is widely used for detection and imaging of bio-photons emitted by luminescent luciferase activation. The measured photons in this method provide the degree of molecular alteration or cell numbers with the advantage of high signal-to-noise ratio. To extract useful information from the measured results, the analysis based on a proper quantification method is necessary. In this research, we propose a quantification method presenting linear response of measured light signal to measurement time. We detected the luminescence signal by using lab-made optical imaging equipment of animal light imaging system (ALIS) and different two kinds of light sources. One is three bacterial light-emitting sources containing different number of bacteria. The other is three different non-bacterial light sources emitting very weak light. By using the concept of the candela and the flux, we could derive simplified linear quantification formula. After experimentally measuring light intensity, the data was processed with the proposed quantification function. We could obtain linear response of photon counts to measurement time by applying the pre-determined quantification function. The ratio of the re-calculated photon counts and measurement time present a constant value although different light source was applied. The quantification function for linear response could be applicable to the standard quantification process. The proposed method could be used for the exact quantitative analysis in various light imaging equipment with presenting linear response behavior of constant light emitting sources to measurement time

  12. Blind image deconvolution methods and convergence

    CERN Document Server

    Chaudhuri, Subhasis; Rameshan, Renu

    2014-01-01

    Blind deconvolution is a classical image processing problem which has been investigated by a large number of researchers over the last four decades. The purpose of this monograph is not to propose yet another method for blind image restoration. Rather the basic issue of deconvolvability has been explored from a theoretical view point. Some authors claim very good results while quite a few claim that blind restoration does not work. The authors clearly detail when such methods are expected to work and when they will not. In order to avoid the assumptions needed for convergence analysis in the

  13. Platelets actively sequester angiogenesis regulators

    OpenAIRE

    Lakka Klement, Giannoula; Yip, Tai-Tung; Cassiola, Flavia; Kikuchi, Lena; Cervi, David; Podust, Vladimir; Italiano, Joseph E.; Wheatley, Erin; Abou-Slaybi, Abdo; Bender, Elise; Almog, Nava; Kieran, Mark W.; Folkman, Judah

    2009-01-01

    Clinical trials with antiangiogenic agents have not been able to validate plasma or serum levels of angiogenesis regulators as reliable markers of cancer presence or therapeutic response. We recently reported that platelets contain numerous proteins that regulate angiogenesis. We now show that accumulation of angiogenesis regulators in platelets of animals bearing malignant tumors exceeds significantly their concentration in plasma or serum, as well as their levels in platelets from non–tumor...

  14. Image-reconstruction methods in positron tomography

    CERN Document Server

    Townsend, David W; CERN. Geneva

    1993-01-01

    Physics and mathematics for medical imaging\tIn the two decades since the introduction of the X-ray scanner into radiology, medical imaging techniques have become widely established as essential tools in the diagnosis of disease. As a consequence of recent technological and mathematical advances, the non-invasive, three-dimensional imaging of internal organs such as the brain and the heart is now possible, not only for anatomical investigations using X-rays but also for studies which explore the functional status of the body using positron-emitting radioisotopes and nuclear magnetic resonance. Mathematical methods which enable three-dimentional distributions to be reconstructed from projection data acquired by radiation detectors suitably positioned around the patient will be described in detail. The lectures will trace the development of medical imaging from simpleradiographs to the present-day non-invasive measurement of in vivo boichemistry. Powerful techniques to correlate anatomy and function that are cur...

  15. Radiographic imaging method by gas ionisation

    International Nuclear Information System (INIS)

    The search for a substitute of the silver halide film has been intensified worldwide due to the shortage and price increase of silver metal. Gasionography could be an alternative to the wellknown silver film imaging techniques in roentgenology. Therefore the practical basis of the imaging process and the electrophoretic development was investigated. The technical realisation of this method was demonstrated for two different types of X-ray examen by developing a fully automatic chest changer and a mammography system that can be adapted to commercially available imaging stands. The image quality achieved with these apparatus was evaluated in comparison with conventional film techniques in the laboratory as well as in a clinical trial. (orig.)

  16. Parallel imaging methods for phased array MRI

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two parallel methods for magnetic resonance imaging (MRI) using radio frequency (RF) phased array surface coils, named spatial local Fourier encoding (SLFE) and spatial RF encoding (SRFE), are presented. The MR signals are acquired from separate channels across the coils, each of which covers a sub-FOV (field-of-view) in a parallel fashion, and the acquired data are combined to form an image of entire FOV. These two parallel encoding techniques can accelerate MR imaging greatly, yet associated artifact may appear, although the SLFE is an effective image reconstruction method which can reduce the localized artifact in some degrees. By the SRFE, RF coil array can be utilized for spatial encoding through a specialized coil design. The images are acquired in a snapshot with a high signal-to-noise ratio (SNR) without the costly gradient system, resulting in great saving of cost. Both mutual induction and aliasing effect of adjacent coils are critical to the success of SRFE. The strategies of inverse source problem and wavelet transform (WT) can be employed to eliminate them. The results simulated by MATLAB are reported.

  17. Image correlation method for DNA sequence alignment.

    Directory of Open Access Journals (Sweden)

    Millaray Curilem Saldías

    Full Text Available The complexity of searches and the volume of genomic data make sequence alignment one of bioinformatics most active research areas. New alignment approaches have incorporated digital signal processing techniques. Among these, correlation methods are highly sensitive. This paper proposes a novel sequence alignment method based on 2-dimensional images, where each nucleic acid base is represented as a fixed gray intensity pixel. Query and known database sequences are coded to their pixel representation and sequence alignment is handled as object recognition in a scene problem. Query and database become object and scene, respectively. An image correlation process is carried out in order to search for the best match between them. Given that this procedure can be implemented in an optical correlator, the correlation could eventually be accomplished at light speed. This paper shows an initial research stage where results were "digitally" obtained by simulating an optical correlation of DNA sequences represented as images. A total of 303 queries (variable lengths from 50 to 4500 base pairs and 100 scenes represented by 100 x 100 images each (in total, one million base pair database were considered for the image correlation analysis. The results showed that correlations reached very high sensitivity (99.01%, specificity (98.99% and outperformed BLAST when mutation numbers increased. However, digital correlation processes were hundred times slower than BLAST. We are currently starting an initiative to evaluate the correlation speed process of a real experimental optical correlator. By doing this, we expect to fully exploit optical correlation light properties. As the optical correlator works jointly with the computer, digital algorithms should also be optimized. The results presented in this paper are encouraging and support the study of image correlation methods on sequence alignment.

  18. Image segmentation with a finite element method

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    The Mumford-Shah functional for image segmentation is an original approach of the image segmentation problem, based on a minimal energy criterion. Its minimization can be seen as a free discontinuity problem and is based on \\Gamma-convergence and bounded variation functions theories.Some new...... regularization results, make possible to imagine a finite element resolution method.In a first time, the Mumford-Shah functional is introduced and some existing results are quoted. Then, a discrete formulation for the Mumford-Shah problem is proposed and its $\\Gamma$-convergence is proved. Finally, some...

  19. Three-dimensional image signals: processing methods

    Science.gov (United States)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  20. Speckle Suppression Method for SAR Image

    Directory of Open Access Journals (Sweden)

    Jiming Guo

    2013-04-01

    Full Text Available In this study, a new speckle reduction method was proposed in terms of by Bidimensional Empirical Mode Decomposition (BEMD. In this method, the SAR image containing speckle noise was decomposed into a number of elementary components by using BEMD and then the extremal points are done the boundary equivalent extension after screening and the residual continue to be done the boundary equivalent extension until screening is completed, finally, the image was reconstructed, which reduced the speckle noise. Experimental results show that this method has good effect on suppressing speckle noise, compared to the average filter, median filter and gaussian filter and has advantages of sufficiently retaining edge and detail information while suppressing speckle noise.

  1. Radionuclide imaging of perfusion and hypoxia

    International Nuclear Information System (INIS)

    We present a review of radionuclide imaging of tumour vascular physiology as it relates to angiogenesis. We focus on clinical trials in human subjects using PET and SPECT to evaluate tumour physiology, in particular blood flow and hypoxia. A systematic review of literature based on MEDLINE searches updated in February 2010 was performed. Twenty-nine studies were identified for review: 14 dealt with 15O-water PET perfusion imaging, while 8 dealt with 18F-fluoromisonidazole PET hypoxia imaging. Five used SPECT methods. The studies varied widely in technical quality and reporting of methods. A subset of radionuclide methods offers accurate quantitative scientific observations on tumour vascular physiology of relevance to angiogenesis and its treatment. The relationship between cellular processes of angiogenesis and changing physiological function remains poorly defined. The promise of quantitative functional imaging at high specificity and low administered dose sustains interest in radionuclide methods. (orig.)

  2. Tumor Angiogenesis: Insights and Innovations

    Directory of Open Access Journals (Sweden)

    Fernando Nussenbaum

    2010-01-01

    Full Text Available Angiogenesis is a vital process resulting in the formation of new blood vessels. It is normally a highly regulated process that occurs during human development, reproduction, and wound repair. However, angiogenesis can also become a fundamental pathogenic process found in cancer and several other diseases. To date, the inhibition of angiogenesis has been researched at both the bench and the bedside. While several studies have found moderate improvements when treating with angiogenesis inhibitors, greater success is being seen when the inhibition of angiogenesis is combined with other traditional forms of available therapy. This review summarizes several important angiogenic factors, examines new research and ongoing clinical trials for such factors, and attempts to explain how this new knowledge may be applied in the fight against cancer and other angiogenic-related diseases.

  3. Intra-laboratory validation of a human cell based in vitro angiogenesis assay for testing angiogenesis modulators

    OpenAIRE

    TimoYlikomi; JukkaUotila

    2011-01-01

    The developed standardized human cell based in vitro angiogenesis assay was intra-laboratory pre-validated to verify that the method is reliable and relevant for routine testing of modulators of angiogenesis, e.g., pharmaceuticals and industrial chemicals. This assay is based on the earlier published method but it was improved and shown to be more sensitive and rapid than the previous assay. The performance of the assay was assessed by using six reference chemicals, which are widely used phar...

  4. Devices, systems, and methods for imaging

    Science.gov (United States)

    Appleby, David; Fraser, Iain; Watson, Scott

    2008-04-15

    Certain exemplary embodiments comprise a system, which can comprise an imaging plate. The imaging plate can be exposable by an x-ray source. The imaging plate can be configured to be used in digital radiographic imaging. The imaging plate can comprise a phosphor-based image storage device configured to convert an image stored therein into light.

  5. Methods for interventional magnetic resonance imaging

    OpenAIRE

    Vahala, Erkki

    2002-01-01

    This thesis has as its central aim to demonstrate, develop, discuss and promote new methods and technology for improving interventional low field magnetic resonance imaging. The work addresses problems related to accurate localization of minimally invasive surgical tools by describing novel devices and improvements to prior art techniques, such as optical tracking. In addition to instrument guidance, ablative treatment of liver tumours is discussed in connection with low field temperature mea...

  6. Image Analysis by Methods of Dimension Reduction

    Czech Academy of Sciences Publication Activity Database

    Moravec, P.; Snášel, V.; Frolov, A.; Húsek, Dušan; Řezanková, H.; Polyakov, P.Y.

    Los Alamitos: IEEE Computer Society, 2007, s. 272-277. ISBN 0-7695-2894-5. [CISIM'07. International Conference on Computer Information Systems and Industrial Management Applications /6./. Elk (PL), 28.06.2007-30.06.2007] R&D Projects: GA ČR GA201/05/0079 Institutional research plan: CEZ:AV0Z10300504 Keywords : image analysis * methods of dimension reduction * cluster analysis Subject RIV: BB - Applied Statistics, Operational Research

  7. Recent advances in angiogenesis, anti-angiogenesis and vascular targeting.

    Science.gov (United States)

    Bikfalvi, Andreas; Bicknell, Roy

    2002-12-01

    Angiogenesis, the development of new blood vessels, has become a major focus of research. This has been stimulated by the therapeutic opportunities offered by the ability to manipulate the vasculature in pathologies such as cancer. Here, we present an overview of recent advances in angiogenesis. Especially noteworthy is the large volume of information from developmental studies, particularly those that involve transgenic and gene knockout mice. We also discuss the increasing repertoire of drugs with which to manipulate angiogenesis and new endothelial-specific genes with which to target the vasculature. PMID:12457776

  8. In vivo quantitative evaluation of vascular parameters for angiogenesis based on sparse principal component analysis and aggregated boosted trees

    International Nuclear Information System (INIS)

    To solve the multicollinearity issue and unequal contribution of vascular parameters for the quantification of angiogenesis, we developed a quantification evaluation method of vascular parameters for angiogenesis based on in vivo micro-CT imaging of hindlimb ischemic model mice. Taking vascular volume as the ground truth parameter, nine vascular parameters were first assembled into sparse principal components (PCs) to reduce the multicolinearity issue. Aggregated boosted trees (ABTs) were then employed to analyze the importance of vascular parameters for the quantification of angiogenesis via the loadings of sparse PCs. The results demonstrated that vascular volume was mainly characterized by vascular area, vascular junction, connectivity density, segment number and vascular length, which indicated they were the key vascular parameters for the quantification of angiogenesis. The proposed quantitative evaluation method was compared with both the ABTs directly using the nine vascular parameters and Pearson correlation, which were consistent. In contrast to the ABTs directly using the vascular parameters, the proposed method can select all the key vascular parameters simultaneously, because all the key vascular parameters were assembled into the sparse PCs with the highest relative importance. (paper)

  9. Luteal angiogenesis and its control.

    Science.gov (United States)

    Woad, Kathryn J; Robinson, Robert S

    2016-07-01

    Angiogenesis, the formation of new blood vessels from preexisting ones, is critical to luteal structure and function. In addition, it is a complex and tightly regulated process. Not only does rapid and extensive angiogenesis occur to provide the corpus luteum with an unusually high blood flow and support its high metabolic rate, but in the absence of pregnancy, the luteal vasculature must rapidly regress to enable the next cycle of ovarian activity. This review describes a number of key endogenous stimulatory and inhibitory factors, which act in a delicate balance to regulate luteal angiogenesis and ultimately luteal function. In vitro luteal angiogenesis cultures have demonstrated critical roles for fibroblast growth factor 2 (FGF2) in endothelial cell proliferation and sprouting, although other factors such as vascular endothelial growth factor A (VEGFA) and platelet-derived growth factor were important modulators in the control of luteal angiogenesis. Post-transcriptional regulation by small non-coding microRNAs is also likely to play a central role in the regulation of luteal angiogenesis. Appropriate luteal angiogenesis requires the coordinated activity of numerous factors expressed by several cell types at different times, and this review will also describe the role of perivascular pericytes and the importance of vascular maturation and stability. It is hoped that a better understanding of the critical processes underlying the transition from follicle to corpus luteum and subsequent luteal development will benefit the management of luteal function in the future. PMID:27177965

  10. Imaging of gastrinomas by nuclear medicine methods

    International Nuclear Information System (INIS)

    Somatostatin receptor scintigraphy (SRS) is a valuable method for the detection of somatostatin receptor-positive lesions. Most gastrinomas (over-)express the somatostatin receptor subtype 2 which can be targeted by In-111 labeled Octreotide. Different studies show a high sensitivity of SRS for the localization and staging of gastrinomas. SRS seems to be superior to other non-invasive imaging modalities and has been proven to significantly contribute to patient management. However, the sensitivity depends on the size and exact localization of the tumors. Smaller lesions and lesions located in the duodenum show a significantly lower sensitivity. In any case, SRS belongs to the routine imaging procedure for gastrinomas for localization and staging and can also be used for evaluation of the tumor progression. (author)

  11. A nuclear method to authenticate Buddha images

    Science.gov (United States)

    Khaweerat, S.; Ratanatongchai, W.; Channuie, J.; Wonglee, S.; Picha, R.; Promping, J.; Silva, K.; Liamsuwan, T.

    2015-05-01

    The value of Buddha images in Thailand varies dramatically depending on authentication and provenance. In general, people use their individual skills to make the justification which frequently leads to obscurity, deception and illegal activities. Here, we propose two non-destructive techniques of neutron radiography (NR) and neutron activation autoradiography (NAAR) to reveal respectively structural and elemental profiles of small Buddha images. For NR, a thermal neutron flux of 105 n cm-2s-1 was applied. NAAR needed a higher neutron flux of 1012 n cm-2 s-1 to activate the samples. Results from NR and NAAR revealed unique characteristic of the samples. Similarity of the profile played a key role in the classification of the samples. The results provided visual evidence to enhance the reliability of authenticity approval. The method can be further developed for routine practice which impact thousands of customers in Thailand.

  12. Wavelet Imaging Cleaning Method for Atmospheric Cherenkov Telescopes

    OpenAIRE

    Lessard, R. W.; Cayón, L.; Sembroski, G.H.; Gaidos, J. A.

    2001-01-01

    We present a new method of image cleaning for imaging atmospheric Cherenkov telescopes. The method is based on the utilization of wavelets to identify noise pixels in images of gamma-ray and hadronic induced air showers. This method selects more signal pixels with Cherenkov photons than traditional image processing techniques. In addition, the method is equally efficient at rejecting pixels with noise alone. The inclusion of more signal pixels in an image of an air shower allows for a more ac...

  13. A New Fast Reversible Method for Image Safe Transfer

    OpenAIRE

    Puech, William; Rodrigues, José; Develay-Morice, Jean-Eric

    2007-01-01

    International audience In this paper a novel reversible method for fast and safe image transfer is proposed. The method combines compression, data hiding and partial encryption of images in a single processing step. The proposed approach can embed data into the image according to the message size and partially encrypt the image and the message without changing the original image content. Moreover, during the same process the image is lossless compressed. Nevertheless, the compression rate ...

  14. Advanced image-retrieving method for diagnostic image terminal

    International Nuclear Information System (INIS)

    Currently, various image terminals are being considered. However, most do not have the required capabilities for image retrieval for diagnostic use. For the purpose of a diagnosis or a conference by radiologists, the following three basic retrieval functions are indispensable. First is a key-based retrieval that identifies the required images by a key combination. Second is an image-based retrieval. The required image is selected by observing a range of abstract images displayed on the terminal. Third is a similar image retrieval that automatically searches the images having similar diagnostic findings in the database. These functions are developed by integrating relational database technology, image processing techniques, and high-speed similarity detection algorithms

  15. Angiogenesis and Its Therapeutic Opportunities

    Directory of Open Access Journals (Sweden)

    So Young Yoo

    2013-01-01

    Full Text Available Angiogenesis plays critical roles in human physiology that range from reproduction and fetal growth to wound healing and tissue repair. The sophisticated multistep process is tightly regulated in a spatial and temporal manner by “on-off switch signals” between angiogenic factors, extracellular matrix components, and endothelial cells. Uncontrolled angiogenesis may lead to several angiogenic disorders, including vascular insufficiency (myocardial or critical limb ischemia and vascular overgrowth (hemangiomas, vascularized tumors, and retinopathies. Thus, numerous therapeutic opportunities can be envisaged through the successful understanding and subsequent manipulation of angiogenesis. Here, we review the clinical implications of angiogenesis and discuss pro- and antiangiogenic agents that offer potential therapy for cancer and other angiogenic diseases.

  16. Digital Watermarking Method Warranting the Lower Limit of Image Quality of Watermarked Images

    Directory of Open Access Journals (Sweden)

    Iwata Motoi

    2010-01-01

    Full Text Available We propose a digital watermarking method warranting the lower limit of the image quality of watermarked images. The proposed method controls the degradation of a watermarked image by using a lower limit image. The lower limit image means the image of the worst quality that users can permit. The proposed method accepts any lower limit image and does not require it at extraction. Therefore lower limit images can be decided flexibly. In this paper, we introduce 2-dimensional human visual MTF model as an example of obtaining lower limit images. Also we use JPEG-compressed images of quality 75% and 50% as lower limit images. We investigate the performance of the proposed method by experiments. Moreover we compare the proposed method using three types of lower limit images with the existing method in view of the tradeoff between PSNR and the robustness against JPEG compression.

  17. Targeting Angiogenesis for Controlling Neuroblastoma

    OpenAIRE

    Subhasree Roy Choudhury; Surajit Karmakar; Banik, Naren L.; Ray, Swapan K.

    2011-01-01

    Neuroblastoma, a progressive solid tumor in childhood, continues to be a clinical challenge. It is highly vascular, heterogeneous, and extracranial tumor that originates from neural crest. Angiogenesis, genetic abnormalities, and oncogene amplification are mainly responsible for malignant phenotype of this tumor. Survivability of malignant neuroblastoma patients remains poor despite the use of traditional therapeutic strategies. Angiogenesis is a very common and necessary pre-requisite for tu...

  18. Biomedical image understanding methods and applications

    CERN Document Server

    Lim, Joo-Hwee; Xiong, Wei

    2015-01-01

    A comprehensive guide to understanding and interpreting digital images in medical and functional applications Biomedical Image Understanding focuses on image understanding and semantic interpretation, with clear introductions to related concepts, in-depth theoretical analysis, and detailed descriptions of important biomedical applications. It covers image processing, image filtering, enhancement, de-noising, restoration, and reconstruction; image segmentation and feature extraction; registration; clustering, pattern classification, and data fusion. With contributions from ex

  19. Angiogenesis in female reproductive system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Neovascularization, i.e. new blood vessels formation, can be divided into two different processes: vasculogenesis, whereby a primitive vascular network is established during embryogenesis from multipotential mesenchymal progenitors; and angiogenesis, which refers to the new blood vessels formation from pre-existing vessels[1,2]. Angiogenesis contributes to the most process throughout the whole life span from embryonic development to adult growth[2]. In this meaning, neovascularization is usually used to imply angiogenesis. Under physiological condi-tions, angiogenesis is a strictly regulated event and rarely happens in most adult tissues except for fracture or heal-ing of wounds[2,3]. However, a notable phenomenon is that the tissues of ovary and uterine endometrium are unique in the cycle-specific changes in vascularity that occur in each estrous/menstrual cycle. Active angiogenesis occurs in placenta to satisfy the needs of embryonic implantation and development. Defects in angiogenesis are associated with some gynecopathies including luteal phase defect, endometriosis, pregnancy loss and preeclampsia[4].

  20. Methods for processing and imaging marsh foraminifera

    Science.gov (United States)

    Dreher, Chandra A.; Flocks, James G.

    2011-01-01

    This study is part of a larger U.S. Geological Survey (USGS) project to characterize the physical conditions of wetlands in southwestern Louisiana. Within these wetlands, groups of benthic foraminifera-shelled amoeboid protists living near or on the sea floor-can be used as agents to measure land subsidence, relative sea-level rise, and storm impact. In the Mississippi River Delta region, intertidal-marsh foraminiferal assemblages and biofacies were established in studies that pre-date the 1970s, with a very limited number of more recent studies. This fact sheet outlines this project's improved methods, handling, and modified preparations for the use of Scanning Electron Microscope (SEM) imaging of these foraminifera. The objective is to identify marsh foraminifera to the taxonomic species level by using improved processing methods and SEM imaging for morphological characterization in order to evaluate changes in distribution and frequency relative to other environmental variables. The majority of benthic marsh foraminifera consists of agglutinated forms, which can be more delicate than porcelaneous forms. Agglutinated tests (shells) are made of particles such as sand grains or silt and clay material, whereas porcelaneous tests consist of calcite.

  1. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

    OpenAIRE

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

    2013-01-01

    Abstract. Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detecte...

  2. Multitemporal evaluation of topographic correction methods using multispectral synthetic images

    Directory of Open Access Journals (Sweden)

    I. Sola

    2014-06-01

    Full Text Available This paper presents a multitemporal evaluation of topographic correction (TOC methods based on synthetically generated images in order to evaluate the influence of solar angles on the performance of TOC methods. These synthetic images represent the radiance an optical sensor would receive for different periods of the year considering the real topography (SR image, and considering the relief completely horizontal (SH image. The comparison between the corrected image obtained applying a TOC method to a SR image and the SH image of the same area, i.e. considered the ideal correction, allows assessing the performance of each TOC algorithm, quantitatively measured through the Structural Similarity Index (SSIM.

  3. Visualising and quantifying angiogenesis in metastatic colorectal cancer

    DEFF Research Database (Denmark)

    Hansen, Torben Frøstrup; Nielsen, Boye Schnack; Jakobsen, Anders; Sørensen, Flemming Brandt

    2013-01-01

    Angiogenesis plays an important role in tumour growth and dissemination. We have recently shown that blood vessel density, determined by image analysis based on microRNA-126 (miRNA-126) in situ hybridization (ISH) in the primary tumours of metastatic colorectal cancers (mCRC), is predictive of...

  4. Method and apparatus for imaging volume data

    International Nuclear Information System (INIS)

    An imaging system projects a two dimensional representation of three dimensional volumes where surface boundaries and objects internal to the volumes are readily shown, and hidden surfaces and the surface boundaries themselves are accurately rendered by determining volume elements or voxels. An image volume representing a volume object or data structure is written into memory. A color and opacity is assigned to each voxel within the volume and stored as a red (R), green (G), blue (B), and opacity (A) component, three dimensional data volume. The RGBA assignment for each voxel is determined based on the percentage component composition of the materials represented in the volume, and thus, the percentage of color and transparency associated with those materials. The voxels in the RGBA volume are used as mathematical filters such that each successive voxel filter is overlayed over a prior background voxel filter. Through a linear interpolation, a new background filter is determined and generated. The interpolation is successively performed for all voxels up to the front most voxel for the plane of view. The method is repeated until all display voxels are determined for the plane of view. (author)

  5. Review of Road Extraction Methods from SAR Image

    International Nuclear Information System (INIS)

    Road extraction methods from SAR Image are important in the field of SAR image recognition and detection. In the past few decades, scholars at home and abroad have done a lot of experiments and researches. Through the analysis of the current situation, it firstly introduces the road characteristics of SAR image and basic strategies of road extraction. Then, the existing road extraction methods from SAR image are summarized. Finally, the prospective road extraction researches from SAR image are put forward

  6. A quantitation method for mass spectrometry imaging.

    Science.gov (United States)

    Koeniger, Stormy L; Talaty, Nari; Luo, Yanping; Ready, Damien; Voorbach, Martin; Seifert, Terese; Cepa, Steve; Fagerland, Jane A; Bouska, Jennifer; Buck, Wayne; Johnson, Robert W; Spanton, Stephen

    2011-02-28

    A new quantitation method for mass spectrometry imaging (MSI) with matrix-assisted laser desorption/ionization (MALDI) has been developed. In this method, drug concentrations were determined by tissue homogenization of five 10 µm tissue sections adjacent to those analyzed by MSI. Drug levels in tissue extracts were measured by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). The integrated MSI response was correlated to the LC/MS/MS drug concentrations to determine the amount of drug detected per MSI ion count. The study reported here evaluates olanzapine in liver tissue. Tissue samples containing a range of concentrations were created from liver harvested from rats administered a single dose of olanzapine at 0, 1, 4, 8, 16, 30, or 100 mg/kg. The liver samples were then analyzed by MALDI-MSI and LC/MS/MS. The MALDI-MSI and LC/MS/MS correlation was determined for tissue concentrations of ~300 to 60,000 ng/g and yielded a linear relationship over two orders of magnitude (R(2) = 0.9792). From this correlation, a conversion factor of 6.3 ± 0.23 fg/ion count was used to quantitate MSI responses at the pixel level (100 µm). The details of the method, its importance in pharmaceutical analysis, and the considerations necessary when implementing it are presented. PMID:21259359

  7. Subsurface imaging by electrical and EM methods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This report consists of 3 subjects. 1) Three dimensional inversion of resistivity data with topography : In this study, we developed a 3-D inversion method based on the finite element calculation of model responses, which can effectively accommodate the irregular topography. In solving the inverse problem, the iterative least-squares approach comprising the smoothness-constraints was taken along with the reciprocity approach in the calculation of Jacobian. Furthermore the Active Constraint Balancing, which has been recently developed by ourselves to enhance the resolving power of the inverse problem, was also employed. Since our new algorithm accounts for the topography in the inversion step, topography correction is not necessary as a preliminary processing and we can expect a more accurate image of the earth. 2) Electromagnetic responses due to a source in the borehole : The effects of borehole fluid and casing on the borehole EM responses should thoroughly be analyzed since they may affect the resultant image of the earth. In this study, we developed an accurate algorithm for calculating the EM responses containing the effects of borehole fluid and casing when a current-carrying ring is located on the borehole axis. An analytic expression for primary vertical magnetic field along the borehole axis was first formulated and the fast Fourier transform is to be applied to get the EM fields at any location in whole space. 3) High frequency electromagnetic impedance survey : At high frequencies the EM impedance becomes a function of the angle of incidence or the horizontal wavenumber, so the electrical properties cannot be readily extracted without first eliminating the effect of horizontal wavenumber on the impedance. For this purpose, this paper considers two independent methods for accurately determining the horizontal wavenumber, which in turn is used to correct the impedance data. The 'apparent' electrical properties derived from the corrected impedance

  8. An Effective Method of Image Retrieval using Image Mining Techniques

    OpenAIRE

    Kannan, A.; Mohan, V.; N Anbazhagan

    2010-01-01

    The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CBIR)...

  9. An Effective Method of Image Retrieval using Image Mining Techniques

    Directory of Open Access Journals (Sweden)

    A.Kannan

    2010-11-01

    Full Text Available The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CBIR which performs retrieval based on the similarity defined in terms of extracted features with more objectiveness. The drawback in CBIR is the features of the query image alone are considered. Hence, a new technique called Image retrieval based on optimum clusters is proposed for improving user interaction with image retrieval systems by fully exploiting the similarity information. The index is created by describing the images according to their color characteristics, with compact feature vectors, that represent typical color distributions [12].

  10. Methods and systems for producing compounded ultrasound images

    OpenAIRE

    Hansen, Jens Munk; Nikolov, Svetoslav; Kortbek, Jacob; Jensen, Jørgen Arendt

    2012-01-01

    Disclosed is a method for producing compounded ultrasound images by beamforming a first and a second low-resolution image using data from a first ultrasound emission, beamforming a third and a fourth low-resolution image using data from a second ultrasound emission, summing said first and said third low-resolution image creating a first high-resolution image and said second and said fourth low-resolution image creating a second high-resolution image, wherein the method further comprises compu...

  11. A digital image capture method: legal and criminalistic aspects

    OpenAIRE

    Šiurna, Žilvinas

    2007-01-01

    The graduating paper focuses on the digital image capture method in criminalistic and also on its legal regulation and practical resort in the law enforcement institutions‘ investigations of criminal acts. The digital image capture is one of the methods of digital image capture in criminalistic. Its structure contains digital photography and digital video recording. The digital photography is used for strategical and investigative photography. The usage of the digital image capture method inv...

  12. A Method of Coding and Decoding in Underwater Image Transmission

    Institute of Scientific and Technical Information of China (English)

    程恩

    2001-01-01

    A new method of coding and decoding in the system of underwater image transmission is introduced, including the rapid digital frequency synthesizer in multiple frequency shift keying,image data generator, image grayscale decoder with intelligent fuzzy algorithm, image restoration and display on microcomputer.

  13. Diagnosis of arteriosclerosis using noninvasive imaging methods

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate usefulness of X-ray CT, MRI, 2D-echo, and digital subtraction angiography (DSA) in detecting arteriosclerotic changes. Plain and enhanced CT scans were performed on 413 subjects to evaluate aortic sclerosis. CT revealed aortic wall calcification, atheromatous projection of the intima, and thickened aortic walls. These findings appeared frequently with increasing age, and the ratio of atherosclerotic changes to the circumference of the aorta increased in the patients with cerebrovascular disease, coronary heart disease, hypertension, and diabetes. In 179 patients, plain CT and coronary angiography were performed. Sensitivity, specificity, and predictive value for estimating coronary stenosis by CT-detected coronary calcification were 79%, 78%, and 89% respectively. MRI also revealed atherosclerotic changes. In 408 subjects MRI was performed using a spin-echo method. Although atheromatous intimal changes were found in 4.8% of normal subjects, these findings were demonstrated in 46% of the patients with diabetes, in 32% of patients with hypertension, and in 20% of patients with ischemic heart disease. 2D-echo was useful in detecting atheromatous intimal changes in the carotid artery. DSA was also useful for detecting stenosis of the peripheral arteries of median size. In conclusion, these imaging methods can play an important role in diagnosing arteriosclerosis. (author)

  14. Diagnosis of arteriosclerosis using noninvasive imaging methods

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoshiaki; Takasu, Junichiro; Sakakibara, Makoto; Morooka, Nobuhiro; Inagaki, Yoshiaki (Chiba Univ. (Japan). School of Medicine)

    1990-12-01

    The purpose of this study is to evaluate usefulness of X-ray CT, MRI, 2D-echo, and digital subtraction angiography (DSA) in detecting arteriosclerotic changes. Plain and enhanced CT scans were performed on 413 subjects to evaluate aortic sclerosis. CT revealed aortic wall calcification, atheromatous projection of the intima, and thickened aortic walls. These findings appeared frequently with increasing age, and the ratio of atherosclerotic changes to the circumference of the aorta increased in the patients with cerebrovascular disease, coronary heart disease, hypertension, and diabetes. In 179 patients, plain CT and coronary angiography were performed. Sensitivity, specificity, and predictive value for estimating coronary stenosis by CT-detected coronary calcification were 79%, 78%, and 89% respectively. MRI also revealed atherosclerotic changes. In 408 subjects MRI was performed using a spin-echo method. Although atheromatous intimal changes were found in 4.8% of normal subjects, these findings were demonstrated in 46% of the patients with diabetes, in 32% of patients with hypertension, and in 20% of patients with ischemic heart disease. 2D-echo was useful in detecting atheromatous intimal changes in the carotid artery. DSA was also useful for detecting stenosis of the peripheral arteries of median size. In conclusion, these imaging methods can play an important role in diagnosing arteriosclerosis. (author).

  15. Wavelet Transform based Medical Image Fusion With different fusion methods

    Directory of Open Access Journals (Sweden)

    Anjali Patil

    2015-03-01

    Full Text Available This paper proposes wavelet transform based image fusion algorithm, after studying the principles and characteristics of the discrete wavelet transform. Medical image fusion used to derive useful information from multimodality medical images. The idea is to improve the image content by fusing images like computer tomography (CT and magnetic resonance imaging (MRI images, so as to provide more information to the doctor and clinical treatment planning system. This paper based on the wavelet transformation to fused the medical images. The wavelet based fusion algorithms used on medical images CT and MRI, This involve the fusion with MIN , MAX, MEAN method. Also the result is obtained. With more available multimodality medical images in clinical applications, the idea of combining images from different modalities become very important and medical image fusion has emerged as a new promising research field

  16. AN IMAGE RETRIEVAL METHOD BASED ON SPATIAL DISTRIBUTION OF COLOR

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Color histogram is now widely used in image retrieval. Color histogram-based image retrieval methods are simple and efficient but without considering the spatial distribution information of the color. To overcome the shortcoming of conventional color histogram-based image retrieval methods, an image retrieval method based on Radon Transform (RT) is proposed. In order to reduce the computational complexity,wavelet decomposition is used to compress image data. Firstly, images are decomposed by Mallat algorithm.The low-frequency components are then projected by RT to generate the spatial color feature. Finally the moment feature matrices which are saved along with original images are obtained. Experimental results show that the RT based retrieval is more accurate and efficient than traditional color histogram-based method in case that there are obvious objects in images. Further more, RT based retrieval runs significantly faster than the traditional color histogram methods.

