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Sample records for current noninvasive imaging

  1. Non-invasive imaging techniques in assessing non-alcoholic fatty liver disease: a current status of available methods.

    Science.gov (United States)

    Lăpădat, A M; Jianu, I R; Ungureanu, B S; Florescu, L M; Gheonea, D I; Sovaila, S; Gheonea, I A

    2017-01-01

    Non-alcoholic fatty liver disease (NAFLD) is an ailment affecting and increasing a number of people worldwide diagnosed via non-invasive imaging techniques, at a time when a minimum harm caused by medical procedures is rightfully emphasized, more sought after, than ever before. Liver steatosis should not be taken lightly even if its evolution is largely benign as it has the potential to develop into non-alcoholic steatohepatitis (NASH) or even more concerning, hepatic cirrhosis, and hepatocellular carcinoma (HCC). Traditionally, liver biopsy has been the standard for diagnosing this particular liver disease, but nowadays, a consistent number of imagistic methods are available for diagnosing hepatosteatosis and choosing the one appropriate to the clinical context is the key. Although different in sensitivity and specificity when it comes to determining the hepatic fat fraction (FF), these imaging techniques possessing a diverse availability, operating difficulty, cost, and reproducibility are invaluable to any modern physician. Ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), elastography, and spectroscopy will be discussed in order to lay out the advantages and disadvantages of their diagnostic potential and application. Although imagistics has given physicians a valuable insight into the means of managing NAFLD, the current methods are far from perfect, but given the time, they will surely be improved and the use of liver biopsy will be completely removed.

  2. Non-Invasive in vivo Imaging in Small Animal Research

    Directory of Open Access Journals (Sweden)

    V. Koo

    2006-01-01

    Full Text Available Non-invasive real time in vivo molecular imaging in small animal models has become the essential bridge between in vitro data and their translation into clinical applications. The tremendous development and technological progress, such as tumour modelling, monitoring of tumour growth and detection of metastasis, has facilitated translational drug development. This has added to our knowledge on carcinogenesis. The modalities that are commonly used include Magnetic Resonance Imaging (MRI, Computed Tomography (CT, Positron Emission Tomography (PET, bioluminescence imaging, fluorescence imaging and multi-modality imaging systems. The ability to obtain multiple images longitudinally provides reliable information whilst reducing animal numbers. As yet there is no one modality that is ideal for all experimental studies. This review outlines the instrumentation available together with corresponding applications reported in the literature with particular emphasis on cancer research. Advantages and limitations to current imaging technology are discussed and the issues concerning small animal care during imaging are highlighted.

  3. Imaging the pancreas: from ex vivo to non-invasive technology

    DEFF Research Database (Denmark)

    Holmberg, D; Ahlgren, U

    2008-01-01

    While many recently published reviews have covered non-invasive nuclear imaging techniques, the aim of this review is to focus on current developments in optical imaging technologies for investigating the pancreas. Several of these modalities are being developed into non-invasive, real...

  4. Noninvasive imaging technologies for cutaneous wound assessment: A review.

    Science.gov (United States)

    Paul, Dereck W; Ghassemi, Pejhman; Ramella-Roman, Jessica C; Prindeze, Nicholas J; Moffatt, Lauren T; Alkhalil, Abdulnaser; Shupp, Jeffrey W

    2015-01-01

    The ability to phenotype wounds for the purposes of assessing severity, healing potential and treatment is an important function of evidence-based medicine. A variety of optical technologies are currently in development for noninvasive wound assessment. To varying extents, these optical technologies have the potential to supplement traditional clinical wound evaluation and research, by providing detailed information regarding skin components imperceptible to visual inspection. These assessments are achieved through quantitative optical analysis of tissue characteristics including blood flow, collagen remodeling, hemoglobin content, inflammation, temperature, vascular structure, and water content. Technologies that have, to this date, been applied to wound assessment include: near infrared imaging, thermal imaging, optical coherence tomography, orthogonal polarization spectral imaging, fluorescence imaging, laser Doppler imaging, microscopy, spatial frequency domain imaging, photoacoustic detection, and spectral/hyperspectral imaging. We present a review of the technologies in use or development for these purposes with three aims: (1) providing basic explanations of imaging technology concepts, (2) reviewing the wound imaging literature, and (3) providing insight into areas for further application and exploration. Noninvasive imaging is a promising advancement in wound assessment and all technologies require further validation.

  5. Noninvasive imaging of oral premalignancy and malignancy

    Science.gov (United States)

    Wilder-Smith, Petra; Krasieva, T.; Jung, W.; You, J. S.; Chen, Z.; Osann, K.; Tromberg, B.

    2005-04-01

    Objectives: Early detection of cancer and its curable precursors remains the best way to ensure patient survival and quality of life. Despite significant advances in treatment, oral cancer still results in 10,000 U.S. deaths annually, mainly due to the late detection of most oral lesions. Specific aim was to use a combination of non-invasive optical in vivo technologies to test a multi-modality approach to non-invasive diagnostics of oral premalignancy and malignancy. Methods: In the hamster cheek pouch model (120 hamsters), in vivo optical coherence tomography (OCT) and optical Doppler tomography (ODT) mapped epithelial, subepithelial and vascular change throughout carcinogenesis in specific, marked sites. In vivo multi-wavelength multi-photon (MPM) and second harmonic generated (SHG) fluorescence techniques provided parallel data on surface and subsurface tissue structure, specifically collagen presence and structure, cellular presence, and vasculature. Images were diagnosed by 2 blinded, pre-standardized investigators using a standardized scale from 0-6 for all modalities. After sacrifice, histopathological sections were prepared and pathology evaluated on a scale of 0-6. ANOVA techniques compared imaging diagnostics with histopathology. 95% confidence limits of the sensitivity and specificity were established for the diagnostic capability of OCT/ODT+ MPM/SHG using ROC curves and kappa statistics. Results: Imaging data were reproducibly obtained with good accuracy. Carcinogenesis-related structural and vascular changes were clearly visible to tissue depths of 2mm. Sensitivity (OCT/ODT alone: 71-88%; OCT+MPM/SHG: 79-91%) and specificity (OCT alone: 62-83%;OCT+MPM/SHG: 67-90%) compared well with conventional techniques. Conclusions: OCT/ODT and MPM/SHG are promising non-invasive in vivo diagnostic modalities for oral dysplasia and malignancy. Supported by CRFA 30003, CCRP 00-01391V-20235, NIH (LAMMP) RR01192, DOE DE903-91ER 61227, NIH EB-00293 CA91717, NSF BES

  6. Non-invasive Imaging of Human Embryonic Stem Cells

    OpenAIRE

    Hong, Hao; Yang, Yunan; Zhang, Yin; Cai, Weibo

    2010-01-01

    Human embryonic stem cells (hESCs) hold tremendous therapeutic potential in a variety of diseases. Over the last decade, non-invasive imaging techniques have proven to be of great value in tracking transplanted hESCs. This review article will briefly summarize the various techniques used for non-invasive imaging of hESCs, which include magnetic resonance imaging (MRI), bioluminescence imaging (BLI), fluorescence, single-photon emission computed tomography (SPECT), positron emission tomography...

  7. Advances in noninvasive cardiovascular imaging: implications for the anesthesiologist.

    Science.gov (United States)

    Cahalan, M K; Litt, L; Botvinick, E H; Schiller, N B

    1987-03-01

    We have presented a review of recent advances in medical imaging which are relevant to the practice of anesthesia and associated research. The appropriate interpretation and use of the information derived from these noninvasive technologies can prevent unnecessary morbidity and mortality. Echocardiography remains the most advanced tool for noninvasive cardiac imaging because of its applicability for most cardiac disorders and its exquisite spatial resolution. Two-dimensional systems produce real time, dynamic, qualitative assessments of cardiac chamber morphology, size, thickness, and performance. The development of transesophageal echocardiography has brought this imaging power into the operating room for use by anesthesiologists. Recently developed quantitative and color-coded Doppler techniques will reveal intracardiac flow patterns and their alterations by anesthetics and surgery. These advantages are partially offset by inherent difficulties in quantifying echocardiographic data, and the need for highly trained operators for image reproduction. Nuclear cardiology and echocardiology are highly complementary. The scintigraphic methods identify myocardium at risk for infarction, confirm infarction when present, and produce quantitative, highly reproducible estimates of ventricular filling and performance. Time required to obtain data can be very brief for first-pass techniques, and these data are ideally suited for computer processing. Equilibrium studies require a larger dose of radioactive material, but provide excellent assessment of segmental wall motion. Preoperative studies with dipyridamole and Tl can indicate the patients truly at high risk for perioperative myocardial infarction. Monitoring and intensive care efforts may be better allocated with this information. No new technology in the past decade has stirred as much interest among clinicians as magnetic resonance imaging. Like echocardiography, it uses no ionizing radiation and is entirely noninvasive

  8. (19)F-heptuloses as tools for the non-invasive imaging of GLUT2-expressing cells

    DEFF Research Database (Denmark)

    Malaisse, Willy J; Zhang, Ying; Louchami, Karim

    2012-01-01

    Suitable analogs of d-mannoheptulose are currently considered as possible tools for the non-invasive imaging of pancreatic islet insulin-producing cells. Here, we examined whether (19)F-heptuloses could be used for non-invasive imaging of GLUT2-expressing cells. After 20 min incubation, the uptake...

  9. Non-invasive imaging of human embryonic stem cells.

    Science.gov (United States)

    Hong, Hao; Yang, Yunan; Zhang, Yin; Cai, Weibo

    2010-09-01

    Human embryonic stem cells (hESCs) hold tremendous therapeutic potential in a variety of diseases. Over the last decade, non-invasive imaging techniques have proven to be of great value in tracking transplanted hESCs. This review article will briefly summarize the various techniques used for non-invasive imaging of hESCs, which include magnetic resonance imaging (MRI), bioluminescence imaging (BLI), fluorescence, single-photon emission computed tomography (SPECT), positron emission tomography (PET), and multimodality approaches. Although the focus of this review article is primarily on hESCs, the labeling/tracking strategies described here can be readily applied to other (stem) cell types as well. Non-invasive imaging can provide convenient means to monitor hESC survival, proliferation, function, as well as overgrowth (such as teratoma formation), which could not be readily investigated previously. The requirement for hESC tracking techniques depends on the clinical scenario and each imaging technique will have its own niche in preclinical/clinical research. Continued evolvement of non-invasive imaging techniques will undoubtedly contribute to significant advances in understanding stem cell biology and mechanisms of action.

  10. MRI Reporter Genes for Noninvasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Caixia Yang

    2016-05-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most important imaging technologies used in clinical diagnosis. Reporter genes for MRI can be applied to accurately track the delivery of cell in cell therapy, evaluate the therapy effect of gene delivery, and monitor tissue/cell-specific microenvironments. Commonly used reporter genes for MRI usually include genes encoding the enzyme (e.g., tyrosinase and β-galactosidase, the receptor on the cells (e.g., transferrin receptor, and endogenous reporter genes (e.g., ferritin reporter gene. However, low sensitivity limits the application of MRI and reporter gene-based multimodal imaging strategies are common including optical imaging and radionuclide imaging. These can significantly improve diagnostic efficiency and accelerate the development of new therapies.

  11. Non-invasive imaging in detecting myocardial viability: Myocardial function versus perfusion

    Directory of Open Access Journals (Sweden)

    Iqbal A. Elfigih

    2014-12-01

    Full Text Available Coronary artery disease (CAD is the most prevalent and single most common cause of morbidity and mortality [1] with the resulting left ventricular (LV dysfunction an important complication. The distinction between viable and non-viable myocardium in patients with LV dysfunction is a clinically important issue among possible candidates for myocardial revascularization. Several available non-invasive techniques are used to detect and assess ischemia and myocardial viability. These techniques include echocardiography, radionuclide images, cardiac magnetic resonance imaging and recently myocardial computed tomography perfusion imaging. This review aims to distinguish between the available non-invasive imaging techniques in detecting signs of functional and perfusion viability and identify those which have the most clinical relevance in detecting myocardial viability in patients with CAD and chronic ischemic LV dysfunction. The most current available studies showed that both myocardial perfusion and function based on non-invasive imaging have high sensitivity with however wide range of specificity for detecting myocardial viability. Both perfusion and function imaging modalities provide complementary information about myocardial viability and no optimum single imaging technique exists that can provide very accurate diagnostic and prognostic viability assessment. The weight of the body of evidence suggested that non-invasive imaging can help in guiding therapeutic decision making in patients with LV dysfunction.

  12. Noninvasive bioluminescence imaging in small animals.

    Science.gov (United States)

    Zinn, Kurt R; Chaudhuri, Tandra R; Szafran, April Adams; O'Quinn, Darrell; Weaver, Casey; Dugger, Kari; Lamar, Dale; Kesterson, Robert A; Wang, Xiangdong; Frank, Stuart J

    2008-01-01

    There has been a rapid growth of bioluminescence imaging applications in small animal models in recent years, propelled by the availability of instruments, analysis software, reagents, and creative approaches to apply the technology in molecular imaging. Advantages include the sensitivity of the technique as well as its efficiency, relatively low cost, and versatility. Bioluminescence imaging is accomplished by sensitive detection of light emitted following chemical reaction of the luciferase enzyme with its substrate. Most imaging systems provide 2-dimensional (2D) information in rodents, showing the locations and intensity of light emitted from the animal in pseudo-color scaling. A 3-dimensional (3D) capability for bioluminescence imaging is now available, but is more expensive and less efficient; other disadvantages include the requirement for genetically encoded luciferase, the injection of the substrate to enable light emission, and the dependence of light signal on tissue depth. All of these problems make it unlikely that the method will be extended to human studies. However, in small animal models, bioluminescence imaging is now routinely applied to serially detect the location and burden of xenografted tumors, or identify and measure the number of immune or stem cells after an adoptive transfer. Bioluminescence imaging also makes it possible to track the relative amounts and locations of bacteria, viruses, and other pathogens over time. Specialized applications of bioluminescence also follow tissue-specific luciferase expression in transgenic mice, and monitor biological processes such as signaling or protein interactions in real time. In summary, bioluminescence imaging has become an important component of biomedical research that will continue in the future.

  13. Muscle perfusion and metabolic heterogeneity: insights from noninvasive imaging techniques

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Scheede-Bergdahl, Celena; Kjaer, Michael

    2006-01-01

    Recent developments in noninvasive imaging techniques have enabled the study of local changes in perfusion and metabolism in skeletal muscle as well as patterns of heterogeneity in these variables in humans. In this review, the principles of these techniques along with some recent findings on fun...

  14. Non-invasive terahertz field imaging inside parallel plate waveguides

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Andryieuski, Andrei; Lavrinenko, Andrei

    2011-01-01

    We present a non-invasive broadband air photonic method of imaging of the electric field of THz pulses propagating inside a tapered parallel plate waveguide. The method is based on field-enhanced second harmonic generation of the fundamental laser beam in an external electric field. We apply...

  15. Preclinical Evaluation of Photoacoustic Imaging as a Novel Noninvasive Approach to Detect an Orthopaedic Implant Infection

    NARCIS (Netherlands)

    Wang, Yu; Thompson, John M; Ashbaugh, Alyssa G; Khodakivskyi, Pavlo; Budin, Ghyslain; Sinisi, Riccardo; Heinmiller, Andrew; van Oosten, Marleen; van Dijl, Jan M; van Dam, Gooitzen M; Francis, Kevin P; Bernthal, Nicholas M; Dubikovskaya, Elena A; Miller, Lloyd S

    2016-01-01

    INTRODUCTION: Diagnosing prosthetic joint infection (PJI) poses significant challenges, and current modalities are fraught with low sensitivity and/or potential morbidity. Photoacoustic imaging (PAI) is a novel ultrasound-based modality with potential for diagnosing PJI safely and noninvasively. MAT

  16. Noninvasive Imaging of Administered Progenitor Cells

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    Steven R Bergmann, M.D., Ph.D.

    2012-12-03

    The objective of this research grant was to develop an approach for labeling progenitor cells, specifically those that we had identified as being able to replace ischemic heart cells, so that the distribution could be followed non-invasively. In addition, the research was aimed at determining whether administration of progenitor cells resulted in improved myocardial perfusion and function. The efficiency and toxicity of radiolabeling of progenitor cells was to be evaluated. For the proposed clinical protocol, subjects with end-stage ischemic coronary artery disease were to undergo a screening cardiac positron emission tomography (PET) scan using N-13 ammonia to delineate myocardial perfusion and function. If they qualified based on their PET scan, they would undergo an in-hospital protocol whereby CD34+ cells were stimulated by the administration of granulocytes-colony stimulating factor (G-CSF). CD34+ cells would then be isolated by apharesis, and labeled with indium-111 oxine. Cells were to be re-infused and subjects were to undergo single photon emission computed tomography (SPECT) scanning to evaluate uptake and distribution of labeled progenitor cells. Three months after administration of progenitor cells, a cardiac PET scan was to be repeated to evaluate changes in myocardial perfusion and/or function. Indium oxine is a radiopharmaceutical for labeling of autologous lymphocytes. Indium-111 (In-111) decays by electron capture with a t{sub ½} of 67.2 hours (2.8 days). Indium forms a saturated complex that is neutral, lipid soluble, and permeates the cell membrane. Within the cell, the indium-oxyquinolone complex labels via indium intracellular chelation. Following leukocyte labeling, ~77% of the In-111 is incorporated in the cell pellet. The presence of red cells and /or plasma reduces the labeling efficacy. Therefore, the product needed to be washed to eliminate plasma proteins. This repeated washing can damage cells. The CD34 selected product was a 90

  17. Multimodality Noninvasive Imaging in the Monitoring of Pediatric Heart Transplantation.

    Science.gov (United States)

    Kindel, Steven J; Hsu, Hao H; Hussain, Tarique; Johnson, Jonathan N; McMahon, Colin J; Kutty, Shelby

    2017-09-01

    Orthotopic heart transplantation is a well-established and effective therapeutic option for children with end-stage heart failure. Multiple modalities, including noninvasive cardiac imaging, cardiac catheterization, angiography, and endomyocardial biopsy, are helpful to monitor these patients for graft dysfunction, rejection, and vasculopathy. Because of morbidities associated with invasive monitoring, noninvasive imaging plays a key role in the surveillance and evaluation of symptoms in pediatric transplant recipients. Echocardiography with or without stress augmentation may provide serial data on systolic and diastolic function, ventricular deformation, and tissue characteristics in children after transplantation. Although not perfectly sensitive or specific, advanced two- and three-dimensional echocardiographic detection of functional changes in cardiac grafts may allow early recognition of allograft rejection. Magnetic resonance imaging has shown promise for characterization of edema and scar and myocardial perfusion reserve, as well as potential application for the detection of microvasculopathic changes in the transplanted heart. Cardiac computed tomography is particularly well suited for the demonstration of coronary artery dimensions and anatomic residual lesions. In combination, these noninvasive imaging techniques help the transplantation cardiologist screen for graft dysfunction, detect critical graft events, and identify situations that require invasive testing of the transplanted heart. Advanced multimodality imaging techniques are likely to increasingly shape the monitoring practices for children following heart transplantation. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  18. Assessment of disease activity in muscular dystrophies by noninvasive imaging.