  17. Alternate method for to realize image fusion

    International Nuclear Information System (INIS)

    At the present time the image departments have the necessity of carrying out image fusion obtained of diverse apparatuses. Conventionally its fuse resonance or tomography images by X-rays with functional images as the gammagrams and PET images. The fusion technology is for sale with the modern image equipment and not all the cabinets of nuclear medicine have access to it. By this reason we analyze, study and we find a solution so that all the cabinets of nuclear medicine can benefit of the image fusion. The first indispensable requirement is to have a personal computer with capacity to put up image digitizer cards. It is also possible, if one has a gamma camera that can export images in JPG, GIF, TIFF or BMP formats, to do without of the digitizer card and to record the images in a disk to be able to use them in the personal computer. It is required of one of the following commercially available graph design programs: Corel Draw, Photo Shop, FreeHand, Illustrator or Macromedia Flash that are those that we evaluate and that its allow to make the images fusion. Anyone of them works well and a short training is required to be able to manage them. It is necessary a photographic digital camera with a resolution of at least 3.0 mega pixel. The procedure consists on taking photographic images of the radiological studies that the patient already has, selecting those demonstrative images of the pathology in study and that its can also be concordant with the images that we have created in the gammagraphic studies, whether for planar or tomographic. We transfer the images to the personal computer and we read them with the graph design program. To continuation also reads the gammagraphic images. We use those digital tools to make transparent the images, to clip them, to adjust the sizes and to create the fused images. The process is manual and it is requires of ability and experience to choose the images, the cuts, those sizes and the transparency grade. (Author)

  18. Effect of Saffron aqua Extract on Angiogenesis in Chick Chorioalantoic Membrane

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2014-03-01

    Full Text Available Background: Studies confirmed anticancer properties of saffron extract. Angiogenesis, formation of new blood vessels which is necessary in many physiological stages and pathological events such as tumor growth. So it would be an effective strategy to inhibit angiogenesis to treat many cancers and metastasis. In this experimental study, effects of saffron on angiogenesis in chick chorioalantoic membrane (CAM were investigated. Materials and Methods: Fifity ross fertilized eggs divided in 5 groups, including: control, sham exposed, experimental group 1, 2 and 3. In second day of incubation window was opened on eggs. In day 8 gelatin sponges contain gelatin and albumin was put on chorioalantoic membrane and was soaked with Saffron aqua extract in concentration 100, 400 and 800 μg/ml. In 12th day all cases were photographed by photo stereomicroscope. Numbers and lengths of vessels around the sponges were measured by Image J software. Data were analyzed with SPSS-16 in significant level p<0.05. Results: According to data analysis, changes had no correlation on the average length of blood vessels in the first experimental group (41.5±5.5 mm, compared with the control group, (44.5±2.4 mm. While in the second and third experimental group (40.2±2.1 mm and (38.4±3.8 mm these changes were significant (p=0.001. On the other hand, the average number of blood vessels in the first experimental group (22.07±5.2 in compare with the control group (27.46±4.4 shows a significant reduction (p=0.02, this decline between the second (18.80±4.4 and third (15.87±3.8 experimental groups was significant at the level of p=0.001. Conclusion: Saffron extract has a dose dependent inhibitory effect on angiogenesis in chick chorioalantoic membrane.

  19. Differential effect of non-thermal atmospheric-pressure plasma on angiogenesis

    Directory of Open Access Journals (Sweden)

    Beate Haertel

    2014-06-01

    Full Text Available Angiogenesis is a special feature in wound healing and carcinogenesis. For improving wound healing angiogenesis should be promoted, whereas in treating tumors it should be inhibited.Depending on several factors physical non-thermal plasmas can stimulate or inhibit cellular processes and can, thereby, influence angiogenesis. This study focused on effects of plasma on angiogenesis in the chick embryo chorioallantoic membrane (CAM assay and rat aortic ring (AOR test, in which plasma-treated PBS or medium was applied. ImageJ was used to analyze vessel area and branching of vessels of CAM’s. Aortic rings (LEW.1W, WOK.W rats embedded in Matrigel were analyzed by a newly-developed semi-quantitative method to quantify vessel sprouting from aortic rings. In both models spontaneous vessel formation was detected. Vessel area and branching in CAM’s were significantly enhanced by 120-s-plasma-treated PBS compared to untreated controls. This result was comparable with the effect of the growth factor VEGF. No effect of plasma on vessel sprouting from AOR prepared from LEW.1W rats was detected, while it was significantly inhibited in rings of WOK.W rats. Dexamethasone inhibited vessel sprouting from AOR of both rat strains. In conclusion, angiogenic response to plasma was found to be differentially influenced, depending on the models used and on the rat strain in the AOR test. It will now be of importance to learn how plasma has to be designed for either pro- or anti-angiogenic responses.

  20. Relationship between angiogenesis and inflammation in experimental arthritis.

    Science.gov (United States)

    Clavel, Gaelle; Valvason, Chiara; Yamaoka, Kunio; Lemeiter, Delphine; Laroche, Liliane; Boissier, Marie-Christophe; Bessis, Natacha

    2006-09-01

    Background. Angiogenesis is involved in rheumatoid arthritis (RA) leading to leucocyte recruitment and inflammation in the synovium. Furthermore, synovial inflammation itself further potentiates endothelial proliferation and angiogenesis. In this study, we aimed at evaluating the reciprocical relationship between synovial inflammation and angiogenesis in a RA model, namely collagen-induced arthritis (CIA). Methods. CIA was induced by immunization of DBA/1 mice with collagen type II in adjuvant. Endothelial cells were detected using a GSL-1 lectin-specific immunohistochemical staining on knee joint sections. Angiogenesis, clinical scores and histological signs of arthritis were evaluated from the induction of CIA until the end of the experiment. Angiogenesis was quantified by counting both the isolated endothelial cells and vessels stained on each section. To evaluate the effect of increased angiogenesis on CIA, VEGF gene transfer was performed using an adeno-associated virus encoding VEGF (AAV-VEGF), by intra-muscular or intra-articular injection in mice with CIA. Results. We showed an increase in synovial angiogenesis from day 6 to day 55 after CIA induction, and, moreover, joint vascularization and clinical scores of arthritis were correlated (p < 0.0001, r = 0.61). Vascularization and histological scores were also correlated (p = 0.0006, r = 0.51). Systemic VEGF overexpression in mice with CIA was followed by an aggravation of arthritis as compared to AAV-lacZ control group (p < 0.0001). In contrast, there was no difference in clinical scores between control mice and mice injected within the knee with AAV-VEGF, even if joint vascularization was higher in this group than in all other groups (p = 0,05 versus non-injected group). Intra-articular AAV-VEGF injections induced more severe signs of histological inflammation and bone destruction than AAV-Lac Z or no injection. Conclusion. Angiogenesis and joint inflammation evolve in parallel during collagen

  1. 3D Interpolation Method for CT Images of the Lung

    Directory of Open Access Journals (Sweden)

    Noriaki Asada

    2003-06-01

    Full Text Available A 3-D image can be reconstructed from numerous CT images of the lung. The procedure reconstructs a solid from multiple cross section images, which are collected during pulsation of the heart. Thus the motion of the heart is a special factor that must be taken into consideration during reconstruction. The lung exhibits a repeating transformation synchronized to the beating of the heart as an elastic body. There are discontinuities among neighboring CT images due to the beating of the heart, if no special techniques are used in taking CT images. The 3-D heart image is reconstructed from numerous CT images in which both the heart and the lung are taken. Although the outline shape of the reconstructed 3-D heart is quite unnatural, the envelope of the 3-D unnatural heart is fit to the shape of the standard heart. The envelopes of the lung in the CT images are calculated after the section images of the best fitting standard heart are located at the same positions of the CT images. Thus the CT images are geometrically transformed to the optimal CT images fitting best to the standard heart. Since correct transformation of images is required, an Area oriented interpolation method proposed by us is used for interpolation of transformed images. An attempt to reconstruct a 3-D lung image by a series of such operations without discontinuity is shown. Additionally, the same geometrical transformation method to the original projection images is proposed as a more advanced method.

  2. Release of angiogenesis regulatory proteins from platelet alpha granules: modulation of physiologic and pathologic angiogenesis

    OpenAIRE

    Battinelli, Elisabeth M.; Markens, Beth A.; Italiano, Joseph E.

    2011-01-01

    An association between platelets, angiogenesis, and cancer has long been recognized, but the mechanisms linking them remains unclear. Platelets regulate new blood vessel growth through numerous stimulators and inhibitors of angiogenesis by several pathways, including differential exocytosis of angiogenesis regulators. Herein, we investigated the differential release of angiogenesis stimulators and inhibitors from platelets. Activation of human platelets with adenosine diphosphate (ADP) stimul...

  3. Perceptual digital imaging methods and applications

    CERN Document Server

    Lukac, Rastislav

    2012-01-01

    Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition

  4. The role of angiomotin in angiogenesis

    OpenAIRE

    Levchenko, Tanya

    2004-01-01

    Angiogenesis plays key roles during embryonic development, female reproduction and wound repair. Angiogenesis, the formation of new blood vessels from of pre-existing capillaries, is a process tightly regulated by a balance between positive and negative regulators. Unregulated angiogenesis may lead to several angiogenic diseases, and is thought to be crucial for tumor growth and metastasis. The initial recognition of tumor angiogenesis as a therapeutic target began in the 19...

  5. Calibration method by image registration with synthetic image of 3D model

    OpenAIRE

    Tamaki, Toru; Yamamoto, Masanobu

    2003-01-01

    We propose a method for camera calibration based on image registration. This method registers two images; one is a real image captured by a camera with a calibration object with known shape and texture, and the other is a synthetic image containing the object. The proposed method estimates the parameters of the rotation and translation of the object by using the depth imformation of the synthetic image. The Gauss-Newton method is used to minimize the residuals of intensities of the two images...

  6. A new assessment method for image fusion quality

    Science.gov (United States)

    Li, Liu; Jiang, Wanying; Li, Jing; Yuchi, Ming; Ding, Mingyue; Zhang, Xuming

    2013-03-01

    Image fusion quality assessment plays a critically important role in the field of medical imaging. To evaluate image fusion quality effectively, a lot of assessment methods have been proposed. Examples include mutual information (MI), root mean square error (RMSE), and universal image quality index (UIQI). These image fusion assessment methods could not reflect the human visual inspection effectively. To address this problem, we have proposed a novel image fusion assessment method which combines the nonsubsampled contourlet transform (NSCT) with the regional mutual information in this paper. In this proposed method, the source medical images are firstly decomposed into different levels by the NSCT. Then the maximum NSCT coefficients of the decomposed directional images at each level are obtained to compute the regional mutual information (RMI). Finally, multi-channel RMI is computed by the weighted sum of the obtained RMI values at the various levels of NSCT. The advantage of the proposed method lies in the fact that the NSCT can represent image information using multidirections and multi-scales and therefore it conforms to the multi-channel characteristic of human visual system, leading to its outstanding image assessment performance. The experimental results using CT and MRI images demonstrate that the proposed assessment method outperforms such assessment methods as MI and UIQI based measure in evaluating image fusion quality and it can provide consistent results with human visual assessment.

  7. Analysis methods of noise extraction from CT images

    OpenAIRE

    Ioan Gavriluţ; Alexandru Gacsádi; Cristian Grava; Oreste Straciuc; Laviniu Ţepelea

    2009-01-01

    This paper presents a comparativeanalysis of the efficiency of certain filters used forextracting the noise from CT (Computer Tomography)images. Appreciation of filtration methods is based onthe use of mean squared error and direct visualizationof the real medical images.

  8. Multiphase Image Segmentation Using the Deformable Simplicial Complex Method

    DEFF Research Database (Denmark)

    Dahl, Vedrana Andersen; Christiansen, Asger Nyman; Bærentzen, Jakob Andreas

    2014-01-01

    The deformable simplicial complex method is a generic method for tracking deformable interfaces. It provides explicit interface representation, topological adaptivity, and multiphase support. As such, the deformable simplicial complex method can readily be used for representing active contours in...... image segmentation based on deformable models. We show the benefits of using the deformable simplicial complex method for image segmentation by segmenting an image into a known number of segments characterized by distinct mean pixel intensities....

  9. Longitudinal Studies of Angiogenesis in Hormone-Dependent Shionogi Tumors

    Directory of Open Access Journals (Sweden)

    Trevor P. Wade

    2007-07-01

    Full Text Available Vessel size imaging was used to assess changes in the average vessel size of Shionogi tumors throughout the tumor growth cycle. Changes in R2 and R2* relaxivities caused by the injection of a superparamagnetic contrast agent (ferumoxtran-10 were measured using a 2.35-T animal magnetic resonance imaging system, and average vessel size index (VSI was calculated for each stage of tumor progression: growth, regression, and relapse. Statistical analysis using Spearman rank correlation test showed no dependence between vessel size and tumor volume at any stage of the tumor growth cycle. Paired Student's t test was used to assess the statistical significance of the differences in average vessel size for the three stages of the tumor growth cycle. The average VSI for regressing tumors (15.1 ± 6.6 wm was significantly lower than that for growing tumors (35.2 ± 25.5 μm; P < .01. Relapsing tumors also had an average VSI (45.4 ± 41.8 μm higher than that of regressing tumors, although the difference was not statistically significant (P = .067. This study shows that VSI imaging is a viable method for the noninvasive monitoring of angiogenesis during the progression of a Shionogi tumor from androgen dependence to androgen independence.

  10. Comparative analysis of different methods for image enhancement

    Institute of Scientific and Technical Information of China (English)

    吴笑峰; 胡仕刚; 赵瑾; 李志明; 李劲; 唐志军; 席在芳

    2014-01-01

    Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively, it can improve image visual effect. The objective of this work is to implement the image enhancement to gray scale images using different techniques. After the fundamental methods of image enhancement processing are demonstrated, image enhancement algorithms based on space and frequency domains are systematically investigated and compared. The advantage and defect of the above-mentioned algorithms are analyzed. The algorithms of wavelet based image enhancement are also deduced and generalized. Wavelet transform modulus maxima (WTMM) is a method for detecting the fractal dimension of a signal, it is well used for image enhancement. The image techniques are compared by using the mean (μ), standard deviation (s), mean square error (MSE) and PSNR (peak signal to noise ratio). A group of experimental results demonstrate that the image enhancement algorithm based on wavelet transform is effective for image de-noising and enhancement. Wavelet transform modulus maxima method is one of the best methods for image enhancement.

  11. System and method for image mapping and visual attention

    Science.gov (United States)

    Peters, II, Richard A. (Inventor)

    2011-01-01

    A method is described for mapping dense sensory data to a Sensory Ego Sphere (SES). Methods are also described for finding and ranking areas of interest in the images that form a complete visual scene on an SES. Further, attentional processing of image data is best done by performing attentional processing on individual full-size images from the image sequence, mapping each attentional location to the nearest node, and then summing all attentional locations at each node.

  12. ENHANCED GRAPH BASED NORMALIZED CUT METHODS FOR IMAGE SEGMENTATION

    OpenAIRE

    S.D. Kapade; S.M. Khairnar; B.S. Chaudhari

    2014-01-01

    Image segmentation is one of the important steps in digital image processing. Several algorithms are available for segmenting the images, posing many challenges such as precise criteria and efficient computations. Most of the graph based methods used for segmentation depend on local properties of graphs without considering global impressions of image, which ultimately limits segmentation quality. In this paper, we propose an enhanced graph based normalized cut method for extracting global imp...

  13. A comparative study on medical image segmentation methods

    Directory of Open Access Journals (Sweden)

    Praylin Selva Blessy SELVARAJ ASSLEY

    2014-03-01

    Full Text Available Image segmentation plays an important role in medical images. It has been a relevant research area in computer vision and image analysis. Many segmentation algorithms have been proposed for medical images. This paper makes a review on segmentation methods for medical images. In this survey, segmentation methods are divided into five categories: region based, boundary based, model based, hybrid based and atlas based. The five different categories with their principle ideas, advantages and disadvantages in segmenting different medical images are discussed.

  14. An Image Encryption Method Based on Bit Plane Hiding Technology

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; LI Zhitang; TU Hao

    2006-01-01

    A novel image hiding method based on the correlation analysis of bit plane is described in this paper. Firstly, based on the correlation analysis, different bit plane of a secret image is hided in different bit plane of several different open images. And then a new hiding image is acquired by a nesting "Exclusive-OR" operation on those images obtained from the first step. At last, by employing image fusion technique, the final hiding result is achieved. The experimental result shows that the method proposed in this paper is effective.

  15. Methods of fetal MR: beyond T2-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna (Austria)]. E-mail: peter.brugger@meduniwien.ac.at; Stuhr, Fritz [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria); Lindner, Christian [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria); Prayer, Daniela [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

    2006-02-15

    The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body.

  16. Methods of fetal MR: beyond T2-weighted imaging

    International Nuclear Information System (INIS)

    The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body

  17. Experimental and Other Breast Imaging Methods

    Science.gov (United States)

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  18. Medical Image Compression using Wavelet Decomposition for Prediction Method

    Directory of Open Access Journals (Sweden)

    S. M. Ramesh

    2010-01-01

    Full Text Available In this paper offers a simple and lossless compression method for compression of medical images. Method is based on wavelet decomposition of the medical images followed by the correlation analysis of coefficients. The correlation analyses are the basis of prediction equation for each sub band. Predictor variable selection is performed through coefficient graphic method to avoid multicollinearity problem and to achieve high prediction accuracy and compression rate. The method is applied on MRI and CT images. Results show that the proposed approach gives a high compression rate for MRI and CT images comparing with state of the art methods.

  19. Medical Image Compression using Wavelet Decomposition for Prediction Method

    CERN Document Server

    Ramesh, S M

    2010-01-01

    In this paper offers a simple and lossless compression method for compression of medical images. Method is based on wavelet decomposition of the medical images followed by the correlation analysis of coefficients. The correlation analyses are the basis of prediction equation for each sub band. Predictor variable selection is performed through coefficient graphic method to avoid multicollinearity problem and to achieve high prediction accuracy and compression rate. The method is applied on MRI and CT images. Results show that the proposed approach gives a high compression rate for MRI and CT images comparing with state of the art methods.

  20. Some selected quantitative methods of thermal image analysis in Matlab.

    Science.gov (United States)

    Koprowski, Robert

    2016-05-01

    The paper presents a new algorithm based on some selected automatic quantitative methods for analysing thermal images. It shows the practical implementation of these image analysis methods in Matlab. It enables to perform fully automated and reproducible measurements of selected parameters in thermal images. The paper also shows two examples of the use of the proposed image analysis methods for the area of ​​the skin of a human foot and face. The full source code of the developed application is also provided as an attachment. The main window of the program during dynamic analysis of the foot thermal image. PMID:26556680

  1. Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

    Directory of Open Access Journals (Sweden)

    Kuang Tsan Lin

    2014-01-01

    Full Text Available The Rivest-Shamir-Adleman (RSA encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matrix holographic image contain seven groups of codes used for reconstructing the covert image. The seven groups of codes are identification codes, covert-image dimension codes, covert-image graylevel codes, pre-RSA bit number codes, RSA key codes, post-RSA bit number codes, and information codes. The reconstructed covert image derived from the dot-matrix holographic image and the original covert image are exactly the same.

  2. A corrected method of distorted printed circuit board image

    Institute of Scientific and Technical Information of China (English)

    Qiao Nao-Sheng; Ye Yu-Tang; Huang Yong-Lin

    2011-01-01

    This paper proposes a corrected method of distorted image based on adaptive control. First, the adaptive control relationship of pixel point positions between distorted image and its corrected image is given by using polynomial fitting,thus control point pairs between the distorted image and its corrected image are found. Secondly, the value of both image distortion centre and polynomial coefficient is obtained with least square method, thus the relationship of each control point pairs is deduced. In the course of distortion image processing, the gray value of the corrected image is changed into integer with bilinear interpolation. Finally, the experiments are performed to correct two distorted printed circuit board images. The results are perfect and the mean square errors of residual error are tiny.

  3. The Statistical methods of Pixel-Based Image Fusion Techniques

    CERN Document Server

    Al-Wassai, Firouz Abdullah; Al-Zaky, Ali A

    2011-01-01

    There are many image fusion methods that can be used to produce high-resolution mutlispectral images from a high-resolution panchromatic (PAN) image and low-resolution multispectral (MS) of remote sensed images. This paper attempts to undertake the study of image fusion techniques with different Statistical techniques for image fusion as Local Mean Matching (LMM), Local Mean and Variance Matching (LMVM), Regression variable substitution (RVS), Local Correlation Modeling (LCM) and they are compared with one another so as to choose the best technique, that can be applied on multi-resolution satellite images. This paper also devotes to concentrate on the analytical techniques for evaluating the quality of image fusion (F) by using various methods including Standard Deviation (SD), Entropy(En), Correlation Coefficient (CC), Signal-to Noise Ratio (SNR), Normalization Root Mean Square Error (NRMSE) and Deviation Index (DI) to estimate the quality and degree of information improvement of a fused image quantitatively...

  4. 3D Imager and Method for 3D imaging

    NARCIS (Netherlands)

    Kumar, P.; Staszewski, R.; Charbon, E.

    2013-01-01

    3D imager comprising at least one pixel, each pixel comprising a photodetectorfor detecting photon incidence and a time-to-digital converter system configured for referencing said photon incidence to a reference clock, and further comprising a reference clock generator provided for generating the re

  5. A new method for mobile phone image denoising

    Science.gov (United States)

    Jin, Lianghai; Jin, Min; Li, Xiang; Xu, Xiangyang

    2015-12-01

    Images captured by mobile phone cameras via pipeline processing usually contain various kinds of noises, especially granular noise with different shapes and sizes in both luminance and chrominance channels. In chrominance channels, noise is closely related to image brightness. To improve image quality, this paper presents a new method to denoise such mobile phone images. The proposed scheme converts the noisy RGB image to luminance and chrominance images, which are then denoised by a common filtering framework. The common filtering framework processes a noisy pixel by first excluding the neighborhood pixels that significantly deviate from the (vector) median and then utilizing the other neighborhood pixels to restore the current pixel. In the framework, the strength of chrominance image denoising is controlled by image brightness. The experimental results show that the proposed method obviously outperforms some other representative denoising methods in terms of both objective measure and visual evaluation.

  6. Experimental hypoxia and embryonic angiogenesis

    Czech Academy of Sciences Publication Activity Database

    Nanka, O.; Valášek, P.; Dvořáková, Marta; Grim, M.

    2006-01-01

    Roč. 235, č. 3 (2006), s. 723-733. ISSN 1058-8388 Institutional research plan: CEZ:AV0Z50520514 Keywords : Experimental hypoxia * Embryonic angiogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.169, year: 2006

  7. Separation method of heavy-ion particle image from gamma-ray mixed images using an imaging plate

    CERN Document Server

    Yamadera, A; Ohuchi, H; Nakamura, T; Fukumura, A

    1999-01-01

    We have developed a separation method of alpha-ray and gamma-ray images using the imaging plate (IP). The IP from which the first image was read out by an image reader was annealed at 50 deg. C for 2 h in a drying oven and the second image was read out by the image reader. It was found out that an annealing ratio, k, which is defined as a ratio of the photo-stimulated luminescence (PSL) density at the first measurement to that at the second measurement, was different for alpha rays and gamma rays. By subtracting the second image multiplied by a factor of k from the first image, the alpha-ray image was separated from the alpha and gamma-ray mixed images. This method was applied to identify the images of helium, carbon and neon particles of high energies using the heavy-ion medical accelerator, HIMAC. (author)

  8. Novel welding image processing method based on fractal theory

    Institute of Scientific and Technical Information of China (English)

    陈强; 孙振国; 肖勇; 路井荣

    2002-01-01

    Computer vision has come into used in the fields of welding process control and automation. In order to improve precision and rapidity of welding image processing, a novel method based on fractal theory has been put forward in this paper. Compared with traditional methods, the image is preliminarily processed in the macroscopic regions then thoroughly analyzed in the microscopic regions in the new method. With which, an image is divided up to some regions according to the different fractal characters of image edge, and the fuzzy regions including image edges are detected out, then image edges are identified with Sobel operator and curved by LSM (Lease Square Method). Since the data to be processed have been decreased and the noise of image has been reduced, it has been testified through experiments that edges of weld seam or weld pool could be recognized correctly and quickly.

  9. Role of angiogenesis in the pathogenesis of oral lichen planus

    Directory of Open Access Journals (Sweden)

    Nitasha Mittal

    2012-01-01

    Full Text Available Background: The etiology of oral lichen planus (OLP is not fully understood. It is generally considered to be a T-cell mediated chronic inflammatory oral mucosal disease. There is increasing evidence that chronic inflammation is linked to the diseases associated with endothelial dysfunction and is involved in the induction of aberrant angiogenesis. Aim: Our aim was to evaluate the role of angiogenesis in the pathogenesis of OLP by immunohistochemistry, using the CD34 antibody. Materials and Methods: Forty tissue sections (7 of erosive lichen planus, 18 of reticular oral lichen planus, and 15 of normal oral mucosa, were assessed for microvessel density (MVD in five selected areas of high inflammatory infiltrate by immunohistochemistry for the expression of CD34 antibody. Results and Conclusion: The mean MVD was 44.47 in the control group (normal oral mucosa and 97.24 in the OLP group, showing that there is increased angiogenesis in the latter. Reticular OLP had mean MVD of 84.61 and erosive OLP had mean MVD of 129.71, showing relatively greater angiogenesis in erosive OLP as compared to reticular OLP. Thus, angiogenesis can be considered to play a role in both the etiopathogenesis and the progression of OLP.

  10. Quantum dynamic imaging theoretical and numerical methods

    CERN Document Server

    Ivanov, Misha

    2011-01-01

    Studying and using light or "photons" to image and then to control and transmit molecular information is among the most challenging and significant research fields to emerge in recent years. One of the fastest growing areas involves research in the temporal imaging of quantum phenomena, ranging from molecular dynamics in the femto (10-15s) time regime for atomic motion to the atto (10-18s) time scale of electron motion. In fact, the attosecond "revolution" is now recognized as one of the most important recent breakthroughs and innovations in the science of the 21st century. A major participant in the development of ultrafast femto and attosecond temporal imaging of molecular quantum phenomena has been theory and numerical simulation of the nonlinear, non-perturbative response of atoms and molecules to ultrashort laser pulses. Therefore, imaging quantum dynamics is a new frontier of science requiring advanced mathematical approaches for analyzing and solving spatial and temporal multidimensional partial differ...

  11. Dynamic esophagoscintigraphy by a method of condensed imaging

    International Nuclear Information System (INIS)

    Primary evaluation of a method of condensed imaging during processing of the results of dynamic esophagoscintigraphy to detect motor-evacuatory function of the esophagus is presented. Comparison of the results of analysis of dynamic esophagoscintigraphy by a method of condensed imaging and standard methods of diagnostic data processing has shown that a condensed image of the esophagus objectively reflects some passage features of a food lump in the organ

  12. Swarm Optimization Methods in Microwave Imaging

    OpenAIRE

    Andrea Randazzo

    2012-01-01

    Swarm intelligence denotes a class of new stochastic algorithms inspired by the collective social behavior of natural entities (e.g., birds, ants, etc.). Such approaches have been proven to be quite effective in several applicative fields, ranging from intelligent routing to image processing. In the last years, they have also been successfully applied in electromagnetics, especially for antenna synthesis, component design, and microwave imaging. In this paper, the application of swarm optimiz...

  13. Blind Methods for Detecting Image Fakery

    Czech Academy of Sciences Publication Activity Database

    Mahdian, Babak; Saic, Stanislav

    2010-01-01

    Roč. 25, č. 4 (2010), s. 18-24. ISSN 0885-8985 R&D Projects: GA ČR GA102/08/0470 Institutional research plan: CEZ:AV0Z10750506 Keywords : Image forensics * Image Fakery * Forgery detection * Authentication Subject RIV: BD - Theory of Information Impact factor: 0.179, year: 2010 http://library.utia.cas.cz/separaty/2010/ZOI/saic-0343316.pdf

  14. Imperfect twinning - evaluation by imaging methods

    International Nuclear Information System (INIS)

    Conjoined twins are rare malformations and a challenge for both radiologists and pediatric surgeons. Antenatal evaluation is essential for the identification of anatomic fusions and other associated abnormalities, which will enable an adequate surgical planning and the assessment of fetal prognosis. The authors present the clinical and imaging findings of thoracopagus twins, joined by the anterior portion of the thorax, sharing the heart and the liver. Diagnosis was made by ultrasonography and confirmed with fetal magnetic resonance imaging. (author)

  15. Study on Image Quality Improvement Methods for Underwater Imaging Systems

    OpenAIRE

    Lu, Huimin

    2014-01-01

    Underwater survey systems have numerous scientific or industrial applications in the fields of geology, biology, mining, and archeology. These application fields involve various tasks such as ecological studies, environmental damage assessment, and ancient prospection. During two decades, underwater imaging systems are mainly equipped by Underwater Vehicles (UV) for surveying in water or ocean. Challenges associated with obtaining visibility of objects have been difficult to overcome due to t...

  16. A system and method for imaging body areas

    NARCIS (Netherlands)

    Goethals, F.P.C.

    2013-01-01

    The invention relates to a system for imaging one or more external human body areas comprising a photographic device configured to acquire, store and output an image or images of the one or more body areas. The invention also relates to a method for determining a probable disease state of an externa

  17. Training Methods for Image Noise Level Estimation on Wavelet Components

    Directory of Open Access Journals (Sweden)

    A. De Stefano

    2004-12-01

    Full Text Available The estimation of the standard deviation of noise contaminating an image is a fundamental step in wavelet-based noise reduction techniques. The method widely used is based on the mean absolute deviation (MAD. This model-based method assumes specific characteristics of the noise-contaminated image component. Three novel and alternative methods for estimating the noise standard deviation are proposed in this work and compared with the MAD method. Two of these methods rely on a preliminary training stage in order to extract parameters which are then used in the application stage. The sets used for training and testing, 13 and 5 images, respectively, are fully disjoint. The third method assumes specific statistical distributions for image and noise components. Results showed the prevalence of the training-based methods for the images and the range of noise levels considered.

  18. A novel image fusion method using WBCT and PCA

    Institute of Scientific and Technical Information of China (English)

    Qiguang Miao; Baoshu Wang

    2008-01-01

    A novel image fusion algorithm based on wavelet-based contourlet transform (WBCT)and principal component analysis(PCA)is proposed.The PCA method is adopted for the low-frequency components.Using the proposed algorithm to choose the greater of the active measures,the region consistency test is performed for the high-frequency components.Experiments show that the proposed method works better in preserving the edge and texture information than wavelet transform method and Laplacian pyramid (LP)method do in image fusion.Four indicators for the fusion image are given to compare the proposed method with other methods.

  19. Angiogenesis in liver cirrhosis and hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Amarapurkar Anjali

    2008-07-01

    Full Text Available Background: Angiogenesis has been well documented in hepatocellular carcinoma (HCC. As liver cirrhosis is considered preneoplastic condition, the aim of this study was to evaluate the process of angiogenesis using CD 34 as an endothelial cell marker in normal liver, cirrhosis and HCC. Materials and Methods: A total of 111 cases were included in this study, which consisted of 30 cases each of normal liver and cirrhosis that were all autopsy cases. Twenty-one cases of HCC included 10 autopsy specimens, nine surgically resected specimens and two liver biopsies. Remaining were 30 cases of metastasis to the liver, which included 20 autopsy specimens, one surgically resected specimen and nine liver biopsies. The patients were between the age range from 17 to 80 years with 70 males and 11 females. Paraffin-embedded liver sections of all these cases were stained routinely by hematoxylin-eosin stain, while immunohistochemistry for CD 34 was performed for expression of endothelial cells. The positivity of CD 34 staining was evaluated by counting in 10 high-power field, grading was done from 0 to 4 and compared between normal liver, cirrhosis and HCC and metastasis. Results: CD 34 was positive in 16/30 (53.3% cases of cirrhosis, 18/21 (85% cases of HCC and 26 (86.6% of metastasis to the liver. None of the normal liver showed any positivity. Grade 3 to 4 positivity was seen in 4/16 (25% and 13/18 (72% cases of cirrhosis and HCC, respectively. Amongst these, 10 were moderately differentiated, one well differentiated and rest two were fibrolamellar and sarcomatoid variants of HCC. Conclusion: Over expression of endothelial cell marker CD 34 with gradual progression was found from normal liver to cirrhosis to HCC and metastasis. Understanding of this process of angiogenesis might help in the design of efficient and safe antiangiogenic therapy for these liver disorders.

  20. Image analysis methods for gamma-hadron separation

    International Nuclear Information System (INIS)

    Gamma-hadron separation is essential in VHE gamma-ray astronomy. In order to separate gamma-ray- from proton-induced air shower images obtained with the H.E.S.S. imaging atmospheric Cherenkov telescopes, image analysis methods are applied to these camera images. Different classifiers are evaluated in a multivariate analysis framework to test the combined separation power and to check for correlations. The results are presented here.

  1. Bone marrow-derived cells are differentially involved in pathological and physiological retinal angiogenesis in mice

    International Nuclear Information System (INIS)

    Purpose: Bone marrow-derived cells have been shown to play roles in angiogenesis. Although these cells have been shown to promote angiogenesis, it is not yet clear whether these cells affect all types of angiogenesis. This study investigated the involvement of bone marrow-derived cells in pathological and physiological angiogenesis in the murine retina. Materials and methods: The oxygen-induced retinopathy (OIR) model was used as a retinal angiogenesis model in newborn mice. To block the influence of bone marrow-derived cells, the mice were irradiated with a 4-Gy dose of radiation from a 137Cs source. Irradiation was performed in four different conditions with radio dense 2-cm thick lead disks; (1) H group, the head were covered with these discs to protect the eyes from radiation; (2) A group, all of the body was covered with these discs; (3) N group, mice were completely unshielded; (4) C group, mice were put in the irradiator but were not irradiated. On P17, the retinal areas showing pathological and physiological retinal angiogenesis were measured and compared to the retinas of nonirradiated mice. Results: Although irradiation induced leukocyte depletion, it did not affect the number of other cell types or body weight. Retinal nonperfusion areas were significantly larger in irradiated mice than in control mice (P < 0.05), indicating that physiological angiogenesis was impaired. However, the formation of tuft-like angiogenesis processes was more prominent in the irradiated mice (P < 0.05), indicating that pathological angiogenesis was intact. Conclusions: Bone marrow-derived cells seem to be differentially involved in the formation of physiological and pathological retinal vessels. Pathological angiogenesis in the murine retina does not require functional bone marrow-derived cells, but these cells are important for the formation of physiological vessels. Our results add a new insight into the pathology of retinal angiogenesis and bolster the hypothesis that bone

  2. A method for fast automated microscope image stitching.

    Science.gov (United States)

    Yang, Fan; Deng, Zhen-Sheng; Fan, Qiu-Hong

    2013-05-01

    Image stitching is an important technology to produce a panorama or larger image by combining several images with overlapped areas. In many biomedical researches, image stitching is highly desirable to acquire a panoramic image which represents large areas of certain structures or whole sections, while retaining microscopic resolution. In this study, we develop a fast normal light microscope image stitching algorithm based on feature extraction. At first, an algorithm of scale-space reconstruction of speeded-up robust features (SURF) was proposed to extract features from the images to be stitched with a short time and higher repeatability. Then, the histogram equalization (HE) method was employed to preprocess the images to enhance their contrast for extracting more features. Thirdly, the rough overlapping zones of the images preprocessed were calculated by phase correlation, and the improved SURF was used to extract the image features in the rough overlapping areas. Fourthly, the features were corresponded by matching algorithm and the transformation parameters were estimated, then the images were blended seamlessly. Finally, this procedure was applied to stitch normal light microscope images to verify its validity. Our experimental results demonstrate that the improved SURF algorithm is very robust to viewpoint, illumination, blur, rotation and zoom of the images and our method is able to stitch microscope images automatically with high precision and high speed. Also, the method proposed in this paper is applicable to registration and stitching of common images as well as stitching the microscope images in the field of virtual microscope for the purpose of observing, exchanging, saving, and establishing a database of microscope images. PMID:23465523

  3. Fetal magnetic resonance imaging: methods and techniques

    International Nuclear Information System (INIS)

    Since the introduction of fetal magnetic resonance imaging (MRI) into prenatal diagnostics, advances in coil technology and development of ultrafast sequences have further enhanced this technique. At present numerous sequences are available to visualize the whole fetus with high resolution and image quality, even in late stages of pregnancy. Taking into consideration the special circumstances of examination and adjusting sequence parameters to gestational age, fetal anatomy can be accurately depicted. The variety of sequences also allows further characterization of fetal tissues and pathologies. Fetal MRI not only supplies additional information to routine ultrasound studies, but also reveals fetal morphology and pathology in a way hitherto not possible. (orig.)

  4. Warped document image correction method based on heterogeneous registration strategies

    Science.gov (United States)

    Tong, Lijing; Zhan, Guoliang; Peng, Quanyao; Li, Yang; Li, Yifan

    2013-03-01

    With the popularity of digital camera and the application requirement of digitalized document images, using digital cameras to digitalize document images has become an irresistible trend. However, the warping of the document surface impacts on the quality of the Optical Character Recognition (OCR) system seriously. To improve the warped document image's vision quality and the OCR rate, this paper proposed a warped document image correction method based on heterogeneous registration strategies. This method mosaics two warped images of the same document from different viewpoints. Firstly, two feature points are selected from one image. Then the two feature points are registered in the other image base on heterogeneous registration strategies. At last, image mosaics are done for the two images, and the best mosaiced image is selected by OCR recognition results. As a result, for the best mosaiced image, the distortions are mostly removed and the OCR results are improved markedly. Experimental results show that the proposed method can resolve the issue of warped document image correction more effectively.

  5. Prognostic implication of apoptosis and angiogenesis in cervical uteri cancer

    International Nuclear Information System (INIS)

    Purpose: A retrospective study was performed to investigate the relationship between spontaneous apoptosis and angiogenesis uterine cervix squamous cell carcinoma patients. The prognostic value of each (and both) of these biologic parameters was also tested. Methods and Materials: The pathologic materials of 40 cervical uteri squamous cell carcinoma patients were examined and immunohistochemically stained to determine the tumor angiogenesis (tumor microvascular score), using factor VIII-related antigen, and their tumor apoptotic index (AI), using the TdT-mediated dUTP nick end-labeling (TUNEL) method. Three patients were Stage I, 18 were Stage II, 15 were Stage III, and 4 were Stage IV (FIGO classification). All patients were treated with radical radiotherapy and all had follow-up for more than 2 years. Results: The mean AI was 15.1 ± 12.8, with a median of 8.3. The mean tumor microvascular score was 3 9.7 ± 14.4, with a median of 3 8. The patients' age and tumor grade did not seem to significantly affect the prognosis. On the other hand, AI and angiogenesis (tumor microvascular score) were of high prognostic significance. The 3-year disease-free survival (DFS) rate for the patients having AI above the median was 78% (confidence interval [CI] 69-87%), compared to 32% (CI 22-42%) for those having AI below the median. The DFS was 18% (CI 9-27%) for patients having an angiogenesis score above the median, while it was 86% (CI 78-94%) for those patients having a score below the median. Conclusion: Determination of both tumor microvascular score and AI can identify patients with the best prognosis of 100% DFS (with low angiogenesis score and high AI). Women with a high score and low AI had the worst prognosis (DFS = 3%, CI 1-5%). Moreover, high AI can compensate partially for the aggressive behavior of tumors showing a high rate of angiogenesis.

  6. Imaging systems and methods for obtaining and using biometric information

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Kennedy, Mike O [Richland, WA

    2010-11-30

    Disclosed herein are exemplary embodiments of imaging systems and methods of using such systems. In one exemplary embodiment, one or more direct images of the body of a clothed subject are received, and a motion signature is determined from the one or more images. In this embodiment, the one or more images show movement of the body of the subject over time, and the motion signature is associated with the movement of the subject's body. In certain implementations, the subject can be identified based at least in part on the motion signature. Imaging systems for performing any of the disclosed methods are also disclosed herein. Furthermore, the disclosed imaging, rendering, and analysis methods can be implemented, at least in part, as one or more computer-readable media comprising computer-executable instructions for causing a computer to perform the respective methods.

  7. Blind Image Seperation Using Forward Difference Method (FDM

    Directory of Open Access Journals (Sweden)

    Jyothirmayi M

    2011-12-01

    Full Text Available In this paper, blind image separation is performed, exploiting the property of sparseness to representimages. A new sparse representation called forward difference method is proposed. It is known that most ofthe independent component analysis (ICA basis functions, extracted from images are sparse and givesunreliable sparseness measure. In the proposed method, the image mixture is first transformed to sparseimages. These images are divided into blocks and for each block the sparseness measure 0 norm isapplied. The block having the most sparseness is considered to determine the separation matrix. Theefficiency of the proposed method is compared with other sparse representation functions.

  8. 2D geometric measurement method based on industrial CT images

    International Nuclear Information System (INIS)

    To achieve the non-destructive measurement of the internal structure of the objects, a kind of automatic dimension measuring method using industrial computed tomography (ICT) images was presented based on a threshold of edge extraction. First, a pretreatment of CT images was carried out Then, the best threshold segmentation method was used to extract edge, based on this work the automatic geometry measurement of the CT images was achieved. The results show that geometric measurement of images reaches to a certain degree of accuracy and meet the basic needs of accuracy and repeatability. Simultaneously this method may reduce the influence of artifacts. (authors)

  9. An automatic segmentation method for fast imaging in PET

    International Nuclear Information System (INIS)

    A new segmentation method has been developed for PET fast imaging. The technique automatically segments the transmission images into different anatomical regions, it efficiently reduced the PET transmission scan time. The result shows that this method gives only 3 min-scan time which is perfect for attenuation correction of the PET images instead of the original 15-30 min-scan time. This approach has been successfully tested both on phantom and clinical data

  10. Simultaneous multi-headed imager geometry calibration method

    Science.gov (United States)

    Tran, Vi-Hoa; Meikle, Steven Richard; Smith, Mark Frederick

    2008-02-19

    A method for calibrating multi-headed high sensitivity and high spatial resolution dynamic imaging systems, especially those useful in the acquisition of tomographic images of small animals. The method of the present invention comprises: simultaneously calibrating two or more detectors to the same coordinate system; and functionally correcting for unwanted detector movement due to gantry flexing.

  11. Toward a Novel Strategy for Magnetic–Resonance Molecular Imaging and Therapy of Tumor Angiogenesis: Nickel Superparamagnetic Nanoparticles Incorporated into Radiation-Functionalized Polymer Nano-Carriers

    International Nuclear Information System (INIS)

    The more recent research activity of the Irradiated Polymers team focused mainly on nanostructures membranes for nanofiltration and nanofluidic systems in biomedical and energy fields. The so called track-etched membranes were made by chemical revealing of tracks induced from swift heavy ions irradiations in collaboration with the CIRIL laboratory (GANIL, France). The background experience of the tem about electron-polymer interaction allowed us to predict the behavior of the radio-induced grafting, namely radografting, inside ion-tracks. It was the necessary to adapt our detection tools to chemical modification of picomole range and to nanometer scale architecture of these membranes. Consequently, we resorted to the use of high-cost techniques such as small angle neutron scattering to be able to characterize accurately polymer membrane nanopores. In parallel, more accessible techniques like gas permeation have been developed for a rapid evaluation of nanopore radii. The labeling of introduced chemical functionalities with fluorescent probes was a very effective mean to visualize very few amounts of molecules by confocal microscopy and to localize, for the first time, the radiografting inside theetched tracks. The study of such nanostructures has enlarged our perspectives and collaborations. Indeed, it pushed us to electrodeposite metallic nanowires and to create conductive polymer nanotubes to study the conduction in nanochannels of such systems (Biosensors and optoelectronic applications) and to study the ionic conduction in nano-channels filled of hydrogen (Polymer Electrolyte Membrane Fuel Cell application). More recently, since January 2007, we are developing a subject on another kind of polylmer device on which we are applying our known-how in radiografting. It is about the functionalized fluoropolymer nanoparticles for medical imaging. In the following, I describe in more details some of the recent works being carried out at our laboratory on the irradiated

  12. In Vitro and In Vivo Imaging of Prostate Cancer Angiogenesis Using Anti-Vascular Endothelial Growth Factor Receptor 2 Antibody-Conjugated Quantum Dot

    OpenAIRE

    Kwon, Haejin; Lee, Jiyeon; Song, Rita; Hwang, Sung Il; Lee, Junghan; Kim, Young-Hwa; Lee, Hak Jong

    2012-01-01

    Objective Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. Materials and Methods Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with ant...

  13. An automated and simple method for brain MR image extraction

    OpenAIRE

    Zhu Zixin; Liu Jiafeng; Zhang Haiyan; Li Haiyun

    2011-01-01

    Abstract Background The extraction of brain tissue from magnetic resonance head images, is an important image processing step for the analyses of neuroimage data. The authors have developed an automated and simple brain extraction method using an improved geometric active contour model. Methods The method uses an improved geometric active contour model which can not only solve the boundary leakage problem but also is less sensitive to intensity inhomogeneity. The method defines the initial fu...

  14. The method of infrared image simulation based on the measured image

    Science.gov (United States)

    Lou, Shuli; Liu, Liang; Ren, Jiancun

    2015-10-01

    The development of infrared imaging guidance technology has promoted the research of infrared imaging simulation technology and the key of infrared imaging simulation is the generation of IR image. The generation of IR image is worthful in military and economy. In order to solve the problem of credibility and economy of infrared scene generation, a method of infrared scene generation based on the measured image is proposed. Through researching on optical properties of ship-target and sea background, ship-target images with various gestures are extracted from recorded images based on digital image processing technology. The ship-target image is zoomed in and out to simulate the relative motion between the viewpoint and the target according to field of view and the distance between the target and the sensor. The gray scale of ship-target image is adjusted to simulate the radiation change of the ship-target according to the distance between the viewpoint and the target and the atmospheric transmission. Frames of recorded infrared images without target are interpolated to simulate high frame rate of missile. Processed ship-target images and sea-background infrared images are synthetized to obtain infrared scenes according to different viewpoints. Experiments proved that this method is flexible and applicable, and the fidelity and the reliability of synthesis infrared images can be guaranteed.

  15. Acute cutaneous wounds treated with human decellularised dermis show enhanced angiogenesis during healing.

    Directory of Open Access Journals (Sweden)

    Nicholas S Greaves

    Full Text Available BACKGROUND: The influence of skin substitutes upon angiogenesis during wound healing is unclear. OBJECTIVES: To compare the angiogenic response in acute cutaneous human wounds treated with autogenic, allogenic and xenogenic skin substitutes to those left to heal by secondary intention. METHODS: On day 0, four 5mm full-thickness punch biopsies were harvested from fifty healthy volunteers (sites 1-4. In all cases, site 1 healed by secondary intention (control, site 2 was treated with collagen-GAG scaffold (CG, cadaveric decellularised dermis (DCD was applied to site 3, whilst excised tissue was re-inserted into site 4 (autograft. Depending on study group allocation, healing tissue from sites 1-4 was excised on day 7, 14, 21 or 28. All specimens were bisected, with half used in histological and immunohistochemical evaluation whilst extracted RNA from the remainder enabled whole genome microarrays and qRT-PCR of highlighted angiogenesis-related genes. All wounds were serially imaged over 6 weeks using laser-doppler imaging and spectrophotometric intracutaneous analysis. RESULTS: Inherent structural differences between skin substitutes influenced the distribution and organisation of capillary networks within regenerating dermis. Haemoglobin flux (p = 0.0035, oxyhaemoglobin concentration (p = 0.0005, and vessel number derived from CD31-based immunohistochemistry (p = 0.046 were significantly greater in DCD wounds at later time points. This correlated with time-matched increases in mRNA expression of membrane-type 6 matrix metalloproteinase (MT6-MMP (p = 0.021 and prokineticin 2 (PROK2 (p = 0.004. CONCLUSION: Corroborating evidence from invasive and non-invasive modalities demonstrated that treatment with DCD resulted in increased angiogenesis after wounding. Significantly elevated mRNA expression of pro-angiogenic PROK2 and extracellular matrix protease MT6-MMP seen only in the DCD group may contribute to observed responses.

  16. A method to estimate optical distortion using planetary images

    Science.gov (United States)

    Kouyama, Toru; Yamazaki, Atsushi; Yamada, Manabu; Imamura, Takeshi

    2013-09-01

    We developed a method to calibrate optical distortion parameters for axisymmetrical optical systems using images of a spherical target taken at a variety of distances. The method utilizes the fact that the influence of distortion on the apparent radius in the image changes with the disk size of the projected body. Because several planets can be used as the spherical target, this method enables us to obtain distortion parameters in space and by using a large number of planetary images, desired accuracy of parameters can be achieved statistically. The applicability of the method was tested by applying it to simulated planetary images and real Venus images taken by Venus Monitoring Camera onboard the ESA's Venus Express, and optical distortion was successfully retrieved with the pixel position error of less than 1 pixel. Venus is the planet most suitable for the proposed method because of its smooth, nearly spherical surface of the haze layer covering the planet.

  17. ENHANCED GRAPH BASED NORMALIZED CUT METHODS FOR IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    S.D. Kapade

    2014-11-01

    Full Text Available Image segmentation is one of the important steps in digital image processing. Several algorithms are available for segmenting the images, posing many challenges such as precise criteria and efficient computations. Most of the graph based methods used for segmentation depend on local properties of graphs without considering global impressions of image, which ultimately limits segmentation quality. In this paper, we propose an enhanced graph based normalized cut method for extracting global impression and consistencies in the image. We propose a technique to add flexibility to original recursive normalized two way cut method which was further extended to other graph based methods. The results show that the proposed technique improves segmentation quality as well as requires lesser computational time than the regular normalized cut method.

  18. Angiogenesis in tissue engineering: from concept to the vascularization of scaffold construct

    International Nuclear Information System (INIS)

    Angiogenesis, the formation of micro-vascular network from the preexisting vascular vessels, has been studied in the connection to the normal developmental process as well as numerous diseases. In tissue engineering research, angiogenesis is also essential to promote micro-vascular network inside engineered tissue constructs, mimicking a functional blood vessel in vivo. Micro-vascular network can be used to maintain adequate tissue oxygenation, nutrient transfer and waste removal. One of the problems faced by angiogenesis researchers is to find suitable in vitro assays and methods for assessing the effect of regulators on angiogenesis and micro-vessel formation. The assay would be reliable and repeatable with easily quantifiable with physiologically relevant. This review aims to highlights recent advanced and future challenges in developing and using an in vitro angiogenesis assay for the application on biomedical and tissue engineering research

  19. Angiogenesis in tissue engineering: from concept to the vascularization of scaffold construct

    Science.gov (United States)

    Amirah Ishak, Siti; Pangestu Djuansjah, J. R.; Kadir, M. R. Abdul; Sukmana, Irza

    2014-06-01

    Angiogenesis, the formation of micro-vascular network from the preexisting vascular vessels, has been studied in the connection to the normal developmental process as well as numerous diseases. In tissue engineering research, angiogenesis is also essential to promote micro-vascular network inside engineered tissue constructs, mimicking a functional blood vessel in vivo. Micro-vascular network can be used to maintain adequate tissue oxygenation, nutrient transfer and waste removal. One of the problems faced by angiogenesis researchers is to find suitable in vitro assays and methods for assessing the effect of regulators on angiogenesis and micro-vessel formation. The assay would be reliable and repeatable with easily quantifiable with physiologically relevant. This review aims to highlights recent advanced and future challenges in developing and using an in vitro angiogenesis assay for the application on biomedical and tissue engineering research.

  20. Imaging method for interface rheological characterization

    CERN Document Server

    Chebel, Nicolas Abi; Risso, Frédéric; Guiraud, Pascal; Ravelet, Florent; Dalmazzone, Christine; Noïk, Christine

    2008-01-01

    The present work investigates free damped oscillations of an oil drop in water after its release from a capillary tube. Both pure heptane drops and diluted crude oil drops are considered (in the second case the interface is covered by amphiphilic species, natural components of crude oil). Shadowgraph images of the drops are taken by means of a high speed camera and the drop contour is detected by image processing. The axisymmetric drop shape is then decomposed into spherical harmonics, which constitute the eigenmodes of oscillations predicted by the Rayleigh-Lamb theory. Time evolution of each mode is then obtained. The frequency and the damping rate of the principal mode (n=2) are accurately determined and compared with theoretical values for an immobile clean drop oscillating around spherical shape. For pure heptane drops, theoretical value of the frequency agrees well with experiments whereas the damping rate is significantly underestimated by theory. The experimental results clearly show that the differen...

  1. Diabetic retinal imaging: methods in automatic processing

    OpenAIRE

    RUSSELL, GREG

    2015-01-01

    AbstractFundus image based screening for diabetic retinopathy is offered to all diabetic patients aged 12 and older. This has proven to be an effective procedure for the early detection/diagnosis of diabetic retinopathy and forms the basis of current treatment plans. However, the increasing number of diabetic patients is putting a strain on the NHS. Computer based tools to aid detection of/grade diabetic pathologies are currently under development. In this MPhil a novel database of fundus is ...

  2. Angiogenesis in obesity and cancer

    OpenAIRE

    Bråkenhielm, Ebba

    2003-01-01

    Angiogenesis is the process of blood vessel growth from pre-existing vasculatures. In the adult, it is involved in certain physiological processes, such as in organ and tissue regeneration, wound healing, and in female reproductive cycles. Like during embryonic development, the growth and expansion of adult tissues is dependent on neovascularization. The adipose tissue has a unique capacity to substantially increase or decrease in size throughout adult life. This indicates t...

  3. Recent Progress in Therapeutic Angiogenesis

    OpenAIRE

    Nakagami, Hironori; Morishita, Ryuichi

    2007-01-01

    Coronary artery disease and peripheral arterial disease are devastating status of acute vessel occlusion in diseased vessels that are already narrowed enough by atherosclerotic process. People are now focused on therapeutic angiogenesis against the ischemic diseases, to supply and growth of new vessels into the ischemic tissue. Recently, we and others performed autologous transplantation of bone marrow mononuclear cell or endothelial progenitor cell and gene therapy using hepatocyte growth fa...

  4. Osteomyelitis - imaging methods and their ranking

    International Nuclear Information System (INIS)

    Various imaging modalities are used in diagnosis of acute and chronic infectious endogenous osteomyelitis and exogenous ostitis. The pathophysiological changes of osteomyelitis/ostitis in the bone and surrounding soft tissue are known. Findings in plain film radiography show these changes only in relatively advanced stages of disease. Hence, plain film radiographs are useful as a basic imaging modality by excluding other differentials and as a follow-up modality under therapy. Ultrasound -- using advanced technology -- offers diagnostic help in acute osteomyelitis, especially in infants. The various techniques of nuclear medicine show much higher sensitivity for detecting osteomyelitis than plain film radiography, but do not permit good separation for bone involvement and infectious changes in the surrounding soft tissue. While computed tomography offers the ability to display bone and soft tissue separately, it has been widely replaced by magnetic resonance imaging using fat-suppressed sequences and paramagnetic contrast media which show the spread of the infectious changes with higher sensitivity and accuracy. (orig.)

  5. Secure method for sectional image archiving and transmission

    Science.gov (United States)

    Zhou, Xiaoqiang; Huang, H. K.; Lou, Shyhliang A.

    2000-05-01

    Purpose: Data security becomes an important issue in telemedicine when medical information is transmitted over wide area network. Generally, security is characterized in terms of privacy, authenticity and integrity of digital data. We present a method here which can meet the requirements of privacy, authenticity, and integrity for archiving and transmitting of sectional image such as CT, MR. Methods: The method is described as follows: firstly, image segmentation was done and some patient information was read from image DICOM header. Second, a digital signature for the segmented image was produced using the image sender's private key. Afterwards, the digital signature and patient information were concatenated and embedded into the background area of the image. Finally, the whole image was encrypted to form a digital envelope using the receiver's public key. Results: (1) The image can only be decrypted and read by authorized user who own the private key of the receiving site. (2) The authenticity and integrity can be tested by signature verification. Conclusions: The preliminary results demonstrate that the method we presented here is an effective method for secure archiving and transmitting for sectional medical images.

  6. Image formation mechanisms of spherical aberration corrected BF STEM imaging methods

    International Nuclear Information System (INIS)

    In this study, we explore the formation mechanisms of different spherical-aberration (Cs)-corrected bright-field (BF) scanning transmission electron microscope (STEM) imaging methods. The Cs-corrected BF STEM imaging modes are characterised in detail using simulated images and experimental BF STEM images obtained with several types of detectors. The Co3O4 specimen results show that the occupancy, the atomic spacing, and the atomic number of the atoms constituting the atomic columns control image formation in BF STEM imaging, which is used to detect light atomic columns. The middle-angle BF STEM image is crucial in image formation by BF STEM imaging. - Highlights: • We explore the formation mechanisms of diversified Cs-corrected STEM imaging methods. • SrTiO3 and Co3O4 were observed by several BF STEM imaging methods. • MABF STEM plays a key role in image formation for visualising a light atomic column. • Occupancy, spacing and the atomic number in atomic columns control the image formation

  7. A 3D Model Reconstruction Method Using Slice Images

    Institute of Scientific and Technical Information of China (English)

    LI Hong-an; KANG Bao-sheng

    2013-01-01

    Aiming at achieving the high accuracy 3D model from slice images, a new model reconstruction method using slice im-ages is proposed. Wanting to extract the outermost contours from slice images, the method of the improved GVF-Snake model with optimized force field and ray method is employed. And then, the 3D model is reconstructed by contour connection using the im-proved shortest diagonal method and judgment function of contour fracture. The results show that the accuracy of reconstruction 3D model is improved.

  8. An image super-resolution method considering edge character

    International Nuclear Information System (INIS)

    Maximum A Posteriori (MAP) estimation is an important image super-resolution method. However, a clear edge is difficult to maintain. To address this problem, we analyze the causes of poor edge stability. We also present a method for reducing the smoothness of the edge, maintaining the smoothness of the soft regional area, and reducing pseudo noise to improve connected edge retention. The improved method fixes the iteration number and smoothing factor of the MAP estimation by using Gauss-Laplacian image edge extraction. Finally, the validity of this method is verified by its application to feature information recognition in remote sensing images

  9. Research on image matching method of big data image of three-dimensional reconstruction

    Science.gov (United States)

    Zhang, Chunsen; Qiu, Zhenguo; Zhu, Shihuan; Wang, Xiqi; Xu, Xiaolei; Zhong, Sidong

    2015-12-01

    Image matching is the main flow of a three-dimensional reconstruction. With the development of computer processing technology, seeking the image to be matched from the large date image sets which acquired from different image formats, different scales and different locations has put forward a new request for image matching. To establish the three dimensional reconstruction based on image matching from big data images, this paper put forward a new effective matching method based on visual bag of words model. The main technologies include building the bag of words model and image matching. First, extracting the SIFT feature points from images in the database, and clustering the feature points to generate the bag of words model. We established the inverted files based on the bag of words. The inverted files can represent all images corresponding to each visual word. We performed images matching depending on the images under the same word to improve the efficiency of images matching. Finally, we took the three-dimensional model with those images. Experimental results indicate that this method is able to improve the matching efficiency, and is suitable for the requirements of large data reconstruction.

  10. Multi-band Image Registration Method Based on Fourier Transform

    Institute of Scientific and Technical Information of China (English)

    庹红娅; 刘允才

    2004-01-01

    This paper presented a registration method based on Fourier transform for multi-band images which is involved in translation and small rotation. Although different band images differ a lot in the intensity and features,they contain certain common information which we can exploit. A model was given that the multi-band images have linear correlations under the least-square sense. It is proved that the coefficients have no effect on the registration progress if two images have linear correlations. Finally, the steps of the registration method were proposed. The experiments show that the model is reasonable and the results are satisfying.

  11. A method of periodic pattern localization on document images

    Science.gov (United States)

    Chernov, Timofey S.; Nikolaev, Dmitry P.; Kliatskine, Vitali M.

    2015-12-01

    Periodic patterns often present on document images as holograms, watermarks or guilloche elements which are mostly used for fraud protection. Localization of such patterns lets an embedded OCR system to vary its settings depending on pattern presence in particular image regions and improves the precision of pattern removal to preserve as much useful data as possible. Many document images' noise detection and removal methods deal with unstructured noise or clutter on documents with simple background. In this paper we propose a method of periodic pattern localization on document images which uses discrete Fourier transform that works well on documents with complex background.

  12. Image mosaic method based on SIFT features of line segment.

    Science.gov (United States)

    Zhu, Jun; Ren, Mingwu

    2014-01-01

    This paper proposes a novel image mosaic method based on SIFT (Scale Invariant Feature Transform) feature of line segment, aiming to resolve incident scaling, rotation, changes in lighting condition, and so on between two images in the panoramic image mosaic process. This method firstly uses Harris corner detection operator to detect key points. Secondly, it constructs directed line segments, describes them with SIFT feature, and matches those directed segments to acquire rough point matching. Finally, Ransac method is used to eliminate wrong pairs in order to accomplish image mosaic. The results from experiment based on four pairs of images show that our method has strong robustness for resolution, lighting, rotation, and scaling. PMID:24511326

  13. Image Mosaic Method Based on SIFT Features of Line Segment

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2014-01-01

    Full Text Available This paper proposes a novel image mosaic method based on SIFT (Scale Invariant Feature Transform feature of line segment, aiming to resolve incident scaling, rotation, changes in lighting condition, and so on between two images in the panoramic image mosaic process. This method firstly uses Harris corner detection operator to detect key points. Secondly, it constructs directed line segments, describes them with SIFT feature, and matches those directed segments to acquire rough point matching. Finally, Ransac method is used to eliminate wrong pairs in order to accomplish image mosaic. The results from experiment based on four pairs of images show that our method has strong robustness for resolution, lighting, rotation, and scaling.

  14. A rigorous and simpler method of image charges

    Science.gov (United States)

    Ladera, C. L.; Donoso, G.

    2016-07-01

    The method of image charges relies on the proven uniqueness of the solution of the Laplace differential equation for an electrostatic potential which satisfies some specified boundary conditions. Granted by that uniqueness, the method of images is rightly described as nothing but shrewdly guessing which and where image charges are to be placed to solve the given electrostatics problem. Here we present an alternative image charges method that is based not on guessing but on rigorous and simpler theoretical grounds, namely the constant potential inside any conductor and the application of powerful geometric symmetries. The aforementioned required uniqueness and, more importantly, guessing are therefore both altogether dispensed with. Our two new theoretical fundaments also allow the image charges method to be introduced in earlier physics courses for engineering and sciences students, instead of its present and usual introduction in electromagnetic theory courses that demand familiarity with the Laplace differential equation and its boundary conditions.

  15. MR Image Reconstruction Using Block Matching and Adaptive Kernel Methods.

    Directory of Open Access Journals (Sweden)

    Johannes F M Schmidt

    Full Text Available An approach to Magnetic Resonance (MR image reconstruction from undersampled data is proposed. Undersampling artifacts are removed using an iterative thresholding algorithm applied to nonlinearly transformed image block arrays. Each block array is transformed using kernel principal component analysis where the contribution of each image block to the transform depends in a nonlinear fashion on the distance to other image blocks. Elimination of undersampling artifacts is achieved by conventional principal component analysis in the nonlinear transform domain, projection onto the main components and back-mapping into the image domain. Iterative image reconstruction is performed by interleaving the proposed undersampling artifact removal step and gradient updates enforcing consistency with acquired k-space data. The algorithm is evaluated using retrospectively undersampled MR cardiac cine data and compared to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT reconstruction. Evaluation of image quality and root-mean-squared-error (RMSE reveal improved image reconstruction for up to 8-fold undersampled data with the proposed approach relative to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT. In conclusion, block matching and kernel methods can be used for effective removal of undersampling artifacts in MR image reconstruction and outperform methods using standard compressed sensing and ℓ1-regularized parallel imaging methods.

  16. MR Image Reconstruction Using Block Matching and Adaptive Kernel Methods.

    Science.gov (United States)

    Schmidt, Johannes F M; Santelli, Claudio; Kozerke, Sebastian

    2016-01-01

    An approach to Magnetic Resonance (MR) image reconstruction from undersampled data is proposed. Undersampling artifacts are removed using an iterative thresholding algorithm applied to nonlinearly transformed image block arrays. Each block array is transformed using kernel principal component analysis where the contribution of each image block to the transform depends in a nonlinear fashion on the distance to other image blocks. Elimination of undersampling artifacts is achieved by conventional principal component analysis in the nonlinear transform domain, projection onto the main components and back-mapping into the image domain. Iterative image reconstruction is performed by interleaving the proposed undersampling artifact removal step and gradient updates enforcing consistency with acquired k-space data. The algorithm is evaluated using retrospectively undersampled MR cardiac cine data and compared to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT reconstruction. Evaluation of image quality and root-mean-squared-error (RMSE) reveal improved image reconstruction for up to 8-fold undersampled data with the proposed approach relative to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT. In conclusion, block matching and kernel methods can be used for effective removal of undersampling artifacts in MR image reconstruction and outperform methods using standard compressed sensing and ℓ1-regularized parallel imaging methods. PMID:27116675

  17. Iterative methods for dose reduction and image enhancement in tomography

    Science.gov (United States)

    Miao, Jianwei; Fahimian, Benjamin Pooya

    2012-09-18

    A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through modification in object space and Fourier space is disclosed. The invention provides systems and methods for use with any tomographic imaging system that reconstructs an object from its projections. In one embodiment, the invention presents a method to eliminate interpolations present in conventional tomography. The method has been experimentally shown to provide higher resolution and improved image quality parameters over existing approaches. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

  18. Angiogenesis and Anti-Angiogenic Treatments

    Directory of Open Access Journals (Sweden)

    Ersin Demirer

    2013-10-01

    Full Text Available Blood vessels in our body is developed by vasculogenesis and angiogenesis. There have been new advances in molecular pathology and tumor biology areas in recent years. Angiogenesis is modulated by the balance between angiogenic and anti-angiogenic factors. Angiogenesis plays a key role in tumor growth. Drugs inhibiting angiogenesis have been in use in various malign or non-malign diseases. Inhibition of angiogenesis in malign diseases is a very attractive subject in medicine and studies are going on about long term affects and toxicities. Inhibition of angiogenesis is not an only treatment choice alone. It is a supplemental treatment option applied with conventional chemotherapy, radiotherapy, surgery, immunotherapy and hormonal therapy. It has been used in colorectal carcinoma, renal cell carcinoma, non-small cell lung cancer, glioblastoma, heoatocellular carcinoma, pancreatic neuroendocrine tumor, tyroid medullary cancer.

  19. Comparison of two new angiogenesis PET tracers 68Ga-NODAGA-E[c(RGDyK)]2 and 64Cu-NODAGA-E[c(RGDyK)]2; in vivo imaging studies in human xenograft tumors

    DEFF Research Database (Denmark)

    Oxbøl, Jytte; Brandt-Larsen, Malene; Schjøth-Eskesen, Christina;

    2014-01-01

    INTRODUCTION: The aim of this study was to synthesize and perform a side-by-side comparison of two new tumor-angiogenesis PET tracers (68)Ga-NODAGA-E[c(RGDyK)](2) and (64)Cu-NODAGA-E[c(RGDyK)](2) in vivo using human xenograft tumors in mice. Human radiation burden was estimated to evaluate...

  20. Denoising of Medical Images Using Total Variational Method

    Directory of Open Access Journals (Sweden)

    V N Prudhvi Raj

    2012-05-01

    Full Text Available Feature extraction and object recognition from images acquired by various imaging modalities are playingthe key role in diagnosing the various diseases. These operations will become difficult if the images arecorrupted with noise. So the need for developing the efficient algorithms for noise removal became animportant research area today. Developing Image denoising algorithms is a difficult operation because finedetails in a medical image embedding diagnostic information should not be destroyed during noiseremoval. In this paper the total variational method which had success in computational fluid dynamics isadopted to denoise the medical images. We are using split Bregman method from optimisation theory tofind the solution to this non-linear convex optimisation problem. The present approach will outperform indenoising the medical images while compared with the traditional spatial domain filtering methods. Theperformance metrics we used to measure the quality of the denoised images is PSNR (Peak signal to noiseratio.The results showed that these methods are removing the noise effectively while preserving the edgeinformation in the images.

  1. A method of image registration for small animal, multi-modality imaging

    OpenAIRE

    Chow, Patrick L; Stout, David B.; Komisopoulou, Evangelia; Chatziioannou, Arion F

    2006-01-01

    Many research institutions have a full suite of preclinical tomographic scanners to answer biomedical questions in vivo. Routine multi-modality imaging requires robust registration of images generated by various tomographs. We have implemented a hardware registration method for preclinical imaging that is similar to that used in the combined positron emission tomography (PET)/computed tomography (CT) scanners in the clinic. We designed an imaging chamber which can be rigidly and reproducibly ...

  2. Feature fusion method for edge detection of color images

    Institute of Scientific and Technical Information of China (English)

    Ma Yu; Gu Xiaodong; Wang Yuanyuan

    2009-01-01

    A novel feature fusion method is proposed for the edge detection of color images. Except for the typical features used in edge detection, the color contrast similarity and the orientation consistency are also selected as the features. The four features are combined together as a parameter to detect the edges of color images. Experimental results show that the method can inhibit noisy edges and facilitate the detection for weak edges. It has a better performance than conventional methods in noisy environments.

  3. Chemokine Regulation of Angiogenesis During Wound Healing

    OpenAIRE

    Bodnar, Richard J.

    2015-01-01

    Significance: Angiogenesis plays a critical role in wound healing. A defect in the formation of a neovasculature induces ulcer formation. One of the challenges faced by the clinician when devising strategies to promote healing of chronic wounds is the initiation of angiogenesis and the formation of a stable vasculature to support tissue regeneration. Understanding the molecular factors regulating angiogenesis during wound healing will lead to better therapies for healing chronic wounds.

  4. Generalized Row-Action Methods for Tomographic Imaging

    DEFF Research Database (Denmark)

    Andersen, Martin Skovgaard; Hansen, Per Christian

    2014-01-01

    Row-action methods play an important role in tomographic image reconstruction. Many such methods can be viewed as incremental gradient methods for minimizing a sum of a large number of convex functions, and despite their relatively poor global rate of convergence, these methods often exhibit fast...... initial convergence which is desirable in applications where a low-accuracy solution is acceptable. In this paper, we propose relaxed variants of a class of incremental proximal gradient methods, and these variants generalize many existing row-action methods for tomographic imaging. Moreover, they allow...