    Science.gov (United States)

    Maguire, Katie K; Lim, Leland; Speedy, Sedona; Rando, Thomas A

    2013-05-01

    Muscular dystrophies are a class of disorders that cause progressive muscle wasting. A major hurdle for discovering treatments for the muscular dystrophies is a lack of reliable assays to monitor disease progression in animal models. We have developed a novel mouse model to assess disease activity noninvasively in mice with muscular dystrophies. These mice express an inducible luciferase reporter gene in muscle stem cells. In dystrophic mice, muscle stem cells activate and proliferate in response to muscle degeneration, resulting in an increase in the level of luciferase expression, which can be monitored by noninvasive, bioluminescence imaging. We applied this noninvasive imaging to assess disease activity in a mouse model of the human disease limb girdle muscular dystrophy 2B (LGMD2B), caused by a mutation in the dysferlin gene. We monitored the natural history and disease progression in these dysferlin-deficient mice up to 18 months of age and were able to detect disease activity prior to the appearance of any overt disease manifestation by histopathological analyses. Disease activity was reflected by changes in luciferase activity over time, and disease burden was reflected by cumulative luciferase activity, which paralleled disease progression as determined by histopathological analysis. The ability to monitor disease activity noninvasively in mouse models of muscular dystrophy will be invaluable for the assessment of disease progression and the effectiveness of therapeutic interventions.

  19. Non-invasive assessment of the liver using imaging

    Science.gov (United States)

    Thorling Thompson, Camilla; Wang, Haolu; Liu, Xin; Liang, Xiaowen; Crawford, Darrell H.; Roberts, Michael S.

    2016-12-01

    Chronic liver disease causes 2,000 deaths in Australia per year and early diagnosis is crucial to avoid progression to cirrhosis and end stage liver disease. There is no ideal method to evaluate liver function. Blood tests and liver biopsies provide spot examinations and are unable to track changes in function quickly. Therefore better techniques are needed. Non-invasive imaging has the potential to extract increased information over a large sampling area, continuously tracking dynamic changes in liver function. This project aimed to study the ability of three imaging techniques, multiphoton and fluorescence lifetime imaging microscopy, infrared thermography and photoacoustic imaging, in measuring liver function. Collagen deposition was obvious in multiphoton and fluorescence lifetime imaging in fibrosis and cirrhosis and comparable to conventional histology. Infrared thermography revealed a significantly increased liver temperature in hepatocellular carcinoma. In addition, multiphoton and fluorescence lifetime imaging and photoacoustic imaging could both track uptake and excretion of indocyanine green in rat liver. These results prove that non-invasive imaging can extract crucial information about the liver continuously over time and has the potential to be translated into clinic in the assessment of liver disease.

  20. Non-invasive diagnostic imaging of colorectal liver metastases

    Institute of Scientific and Technical Information of China (English)

    Pier; Paolo; Mainenti; Federica; Romano; Laura; Pizzuti; Sabrina; Segreto; Giovanni; Storto; Lorenzo; Mannelli; Massimo; Imbriaco; Luigi; Camera; Simone; Maurea

    2015-01-01

    Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases(CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liverdirected therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs.

  1. Non-invasive diagnostic imaging of colorectal liver metastases.

    Science.gov (United States)

    Mainenti, Pier Paolo; Romano, Federica; Pizzuti, Laura; Segreto, Sabrina; Storto, Giovanni; Mannelli, Lorenzo; Imbriaco, Massimo; Camera, Luigi; Maurea, Simone

    2015-07-28

    Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases (CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liver-directed therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs.

  2. Non-invasive imaging of microcirculation: a technology review

    Directory of Open Access Journals (Sweden)

    Eriksson S

    2014-12-01

    Full Text Available Sam Eriksson,1,2 Jan Nilsson,1,2 Christian Sturesson1,2 1Department of Surgery, Clinical Sciences Lund, Lund University, 2Skåne University Hospital, Lund, Sweden Abstract: Microcirculation plays a crucial role in physiological processes of tissue oxygenation and nutritional exchange. Measurement of microcirculation can be applied on many organs in various pathologies. In this paper we aim to review the technique of non-invasive methods for imaging of the microcirculation. Methods covered are: videomicroscopy techniques, laser Doppler perfusion imaging, and laser speckle contrast imaging. Videomicroscopy techniques, such as orthogonal polarization spectral imaging and sidestream dark-field imaging, provide a plentitude of information and offer direct visualization of the microcirculation but have the major drawback that they may give pressure artifacts. Both laser Doppler perfusion imaging and laser speckle contrast imaging allow non-contact measurements but have the disadvantage of their sensitivity to motion artifacts and that they are confined to relative measurement comparisons. Ideal would be a non-contact videomicroscopy method with fully automatic analysis software. Keywords: laser speckle contrast imaging, sidestream dark-field, orthogonal polarization spectral imaging, laser Dopplerimaging

  3. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods.

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T; Kornbluth, Joshua

    2016-07-01

    Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation.

  4. Non-invasive real-time imaging through scattering layers and around corners via speckle correlations

    CERN Document Server

    Katz, Ori; Fink, Mathias; Gigan, Sylvain

    2014-01-01

    Imaging with optical resolution through and inside complex samples is a difficult challenge with important applications in many fields. The fundamental problem is that inhomogeneous samples, such as biological tissues, randomly scatter and diffuse light, impeding conventional image formation. Despite many advancements, no current method enables to noninvasively image in real-time using diffused light. Here, we show that owing to the memory-effect for speckle correlations, a single image of the scattered light, captured with a standard high-resolution camera, encodes all the information that is required to image through the medium or around a corner. We experimentally demonstrate single-shot imaging through scattering media and around corners using incoherent light and various samples, from white paint to dynamic biological samples. Our lensless technique is simple, does not require laser sources, wavefront-shaping, nor time-gated detection, and is realized here using a camera-phone. It has the potential to en...

  5. Noninvasive imaging of islet grafts using positron-emission tomography

    Science.gov (United States)

    Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

    2006-07-01

    Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

  6. Noninvasive imaging of protein-protein interactions in living animals

    Science.gov (United States)

    Luker, Gary D.; Sharma, Vijay; Pica, Christina M.; Dahlheimer, Julie L.; Li, Wei; Ochesky, Joseph; Ryan, Christine E.; Piwnica-Worms, Helen; Piwnica-Worms, David

    2002-05-01

    Protein-protein interactions control transcription, cell division, and cell proliferation as well as mediate signal transduction, oncogenic transformation, and regulation of cell death. Although a variety of methods have been used to investigate protein interactions in vitro and in cultured cells, none can analyze these interactions in intact, living animals. To enable noninvasive molecular imaging of protein-protein interactions in vivo by positron-emission tomography and fluorescence imaging, we engineered a fusion reporter gene comprising a mutant herpes simplex virus 1 thymidine kinase and green fluorescent protein for readout of a tetracycline-inducible, two-hybrid system in vivo. By using micro-positron-emission tomography, interactions between p53 tumor suppressor and the large T antigen of simian virus 40 were visualized in tumor xenografts of HeLa cells stably transfected with the imaging constructs. Imaging protein-binding partners in vivo will enable functional proteomics in whole animals and provide a tool for screening compounds targeted to specific protein-protein interactions in living animals.

  7. Noninvasive dosimetry and monitoring of TTT using spectral imaging

    Science.gov (United States)

    Schuele, G.; Molnar, F. E.; Yellachich, D.; Vitkin, E.; Perelman, L. T.; Palanker, D.

    2006-02-01

    Transpupillary thermo therapy (TTT) is a slow (60 seconds) photothermal treatment of the fundus with a near-infrared (780-810nm) laser irradiating a large spot (0.5- 1. mm) on the retina. Due to high variability in ocular tissue properties and the lack of immediately observable outcome of the therapy, a real-time dosimetry is highly desirable. We found that fundus spectroscopy and spectrally-resolved imaging allow for non-invasive real-time monitoring and dosimetry of TTT. A 795nm laser was applied in rabbit eyes for 60 seconds using a 0.86mm retinal spot diameter. The fundus was illuminated with a broadband polarized light, and its reflectance spectra were measured in parallel and cross-polarizations. The fundus was also imaged in selected spectral domains. At irradiances that do not create ophthalmoscopically visible lesions the fundus reflectance increases at the wavelengths corresponding to absorption of the oxygenated blood indicating the reduced concentration of blood in the choroid. Vasoconstrictive response of the choroidal and retinal vasculature during TTT was also directly observed using spectrally-resolved imaging. At irradiances that produce ophthalmoscopically visible lesions a rapid reduction of the fundus reflectance was observed within the first 5-10 seconds of the exposure even when the visible lesions developed only by the end of the 60 second exposure. No visible lesions were produced where the laser was terminated after detection of the reduced scattering but prior to appearance of the enhanced scattering.

  8. Research progress of noninvasive high - resolution magnetic resonance imaging in carotid atherosclerotic plaque

    Directory of Open Access Journals (Sweden)

    Peng GAO

    2017-07-01

    Full Text Available Carotid atherosclerotic stenosis is closely related to recurrent ischemic stroke. Currently, therapies for carotid artery stenosis are mainly intensive medication or surgery, including carotid artery stenting (CAS and carotid endarterectomy (CEA. The prevention of stroke lies in identifying risk factors for carotid artery stenosis, screening patients with high risk of recurrent stroke, so as to benefit from medication or surgery. However, therapeutic schedule is formulated only according to the degrees of carotid artery stenosis, and there lacks of individualized treatment. Recently, new imaging modalities, such as noninvasive high.resolution MRI (HRMRI could detect the vulnerability of carotid atherosclerotic plaque. Compared with the degree of carotid artery stenosis measured by conventional DSA, noninvasive HRMRI can precisely predict the risk of ipsilateral stroke according to plaque morphology, so as to guide individualized treatment. DOI: 10.3969/j.issn.1672-6731.2017.05.012

  9. Physical And Medical Attributes Of Six Contemporary Noninvasive Imaging Techniques

    Science.gov (United States)

    Budinger, Thomas F.

    1981-11-01

    Digital subtraction angiography(DSA)is compared to five other noninvasive imaging methods with respect to physical attributes and medical applications. 1) Digital subtraction angiography measures flow channel (vessel) anatomy and vascular leaks in regions where signals from under and overlying vascular pools do not conflict in strength with the vessel or tissue of interest. 2) X-ray computed tomography, in principle, can separate the under and overlying signals, yet presently it is limited in speed, axial coverage, and computational burden for tasks DSA can efficiently perform. Possible exceptions are the dynamic spatial reconstructor (DSR) of Mayo Clinic and the system under construction at the University of California, San Francisco. 3) Heavy ion imaging measures electron density and is less sensitive to injected contrast than x-ray imaging which has the advantage of the photoelectric effect. A unique attribute of heavy ion imaging is its potential for treatment planning and the fact that beam hardening is not a physical problem. 4) Ultrasound detects surfaces, bulk tissue characteristics, and blood velocity. Doppler ultrasound competes with DSA in some regions of the body and generally involves less equipment and patient procedures. Ultrasound vessel imaging and range-gated Doppler have limitations due to sound absorption by atheromatous tissue and available imaging windows. 5) Emission tomography measures receptor site distribution, metabolism, permeability, and tissue perfusion. Resolution is limited to 7mm full width half maximum (FWHM) in the near future, and extraction of metabolic and perfusion information usually requires kinetic analyses with statistically poor data. The ability of positron tomography to measure metabolism (sugar, fatty acid, and oxygen utilization) and the ability to measure tissue perfusion with single photon tomography (17 mm FWHM) or PET (7 mm FWHM) using non-cyclotron produced radionuclides are the major unique features of emission

  10. Retinal functional imager (RFI): non-invasive functional imaging of the retina.

    Science.gov (United States)

    Ganekal, S

    2013-01-01

    Retinal functional imager (RFI) is a unique non-invasive functional imaging system with novel capabilities for visualizing the retina. The objective of this review was to show the utility of non-invasive functional imaging in various disorders. Electronic literature search was carried out using the websites www.pubmed.gov and www.google.com. The search words were retinal functional imager and non-invasive retinal imaging used in combination. The articles published or translated into English were studied. The RFI directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, metabolic responses to photic activation and generates capillary perfusion maps (CPM) that provides retinal vasculature detail similar to flourescein angiography. All of these parameters stand in a direct relationship to the function and therefore the health of the retina, and are known to be degraded in the course of retinal diseases. Detecting changes in retinal function aid early diagnosis and treatment as functional changes often precede structural changes in many retinal disorders.

  11. Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates

    DEFF Research Database (Denmark)

    De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen

    2016-01-01

    Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new...... methods to noninvasively assess brain hemodynamics. More recently these methods have made their transition to the neonatal population. The aim of this review is twofold. Firstly, to describe these newly available noninvasive methods to investigate brain hemodynamics in neonates. Secondly, to discuss...

  12. Current Trends in Sinonasal Imaging.

    Science.gov (United States)

    Huang, Benjamin Y; Senior, Brent A; Castillo, Mauricio

    2015-11-01

    As endoscopic sinus surgery (ESS) has evolved since its introduction to the United States, so has technology for imaging the sinonasal cavities. Although imaging is most frequently performed for evaluating chronic sinusitis refractory to medical therapy, its uses have expanded beyond inflammatory sinus disease. Multidetector Computed Tomography is the current workhorse for both diagnosis and preoperative planning in prospective ESS patients, while MR imaging remains a complementary tool for evaluating suspected tumors or intracranial and orbital complications of rhinosinusitis. In this article, the authors review current trends and potential future directions in the use of these modalities for sinus imaging.

  13. Anaphylaxis Imaging: Non-Invasive Measurement of Surface Body Temperature and Physical Activity in Small Animals.

    Directory of Open Access Journals (Sweden)

    Krisztina Manzano-Szalai

    Full Text Available In highly sensitized patients, the encounter with a specific allergen from food, insect stings or medications may rapidly induce systemic anaphylaxis with potentially lethal symptoms. Countless animal models of anaphylaxis, most often in BALB/c mice, were established to understand the pathophysiology and to prove the safety of different treatments. The most common symptoms during anaphylactic shock are drop of body temperature and reduced physical activity. To refine, improve and objectify the currently applied manual monitoring methods, we developed an imaging method for the automated, non-invasive measurement of the whole-body surface temperature and, at the same time, of the horizontal and vertical movement activity of small animals. We tested the anaphylaxis imaging in three in vivo allergy mouse models for i milk allergy, ii peanut allergy and iii egg allergy. These proof-of-principle experiments suggest that the imaging technology represents a reliable non-invasive method for the objective monitoring of small animals during anaphylaxis over time. We propose that the method will be useful for monitoring diseases associated with both, changes in body temperature and in physical behaviour.

  14. Injury and repair in perinatal brain injury: Insights from non-invasive MR perfusion imaging.

    Science.gov (United States)

    Wintermark, Pia

    2015-03-01

    Injury to the developing brain remains an important complication in critically ill newborns, placing them at risk for future neurodevelopment impairments. Abnormal brain perfusion is often a key mechanism underlying neonatal brain injury. A better understanding of how alternations in brain perfusion can affect normal brain development will permit the development of therapeutic strategies that prevent and/or minimize brain injury and improve the neurodevelopmental outcome of these high-risk newborns. Recently, non-invasive MR perfusion imaging of the brain has been successfully applied to the neonatal brain, which is known to be smaller and have lower brain perfusion compared to older children and adults. This article will present an overview of the potential role of non-invasive perfusion imaging by MRI to study maturation, injury, and repair in perinatal brain injury and demonstrate why this perfusion sequence is an important addition to current neonatal imaging protocols, which already include different sequences to assess the anatomy and metabolism of the neonatal brain.

  15. Current concepts in maxillofacial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boeddinghaus, Rudolf [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: rboeddinghaus@perthradclinic.com.au; Whyte, Andy [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: awhyte@perthradclinic.com.au

    2008-06-15

    A review of state-of-the-art maxillofacial imaging is presented. Current imaging techniques include intra-oral radiographs, dental panoramic tomography, multidetector helical computed tomography, cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The commonest conditions encountered in clinical radiological practice are reviewed, including maxillofacial deformities, complicated dental impactions, maxillofacial trauma, jaw lesions (cysts, neoplasms, fibro-osseous lesions (FOLs) and infections), and temporomandibular joint pathology. Pre-operative assessment for dental implant placement is also briefly reviewed.

  16. Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates : A review

    NARCIS (Netherlands)

    De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen; Petersen, Esben T; Benders, Manon Jnl

    2016-01-01

    Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new met

  17. Non-invasive imaging of skin cancer with fluorescence lifetime imaging using two photon tomography

    Science.gov (United States)

    Patalay, Rakesh; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Breunig, Hans Georg; König, Karsten; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Christopher

    2011-07-01

    Multispectral fluorescence lifetime imaging (FLIM) using two photon microscopy as a non-invasive technique for the diagnosis of skin lesions is described. Skin contains fluorophores including elastin, keratin, collagen, FAD and NADH. This endogenous contrast allows tissue to be imaged without the addition of exogenous agents and allows the in vivo state of cells and tissues to be studied. A modified DermaInspect® multiphoton tomography system was used to excite autofluorescence at 760 nm in vivo and on freshly excised ex vivo tissue. This instrument simultaneously acquires fluorescence lifetime images in four spectral channels between 360-655 nm using time-correlated single photon counting and can also provide hyperspectral images. The multispectral fluorescence lifetime images were spatially segmented and binned to determine lifetimes for each cell by fitting to a double exponential lifetime model. A comparative analysis between the cellular lifetimes from different diagnoses demonstrates significant diagnostic potential.

  18. Non-invasive electric current stimulation for restoration of vision after unilateral occipital stroke.

    Science.gov (United States)

    Gall, Carolin; Silvennoinen, Katri; Granata, Giuseppe; de Rossi, Francesca; Vecchio, Fabrizio; Brösel, Doreen; Bola, Michał; Sailer, Michael; Waleszczyk, Wioletta J; Rossini, Paolo M; Tatlisumak, Turgut; Sabel, Bernhard A

    2015-07-01

    Occipital stroke often leads to visual field loss, for which no effective treatment exists. Little is known about the potential of non-invasive electric current stimulation to ameliorate visual functions in patients suffering from unilateral occipital stroke. One reason is the traditional thinking that visual field loss after brain lesions is permanent. Since evidence is available documenting vision restoration by means of vision training or non-invasive electric current stimulation future studies should also consider investigating recovery processes after visual cortical strokes. Here, protocols of repetitive transorbital alternating current stimulation (rtACS) and transcranial direct current stimulation (tDCS) are presented and the European consortium for restoration of vision (REVIS) is introduced. Within the consortium different stimulation approaches will be applied to patients with unilateral occipital strokes resulting in homonymous hemianopic visual field defects. The aim of the study is to evaluate effects of current stimulation of the brain on vision parameters, vision-related quality of life, and physiological parameters that allow concluding about the mechanisms of vision restoration. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable. This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits. Positive results of the trials could have far-reaching implications for clinical practice. The ability of non-invasive electrical current brain stimulation to modulate the activity of neuronal networks may have implications for stroke rehabilitation also in the visual domain.

  19. New developments in non-invasive coronary imaging

    NARCIS (Netherlands)

    Dikkers, Riksta

    2008-01-01

    Coronary artery disease, and especially ischemic heart disease, is a major concern in Western society. To reduce mortality and morbidity early detection and treatment is important. Ideally, early detection should be non-invasive, fast and cheap. Coronary angiography (CAG) is a reliable technique to

  20. New developments in non-invasive coronary imaging

    NARCIS (Netherlands)

    Dikkers, Riksta

    2008-01-01

    Coronary artery disease, and especially ischemic heart disease, is a major concern in Western society. To reduce mortality and morbidity early detection and treatment is important. Ideally, early detection should be non-invasive, fast and cheap. Coronary angiography (CAG) is a reliable technique to

  1. MO-E-BRD-01: Is Non-Invasive Image-Guided Breast Brachytherapy Good?

    Energy Technology Data Exchange (ETDEWEB)

    Hiatt, J. [Rhode Island Hospital (United States)

    2015-06-15

    Is Non-invasive Image-Guided Breast Brachytherapy Good? – Jess Hiatt, MS Non-invasive Image-Guided Breast Brachytherapy (NIBB) is an emerging therapy for breast boost treatments as well as Accelerated Partial Breast Irradiation (APBI) using HDR surface breast brachytherapy. NIBB allows for smaller treatment volumes while maintaining optimal target coverage. Considering the real-time image-guidance and immobilization provided by the NIBB modality, minimal margins around the target tissue are necessary. Accelerated Partial Breast Irradiation in brachytherapy: is shorter better? - Dorin Todor, PhD VCU A review of balloon and strut devices will be provided together with the origins of APBI: the interstitial multi-catheter implant. A dosimetric and radiobiological perspective will help point out the evolution in breast brachytherapy, both in terms of devices and the protocols/clinical trials under which these devices are used. Improvements in imaging, delivery modalities and convenience are among the factors driving the ultrashort fractionation schedules but our understanding of both local control and toxicities associated with various treatments is lagging. A comparison between various schedules, from a radiobiological perspective, will be given together with a critical analysis of the issues. to review and understand the evolution and development of APBI using brachytherapy methods to understand the basis and limitations of radio-biological ‘equivalence’ between fractionation schedules to review commonly used and proposed fractionation schedules Intra-operative breast brachytherapy: Is one stop shopping best?- Bruce Libby, PhD. University of Virginia A review of intraoperative breast brachytherapy will be presented, including the Targit-A and other trials that have used electronic brachytherapy. More modern approaches, in which the lumpectomy procedure is integrated into an APBI workflow, will also be discussed. Learning Objectives: To review past and current

  2. Polyelectrolyte carbon quantum-dots: new player as a noninvasive imaging probe in Drosophila.

    Science.gov (United States)

    Parvin, Nragish; Mandal, Tapas K; Roy, Partha

    2013-10-01

    It is since long that X-ray or magnetic resonance imaging is being used for biomedical diagnosis. But till date noninvasive soft tissue imaging is not very well established. Towards this end the dietary uptake of polyelectrolyte carbon quantum dots (PECQDs) and their uses as a fluorescent probe is a new approach for imaging live specimens. In the present study we demonstrate that polyelectrolyte carbon quantum dots, which are nontoxic and have fluorescence properties can be used for in vivo imaging of internal organs. Carbon quantum dots surface were abound in polymer of free carboxyl groups making it water soluble. Our used PECQDs are less than equal to 50 nm sized and are capable to emit multi colour fluorescence. It is synthesized from waste plant materials like shaded leaves, unused shrubs, herbs etc. An exposure of 1 ppm level of soluble carbon quantum dots for 12 hours in drosophila permitted the fluorescence microscopy imaging of the different stages of their development and their non invasive internal organs without any remarkable toxic effects. Finally the fluorescent material was found to be excreted out of the animals. The current data suggests that visualization of internal organs with a fluorescent probe in live cells could help in determining the efficacy of therapeutic treatments directly without the need of any invasive procedures.

  3. Non-invasive diagnosis of liver fibrosis by FibroScan imaging

    Directory of Open Access Journals (Sweden)

    WANG Chunyan

    2013-03-01

    Full Text Available Liver fibrosis is a common etiology of chronic liver diseases. Treatment in the early stage, by anti-inflammatories or other drugs targeting the specific fibrosis-promoting factor/pathogen, can reverse the liver fibrosis; treatments in the later stages can effectively reduce the extent of fibrosis. Therefore, sensitive and accurate methods to predict and/or diagnose liver fibrosis are crucial for identifying the condition at the earliest possible stage to initiate timely therapy and inhibit disease progression. Liver biopsy is currently the gold standard for diagnosing and staging fibrosis. However, the procedure is invasive and presents surgery-related risks, such as infection and bleeding. The FibroScan imaging system represents a new, non-invasive approach to diagnose and stage liver fibrosis. This review discusses the FibroScan technology and its clinical application and efficacy.

  4. Noninvasive bioluminescence imaging of dengue virus infection in the brain of A129 mice.

    Science.gov (United States)

    Li, Xiao-Feng; Deng, Yong-Qiang; Zhao, Hui; Ye, Qing; Wang, Hong-Jiang; Li, Shi-Hua; Zhu, Shun-Ya; Shi, Pei-Yong; Qin, E-De; Zhang, Bo; Qin, Cheng-Feng

    2013-05-01

    Dengue virus (DENV) infection is one of the most important public health threats globally; however, no vaccines or effective antivirals are currently available. The bioluminescence imaging technique has emerged as a powerful tool for studies on viral pathogenesis in vitro and in vivo. In this study, using a recombinant DENV that stably expressed Renilla luciferase (Rluc-DENV), we used bioluminescence for imaging of DENV infection in the brain of A129 mice that lacked type I interferon receptors. Upon intracranial inoculation with Rluc-DENV, A129 mice developed typical neurological symptoms and rapidly succumbed to viral infection. Real-time bioluminescence intensity analysis revealed the replication kinetics of Rluc-DENV in the brain of A129 mice. Linear regression analyses showed a good correlation between photon flux and viral titers (R(2) = 0.9923). Finally, the bioluminescence model was validated using a known mouse monoclonal antibody, 2A10G6, and the therapeutic effects of this neutralizing antibody were readily monitored by live imaging in the same animal. The noninvasive bioluminescence imaging of DENV infection as described here shows distinct advantages over traditional animal models and provides a powerful tool for potential antiviral or vaccine assays against DENV infection in vivo.

  5. Diagnostic and prognostic utility of non-invasive imaging indiabetes management

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Medical imaging technologies are acquiring an increasingrelevance to assist clinicians in diagnosis and to guidemanagement and therapeutic treatment of patients,thanks to their non invasive and high resolution properties.Computed tomography, magnetic resonanceimaging, and ultrasonography are the most usedimaging modalities to provide detailed morphologicalreconstructions of tissues and organs. In addition, theuse of contrast dyes or radionuclide-labeled tracerspermits to get functional and quantitative informationabout tissue physiology and metabolism in normal anddisease state. In recent years, the development ofmultimodal and hydrid imaging techniques is comingto be the new frontier of medical imaging for thepossibility to overcome limitations of single modalitiesand to obtain physiological and pathophysiologicalmeasurements within an accurate anatomical framework.Moreover, the employment of molecular probes,such as ligands or antibodies, allows a selective in vivotargeting of biomolecules involved in specific cellularprocesses, so expanding the potentialities of imagingtechniques for clinical and research applications. Thisreview is aimed to give a survey of characteristicsof main diagnostic non-invasive imaging techniques.Current clinical appliances and future perspectives ofimaging in the diagnostic and prognostic assessment ofdiabetic complications affecting different organ systemswill be particularly addressed.

  6. Non-invasive imaging of kupffer cell status using radiolabelled mannosylated albumin

    NARCIS (Netherlands)

    Mahajan, V.; Hartimath, S.; Comley, R.; Stefan-Gueldner, M.; Roth, A.; Poelstra, K.; Reker-Smit, C.; Kamps, J.; Dierckx, R.; de Vries, Erik

    2014-01-01

    Background and Aims: Kupffer cells are responsible for maintaining liver homeostasis and have a vital role in chronic hepatotoxicity and various liver diseases. Positron Imaging Tomography (PET) is a non-invasive imaging technique that allows quantification and visualization of biochemical processes

  7. Non-invasive monitoring of living cell culture by lensless digital holography imaging

    Institute of Scientific and Technical Information of China (English)

    Yunxin Wang; Dayong Wang; Jie Zhao; Yishu Yang; Xiangqian Xiao; Huakun Cui

    2011-01-01

    @@ A non-invasive detection method for the status analysis of cell culture is presented based on digital holography technology.Lensless Fourier transform digital holography (LFTDH) configuration is developed for living cell imaging without prestaining.Complex amplitude information is reconstructed by a single inverse fast Fourier transform, and the phase aberration is corrected through the two-step phase subtraction method.The image segmentation is then applied to the automatic evaluation of confluency.Finally,the cervical cancer cell TZMbl is employed for experimental validation, and the results demonstrate that LFTDH imaging with the corresponding image post-processing can provide an automatic and non-invasive approach for monitoring living cell culture.%A non-invasive detection method for the status analysis of cell culture is presented based on digital holography technology. Lensless Fourier transform digital holography (LFTDH) configuration is developed for living cell imaging without prestaining. Complex amplitude information is reconstructed by a single inverse fast Fourier transform, and the phase aberration is corrected through the two-step phase subtraction method. The image segmentation is then applied to the automatic evaluation of confluency. Finally,the cervical cancer cell TZMbl is employed for experimental validation, and the results demonstrate that LFTDH imaging with the corresponding image post-processing can provide an automatic and non-invasive approach for monitoring living cell culture.

  8. Non-invasive imaging of kupffer cell status using radiolabelled mannosylated albumin

    NARCIS (Netherlands)

    Mahajan, V.; Hartimath, S.; Comley, R.; Stefan-Gueldner, M.; Roth, A.; Poelstra, K.; Reker-Smit, C.; Kamps, J.; Dierckx, R.; de Vries, Erik

    2014-01-01

    Background and Aims: Kupffer cells are responsible for maintaining liver homeostasis and have a vital role in chronic hepatotoxicity and various liver diseases. Positron Imaging Tomography (PET) is a non-invasive imaging technique that allows quantification and visualization of biochemical processes

  9. Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

    Directory of Open Access Journals (Sweden)

    Barbosa JA

    2011-05-01

    Full Text Available José Augusto A Barbosa¹, Alexandre B Rodrigues¹, Cleonice Carvalho C Mota¹, Márcia M Barbosa², Ana C Simões e Silva¹¹Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais (UFMG, Belo Horizonte, Minas Gerais, Brazil; ²Ecocenter, Socor Hospital, Belo Horizonte, Minas Gerais, BrazilAbstract: Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.Keywords: cardiovascular risk, endothelium dysfunction, obesity, strain and strain rate, tissue Doppler

  10. Pediatric imaging: Current and emerging techniques

    Directory of Open Access Journals (Sweden)

    Shenoy-Bhangle A

    2010-01-01

    Full Text Available Imaging has always been an important component of the clinical evaluation of pediatric patients. Rapid technological advances in imaging are making noninvasive evaluation of a wide range of pediatric diseases possible. Ultrasound and magnetic resonance imaging (MRI are two imaging modalities that do not involve ionizing radiation and are preferred imaging modalities in the pediatric population. Computed tomography (CT remains the imaging modality with the highest increase in utilization in children due to its widespread availability and rapid image acquisition. Emerging imaging applications to be discussed include MR urography, voiding urosonography with use of ultrasound contrast agents, CT dose reduction techniques, MR enterography for inflammatory bowel disease, and MR cine airway imaging.

  11. Development of multifunctional nanoparticles for targeted drug delivery and noninvasive imaging of therapeutic effect.

    Science.gov (United States)

    Sajja, Hari Krishna; East, Michael P; Mao, Hui; Wang, Y Andrew; Nie, Shuming; Yang, Lily

    2009-03-01

    Nanotechnology is a multidisciplinary scientific field undergoing explosive development. Nanometer-sized particles offer novel structural, optical and electronic properties that are not attainable with individual molecules or bulk solids. Advances in nanomedicine can be made by engineering biodegradable nanoparticles such as magnetic iron oxide nanoparticles, polymers, dendrimers and liposomes that are capable of targeted delivery of both imaging agents and anticancer drugs. This leads toward the concept and possibility of personalized medicine for the potential of early detection of cancer lesions, determination of molecular signatures of the tumor by noninvasive imaging and, most importantly, molecular targeted cancer therapy. Increasing evidence suggests that the nanoparticles, whose surface contains a targeting molecule that binds to receptors highly expressed in tumor cells, can serve as cancer image contrast agents to increase sensitivity and specificity in tumor detection. In comparison with other small molecule contrast agents, the advantage of using nanoparticles is their large surface area and the possibility of surface modifications for further conjugation or encapsulation of large amounts of therapeutic agents. Targeted nanoparticles ferry large doses of therapeutic agents into malignant cells while sparing the normal healthy cells. Such multifunctional nanodevices hold the promise of significant improvement of current clinical management of cancer patients. This review explores the development of nanoparticles for enabling and improving the targeted delivery of therapeutic agents, the potential of nanomedicine, and the development of novel and more effective diagnostic and screening techniques to extend the limits of molecular diagnostics providing point-of-care diagnosis and more personalized medicine.

  12. Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy

    Science.gov (United States)

    Hynynen, Kullervo; Jones, Ryan M.

    2016-09-01

    Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy.

  13. Obesity and the challenges of noninvasive imaging for the detection of coronary artery disease.

    Science.gov (United States)

    Lim, Siok P; Arasaratnam, Punitha; Chow, Benjamin J; Beanlands, Rob S; Hessian, Renée C

    2015-02-01

    Obesity is a significant health problem that could potentially lead to increased cardiovascular risk. Noninvasive imaging plays an important role in the evaluation of cardiovascular symptoms and risk of these patients. Selection of the appropriate test in the diagnosis of obstructive coronary artery disease in this unique population is important. In this article, we focus on the strengths, limitations, and recommendations of the various noninvasive cardiac imaging modalities available in the detection of obstructive coronary artery disease. We have suggested an algorithm to help direct investigation. Ultimately, patient management should be individualized based on clinical judgement, test availability, and local expertise.

  14. Non-invasive estimation of the metabolic heat production of breast tumors using digital infrared imaging

    CERN Document Server

    González, Francisco Javier

    2011-01-01

    In this work the metabolic heat generated by breast tumors was estimated indirectly and noninvasively from digital infrared images and numerically simulating a simplified breast model and a cancerous tumor, this parameter can be of clinical importance since it has been related to the doubling volume's time and malignancy for that particular tumor. The results indicate that digital infrared imaging has the potential to estimate in a non-invasive way the malignancy of a tumor by calculating its metabolic heat generation from bioheat thermal transfer models.