  5. A Novel Visual Cryptographic Method for Color Images

    Directory of Open Access Journals (Sweden)

    Amarjot Singh

    2013-05-01

    Full Text Available Visual cryptography is considered to be a vital technique for hiding visual data from intruders. Because of its importance, it finds applications in various sectors such as E-voting system, financial documents and copyright protections etc. A number of methods have been proposed in past for encrypting color images such as color decomposition, contrast manipulation, polynomial method, using the difference in color intensity values in a color image etc. The major flaws with most of the earlier proposed methods is the complexity encountered during the implementation of the methods on a wide scale basis, the problem of random pixilation and insertion of noise in encrypted images. This paper presents a simple and highly resistant algorithm for visual cryptography to be performed on color images. The main advantage of the proposed cryptographic algorithm is the robustness and low computational cost with structure simplicity. The proposed algorithm outperformed the conventional methods when tested over sample images proven using key analysis, SSIM and histogram analysis tests. In addition, the proposed method overshadows the standard method in terms of the signal to noise ratio obtained for the encrypted image, which is much better than the SNR value obtained using the standard method. The paper also makes a worst case analysis for the SNR values for both the methods.

  6. Positron emission imaging device and method of using the same

    Science.gov (United States)

    Bingham, Philip R.; Mullens, James Allen

    2013-01-15

    An imaging system and method of imaging are disclosed. The imaging system can include an external radiation source producing pairs of substantially simultaneous radiation emissions of a picturization emission and a verification emissions at an emission angle. The imaging system can also include a plurality of picturization sensors and at least one verification sensor for detecting the picturization and verification emissions, respectively. The imaging system also includes an object stage is arranged such that a picturization emission can pass through an object supported on said object stage before being detected by one of said plurality of picturization sensors. A coincidence system and a reconstruction system can also be included. The coincidence can receive information from the picturization and verification sensors and determine whether a detected picturization emission is direct radiation or scattered radiation. The reconstruction system can produce a multi-dimensional representation of an object imaged with the imaging system.

  7. CMOS image sensor noise reduction method for image signal processor in digital cameras and camera phones

    Science.gov (United States)

    Yoo, Youngjin; Lee, SeongDeok; Choe, Wonhee; Kim, Chang-Yong

    2007-02-01

    Digital images captured from CMOS image sensors suffer Gaussian noise and impulsive noise. To efficiently reduce the noise in Image Signal Processor (ISP), we analyze noise feature for imaging pipeline of ISP where noise reduction algorithm is performed. The Gaussian noise reduction and impulsive noise reduction method are proposed for proper ISP implementation in Bayer domain. The proposed method takes advantage of the analyzed noise feature to calculate noise reduction filter coefficients. Thus, noise is adaptively reduced according to the scene environment. Since noise is amplified and characteristic of noise varies while the image sensor signal undergoes several image processing steps, it is better to remove noise in earlier stage on imaging pipeline of ISP. Thus, noise reduction is carried out in Bayer domain on imaging pipeline of ISP. The method is tested on imaging pipeline of ISP and images captured from Samsung 2M CMOS image sensor test module. The experimental results show that the proposed method removes noise while effectively preserves edges.

  8. A Segmentation Method for Uneven Illumination Particle Images

    OpenAIRE

    Wang Wen-Cheng; Cui Xiao-Jun

    2013-01-01

    To the question of particle images segmentation with uneven illumination background, a novel method is proposed based on homomorphic filtering, Top-Hat transformation and watershed algorithm in this study after discussing the characteristic of various common segmentation algorithms. Firstly, homomorphic filtering is carried out on particle image frequency region space, which weakened low frequency component and strengthened the high frequency component appropriately, to make the whole image e...

  9. Image Post-Processing Method for Visual Data Mining

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Visual data mining is one of important approach of data mining techniques. Most of them are based on computer graphic techniques but few of them exploit image-processing techniques. This paper proposes an image processing method, named RNAM (resemble neighborhood averaging method), to facilitate visual data mining, which is used to post-process the data mining result-image and help users to discover significant features and useful patterns effectively. The experiments show that the method is intuitive, easily-understanding and effectiveness. It provides a new approach for visual data mining.

  10. Effect of speckle on APSCI method and Mueller Imaging

    CERN Document Server

    Upadhyay, Debajyoti; Lacot, Eric; De Martino, Antonello; Orlik, Xavier

    2014-01-01

    The principle of the polarimetric imaging method called APSCI (Adapted Polarization State Contrast Imaging) is to maximize the polarimetric contrast between an object and its background using specific polarization states of illumination and detection. We perform here a comparative study of the APSCI method with existing Classical Mueller Imaging(CMI) associated with polar decomposition in the presence of fully and partially polarized circular Gaussian speckle. The results show a noticeable increase of the Bhattacharyya distance used as our contrast parameter for the APSCI method, especially when the object and background exhibit several polarimetric properties simultaneously.

  11. Advances in the Simultaneous Multiple Surface optical design method for imaging and non-imaging applications

    OpenAIRE

    Wang, Lin

    2012-01-01

    Classical imaging optics has been developed over centuries in many areas, such as its paraxial imaging theory and practical design methods like multi-parametric optimization techniques. Although these imaging optical design methods can provide elegant solutions to many traditional optical problems, there are more and more new design problems, like solar concentrator, illumination system, ultra-compact camera, etc., that require maximum energy transfer efficiency, or ultra-compact optical stru...

  12. Texture recognition of medical images with the ICM method

    International Nuclear Information System (INIS)

    The Integrated Cortical Model (ICM) is based upon several models of the mammalian visual cortex and produces pulse images over several iterations. These pulse images tend to isolate segments, edges, and textures that are inherent in the input image. To create a texture recognition engine the pulse spectrum of individual pixels are collected and used to develop a recognition library. Recognition is performed by comparing pulse spectra of unclassified regions of images with the known regions. Because signatures are smaller than images, signature-based computation is quite efficient and parasites can be recognized quickly. The precision of this method depends on the representative of signatures and classification. Our experiment results support the theoretical findings and show perspectives of practical applications of ICM-based method. The advantage of ICM method is using signatures to represent objects. ICM can extract the internal features of objects and represent them with signatures. Signature classification is critical for the precision of recognition

  13. Matrix-based image reconstruction methods for tomography

    International Nuclear Information System (INIS)

    Matrix methods of image reconstruction have not been used, in general, because of the large size of practical matrices, ill condition upon inversion and the success of Fourier-based techniques. An exception is the work that has been done at the Lawrence Berkeley Laboratory for imaging with accelerated radioactive ions. An extension of that work into more general imaging problems shows that, with a correct formulation of the problem, positron tomography with ring geometries results in well behaved matrices which can be used for image reconstruction with no distortion of the point response in the field of view and flexibility in the design of the instrument. Maximum Likelihood Estimator methods of reconstruction, which use the system matrices tailored to specific instruments and do not need matrix inversion, are shown to result in good preliminary images. A parallel processing computer structure based on multiple inexpensive microprocessors is proposed as a system to implement the matrix-MLE methods. 14 references, 7 figures

  14. Super pixel density based clustering automatic image classification method

    Science.gov (United States)

    Xu, Mingxing; Zhang, Chuan; Zhang, Tianxu

    2015-12-01

    The image classification is an important means of image segmentation and data mining, how to achieve rapid automated image classification has been the focus of research. In this paper, based on the super pixel density of cluster centers algorithm for automatic image classification and identify outlier. The use of the image pixel location coordinates and gray value computing density and distance, to achieve automatic image classification and outlier extraction. Due to the increased pixel dramatically increase the computational complexity, consider the method of ultra-pixel image preprocessing, divided into a small number of super-pixel sub-blocks after the density and distance calculations, while the design of a normalized density and distance discrimination law, to achieve automatic classification and clustering center selection, whereby the image automatically classify and identify outlier. After a lot of experiments, our method does not require human intervention, can automatically categorize images computing speed than the density clustering algorithm, the image can be effectively automated classification and outlier extraction.

  15. Research of Anti-Noise Image Salient Region Extraction Method

    Directory of Open Access Journals (Sweden)

    Bing XU

    2014-01-01

    Full Text Available The existing image salient region extraction technology is mostly suitable for processing noise-free images, and there is a lack of studies on the impact of noise on images. In this study the adaptive kernel function was employed in image salient region detection. The salient property of a region was determined by the dissimilarities between the pixels of the image region and its surroundings. The dissimilarity was measured as a decreasing function associated with adaptive kernel regression. The proposed algorithm used multi-scale fusion method to obtain the salient region of the whole image. As adaptive kernel function has strong anti-noise characteristics, the proposed algorithm was characterized with the same robustness. A numerical simulation experiment was conducted on salient region extraction of images with noise and without noise. A comparison between this study’s results and two existing salient region extraction methods revealed that the proposed method in this study was superior in its extraction accuracy of image salient regions and could reduce interference of image noise.

  16. A new in vivo model using a dorsal skinfold chamber to investigate microcirculation and angiogenesis in diabetic wounds

    Directory of Open Access Journals (Sweden)

    Langer, Stefan

    2016-02-01

    Full Text Available Introduction: Diabetes mellitus describes a dysregulation of glucose metabolism due to improper insulin secretion, reduced insulin efficacy or both. It is a well-known fact that diabetic patients are likely to suffer from impaired wound healing, as diabetes strongly affects tissue angiogenesis. Until now, no satisfying in vivo murine model has been established to analyze the dynamics of angiogenesis during diabetic wound healing. To help understand the pathophysiology of diabetes and its effect on angiogenesis, a novel in vivo murine model was established using the skinfold chamber in mice.Materials and Methods: Mutant diabetic mice (db; wildtype mice ( and laboratory BALB/c mice were examined. They were kept in single cages with access to laboratory chow with an 12/12 hour day/night circle. Lesions of the panniculus muscle (Ø 2 mm were created in the center of the transparent window chamber and the subsequent muscular wound healing was then observed for a period of 22 days. Important analytic parameters included vessel diameter, red blood cell velocity, vascular permeability, and leakage of muscle capillaries and post capillary venules. The key parameters were functional capillary density (FCD and angiogenesis positive area (APA.Results: We established a model which allows high resolution in vivo imaging of functional angiogenesis in diabetic wounds. As expected, db mice showed impaired wound closure (day 22 compared to wounds of BALB/c or WT mice (day 15. FCD was lower in diabetic mice compared to WT and BALB/c during the entire observation period. The dynamics of angiogenesis also decreased in db mice, as reflected by the lowest APA levels. Significant variations in the skin buildup were observed, with the greatest skin depth in db mice. Furthermore, in db mice, the dermis:subcutaneous ratio was highly shifted towards the subcutaneous layers as opposed to WT or BALB/c mice.Conclusion: Using this new in vivo model of the skinfold chamber, it

  17. Method and apparatus for imaging and documenting fingerprints

    Science.gov (United States)

    Fernandez, Salvador M.

    2002-01-01

    The invention relates to a method and apparatus for imaging and documenting fingerprints. A fluorescent dye brought in intimate proximity with the lipid residues of a latent fingerprint is caused to fluoresce on exposure to light energy. The resulting fluorescing image may be recorded photographically.

  18. A Novel Image Fusion Method Based on FRFT-NSCT

    Directory of Open Access Journals (Sweden)

    Peiguang Wang

    2013-01-01

    fused image is obtained by performing the inverse NSCT and inverse FRFT on the combined coefficients. Three modes images and three fusion rules are demonstrated in the proposed algorithm test. The simulation results show that the proposed fusion approach is better than the methods based on NSCT at the same parameters.

  19. Method and apparatus for improving the alignment of radiographic images

    International Nuclear Information System (INIS)

    This invention relates generally to the field of radiology, and has to do particularly with a method and apparatus for improving the alignment of radiographic images taken at different times of the same tissue structure, so that the images can be sequentially shown in aligned condition, whereby changes in the structure can be noted. (author). 10 figs

  20. Dehazing method through polarimetric imaging and multi-scale analysis

    Science.gov (United States)

    Cao, Lei; Shao, Xiaopeng; Liu, Fei; Wang, Lin

    2015-05-01

    An approach for haze removal utilizing polarimetric imaging and multi-scale analysis has been developed to solve one problem that haze weather weakens the interpretation of remote sensing because of the poor visibility and short detection distance of haze images. On the one hand, the polarization effects of the airlight and the object radiance in the imaging procedure has been considered. On the other hand, one fact that objects and haze possess different frequency distribution properties has been emphasized. So multi-scale analysis through wavelet transform has been employed to make it possible for low frequency components that haze presents and high frequency coefficients that image details or edges occupy are processed separately. According to the measure of the polarization feather by Stokes parameters, three linear polarized images (0°, 45°, and 90°) have been taken on haze weather, then the best polarized image min I and the worst one max I can be synthesized. Afterwards, those two polarized images contaminated by haze have been decomposed into different spatial layers with wavelet analysis, and the low frequency images have been processed via a polarization dehazing algorithm while high frequency components manipulated with a nonlinear transform. Then the ultimate haze-free image can be reconstructed by inverse wavelet reconstruction. Experimental results verify that the dehazing method proposed in this study can strongly promote image visibility and increase detection distance through haze for imaging warning and remote sensing systems.

  1. CMOS low data rate imaging method based on compressed sensing

    Science.gov (United States)

    Xiao, Long-long; Liu, Kun; Han, Da-peng

    2012-07-01

    Complementary metal-oxide semiconductor (CMOS) technology enables the integration of image sensing and image compression processing, making improvements on overall system performance possible. We present a CMOS low data rate imaging approach by implementing compressed sensing (CS). On the basis of the CS framework, the image sensor projects the image onto a separable two-dimensional (2D) basis set and measures the corresponding coefficients obtained. First, the electrical current output from the pixels in a column are combined, with weights specified by voltage, in accordance with Kirchhoff's law. The second computation is performed in an analog vector-matrix multiplier (VMM). Each element of the VMM considers the total value of each column as the input and multiplies it by a unique coefficient. Both weights and coefficients are reprogrammable through analog floating-gate (FG) transistors. The image can be recovered from a percentage of these measurements using an optimization algorithm. The percentage, which can be altered flexibly by programming on the hardware circuit, determines the image compression ratio. These novel designs facilitate image compression during the image-capture phase before storage, and have the potential to reduce power consumption. Experimental results demonstrate that the proposed method achieves a large image compression ratio and ensures imaging quality.

  2. A Frequency Splitting Method For CFM Imaging

    DEFF Research Database (Denmark)

    Udesen, Jesper; Gran, Fredrik; Jensen, Jørgen Arendt

    estimator. In the simulation, the relative mean standard deviation of the velocity estimates over the vessel was 2.43% when using the FD method and the relative mean absolute bias was 1.84%. For the reference 8 oscillation pulse, the relative mean standard deviation over the vessel was 4.91 % and the...... relative mean absolute bias was 1.78%. In the experiments the relative mean standard deviation of the velocity estimates over the vessel was 2.41 % when using the FD method and the relative- mean absolute bias was 1.56%. For the reference 8 oscillation pulse, the relative mean standard deviation over the...

  3. IMPROVING THE QUALITY OF NEAR-INFRARED IMAGING OF IN VIVOBLOOD VESSELS USING IMAGE FUSION METHODS

    DEFF Research Database (Denmark)

    Jensen, Andreas Kryger; Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2009-01-01

    We investigate methods for improving the visual quality of in vivo images of blood vessels in the human forearm. Using a near-infrared light source and a dual CCD chip camera system capable of capturing images at visual and nearinfrared spectra, we evaluate three fusion methods in terms of their...... capability of enhancing the blood vessels while preserving the spectral signature of the original color image. Furthermore, we investigate a possibility of removing hair in the images using a fusion rule based on the "a trous" stationary wavelet decomposition. The method with the best overall performance...... with both speed and quality in mind is the Intensity Injection method. Using the developed system and the methods presented in this article, it is possible to create images of high visual quality with highly emphasized blood vessels....

  4. A Novel Steganography Method for Hiding BW Images into Gray Bitmap Images via k-Modulus Method

    Directory of Open Access Journals (Sweden)

    Firas A. Jassim

    2013-09-01

    Full Text Available This paper is to create a pragmatic steganographic implementation to hide black and white image which is known as stego image inside another gray bitmap image that known as cover image. First of all, the proposed technique uses k-Modulus Method (K-MM to convert all pixels within the cover image into multiples of positive integer named k. Since the black and white images can be represented using binary representation, i.e. 0 or 1. Then, in this article, the suitable value for the positive integer k is two. Therefore, each pixel inside the cover image is divisible by two and this produces a reminder which is either 0 or 1. Subsequently, the black and white representation of the stego image could be hidden inside the cover image. The ocular differences between the cover image before and after adding the stego image are insignificant. The experimental results show that the PSNR values for the cover image are very high with very small Mean Square Error.

  5. Image segmentation with a finite element method

    DEFF Research Database (Denmark)

    Bourdin, Blaise

    1999-01-01

    regularization results, make possible to imagine a finite element resolution method.In a first time, the Mumford-Shah functional is introduced and some existing results are quoted. Then, a discrete formulation for the Mumford-Shah problem is proposed and its $\\Gamma$-convergence is proved. Finally, some...

  6. Intra-laboratory validation of a human cell based in vitro angiogenesis assay for testing angiogenesis modulators

    Directory of Open Access Journals (Sweden)

    Jertta-Riina Sarkanen

    2011-01-01

    Full Text Available The developed standardized human cell based in vitro angiogenesis assay was intra-laboratory validated to verify that the method is reliable and relevant for routine testing of modulators of angiogenesis e.g. pharmaceuticals and industrial chemicals. This assay is based on the earlier published method but it was improved and shown to be more sensitive and rapid than the previous assay. The performance of the assay was assessed by using 6 reference chemicals, which are widely used pharmaceuticals that inhibit angiogenesis: acetyl salicylic acid, erlotinib, 2-methoxyestradiol, levamisole, thalidomide, and anti-vascular endothelial growth factor. In the intra-laboratory validation, the sensitivity of the assay (upper and lower limits of detection and linearity of response in tubule formation, batch to batch variation in tubule formation between different Master cell bank batches, and precision as well as the reliability of the assay (reproducibility and repeatability were tested. The pre-set acceptance criteria for the intra-laboratory validation study were met. The relevance of the assay in man was investigated by comparing the effects of reference chemicals and their concentrations to the published human data. The comparison showed a good concordance, which indicates that this human cell based angiogenesis model predicts well the effects in man and has the potential to be used to supplement and/or replace of animal tests.

  7. A method of fast mosaic for massive UAV images

    Science.gov (United States)

    Xiang, Ren; Sun, Min; Jiang, Cheng; Liu, Lei; Zheng, Hui; Li, Xiaodong

    2014-11-01

    With the development of UAV technology, UAVs are used widely in multiple fields such as agriculture, forest protection, mineral exploration, natural disaster management and surveillances of public security events. In contrast of traditional manned aerial remote sensing platforms, UAVs are cheaper and more flexible to use. So users can obtain massive image data with UAVs, but this requires a lot of time to process the image data, for example, Pix4UAV need approximately 10 hours to process 1000 images in a high performance PC. But disaster management and many other fields require quick respond which is hard to realize with massive image data. Aiming at improving the disadvantage of high time consumption and manual interaction, in this article a solution of fast UAV image stitching is raised. GPS and POS data are used to pre-process the original images from UAV, belts and relation between belts and images are recognized automatically by the program, in the same time useless images are picked out. This can boost the progress of finding match points between images. Levenberg-Marquard algorithm is improved so that parallel computing can be applied to shorten the time of global optimization notably. Besides traditional mosaic result, it can also generate superoverlay result for Google Earth, which can provide a fast and easy way to show the result data. In order to verify the feasibility of this method, a fast mosaic system of massive UAV images is developed, which is fully automated and no manual interaction is needed after original images and GPS data are provided. A test using 800 images of Kelan River in Xinjiang Province shows that this system can reduce 35%-50% time consumption in contrast of traditional methods, and increases respond speed of UAV image processing rapidly.

  8. Single sideband methods in Fresnel zone plate imaging

    International Nuclear Information System (INIS)

    A single sideband zone plate system appears to have a more satisfactory transfer function than a double sideband on-axis zone plate system. The real image and virtual image sidebands occupy different regions of the transfer function and so the unwanted real image can be filtered from the virtual image. However diffraction coherent reconstruction is not ideal for single sideband holograms because of phase distortion produced as a result of using only one of the two sidebands. Correlative reconstruction methods are able to make use of both sidebands and so neither produce phase distortion nor result in the wasting of any signal information

  9. a Minimum Spanning Tree Based Method for Uav Image Segmentation

    Science.gov (United States)

    Wang, Ping; Wei, Zheng; Cui, Weihong; Lin, Zhiyong

    2016-06-01

    This paper proposes a Minimum Span Tree (MST) based image segmentation method for UAV images in coastal area. An edge weight based optimal criterion (merging predicate) is defined, which based on statistical learning theory (SLT). And we used a scale control parameter to control the segmentation scale. Experiments based on the high resolution UAV images in coastal area show that the proposed merging predicate can keep the integrity of the objects and prevent results from over segmentation. The segmentation results proves its efficiency in segmenting the rich texture images with good boundary of objects.

  10. A Proposed Method for Image Steganography using Edge Detection

    Directory of Open Access Journals (Sweden)

    Sanyam Anand

    2013-06-01

    Full Text Available In this paper, we proposed a technique to hide the text data into the color images using edge detection method. The alteration in edges cannot be distinguished well so edges can hide more data without losing quality of an image. In this technique, Edges of an image are detected by scanning using 3x3 window and then text message is concealed in edges using first component alteration technique. The proposed scheme achieved high embedding capacity and high quality of encoded image.

  11. Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

    OpenAIRE

    Kuang Tsan Lin; Sheng Lih Yeh

    2014-01-01

    The Rivest-Shamir-Adleman (RSA) encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matri...

  12. Single Molecule Imaging in Living Cell with Optical Method

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Significance, difficult, international developing actuality and our completed works for single molecules imaging in living cell with optical method are described respectively. Additionally we give out some suggestions for the technology development further.

  13. IMAGE PROCESSING METHOD TO MEASURE SUGARCANE LEAF AREA

    Directory of Open Access Journals (Sweden)

    Sanjay B. Patil

    2011-08-01

    Full Text Available In order to increase the average sugarcane yield per acres with minimum cost farmers are adapting precision farming technique. This paper includes the area measurement of sugarcane leaf based on image processing method which is useful for plants growth monitoring, to analyze fertilizer deficiency and environmental stress,to measure diseases severity. In image processing method leaf area is calculated through pixel number statistic. Unit pixel in the same digital images represent the same size hence from known reference area and pixel count, unit pixel size can calculate, so that it is easy to calculate leaf area by counting total pixel in leaf area region. The results are compared with the results of graphical area measurement method. The experimentally it is proved that image processing method for measuring sugarcane leaf area is accurate and strong practicabilitywith small relative error.

  14. Modified wavelet kernel methods for hyperspectral image classification

    Science.gov (United States)

    Hsu, Pai-Hui; Huang, Xiu-Man

    2015-10-01

    Hyperspectral images have the capability of acquiring images of earth surface with several hundred of spectral bands. Providing such abundant spectral data should increase the abilities in classifying land use/cover type. However, due to the high dimensionality of hyperspectral data, traditional classification methods are not suitable for hyperspectral data classification. The common method to solve this problem is dimensionality reduction by using feature extraction before classification. Kernel methods such as support vector machine (SVM) and multiple kernel learning (MKL) have been successfully applied to hyperspectral images classification. In kernel methods applications, the selection of kernel function plays an important role. The wavelet kernel with multidimensional wavelet functions can find the optimal approximation of data in feature space for classification. The SVM with wavelet kernels (called WSVM) have been also applied to hyperspectral data and improve classification accuracy. In this study, wavelet kernel method combined multiple kernel learning algorithm and wavelet kernels was proposed for hyperspectral image classification. After the appropriate selection of a linear combination of kernel functions, the hyperspectral data will be transformed to the wavelet feature space, which should have the optimal data distribution for kernel learning and classification. Finally, the proposed methods were compared with the existing methods. A real hyperspectral data set was used to analyze the performance of wavelet kernel method. According to the results the proposed wavelet kernel methods in this study have well performance, and would be an appropriate tool for hyperspectral image classification.

  15. Cancer gene therapy targeting angiogenesis: An updated review

    OpenAIRE

    Liu, Ching-Chiu; Shen, Zan; Kung, Hsiang-Fu; Lin, Marie CM

    2006-01-01

    Since the relationship between angiogenesis and tumor growth was established by Folkman in 1971, scientists have made efforts exploring the possibilities in treating cancer by targeting angiogenesis. Inhibition of angiogenesis growth factors and administration of angiogenesis inhibitors are the basics of anti-angiogenesis therapy. Transfer of anti-angiogenesis genes has received attention recently not only because of the advancement of recombinant vectors, but also because of the localized an...

  16. New molecular connections in angiogenesis

    Institute of Scientific and Technical Information of China (English)

    Qiling Xu; David Wilkinson

    2010-01-01

    @@ In vertebrates, oxygen and nutrients are delivered to tissues by the circula-tion of blood through vessels, comprised of a branched network of endothelial tubes termed the vasculature. Crucial for the formation of blood vessels during development is the process of angiogenesis, in which new sprouts form from pre-existing vessels in a complex cascade of cellular events. This involves the activation of an endothelial cell in the vessel to become a highly exploratory 'tip' cell that migrates to invade the surrounding tissues, while remaining tightly connected to the fol-lowing cells that subsequently generate the tubular structures of a new vessel.

  17. Imaging of turbid media using trajectory filter methods

    OpenAIRE

    Pfeiffer, Nicholas

    2009-01-01

    Optical imaging through biological tissues and other scattering media is challenging, as the scattered light creates an extremely high background noise level that makes it difficult to detect objects that are embedded within the media. This thesis examines a relatively unexplored method of separating scattered light from unscattered light that has application to optical imaging through turbid media. The method creates an optical filter that blocks photons based upon their exit trajectory dire...

  18. Development of root observation method by image analysis system

    OpenAIRE

    Kim, Giyoung

    1995-01-01

    Knowledge of plant roots is important for determining plant-soil relationships, managing soil effectively, studying nutrient and water extraction, and creating a soil quality index. Plant root research is limited by the large amount of time and labor required to wash the roots from the soil and measure the viable roots. A root measurement method based on image analysis was proposed to reduce the time and labor requirement. A thinning algorithm-based image analysis method was us...

  19. Cardiac MR image segmentation using CHNN and level set method

    Institute of Scientific and Technical Information of China (English)

    王洪元; 周则明; 王平安; 夏德深

    2004-01-01

    Although cardiac magnetic resonance imaging (MRI) can provide high spatial resolution image, the area gray level inhomogenization, weak boundary and artifact often can be found in MR images. So, the MR images segmentation using the gradient-based methods is poor in quality and efficiency. An algorithm, based on the competitive hopfield neural network (CHNN) and the curve propagation, is proposed for cardiac MR images segmentation in this paper. The algorithm is composed of two phases. In first phase, a CHNN is used to classify the image objects, and to make gray level homogenization and to recognize weak boundaries in objects. In second phase, based on the classified results, the level set velocity function is created and the object boundaries are extracted with the curve propagation algorithm of the narrow band-based level set. The test results are promising and encouraging.

  20. Narrowband imaging method for spatial precession cone-shaped targets

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The imaging method of the mid-course missile is the key technique of the missile defense system.Because of the special precession character of the ballistic missile warhead,the inverse synthetic aperture radar method cannot realize phase compensation with the constant phase offset function,which leads to blurring of the image.In this paper,we propose a new narrowband radar imaging method for the precession cone-shaped targets.The method acquires the Doppler modulation of the precession target’s scattering centers with high resolution time-frequency analysis method and extracts the Doppler parameter from the result of the time-frequency analysis with the general Radon transform,then reconstructs the scattering centers positions in the parameter domain.The experiment results with the anechoic chamber data of the representative cone-shaped object showed the effectiveness of the method.

  1. 2-dimensional neutron imaging method using scintillators with WLS fibers

    International Nuclear Information System (INIS)

    It is necessary to develop neutron diffractometers and spectrometers with high-performance neutron imaging devices for neutron scattering experiments using a high intense pulsed-neutron source. These imaging devices require excellent time resolution, high counting rate, high detection efficiency, wide dynamic range, and large imaging area in order to carry out neutron scattering experiments with time of flight (TOF) method. Especially, the general materials diffractometer for powder diffraction and disordered materials require the imaging device with a large area, high counting rate, high efficiency, and position resolution less than a few mm. Moreover, the devices require simplicity and compactness for easy assemble and easy maintenance as an experimental system. According to these requirements, we propose a novel neutron imaging method using rectangular scintillators with wavelength shifting (WLS) fibers. (author)

  2. Performance analysis of image fusion methods in transform domain

    Science.gov (United States)

    Choi, Yoonsuk; Sharifahmadian, Ershad; Latifi, Shahram

    2013-05-01

    Image fusion involves merging two or more images in such a way as to retain the most desirable characteristics of each. There are various image fusion methods and they can be classified into three main categories: i) Spatial domain, ii) Transform domain, and iii) Statistical domain. We focus on the transform domain in this paper as spatial domain methods are primitive and statistical domain methods suffer from a significant increase of computational complexity. In the field of image fusion, performance analysis is important since the evaluation result gives valuable information which can be utilized in various applications, such as military, medical imaging, remote sensing, and so on. In this paper, we analyze and compare the performance of fusion methods based on four different transforms: i) wavelet transform, ii) curvelet transform, iii) contourlet transform and iv) nonsubsampled contourlet transform. Fusion framework and scheme are explained in detail, and two different sets of images are used in our experiments. Furthermore, various performance evaluation metrics are adopted to quantitatively analyze the fusion results. The comparison results show that the nonsubsampled contourlet transform method performs better than the other three methods. During the experiments, we also found out that the decomposition level of 3 showed the best fusion performance, and decomposition levels beyond level-3 did not significantly affect the fusion results.

  3. Method and apparatus to image biological interactions in plants

    Science.gov (United States)

    Weisenberger, Andrew; Bonito, Gregory M.; Reid, Chantal D.; Smith, Mark Frederick

    2015-12-22

    A method to dynamically image the actual translocation of molecular compounds of interest in a plant root, root system, and rhizosphere without disturbing the root or the soil. The technique makes use of radioactive isotopes as tracers to label molecules of interest and to image their distribution in the plant and/or soil. The method allows for the study and imaging of various biological and biochemical interactions in the rhizosphere of a plant, including, but not limited to, mycorrhizal associations in such regions.

  4. Methods for processing and analysis functional and anatomical brain images: computerized tomography, emission tomography and nuclear resonance imaging

    International Nuclear Information System (INIS)

    The various methods for brain image processing and analysis are presented and compared. The following topics are developed: the physical basis of brain image comparison (nature and formation of signals intrinsic performance of the methods image characteristics); mathematical methods for image processing and analysis (filtering, functional parameter extraction, morphological analysis, robotics and artificial intelligence); methods for anatomical localization (neuro-anatomy atlas, proportional stereotaxic atlas, numerized atlas); methodology of cerebral image superposition (normalization, retiming); image networks

  5. Intravital Fluorescence Videomicroscopy to Study Tumor Angiogenesis and Microcirculation

    Directory of Open Access Journals (Sweden)

    Peter Vajkoczy

    2000-01-01

    Full Text Available Angiogenesis and microcirculation play a central role in growth and metastasis of human neoplasms, and, thus, represent a major target for novel treatment strategies. Mechanistic analysis of processes involved in tumor vascularization, however, requires sophisticated in vivo experimental models and techniques. Intravital microscopy allows direct assessment of tumor angiogenesis, microcirculation and overall perfusion. Its application to the study of tumor-induced neovascularization further provides information on molecular transport and delivery, intra- and extravascular cell-to-cell and cell-tomatrix interaction, as well as tumor oxygenation and metabolism. With the recent advances in the field of bioluminescence and fluorescent reporter genes, appropriate for in vivo imaging, the intravital fluorescent microscopic approach has to be considered a powerful tool to study microvascular, cellular and molecular mechanisms of tumor growth.

  6. Screw thread parameter measurement system based on image processing method

    Science.gov (United States)

    Rao, Zhimin; Huang, Kanggao; Mao, Jiandong; Zhang, Yaya; Zhang, Fan

    2013-08-01

    In the industrial production, as an important transmission part, the screw thread is applied extensively in many automation equipments. The traditional measurement methods of screw thread parameter, including integrated test methods of multiparameters and the single parameter measurement method, belong to contact measurement method. In practical the contact measurement exists some disadvantages, such as relatively high time cost, introducing easily human error and causing thread damage. In this paper, as a new kind of real-time and non-contact measurement method, a screw thread parameter measurement system based on image processing method is developed to accurately measure the outside diameter, inside diameter, pitch diameter, pitch, thread height and other parameters of screw thread. In the system the industrial camera is employed to acquire the image of screw thread, some image processing methods are used to obtain the image profile of screw thread and a mathematics model is established to compute the parameters. The C++Builder 6.0 is employed as the software development platform to realize the image process and computation of screw thread parameters. For verifying the feasibility of the measurement system, some experiments were carried out and the measurement errors were analyzed. The experiment results show the image measurement system satisfies the measurement requirements and suitable for real-time detection of screw thread parameters mentioned above. Comparing with the traditional methods the system based on image processing method has some advantages, such as, non-contact, easy operation, high measuring accuracy, no work piece damage, fast error analysis and so on. In the industrial production, this measurement system can provide an important reference value for development of similar parameter measurement system.

  7. Curcumin inhibition of angiogenesis and adipogenesis

    Science.gov (United States)

    The growth of new blood vessels or angiogenesis is necessary for the growth of adipose tissue. Adipokines produced by fat cells stimulate this process. Some dietary polyphenols with antiangiogenic activity may suppress adipose tissue growth not only by inhibiting angiogenesis, but also by interferin...

  8. Complex role of matrix metalloproteinases in angiogenesis

    Institute of Scientific and Technical Information of China (English)

    SANGQINGXIANGAMY

    1998-01-01

    Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a significant role in regulating angiogenesis,the process of new blood vessel formation.Interstitial collagenase (MMP-1),72kDa gelatinase A/type IV collagenase (MMP-2),and 92 kDA gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and promote angiogenesis.TIMP-1,TIMP-2,TIMP-3,and possibly,TIMP-4 inhibit neovascularization.A new paradign is emerging that matrilysin (MMP-7),MMP-9,and metalloelastase (MMP-12) may block angiogenesis by converting plasminogen to angiostatin,which is one of the most potent angiogenesis antagonists.MMPs and TIMPs play a complex role in regulating angiogenesis.An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide important information to allow the control of angiogenesis,e.g.the stimulation of angiogenesis for coronary collateral circulation formation;while the inhibition for treating arthritis and cancer.