  15. Accurate non-invasive image-based cytotoxicity assays for cultured cells

    Directory of Open Access Journals (Sweden)

    Brouwer Jaap

    2010-06-01

    Full Text Available Abstract Background The CloneSelect™ Imager system is an image-based visualisation system for cell growth assessment. Traditionally cell proliferation is measured with the colorimetric MTT assay. Results Here we show that both the CloneSelect Imager and the MTT approach result in comparable EC50 values when assaying the cytotoxicity of cisplatin and oxaliplatin on various cell lines. However, the image-based technique was found non-invasive, considerably quicker and more accurate than the MTT assay. Conclusions This new image-based technique has the potential to replace the cumbersome MTT assay when fast, unbiased and high-throughput cytotoxicity assays are requested.

  16. Non-invasive method of field imaging in parallel plate waveguides

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Andryieuski, Andrei; Lavrinenko, Andrei

    2011-01-01

    We present a new non-invasive air-photonic-based method of terahertz (THz) field imaging inside a parallel plate waveguide. The method is based on THz field-enhanced second harmonic generation of the fundamental laser beam in an external electric field. We also demonstrate the direct measurements...

  17. Microgradients in bacterial colonies : use of fluorescence ratio imaging : a non-invasive technique

    NARCIS (Netherlands)

    Malakar, P.K.; Brocklehurst, T.F.; Mackie, A.R.; Wilson, P.D.G.; Zwietering, M.H.; Riet, K. van 't

    2000-01-01

    Fluorescence ratio imaging is a non-invasive technique for studying the formation of microgradients in immobilised bacterial colonies. These gradients can be quantified easily when combined with the gel cassette system designed at the Institute of Food Research, Norwich, UK. Colonies of

  18. Non-invasive imaging of Kupffer cell status using radiolabelled mannosylated albumin

    NARCIS (Netherlands)

    Mahajan, Vineet; Hartimath, Siddanna; Comley, R.; Poelstra, Klaas; Reker-Smit, Catharina; Kamps, Jan; Sijbesma, Jurgen; Stephan-Gueldner, M.; Dierckx, Rudi; de Vries, Erik

    2014-01-01

    Objectives Kupffer cells (KCs) play a key role in maintaining liver homeostasis, hepatotoxicity and in liver pathology, but their functional status cannot be directly assessed in vivo (1-5). We report a PET tracer for noninvasive translational imaging of KCs. Methods A mannosylated human serum album

  19. A Noninvasive Imaging Approach to Understanding Speech Changes following Deep Brain Stimulation in Parkinson's Disease

    Science.gov (United States)

    Narayana, Shalini; Jacks, Adam; Robin, Donald A.; Poizner, Howard; Zhang, Wei; Franklin, Crystal; Liotti, Mario; Vogel, Deanie; Fox, Peter T.

    2009-01-01

    Purpose: To explore the use of noninvasive functional imaging and "virtual" lesion techniques to study the neural mechanisms underlying motor speech disorders in Parkinson's disease. Here, we report the use of positron emission tomography (PET) and transcranial magnetic stimulation (TMS) to explain exacerbated speech impairment following…

  20. Non-invasive in-vivo imaging of stem cells after transplantation in cardiovascular tissue

    DEFF Research Database (Denmark)

    Mathiasen, Anders Bruun; Kastrup, Jens

    2013-01-01

    no improvements. To better understand the underlying mechanisms of these results, a reverse translation from bedside to bench has been opened. Non-invasive cell tracking after implantation has a pivotal role in this translation. Imaging based methods can help elucidate important issues such as retention...

  1. Clinical applications of non-invasive imaging techniques in suspected coronary artery disease and in acute myocardial infarction

    NARCIS (Netherlands)

    Nucifora, Gaetano

    2015-01-01

    Non-invasive cardiac imaging modalities play a crucial role in the diagnostic process and clinical management of patients without known coronary artery disease and patients with acute myocardial infarction. The first part of the thesis discusses the use of non-invasive imaging modalities (including

  2. Non-invasive imaging using reporter genes altering cellular water permeability

    Science.gov (United States)

    Mukherjee, Arnab; Wu, Di; Davis, Hunter C.; Shapiro, Mikhail G.

    2016-12-01

    Non-invasive imaging of gene expression in live, optically opaque animals is important for multiple applications, including monitoring of genetic circuits and tracking of cell-based therapeutics. Magnetic resonance imaging (MRI) could enable such monitoring with high spatiotemporal resolution. However, existing MRI reporter genes based on metalloproteins or chemical exchange probes are limited by their reliance on metals or relatively low sensitivity. Here we introduce a new class of MRI reporters based on the human water channel aquaporin 1. We show that aquaporin overexpression produces contrast in diffusion-weighted MRI by increasing tissue water diffusivity without affecting viability. Low aquaporin levels or mixed populations comprising as few as 10% aquaporin-expressing cells are sufficient to produce MRI contrast. We characterize this new contrast mechanism through experiments and simulations, and demonstrate its utility in vivo by imaging gene expression in tumours. Our results establish an alternative class of sensitive, metal-free reporter genes for non-invasive imaging.

  3. Imaging and finite element analysis: a methodology for non-invasive characterization of aortic tissue.

    Science.gov (United States)

    Flamini, Vittoria; Creane, Arthur P; Kerskens, Christian M; Lally, Caitríona

    2015-01-01

    Characterization of the mechanical properties of arterial tissues usually involves an invasive procedure requiring tissue removal. In this work we propose a non-invasive method to perform a biomechanical analysis of cardiovascular aortic tissue. This method is based on combining medical imaging and finite element analysis (FEA). Magnetic resonance imaging (MRI) was chosen since it presents relatively low risks for human health. A finite element model was created from the MRI images and loaded with systolic physiological pressures. By means of an optimization routine, the structural material properties were changed until average strains matched those measured by MRI. The method outlined in this work produced an estimate of the in situ properties of cardiovascular tissue based on non-invasive image datasets and finite element analysis.

  4. Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

    OpenAIRE

    Thomas Berger; Bernhard Pfeifer; Friedrich F Hanser; Florian Hintringer; Gerald Fischer; Michael Netzer; Thomas Trieb; Markus Stuehlinger; Wolfgang Dichtl; Christian Baumgartner; Otmar Pachinger; Michael Seger

    2011-01-01

    BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a f...

  5. The Accuracy of Noninvasive Imaging Techniques in Diagnosis of Carotid Plaque Morphology

    Directory of Open Access Journals (Sweden)

    Detelina Valchkova Lukanova

    2015-03-01

    CONCLUSION: The ultrasound has high accuracy for diagnostics of carotid plaque morphology, magnetic resonance imaging has high potential for tissue differentiation and multidetector computed tomography determines precisely degree of stenosis and presence of ulceration and calcifications. The three noninvasive imaging modalities are complementary for optimal evaluation of the morphology of carotid plaque. This will help to determine the risk of stroke and to decide on the best treatment – carotid endarterectomy or carotid stenting.

  6. Non-Invasive Nanoparticle Imaging Technologies for Cosmetic and Skin Care Products

    Directory of Open Access Journals (Sweden)

    Lynlee L. Lin

    2015-07-01

    Full Text Available The nanotechnology field is growing at an unprecedented rate. This is resulting in significant benefits in skin care products and formulations. Likewise, imaging technology is also advancing. The convergence of these fields offers a unique opportunity to observe and quantify the interactions of nanoparticles within cosmetic and skin care formulations. More importantly, imaging technology holds tremendous promise for understanding how formulated nanoparticles interact with our skin. Imaging technologies can be broken into two major groups that include those that require invasive sample collection and processing (e.g., electron microscopy, mass spectrometry, and super-resolution structured illumination microscopy and those that can be used in non-invasive data collection settings. Fluorescence microscopy, confocal microscopy, coherent anti-Stokes Raman scattering spectroscopy and optical coherence tomography fall into the latter category and are the focus of this review in the context of skin care product and cosmetics testing. Cosmetic and skin care product testing is most informative when carried out in volunteers. This makes invasive or disruptive analysis techniques unfeasible and supports the use of non-invasive imaging technologies. The combination of non-invasive imaging and minimally invasive microbiopsy sampling for combined imaging and molecular data is the future of skin care product testing.

  7. Current concepts in glioblastoma imaging

    Institute of Scientific and Technical Information of China (English)

    George Alexiou; Spyridon Tsiouris; Haralabos Bougias; Spyridon Voulgaris; Andreas Fotopoulos

    2012-01-01

    Glioblastoma (GBM, WHO grade Ⅳ) is the most common and the most malignant primary brain tumor occurring during adulthood, with an annual incidence of 5 cases per 100 000. Treatment involves surgical resection, followed by radiotherapy and concomitant and adjuvant temozolomide. Despite multimodality treatment, the median survival time is 15 months. Herewith we discuss the value of neuroimaging in differentiating GBM from other types of brain tumors, in guiding tumor biopsy, in making non-invasive assessment of tumor's aggressiveness, in estimating overall prognosis, in differentiating treatment -induced brain necrosis from tumor recurrence and in assessing response to treatment.

  8. Application of quantum dot nanoparticles for potential non-invasive bio-imaging of mammalian spermatozoa

    Science.gov (United States)

    Various obstacles are encountered by mammalian spermatozoa during their journey through the female genital tract, and only few or none will reach the site of fertilization. Currently, there are limited technical approaches for non-invasive investigation of spermatozoa migration after insemination. A...

  9. Noninvasive nonlinear imaging through strongly-scattering turbid layers

    CERN Document Server

    Katz, Ori; Guan, Yefeng; Silberberg, Yaron

    2014-01-01

    Diffraction-limited imaging through complex scattering media is a long sought after goal with important applications in biomedical research. In recent years, high resolution wavefront-shaping has emerged as a powerful approach to generate a sharp focus through highly scattering, visually opaque samples. However, it requires a localized feedback signal from the target point of interest, which necessitates an invasive procedure in all-optical techniques. Here, we show that by exploiting optical nonlinearities, a diffraction-limited focus can be formed inside or through a complex sample, even when the feedback signal is not localized. We prove our approach theoretically and numerically, and experimentally demonstrate it with a two-photon fluorescence signal through highly scattering biological samples. We use the formed focus to perform two-photon microscopy through highly scattering, visually opaque layers.

  10. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives

    DEFF Research Database (Denmark)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa

    2016-01-01

    Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures...... are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS...... experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation...

  11. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives

    DEFF Research Database (Denmark)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa

    2016-01-01

    Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures...... are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS...... experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation...

  12. Non-invasive imaging of epileptic seizures in vivo using photoacoustic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qizhi; Carney, Paul R; Yuan Zhen; Jiang Huabei [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States); Liu Zhao [Department of Pediatrics, Division of Pediatric Neurology, University of Florida, Gainesville, FL 32610 (United States); Chen Huanxin; Roper, Steven N [Department of Neurosurgery, University of Florida, Gainesville, FL 32610-0265 (United States)], E-mail: hjiang@bme.ufl.edu

    2008-04-07

    Non-invasive laser-induced photoacoustic tomography (PAT) is an emerging imaging modality that has the potential to image the dynamic function of the brain due to its unique ability of imaging biological tissues with high optical contrast and ultrasound resolution. Here we report the first application of our finite-element-based PAT for imaging of epileptic seizures in an animal model. In vivo photoacoustic images were obtained in rats with focal seizures induced by microinjection of bicuculline, a GABA{sub A} antagonist, into the neocortex. The seizure focus was accurately localized by PAT as confirmed with gold-standard electroencephalogram (EEG). Compared to the existing neuroimaging modalities, PAT not only has the unprecedented advantage of high spatial and temporal resolution in a single imaging modality, but also is portable and low in cost, making it possible to bring brain imaging to the bedside.

  13. Longitudinal noninvasive magnetic resonance imaging of brain microhemorrhages in BACE inhibitor-treated APP transgenic mice.

    Science.gov (United States)

    Beckmann, Nicolau; Doelemeyer, Arno; Zurbruegg, Stefan; Bigot, Karine; Theil, Diethilde; Frieauff, Wilfried; Kolly, Carine; Moulin, Pierre; Neddermann, Daniel; Kreutzer, Robert; Perrot, Ludovic; Brzak, Irena; Jacobson, Laura H; Staufenbiel, Matthias; Neumann, Ulf; Shimshek, Derya R

    2016-09-01

    Currently, several immunotherapies and BACE (Beta Site APP Cleaving Enzyme) inhibitor approaches are being tested in the clinic for the treatment of Alzheimer's disease. A crucial mechanism-related safety concern is the exacerbation of microhemorrhages, which are already present in the majority of Alzheimer patients. To investigate potential safety liabilities of long-term BACE inhibitor therapy, we used aged amyloid precursor protein (APP) transgenic mice (APP23), which robustly develop cerebral amyloid angiopathy. T2*-weighted magnetic resonance imaging (MRI), a translational method applicable in preclinical and clinical studies, was used for the detection of microhemorrhages throughout the entire brain, with subsequent histological validation. Three-dimensional reconstruction based on in vivo MRI and serial Perls' stained sections demonstrated a one-to-one matching of the lesions thus allowing for their histopathological characterization. MRI detected small Perls' positive areas with a high spatial resolution. Our data demonstrate that volumetric assessment by noninvasive MRI is well suited to monitor cerebral microhemorrhages in vivo. Furthermore, 3 months treatment of aged APP23 with the potent BACE-inhibitor NB-360 did not exacerbate microhemorrhages in contrast to Aβ-antibody β1. These results substantiate the safe use of BACE inhibitors regarding microhemorrhages in long-term clinical studies for the treatment of Alzheimer's disease.

  14. High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

    2011-03-01

    Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

  15. Hyperspectral imaging coupled with chemometric analysis for non-invasive differentiation of black pens

    Science.gov (United States)

    Chlebda, Damian K.; Majda, Alicja; Łojewski, Tomasz; Łojewska, Joanna

    2016-11-01

    Differentiation of the written text can be performed with a non-invasive and non-contact tool that connects conventional imaging methods with spectroscopy. Hyperspectral imaging (HSI) is a relatively new and rapid analytical technique that can be applied in forensic science disciplines. It allows an image of the sample to be acquired, with full spectral information within every pixel. For this paper, HSI and three statistical methods (hierarchical cluster analysis, principal component analysis, and spectral angle mapper) were used to distinguish between traces of modern black gel pen inks. Non-invasiveness and high efficiency are among the unquestionable advantages of ink differentiation using HSI. It is also less time-consuming than traditional methods such as chromatography. In this study, a set of 45 modern gel pen ink marks deposited on a paper sheet were registered. The spectral characteristics embodied in every pixel were extracted from an image and analysed using statistical methods, externally and directly on the hypercube. As a result, different black gel inks deposited on paper can be distinguished and classified into several groups, in a non-invasive manner.

  16. Non-invasive red light optogenetic pacing and optical coherence microscopy (OCM) imaging for drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Men, Jing; Li, Airong; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2017-02-01

    Cardiac pacing could be a powerful tool for investigating mammalian cardiac electrical conduction systems as well as for treatment of certain cardiac pathologies. However, traditional electrical pacing using pacemaker requires an invasive surgical procedure. Electrical currents from the implanted electrodes can also cause damage to heart tissue, further restricting its utility. Optogenetic pacing has been developed as a promising, non-invasive alternative to electrical stimulation for controlling animal heart rhythms. It induces heart contractions by shining pulsed light on transgene-generated microbial opsins, which in turn activate the light gated ion channels in animal hearts. However, commonly used opsins in optogenetic pacing, such as channelrhodopsin-2 (ChR2), require short light wavelength stimulation (475 nm), which is strongly absorbed and scattered by tissue. Here, we performed optogenetic pacing by expression of recently engineered red-shifted microbial opsins, ReaChR and CsChrimson, in a well-established animal model, Drosophila melanogaster, using the 617 nm stimulation light pulses. The OCM technique enables non-invasive optical imaging of animal hearts with high speed and ultrahigh axial and transverse resolutions. We integrated a customized OCM system with the optical stimulation system to monitor the optogenetic pacing noninvasively. The use of red-sifted opsins enabled deeper penetration of simulating light at lower power, which is promising for applications of optogenetic pacing in mammalian cardiac pathology studies or clinical treatments in the future.

  17. Profiling neuronal ion channelopathies with non-invasive brain imaging and dynamic causal models: Case studies of single gene mutations.

    Science.gov (United States)

    Gilbert, Jessica R; Symmonds, Mkael; Hanna, Michael G; Dolan, Raymond J; Friston, Karl J; Moran, Rosalyn J

    2016-01-01

    Clinical assessments of brain function rely upon visual inspection of electroencephalographic waveform abnormalities in tandem with functional magnetic resonance imaging. However, no current technology proffers in vivo assessments of activity at synapses, receptors and ion-channels, the basis of neuronal communication. Using dynamic causal modeling we compared electrophysiological responses from two patients with distinct monogenic ion channelopathies and a large cohort of healthy controls to demonstrate the feasibility of assaying synaptic-level channel communication non-invasively. Synaptic channel abnormality was identified in both patients (100% sensitivity) with assay specificity above 89%, furnishing estimates of neurotransmitter and voltage-gated ion throughput of sodium, calcium, chloride and potassium. This performance indicates a potential novel application as an adjunct for clinical assessments in neurological and psychiatric settings. More broadly, these findings indicate that biophysical models of synaptic channels can be estimated non-invasively, having important implications for advancing human neuroimaging to the level of non-invasive ion channel assays. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  18. In Vivo Bioluminescent Imaging (BLI): Noninvasive Visualization and Interrogation of Biological Processes in Living Animals

    OpenAIRE

    Steven Ripp; Sayler, Gary S.; Tingting Xu; Close, Dan M.

    2010-01-01

    In vivo bioluminescent imaging (BLI) is increasingly being utilized as a method for modern biological research. This process, which involves the noninvasive interrogation of living animals using light emitted from luciferase-expressing bioreporter cells, has been applied to study a wide range of biomolecular functions such as gene function, drug discovery and development, cellular trafficking, protein-protein interactions, and especially tumorigenesis, cancer treatment, and disease progressio...