  9. A Secret Image Sharing Method Using Integer Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Li Ching-Chung

    2007-01-01

    Full Text Available A new image sharing method, based on the reversible integer-to-integer (ITI wavelet transform and Shamir's threshold scheme is presented, that provides highly compact shadows for real-time progressive transmission. This method, working in the wavelet domain, processes the transform coefficients in each subband, divides each of the resulting combination coefficients into shadows, and allows recovery of the complete secret image by using any or more shadows . We take advantages of properties of the wavelet transform multiresolution representation, such as coefficient magnitude decay and excellent energy compaction, to design combination procedures for the transform coefficients and processing sequences in wavelet subbands such that small shadows for real-time progressive transmission are obtained. Experimental results demonstrate that the proposed method yields small shadow images and has the capabilities of real-time progressive transmission and perfect reconstruction of secret images.

  10. Misalignment-robust, edge-based image fusion method

    Science.gov (United States)

    Xi, Cai; Wei, Zhao

    2012-07-01

    We propose an image fusion method robust to misaligned source images based on their multiscale edge representations. Significant long edge curves at the second scale are selected to decide edge locations at each scale for the multiscale edge representations of source images. Then, processes are only executed on the representations that contain the main spatial structures of the images and also help suppress noise interference. A registration process is embedded in our fusion method. Edge correlation, calculated at the second scale, is involved as a match measure determining the fusion rules and also as a similarity measure quantifying the matching extent between source images, which makes the registration and fusion processes share the same data and hence lessens the computation of our method. Experimental results prove that, no matter whether in a noiseless or noisy condition, the proposed method provides satisfying treatment to misregistered source images and behaves well in terms of visual and objective evaluations on the fusion results, which further verifies the robustness of our edge-based method to misregistration and noise.

  11. A Simple Fusion Method for Image Time Series Based on the Estimation of Image Temporal Validity

    Directory of Open Access Journals (Sweden)

    Mar Bisquert

    2015-01-01

    Full Text Available High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two input images (H and L, which are weighted by their temporal validity to the image to be fused. The method was applied to two years (2009–2010 of Landsat and MODIS (MODerate Imaging Spectroradiometer images that were acquired over a cropped area in Brazil. The fusion method was evaluated at global and local scales. The results show that the fused images reproduced reliable crop temporal profiles and correctly delineated the boundaries between two neighboring fields. The greatest advantages of the proposed method are the execution time and ease of use, which allow us to obtain a fused image in less than five minutes.

  12. New adaptive sampling method in particle image velocimetry

    International Nuclear Information System (INIS)

    This study proposes a new adaptive method to enable the number of interrogation windows and their positions in a particle image velocimetry (PIV) image interrogation algorithm to become self-adapted according to the seeding density. The proposed method can relax the constraint of uniform sampling rate and uniform window size commonly adopted in the traditional PIV algorithm. In addition, the positions of the sampling points are redistributed on the basis of the spring force generated by the sampling points. The advantages include control of the number of interrogation windows according to the local seeding density and smoother distribution of sampling points. The reliability of the adaptive sampling method is illustrated by processing synthetic and experimental images. The synthetic example attests to the advantages of the sampling method. Compared with that of the uniform interrogation technique in the experimental application, the spatial resolution is locally enhanced when using the proposed sampling method. (technical design note)

  13. A Simple Image Encoding Method with Data Lossless Information Hiding

    Directory of Open Access Journals (Sweden)

    Zhi-Hui Wang

    2011-03-01

    Full Text Available In this paper, we propose a simple reversible data hiding method in the spatial domain for block truncation coding (BTC compressed grayscale images. The BTC method compresses a block of a grayscale image to a bitmap and a pair of quantization numbers. The proposed method first embeds secret bits into a block by changing the order of those two quantization numbers. The compression rate is not enlarged by this embedding scheme. To further improve the hiding capacity, the proposed method embeds the secret bits into the bitmap of the block by exploiting the correlation characteristic of neighboring blocks’ bitmap in natural images. The experimental results show that the proposed method achieves very good hiding capacity at low compression rate.

  14. Study on the Medical Image Distributed Dynamic Processing Method

    Institute of Scientific and Technical Information of China (English)

    张全海; 施鹏飞

    2003-01-01

    To meet the challenge of implementing rapidly advanced, time-consuming medical image processing algorithms,it is necessary to develop a medical image processing technology to process a 2D or 3D medical image dynamically on the web. But in a premier system, only static image processing can be provided with the limitation of web technology. The development of Java and CORBA (common object request broker architecture) overcomes the shortcoming of the web static application and makes the dynamic processing of medical images on the web available. To develop an open solution of distributed computing, we integrate the Java, and web with the CORBA and present a web-based medical image dynamic processing methed, which adopts Java technology as the language to program application and components of the web and utilies the CORBA architecture to cope with heterogeneous property of a complex distributed system. The method also provides a platform-independent, transparent processing architecture to implement the advanced image routines and enable users to access large dataset and resources according to the requirements of medical applications. The experiment in this paper shows that the medical image dynamic processing method implemented on the web by using Java and the CORBA is feasible.

  15. The expression of osteopontin and vascular endothelial growth factor in correlation with angiogenesis in monoclonal gammopathy of undetermined significance and multiple myeloma.

    Science.gov (United States)

    Babarović, Emina; Valković, Toni; Budisavljević, Ivana; Balen, Ivan; Štifter, Sanja; Duletić-Načinović, Antica; Lučin, Ksenija; Jonjić, Nives

    2016-06-01

    Several studies have shown a gradual increase in the extent of bone marrow angiogenesis in various stages of proliferative plasma cell disorders, from monoclonal gammopathy of undetermined significance (MGUS) to active multiple myeloma (MM). The main aim of this study was to evaluate tumor angiogenesis parameters in detail and to correlate them with the expression of osteopontin (OPN) and vascular endothelial growth factor (VEGF) in the bone marrow of patients with MGUS and MM. In addition, we wanted to determine their prognostic significance in active MM. Ninety-five patients were enrolled in the study: 14 diagnosed with MGUS, 13 with asymptomatic myeloma (AMM) and 68 with active MM. Computer assisted image analysis was used to determine the angiogenesis parameters, the quantity of microvessels per 1mm(2) (MVD), the area occupied by microvessels per 1mm(2) and the percentage of microvessel area in total section area (TVA). Double immunohistochemical methods CD138+VEGF and CD138+OPN were used to evaluate expression of these proteins in plasma cells, and OPN was also analyzed for its interstitial expression (iOPN). A significant positive correlation was determined between VEGF and iOPN with angiogenic parameters in the MGUS stage of the disease. In advanced stages of the disease, a significant negative correlation was recorded between OPN and iOPN with parameters of angiogenesis. Overall survival was significantly shorter for patients with negative iOPN (p=0.002) and higher angiogenic parameters, MVD (p=0.009), TVA (p=0.008) and area of microvessels per 1mm(2) (p=0.02). Positive VEGF expression in our model predicted a better three-year survival of patients with active MM (OR: 5.25, p=0.03; HR: 0.44, p=0.04). The results of our study suggested a possible key role of VEGF and OPN in the induction of angiogenesis in early-stage disease. PMID:26997492

  16. Research of x-ray automatic image mosaic method

    Science.gov (United States)

    Liu, Bin; Chen, Shunan; Guo, Lianpeng; Xu, Wanpeng

    2013-10-01

    Image mosaic has widely applications value in the fields of medical image analysis, and it is a technology that carries on the spatial matching to a series of image which are overlapped with each other, and finally builds a seamless and high quality image which has high resolution and big eyeshot. In this paper, the method of grayscale cutting pseudo-color enhancement was firstly used to complete the mapping transformation from gray to the pseudo-color, and to extract SIFT features from the images. And then by making use of a similar measure of NCC (normalized cross correlation - Normalized cross-correlation), the method of RANSAC (Random Sample Consensus) was used to exclude the pseudofeature points right in order to complete the exact match of feature points. Finally, seamless mosaic and color fusion were completed by using wavelet multi-decomposition. The experiment shows that the method we used can effectively improve the precision and automation of the medical image mosaic, and provide an effective technical approach for automatic medical image mosaic.

  17. Dirichlet Methods for Bayesian Source Detection in Radio Astronomy Images

    Science.gov (United States)

    Friedlander, A. M.

    2014-02-01

    The sheer volume of data to be produced by the next generation of radio telescopes - exabytes of data on hundreds of millions of objects - makes automated methods for the detection of astronomical objects ("sources") essential. Of particular importance are low surface brightness objects, which are not well found by current automated methods. This thesis explores Bayesian methods for source detection that use Dirichlet or multinomial models for pixel intensity distributions in discretised radio astronomy images. A novel image discretisation method that incorporates uncertainty about how the image should be discretised is developed. Latent Dirichlet allocation - a method originally developed for inferring latent topics in document collections - is used to estimate source and background distributions in radio astronomy images. A new Dirichlet-multinomial ratio, indicating how well a region conforms to a well-specified model of background versus a loosely-specified model of foreground, is derived. Finally, latent Dirichlet allocation and the Dirichlet-multinomial ratio are combined for source detection in astronomical images. The methods developed in this thesis perform source detection well in comparison to two widely-used source detection packages and, importantly, find dim sources not well found by other algorithms.

  18. A Surface Approximation Method for Image and Video Correspondences.

    Science.gov (United States)

    Huang, Jingwei; Wang, Bin; Wang, Wenping; Sen, Pradeep

    2015-12-01

    Although finding correspondences between similar images is an important problem in image processing, the existing algorithms cannot find accurate and dense correspondences in images with significant changes in lighting/transformation or with the non-rigid objects. This paper proposes a novel method for finding accurate and dense correspondences between images even in these difficult situations. Starting with the non-rigid dense correspondence algorithm [1] to generate an initial correspondence map, we propose a new geometric filter that uses cubic B-Spline surfaces to approximate the correspondence mapping functions for shared objects in both images, thereby eliminating outliers and noise. We then propose an iterative algorithm which enlarges the region containing valid correspondences. Compared with the existing methods, our method is more robust to significant changes in lighting, color, or viewpoint. Furthermore, we demonstrate how to extend our surface approximation method to video editing by first generating a reliable correspondence map between a given source frame and each frame of a video. The user can then edit the source frame, and the changes are automatically propagated through the entire video using the correspondence map. To evaluate our approach, we examine applications of unsupervised image recognition and video texture editing, and show that our algorithm produces better results than those from state-of-the-art approaches. PMID:26241974

  19. A Quick and Affine Invariance Matching Method for Oblique Images

    Directory of Open Access Journals (Sweden)

    XIAO Xiongwu

    2015-04-01

    Full Text Available This paper proposed a quick, affine invariance matching method for oblique images. It calculated the initial affine matrix by making full use of the two estimated camera axis orientation parameters of an oblique image, then recovered the oblique image to a rectified image by doing the inverse affine transform, and left over by the SIFT method. We used the nearest neighbor distance ratio(NNDR, normalized cross correlation(NCC measure constraints and consistency check to get the coarse matches, then used RANSAC method to calculate the fundamental matrix and the homography matrix. And we got the matches that they were interior points when calculating the homography matrix, then calculated the average value of the matches' principal direction differences. During the matching process, we got the initial matching features by the nearest neighbor(NN matching strategy, then used the epipolar constrains, homography constrains, NCC measure constrains and consistency check of the initial matches' principal direction differences with the calculated average value of the interior matches' principal direction differences to eliminate false matches. Experiments conducted on three pairs of typical oblique images demonstrate that our method takes about the same time as SIFT to match a pair of oblique images with a plenty of corresponding points distributed evenly and an extremely low mismatching rate.

  20. Reconstruction of CT images by the Bayes- back projection method

    CERN Document Server

    Haruyama, M; Takase, M; Tobita, H

    2002-01-01

    In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. From the basic theory of Baysian Back Projection method, it can be not only applied to CT types of 1st, 2nd, and 3rd generation. This reported deals with a reconstruction program of cross-section images in the CT of ...

  1. A comparison of 3D-CTA and 4D-CE-MRA for the dynamic monitoring of angiogenesis in a rabbit VX2 tumor

    International Nuclear Information System (INIS)

    Purpose: To compare three-dimensional computed tomography angiography (3D-CTA) and four-dimensional contrast-enhanced magnetic resonance angiography (4D-CE-MRA) for the in vivo monitoring of tumor angiogenesis. Materials and methods: VX2 tumors were implanted into the right thigh muscle of 30 New Zealand white rabbits. The animals were randomly assigned to 5 groups, which, respectively, were scanned by 3D-CTA and 4D-CE-MRA on day 4, 7, 10, 13, or 16 after tumor implantation. After scanning, tumors were resected and processed for conventional histology and CD-31 immunohistochemistry. Tumor volume measurements derived from CT and MR imaging were compared with histopathological data. The minimum tumor diameter and the number of new tumor blood vessels detectable by 3D-CTA and 4D-CE-MRA were also compared. Results: There were no significant differences in the tumor volume measurements derived from CT, MR, and histological analysis. The minimum diameter of tumor vessels detectable by 3D-CTA (0.68 ± 0.07 mm) was significantly less than that by 4D-CE-MRA (0.85 ± 0.12 mm) (P = 0.005). The number of tumor vessels detected by each imaging method was not significantly different until day 13 after implantation, when 3D-CTA detected a greater number (P < 0.001). The morphologic process of tumor angiogenesis was demonstrated dynamically by 3D-CTA and 4D-CE-MRA in vivo. Conclusions: Tumor angiogenesis can be dynamically monitored in vivo by 3D-CTA and 4D-CE-MRA. Of the two methods, 3D-CTA has better spatial resolution, but 4D-CE-MRA allows temporal resolution of tumor angiogenesis.

  2. Application of Non-Iterative Method in Image Deblurring

    Directory of Open Access Journals (Sweden)

    MILADINOVIC Marko

    2012-05-01

    Full Text Available This paper presents a non-iterative method thatfinds application in a broad scientific field such as imagedeblurring. A method for image deblurring, based on thepseudo-inverse matrix is apply for removal of blurr inan image caused by linear motion. This methodassumes that linear motion corresponds to an integralnumber of pixels. Compared to other classicalmethods, this method attains higher values of theImprovement in Signal to Noise Ratio (ISNRparameter and of the Peak Signal-to-Noise Ratio(PSNR. We give an implementation in the MATLABprogramming package.

  3. Image Watermarking Method Using Integer-to-Integer Wavelet Transforms

    Institute of Scientific and Technical Information of China (English)

    陈韬; 王京春

    2002-01-01

    Digital watermarking is an efficient method for copyright protection for text, image, audio, and video data. This paper presents a new image watermarking method based on integer-to-integer wavelet transforms. The watermark is embedded in the significant wavelet coefficients by a simple exclusive OR operation. The method avoids complicated computations and high computer memory requirements that are the main drawbacks of common frequency domain based watermarking algorithms. Simulation results show that the embedded watermark is perceptually invisible and robust to various operations, such as low quality joint picture expert group (JPEG) compression, random and Gaussian noises, and smoothing (mean filtering).

  4. PRECL: A new method for interferometry imaging from closure phase

    Science.gov (United States)

    Ikeda, Shiro; Tazaki, Fumie; Akiyama, Kazunori; Hada, Kazuhiro; Honma, Mareki

    2016-06-01

    For short-wavelength VLBI observations, it is difficult to measure the phase of the visibility function accurately. The closure phases are reliable measurements under this situation, though it is not sufficient to retrieve all of the phase information. We propose a new method, phase retrieval from closure phase (PRECL). PRECL estimates all the visibility phases only from the closure phases. Combining PRECL with a sparse modeling method we have already proposed, the imaging process of VLBI does not rely on a dirty image or self-calibration. The proposed method is tested numerically and the results are promising.

  5. Magnetic rotation imaging method to measure the geomagnetic field

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new imaging method for measuring the geomagnetic field based on the magnetic rotation effect is put forward. With the help of polarization property of the sunlight reflected from the ground and the magnetic rotation of the atmosphere, the geomagnetic field can be measured by an optical system installed on a satellite. According to its principle, the three-dimensional image of the geomagnetic field can be obtained. The measuring speed of this method is very high, and there is no blind spot and distortion. In this paper, the principle of this method is presented, and some key problems are discussed.

  6. PRECL: A new method for interferometry imaging from closure phase

    CERN Document Server

    Ikeda, Shiro; Akiyama, Kazunori; Hada, Kazuhiro; Honma, Mareki

    2016-01-01

    For short-wavelength VLBI observations, it is difficult to measure the phase of the visibility function accurately. The closure phases are reliable measurements under this situation, though it is not sufficient to retrieve all of the phase information. We propose a new method, Phase Retrieval from Closure Phase (PRECL). PRECL estimates all the visibility phases only from the closure phases. Combining PRECL with a sparse modeling method we have already proposed, imaging process of VLBI does not rely on dirty image nor self-calibration. The proposed method is tested numerically and the results are promising.

  7. An Improved Image Segmentation Algorithm Based on MET Method

    Directory of Open Access Journals (Sweden)

    Z. A. Abo-Eleneen

    2012-09-01

    Full Text Available Image segmentation is a basic component of many computer vision systems and pattern recognition. Thresholding is a simple but effective method to separate objects from the background. A commonly used method, Kittler and Illingworth's minimum error thresholding (MET, improves the image segmentation effect obviously. Its simpler and easier to implement. However, it fails in the presence of skew and heavy-tailed class-conditional distributions or if the histogram is unimodal or close to unimodal. The Fisher information (FI measure is an important concept in statistical estimation theory and information theory. Employing the FI measure, an improved threshold image segmentation algorithm FI-based extension of MET is developed. Comparing with the MET method, the improved method in general can achieve more robust performance when the data for either class is skew and heavy-tailed.

  8. New learning subspace method for image feature extraction

    Institute of Scientific and Technical Information of China (English)

    CAO Jian-hai; LI Long; LU Chang-hou

    2006-01-01

    A new method of Windows Minimum/Maximum Module Learning Subspace Algorithm(WMMLSA) for image feature extraction is presented. The WMMLSM is insensitive to the order of the training samples and can regulate effectively the radical vectors of an image feature subspace through selecting the study samples for subspace iterative learning algorithm,so it can improve the robustness and generalization capacity of a pattern subspace and enhance the recognition rate of a classifier. At the same time,a pattern subspace is built by the PCA method. The classifier based on WMMLSM is successfully applied to recognize the pressed characters on the gray-scale images. The results indicate that the correct recognition rate on WMMLSM is higher than that on Average Learning Subspace Method,and that the training speed and the classification speed are both improved. The new method is more applicable and efficient.

  9. Consistency-based ellipse detection method for complicated images

    Science.gov (United States)

    Zhang, Lijun; Huang, Xuexiang; Feng, Weichun; Liang, Shuli; Hu, Tianjian

    2016-05-01

    Accurate ellipse detection in complicated images is a challenging problem due to corruptions from image clutter, noise, or occlusion of other objects. To cope with this problem, an edge-following-based ellipse detection method is proposed which promotes the performances of the subprocesses based on consistency. The ellipse detector models edge connectivity by line segments and exploits inconsistent endpoints of the line segments to split the edge contours into smooth arcs. The smooth arcs are further refined with a novel arc refinement method which iteratively improves the consistency degree of the smooth arc. A two-phase arc integration method is developed to group disconnected elliptical arcs belonging to the same ellipse, and two constraints based on consistency are defined to increase the effectiveness and speed of the merging process. Finally, an efficient ellipse validation method is proposed to evaluate the saliency of the elliptic hypotheses. Detailed evaluation on synthetic images shows that our method outperforms other state-of-the-art ellipse detection methods in terms of effectiveness and speed. Additionally, we test our detector on three challenging real-world datasets. The F-measure score and execution time of results demonstrate that our method is effective and fast in complicated images. Therefore, the proposed method is suitable for practical applications.

  10. Apparatus and method for motion tracking in brain imaging

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is apparatus and method for motion tracking of a subject in medical brain imaging. The method comprises providing a light projector and a first camera; projecting a first pattern sequence (S1) onto a surface region of the subject with the light projector, wherein the subject is positioned...

  11. Proinflammatory mediators stimulate neutrophil-directed angiogenesis.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF. HYPOTHESIS: The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis. METHODS: Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis. RESULTS: Lipopolysaccharide and TNF-alpha stimulation resulted in significantly increased release of PMN VEGF (532+\\/-49 and 484+\\/-80 pg\\/mL, respectively; for all, presented as mean +\\/- SEM) compared with control experiments (32+\\/-4 pg\\/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti-human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store. CONCLUSION: Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome

  12. Neural cell image segmentation method based on support vector machine

    Science.gov (United States)

    Niu, Shiwei; Ren, Kan

    2015-10-01

    In the analysis of neural cell images gained by optical microscope, accurate and rapid segmentation is the foundation of nerve cell detection system. In this paper, a modified image segmentation method based on Support Vector Machine (SVM) is proposed to reduce the adverse impact caused by low contrast ratio between objects and background, adherent and clustered cells' interference etc. Firstly, Morphological Filtering and OTSU Method are applied to preprocess images for extracting the neural cells roughly. Secondly, the Stellate Vector, Circularity and Histogram of Oriented Gradient (HOG) features are computed to train SVM model. Finally, the incremental learning SVM classifier is used to classify the preprocessed images, and the initial recognition areas identified by the SVM classifier are added to the library as the positive samples for training SVM model. Experiment results show that the proposed algorithm can achieve much better segmented results than the classic segmentation algorithms.

  13. Single Transducer Ultrasonic Imaging Method that Eliminates the Effect of Plate Thickness Variation in the Image

    Science.gov (United States)

    Roth, Don J.

    1996-01-01

    This article describes a single transducer ultrasonic imaging method that eliminates the effect of plate thickness variation in the image. The method thus isolates ultrasonic variations due to material microstructure. The use of this method can result in significant cost savings because the ultrasonic image can be interpreted correctly without the need for machining to achieve precise thickness uniformity during nondestructive evaluations of material development. The method is based on measurement of ultrasonic velocity. Images obtained using the thickness-independent methodology are compared with conventional velocity and c-scan echo peak amplitude images for monolithic ceramic (silicon nitride), metal matrix composite and polymer matrix composite materials. It was found that the thickness-independent ultrasonic images reveal and quantify correctly areas of global microstructural (pore and fiber volume fraction) variation due to the elimination of thickness effects. The thickness-independent ultrasonic imaging method described in this article is currently being commercialized under a cooperative agreement between NASA Lewis Research Center and Sonix, Inc.

  14. Ultrasound contrast image segmentation using a modified level set method.

    Science.gov (United States)

    Qian, Ming; Niu, Lili; Xiao, Yang; Wang, Congzhi; Qiu, Weibao; Zheng, Hairong

    2013-01-01

    Manual segmentation of ultrasound contrast images is time-consuming and inevitable to variability, and computer-based segmentation algorithms often require user interaction. This paper proposes a novel level set model for fully automated segmentation of vascular ultrasound contrast images. The initial contour of arterial boundaries is acquired based on an automatic procedure. The level set model moves the initial contour towards the boundaries of arterial inner wall based on minimization of the energy function. The traditional energy function is improved by introducing an edge detector based on image gradient and the standard difference image. Both spatial and temporal information of the image are considered, and the robustness and accuracy of the level set model is enhanced. Ultrasonic contrast images of living mouse are acquitted with high frequency ultrasound system. Images of carotid arteries are processed with our method. The segmentation results using the proposed method are evaluated against two observers' hand-outlined boundaries, showing that computer-generated boundaries agree well with the observers' hand-outlined boundaries as much as the different observers agree with each other. PMID:24110889

  15. Scanning-fiber-based imaging method for tissue engineering

    Science.gov (United States)

    Hofmann, Matthias C.; Whited, Bryce M.; Mitchell, Josh; Vogt, William C.; Criswell, Tracy; Rylander, Christopher; Rylander, Marissa Nichole; Soker, Shay; Wang, Ge; Xu, Yong

    2012-06-01

    A scanning-fiber-based method developed for imaging bioengineered tissue constructs such as synthetic carotid arteries is reported. Our approach is based on directly embedding one or more hollow-core silica fibers within the tissue scaffold to function as micro-imaging channels (MIC). The imaging process is carried out by translating and rotating an angle-polished fiber micro-mirror within the MIC to scan excitation light across the tissue scaffold. The locally emitted fluorescent signals are captured using an electron multiplying CCD camera and then mapped into fluorophore distributions according to fiber micro-mirror positions. Using an optical phantom composed of fluorescent microspheres, tissue scaffolds, and porcine skin, we demonstrated single-cell-level imaging resolution (20 to 30 μm) at an imaging depth that exceeds the photon transport mean free path by one order of magnitude. This result suggests that the imaging depth is no longer constrained by photon scattering, but rather by the requirement that the fluorophore signal overcomes the background ``noise'' generated by processes such as scaffold autofluorescence. Finally, we demonstrated the compatibility of our imaging method with tissue engineering by visualizing endothelial cells labeled with green fluorescent protein through a ~500 μm thick and highly scattering electrospun scaffold.

  16. A Lossy Method for Compressing Raw CCD Images

    CERN Document Server

    Watson, A M

    2002-01-01

    This paper describes a lossy method for compressing raw images produced by CCDs or similar devices. The method is very simple: lossy quantization followed by lossless compression using general-purpose compression tools such as gzip and bzip2. A key feature of the method is that compressed images can be converted to FITS files simply by decompressing with gunzip or bunzip2, and this is a significant advantage for distributing compressed files. The degree of quantization is chosen to eliminate low-order bits that over-sample the noise, contain no information, and are difficult or impossible to compress. The method is lossy but gives guarantees on the maximum absolute difference, the expected mean difference, and the expected RMS difference between the compressed and original images; these guarantees make it suitable for use on raw images. The method consistently compresses images to roughly 1/5 of their original size with a quantization such that no value changes by more than 1/2 of a standard deviation in the ...

  17. Cross-relaxation imaging:methods, challenges and applications

    International Nuclear Information System (INIS)

    An overview of quantitative magnetization transfer (qMT) is given, with focus on cross relaxation imaging (CRI) as a fast method for quantifying the proportion of protons bound to complex macromolecules in tissue. The procedure for generating CRI maps is outlined, showing examples in the human brain and knee, and discussing the caveats and challenges in generating precise and accurate CRI maps. Finally, several applications of CRI for imaging tissue microstructure are presented.(Author)

  18. PET imaging of the autonomic myocardial function: methods and interpretation

    OpenAIRE

    Noordzij, Walter; Slart, Riemer H.J.A.

    2015-01-01

    Cardiac positron emission tomography (PET) is mainly applied in myocardial perfusion and viability detection. Noninvasive imaging of myocardial innervation using PET is a valuable additional methodology in cardiac imaging. Novel methods and different PET ligands have been developed to measure presynaptic and postsynaptic function of the cardiac neuronal system. Obtained PET data can be analysed quantitatively or interpreted qualitatively. Thus far, PET is not a widely used clinical applicatio...

  19. Research Dynamics of the Classification Methods of Remote Sensing Images

    OpenAIRE

    Zhang, Yan; Wu, Baoguo; Wang, Dong

    2013-01-01

    As the key technology of extracting remote sensing information, the classification of remote sensing images has always been the research focus in the field of remote sensing. The paper introduces the classification process and system of remote sensing images. According to the recent research status of domestic and international remote sensing classification methods, the new study dynamics of remote sensing classification, such as artificial neural networks, support vector machine, active lear...

  20. Interpretation of the method of images in estimating superconducting levitation

    International Nuclear Information System (INIS)

    Among different papers devoted to superconducting levitation of a permanent magnet over a superconductor using the method of images, there is a discrepancy of a factor of two when estimating the lift force. This is not a minor matter but an interesting fundamental question that contributes to understanding the physical phenomena of 'imaging' on a superconductor surface. We solve it, make clear the physical behavior underlying it, and suggest the reinterpretation of some previous experiments

  1. Methods for identification of images acquired with digital cameras

    Science.gov (United States)

    Geradts, Zeno J.; Bijhold, Jurrien; Kieft, Martijn; Kurosawa, Kenji; Kuroki, Kenro; Saitoh, Naoki

    2001-02-01

    From the court we were asked whether it is possible to determine if an image has been made with a specific digital camera. This question has to be answered in child pornography cases, where evidence is needed that a certain picture has been made with a specific camera. We have looked into different methods of examining the cameras to determine if a specific image has been made with a camera: defects in CCDs, file formats that are used, noise introduced by the pixel arrays and watermarking in images used by the camera manufacturer.

  2. Research Dynamics of the Classification Methods of Remote Sensing Images

    Institute of Scientific and Technical Information of China (English)

    Yan; ZHANG; Baoguo; WU; Dong; WANG

    2013-01-01

    As the key technology of extracting remote sensing information,the classification of remote sensing images has always been the research focus in the field of remote sensing. The paper introduces the classification process and system of remote sensing images. According to the recent research status of domestic and international remote sensing classification methods,the new study dynamics of remote sensing classification,such as artificial neural networks,support vector machine,active learning and ensemble multi-classifiers,were introduced,providing references for the automatic and intelligent development of remote sensing images classification.

  3. Stereo-imaging sensor position localization method and system

    OpenAIRE

    Vardy, A.N.

    2015-01-01

    The disclosure relates to a method and system wherein sensors on a cap or directly disposed on a head can be localized using a stereo camera. By capturing a plurality of stereo images, the positions of the sensors can be determined with respect to each other. At least a first stereo image having a first set of sensors and a second stereo image having a second set of sensors are captured in a first position respectively a second position of the stereo camera relative to the cap by a relative r...

  4. An adaptive image denoising method based on local parameters optimization

    Indian Academy of Sciences (India)

    Hari Om; Mantosh Biswas

    2014-08-01

    In image denoising algorithms, the noise is handled by either modifying term-by-term, i.e., individual pixels or block-by-block, i.e., group of pixels, using suitable shrinkage factor and threshold function. The shrinkage factor is generally a function of threshold and some other characteristics of the neighbouring pixels of the pixel to be thresholded (denoised). The threshold is determined in terms of the noise variance present in the image and its size. The VisuShrink, SureShrink, and NeighShrink methods are important denoising methods that provide good results. The first two, i.e., VisuShrink and SureShrink methods follow term-by-term approach, i.e., modify the individual pixel and the third one, i.e., NeighShrink and its variants: ModiNeighShrink, IIDMWD, and IAWDMBMC, follow block-by-block approach, i.e., modify the pixels in groups, in order to remove the noise. The VisuShrink, SureShrink, and NeighShrink methods however do not give very good visual quality because they remove too many coefficients due to their high threshold values. In this paper, we propose an image denoising method that uses the local parameters of the neighbouring coefficients of the pixel to be denoised in the noisy image. In our method, we propose two new shrinkage factors and the threshold at each decomposition level, which lead to better visual quality. We also establish the relationship between both the shrinkage factors. We compare the performance of our method with that of the VisuShrink and NeighShrink including various variants. Simulation results show that our proposed method has high peak signal-to-noise ratio and good visual quality of the image as compared to the traditional methods:Weiner filter, VisuShrink, SureShrink, NeighBlock, NeighShrink, ModiNeighShrink, LAWML, IIDMWT, and IAWDMBNC methods.

  5. Method for the reduction of image content redundancy in large image databases

    Science.gov (United States)

    Tobin, Kenneth William; Karnowski, Thomas P.

    2010-03-02

    A method of increasing information content for content-based image retrieval (CBIR) systems includes the steps of providing a CBIR database, the database having an index for a plurality of stored digital images using a plurality of feature vectors, the feature vectors corresponding to distinct descriptive characteristics of the images. A visual similarity parameter value is calculated based on a degree of visual similarity between features vectors of an incoming image being considered for entry into the database and feature vectors associated with a most similar of the stored images. Based on said visual similarity parameter value it is determined whether to store or how long to store the feature vectors associated with the incoming image in the database.

  6. On the pinned field image binarization for signature generation in image ownership verification method

    Directory of Open Access Journals (Sweden)

    Chang Hsuan

    2011-01-01

    Full Text Available Abstract The issue of pinned field image binarization for signature generation in the ownership verification of the protected image is investigated. The pinned field explores the texture information of the protected image and can be employed to enhance the watermark robustness. In the proposed method, four optimization schemes are utilized to determine the threshold values for transforming the pinned field into a binary feature image, which is then utilized to generate an effective signature image. Experimental results show that the utilization of optimization schemes can significantly improve the signature robustness from the previous method (Lee and Chang, Opt. Eng. 49 (9, 097005, 2010. While considering both the watermark retrieval rate and the computation speed, the genetic algorithm is strongly recommended. In addition, compared with Chang and Lin's scheme (J. Syst. Softw. 81 (7, 1118-1129, 2008, the proposed scheme also has better performance.

  7. Fingerprint image enhancement method using directional median filter

    Science.gov (United States)

    Wu, Chaohong; Shi, Zhixin; Govindaraju, Venu

    2004-08-01

    The performance of any fingerprint recognizer highly depends on the fingerprint image quality. Different types of noises in the fingerprint images pose greater difficulty for recognizers. Most Automatic Fingerprint Identification Systems (AFIS) use some form of image enhancement. Although several methods have been described in the literature, there is still scope for improvement. In particular, effective methodology of cleaning the valleys between the ridge contours are lacking. We observe that noisy valley pixels and the pixels in the interrupted ridge flow gap are "impulse noises". Therefore, this paper describes a new approach to fingerprint image enhancement, which is based on integration of Anisotropic Filter and directional median filter(DMF). Gaussian-distributed noises are reduced effectively by Anisotropic Filter, "impulse noises" are reduced efficiently by DMF. Usually, traditional median filter is the most effective method to remove pepper-and-salt noise and other small artifacts, the proposed DMF can not only finish its original tasks, it can also join broken fingerprint ridges, fill out the holes of fingerprint images, smooth irregular ridges as well as remove some annoying small artifacts between ridges. The enhancement algorithm has been implemented and tested on fingerprint images from FVC2002. Images of varying quality have been used to evaluate the performance of our approach. We have compared our method with other methods described in the literature in terms of matched minutiae, missed minutiae, spurious minutiae, and flipped minutiae(between end points and bifurcation points). Experimental results show our method to be superior to those described in the literature.

  8. Endostatin, an angiogenesis inhibitor, ameliorates bleomycin-induced pulmonary fibrosis in rats

    OpenAIRE

    Wan, Yun-Yan; Tian, Guang-Yan; Guo, Hai-Sheng; Kang, Yan-Meng; Yao, Zhou-Hong; Li, Xi-Li; Liu, Qing-Hua; Lin, Dian-Jie

    2013-01-01

    Background Recent evidence has demonstrated the role of angiogenesis in the pathogenesis of pulmonary fibrosis. Endostatin, a proteolytic fragment of collagen XVIII, is a potent inhibitor of angiogenesis. The aim of our study was to assess whether endostatin has beneficial effects on bleomycin (BLM)-induced pulmonary fibrosis in rats. Methods The rats were randomly divided into five experimental groups: (A) saline only, (B) BLM only, (C) BLM plus early endostatin treatment, (D) BLM plus late ...

  9. Early exercise improves cerebral blood flow through increased angiogenesis in experimental stroke rat model

    OpenAIRE

    Zhang, Pengyue; Yu, Huixian; Zhou, Naiyun; Jie ZHANG; Wu, Yi; Zhang, Yuling; Bai, Yulong; Jia, Jie; Zhang, Qi; Tian, Shan; Wu, Junfa; Hu, Yongshan

    2013-01-01

    Background Early exercise after stroke promoted angiogenesis and increased microvessles density. However, whether these newly formatted vessels indeed give rise to functional vascular and improve the cerebral blood flow (CBF) in impaired brain region is still unclear. The present study aimed to determine the effect of early exercise on angiogenesis and CBF in ischemic region. Methods Adult male Sprague Dawley rats were subjected to 90 min middle cerebral artery occlusion(MCAO)and randomly div...