  19. Noninvasive in vivo multispectral optoacoustic imaging of apoptosis in triple negative breast cancer using indocyanine green conjugated phosphatidylserine monoclonal antibody

    Science.gov (United States)

    Kannadorai, Ravi Kumar; Udumala, Sunil Kumar; Sidney, Yu Wing Kwong

    2016-12-01

    Noninvasive and nonradioactive imaging modality to track and image apoptosis during chemotherapy of triple negative breast cancer is much needed for an effective treatment plan. Phosphatidylserine (PS) is a biomarker transiently exposed on the outer surface of the cells during apoptosis. Its externalization occurs within a few hours of an apoptotic stimulus by a chemotherapy drug and leads to presentation of millions of phospholipid molecules per apoptotic cell on the cell surface. This makes PS an abundant and accessible target for apoptosis imaging. In the current work, we show that PS monoclonal antibody tagged with indocyanine green (ICG) can help to track and image apoptosis using multispectral optoacoustic tomography in vivo. When compared to saline control, the doxorubicin treated group showed a significant increase in uptake of ICG-PS monoclonal antibody in triple negative breast tumor xenografted in NCr nude female mice. Day 5 posttreatment had the highest optoacoustic signal in the tumor region, indicating maximum apoptosis and the tumor subsequently shrank. Since multispectral optoacoustic imaging does not involve the use of radioactivity, the longer the circulatory time of the PS antibody can be exploited to monitor apoptosis over a period of time without multiple injections of commonly used imaging probes such as Tc-99m Annexin V or F-18 ML10. The proposed apoptosis imaging technique involving multispectral optoacoustic tomography, monoclonal antibody, and near-infrared absorbing fluorescent marker can be an effective tool for imaging apoptosis and treatment planning.

  20. Noninvasive in vivo multispectral optoacoustic imaging of apoptosis in triple negative breast cancer using indocyanine green conjugated phosphatidylserine monoclonal antibody.

    Science.gov (United States)

    Kannadorai, Ravi Kumar; Udumala, Sunil Kumar; Sidney, Yu Wing Kwong

    2016-12-01

    Noninvasive and nonradioactive imaging modality to track and image apoptosis during chemotherapy of triple negative breast cancer is much needed for an effective treatment plan. Phosphatidylserine (PS) is a biomarker transiently exposed on the outer surface of the cells during apoptosis. Its externalization occurs within a few hours of an apoptotic stimulus by a chemotherapy drug and leads to presentation of millions of phospholipid molecules per apoptotic cell on the cell surface. This makes PS an abundant and accessible target for apoptosis imaging. In the current work, we show that PS monoclonal antibody tagged with indocyanine green (ICG) can help to track and image apoptosis using multispectral optoacoustic tomography triple negative breast tumor xenografted in NCr nude female mice. Day 5 posttreatment had the highest optoacoustic signal in the tumor region, indicating maximum apoptosis and the tumor subsequently shrank. Since multispectral optoacoustic imaging does not involve the use of radioactivity, the longer the circulatory time of the PS antibody can be exploited to monitor apoptosis over a period of time without multiple injections of commonly used imaging probes such as Tc-99m Annexin V or F-18 ML10. The proposed apoptosis imaging technique involving multispectral optoacoustic tomography, monoclonal antibody, and near-infrared absorbing fluorescent marker can be an effective tool for imaging apoptosis and treatment planning.

  1. Application of quantum dot nanoparticles for potential non-invasive bio-imaging of mammalian spermatozoa

    Directory of Open Access Journals (Sweden)

    Feugang Jean M

    2012-12-01

    Full Text Available Abstract Background Various obstacles are encountered by mammalian spermatozoa during their journey through the female genital tract, and only few or none will reach the site of fertilization. Currently, there are limited technical approaches for non-invasive investigation of spermatozoa migration after insemination. As the knowledge surrounding sperm behavior throughout the female genital tract still remains elusive, the recent development of self-illuminating quantum dot nanoparticles may present a potential means for real-time in vitro and in vivo monitoring of spermatozoa. Results Here, we show the ability of boar spermatozoa to harmlessly interact and incorporate bioluminescent resonance energy transfer-conjugated quantum dot (BRET-QD nanoparticles. The confocal microscope revealed in situ fluorescence of BRET-QD in the entire spermatozoon, while the ultra-structural analysis using the transmission electron microscope indicated BRET-QD localization on the sperm plasma membrane and intracellular compartment. In controlled-in vitro assays, bioluminescent imaging demonstrated that spermatozoa incubated with BRET-QD and luciferase substrate (coelenterazine emit light (photons/sec above the background, which confirmed the in situ fluorescence imaging. Most importantly, sperm motility, viability, and fertilizing potential were not affected by the BRET-QD incorporation when used at an appropriated ratio. Conclusions Our results demonstrate that pig spermatozoa can incorporate BRET-QD nanoparticles without affecting their motility and capacity to interact with the oocyte when used at an appropriated balance. We anticipate that our study will enable in-depth exploration of the male components of in vivo migration, fertilization, and embryonic development at the molecular level using this novel approach.

  2. Noninvasive three-dimensional live imaging methodology for the spindles at meiosis and mitosis

    Science.gov (United States)

    Zheng, Jing-gao; Huo, Tiancheng; Tian, Ning; Chen, Tianyuan; Wang, Chengming; Zhang, Ning; Zhao, Fengying; Lu, Danyu; Chen, Dieyan; Ma, Wanyun; Sun, Jia-lin; Xue, Ping

    2013-05-01

    The spindle plays a crucial role in normal chromosome alignment and segregation during meiosis and mitosis. Studying spindles in living cells noninvasively is of great value in assisted reproduction technology (ART). Here, we present a novel spindle imaging methodology, full-field optical coherence tomography (FF-OCT). Without any dye labeling and fixation, we demonstrate the first successful application of FF-OCT to noninvasive three-dimensional (3-D) live imaging of the meiotic spindles within the mouse living oocytes at metaphase II as well as the mitotic spindles in the living zygotes at metaphase and telophase. By post-processing of the 3-D dataset obtained with FF-OCT, the important morphological and spatial parameters of the spindles, such as short and long axes, spatial localization, and the angle of meiotic spindle deviation from the first polar body in the oocyte were precisely measured with the spatial resolution of 0.7 μm. Our results reveal the potential of FF-OCT as an imaging tool capable of noninvasive 3-D live morphological analysis for spindles, which might be useful to ART related procedures and many other spindle related studies.

  3. Non-invasively measured cardiac magnetic field maps improve the estimation of the current distribution

    OpenAIRE

    Kosch, Olaf; Steinhoff, Uwe; Trahms, Lutz; Trontelj, Zvonko; Jazbinšek, Vojko

    2015-01-01

    Comprehensive body surface potential mapping (BSPM) and magnetic field mapping (MFM) measurements have been carried out in order to improve the estimation of the current distribution generated by the human heart. Electric and magnetic fields and also the planar gradient of the magnetic field during the QRS complex were imaged as a time series of field maps. A model of the current distribution should explain the features of both BSPM and MFM. Simulated maps generated by a single dipole or a st...

  4. Non-invasive assessment of bone quantity and quality in human trabeculae using scanning ultrasound imaging

    Science.gov (United States)

    Xia, Yi

    Fractures and associated bone fragility induced by osteoporosis and osteopenia are widespread health threat to current society. Early detection of fracture risk associated with bone quantity and quality is important for both the prevention and treatment of osteoporosis and consequent complications. Quantitative ultrasound (QUS) is an engineering technology for monitoring bone quantity and quality of humans on earth and astronauts subjected to long duration microgravity. Factors currently limiting the acceptance of QUS technology involve precision, accuracy, single index and standardization. The objective of this study was to improve the accuracy and precision of an image-based QUS technique for non-invasive evaluation of trabecular bone quantity and quality by developing new techniques and understanding ultrasound/tissue interaction. Several new techniques have been developed in this dissertation study, including the automatic identification of irregular region of interest (iROI) in bone, surface topology mapping (STM) and mean scattering spacing (MSS) estimation for evaluating trabecular bone structure. In vitro results have shown that (1) the inter- and intra-observer errors in QUS measurement were reduced two to five fold by iROI compared to previous results; (2) the accuracy of QUS parameter, e.g., ultrasound velocity (UV) through bone, was improved 16% by STM; and (3) the averaged trabecular spacing can be estimated by MSS technique (r2=0.72, p<0.01). The measurement errors of BUA and UV introduced by the soft tissue and cortical shells in vivo can be quantified by developed foot model and simplified cortical-trabecular-cortical sandwich model, which were verified by the experimental results. The mechanisms of the errors induced by the cortical and soft tissues were revealed by the model. With developed new techniques and understanding of sound-tissue interaction, in vivo clinical trail and bed rest study were preformed to evaluate the performance of QUS in

  5. Scanning superlens microscopy for non-invasive large field-of-view visible light nanoscale imaging

    Science.gov (United States)

    Wang, Feifei; Liu, Lianqing; Yu, Haibo; Wen, Yangdong; Yu, Peng; Liu, Zhu; Wang, Yuechao; Li, Wen Jung

    2016-12-01

    Nanoscale correlation of structural information acquisition with specific-molecule identification provides new insight for studying rare subcellular events. To achieve this correlation, scanning electron microscopy has been combined with super-resolution fluorescent microscopy, despite its destructivity when acquiring biological structure information. Here we propose time-efficient non-invasive microsphere-based scanning superlens microscopy that enables the large-area observation of live-cell morphology or sub-membrane structures with sub-diffraction-limited resolution and is demonstrated by observing biological and non-biological objects. This microscopy operates in both non-invasive and contact modes with ~200 times the acquisition efficiency of atomic force microscopy, which is achieved by replacing the point of an atomic force microscope tip with an imaging area of microspheres and stitching the areas recorded during scanning, enabling sub-diffraction-limited resolution. Our method marks a possible path to non-invasive cell imaging and simultaneous tracking of specific molecules with nanoscale resolution, facilitating the study of subcellular events over a total cell period.

  6. Noninvasive metabolic imaging of engineered 3D human adipose tissue in a perfusion bioreactor.

    Directory of Open Access Journals (Sweden)

    Andrew Ward

    Full Text Available The efficacy and economy of most in vitro human models used in research is limited by the lack of a physiologically-relevant three-dimensional perfused environment and the inability to noninvasively quantify the structural and biochemical characteristics of the tissue. The goal of this project was to develop a perfusion bioreactor system compatible with two-photon imaging to noninvasively assess tissue engineered human adipose tissue structure and function in vitro. Three-dimensional (3D vascularized human adipose tissues were engineered in vitro, before being introduced to a perfusion environment and tracked over time by automated quantification of endogenous markers of metabolism using two-photon excited fluorescence (TPEF. Depth-resolved image stacks were analyzed for redox ratio metabolic profiling and compared to prior analyses performed on 3D engineered adipose tissue in static culture. Traditional assessments with H&E staining were used to qualitatively measure extracellular matrix generation and cell density with respect to location within the tissue. The distribution of cells within the tissue and average cellular redox ratios were different between static and perfusion cultures, while the trends of decreased redox ratio and increased cellular proliferation with time in both static and perfusion cultures were similar. These results establish a basis for noninvasive optical tracking of tissue structure and function in vitro, which can be applied to future studies to assess tissue development or drug toxicity screening and disease progression.

  7. Noninvasive metabolic imaging of engineered 3D human adipose tissue in a perfusion bioreactor.

    Science.gov (United States)

    Ward, Andrew; Quinn, Kyle P; Bellas, Evangelia; Georgakoudi, Irene; Kaplan, David L

    2013-01-01

    The efficacy and economy of most in vitro human models used in research is limited by the lack of a physiologically-relevant three-dimensional perfused environment and the inability to noninvasively quantify the structural and biochemical characteristics of the tissue. The goal of this project was to develop a perfusion bioreactor system compatible with two-photon imaging to noninvasively assess tissue engineered human adipose tissue structure and function in vitro. Three-dimensional (3D) vascularized human adipose tissues were engineered in vitro, before being introduced to a perfusion environment and tracked over time by automated quantification of endogenous markers of metabolism using two-photon excited fluorescence (TPEF). Depth-resolved image stacks were analyzed for redox ratio metabolic profiling and compared to prior analyses performed on 3D engineered adipose tissue in static culture. Traditional assessments with H&E staining were used to qualitatively measure extracellular matrix generation and cell density with respect to location within the tissue. The distribution of cells within the tissue and average cellular redox ratios were different between static and perfusion cultures, while the trends of decreased redox ratio and increased cellular proliferation with time in both static and perfusion cultures were similar. These results establish a basis for noninvasive optical tracking of tissue structure and function in vitro, which can be applied to future studies to assess tissue development or drug toxicity screening and disease progression.

  8. Non-invasive multimodal functional imaging of the intestine with frozen micellar naphthalocyanines

    Science.gov (United States)

    Zhang, Yumiao; Jeon, Mansik; Rich, Laurie J.; Hong, Hao; Geng, Jumin; Zhang, Yin; Shi, Sixiang; Barnhart, Todd E.; Alexandridis, Paschalis; Huizinga, Jan D.; Seshadri, Mukund; Cai, Weibo; Kim, Chulhong; Lovell, Jonathan F.

    2014-08-01

    There is a need for safer and improved methods for non-invasive imaging of the gastrointestinal tract. Modalities based on X-ray radiation, magnetic resonance and ultrasound suffer from limitations with respect to safety, accessibility or lack of adequate contrast. Functional intestinal imaging of dynamic gut processes has not been practical using existing approaches. Here, we report the development of a family of nanoparticles that can withstand the harsh conditions of the stomach and intestine, avoid systemic absorption, and provide good optical contrast for photoacoustic imaging. The hydrophobicity of naphthalocyanine dyes was exploited to generate purified ∼20 nm frozen micelles, which we call nanonaps, with tunable and large near-infrared absorption values (>1,000). Unlike conventional chromophores, nanonaps exhibit non-shifting spectra at ultrahigh optical densities and, following oral administration in mice, passed safely through the gastrointestinal tract. Non-invasive, non-ionizing photoacoustic techniques were used to visualize nanonap intestinal distribution with low background and remarkable resolution, and enabled real-time intestinal functional imaging with ultrasound co-registration. Positron emission tomography following seamless nanonap radiolabelling allowed complementary whole-body imaging.

  9. Noninvasive measurement of pharmacokinetics by near-infrared fluorescence imaging in the eye of mice

    Science.gov (United States)

    Dobosz, Michael; Strobel, Steffen; Stubenrauch, Kay-Gunnar; Osl, Franz; Scheuer, Werner

    2014-01-01

    Purpose: For generating preclinical pharmacokinetics (PKs) of compounds, blood is drawn at different time points and levels are quantified by different analytical methods. In order to receive statistically meaningful data, 3 to 5 animals are used for each time point to get serum peak-level and half-life of the compound. Both characteristics are determined by data interpolation, which may influence the accuracy of these values. We provide a method that allows continuous monitoring of blood levels noninvasively by measuring the fluorescence intensity of labeled compounds in the eye and other body regions of anesthetized mice. Procedures: The method evaluation was performed with four different fluorescent compounds: (i) indocyanine green, a nontargeting dye; (ii) OsteoSense750, a bone targeting agent; (iii) tumor targeting Trastuzumab-Alexa750; and (iv) its F(-alxea750 fragment. The latter was used for a direct comparison between fluorescence imaging and classical blood analysis using enzyme-linked immunosorbent assay (ELISA). Results: We found an excellent correlation between blood levels measured by noninvasive eye imaging with the results generated by classical methods. A strong correlation between eye imaging and ELISA was demonstrated for the F( fragment. Whole body imaging revealed a compound accumulation in the expected regions (e.g., liver, bone). Conclusions: The combination of eye and whole body fluorescence imaging enables the simultaneous measurement of blood PKs and biodistribution of fluorescent-labeled compounds.

  10. Noninvasive imaging analysis of biological tissue associated with laser thermal injury.

    Science.gov (United States)

    Chang, Cheng-Jen; Yu, De-Yi; Hsiao, Yen-Chang; Ho, Kuang-Hua

    2017-04-01

    The purpose of our study is to use a noninvasive tomographic imaging technique with high spatial resolution to characterize and monitor biological tissue responses associated with laser thermal injury. Optical doppler tomography (ODT) combines laser doppler flowmetry (LDF) with optical coherence tomography (OCT) to obtain high resolution tomographic velocity and structural images of static and moving constituents in highly scattering biological tissues. A SurgiLase XJ150 carbon dioxide (CO2) laser using a continuous mode of 3 watts (W) was used to create first, second or third degree burns on anesthetized Sprague-Dawley rats. Additional parameters for laser thermal injury were assessed as well. The rationale for using ODT in the evaluation of laser thermal injury offers a means of constructing a high resolution tomographic image of the structure and perfusion of laser damaged skin. In the velocity images, the blood flow is coded at 1300 μm/s and 0 velocity, 1000 μm/s and 0 velocity, 700 μm/s and 0 velocity adjacent to the first, second, and third degree injuries, respectively. ODT produces exceptional spatial resolution while having a non-invasive way of measurement, therefore, ODT is an accurate measuring method for high-resolution fluid flow velocity and structural images for biological tissue with laser thermal injury. Copyright © 2017 Chang Gung University. Published by Elsevier B.V. All rights reserved.