  10. Identification of colorectal cancer metastasis markers by an angiogenesis-related cytokine-antibody array

    OpenAIRE

    Abajo, A.; Bitarte, N; Zarate, R; Boni, V; Lopez, I; Gonzalez-Huarriz, M. (Marisol); Rodriguez, J.; Bandres, E; Garcia-Foncillas, J.

    2012-01-01

    AIM: To investigate the angiogenesis-related protein expression profile characterizing metastatic colorectal cancer (mCRC) with the aim of identifying prognostic markers. METHODS: The expression of 44 angiogenesis-secreted factors was measured by a novel cytokine antibody array methodology. The study evaluated vascular endothelial growth factor (VEGF) and its soluble vascular endothelial growth factor receptor (sVEGFR)-1 protein levels by enzyme immunoassay (EIA) in a panel of 16 CRC...

  11. Platelet-Stored Angiogenesis Factors: Clinical Monitoring Is Prone to Artifacts

    OpenAIRE

    Patrick Starlinger; Lejla Alidzanovic; Dominic Schauer; Philipp Brugger; Silvia Sommerfeldt; Irene Kuehrer; Schoppmann, Sebastian F; Michael Gnant; Christine Brostjan

    2011-01-01

    Background: The analysis of angiogenesis factors in the blood of tumor patients has given diverse results on their prognostic or predictive value. Since mediators of angiogenesis are stored in platelets, their measurement in plasma is sensitive to inadvertent platelet activation during blood processing. Methods: Variants of blood withdrawal and plasma preparation were evaluated by ELISA for the detection of TSP-1, PF-4, VEGF and PD-ECGF. A total of 22 pancreatic cancer patients and 29 healthy...

  12. Forkhead Transcription Factor FOXO1 Inhibits Angiogenesis in Gastric Cancer in Relation to SIRT1

    OpenAIRE

    Kim, Sue Youn; Ko, Young San; Park, Jinju; Choi, Yiseul; Park, Jong-Wan; Kim, Younghoon; Pyo, Jung-Soo; Yoo, Young Bok; Lee, Jae-Seon; Lee, Byung Lan

    2015-01-01

    Purpose We previously reported that forkhead transcription factors of the O class 1 (FOXO1) expression in gastric cancer (GC) was associated with angiogenesis-related molecules. However, there is little experimental evidence for the direct role of FOXO1 in GC. In the present study, we investigated the effect of FOXO1 on the tumorigenesis and angiogenesis in GC and its relationship with SIRT1. Materials and Methods Stable GC cell lines (SNU-638 and SNU-601) infected with a lentivirus containin...

  13. Tropoelastin incorporation into a dermal regeneration template promotes wound angiogenesis.

    Science.gov (United States)

    Wang, Yiwei; Mithieux, Suzanne M; Kong, Yvonne; Wang, Xue-Qing; Chong, Cassandra; Fathi, Ali; Dehghani, Fariba; Panas, Eleni; Kemnitzer, John; Daniels, Robert; Kimble, Roy M; Maitz, Peter K; Li, Zhe; Weiss, Anthony S

    2015-03-11

    Severe burn injury results in substantial skin loss and cannot be treated by autografts. The Integra Dermal Regeneration Template (IDRT) is the leading synthetic skin substitute because it allows for wound bed regeneration and wound healing. However, all substitutes suffer from slow blood vessel ingrowth and would benefit considerably from enhanced vascularization to nurture tissue repair. It is shown here that by incorporating the human elastic protein tropoelastin into a dermal regeneration template (TDRT) we can promote angiogenesis in wound healing. In small and large animal models comprising mice and pigs, the hybrid TDRT biomaterial and IDRT show similar contraction to autografts and decrease wound contraction compared to open wounds. In mice, TDRT accelerates early stage angiogenesis by 2 weeks, as evidenced by increased angiogenesis fluorescent radiant efficiency in live animal imaging and the expression of endothelial cell adhesion marker CD146. In the pig, a full thickness wound repair model confirms increased numbers of blood vessels in the regenerating areas of the dermis closest to the hypodermis and immediately below the epidermis at 2 weeks post-surgery. It is concluded that including tropoelastin in a dermal regeneration template has the potential to promote wound repair through enhanced vascularization. PMID:25469903

  14. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Tomoyoshi; Shuto, Kiyohiko; Okazumi, Shinichi; Hayano, Kohichi; Satoh, Asami; Saitoh, Hiroshige; Shimada, Hideaki; Nabeya, Yoshihiro; Matsubara, Hisahiro [Chiba University, Department of Frontier Surgery, Graduate School of Medicine, Chiba (Japan); Kazama, Toshiki [Chiba University, Department of Radiology, Graduate School of Medicine, Chiba (Japan)

    2012-06-15

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  15. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    International Nuclear Information System (INIS)

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  16. Domain decomposition methods for solving an image problem

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, W.K.; Tong, C.S. [Hong Kong Baptist College (Hong Kong)

    1994-12-31

    The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

  17. SAR Data Fusion Imaging Method Oriented to Target Feature Extraction

    Directory of Open Access Journals (Sweden)

    Yang Wei

    2015-02-01

    Full Text Available To deal with the difficulty for target outlines extracting precisely due to neglect of target scattering characteristic variation during the processing of high-resolution space-borne SAR data, a novel fusion imaging method is proposed oriented to target feature extraction. Firstly, several important aspects that affect target feature extraction and SAR image quality are analyzed, including curved orbit, stop-and-go approximation, atmospheric delay, and high-order residual phase error. Furthermore, the corresponding compensation methods are addressed as well. Based on the analysis, the mathematical model of SAR echo combined with target space-time spectrum is established for explaining the space-time-frequency change rule of target scattering characteristic. Moreover, a fusion imaging strategy and method under high-resolution and ultra-large observation angle range conditions are put forward to improve SAR quality by fusion processing in range-doppler and image domain. Finally, simulations based on typical military targets are used to verify the effectiveness of the fusion imaging method.

  18. A novel optical gating method for laser gated imaging

    Science.gov (United States)

    Ginat, Ran; Schneider, Ron; Zohar, Eyal; Nesher, Ofer

    2013-06-01

    For the past 15 years, Elbit Systems is developing time-resolved active laser-gated imaging (LGI) systems for various applications. Traditional LGI systems are based on high sensitive gated sensors, synchronized to pulsed laser sources. Elbit propriety multi-pulse per frame method, which is being implemented in LGI systems, improves significantly the imaging quality. A significant characteristic of the LGI is its ability to penetrate a disturbing media, such as rain, haze and some fog types. Current LGI systems are based on image intensifier (II) sensors, limiting the system in spectral response, image quality, reliability and cost. A novel propriety optical gating module was developed in Elbit, untying the dependency of LGI system on II. The optical gating module is not bounded to the radiance wavelength and positioned between the system optics and the sensor. This optical gating method supports the use of conventional solid state sensors. By selecting the appropriate solid state sensor, the new LGI systems can operate at any desired wavelength. In this paper we present the new gating method characteristics, performance and its advantages over the II gating method. The use of the gated imaging systems is described in a variety of applications, including results from latest field experiments.

  19. Evaluating image denoising methods in myocardial perfusion single photon emission computed tomography (SPECT) imaging

    International Nuclear Information System (INIS)

    The statistical nature of single photon emission computed tomography (SPECT) imaging, due to the Poisson noise effect, results in the degradation of image quality, especially in the case of lesions of low signal-to-noise ratio (SNR). A variety of well-established single-scale denoising methods applied on projection raw images have been incorporated in SPECT imaging applications, while multi-scale denoising methods with promising performance have been proposed. In this paper, a comparative evaluation study is performed between a multi-scale platelet denoising method and the well-established Butterworth filter applied as a pre- and post-processing step on images reconstructed without and/or with attenuation correction. Quantitative evaluation was carried out employing (i) a cardiac phantom containing two different size cold defects, utilized in two experiments conducted to simulate conditions without and with photon attenuation from myocardial surrounding tissue and (ii) a pilot-verified clinical dataset of 15 patients with ischemic defects. Image noise, defect contrast, SNR and defect contrast-to-noise ratio (CNR) metrics were computed for both phantom and patient defects. In addition, an observer preference study was carried out for the clinical dataset, based on rankings from two nuclear medicine clinicians. Without photon attenuation conditions, denoising by platelet and Butterworth post-processing methods outperformed Butterworth pre-processing for large size defects, while for small size defects, as well as with photon attenuation conditions, all methods have demonstrated similar denoising performance. Under both attenuation conditions, the platelet method showed improved performance with respect to defect contrast, SNR and defect CNR in the case of images reconstructed without attenuation correction, however not statistically significant (p > 0.05). Quantitative as well as preference results obtained from clinical data showed similar performance of the

  20. A systematic desaturation method for images from the Atmospheric Imaging Assembly in the Solar Dynamics Observatory.

    Science.gov (United States)

    Torre, Gabriele; Schwartz, Richard; Piana, Michele; Massone, Anna Maria; Benvenuto, Federico

    2016-05-01

    The fine spatial resolution of the SDO AIA CCD's is often destroyed by the charge in saturated pixels overflowing into a swath of neighboring cells during fast rising solar flares. Automated exposure control can only mitigate this issue to a degree and it has other deleterious effects. Our method addresses the desaturation problem for AIA images as an image reconstruction problem in which the information content of the diffraction fringes, generated by the interaction between the incoming radiation and the hardware of the spacecraft, is exploited to recover the true image intensities within the primary saturated core of the image. This methodology takes advantage of some well defined techniques like cross-correlation and the Expectation Maximization method to invert the direct relation between the diffraction fringes intensities and the true flux intensities. During this talk a complete overview on the structure of the method will be provided, besides some reliability tests obtained by its application against synthetic and real data.

  1. Ortho Image and DTM Generation with Intelligent Methods

    Science.gov (United States)

    Bagheri, H.; Sadeghian, S.

    2013-10-01

    Nowadays the artificial intelligent algorithms has considered in GIS and remote sensing. Genetic algorithm and artificial neural network are two intelligent methods that are used for optimizing of image processing programs such as edge extraction and etc. these algorithms are very useful for solving of complex program. In this paper, the ability and application of genetic algorithm and artificial neural network in geospatial production process like geometric modelling of satellite images for ortho photo generation and height interpolation in raster Digital Terrain Model production process is discussed. In first, the geometric potential of Ikonos-2 and Worldview-2 with rational functions, 2D & 3D polynomials were tested. Also comprehensive experiments have been carried out to evaluate the viability of the genetic algorithm for optimization of rational function, 2D & 3D polynomials. Considering the quality of Ground Control Points, the accuracy (RMSE) with genetic algorithm and 3D polynomials method for Ikonos-2 Geo image was 0.508 pixel sizes and the accuracy (RMSE) with GA algorithm and rational function method for Worldview-2 image was 0.930 pixel sizes. For more another optimization artificial intelligent methods, neural networks were used. With the use of perceptron network in Worldview-2 image, a result of 0.84 pixel sizes with 4 neurons in middle layer was gained. The final conclusion was that with artificial intelligent algorithms it is possible to optimize the existing models and have better results than usual ones. Finally the artificial intelligence methods, like genetic algorithms as well as neural networks, were examined on sample data for optimizing interpolation and for generating Digital Terrain Models. The results then were compared with existing conventional methods and it appeared that these methods have a high capacity in heights interpolation and that using these networks for interpolating and optimizing the weighting methods based on inverse

  2. Welcome to Journal of Angiogenesis Research

    Directory of Open Access Journals (Sweden)

    Slevin Mark

    2009-09-01

    Full Text Available Abstract Angiogenesis is the growth of new blood vessels and is a key process which occurs during both physiological and pathological disease processes. Knowledge of the mechanisms through which this process is initiated and maintained will have a significant impact on the treatment of these diseases. Pathological angiogenesis occurs in major diseases such as cancer, diabetic retinopathies, age-related macular degeneration and atherosclerosis. In other diseases such as stroke and myocardial infarction, insufficient or improper angiogenesis results in tissue loss and ultimately higher morbidity and mortality.

  3. Mechanical and Chemical Signaling in Angiogenesis

    CERN Document Server

    2013-01-01

    This volume of Studies in Mechanobiology, Tissue Engineering and Biomaterials describes the most recent advances in angiogenesis research at all biological length scales: molecular, cellular and tissue, in both in vivo and in vitro settings.  Angiogenesis experts from diverse fields including engineering, cell and developmental biology, and chemistry have contributed chapters which focus on the mechanical and chemical signals which affect and promote blood vessel growth. Specific emphasis is given to novel methodologies and biomaterials that have been developed and applied to angiogenesis research. 

  4. Beamforming and holography image formation methods: an analytic study.

    Science.gov (United States)

    Solimene, Raffaele; Cuccaro, Antonio; Ruvio, Giuseppe; Tapia, Daniel Flores; O'Halloran, Martin

    2016-04-18

    Beamforming and holographic imaging procedures are widely used in many applications such as radar sensing, sonar, and in the area of microwave medical imaging. Nevertheless, an analytical comparison of the methods has not been done. In this paper, the Point Spread Functions pertaining to the two methods are analytically determined. This allows a formal comparison of the two techniques, and to easily highlight how the performance depends on the configuration parameters, including frequency range, number of scatterers, and data discretization. It is demonstrated that the beamforming and holography basically achieve the same resolution but beamforming requires a cheaper (less sensors) configuration.. PMID:27137336

  5. Inhibitory effects of KXSOI on angiogenesis in vitro

    Institute of Scientific and Technical Information of China (English)

    Xue-yuOUYANG; Wen-jieWANG

    2004-01-01

    AIM: To evaluate the inhibitory effects of new compound KXS01 on angiogenesis. METHODS: Aortae from Wistar rats were cut into rings, embedded in a fibrin clot and cultured for 12 d in serum-free medium and the microvessels were counted. Human umbilical vein endothelial celIs(HUVEC) were cultured with or without VEGF165 for 72 h and cell proliferation was studied by

  6. An improved image sharpness assessment method based on contrast sensitivity

    Science.gov (United States)

    Zhang, Li; Tian, Yan; Yin, Yili

    2015-10-01

    An image sharpness assessment method based on the property of Contrast Sensitivity Function (CSF) was proposed to realize the sharpness assessment of unfocused image. Firstly, image was performed the two-dimensional Discrete Fourier Transform (DFT), and intermediate frequency coefficients and high frequency coefficients are divided into two parts respectively. Secondly the four parts were performed the inverse Discrete Fourier Transform (IDFT) to obtain subimages. Thirdly, using Range Function evaluates the four sub-image sharpness value. Finally, the image sharpness is obtained through the weighted sum of the sub-image sharpness value. In order to comply with the CSF characteristics, weighting factor is setting based on the Contrast Sensitivity Function. The new algorithm and four typical evaluation algorithm: Fourier, Range , Variance and Wavelet are evaluated based on the six quantitative evaluation index, which include the width of steep part of focusing curve, the ration of sharpness, the steepness, the variance of float part of focusing curve, the factor of local extreme and the sensitivity. On the other hand, the effect of noise, and image content on algorithm is analyzed in this paper. The experiment results show that the new algorithm has better performance of sensitivity, anti-nose than the four typical evaluation algorithms. The evaluation results are consistent with human visual characteristics.

  7. Suite of proposed imaging performance metrics and test methods for fire service thermal imaging cameras

    Science.gov (United States)

    Amon, Francine; Lock, Andrew; Bryner, Nelson

    2008-04-01

    The use of thermal imaging cameras (TIC) by the fire service is increasing as fire fighters become more aware of the value of these tools. The National Fire Protection Association (NFPA) is currently developing a consensus standard for design and performance requirements for TIC as used by the fire service. This standard will include performance requirements for TIC design robustness and image quality. The National Institute of Standards and Technology facilitates this process by providing recommendations for science-based performance metrics and test methods to the NFPA technical committee charged with the development of this standard. A suite of imaging performance metrics and test methods based on the harsh operating environment and limitations of use particular to the fire service has been proposed for inclusion in the standard. The performance metrics include large area contrast, effective temperature range, spatial resolution, nonuniformity, and thermal sensitivity. Test methods to measure TIC performance for these metrics are in various stages of development. An additional procedure, image recognition, has also been developed to facilitate the evaluation of TIC design robustness. The pass/fail criteria for each of these imaging performance metrics are derived from perception tests in which image contrast, brightness, noise, and spatial resolution are degraded to the point that users can no longer consistently perform tasks involving TIC due to poor image quality.

  8. Diagnosis method of cucumber downy mildew with NIR hyperspectral imaging

    Science.gov (United States)

    Tian, Youwen; Li, Tianlai; Zhang, Lin; Zhang, Xiaodong

    2011-11-01

    This study was carried out to develop a hyperspectral imaging system in the near infrared (NIR) region (900-1700 nm) to diagnose cucumber downy mildew. Hyperspectral images were acquired from each diseased cucumber leaf samples with downy mildew and then their spectral data were extracted. Spectral data were analyzed using principal component analysis (PCA) to reduce the high dimensionality of the data and for selecting some important wavelengths. Out of 256 wavelengths, only two wavelengths (1426 and 1626nm) of first PC were selected as the optimum wavelengths for the diagnosis of cucumber downy mildew. The data analysis showed that it is possible to diagnose cucumber downy mildew with few numbers of wavelengths on the basis of their statistical image features and histogram features. The results revealed the potentiality of NIR hyperspectral imaging as an objective and non-destructive method for the authentication and diagnosis of cucumber downy mildew.

  9. An image segmentation based method for iris feature extraction

    Institute of Scientific and Technical Information of China (English)

    XU Guang-zhu; ZHANG Zai-feng; MA Yi-de

    2008-01-01

    In this article, the local anomalistic blocks such ascrypts, furrows, and so on in the iris are initially used directly asiris features. A novel image segmentation method based onintersecting cortical model (ICM) neural network was introducedto segment these anomalistic blocks. First, the normalized irisimage was put into ICM neural network after enhancement.Second, the iris features were segmented out perfectly and wereoutput in binary image type by the ICM neural network. Finally,the fourth output pulse image produced by ICM neural networkwas chosen as the iris code for the convenience of real timeprocessing. To estimate the performance of the presentedmethod, an iris recognition platform was produced and theHamming Distance between two iris codes was computed tomeasure the dissimilarity between them. The experimentalresults in CASIA vl.0 and Bath iris image databases show thatthe proposed iris feature extraction algorithm has promisingpotential in iris recognition.

  10. Gold and silver nanoparticles conjugated with heparin derivative possess anti-angiogenesis properties

    International Nuclear Information System (INIS)

    Silver and gold nanoparticles display unique physical and biological properties that have been extensively studied for biological and medical applications. Typically, gold and silver nanoparticles are prepared by chemical reductants that utilize excess toxic reactants, which need to be removed for biological purposes. We utilized a clean method involving a single synthetic step to prepare metal nanoparticles for evaluating potential effects on angiogenesis modulation. These nanoparticles were prepared by reducing silver nitrate and gold chloride with diaminopyridinyl (DAP)-derivatized heparin (HP) polysaccharides. Both gold and silver nanoparticles reduced with DAPHP exhibited effective inhibition of basic fibroblast growth factor (FGF-2)-induced angiogenesis, with an enhanced anti-angiogenesis efficacy with the conjugation to DAPHP (P<0.01) as compared to glucose conjugation. These results suggest that DAPHP-reduced silver nanoparticles and gold nanoparticles have potential in pathological angiogenesis accelerated disorders such as cancer and inflammatory diseases.

  11. Dynamic MRI and tumor angiogenesis of breast cancer

    International Nuclear Information System (INIS)

    The purpose of this study was to clarify the mechanism underlying early enhanced MR images of breast cancer by dynamic MR imaging from the aspect of tumor angiogenesis. The images depicted by dynamic MR imaging of breast cancer were divided into the following two groups: a marginal strong enhancement (MSE) pattern and a variable pattern without marginal strong enhancement (non-MSE). Twenty patients with invasive ductal carcinoma (maximum diameter <2 cm) were examined by dynamic MR imaging, and the histological materials were submitted to two-dimensional computer image analysis with immunohistochemistry and histochemistry; morphological microvessel characteristics and microvessel density were examined; and the expression of vascular endothelial growth factor (VEGF) was investigated. In the MSE cases, vessel wall irregularity of capillaries and venules in the peripheral area adjacent to the tumor correlated (p<0.0001) with the enhancement pattern, and the total microvessel density (especially of arterioles with a maximum diameter less than 50 μm) of the peripheral area adjacent to the tumor was significantly higher than that of the tumor area. However, in the non-MSE cases, total microvessel density showed no significant difference between the peripheral area adjacent to the tumor and the tumor area, whereas the capillary density of the tumor area was four times greater than that of the peripheral area adjacent to the tumor. The expression of VEGF was strongly positive for the tumor nest adjacent to the capillaries. These results suggest that the enhanced images of the MSE pattern depend on abundant blood supply from arterioles and that the images of the non-MSE pattern might be reflective of angiogenic activity including variable VEGF expression of tumor cells. Thus the mechanism underlying early dynamic MR images of breast cancer was a complex result of tumor angiogenesis and the microcirculatory environment. (author)

  12. An Effective Method for Borehole Imaging of Buried Tunnels

    Directory of Open Access Journals (Sweden)

    Loreto Di Donato

    2012-01-01

    Full Text Available Detection and imaging of buried tunnels is a challenging problem which is relevant to both geophysical surveys and security monitoring. To comply with the need of exploring large portions of the underground, electromagnetic measurements carried out under a borehole configuration are usually exploited. Since this requires to drill holes in the soil wherein the transmitting and receiving antennas have to be positioned, low complexity of the involved apparatus is important. On the other hand, to effectively image the surveyed area, there is the need for adopting efficient and reliable imaging methods. To address these issues, in this paper we investigate the feasibility of the linear sampling method (LSM, as this inverse scattering method is capable to provide almost real-time results even when 3D images of very large domains are built, while not requiring approximations of the underlying physics. In particular, the results of the reported numerical analysis show that the LSM is capable of performing the required imaging task while using a quite simple measurement configuration consisting of two boreholes and a few number of multiview-multistatic acquisitions.

  13. Automatic intra-modality brain image registration method

    International Nuclear Information System (INIS)

    Full text: Registration of 3D images of brain of the same or different subjects has potential importance in clinical diagnosis, treatment planning and neurological research. The broad aim of our work is to produce an automatic and robust intra-modality, brain image registration algorithm for intra-subject and inter-subject studies. Our algorithm is composed of two stages. Initial alignment is achieved by finding the values of nine transformation parameters (representing translation, rotation and scale) that minimise the nonoverlapping regions of the head. This is achieved by minimisation of the sum of the exclusive OR of two binary head images, produced using the head extraction procedure described by Ardekani et al. (J Comput Assist Tomogr, 19:613-623, 1995). The initial alignment successfully determines the scale parameters and gross translation and rotation parameters. Fine alignment uses an objective function described for inter-modality registration in Ardekani et al. (ibid.). The algorithm segments one of the images to be aligned into a set of connected components using K-means clustering. Registration is achieved by minimising the K-means variance of the segmentation induced in the other image. Similarity of images of the same modality makes the method attractive for intra-modality registration. A 3D MR image, with voxel dimensions, 2x2x6 mm, was misaligned. The registered image shows visually accurate registration. The average displacement of a pixel from its correct location was measured to be 3.3 mm. The algorithm was tested on intra-subject MR images and was found to produce good qualitative results. Using the data available, the algorithm produced promising qualitative results in intra-subject registration. Further work is necessary in its application to intersubject registration, due to large variability in brain structure between subjects. Clinical evaluation of the algorithm for selected applications is required

  14. A Novel Multiresolution Fuzzy Segmentation Method on MR Image

    Institute of Scientific and Technical Information of China (English)

    ZHANG HongMei(张红梅); BIAN ZhengZhong(卞正中); YUAN ZeJian(袁泽剑); YE Min(叶敏); JI Feng(冀峰)

    2003-01-01

    Multiresolution-based magnetic resonance (MR) image segmentation has attractedattention for its ability to capture rich information across scales compared with the conventionalsegmentation methods. In this paper, a new scale-space-based segmentation model is presented,where both the intra-scale and inter-scale properties are considered and formulated as two fuzzyenergy functions. Meanwhile, a control parameter is introduced to adjust the contribution of thesimilarity character across scales and the clustering character within the scale. By minimizing thecombined inter/intra energy function, the multiresolution fuzzy segmentation algorithm is derived.Then the coarse to fine leading segmentation is performed automatically and iteratively on a set ofmultiresolution images. The validity of the proposed algorithm is demonstrated by the test imageand pathological MR images. Experiments show that by this approach the segmentation results,especially in the tumor area delineation, are more precise than those of the conventional fuzzy segmentation methods.

  15. Methods for gas detection using stationary hyperspectral imaging sensors

    Energy Technology Data Exchange (ETDEWEB)

    Conger, James L. (San Ramon, CA); Henderson, John R. (Castro Valley, CA)

    2012-04-24

    According to one embodiment, a method comprises producing a first hyperspectral imaging (HSI) data cube of a location at a first time using data from a HSI sensor; producing a second HSI data cube of the same location at a second time using data from the HSI sensor; subtracting on a pixel-by-pixel basis the second HSI data cube from the first HSI data cube to produce a raw difference cube; calibrating the raw difference cube to produce a calibrated raw difference cube; selecting at least one desired spectral band based on a gas of interest; producing a detection image based on the at least one selected spectral band and the calibrated raw difference cube; examining the detection image to determine presence of the gas of interest; and outputting a result of the examination. Other methods, systems, and computer program products for detecting the presence of a gas are also described.

  16. Methods for the Evaluation of Image Quality: A Review

    International Nuclear Information System (INIS)

    In medical imaging, information about the patient and possible abnormalities is transferred to the radiologist in two major steps: (i) data acquisition and image formation, and (ii) processing and display. Step one is mainly dependent on technical and physical characteristics of the equipment. Step two includes the vital importance of the performance of the radiologist; i.e. how he or she detects and interprets the structures in the image. The quality of a radiographical procedure must therefore be described with regard to both these steps. The spectrum of possible evaluation methods of importance will be described. The principles, benefits and drawbacks of some of these methods will be given together with examples of their use. (author)

  17. Imaging of intestinal fibrosis: current challenges and future methods.

    Science.gov (United States)

    Stidham, Ryan W; Higgins, Peter Dr

    2016-08-01

    Crohn's disease (CD) activity assessments are dominated by inflammatory changes without discrete measurement of the coexisting fibrotic contribution to total bowel damage. Intestinal fibrosis impacts the development of severe structural complications and the overall natural history of CD. Measuring intestinal fibrosis is challenging and existing methods of disease assessment are unable to reliably distinguish fibrosis from inflammation. Both the immediate clinical need to measure fibrosis for therapeutic decision-making and the near-future need for tools to assess pipeline anti-fibrotic medications highlight the demand for biomarkers of fibrosis in CD. Developing non-invasive technologies exploit changes in intestinal perfusion, mechanical properties, and macromolecular content to provide quantitative markers of fibrosis. In this review of existing and experimental technologies for imaging intestinal fibrosis, we discuss the expanding capabilities of quantitative MR and ultrasound imaging, encouraging developments in non-invasive elastography, and emerging novel methods including photoacoustic imaging. PMID:27536361

  18. Radiation Dose Reduction Methods For Use With Fluoroscopic Imaging, Computers And Implications For Image Quality

    Science.gov (United States)

    Edmonds, E. W.; Hynes, D. M.; Rowlands, J. A.; Toth, B. D.; Porter, A. J.

    1988-06-01

    The use of a beam splitting device for medical gastro-intestinal fluoroscopy has demonstrated that clinical images obtained with a 100mm photofluorographic camera, and a 1024 X 1024 digital matrix with pulsed progressive readout acquisition techniques, are identical. In addition, it has been found that clinical images can be obtained with digital systems at dose levels lower than those possible with film. The use of pulsed fluoroscopy with intermittent storage of the fluoroscopic image has also been demonstrated to reduce the fluoroscopy part of the examination to very low dose levels, particularly when low repetition rates of about 2 frames per second (fps) are used. The use of digital methods reduces the amount of radiation required and also the heat generated by the x-ray tube. Images can therefore be produced using a very small focal spot on the x-ray tube, which can produce further improvement in the resolution of the clinical images.

  19. Integrated in silico and experimental methods revealed that Arctigenin inhibited angiogenesis and HCT116 cell migration and invasion through regulating the H1F4A and Wnt/β-catenin pathway.

    Science.gov (United States)

    Zhang, Shouyue; Li, Jie; Song, Sicheng; Li, Jing; Tong, Rongsheng; Zang, Zhihe; Jiang, Qinglin; Cai, Lulu

    2015-11-01

    Arctigenin (ARG) has been previously reported to exert diverse biological activities including anti-proliferation, anti-inflammatory, and antiviral, etc. In the current study, the anti-metastasis and anti-angiogenesis activities of ARG were investigated. To further understand how ARG played these bioactivities, proteomic approaches were used to profile the proteome changes in response to ARG treatment using 2DE-MS/MS. Using these approaches, a total of 50 differentially expressed proteins were identified and clustered. Bioinformatics analysis suggested that multiple signalling pathways were involved. Moreover, ARG induced anti-metastatic and anti-angiogenesis activities were mainly accompanied by a deactivation of the Wnt/β-catenin pathway in HCT116 cells. PMID:26267229

  20. Integration of image exposure time into a modified laser speckle imaging method

    International Nuclear Information System (INIS)

    Speckle-based methods have been developed to characterize tissue blood flow and perfusion. One such method, called modified laser speckle imaging (mLSI), enables computation of blood flow maps with relatively high spatial resolution. Although it is known that the sensitivity and noise in LSI measurements depend on image exposure time, a fundamental disadvantage of mLSI is that it does not take into account this parameter. In this work, we integrate the exposure time into the mLSI method and provide experimental support of our approach with measurements from an in vitro flow phantom.

  1. An Efficient Image Enlargement Method for Image Sensors of Mobile in Embedded Systems

    Directory of Open Access Journals (Sweden)

    Hua Hua

    2016-01-01

    Full Text Available Main challenges for image enlargement methods in embedded systems come from the requirements of good performance, low computational cost, and low memory usage. This paper proposes an efficient image enlargement method which can meet these requirements in embedded system. Firstly, to improve the performance of enlargement methods, this method extracts different kind of features for different morphologies with different approaches. Then, various dictionaries based on different kind of features are learned, which represent the image in a more efficient manner. Secondly, to accelerate the enlargement speed and reduce the memory usage, this method divides the atoms of each dictionary into several clusters. For each cluster, separate projection matrix is calculated. This method reformulates the problem as a least squares regression. The high-resolution (HR images can be reconstructed based on a few projection matrixes. Numerous experiment results show that this method has advantages such as being efficient and real-time and having less memory cost. These advantages make this method easy to implement in mobile embedded system.

  2. Effect of VEGF, P53 and telomerase on angiogenesis of gastric carcinoma tissue

    Institute of Scientific and Technical Information of China (English)

    Yan-Fang Yu; Yong Zhang; Na Shen; Rui-Ying Zhang; Xin-Qing Lu

    2014-01-01

    Objective: To investigate the effect of vascular endothelial growth factor (VEGF), P53 and telomerase on angiogenesis in gastric carcinoma tissue. Methods: A total of 95 surgical resection samples of gastric cancer tissue after pathological diagnosis are collected to observe the VEGF, P53 and telomerase expression using immunohistochemical methods. Relationship between their expression and its influence on angiogenesis in gastric carcinoma tissue were analyzed. Results:Microvascular density (MVD) and the expression of VEGF, P53 and telomerase were positively correlated. Expression of VEGF and P53 protein were related to tumor type and lymph metastasis, and also a correlation was observed between P53 and VEGF. The telomerase expression had no correlation with VEGF, and P53. Conclusions: VEGF angiogenesis has a angiogenesis promoting effect on gastric cancer tissue development and plays an important role in tumor generation and metastasis. Mutant P53 promotes the tumor angiogenesis generation by adjusting VEGF. Telomerase has a certain role in promoting activity of angiogenesis through different way rather than P53.

  3. The ubiquitin-proteasome system meets angiogenesis.

    Science.gov (United States)

    Rahimi, Nader

    2012-03-01

    A strict physiological balance between endogenous proangiogenic and antiangiogenic factors controls endothelial cell functions, such that endothelial cell growth is normally restrained. However, in pathologic angiogenesis, a shift occurs in the balance of regulators, favoring endothelial growth. Much of the control of angiogenic events is instigated through hypoxia-induced VEGF expression. The ubiquitin-proteasome system (UPS) plays a central role in fine-tuning the functions of core proangiogenic proteins, including VEGF, VEGFR-2, angiogenic signaling proteins (e.g., the PLCγ1 and PI3 kinase/AKT pathways), and other non-VEGF angiogenic pathways. The emerging mechanisms by which ubiquitin modification of angiogenic proteins control angiogenesis involve both proteolytic and nonproteolytic functions. Here, I review recent advances that link the UPS to regulation of angiogenesis and highlight the potential therapeutic value of the UPS in angiogenesis-associated diseases. PMID:22357635

  4. Semaphorin signaling in angiogenesis, lymphangiogenesis and cancer

    Institute of Scientific and Technical Information of China (English)

    Atsuko Sakurai; Colleen Doci; J Silvio Gutkind

    2012-01-01

    Angiogenesis,the formation of new blood vessels from preexisting vasculature,is essential for many physiological processes,and aberrant angiogenesis contributes to some of the most prevalent human diseases,including cancer.Angiogenesis is controlled by delicate balance between pro- and anti-angiogenic signals.While pro-angiogenic signaling has been extensively investigated,how developmentally regulated,naturally occurring anti-angiogenic molecules prevent the excessive growth of vascular and lymphatic vessels is still poorly understood.In this review,we summarize the current knowledge on how semaphorins and their receptors,plexins and neuropilins,control normal and pathological angiogenesis,with an emphasis on semaphorin-regulated anti-angiogenic signaling circuitries in vascular and lymphatic endothelial cells.This emerging body of information may afford the opportunity to develop novel anti-angiogenic therapeutic strategies.

  5. Aberrant angiogenesis: The gateway to diabetic complications

    Directory of Open Access Journals (Sweden)

    Sunil K Kota

    2012-01-01

    Full Text Available Diabetes Mellitus is a metabolic cum vascular syndrome with resultant abnormalities in both micro- and macrovasculature. The adverse long-term effects of diabetes mellitus have been described to involve many organ systems. Apart from hyperglycemia, abnormalities of angiogenesis may cause or contribute toward many of the clinical manifestations of diabetes. These are implicated in the pathogenesis of vascular abnormalities of the retina, kidneys, and fetus, impaired wound healing, increased risk of rejection of transplanted organs, and impaired formation of coronary collaterals. A perplexing feature of the aberrant angiogenesis is that excessive and insufficient angiogenesis can occur in different organs in the same individual. The current article hereby reviews the molecular mechanisms including abnormalities in growth factors, cytokines, and metabolic derangements, clinical implications, and therapeutic options of dealing with abnormal angiogenesis in diabetes.