  11. Noninvasive Multimodal Imaging to Predict Recovery of Locomotion after Extended Limb Ischemia.

    Directory of Open Access Journals (Sweden)

    Jason S Radowsky

    Full Text Available Acute limb ischemia is a common cause of morbidity and mortality following trauma both in civilian centers and in combat related injuries. Rapid determination of tissue viability and surgical restoration of blood flow are desirable, but not always possible. We sought to characterize the response to increasing periods of hind limb ischemia in a porcine model such that we could define a period of critical ischemia (the point after which irreversible neuromuscular injury occurs, evaluate non-invasive methods for characterizing that ischemia, and establish a model by which we could predict whether or not the animal's locomotion would return to baselines levels post-operatively. Ischemia was induced by either application of a pneumatic tourniquet or vessel occlusion (performed by clamping the proximal iliac artery and vein at the level of the inguinal ligament. The limb was monitored for the duration of the procedure with both 3-charge coupled device (3CCD and infrared (IR imaging for tissue oxygenation and perfusion, respectively. The experimental arms of this model are effective at inducing histologically evident muscle injury with some evidence of expected secondary organ damage, particularly in animals with longer ischemia times. Noninvasive imaging data shows excellent correlation with post-operative functional outcomes, validating its use as a non-invasive means of viability assessment, and directly monitors post-occlusive reactive hyperemia. A classification model, based on partial-least squares discriminant analysis (PLSDA of imaging variables only, successfully classified animals as "returned to normal locomotion" or "did not return to normal locomotion" with 87.5% sensitivity and 66.7% specificity after cross-validation. PLSDA models generated from non-imaging data were not as accurate (AUC of 0.53 compared the PLSDA model generated from only imaging data (AUC of 0.76. With some modification, this limb ischemia model could also serve as a

  12. Noninvasive cortical stimulation with transcranial direct current stimulation in Parkinson's disease.

    Science.gov (United States)

    Fregni, Felipe; Boggio, Paulo S; Santos, Marcelo C; Lima, Moises; Vieira, Adriana L; Rigonatti, Sergio P; Silva, M Teresa A; Barbosa, Egberto R; Nitsche, Michael A; Pascual-Leone, Alvaro

    2006-10-01

    Electrical stimulation of deep brain structures, such as globus pallidus and subthalamic nucleus, is widely accepted as a therapeutic tool for patients with Parkinson's disease (PD). Cortical stimulation either with epidural implanted electrodes or repetitive transcranial magnetic stimulation can be associated with motor function enhancement in PD. We aimed to study the effects of another noninvasive technique of cortical brain stimulation, transcranial direct current stimulation (tDCS), on motor function and motor-evoked potential (MEP) characteristics of PD patients. We tested tDCS using different electrode montages [anodal stimulation of primary motor cortex (M1), cathodal stimulation of M1, anodal stimulation of dorsolateral prefrontal cortex (DLPFC), and sham-stimulation] and evaluated the effects on motor function--as indexed by Unified Parkinson's Disease Rating Scale (UPDRS), simple reaction time (sRT) and Purdue Pegboard test--and on corticospinal motor excitability (MEP characteristics). All experiments were performed in a double-blinded manner. Anodal stimulation of M1 was associated with a significant improvement of motor function compared to sham-stimulation in the UPDRS (P stimulation of M1 or anodal stimulation of DLPFC. Furthermore, whereas anodal stimulation of M1 significantly increased MEP amplitude and area, cathodal stimulation of M1 significantly decreased them. There was a trend toward a significant correlation between motor function improvement after M1 anodal-tDCS and MEP area increase. These results confirm and extend the notion that cortical brain stimulation might improve motor function in patients with PD.

  13. Evaluation of biolistic gene transfer methods in vivo using non-invasive bioluminescent imaging techniques

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    Daniell Henry

    2011-06-01

    Full Text Available Abstract Background Gene therapy continues to hold great potential for treating many different types of disease and dysfunction. Safe and efficient techniques for gene transfer and expression in vivo are needed to enable gene therapeutic strategies to be effective in patients. Currently, the most commonly used methods employ replication-defective viral vectors for gene transfer, while physical gene transfer methods such as biolistic-mediated ("gene-gun" delivery to target tissues have not been as extensively explored. In the present study, we evaluated the efficacy of biolistic gene transfer techniques in vivo using non-invasive bioluminescent imaging (BLI methods. Results Plasmid DNA carrying the firefly luciferase (LUC reporter gene under the control of the human Cytomegalovirus (CMV promoter/enhancer was transfected into mouse skin and liver using biolistic methods. The plasmids were coupled to gold microspheres (1 μm diameter using different DNA Loading Ratios (DLRs, and "shot" into target tissues using a helium-driven gene gun. The optimal DLR was found to be in the range of 4-10. Bioluminescence was measured using an In Vivo Imaging System (IVIS-50 at various time-points following transfer. Biolistic gene transfer to mouse skin produced peak reporter gene expression one day after transfer. Expression remained detectable through four days, but declined to undetectable levels by six days following gene transfer. Maximum depth of tissue penetration following biolistic transfer to abdominal skin was 200-300 μm. Similarly, biolistic gene transfer to mouse liver in vivo also produced peak early expression followed by a decline over time. In contrast to skin, however, liver expression of the reporter gene was relatively stable 4-8 days post-biolistic gene transfer, and remained detectable for nearly two weeks. Conclusions The use of bioluminescence imaging techniques enabled efficient evaluation of reporter gene expression in vivo. Our results

  14. Non-invasive in vivo imaging of myocardial apoptosis and necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Flotats, Albert; Carrio, Ignasi [Hospital de la Santa Creu i Sant Pau, Barcelona (Spain)

    2003-04-01

    Myocardial necrosis plays an important role in the pathogenesis of various cardiovascular disorders and can result from different myocardial insults. Its non-invasive identification and localisation therefore may help in the diagnosis of these disorders, as well as in prognosis and assessment of treatment response. Apoptosis, or programmed cell death, is important in the spectrum of myocardial damage since it is gradually becoming more apparent that cell death may begin as apoptosis and not as necrosis. First attempts to directly visualise the area of myocardial necrosis were based on recognition of myocardial infarction with ''hot spot imaging agents'' in patients with chest pain. Since then, the study of myocardial necrosis with gamma imaging agents has gone beyond the detection of myocardial infarction, and attempts have been made to diagnose other cardiovascular disorders associated with cardiac cell death such as heart transplant rejection, myocarditis, cardiotoxicity and cardiomyopathies. Traditionally, two hot spot imaging agents have been used for the detection of myocardial necrosis, {sup 99m}Tc-pyrophosphate and {sup 111}In-antimyosin. In addition, preliminary studies have demonstrated promising results with {sup 99m}Tc-glucarate. Recently, {sup 99m}Tc-annexin V has been successfully used for non-invasive gamma imaging of apoptosis after acute myocardial infarction, acute myocardial ischaemia, acute cardiac allograft rejection and malignant intracardiac tumours. This review article focusses on the characteristics of these different myocardial necrotic and apoptotic markers and compares their role in the assessment of myocardial damage. (orig.)

  15. Noninvasive bioluminescence imaging of the dynamics of sanguinarine induced apoptosis via activation of reactive oxygen species.

    Science.gov (United States)

    Wang, Yan; Zhang, Beilei; Liu, Wei; Dai, Yunpeng; Shi, Yaru; Zeng, Qi; Wang, Fu

    2016-04-19

    Most chemotherapeutic drugs exert their anti-tumor effects primarily by triggering a final pathway leading to apoptosis. Noninvasive imaging of apoptotic events in preclinical models would greatly facilitate the development of apoptosis-inducing compounds and evaluation of their therapeutic efficacy. Here we employed a cyclic firefly luciferase (cFluc) reporter to screen potential pro-apoptotic compounds from a number of natural agents. We demonstrated that sanguinarine (SANG) could induce apoptosis in a dose- and time-dependent manner in UM-SCC-22B head and neck cancer cells. Moreover, SANG-induced apoptosis was associated with the generation of reactive oxygen species (ROS) and activation of c-Jun-N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) signal pathways. After intravenous administration with SANG in 22B-cFluc xenograft models, a dramatic increase of luminescence signal can be detected as early as 48 h post-treatment, as revealed by longitudinal bioluminescence imaging in vivo. Remarkable apoptotic cells reflected from ex vivo TUNEL staining confirmed the imaging results. Importantly, SANG treatment caused distinct tumor growth retardation in mice compared with the vehicle-treated group. Taken together, our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cFluc reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation.

  16. Opportunities for guided multichannel non-invasive transcranial current stimulation in post-stroke rehabilitation

    Directory of Open Access Journals (Sweden)

    Begonya eOtal

    2016-02-01

    Full Text Available Stroke is a leading cause of serious long-term disability worldwide. Functional outcome depends on stroke location, severity and early intervention. Conventional rehabilitation strategies have limited effectiveness, and new treatments still fail to keep pace, in part due to a lack of understanding of the different stages in brain recovery and the vast heterogeneity in the post-stroke population. Innovative methodologies for restorative neurorehabilitation are required to reduce long-term disability and socioeconomic burden. Neuroplasticity is involved in post-stroke functional disturbances, and also during rehabilitation. Tackling post-stroke neuroplasticity by non-invasive brain stimulation is regarded as promising, but efficacy might be limited because of rather uniform application across patients despite individual heterogeneity of lesions, symptoms and other factors. Transcranial direct current stimulation (tDCS induces and modulates neuroplasticity, and has been shown to be able to improve motor and cognitive functions. tDCS is suited to improve post-stroke rehabilitation outcomes, but effect sizes are often moderate and suffer from variability. Indeed, the location, extent and pattern of functional network connectivity disruption should be considered when determining the optimal location sites for tDCS therapies. Here, we present potential opportunities for neuroimaging-guided tDCS-based rehabilitation strategies after stroke that could be personalized. We introduce innovative multimodal intervention protocols based on multichannel tDCS montages, neuroimaging methods and real-time closed-loop systems to guide therapy. This might help to overcome current treatment limitations in post-stroke rehabilitation and increase our general understanding of adaptive neuroplasticity leading to neural reorganization after stroke.

  17. Non-invasive monitoring of Streptococcus pyogenes vaccine efficacy using biophotonic imaging.

    Directory of Open Access Journals (Sweden)

    Faraz M Alam

    Full Text Available Streptococcus pyogenes infection of the nasopharynx represents a key step in the pathogenic cycle of this organism and a major focus for vaccine development, requiring robust models to facilitate the screening of potentially protective antigens. One antigen that may be an important target for vaccination is the chemokine protease, SpyCEP, which is cell surface-associated and plays a role in pathogenesis. Biophotonic imaging (BPI can non-invasively characterize the spatial location and abundance of bioluminescent bacteria in vivo. We have developed a bioluminescent derivative of a pharyngeal S. pyogenes strain by transformation of an emm75 clinical isolate with the luxABCDE operon. Evaluation of isogenic recombinant strains in vitro and in vivo confirmed that bioluminescence conferred a growth deficit that manifests as a fitness cost during infection. Notwithstanding this, bioluminescence expression permitted non-invasive longitudinal quantitation of S. pyogenes within the murine nasopharynx albeit with a detection limit corresponding to approximately 10(5 bacterial colony forming units (CFU in this region. Vaccination of mice with heat killed streptococci, or with SpyCEP led to a specific IgG response in the serum. BPI demonstrated that both vaccine candidates reduced S. pyogenes bioluminescence emission over the course of nasopharyngeal infection. The work suggests the potential for BPI to be used in the non-invasive longitudinal evaluation of potential S. pyogenes vaccines.

  18. Acoustic radiation force imaging sonoelastography for noninvasive staging of liver fibrosis

    Institute of Scientific and Technical Information of China (English)

    Carmen Fierbinteanu-Braticevici; Dan Andronescu; Radu Usvat; Dragos Cretoiu; Cristian Baicus; Gabriela Marinoschi

    2009-01-01

    AIM: To investigate the diagnostic accuracy of acoustic radiation force impulse (ARFI) imaging as a noninvasive method for the assessment of liver fibrosis in chronic hepatitis C (CHC) patients.METHODS: We performed a prospective blind comparison of ARFI elastography, APRI index and FibroMax in a consecutive series of patients who underwent liver biopsy for CHC in University Hospital Bucharest. Histopathological staging of liver fibrosis according to the METAVIR scoring system served as the reference. A total of 74 patients underwent ARFI elastography, APRI index, FibroMax and successful liver biopsy.RESULTS: The noninvasive tests had a good correlation with the liver biopsy results. The most powerful test in predicting fibrosis was ARFI elastography. The diagnostic accuracy of ARFI elastography, expressed as area under receiver operating characteristic curve (AUROC) had a validity of 90.2% (95% CI AUROC =0.831-0.972, P < 0.001) for the diagnosis of significant fibrosis (F ≥ 2). ARFI sonoelastography predicted even better F3 or F4 fibrosis (AUROC = 0.993, 95% CI =0.979-1).CONCLUSION: ARFI elastography had very good accuracy for the assessment of liver fibrosis and was superior to other noninvasive methods (APRI Index,FibroMax) for staging liver fibrosis.

  19. [Design and application of noninvasive tissue recognition imaging in tomography of human skin and crystal structure].

    Science.gov (United States)

    Yang, Bor-wen; Yang, Pao-keng; Chang, Yuan-shuo; Chen, Xin-chang; Shih, Wen-tse

    2010-09-01

    Cosmetic industry grows fast in recent years. To reveal the image of dermal structure, it is necessary to apply three-dimensional medical imaging technology. To reduce the invasiveness of laser source on tissues, tissue recognition imaging is proposed to retrieve the intrinsic optical property, namely, the reflection spectrum of every scanned point for imaging. The reflection spectra of main kinds of skin tissue, such as melanin, collagen and hemoglobin, were established as reference database. Broad-band rays were then employed to derive the reflection spectrum of each scanned sample element; the tissue type of the scanned point was identified by cross-correlation of the derived spectrum and the database. In imaging program, all scanned points were filled in with their corresponding tissue color, e.g., black for melanin, white for collagen, or red for hemoglobin, and finally the colored skin tomography resulted. Tissue recognition imaging has merits of easy configuration, low cost, color imaging, high resolution and real non-invasiveness. Substituting LED modules for its spectrometer, tissue recognition imaging is promising to be miniaturized as personal and portable skincare devices, which have great potential in future cosmetic market.

  20. Dynamic tissue phantoms and their use in assessment of a noninvasive optical plethysmography imaging device

    Science.gov (United States)

    Thatcher, Jeffrey E.; Plant, Kevin D.; King, Darlene R.; Block, Kenneth L.; Fan, Wensheng; DiMaio, J. Michael

    2014-05-01

    Non-contact photoplethysmography (PPG) has been studied as a method to provide low-cost and non-invasive medical imaging for a variety of near-surface pathologies and two dimensional blood oxygenation measurements. Dynamic tissue phantoms were developed to evaluate this technology in a laboratory setting. The purpose of these phantoms was to generate a tissue model with tunable parameters including: blood vessel volume change; pulse wave frequency; and optical scattering and absorption parameters. A non-contact PPG imaging system was evaluated on this model and compared against laser Doppler imaging (LDI) and a traditional pulse oximeter. Results indicate non-contact PPG accurately identifies pulse frequency and appears to identify signals from optically dense phantoms with significantly higher detection thresholds than LDI.

  1. Use of noninvasive imaging in the evaluation of coarctation of aorta.

    Science.gov (United States)

    Darabian, Sirous; Zeb, Irfan; Rezaeian, Panteha; Razipour, Aryabod; Budoff, Matthew

    2013-01-01

    Coarctation of the aorta is a congenital heart disease, which is often associated with other cardiac and noncardiac anomalies. Early diagnoses, information about associated anomalies, and defining the severity of the disease are critical for appropriate treatment planning. In this regard, several noninvasive imaging modalities, such as echocardiography, cardiac computed tomography (CT), and cardiac magnetic resonance imaging, have been used. Echocardiography, as an available and safe method, should be used as a primary screening test. It is also useful for intraoperative and hemodynamic studies, but cardiac CT is recommended before any corrective procedure or surgery. Cardiac CT angiography showed an excellent spatial resolution and a good capability for finding associated anomalies. After correction of coarctation of the aorta, serial cardiac magnetic resonance imaging is most commonly performed to avoid repeated radiation exposure.

  2. Non-invasive detection of murals with pulsed terahertz reflected imaging system

    Science.gov (United States)

    Yuan, Minjie; Sun, Wenfeng; Wang, Xinke; Ye, Jiasheng; Wang, Sen; Zhang, Qunxi; Zhang, Yan

    2015-11-01

    Pulsed terahertz reflected imaging technology has been expected to have great potential for the non-invasive analysis of artworks. In this paper, three types of defects hidden in the plaster used to simulate the cases of defects in the murals, have been investigated by a pulsed terahertz reflected imaging system. These preset defects include a circular groove, a cross-shaped slit and a piece of "Y-type" metal plate built in the plaster. With the terahertz reflective tomography, information about defects has been determined involving the thickness from the surface of sample to the built-in defect, the profile and distribution of the defect. Additionally, three-dimensional analyses have been performed in order to reveal the internal structure of defects. Terahertz reflective imaging can be applied to the defect investigation of the murals.

  3. Noninvasive Imaging of Cell-Mediated Therapy for Treatment of Cancer

    Science.gov (United States)

    Akins, Elizabeth J.; Dubey, Purnima

    2013-01-01

    Cell-mediated therapy (immunotherapy) for the treatment of cancer is an active area of investigation in animal models and clinical trials. Despite many advances, objective responses to immunotherapy are observed in a small number of cases, for certain tumor types. To better understand differences in outcomes, it is critical to develop assays for tracking effector cell localization and function in situ. The fairly recent use of molecular imaging techniques to track cell populations has presented researchers and clinicians with a powerful diagnostic tool for determining the efficacy of cell-mediated therapy for the treatment of cancer. This review highlights the application of whole-body noninvasive radioisotopic, magnetic, and optical imaging methods for monitoring effector cells in vivo. Issues that affect sensitivity of detection, such as methods of cell marking, efficiency of cell labeling, toxicity, and limits of detection of imaging modalities, are discussed. PMID:18523073

  4. Targets and probes for non-invasive imaging of β-cells

    Energy Technology Data Exchange (ETDEWEB)

    Jodal, Andreas; Behe, Martin [Paul Scherrer Institut, Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Villigen (Switzerland); Schibli, Roger [Paul Scherrer Institut, Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Villigen (Switzerland); ETH Zurich, Department of Chemistry and Applied Biosciences, Zurich (Switzerland)

    2017-04-15

    β-cells, located in the islets of the pancreas, are responsible for production and secretion of insulin and play a crucial role in blood sugar regulation. Pathologic β-cells often cause serious medical conditions affecting blood glucose level, which severely impact life quality and are life-threatening if untreated. With 347 million patients, diabetes is one of the most prevalent diseases, and will continue to be one of the largest socioeconomic challenges in the future. The diagnosis still relies mainly on indirect methods like blood sugar measurements. A non-invasive diagnostic imaging modality would allow direct evaluation of β-cell mass and would be a huge step towards personalized medicine. Hyperinsulinism is another serious condition caused by β-cells that excessively secrete insulin, like for instance β-cell hyperplasia and insulinomas. Treatment options with drugs are normally not curative, whereas curative procedures usually consist of the resection of affected regions for which, however, an exact localization of the foci is necessary. In this review, we describe potential tracers under development for targeting β-cells with focus on radiotracers for PET and SPECT imaging, which allow the non-invasive visualization of β-cells. We discuss either the advantages or limitations for the various tracers and modalities. This article concludes with an outlook on future developments and discuss the potential of new imaging probes including dual probes that utilize functionalities for both a radioactive and optical moiety as well as for theranostic applications. (orig.)

  5. In Vivo Bioluminescent Imaging (BLI: Noninvasive Visualization and Interrogation of Biological Processes in Living Animals

    Directory of Open Access Journals (Sweden)

    Steven Ripp

    2010-12-01

    Full Text Available In vivo bioluminescent imaging (BLI is increasingly being utilized as a method for modern biological research. This process, which involves the noninvasive interrogation of living animals using light emitted from luciferase-expressing bioreporter cells, has been applied to study a wide range of biomolecular functions such as gene function, drug discovery and development, cellular trafficking, protein-protein interactions, and especially tumorigenesis, cancer treatment, and disease progression. This article will review the various bioreporter/biosensor integrations of BLI and discuss how BLI is being applied towards a new visual understanding of biological processes within the living organism.

  6. In Vivo Bioluminescent Imaging (BLI): Noninvasive Visualization and Interrogation of Biological Processes in Living Animals

    Science.gov (United States)

    Close, Dan M.; Xu, Tingting; Sayler, Gary S.; Ripp, Steven

    2011-01-01

    In vivo bioluminescent imaging (BLI) is increasingly being utilized as a method for modern biological research. This process, which involves the noninvasive interrogation of living animals using light emitted from luciferase-expressing bioreporter cells, has been applied to study a wide range of biomolecular functions such as gene function, drug discovery and development, cellular trafficking, protein-protein interactions, and especially tumorigenesis, cancer treatment, and disease progression. This article will review the various bioreporter/biosensor integrations of BLI and discuss how BLI is being applied towards a new visual understanding of biological processes within the living organism. PMID:22346573

  7. Non-invasive long-term fluorescence live imaging of Tribolium castaneum embryos.

    Science.gov (United States)

    Strobl, Frederic; Stelzer, Ernst H K

    2014-06-01

    Insect development has contributed significantly to our understanding of metazoan development. However, most information has been obtained by analyzing a single species, the fruit fly Drosophila melanogaster. Embryonic development of the red flour beetle Tribolium castaneum differs fundamentally from that of Drosophila in aspects such as short-germ development, embryonic leg development, extensive extra-embryonic membrane formation and non-involuted head development. Although Tribolium has become the second most important insect model organism, previous live imaging attempts have addressed only specific questions and no long-term live imaging data of Tribolium embryogenesis have been available. By combining light sheet-based fluorescence microscopy with a novel mounting method, we achieved complete, continuous and non-invasive fluorescence live imaging of Tribolium embryogenesis at high spatiotemporal resolution. The embryos survived the 2-day or longer imaging process, developed into adults and produced fertile progeny. Our data document all morphogenetic processes from the rearrangement of the uniform blastoderm to the onset of regular muscular movement in the same embryo and in four orientations, contributing significantly to the understanding of Tribolium development. Furthermore, we created a comprehensive chronological table of Tribolium embryogenesis, integrating most previous work and providing a reference for future studies. Based on our observations, we provide evidence that serosa window closure and serosa opening, although deferred by more than 1 day, are linked. All our long-term imaging datasets are available as a resource for the community. Tribolium is only the second insect species, after Drosophila, for which non-invasive long-term fluorescence live imaging has been achieved.

  8. Molecular ultrasound imaging: current status and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, N. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California (United States); Needles, A. [Visualsonics, Toronto (Canada); Willmann, J.K., E-mail: willmann@stanford.ed [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California (United States)

    2010-07-15

    Targeted contrast-enhanced ultrasound (molecular ultrasound) is an emerging imaging strategy that combines ultrasound technology with novel molecularly-targeted ultrasound contrast agents for assessing biological processes at the molecular level. Molecular ultrasound contrast agents are nano- or micro-sized particles that are targeted to specific molecular markers by adding high-affinity binding ligands onto the surface of the particles. Following intravenous administration, these targeted ultrasound contrast agents accumulate at tissue sites overexpressing specific molecular markers, thereby enhancing the ultrasound imaging signal. High spatial and temporal resolution, real-time imaging, non-invasiveness, relatively low costs, lack of ionising irradiation and wide availability of ultrasound systems are advantages compared to other molecular imaging modalities. In this article we review current concepts and future directions of molecular ultrasound imaging, including different classes of molecular ultrasound contrast agents, ongoing technical developments of pre-clinical and clinical ultrasound systems, the potential of molecular ultrasound for imaging different diseases at the molecular level, and the translation of molecular ultrasound into the clinic.

  9. Localization of endocardial ectopic activity by means of noninvasive endocardial surface current density reconstruction

    Science.gov (United States)

    Lai, Dakun; Liu, Chenguang; Eggen, Michael D.; Iaizzo, Paul A.; He, Bin

    2011-07-01

    Localization of the source of cardiac ectopic activity has direct clinical benefits for determining the location of the corresponding ectopic focus. In this study, a recently developed current-density (CD)-based localization approach was experimentally evaluated in noninvasively localizing the origin of the cardiac ectopic activity from body-surface potential maps (BSPMs) in a well-controlled experimental setting. The cardiac ectopic activities were induced in four well-controlled intact pigs by single-site pacing at various sites within the left ventricle (LV). In each pacing study, the origin of the induced ectopic activity was localized by reconstructing the CD distribution on the endocardial surface of the LV from the measured BSPMs and compared with the estimated single moving dipole (SMD) solution and precise pacing site (PS). Over the 60 analyzed beats corresponding to ten pacing sites (six for each), the mean and standard deviation of the distance between the locations of maximum CD value and the corresponding PSs were 16.9 mm and 4.6 mm, respectively. In comparison, the averaged distance between the SMD locations and the corresponding PSs was slightly larger (18.4 ± 3.4 mm). The obtained CD distribution of activated sources extending from the stimulus site also showed high consistency with the endocardial potential maps estimated by a minimally invasive endocardial mapping system. The present experimental results suggest that the CD method is able to locate the approximate site of the origin of a cardiac ectopic activity, and that the distribution of the CD can portray the propagation of early activation of an ectopic beat.

  10. Non-invasive radiotracer imaging as a tool for drug development.

    Science.gov (United States)

    Gibson, R E; Burns, H D; Hamill, T G; Eng, W S; Francis, B E; Ryan, C

    2000-07-01

    Non-Invasive Radiotracer Imaging (NIRI) uses either short-lived positron-emitting isotopes, such as 11C and 18F, for Positron Emis ion Tomography (PET) or single photon emitting nuclides, e.g., 123I, which provide images using planar imaging or Single-Photon Emission Computed Tomography (SPECT). These high-resolution imaging modalities provide anatomical distribution and localization of radiolabeled drugs, which can be used to generate real time receptor occupancy and off-rate studies in humans. This can be accomplished by either isotopically labeling a potential new drug (usually with 11C), or indirectly by studying how the unlabelled drug inhibits specific radioligand binding in vivo. Competitive blockade studies can be accomplished using a radiolabeled analogue which binds to the site of interest, rather than a radiolabeled version of the potential drug. Imaging, particularly PET imaging, can be used to demonstrate the effect of a drug through a biochemical marker of processes such as glucose metabolism or blood flow. NIRI as a development tool in the pharmaceutical industry is gaining increased acceptance as its unique ability to provide such critical information in human subjects is recognized. This section will review recent examples that illustrate the utility of NIRI, principally PET, in drug development, and the potential of imaging advances in the development of cancer drugs and gene therapy. Finally, we provide a brief overview of the design of new radiotracers for novel targets.

  11. Quantitative whole body biodistribution of fluorescent-labeled agents by non-invasive tomographic imaging.

    Directory of Open Access Journals (Sweden)

    Kristine O Vasquez

    Full Text Available When small molecules or proteins are injected into live animals, their physical and chemical properties will significantly affect pharmacokinetics, tissue penetration, and the ultimate routes of metabolism and clearance. Fluorescence molecular tomography (FMT offers the ability to non-invasively image and quantify temporal changes in fluorescence throughout the major organ systems of living animals, in a manner analogous to traditional approaches with radiolabeled agents. This approach is best used with biotherapeutics (therapeutic antibodies, or other large proteins or large-scaffold drug-delivery vectors, that are minimally affected by low-level fluorophore conjugation. Application to small molecule drugs should take into account the significant impact of fluorophore labeling on size and physicochemical properties, however, the presents studies show that this technique is readily applied to small molecule agents developed for far-red (FR or near infrared (NIR imaging. Quantification by non-invasive FMT correlated well with both fluorescence from tissue homogenates as well as with planar (2D fluorescence reflectance imaging of excised intact organs (r²  =  0.996 and 0.969, respectively. Dynamic FMT imaging (multiple times from 0 to 24 h performed in live mice after the injection of four different FR/NIR-labeled agents, including immunoglobulin, 20-50 nm nanoparticles, a large vascular imaging agent, and a small molecule integrin antagonist, showed clear differences in the percentage of injected dose per gram of tissue (%ID/g in liver, kidney, and bladder signal. Nanoparticles and IgG1 favored liver over kidney signal, the small molecule integrin-binding agent favored rapid kidney and bladder clearance, and the vascular agent, showed both liver and kidney clearance. Further assessment of the volume of distribution of these agents by fluorescent volume added information regarding their biodistribution and highlighted the relatively poor

  12. A General Approach to the Non-Invasive Imaging of Transgenes Using Cis-Linked Herpes Simplex Virus Thymidine Kinase

    Directory of Open Access Journals (Sweden)

    Juri G. Tjuvajev

    1999-10-01

    Full Text Available Non-invasive imaging of gene expression opens new prospects for the study of transgenic animals and the implementation of genetically based therapies in patients. We have sought to establish a general paradigm to enable whole body non-invasive imaging of any transgene. We show that the expression and imaging of HSV1-tk (a marker gene can be used to monitor the expression of the LacZ gene (a second gene under the transcriptional control of a single promoter within a bicistronic unit that includes a type II internal ribosomal entry site. In cells bearing a single copy of the vector, the expression of the two genes is proportional and constant, both in vitro and in vivo. We demonstrate that non-invasive imaging of HSV1-tk gene accurately reflects the topology and activity of the other cis-linked transgene.

  13. [Noninvasive medical imaging system for tissue classification using RGB LED and micro-spectroscopy].

    Science.gov (United States)

    Yang, Bor-Wen; Lin, Yu-Min; Wang, Shih-Yuan; Ying, Shang-Ping

    2013-07-01

    As skin is the exterior organ of human body, cosmetic industry advances year by year. To reveal the details of skin tissue, threedimensional medical imaging is required. Based on the idea of "readout instead of write", a new scheme named spectral classification imaging (SCI) is proposed in the present study to reduce the invasiveness by applying the reflection spectra of the sample points for three-dimensional medical imaging. Broad-band light source and the spectrometer were employed to collect the spectra curves of scanned region, which were classified into several tissue types by their cross-correlations. A colorful tissue tomography can finally be obtained by filling in each image pixel the color indicating the corresponding tissue type. The lateral/longitudinal resolutions and penetration depth were analyzed to characterize the SCI system. The lateral resolution is based on the source's diffraction limit, the longitudinal resolution is by its depth-of-focus, and the penetration depth is equivalent to its skin depth. The imaging results of an amethyst of 0.6 mm (chi-direction) x 0.6 mm (y-direction) with a total of 120 x 120 pixels per frame and a guppy fish of 3.2 mm (chi-direction) x 2.4 mm (y-direction) of 160 x 120 pixels, are presented to show the image quality. The effects of the cross-correlation coefficient and the number of source wavelengths on the imaging results were explored. The value of cross-correlation threshold determines the required time for imaging, the resulted number of tissue groups, and the variety of tissue colors in the imaging result. Owing to its virtual noninvasiveness and easy configuration, the SCI system is highly promising for practical uses. RGB LEDs possess merits of broad bandwidth, low cost, long lifetime, small volume, and are ready to be integrated into a multi-color source module. Replacing the wide-band light source and the spectrometer module with a composite RGB LED with discrete wavelengths and a micro

  14. [Large left ventricular aneurysm after silent myocardial infarction. Documentation by serial non-invasive imaging].

    Science.gov (United States)

    Ritter, C; Beer, M; Weidemann, F; Strotmann, J; Müllges, W; Mohr, F W; Ertl, G; Hahn, D; Bauersachs, J

    2008-03-01

    A 60-year-old man had a workup for atypical angina. Noninvasive investigations, including computed tomography, showed no evidence for coronary artery disease. A few months later the patient was hospitalized because of severe epileptic seizures. Thyrotoxicosis was diagnosed and emergency thyroidectomy was performed. Two months after discharge the patient was again referred because of exercise-induced angina pectoris. Echocardiography and cardiac magnetic resonance imaging (MRI) showed a large aneurysm of the lateral wall of the left ventricle with a thrombus adhering to the wall. Coronary angiography and levocardiography confirmed the aneurysm and detected an occlusion of the distal part of the circumflex artery. Surgical aneurysm resection with thrombectomy and endoventricular circular plasty (Dor procedure) was performed without postoperative complications. Six months after surgery the patient was in good general condition without any angina. Follow-up echocardiography as well as cardiac MRI gave proof of an excellent postoperative result. Noninvasive preoperative diagnosis and documentation as well as postoperative monitoring with modern imaging modalities, such as echocardiography and MRI are of great value in patients with left ventricular aneurysm.

  15. Non-invasive in vivo imaging of calcium signaling in mice.

    Directory of Open Access Journals (Sweden)

    Kelly L Rogers

    Full Text Available Rapid and transient elevations of Ca(2+ within cellular microdomains play a critical role in the regulation of many signal transduction pathways. Described here is a genetic approach for non-invasive detection of localized Ca(2+ concentration ([Ca(2+] rises in live animals using bioluminescence imaging (BLI. Transgenic mice conditionally expressing the Ca(2+-sensitive bioluminescent reporter GFP-aequorin targeted to the mitochondrial matrix were studied in several experimental paradigms. Rapid [Ca(2+] rises inside the mitochondrial matrix could be readily detected during single-twitch muscle contractions. Whole body patterns of [Ca(2+] were monitored in freely moving mice and during epileptic seizures. Furthermore, variations in mitochondrial [Ca(2+] correlated to behavioral components of the sleep/wake cycle were observed during prolonged whole body recordings of newborn mice. This non-invasive imaging technique opens new avenues for the analysis of Ca(2+ signaling whenever whole body information in freely moving animals is desired, in particular during behavioral and developmental studies.

  16. Noninvasive imaging of internal muscle activities from multi-channel surface EMG recordings.

    Science.gov (United States)

    Zhang, Yingchun

    2013-01-01

    Surface Electromyogram (sEMG) technology provides a non-invasive way for rapid monitoring muscle activities, but its poor spatial resolution and specificity limit its application in clinic. To overcome these limitations, a noninvasive muscle activity imaging (MAI) approach has been developed and used to reconstruct internal muscle activities from multi-channel sEMG recordings. A realistic geometric hand model is developed from high-resolution MR images and a distributed bioelectric dipole source model is employed to describe the internal muscle activity space of the muscles. The finite element method and weighted minimum norm method are utilized solve the forward and inverse problems respectively involved in the proposed MAI technique. A series of computer simulations was conducted to test the performance of the proposed MAI approach. Results show that reconstruction results achieved by the MAI technique indeed provide us more detailed and dynamic information of internal muscle activities, which enhance our understanding of the mechanisms underlying the surface EMG recordings.

  17. Current and emerging techniques in gastrointestinal imaging

    Directory of Open Access Journals (Sweden)

    McSweeney S

    2010-01-01

    Full Text Available This review is devoted to current and emerging techniques in gastrointestinal (GI imaging. It is divided into three sections focusing on areas that are both interesting and challenging: imaging of the small bowel and appendix, imaging of the colon and rectum and finally liver and pancreas in the upper abdomen. The first section covers cross-sectional imaging of the small bowel using the techniques of multidetector computed tomography (MDCT (including CT enterography and magnetic resonance imaging (MRI. The evaluation of mesenteric ischemia and GI tract bleeding using MDCT angiography is also reviewed. Current imaging practice in the evaluation of appendix is also reviewed and illustrated. The second section reviews CT and MR colonography and imaging of the rectum. It describes CT virtual colonoscopy (CTVC with emphasis on the advantages and disadvantages of the technique with discussion of the role of CTVC in screening. The intriguing topic of MR colonography (MRC is also reviewed. Imaging of the rectum with emphasis on imaging of rectal cancer is described with the roles of CT, MR, endoluminal ultrasound and positron emission tomography scanning discussed. The final section reviews current and emerging techniques in liver imaging with the role of ultrasound including contrast ultrasound, MDCT and MR (including contrast agents discussed. The new developments and applications of imaging of pancreatic disease are discussed with emphasis on the role of MDCT and MRI with gadolinium. This review highlights the current role and advancement of imaging techniques with new diagnostic and prognostic information pertinent to gastrointestinal disease continuing to emerge.