  6. Optimized optical clearing method for imaging central nervous system

    Science.gov (United States)

    Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan

    2015-03-01

    The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

  7. About Classification Methods Based on Tensor Modelling for Hyperspectral Images

    Directory of Open Access Journals (Sweden)

    Salah Bourennane

    2010-03-01

    Full Text Available Denoising and Dimensionality Reduction (DR are key issue to improve the classifiers efficiency for Hyper spectral images (HSI. The multi-way Wiener filtering recently developed is used, Principal and independent component analysis (PCA; ICA and projection pursuit(PP approaches to DR have been investigated. These matrix algebra methods are applied on vectorized images. Thereof, the spatial rearrangement is lost. To jointly take advantage of the spatial and spectral information, HSI has been recently represented as tensor. Offering multiple ways to decompose data orthogonally, we introduced filtering and DR methods based on multilinear algebra tools. The DR is performed on spectral way using PCA, or PP joint to an orthogonal projection onto a lower subspace dimension of the spatial ways. Weshow the classification improvement using the introduced methods in function to existing methods. This experiment is exemplified using real-world HYDICE data. Multi-way filtering, Dimensionality reduction, matrix and multilinear algebra tools, tensor processing.

  8. First-In-Human Study Demonstrating Tumor-Angiogenesis by PET/CT Imaging with 68Ga-NODAGA-THERANOST, a High-Affinity Peptidomimetic for αvβ3 Integrin Receptor Targeting

    Science.gov (United States)

    Baum, Richard P.; Kulkarni, Harshad R.; Müller, Dirk; Danthi, Narasimhan; Kim, Young-Seung; Brechbiel, Martin W.

    2015-01-01

    Abstract 68Ga-NODAGA-THERANOST™ is an αvβ3 integrin antagonist and the first radiolabeled peptidomimetic to reach clinical development for targeting integrin receptors. In this first-in-human study, the feasibility of integrin receptor peptidomimetic positron emission tomography/computed tomography (PET/CT) imaging was confirmed in patients with non-small-cell lung cancer and breast cancer. Methods: Patients underwent PET/CT imaging with 68Ga NODAGA-THERANOST. PET images were analyzed qualitatively and quantitatively and compared to 2-deoxy-2-(18F) fluoro-d-glucose (18F-FDG) findings. Images were obtained 60 minutes postinjection of 300–500 MBq of 68Ga-NODAGA-THERANOST. Results: 68Ga-NODAGA-THERANOST revealed high tumor-to-background ratios (SUVmax=4.8) and uptake at neoangiogenesis sites. Reconstructed fused images distinguished cancers with high malignancy potential and enabled enhanced bone metastasis detection. 18F-FDG-positive lung and lymph node metastases did not show uptake, indicating the absence of neovascularization. Conclusions: 68Ga-NODAGA-THERANOST was found to be safe and effective, exhibiting in this study rapid blood clearance, stability, rapid renal excretion, favorable biodistribution and PK/PD, low irradiation burden (μSv/MBq/μg), and convenient radiolabeling. This radioligand might enable theranostics, that is, a combination of diagnostics followed by the appropriate therapeutics, namely antiangiogenic therapy, image-guided presurgical assessment, treatment response evaluation, prediction of pathologic response, neoadjuvant-peptidomimetic-radiochemotherapy, and personalized medicine strategies. Further clinical trials evaluating 68Ga-NODAGA-THERANOST are warranted. PMID:25945808

  9. Caveolin-1 is important for nitric oxide-mediated angiogenesis in fibrin gels with human umbilical vein endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Yi-ming PAN; Yong-zhong YAO; Zhang-hua ZHU; Xi-tai SUN; Yu-dong QIU; Yi-tao DING

    2006-01-01

    Aim: The role of caveolin-l (Cav-1) in angiogenesis remains poorly understood. The endothelial nitric oxide (NO) synthase (eNOS), a caveolin-interacting protein, was demonstrated to play a predominant role in vascular endothelial growth factor (VEGF) -induced angiogenesis. The purpose of our study was to examine the role of Cav-1 and the eNOS complex in NO-mediated angiogenesis. Methods: Human umbilical vein endothelial cells (HUVEC) were isolated and cultured in 3-D fibrin gels to form capillary-like tubules by VEGF stimulation. The expression of Cav-1 and eNOS was detected by semiquantitative RT-PCR. The HUVEC were treated with antisense oligonucleotides to downregulate Cav-1 expression. Both transduced and non-infected HUVEC were cultured in fibrin gels in the presence or absence of VEGF (20 ng/mL) and NG-nitro-L-arginine methyl ester (L-NAME; 5 mmol/L). NO was measured using a NO assay kit and capillary-like tubules were quantified by tubule formation index using the Image J program. Results: RT-PCR analysis revealed that Cav-1 levels steadily increased in a time-dependent manner and reached their maximum after 5 d of incubation, but there were no obvious changes in eNOS mRNA expression in response to VEGF in the fibrin gel model. VEGF (20 ng/mL) can promote NO production and the formation of capillary-like tubules, and this promoting effect of VEGF was blocked by the addition of L-NAME (5 mmol/L). When transduced HUVEC with the antisense Cav-1 oligonucleotides were plated in the fibrin gels, the capillary-like tubules were significantly fewer than those of the non-infected cells. The capillary-like tubules formation and NO production of transduced HUVEC with the antisense Cav-1 oligonucleotides cultured in fibrin gels showed no responses to the addition of VEGF (20 ng/mL) and L-NAME (5.0 mmol/L). Conclusion: NO was a critical angiogenic mediator in this model. Cav-1 was essential for NO-mediated angiogenesis and may be an important target of anti-angiogenesis

  10. Angiomyolipomatosis of the kidney - possibilities and limitations of imaging methods

    Energy Technology Data Exchange (ETDEWEB)

    Schnepper, U.; Rieden, K.

    1989-02-01

    The authors report on a 31-year old female patient with recurrent renal colic since 1981 because of bilateral renal angiomyolipomas. The value of different diagnostic methods of imaging (ultrasonography, IVP, CT, angiography) with regard to the differential diagnosis and their probability of error are discussed. CT follow-up is recommended for all patients not subjected to surgical treatment.

  11. Gaussian Analytic Centroiding method of star image of star tracker

    Science.gov (United States)

    Wang, Haiyong; Xu, Ershuai; Li, Zhifeng; Li, Jingjin; Qin, Tianmu

    2015-11-01

    The energy distribution of an actual star image coincides with the Gaussian law statistically in most cases, so the optimized processing algorithm about star image centroiding should be constructed also by following Gaussian law. For a star image spot covering a certain number of pixels, the marginal distribution of the gray accumulation on rows and columns are shown and analyzed, based on which the formulas of Gaussian Analytic Centroiding method (GAC) are deduced, and the robustness is also promoted due to the inherited filtering effect of gray accumulation. Ideal reference star images are simulated by the PSF (point spread function) with integral form. Precision and speed tests for the Gaussian Analytic formulas are conducted under three scenarios of Gaussian radius (0.5, 0.671, 0.8 pixel), The simulation results show that the precision of GAC method is better than that of the other given algorithms when the Gaussian radius is not bigger than 5 × 5 pixel window, a widely used parameter. Above all, the algorithm which consumes the least time is still the novel GAC method. GAC method helps to promote the comprehensive performance in the attitude determination of a star tracker.

  12. Apparatus and method for velocity estimation in synthetic aperture imaging

    DEFF Research Database (Denmark)

    2003-01-01

    The invention relates to an apparatus for flow estimation using synthetic aperture imaging. The method uses a Synthetic Transmit Aperture, but unlike previous approaches a new frame is created after every pulse emission. In receive mode parallel beam forming is implemented. The beam formed RF data...

  13. Detection and monitoring of wear using imaging methods

    OpenAIRE

    Zhang, Jianbo

    2006-01-01

    Wear is traditionally measured offline. This thesis discusses a new methodology for online detection and monitoring of wear. The study comprises the design of an online wear testing apparatus and the development of techniques for online wear detection and monitoring using imaging methods.

  14. Electrodynamics, Differential Forms and the Method of Images

    Science.gov (United States)

    Low, Robert J.

    2011-01-01

    This paper gives a brief description of how Maxwell's equations are expressed in the language of differential forms and use this to provide an elegant demonstration of how the method of images (well known in electrostatics) also works for electrodynamics in the presence of an infinite plane conducting boundary. The paper should be accessible to an…

  15. Continuous Primal-Dual Methods for Image Processing

    CERN Document Server

    Goldman, Michael

    2010-01-01

    In this article we study a continuous Primal-Dual method proposed by Appleton and Talbot and generalize it to other problems in image processing. We interpret it as an Arrow-Hurwicz method which leads to a better description of the system of PDEs obtained. We show existence and uniqueness of solutions and get a convergence result for the denoising problem. Our analysis also yields new a posteriori estimates.

  16. Quantitative methods in phase-contrast x-ray imaging

    International Nuclear Information System (INIS)

    Full text: A new method for extracting quantitative information from phase-contrast x-ray images obtained with microfocus x-ray sources is presented. The proposed technique allows rapid non invasive characterization of the internal structure of thick optically opaque organic samples. The method does not generally involve any sample preparation and does not need any x-ray optical elements (such as monochromators, zone plates, or interferometers)

  17. Feature-Area Optimization: A Novel SAR Image Registration Method

    OpenAIRE

    Liu, Fuqiang; Bi, Fukun; Chen, Liang; Shi, Hao; Liu, Wei

    2016-01-01

    This letter proposes a synthetic aperture radar (SAR) image registration method named Feature-Area Optimization (FAO). First, the traditional area-based optimization model is reconstructed and decomposed into three key but uncertain factors: initialization, slice set and regularization. Next, structural features are extracted by scale invariant feature transform (SIFT) in dual-resolution space (SIFT-DRS), a novel SIFT-Like method dedicated to FAO. Then, the three key factors are determined ba...

  18. Polarimetric SAR Image Supervised Classification Method Integrating Eigenvalues

    OpenAIRE

    Xing Yanxiao; Zhang Yi; Li Ning; Wang Yu; Hu Guixiang

    2016-01-01

    Since classification methods based on H/α space have the drawback of yielding poor classification results for terrains with similar scattering features, in this study, we propose a polarimetric Synthetic Aperture Radar (SAR) image classification method based on eigenvalues. First, we extract eigenvalues and fit their distribution with an adaptive Gaussian mixture model. Then, using the naive Bayesian classifier, we obtain preliminary classification results. The distribution of eigenvalues in ...

  19. Spectral-Based Blind Image Restoration Method for Thin TOMBO Imagers

    Directory of Open Access Journals (Sweden)

    Farid Boussaid

    2008-09-01

    Full Text Available With the recent advances in microelectronic fabrication technology, it becomes now possible to fabricate thin imagers, less than half a millimeter thick. Dubbed TOMBO (an acronym for thin observation module by bound optics, a thin camera-on-a-chip integrates micro-optics and photo-sensing elements, together with advanced processing circuitry, all on a single silicon chip. Modeled after the compound-eye found in insects and many other arthropods, the TOMBO imager captures simultaneously a mosaic of low resolution images. In this paper, we describe and analyze a novel spectral-based blind algorithm that enables the restoration of a high resolution image from the captured low resolution images.The proposed blind restoration method does not require prior information about the imaging system nor the original scene. Furthermore, it alleviates the need for conventional de-shading and rearrangement processing techniques. Experimental results demonstrate that the proposed method can restore images for SNER lower than 3dB.

  20. Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method

    OpenAIRE

    2014-01-01

    Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM) images. However, as the number of the images inc...

  1. Method of automatic endocardium extraction from chest MRI images using three-dimensional digital image processing

    International Nuclear Information System (INIS)

    In this paper, we propose a method of endocardium extraction from chest MRI images. The proposed procedure constructed with three-dimentional digital image processing techniques is executed without manual intervention. A digital figure of endocardium is obtained as two components: left chambers and right chambers. The shape of extracted endocardium was verified by observing a voxel expression image displayed with depth-coded shading. Volume change curves of left and right chambers were calculated to show feasibility of using the results for measurement of cardiac functions. (author)

  2. Hyperspectral image-based methods for spectral diversity

    Science.gov (United States)

    Sotomayor, Alejandro; Medina, Ollantay; Chinea, J. D.; Manian, Vidya

    2015-05-01

    Hyperspectral images are an important tool to assess ecosystem biodiversity. To obtain more precise analysis of biodiversity indicators that agree with indicators obtained using field data, analysis of spectral diversity calculated from images have to be validated with field based diversity estimates. The plant species richness is one of the most important indicators of biodiversity. This indicator can be measured in hyperspectral images considering the Spectral Variation Hypothesis (SVH) which states that the spectral heterogeneity is related to spatial heterogeneity and thus to species richness. The goal of this research is to capture spectral heterogeneity from hyperspectral images for a terrestrial neo tropical forest site using Vector Quantization (VQ) method and then use the result for prediction of plant species richness. The results are compared with that of Hierarchical Agglomerative Clustering (HAC). The validation of the process index is done calculating the Pearson correlation coefficient between the Shannon entropy from actual field data and the Shannon entropy computed in the images. One of the advantages of developing more accurate analysis tools would be the extension of the analysis to larger zones. Multispectral image with a lower spatial resolution has been evaluated as a prospective tool for spectral diversity.

  3. Automatic ultrasonic image analysis method for defect detection

    International Nuclear Information System (INIS)

    Ultrasonic examination of austenitic steel weld seams raises well known problems of interpreting signals perturbed by this type of material. The JUKEBOX ultrasonic imaging system developed at the Cadarache Nuclear Research Center provides a major improvement in the general area of defect localization and characterization, based on processing overall images obtained by (X, Y) scanning. (X, time) images are formed by juxtaposing input signals. A series of parallel images shifted on the Y-axis is also available. The authors present a novel defect detection method based on analysing the timeline positions of the maxima and minima recorded on (X, time) images. This position is statistically stable when a defect is encountered, and is random enough under spurious noise conditions to constitute a discriminating parameter. The investigation involves calculating the trace variance: this parameters is then taken into account for detection purposes. Correlation with parallel images enhances detection reliability. A significant increase in the signal-to-noise ratio during tests on artificial defects is shown

  4. Influence of image reconstruction methods on statistical parametric mapping of brain PET images

    International Nuclear Information System (INIS)

    Objective: Statistic parametric mapping (SPM) was widely recognized as an useful tool in brain function study. The aim of this study was to investigate if imaging reconstruction algorithm of PET images could influence SPM of brain. Methods: PET imaging of whole brain was performed in six normal volunteers. Each volunteer had two scans with true and false acupuncturing. The PET scans were reconstructed using ordered subsets expectation maximization (OSEM) and filtered back projection (FBP) with 3 varied parameters respectively. The images were realigned, normalized and smoothed using SPM program. The difference between true and false acupuncture scans was tested using a matched pair t test at every voxel. Results: (1) SPM corrected multiple comparison (Pcorrecteduncorrected<0.001): SPM derived from the images with different reconstruction method were different. The largest difference, in number and position of the activated voxels, was noticed between FBP and OSEM re- construction algorithm. Conclusions: The method of PET image reconstruction could influence the results of SPM uncorrected multiple comparison. Attention should be paid when the conclusion was drawn using SPM uncorrected multiple comparison. (authors)

  5. The Hemostatic System and Angiogenesis in Malignancy

    Directory of Open Access Journals (Sweden)

    Marek Z. Wojtukiewicz

    2001-01-01

    Full Text Available Coagulopathy and angiogenesis are among the most consistent host responses associated with cancer. These two respective processes, hitherto viewed as distinct, may in fact be functionally inseparable as blood coagulation and fibrinolysis, in their own right, influence tumor angiogenesis and thereby contribute to malignant growth. In addition, tumor angiogenesis appears to be controlled through both standard and non-standard functions of such elements of the hemostatic system as tissue factor, thrombin, fibrin, plasminogen activators, plasminogen, and platelets. “Cryptic” domains can be released from hemostatic proteins through proteolytic cleavage, and act systemically as angiogenesis inhibitors (e.g., angiostatin, antiangiogenic antithrombin III aaATIII. Various components of the hemostatic system either promote or inhibit angiogenesis and likely act by changing the net angiogenic balance. However, their complex influences are far from being fully understood. Targeted pharmacological and/ or genetic inhibition of pro-angiogenic activities of the hemostatic system and exploitation of endogenous angiogenesis inhibitors of the angiostatin and aaATIII variety are under study as prospective anti-cancer treatments.

  6. Hyperspectral image compression using an online learning method

    Science.gov (United States)

    Ülkü, Ä.°rem; Töreyin, B. Uǧur

    2015-05-01

    A hyperspectral image compression method is proposed using an online dictionary learning approach. The online learning mechanism is aimed at utilizing least number of dictionary elements for each hyperspectral image under consideration. In order to meet this "sparsity constraint", basis pursuit algorithm is used. Hyperspectral imagery from AVIRIS datasets are used for testing purposes. Effects of non-zero dictionary elements on the compression performance are analyzed. Results indicate that, the proposed online dictionary learning algorithm may be utilized for higher data rates, as it performs better in terms of PSNR values, as compared with the state-of-the-art predictive lossy compression schemes.

  7. Image processing method for multicore fiber geometric parameters

    Science.gov (United States)

    Zhang, Chuanbiao; Ning, Tigang; Li, Jing; Li, Chao; Ma, Shaoshuo

    2016-05-01

    An image processing method has been developed to obtain multicore fiber geometric parameters. According to the characteristics of multicore fiber, we using MATLAB to processing the sectional view of the multicore fiber (MCF), and the algorithm mainly concludes the following steps: filter out image noise, edge detection, use an appropriate threshold for boundary extraction and an improved curve-fitting algorithm for reconstruction the cross section, then we get the relative geometric parameters of the MCF in pixels. We also compares different edge detection operator and analyzes each detection results, which can provide a meaningful reference for edge detection.

  8. Graphical Methods for Quantifying Macromolecules through Bright Field Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hang; DeFilippis, Rosa Anna; Tlsty, Thea D.; Parvin, Bahram

    2008-08-14

    Bright ?eld imaging of biological samples stained with antibodies and/or special stains provides a rapid protocol for visualizing various macromolecules. However, this method of sample staining and imaging is rarely employed for direct quantitative analysis due to variations in sample fixations, ambiguities introduced by color composition, and the limited dynamic range of imaging instruments. We demonstrate that, through the decomposition of color signals, staining can be scored on a cell-by-cell basis. We have applied our method to Flbroblasts grown from histologically normal breast tissue biopsies obtained from two distinct populations. Initially, nuclear regions are segmented through conversion of color images into gray scale, and detection of dark elliptic features. Subsequently, the strength of staining is quanti?ed by a color decomposition model that is optimized by a graph cut algorithm. In rare cases where nuclear signal is significantly altered as a result of samplepreparation, nuclear segmentation can be validated and corrected. Finally, segmented stained patterns are associated with each nuclear region following region-based tessellation. Compared to classical non-negative matrix factorization, proposed method (i) improves color decomposition, (ii) has a better noise immunity, (iii) is more invariant to initial conditions, and (iv) has a superior computing performance

  9. Image-based Water Level Measurement Method under Stained Ruler

    Institute of Scientific and Technical Information of China (English)

    Jae-do KIM; Young-joon HAN; Hern-soo HAHN

    2010-01-01

    This paper proposes the water level measuring method based on the image,while the ruler used to indicate the water level is stained.The contamination of the ruler weakens or eliminates many features which are required for the image processing.However,the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features.As the color differences are embossed,only the region of the ruler is limited to eliminate the noise,and the average image is produced by using several continuous frames.A histogram is then produced based on the height axis of the produced intensity average image.Local peaks and local valleys are detected,and the section between the peak and valley which have the greatest change is looked for.The valley point at this very moment is used to detect the water level.The detected water level is then converted to the actual water level by using the mapping table.The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.

  10. A Visually Inspired Variational Method for Automatic Image Registration

    Directory of Open Access Journals (Sweden)

    WANG Huixian

    2015-08-01

    Full Text Available A visually inspired variational method for automatic image registration is proposed to solve local deformation which traditional global registration model cannot well satisfy. The variational model considers local transformation, global smoothness and visual constraints. To account for intensity variations, we incorporate change of local contrast and brightness into our model. Firstly, the data entry of registration model is built according to the root-mean-square error of intensity; secondly, adaptive constraint using H1 half norm is used to ensure the global smooth in the model; finally, in order to make sure that the spatial attributes of the image satisfy the visual requirements and without distortion, the linear features are used as priori constraints. During the solution of model parameters, the whole image is used to globally estimate the transformation parameters, and then local estimation of the parameters is taken in a small neighbor. The entire procedure is built upon a multi-level differential framework, and the transformation parameters are calculated iteratively, which can consider both global smoothness and local distortion. To assess the quality of the proposed method, ZY-3 satellite images were used. Visual and quantitative analysis proved that the proposed method can significantly improve the registration precision.

  11. Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method

    Directory of Open Access Journals (Sweden)

    Ertan Öznergiz

    2014-01-01

    Full Text Available Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM images. However, as the number of the images increases, manual fiber diameter determination becomes a tedious and time consuming task as well as being sensitive to human errors. Therefore, an automated fiber diameter measurement system is desired. In the literature, this task is achieved by using image analysis algorithms. Typically, these methods first isolate each fiber in the image and measure the diameter of each isolated fiber. Fiber isolation is an error-prone process. In this study, automated calculation of nanofiber diameter is achieved without fiber isolation using image processing and analysis algorithms. Performance of the proposed method was tested on real data. The effectiveness of the proposed method is shown by comparing automatically and manually measured nanofiber diameter values.

  12. Closed crack growth monitoring using nonlinear ultrasonic imaging method

    International Nuclear Information System (INIS)

    It was necessary to clarify closing mechanism of closed fatigue crack and evaluate such in high precision so as to ensure reliability of nuclear reactor and airplane. Three dimensional crack growth monitoring of closed crack depth distribution in the length direction and change in open and closed region within a crack with crack extension was conducted for closed fatigue crack created at compact tension specimen made of aluminium alloy A 7075 using such developed methods of subharmonic phased array for crack evaluation (SPACE), imaging method for closed cracks using nonlinear response of elastic waves at subharmonic frequency, and also load difference phased array (LPDA), nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads. Results showed closed region within a crack was different in surface and inside and also open and closed region changed with crack extension in the three-dimensional way. (T. Tanaka)

  13. Image unsharpness: two methods to express image unsharpness in one value

    International Nuclear Information System (INIS)

    Two methods to express image unsharpness in one value are compared. The first method is commonly used and uses the noise-equivalent passband or its reciprocal value the equivalent blur (1/Ne) determined from the modulation transfer function (MTF). A radiographic image of a sharp edge is made and scanned by a microdensitometer and the film density is transferred into energy values with the use of the characteristic curve. After differentiation, a Fourier transform results in an MTF curve. A single value (Ne) substituting the complete MTF curve can be derived by integrating the squared MTF values over frequency. This noise-equivalent passband is expressed in 1p mm-1. 1/Ne is the equivalent blur (or sampling aperture) expressed in millimetres. The second method for determining the unsharpness derives a value from the energy-related edge response function, which will be called the equivalent unsharpness. Both methods use the same reference unsharpness, which indicates that the ''equivalent blur'' and the ''equivalent unsharpness'' are comparable values qualifying image unsharpness. Results of practical tests using both methods show that the values are practically the same. However, the second method is relatively simple and therefore an attractive tool for determining image unsharpness. (author)

  14. Ursolic acid-loaded chitosan nanoparticles induce potent anti-angiogenesis in tumor.

    Science.gov (United States)

    Jin, Hua; Pi, Jiang; Yang, Fen; Wu, Chaomin; Cheng, Xueli; Bai, Haihua; Huang, Dan; Jiang, Jinhuan; Cai, Jiye; Chen, Zheng W

    2016-08-01

    Angiogenesis provides necessary nutrients and oxygen for tumor growth and metastasis; thus, every stage of angiogenesis process is the potential target for cancer therapies. Ursolic acid (UA) is reported to decrease tumor burden through anti-angiogenesis pathway, but its poor water solubility greatly limits its efficiency and clinical application. Here, a simple method for preparing UA-loaded chitosan nanoparticles (CH-UA-NPs) with anti-angiogenesis and anti-tumor activity was demonstrated. In vitro, CH-UA-NPs could significantly inhibit the proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs). After uptake by HUVECs, CH-UA-NPs were mainly localized in lysosomes and mitochondria, but not nuclei. CH-UA-NPs induced the destruction of lysosome membrane integrity, collapse of mitochondrial membrane potential, and reorganization of cell cytoskeleton. All these changes led to the apoptosis or necrosis in HUVECs. In vivo, CH-UA-NPs could inhibit the angiogenesis in chicken chorioallantoic membrane (CAM) model and H22 xenograft model. Notably, comparing with free UA, such synthesized CH-UA-NPs could save about tenfold of UA doses, implying that this could significantly decrease the side effects induced by high doses of UA in biological organism. Our data showed that CH-UA-NPs and this nanoparticle-based drug delivery system could be as a potential drug candidate for anti-angiogenesis treatment. PMID:26883344

  15. Studies on angiogenesis and endothelial cell apoptosis in radiation-combined wound healing in Wistar rats

    International Nuclear Information System (INIS)

    Objective: To study the changes and significance of angiogenesis and endothelial cell apoptosis in radiation-combined wound healing. Methods: Wistar rats were wounded and then local irradiation was performed immediately with a dose of 25 Gy 60Co γ-rays in the irradiation wound group. Tissue specimens were obtained at 2, 5, 10, 15, 21 and 28 days after injury and angiogenesis and apoptosis of endothelial cells were investigated by means of LM, EM and in situ terminal labelling. Results: In the non-irradiation wound group, angiogenesis began from day 2 and the capillary number reached its peak on day 10 and decreased on day 15 after injury when the endothelial cells occurred apoptosis and scarcely necrosis. In the irradiation wound group angiogenesis began on day 5 when endothelial cells occurred apoptosis. The capillary number reached its peak on day 15 and decreased on day 21 after injury when endothelial cells occurred both apoptosis and necrosis. Conclusions: Radiation may delay the angiogenesis in wound healing, induce apoptosis of endothelial cells earlier and delay the peak of the capillary number. That radiation may delay the angiogenesis is one of reasons in delay of wound healing by radiation

  16. Spatial resolution properties of motion-compensated tomographic image reconstruction methods

    OpenAIRE

    Chun, Se Young; Fessler, Jeffrey A.

    2012-01-01

    Many motion-compensated image reconstruction (MCIR) methods have been proposed to correct for subject motion in medical imaging. MCIR methods incorporate motion models to improve image quality by reducing motion artifacts and noise.

  17. Erythropoietin blockade inhibits the induction of tumor angiogenesis and progression.

    Directory of Open Access Journals (Sweden)

    Matthew E Hardee

    Full Text Available BACKGROUND: The induction of tumor angiogenesis, a pathologic process critical for tumor progression, is mediated by multiple regulatory factors released by tumor and host cells. We investigated the role of the hematopoietic cytokine erythropoietin as an angiogenic factor that modulates tumor progression. METHODOLOGY/PRINCIPAL FINDINGS: Fluorescently-labeled rodent mammary carcinoma cells were injected into dorsal skin-fold window chambers in mice, an angiogenesis model that allows direct, non-invasive, serial visualization and real-time assessment of tumor cells and neovascularization simultaneously using intravital microscopy and computerized image analysis during the initial stages of tumorigenesis. Erythropoietin or its antagonist proteins were co-injected with tumor cells into window chambers. In vivo growth of cells engineered to stably express a constitutively active erythropoietin receptor EPOR-R129C or the erythropoietin antagonist R103A-EPO were analyzed in window chambers and in the mammary fat pads of athymic nude mice. Co-injection of erythropoietin with tumor cells or expression of EPOR-R129C in tumor cells significantly stimulated tumor neovascularization and growth in window chambers. Co-injection of erythropoietin antagonist proteins (soluble EPOR or anti-EPO antibody with tumor cells or stable expression of antagonist R103A-EPO protein secreted from tumor cells inhibited angiogenesis and impaired tumor growth. In orthotopic tumor xenograft studies, EPOR-R129C expression significantly promoted tumor growth associated with increased expression of Ki67 proliferation antigen, enhanced microvessel density, decreased tumor hypoxia, and increased phosphorylation of extracellular-regulated kinases ERK1/2. R103A-EPO antagonist expression in mammary carcinoma cells was associated with near-complete disruption of primary tumor formation in the mammary fat pad. CONCLUSIONS/SIGNIFICANCE: These data indicate that erythropoietin is an

  18. Methods, compositions and kits for imaging cells and tissues using nanoparticles and spatial frequency heterodyne imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rose-Petruck, Christoph; Wands, Jack R.; Rand, Danielle; Derdak, Zoltan; Ortiz, Vivian

    2016-04-19

    Methods, compositions, systems, devices and kits are provided herein for preparing and using a nanoparticle composition and spatial frequency heterodyne imaging for visualizing cells or tissues. In various embodiments, the nanoparticle composition includes at least one of: a nanoparticle, a polymer layer, and a binding agent, such that the polymer layer coats the nanoparticle and is for example a polyethylene glycol, a polyelectrolyte, an anionic polymer, or a cationic polymer, and such that the binding agent that specifically binds the cells or the tissue. Methods, compositions, systems, devices and kits are provided for identifying potential therapeutic agents in a model using the nanoparticle composition and spatial frequency heterodyne imaging.

  19. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    A novel method for obtaining cardiac images with X-rays is described. The problem of blurring of the image due to motion of the heart and its associated blood vessels is overcome by monitoring the cardiac cycle to produce a repeating pulse signal indicative of the same selectable phase; a pacemaker may be used to stabilize the cardiac period. Conventional CT scanning may then be performed and only the information recorded in coincidence with certain phases of the cardiac cycle is compounded to produce cardiac images which are free from blurring. Alternatively, the X-ray tube may be gated on and off by the pulse derived from the cardiac cycle in order to reduce X-ray dosage. (U.K.)

  20. Object Recognition Method of Space Debris Tracking Image Sequence

    Science.gov (United States)

    Zhang, C.; Ping, Y. D.

    2015-09-01

    In order to strengthen the capability of the space debris researches, automated optical observation becomes more and more popular. Thus, the fully unattended automated object recognition framework is urgently needed to be studied. On the other hand, the open loop tracking which guides the telescope only with historical orbital elements is a simple and robust way to track space debris. According to the analysis of point distribution characteristics in pixel domain of object's open loop tracking image sequence, the Cluster Identification Method is introduced into automated space debris recognition method. With the comparison of three algorithm implements, it is shown that this method is totally available in actual research work.

  1. Biomedical Image Processing with Morphology and Segmentation Methods for Medical Image Analysis

    Directory of Open Access Journals (Sweden)

    Joyjit Patra

    2013-07-01

    Full Text Available Modern three-dimensional (3-D medical imaging offers the potential and promise for major advances in science and medicine as higher fidelity images are produced.It has developed into one of the most important fields within scientific imaging due to the rapid and continuing progress in computerized medical image visualization and advances in analysis methods and computer-aided diagnosis[1],and is now,for example,a vital part of the early detection,diagnosis, and treatment of cancer.The challenge is to effectively process and analyze the images in order to effectively extract, quantify,and interpret this information to gain understanding and insight into the structure and function of the organs being imaged.The general goal is to understand the information and put it to practical use.A multitude of diagnostic medical imaging systems are used to probe the human body.They comprise both microscopic (viz. cellular level and macroscopic (viz.organ and systems level modalities.Interpretation of the resulting images requires sophisticated image processing methods that enhance visual interpretation and image analysis methods that provide automated or semiautomated tissue detection,measurement, and characterization [2–4].In general,multiple transformations will be needed in order to extract the data of interest from an image,and a hierarchy in the processing steps will be evident, e.g., enhancement will precede restoration,which will precede analysis,feature extraction,and classification[5].Often,these are performed sequentially, but more sophisticated tasks will require feedback of parameters to preceding steps so that the processing includes a number of iterative loops.Segmentation is one of the key tools in medical image analysis.The objective of segmentation is to provide reliable, fast, and effective organ delineation.While traditionally, particularly in computer vision, segmentation is seen as an early vision tool used for subsequent recognition

  2. Nonlinear optical methods for cellular imaging and localization.

    Science.gov (United States)

    McVey, A; Crain, J

    2014-07-01

    Of all the ways in which complex materials (including many biological systems) can be explored, imaging is perhaps the most powerful because delivering high information content directly. This is particular relevant in aspects of cellular localization where the physical proximity of molecules is crucial in biochemical processes. A great deal of effort in imaging has been spent on enabling chemically selective imaging so that only specific features are revealed. This is almost always achieved by adding fluorescent chemical labels to specific molecules. Under appropriate illumination conditions only the molecules (via their labels) will be visible. The technique is simple and elegant but does suffer from fundamental limitations: (1) the fluorescent labels may fade when illuminated (a phenomenon called photobleaching) thereby constantly decreasing signal contrast over the course of image acquisition. To combat photobleaching one must reduce observation times or apply unfavourably low excitation levels all of which reduce the information content of images; (2) the fluorescent species may be deactivated by various environmental factors (the general term is fluorescence quenching); (3) the presence of fluorescent labels may introduce unexpected complications or may interfere with processes of interest (4) Some molecules of interest cannot be labelled. In these circumstances we require a fundamentally different strategy. One of the most promising alternative is based on a technique called Coherent Anti-Stokes Raman scattering (CARS). CARS is a fundamentally more complex process than is fluorescence and the experimental procedures and optical systems required to deliver high quality CARS images are intricate. However, the rewards are correspondingly very high: CARS probes the chemically distinct vibrations of the constituent molecules in a complex system and is therefore also chemically selective as are fluorescence-based methods. Moreover,the potentially severe problems of

  3. Visualization of perfusion changes with laser speckle contrast imaging using the method of motion history image.

    Science.gov (United States)

    Ansari, Mohammad Zaheer; Humeau-Heurtier, Anne; Offenhauser, Nikolas; Dreier, Jens P; Nirala, Anil Kumar

    2016-09-01

    Laser speckle contrast imaging (LSCI) is a real-time imaging modality reflecting microvascular perfusion. We report on the application of the motion history image (MHI) method on LSCI data obtained from the two hemispheres of a mouse. Through the generation of a single image, MHI stresses the microvascular perfusion changes. Our experimental results performed during a pinprick-triggered spreading depolarization demonstrate the effectiveness of MHI: MHI allows the visualization of perfusion changes without loss of resolution and definition. Moreover, MHI provides close results to the ones given by the generalized differences (GD) algorithm. However, MHI has the advantage of giving information on the temporal evolution of the perfusion variations, which GD does not. PMID:27321386

  4. Bach1 Represses Wnt/β-Catenin Signaling and Angiogenesis

    Science.gov (United States)

    Liu, Junxu; Wang, Xinhong; Niu, Cong; Kang, Xueling; Xu, Jie; Zhou, Zhongwei; Sun, Shaoyang; Wang, Xu; Zheng, Xiaojun; Duan, Shengzhong; Yao, Kang; Qian, Ruizhe; Sun, Ning; Chen, Alex; Wang, Rui; Zhang, Jianyi; Chen, Sifeng; Meng, Dan

    2015-01-01

    Rationale Wnt/β-catenin signaling has an important role in the angiogenic activity of endothelial cells (ECs). Bach1 is a transcription factor and is expressed in ECs, but whether Bach1 regulates angiogenesis is unknown. Objective This study evaluated the role of Bach1 in angiogenesis and Wnt/β-catenin signaling. Methods and Results Hind-limb ischemia was surgically induced in Bach1−/− mice and their wild-type littermates and in C57BL/6J mice treated with adenoviruses coding for Bach1 or GFP. Lack of Bach1 expression was associated with significant increases in perfusion and vascular density and in the expression of proangiogenic cytokines in the ischemic hindlimb of mice, with enhancement of the angiogenic activity of ECs (eg, tube formation, migration, and proliferation). Bach1 overexpression impaired angiogenesis in mice with hind-limb ischemia and inhibited Wnt3a-stimulated angiogenic response and the expression of Wnt/β-catenin target genes, such as interleukin-8 and vascular endothelial growth factor, in human umbilical vein ECs. Interleukin-8 and vascular endothelial growth factor were responsible for the antiangiogenic response of Bach1. Immunoprecipitation and GST pull-down assessments indicated that Bach1 binds directly to TCF4 and reduces the interaction of β-catenin with TCF4. Bach1 overexpression reduces the interaction between p300/CBP and β-catenin, as well as β-catenin acetylation, and chromatin immunoprecipitation experiments confirmed that Bach1 occupies the TCF4-binding site of the interleukin-8 promoter and recruits histone deacetylase 1 to the interleukin-8 promoter in human umbilical vein ECs. Conclusions Bach1 suppresses angiogenesis after ischemic injury and impairs Wnt/β-catenin signaling by disrupting the interaction between β-catenin and TCF4 and by recruiting histone deacetylase 1 to the promoter of TCF4-targeted genes. PMID:26123998

  5. Dihydroartemisinin promotes angiogenesis during the early embryonic development of zebrafish

    Institute of Scientific and Technical Information of China (English)

    Qian BA; Juan DUAN; Jia-qiang TIAN; Zi-liang WANG; Tao CHEN; Xiao-guang LI; Pei-zhan CHEN

    2013-01-01

    Aim:To investigate the embryotoxicity of dihydroartemisinin (DHA),the main active metabolite of artemisinin,in zebrafish,and explore the corresponding mechanisms.Methods:The embryos of wild type and TG (flk1:GFP) transgenic zebrafish were exposed to DHA.Developmental phenotypes of the embryos were observed.Development of blood vessels was directly observed in living embryos of TG (flk1:GFP) transgenic zebrafish under fluorescence microscope.The expression of angiogenesis marker genes vegfa,flk1,and flt1 in the embryos was detected using real-time PCR and RNA in situ hybridization assays.Results:Exposure to DHA (1-10 mg/L) dose-dependently caused abnormal zebrafish embryonic phenotypes in the early developmental stage.Furthermore,exposure to DHA (10 mg/L) resulted in more pronounced embryonic angiogenesis in TG (flk1:GFP)zebrafish line.Exposure to DHA (10 mg/L) significantly increased the mRNA expression of vegfa,flk1,and flt1 in the embryos.Knockdown of the ilk1 protein partially blocked the effects of DHA on embryogenesis.Conclusion:DHA causes abnormal embryonic phenotypes and promotes angiogenesis in zebrafish early embryonic development,demonstrating the potential embryotoxicity of DHA.

  6. The Effect of Twist Expression on Angiogenesis in Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Gangmin Xi; Lin Zhang; Zhongli Zhan; Lihua Zhang; Xiyin Wei; Yi Yang; Yurong Shi; Fei Zhang; Ruifang Niu

    2006-01-01

    OBJECTIVE Hepatocellular carcinoma (HCC) is a hypervascular tumor for which angiogenesis plays an important role in its progression. The aim of this study was to investigate the expression of TWIST and VEGF and determine their roles in angiogenesis of HCC.METHODS Expression Twist and VEGF mRNA was determined by realtime RT-PCR in 30 pairs of hepatocellular carcinoma and matched noncancerous tissues. Immunohistochemistry was carried out to analyze the protein expression of Twist and VEGF in 40 hepatocellular carcinoma cases. Staining of endothelial cells for CD34 was used to evaluate the microvessel density (MVD).RESULTS We found that the HCC specimens showing positive Twist expression in tumor cells had a higher microvessel density than those without Twist expression. Furthermore, we found that overexpression of the Twist protein positively correlated with up-regulation of VEGF in the HCC tissues (r=0.479, P=0.002).CONCLUSION Our results demonstrate that Twist may play an important role in the angiogenesis of HCC and a high-level of Twist expression may be related to the malignant potential of tumor cells.

  7. Single Image Haze Removal Method for Inland River

    Directory of Open Access Journals (Sweden)

    Qiu Liu

    2013-01-01

    Full Text Available Due to environmental pollution, the climate is worsening. The fog days up to 60% of the year in inland certain segments, which it has seriously affected the marine electronic cruise normal operation and navigation safety. According to the inland video image becomes gray and lack of visibility in foggy weather conditions, and in order to remove the haze to get a clear image color and contour, this paper presents a method based on Jones Extension Matrix and the Dark Channel Prior. First, we obtain the light intensity in the atmosphere and the estimated concentration of the haze by using Dark Channel Prior, and via using the Jones Extension Matrix and the parameters of Stokes' Law to eliminate part of the scattered light. At last, we have completed the function of image dehazing by brightness adjustment factor based on N pixels in the field of step brightness and improve the brightness based on Retinex Principle for the recovered image. Experimental results show this algorithm improves scenery visual effect in condition of haze. It is provided a clear video image for the marine electronic cruise in the foggy day.

  8. A method of imaging viscoelastic parameters with acoustic radiation force

    International Nuclear Information System (INIS)

    Acoustic radiation force has been proposed as a method of interrogating the mechanical properties of tissue. One simple approach applies a series of focused ultrasonic pulses to generate an acoustic radiation force, then processes the echoes returned from these pulses to estimate the radiation-force-induced displacement as a function of time. This process can be repeated at a number of locations to acquire data for image formation. In previous work we have formed images of tissue stiffness by depicting the maximum displacement induced at each tissue location after a finite period of insonification. While these maximum displacement images are able to differentiate materials of disparate mechanical properties, they exploit only a fraction of the information available. In this paper we show that the time-displacement curves acquired from tissue mimicking phantoms exhibit a viscoelastic response which is accurately described by the Voigt model. We describe how the viscous and elastic parameters of this model may be determined from experimental data. Finally, we show phantom images that depict not only the maximum local displacement, but also the viscous and elastic model parameters. These images offer complementary information about the target. (author)

  9. Methods for spectral image analysis by exploiting spatial simplicity

    Science.gov (United States)

    Keenan, Michael R.

    2010-11-23

    Several full-spectrum imaging techniques have been introduced in recent years that promise to provide rapid and comprehensive chemical characterization of complex samples. One of the remaining obstacles to adopting these techniques for routine use is the difficulty of reducing the vast quantities of raw spectral data to meaningful chemical information. Multivariate factor analysis techniques, such as Principal Component Analysis and Alternating Least Squares-based Multivariate Curve Resolution, have proven effective for extracting the essential chemical information from high dimensional spectral image data sets into a limited number of components that describe the spectral characteristics and spatial distributions of the chemical species comprising the sample. There are many cases, however, in which those constraints are not effective and where alternative approaches may provide new analytical insights. For many cases of practical importance, imaged samples are "simple" in the sense that they consist of relatively discrete chemical phases. That is, at any given location, only one or a few of the chemical species comprising the entire sample have non-zero concentrations. The methods of spectral image analysis of the present invention exploit this simplicity in the spatial domain to make the resulting factor models more realistic. Therefore, more physically accurate and interpretable spectral and abundance components can be extracted from spectral images that have spatially simple structure.

  10. a Modified Method for Image Triangulation Using Inclined Angles

    Science.gov (United States)

    Alsadik, Bashar

    2016-06-01

    The ongoing technical improvements in photogrammetry, Geomatics, computer vision (CV), and robotics offer new possibilities for many applications requiring efficient acquisition of three-dimensional data. Image orientation is one of these important techniques in many applications like mapping, precise measurements, 3D modeling and navigation. Image orientation comprises three main techniques of resection, intersection (triangulation) and relative orientation, which are conventionally solved by collinearity equations or by using projection and fundamental matrices. However, different problems still exist in the state - of -the -art of image orientation because of the nonlinearity and the sensitivity to proper initialization and spatial distribution of the points. In this research, a modified method is presented to solve the triangulation problem using inclined angles derived from the measured image coordinates and based on spherical trigonometry rules and vector geometry. The developed procedure shows promising results compared to collinearity approach and to converge to the global minimum even when starting from far approximations. This is based on the strong geometric constraint offered by the inclined angles that are enclosed between the object points and the camera stations. Numerical evaluations with perspective and panoramic images are presented and compared with the conventional solution of collinearity equations. The results show the efficiency of the developed model and the convergence of the solution to global minimum even with improper starting values.

  11. A flower image retrieval method based on ROI feature

    Institute of Scientific and Technical Information of China (English)

    洪安祥; 陈刚; 李均利; 池哲儒; 张亶

    2004-01-01

    Flower image retrieval is a very important step for computer-aided plant species recognition. In this paper, we propose an efficient segmentation method based on color clustering and domain knowledge to extract flower regions from flower images. For flower retrieval, we use the color histogram of a flower region to characterize the color features of flower and two shape-based features sets, Centroid-Contour Distance (CCD) and Angle Code Histogram (ACH), to characterize the shape features of a flower contour. Experimental results showed that our flower region extraction method based on color clustering and domain knowledge can produce accurate flower regions. Flower retrieval results on a database of 885 flower images collected from 14 plant species showed that our Region-of-Interest (ROI) based retrieval approach using both color and shape features can perform better than a method based on the global color histogram proposed by Swain and Ballard (1991) and a method based on domain knowledge-driven segmentation and color names proposed by Das et al.(1999).

  12. A flower image retrieval method based on ROI feature

    Institute of Scientific and Technical Information of China (English)

    洪安祥; 陈刚; 李均利; 池哲儒; 张亶

    2004-01-01

    Flower image retrieval is a very important step for computer-aided plant species recognition.In this paper,we propose an efficient segmentation method based on color clustering and domain knowledge to extract flower regions from flower images.For flower retrieval,we use the color histogram of a flower region to characterize the color features of flower and two shape-based features sets,Centroid-Contour Distance(CCD)and Angle Code Histogram(ACH),to characterize the shape features of a flower contour.Experimental results showed that our flower region extraction method based on color clustering and domain knowledge can produce accurate flower regions.Flower retrieval results on a database of 885 flower images collected from 14 plant species showed that our Region-of-Interest(ROD based retrieval approach using both color and shape features can perform better than a method based on the global color histogram proposed by Swain and Ballard(1991)and a method based on domain knowledge-driven segmentation and color names proposed by Das et al.(1999).

  13. A method for dynamic subtraction MR imaging of the liver

    Directory of Open Access Journals (Sweden)

    Setti Ernesto

    2006-06-01

    Full Text Available Abstract Background Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. Methods Nineteen consecutive patients (median age 45 years; range 37–67 were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a rigid 3D translation using maximization of normalized mutual information (NMI, and (b fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. Results The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p t-test after non-rigid realignment. The overall average NMI increase was 31%. Conclusion This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions.

  14. High contrast optical imaging methods for image guided laser ablation of dental caries lesions

    Science.gov (United States)

    LaMantia, Nicole R.; Tom, Henry; Chan, Kenneth H.; Simon, Jacob C.; Darling, Cynthia L.; Fried, Daniel

    2014-02-01

    Laser based methods are well suited for automation and can be used to selectively remove dental caries to minimize the loss of healthy tissues and render the underlying enamel more resistant to acid dissolution. The purpose of this study was to determine which imaging methods are best suited for image-guided ablation of natural non-cavitated carious lesions on occlusal surfaces. Multiple caries imaging methods were compared including near-IR and visible reflectance and quantitative light fluorescence (QLF). In order for image-guided laser ablation to be feasible, chemical and physical modification of tooth surfaces due to laser irradiation cannot greatly reduce the contrast between sound and demineralized dental hard tissues. Sound and demineralized surfaces of 48 extracted human molar teeth with non-cavitated lesions were examined. Images were acquired before and after laser irradiation using visible and near-IR reflectance and QLF at several wavelengths. Polarization sensitive-optical coherence tomography was used to confirm that lesions were present. The highest contrast was attained at 1460-nm and 1500-1700-nm, wavelengths coincident with higher water absorption. The reflectance did not decrease significantly after laser irradiation for those wavelengths.

  15. Oscillation of Angiogenesis with Vascular Dropout in Diabetic Retinopathy by VESsel GENeration Analysis (VESGEN)

    Science.gov (United States)

    Parsons-Wingerter, Patricia; Radbakrishnan, Krisbnan; Vickerman, Mary B.; Kaiser, Peter K.

    2010-01-01

    PURPOSE. Vascular dropout and angiogenesis are hallmarks of the progression of diabetic retinopathy (DR). However, current evaluation of DR relies on grading of secondary vascular effects, such as microaneurysms and hemorrhages, by clinical examination instead of by evaluation of actual vascular changes. The purpose of this study was to map and quantify vascular changes during progression of DR by VESsel GENeration Analysis (VESGEN). METHODS. In this prospective cross-sectional study, 15 eyes with DR were evaluated with fluorescein angiography (FA) and color fundus photography, and were graded using modified Early Treatment Diabetic Retinopathy Study criteria. FA images were separated by semiautomatic image processing into arterial and venous trees. Vessel length density (L(sub v)), number density (N(sub v)), and diameter (D(sub v)) were analyzed in a masked fashion with VESGEN software. Each vascular tree was automatically segmented into branching generations (G(sub 1)...G(sub 8) or G(sub 9)) by vessel diameter and branching. Vascular remodeling status (VRS) for N(sub v) and L(sub v) was graded 1 to 4 for increasing severity of vascular change. RESULTS. By N(sub v) and L(sub v), VRS correlated significantly with the independent clinical diagnosis of mild to proliferative DR (13/15 eyes). N(sub v) and L(sub v) of smaller vessels (G(sub >=6) increased from VRS1 to VRS2 by 2.4 X and 1.6 X, decreased from VRS2 to VRS3 by 0.4 X and 0.6X, and increased from VRS3 to VRS4 by 1.7 X and 1.5 X (P angiogenesis/neovascularization and vascular dropout were dominated first by remodeling of arteries and subsequently by veins.

  16. 3D CT Imaging Method for Measuring Temporal Bone Aeration

    International Nuclear Information System (INIS)

    Objective: 3D volume reconstruction of CT images can be used to measure temporal bene aeration. This study evaluates the technique with respect to reproducibility and acquisition parameters. Material and methods: Helical CT images acquired from patients with radiographically normal temporal bones using standard clinical protocols were retrospectively analyzed. 3D image reconstruction was performed to measure the volume of air within the temporal bone. The appropriate threshold values for air were determined from reconstruction of a phantom with a known air volume imaged using the same clinical protocols. The appropriate air threshold values were applied to the clinical material. Results: Air volume was measured according to an acquisition algorithm. The average volume in the temporal bone CT group was 5.56 ml, compared to 5.19 ml in the head CT group (p = 0.59). The correlation coefficient between examiners was > 0.92. There was a wide range of aeration volumes among individual ears (0.76-18.84 ml); however, paired temporal bones differed by an average of just 1.11 ml. Conclusions: The method of volume measurement from 3D reconstruction reported here is widely available, easy to perform and produces consistent results among examiners. Application of the technique to archival CT data is possible using corrections for air segmentation thresholds according to acquisition parameters

  17. Non-contact capacitance based image sensing method and system

    Science.gov (United States)

    Novak, James L.; Wiczer, James J.

    1994-01-01

    A system and a method for imaging desired surfaces of a workpiece. A sensor having first and second sensing electrodes which are electrically isolated from the workpiece is positioned above and in proximity to the desired surfaces of the workpiece. An electric field is developed between the first and second sensing electrodes of the sensor in response to input signals being applied thereto and capacitance signals are developed which are indicative of any disturbances in the electric field as a result of the workpiece. An image signal of the workpiece may be developed by processing the capacitance signals. The image signals may provide necessary control information to a machining device for machining the desired surfaces of the workpiece in processes such as deburring or chamfering. Also, the method and system may be used to image dimensions of weld pools on a workpiece and surfaces of glass vials. The sensor may include first and second preview sensors used to determine the feed rate of a workpiece with respect to the machining device.

  18. Method and apparatus for animal positioning in imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Hadjioannou, Arion-Xenofon; Stout, David B.; Silverman, Robert W.

    2013-01-01

    An apparatus for imaging an animal includes a first mounting surface, a bed sized to support the animal and releasably secured to or integral with the first mounting surface. The apparatus also includes a plurality of straps, each having a first end in a fixed position relative to the bed and a second end for tightening around a limb of the animal. A method for in-vivo imaging of an animal includes providing an animal that has limbs, providing a first mounting surface, and providing a bed removably secured to or integral with the mounting surface and sized to support the animal as well as being coupled to a plurality of straps. The method also includes placing the animal on the bed between the plurality of straps and tightening at least two of the plurality of straps around at least two of the limbs such that the animal is substantially secured in place relative to the bed.

  19. Computer vision analysis of image motion by variational methods

    CERN Document Server

    Mitiche, Amar

    2014-01-01

    This book presents a unified view of image motion analysis under the variational framework. Variational methods, rooted in physics and mechanics, but appearing in many other domains, such as statistics, control, and computer vision, address a problem from an optimization standpoint, i.e., they formulate it as the optimization of an objective function or functional. The methods of image motion analysis described in this book use the calculus of variations to minimize (or maximize) an objective functional which transcribes all of the constraints that characterize the desired motion variables. The book addresses the four core subjects of motion analysis: Motion estimation, detection, tracking, and three-dimensional interpretation. Each topic is covered in a dedicated chapter. The presentation is prefaced by an introductory chapter which discusses the purpose of motion analysis. Further, a chapter is included which gives the basic tools and formulae related to curvature, Euler Lagrange equations, unconstrained de...

  20. High-resolution imaging methods in array signal processing

    DEFF Research Database (Denmark)

    Xenaki, Angeliki

    The purpose of this study is to develop methods in array signal processing which achieve accurate signal reconstruction from limited observations resulting in high-resolution imaging. The focus is on underwater acoustic applications and sonar signal processing both in active (transmit and receive...... in active sonar signal processing for detection and imaging of submerged oil contamination in sea water from a deep-water oil leak. The submerged oil _eld is modeled as a uid medium exhibiting spatial perturbations in the acoustic parameters from their mean ambient values which cause weak scattering......-of-arrival (DOA) of the associated wavefronts from a limited number of observations. Usually, there are only a few sources generating the acoustic wavefield such that DOA estimation is essentially a sparse signal reconstruction problem. Conventional methods for DOA estimation (i.e., beamforming) suffer from...

  1. Holographic Dual to Conical Defects III: Improved Image Method

    CERN Document Server

    Aref'eva, I Ya; Tikhanovskaya, M D

    2016-01-01

    The geodesics prescription in holographic approach in Lorentzian signature is valid only for geodesics which connect spacelike-separated points at the boundary, since there is no timelike geodesics which reach the boundary. There is also no straightforward analytic Euclidean continuation for a general background, such as e. g. moving particle in AdS. We propose an improved geodesic image method for two-point Lorentzian correlators which is valid for arbitrary time intervals in case of the bulk spacetime deformed by point particles. We illustrate that our prescription is consistent with the case when the analytic continuation exists and with the quasigeodesics prescription used in previous work. We also discuss some other applications of the improved image method, such as holographic entanglement entropy and multiple particles in AdS3.

  2. Mueller coherency matrix method for contrast image in tissue polarimetry

    Science.gov (United States)

    Arce-Diego, J. L.; Fanjul-Vélez, F.; Samperio-García, D.; Pereda-Cubián, D.

    2007-07-01

    In this work, we propose the use of the Mueller Coherency matrix of biological tissues in order to increase the information from tissue images and so their contrast. This method involves different Mueller Coherency matrix based parameters, like the eigenvalues analysis, the entropy factor calculation, polarization components crosstalks, linear and circular polarization degrees, hermiticity or the Quaternions analysis in case depolarisation properties of tissue are sufficiently low. All these parameters make information appear clearer and so increase image contrast, so pathologies like cancer could be detected in a sooner stage of development. The election will depend on the concrete pathological process under study. This Mueller Coherency matrix method can be applied to a single tissue point, or it can be combined with a tomographic technique, so as to obtain a 3D representation of polarization contrast parameters in pathological tissues. The application of this analysis to concrete diseases can lead to tissue burn depth estimation or cancer early detection.

  3. A method of complex background estimation in astronomical images

    CERN Document Server

    Popowicz, Adam

    2016-01-01

    In this paper, we present a novel approach to the estimation of strongly varying backgrounds in astronomical images by means of small objects removal and subsequent missing pixels interpolation. The method is based on the analysis of a pixel local neighborhood and utilizes the morphological distance transform. In contrast to popular background estimation techniques, our algorithm allows for accurate extraction of complex structures, like galaxies or nebulae. Moreover, it does not require multiple tuning parameters, since it relies on physical properties of CCD image sensors - the gain and the read-out noise characteristics. The comparison with other widely used background estimators revealed higher accuracy of the proposed technique. The superiority of the novel method is especially significant for the most challenging fluctuating backgrounds. The size of filtered out objects is tunable, therefore the algorithm may eliminate a wide range of foreground structures, including the dark current impulses, cosmic ra...

  4. Functional role of inorganic trace elements in angiogenesis part III: (Ti, Li, Ce, As, Hg, Va, Nb and Pb).

    Science.gov (United States)

    Saghiri, Mohammad Ali; Orangi, Jafar; Asatourian, Armen; Sorenson, Christine M; Sheibani, Nader

    2016-02-01

    Many essential elements exist in nature with significant influence on human health. Angiogenesis is vital in developmental, repair, and regenerative processes, and its aberrant regulation contributes to pathogenesis of many diseases including cancer. Thus, it is of great importance to explore the role of these elements in such a vital process. This is third in a series of reviews that serve as an overview of the role of inorganic elements in regulation of angiogenesis and vascular function. Here we will review the roles of titanium, lithium, cerium, arsenic, mercury, vanadium, niobium, and lead in these processes. The roles of other inorganic elements in angiogenesis were discussed in part I (N, Fe, Se, P, Au, and Ca) and part II (Cr, Si, Zn, Cu, and S) of these series. The methods of exposure, structure, mechanisms, and potential activities of these elements are briefly discussed. An electronic search was performed on the role of these elements in angiogenesis from January 2005 to April 2014. These elements can promote and/or inhibit angiogenesis through different mechanisms. The anti-angiogenic effect of titanium dioxide nanoparticles comes from the inhibition of angiogenic processes, and not from its toxicity. Lithium affects vasculogenesis but not angiogenesis. Nanoceria treatment inhibited tumor growth by inhibiting angiogenesis. Vanadium treatment inhibited cell proliferation and induced cytotoxic effects through interactions with DNA. The negative impact of mercury on endothelial cell migration and tube formation activities was dose and time dependent. Lead induced IL-8 production, which is known to promote tumor angiogenesis. Thus, understanding the impact of these elements on angiogenesis will help in development of new modalities to modulate angiogenesis under various conditions. PMID:26638864

  5. A Matrix Pencil Algorithm Based Multiband Iterative Fusion Imaging Method

    Science.gov (United States)

    Zou, Yong Qiang; Gao, Xun Zhang; Li, Xiang; Liu, Yong Xiang

    2016-01-01

    Multiband signal fusion technique is a practicable and efficient way to improve the range resolution of ISAR image. The classical fusion method estimates the poles of each subband signal by the root-MUSIC method, and some good results were get in several experiments. However, this method is fragile in noise for the proper poles could not easy to get in low signal to noise ratio (SNR). In order to eliminate the influence of noise, this paper propose a matrix pencil algorithm based method to estimate the multiband signal poles. And to deal with mutual incoherent between subband signals, the incoherent parameters (ICP) are predicted through the relation of corresponding poles of each subband. Then, an iterative algorithm which aimed to minimize the 2-norm of signal difference is introduced to reduce signal fusion error. Applications to simulate dada verify that the proposed method get better fusion results at low SNR.

  6. A PDE based Method for Speckle Reduction of Log-compressed Ultrasound Image

    Directory of Open Access Journals (Sweden)

    Jie Huang

    2011-04-01

    Full Text Available Speckle noise is widely existence in coherent imaging systems, such as synthetic aperture radar, sonar, ultrasound and laser imaging, and is commonly described as signal correlated. In this paper, we focus on speckle reduction problem in real ultrasound image. Unlike traditional anisotropic diffusion methods usually taking image gradient as a diffusion index, in this paper, we present a new texture based anisotropic diffusion method for speckle reduction in real ultrasound image. The results comparing our new method with other well known methods on both synthetic images and real ultrasound images are reported to show the superiority of our method in keeping important features of real ultrasound images.

  7. Development of a Method for Tissue Elasticity Imaging Using Tagged Magnetic Resonance Imaging

    CERN Document Server

    Takeuchi, Tomoki; Murase, Kenya

    2016-01-01

    The purpose of this study was to develop a method for tissue elasticity imaging using tagged magnetic resonance imaging (MRI). First, we developed a cyclic pressure device that used air to remotely transmit the power to generate cyclic deformation in an object. The pressure induced by the cyclic pressure device was measured by MRI-compatible force sensors. Second, we developed a software to calculate Young's modulus from tagged MRI data using the harmonic phase (HARP) method and the finite element method (FEM). We also developed a software to extract tag-cross points from tagged MRI data. Finally, we evaluated the usefulness of our method using three homogeneous silicone gel phantoms with different degrees of stiffness in comparison with Young's moduli measured by a material testing machine. The coefficient of variation of the pressure data measured by MRI-compatible force sensors was within 5 %, indicating that the reproducibility of the pressure generated by our cyclic pressure device was good. The Young's ...

  8. Study of ultrasound stiffness imaging methods using tissue mimicking phantoms.

    Science.gov (United States)

    Manickam, Kavitha; Machireddy, Ramasubba Reddy; Seshadri, Suresh

    2014-02-01

    A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm(-1)MHz(-1)) and (1.61 × 10(6) ± 0.127 to 1.76 × 10(6) ± 0.045 kg m(-2)s(-1)) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. PMID:24083832

  9. Criterial image preparation for a search method for digital watermarking image using correlation coefficient between pixel value histograms

    OpenAIRE

    Imamura, Kousuke; Kuroda, Hideo; Fujimura, Makoto

    2013-01-01

    An efficient two-stage image search method for the extraction of illegal copies on the Internet has been proposed in our previous paper. In the present paper, we propose a criterial image preparation method for more efficient searching in the pre-search stage. It is possible to accelerate searching without omission because the criterial image preparation method provides a criterial image set for the various attacks involving changes to known pixel values. In addition, we propose an improved p...

  10. Flow imaging method of electromagnetic measurement in well logging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Multiphase flow in an oil well is a dynamic phenomenon of inhomogeneous medium,which should be studied in a nonlinear way. This paper presents an electromagnetic measurement method based on the electrical property differences between oil,gas and water to scan,inverse and show the distribution and condition of multiphase flow. Both numerical simulation and physical experiments have proved that clear images could be obtained by this way.

  11. Refinement of thermal imager minimum resolvable temperature difference calculating method

    Science.gov (United States)

    Kolobrodov, V. G.; Mykytenko, V. I.

    2015-11-01

    Calculating methods, which accurately predict minimum resolvable temperature difference (MRTD), are of significant interest for many years. The article deals with improvement the accuracy of determining the thermal imaging system MRTD by elaboration the visual perception model. We suggest MRTD calculating algorithm, which is based on a reliable approximation of the human visual system modulation transfer function (MTF) proposed by N. Nill. There was obtained a new expression for the bandwidth evaluation, which is independent of angular size of the Foucault bar target.

  12. A method for dynamic subtraction MR imaging of the liver

    International Nuclear Information System (INIS)

    Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR) volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. Nineteen consecutive patients (median age 45 years; range 37–67) were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm) acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a) rigid 3D translation using maximization of normalized mutual information (NMI), and (b) fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test) and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p < 0.001, paired t-test) after non-rigid realignment. The overall average NMI increase was 31%. This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions

  13. Cancer gene therapy targeting angiogenesis: An updated review

    Institute of Scientific and Technical Information of China (English)

    Ching-Chiu Liu; Zan Shen; Hsiang-Fu Kung; Marie CM Lin

    2006-01-01

    Since the relationship between angiogenesis and tumor growth was established by Folkman in 1971,scientists have made efforts exploring the possibilities in treating cancer by targeting angiogenesis. Inhibition of angiogenesis growth factors and administration of angiogenesis inhibitors are the basics of antiangiogenesis therapy. Transfer of anti-angiogenesis genes has Received attention recently not only because of the advancement of recombinant vectors, but also because of the localized and sustained expression of therapeutic gene product inside the tumor after gene transfer. This review provides the up-to-date information about the strategies and the vectors studied in the field of anti-angiogenesis cancer gene therapy.

  14. Evaluating image reconstruction methods for tumor detection performance in whole-body PET oncology imaging

    Science.gov (United States)

    Lartizien, Carole; Kinahan, Paul E.; Comtat, Claude; Lin, Michael; Swensson, Richard G.; Trebossen, Regine; Bendriem, Bernard

    2000-04-01

    This work presents initial results from observer detection performance studies using the same volume visualization software tools that are used in clinical PET oncology imaging. Research into the FORE+OSEM and FORE+AWOSEM statistical image reconstruction methods tailored to whole- body 3D PET oncology imaging have indicated potential improvements in image SNR compared to currently used analytic reconstruction methods (FBP). To assess the resulting impact of these reconstruction methods on the performance of human observers in detecting and localizing tumors, we use a non- Monte Carlo technique to generate multiple statistically accurate realizations of 3D whole-body PET data, based on an extended MCAT phantom and with clinically realistic levels of statistical noise. For each realization, we add a fixed number of randomly located 1 cm diam. lesions whose contrast is varied among pre-calibrated values so that the range of true positive fractions is well sampled. The observer is told the number of tumors and, similar to the AFROC method, asked to localize all of them. The true positive fraction for the three algorithms (FBP, FORE+OSEM, FORE+AWOSEM) as a function of lesion contrast is calculated, although other protocols could be compared. A confidence level for each tumor is also recorded for incorporation into later AFROC analysis.

  15. Tumour angiogenesis-Origin of blood vessels.

    Science.gov (United States)

    Krishna Priya, S; Nagare, R P; Sneha, V S; Sidhanth, C; Bindhya, S; Manasa, P; Ganesan, T S

    2016-08-15

    The conventional view of tumour vascularization is that tumours acquire their blood supply from neighbouring normal stroma. Additional methods of tumour vascularization such as intussusceptive angiogenesis, vasculogenic mimicry, vessel co-option and vasculogenesis have been demonstrated to occur. However, the origin of the endothelial cells and pericytes in the tumour vasculature is not fully understood. Their origin from malignant cells has been shown indirectly in lymphoma and neuroblastoma by immuno-FISH experiments. It is now evident that tumours arise from a small population of cells called cancer stem cells (CSCs) or tumour initiating cells. Recent data suggest that a proportion of tumour endothelial cells arise from cancer stem cells in glioblastoma. This was demonstrated both in vitro and in vivo. The analysis of chromosomal abnormalities in endothelial cells showed identical genetic changes to those identified in tumour cells. However, another report contradicted these results from the earlier studies in glioblastoma and had shown that CSCs give rise to pericytes and not endothelial cells. The main thrust of this review is the critical analysis of the conflicting data from different studies and the remaining questions in this field of research. The mechanism by which this phenomenon occurs is also discussed in detail. The transdifferentiation of CSCs to endothelial cells/pericytes has many implications in the progression and metastasis of the tumours and hence it would be a novel target for antiangiogenic therapy. PMID:26934471

  16. VASCULAR REMODELING IN HYPERTENSION: ANGIOGENESIS FEATURES

    Directory of Open Access Journals (Sweden)

    L. A. Haisheva

    2014-07-01

    Full Text Available Aim — cross-sectional study of changes in various segments of the vascular bed in arterial hypertension (AH, defining the role of inducers and inhibitors of angiogenesis in these processes.Materials and methods. The study included 99 patients with arterial hypertension of I–II degree, average age of 63.2 ± 2.6 years, diseaseduration 9.2 ± 7.2 years.Results. It was found that patients with arterial hypertension have disorders in all segments of vascular bed: endothelial dysfunction (highvWF, microcirculatory disorders, and increased pulse wave velocity (PWV of elastic-type vessels. The level of angioginesis factors doesnot depend on such parameters as gender, age, body mass index. Smoking and duration of hypertension influence on vascular endothelialgrowth factor raise and endostatin levels are higher in patients with family history of cardiovascular diseases. Duration of disease is directlycorrelated with microcirculatory disorders and the PWV, correlation between microcirculatory disorders and pulse wave velocity indicatetheir common processes.

  17. A water-fat separation imaging method for the brain on low field magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Water-fat separation is a particularly important problem for magnetic resonance imaging.Although many methods have been proposed,the reliability is still challenging.In this work,we have presented a method based on the combination of the branch-cut method and multigrid algorithm to get a more robust performance of water-fat separation.First,the branch-cut method is applied to identify residues,which violates the requirement that the interacting phase gradient around a closed path be zero.Residues and branch...

  18. Soft-tissues Image Processing: Comparison of Traditional Segmentation Methods with 2D active Contour Methods

    Czech Academy of Sciences Publication Activity Database

    Mikulka, J.; Gescheidtová, E.; Bartušek, Karel

    2012-01-01

    Roč. 12, č. 4 (2012), s. 153-161. ISSN 1335-8871 R&D Projects: GA ČR GAP102/11/0318; GA ČR GAP102/12/1104; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Medical image processing * image segmentation * liver tumor * temporomandibular joint disc * watershed method Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.233, year: 2012

  19. Introduction of sensor spectral response into image fusion methods. Application to wavelet-based methods

    OpenAIRE

    Otazu Porter, Xavier; González-Audicana, María; Fors Aldrich, Octavi; Núñez de Murga, Jorge, 1955-

    2005-01-01

    Usual image fusion methods inject features from a high spatial resolution panchromatic sensor into every low spatial resolution multispectral band trying to preserve spectral signatures and improve spatial resolution to that of the panchromatic sensor. The objective is to obtain the image that would be observed by a sensor with the same spectral response (i.e., spectral sensitivity and quantum efficiency) as the multispectral sensors and the spatial resolution of the panchromatic sensor. But ...

  20. Discrete Method of Images for 3D Radio Propagation Modeling

    Science.gov (United States)

    Novak, Roman

    2016-09-01

    Discretization by rasterization is introduced into the method of images (MI) in the context of 3D deterministic radio propagation modeling as a way to exploit spatial coherence of electromagnetic propagation for fine-grained parallelism. Traditional algebraic treatment of bounding regions and surfaces is replaced by computer graphics rendering of 3D reflections and double refractions while building the image tree. The visibility of reception points and surfaces is also resolved by shader programs. The proposed rasterization is shown to be of comparable run time to that of the fundamentally parallel shooting and bouncing rays. The rasterization does not affect the signal evaluation backtracking step, thus preserving its advantage over the brute force ray-tracing methods in terms of accuracy. Moreover, the rendering resolution may be scaled back for a given level of scenario detail with only marginal impact on the image tree size. This allows selection of scene optimized execution parameters for faster execution, giving the method a competitive edge. The proposed variant of MI can be run on any GPU that supports real-time 3D graphics.