  18. Non-invasive evaluation of arrhythmic risk in dilated cardiomyopathy:From imaging to electrocardiographic measures

    Institute of Scientific and Technical Information of China (English)

    Massimo; Iacoviello; Francesco; Monitillo

    2014-01-01

    Malignant ventricular arrhythmias are a major adverse event and worsen the prognosis of patients affected by ischemic and non-ischemic dilated cardiomyopathy.The main parameter currently used to stratify arrhythmic risk and guide decision making towards the implantation of a cardioverter defibrillator is the evaluation of the left ventricular ejection fraction.However,this strategy is characterized by several limitations and consequently additional parameters have been suggested in order to improve arrhythmic risk stratification.The aim of this review is to critically revise the prognostic significance of non-invasive diagnostic tools in order to better stratify the arrhythmic risk prognosis of dilated cardiomyopathy patients.

  19. Validation of Dynamic optical coherence tomography for non-invasive, in vivo microcirculation imaging of the skin

    DEFF Research Database (Denmark)

    Themstrup, L.; Welzel, Julia; Ciardo, Silvana

    2016-01-01

    Objectives: Dynamic optical coherence tomography (D-OCT) is an angiographic variation of OCT that non-invasively provides images of the in vivo microvasculature of the skin by combining conventional OCT images with flow data. The objective of this study was to investigate and report on the D-OCT ...

  20. MR and CT image fusion of the cervical spine: a noninvasive alternative to CT-myelography

    Science.gov (United States)

    Hu, Yangqiu; Mirza, Sohail K.; Jarvik, Jeffrey G.; Heagerty, Patrick J.; Haynor, David R.

    2005-04-01

    CT-Myelography (CTM) is routinely used for planning surgery for degenerative disease of the spine, but its invasive nature, significant potential morbidity, and high costs make a noninvasive substitute desirable. We report our work on evaluating CT and MR image fusion as an alternative to CTM. Because the spine is only piecewise rigid, a multi-rigid approach to the registration of spinal CT and MR images was developed (SPIE 2004), in which the spine on CT images is first segmented into separate vertebrae, each of which is then rigidly registered with the corresponding vertebra on MR images. The results are then blended to obtain fusion images. Since they contain information from both modalities, we hypothesized that fusion images would be equivalent to CTM. To test this we selected 34 patients who had undergone MRI and CTM for degenerative disease of the cervical spine, and used the multi-rigid approach to produce fused images. A clinical vignette for each patient was created and presented along with either CT/MR fusion images or CTM images. A group of spine surgeons are asked to formulate detailed surgical plans based on each set of images, and the surgical plans are compared. A similar study assessing diagnostic agreement is being performed with neuroradiologists, who also assess the accuracy of registration. Our work to date has demonstrated the feasibility of segmentation and multi-rigid fusion in clinical cases and the acceptability of the questionnaire to physicians. Preliminary analysis of one surgeon's and one neuroradiologist"s evaluation has been performed.

  1. Interventional magnetic resonance imaging - non-invasive imaging for interventions; Interventionelle Magnetresonanztomographie - nichtinvasive Bildgebung fuer Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Buecker, A.; Adam, G.; Neuerburg, J.M.; Glowinski, A.; Tacke, J.; Guenther, R.W. [Technische Hochschule Aachen (Germany). Medizinische Fakultaet

    2000-02-01

    As a prerequisite for MR-guidance of interventional procedures, instruments have to be well depicted in the MR image without obscuring or distorting the underlying anatomy. For non-vascular interventions the imaging speed has to be in the range of seconds while control of vascular interventions requires real time imaging speed. The imaging contrast has to be maintained as well as a high spatial resolution. Furthermore, sufficient patient access has to be provided by the MR scanner. Neither an ideal magnet nor the optimal single sequence are available to fulfill the above-mentioned criteria. The type of sequence - gradient echo versus spin echo - together with changing of the echo time and phase encording direction will ensure an appropriate size of the artifact and thereby of the appearance of the instrument in the MR image. The feasibility of non-vascular MR-guided interventions has been proved at field strengths ranging from 0.064 T to 1.5 T. Bone biopsies, soft tissue biopsies, drainages, and control of interstitial thermo- and cryotherapy have been reported. For vascular interventions, different real time MR strategies are currently under investigation. The development of dedicated catheters and guide wires has enabled MR-guided dilatations, stenting, placement of vena cava filters, and TIPS procedures. Considering the fast progress being made in this field, there can be no question that interventional MRI will become a well-accepted clinical tool offering potential advantages such as excellent soft tissue contrast, multiplanar imaging, flow measurements, high resolution imaging of vessel walls, and lack of ionizing radiation. (orig.) [German] Zur Durchfuehrung MR-gesteuerter Interventionen muessen interventionelle Instrumente gut sichtbar, aber ohne stoerende Artefakte darstellbar sein. Die Geschwindigkeit der Bilderstellung sollte fuer nichtvaskulaere Interventionen im Sekundenbereich liegen und fuer vaskulaere Interventionen Echtzeitbildgebung liefern. Weder

  2. Non-invasive imaging technics for diagnosis in children with surgical abdominal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Koonosuke; Sato, Yutaka; Shimoyamada, Hiroaki; Kim, Yoshitaka; Ishikawa, Misao (St. Marianna Univ. School of Medicine, Kawasaki, Kanagawa (Japan))

    1984-04-01

    The usefullness of non-invasive imaging technics namely CT and ultrasonography was evaluated in pediatric surgical abdominal diseases, under the category of A) inflammatory masses (10), B) biliary abnormalities (6), C) neoplasms (12), and D) blunt abdominal traumas (8), which were experienced at St. Marianna University Hospital from April 1978 to January 1982. According to the results of the clinical study, the plan of useful diagnostic approaches in each group by means of several imaging technics was outlined. In group A and B, ultrasonography is usually suffice for diagnosis and therapy planning, whereas in group C and D, in addition to the ultrasound, CT is sometimes required for evaluating the involvement of vascular structures and surrounding vital structures in cases of neoplasm, and coexisting injuries in the traumas.

  3. Non-invasive imaging for subclinical coronary atherosclerosis in patients with peripheral artery disease

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Kjaer, Andreas; Hesse, Birger

    2014-01-01

    Patients with peripheral artery disease are at high risk of coronary artery disease. An increasing number of studies show that a large proportion of patients with peripheral artery disease have significant coronary atherosclerosis, even in the absence of symptoms. Although the reported prevalence...... of subclinical coronary artery disease varies widely in patients with peripheral artery disease, it could include more than half of patients. No consensus exists to date on either the rationale for screening patients with peripheral artery disease for coronary atherosclerosis or the optimal algorithm and method...... for screening. An increasing number of imaging modalities are emerging that allow improved in vivo non-invasive characterization of atherosclerotic plaques. These novel imaging methods may lead to early detection of high-risk vulnerable plaques, enabling clinicians to improve risk stratification of patients...

  4. Quantitative non-invasive intracellular imaging of Plasmodium falciparum infected human erythrocytes

    Science.gov (United States)

    Edward, Kert; Farahi, Faramarz

    2014-05-01

    Malaria is a virulent pathological condition which results in over a million annual deaths. The parasitic agent Plasmodium falciparum has been extensively studied in connection with this epidemic but much remains unknown about its development inside the red blood cell host. Optical and fluorescence imaging are among the two most common procedures for investigating infected erythrocytes but both require the introduction of exogenous contrast agents. In this letter, we present a procedure for the non-invasive in situ imaging of malaria infected red blood cells. The procedure is based on the utilization of simultaneously acquired quantitative phase and independent topography data to extract intracellular information. Our method allows for the identification of the developmental stages of the parasite and facilitates in situ analysis of the morphological changes associated with the progression of this disease. This information may assist in the development of efficacious treatment therapies for this condition.

  5. Current Directions in Non-Invasive Low Intensity Electric Brain Stimulation for Depressive Disorder

    NARCIS (Netherlands)

    Schutter, D.J.L.G.; Sack, A.T.

    2014-01-01

    Non-invasive stimulation of the human brain to improve depressive symptoms is increasingly finding its way in clinical settings as a viable form of somatic treatment. Following successful modulation of neural excitability with subsequent antidepressant effects, neural polarization by administrating

  6. Current Directions in Non-Invasive Low Intensity Electric Brain Stimulation for Depressive Disorder

    NARCIS (Netherlands)

    Schutter, D.J.L.G.; Sack, A.T.

    2014-01-01

    Non-invasive stimulation of the human brain to improve depressive symptoms is increasingly finding its way in clinical settings as a viable form of somatic treatment. Following successful modulation of neural excitability with subsequent antidepressant effects, neural polarization by administrating

  7. Optimal Non-Invasive Fault Classification Model for Packaged Ceramic Tile Quality Monitoring Using MMW Imaging

    Science.gov (United States)

    Agarwal, Smriti; Singh, Dharmendra

    2016-04-01

    Millimeter wave (MMW) frequency has emerged as an efficient tool for different stand-off imaging applications. In this paper, we have dealt with a novel MMW imaging application, i.e., non-invasive packaged goods quality estimation for industrial quality monitoring applications. An active MMW imaging radar operating at 60 GHz has been ingeniously designed for concealed fault estimation. Ceramic tiles covered with commonly used packaging cardboard were used as concealed targets for undercover fault classification. A comparison of computer vision-based state-of-the-art feature extraction techniques, viz, discrete Fourier transform (DFT), wavelet transform (WT), principal component analysis (PCA), gray level co-occurrence texture (GLCM), and histogram of oriented gradient (HOG) has been done with respect to their efficient and differentiable feature vector generation capability for undercover target fault classification. An extensive number of experiments were performed with different ceramic tile fault configurations, viz., vertical crack, horizontal crack, random crack, diagonal crack along with the non-faulty tiles. Further, an independent algorithm validation was done demonstrating classification accuracy: 80, 86.67, 73.33, and 93.33 % for DFT, WT, PCA, GLCM, and HOG feature-based artificial neural network (ANN) classifier models, respectively. Classification results show good capability for HOG feature extraction technique towards non-destructive quality inspection with appreciably low false alarm as compared to other techniques. Thereby, a robust and optimal image feature-based neural network classification model has been proposed for non-invasive, automatic fault monitoring for a financially and commercially competent industrial growth.

  8. Optimal image reconstruction intervals for non-invasive coronary angiography with 64-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Leschka, Sebastian; Husmann, Lars; Desbiolles, Lotus M.; Boehm, Thomas; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Gaemperli, Oliver; Schepis, Tiziano; Koepfli, Pascal [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Center for Integrative Human Physiology, Zurich (Switzerland)

    2006-09-15

    The reconstruction intervals providing best image quality for non-invasive coronary angiography with 64-slice computed tomography (CT) were evaluated. Contrast-enhanced, retrospectively electrocardiography (ECG)-gated 64-slice CT coronary angiography was performed in 80 patients (47 male, 33 female; mean age 62.1{+-}10.6 years). Thirteen data sets were reconstructed in 5% increments from 20 to 80% of the R-R interval. Depending on the average heart rate during scanning, patients were grouped as <65 bpm (n=49) and {>=}65 bpm (n=31). Two blinded and independent readers assessed the image quality of each coronary segment with a diameter {>=}1.5 mm using the following scores: 1, no motion artifacts; 2, minor artifacts; 3, moderate artifacts; 4, severe artifacts; and 5, not evaluative. The average heart rate was 63.3{+-}13.1 bpm (range 38-102). Acceptable image quality (scores 1-3) was achieved in 99.1% of all coronary segments (1,162/1,172; mean image quality score 1.55{+-}0.77) in the best reconstruction interval. Best image quality was found at 60% and 65% of the R-R interval for all patients and for each heart rate subgroup, whereas motion artifacts occurred significantly more often (P<0.01) at other reconstruction intervals. At heart rates <65 bpm, acceptable image quality was found in all coronary segments at 60%. At heart rates {>=}65 bpm, the whole coronary artery tree could be visualized with acceptable image quality in 87% (27/31) of the patients at 60%, while ten segments in four patients were rated as non-diagnostic (scores 4-5) at any reconstruction interval. In conclusion, 64-slice CT coronary angiography provides best overall image quality in mid-diastole. At heart rates <65 bpm, diagnostic image quality of all coronary segments can be obtained at a single reconstruction interval of 60%. (orig.)

  9. Phase contrast X-ray imaging for the non-invasive detection of airway surfaces and lumen characteristics in mouse models of airway disease

    Energy Technology Data Exchange (ETDEWEB)

    Siu, K.K.W. [School of Physics, Monash University, Victoria 3800 (Australia); Monash Centre for Synchrotron Science, Monash University, Victoria 3800 (Australia)], E-mail: Karen.Siu@sync.monash.edu.au; Morgan, K.S.; Paganin, D.M. [School of Physics, Monash University, Victoria 3800 (Australia); Boucher, R. [CF Research and Treatment Center, University of North Carolina at Chapel Hill (United States); Uesugi, K.; Yagi, N. [SPring-8/JASRI, Hyogo 679-5198 (Japan); Parsons, D.W. [Department of Pulmonary Medicine, Women' s and Children' s Hospital, South Australia 5006 (Australia); Department of Paediatrics, University of Adelaide, South Australia, 5006 (Australia); Women' s and Children' s Health Research Institute, South Australia, 5006 (Australia)

    2008-12-15

    We seek to establish non-invasive imaging able to detect and measure aspects of the biology and physiology of surface fluids present on airways, in order to develop novel outcome measures able to validate the success of proposed genetic or pharmaceutical therapies for cystic fibrosis (CF) airway disease. Reduction of the thin airway surface liquid (ASL) is thought to be a central pathophysiological process in CF, causing reduced mucociliary clearance that supports ongoing infection and destruction of lung and airways. Current outcome measures in animal models, or humans, are insensitive to the small changes in ASL depth that ought to accompany successful airway therapies. Using phase contrast X-ray imaging (PCXI), we have directly examined the airway surfaces in the nasal airways and tracheas of anaesthetised mice, currently to a resolution of {approx}2 {mu}m. We have also achieved high resolution three-dimensional (3D) imaging of the small airways in mice using phase-contrast enhanced computed tomography (PC-CT) to elucidate the structure-function relationships produced by airway disease. As the resolution of these techniques improves they may permit non-invasive monitoring of changes in ASL depth with therapeutic intervention, and the use of 3D airway and imaging in monitoring of lung health and disease. Phase contrast imaging of airway surfaces has promise for diagnostic and monitoring options in animal models of CF, and the potential for future human airway imaging methodologies is also apparent.

  10. Using Non-Invasive Multi-Spectral Imaging to Quantitatively Assess Tissue Vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, A; Chernomordik, V; Riley, J; Hassan, M; Amyot, F; Dasgeb, B; Demos, S G; Pursley, R; Little, R; Yarchoan, R; Tao, Y; Gandjbakhche, A H

    2007-10-04

    This research describes a non-invasive, non-contact method used to quantitatively analyze the functional characteristics of tissue. Multi-spectral images collected at several near-infrared wavelengths are input into a mathematical optical skin model that considers the contributions from different analytes in the epidermis and dermis skin layers. Through a reconstruction algorithm, we can quantify the percent of blood in a given area of tissue and the fraction of that blood that is oxygenated. Imaging normal tissue confirms previously reported values for the percent of blood in tissue and the percent of blood that is oxygenated in tissue and surrounding vasculature, for the normal state and when ischemia is induced. This methodology has been applied to assess vascular Kaposi's sarcoma lesions and the surrounding tissue before and during experimental therapies. The multi-spectral imaging technique has been combined with laser Doppler imaging to gain additional information. Results indicate that these techniques are able to provide quantitative and functional information about tissue changes during experimental drug therapy and investigate progression of disease before changes are visibly apparent, suggesting a potential for them to be used as complementary imaging techniques to clinical assessment.

  11. Single-beat noninvasive imaging of ventricular endocardial and epicardial activation in patients undergoing CRT.

    Directory of Open Access Journals (Sweden)

    Thomas Berger

    Full Text Available BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF undergoing CRT and in ten patients without structural heart disease (control group. NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05. CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05. CONCLUSIONS/SIGNIFICANCE: Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming.

  12. Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

    Science.gov (United States)

    Berger, Thomas; Pfeifer, Bernhard; Hanser, Friedrich F.; Hintringer, Florian; Fischer, Gerald; Netzer, Michael; Trieb, Thomas; Stuehlinger, Markus; Dichtl, Wolfgang; Baumgartner, Christian; Pachinger, Otmar; Seger, Michael

    2011-01-01

    Background Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. Methodology/Principal Findings NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV) pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05). CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05). Conclusions/Significance Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming. PMID:21298045

  13. Molecular imaging: current status and emerging strategies

    Energy Technology Data Exchange (ETDEWEB)

    Pysz, M.A. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States); Gambhir, S.S. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States); Departments of Bioengineering and Materials Science and Engineering, Stanford University, Stanford, CA (United States); Willmann, J.K., E-mail: willmann@stanford.ed [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States)

    2010-07-15

    In vivo molecular imaging has a great potential to impact medicine by detecting diseases in early stages (screening), identifying extent of disease, selecting disease- and patient-specific treatment (personalized medicine), applying a directed or targeted therapy, and measuring molecular-specific effects of treatment. Current clinical molecular imaging approaches primarily use positron-emission tomography (PET) or single photon-emission computed tomography (SPECT)-based techniques. In ongoing preclinical research, novel molecular targets of different diseases are identified and, sophisticated and multifunctional contrast agents for imaging these molecular targets are developed along with new technologies and instrumentation for multi-modality molecular imaging. Contrast-enhanced molecular ultrasound (US) with molecularly-targeted contrast microbubbles is explored as a clinically translatable molecular imaging strategy for screening, diagnosing, and monitoring diseases at the molecular level. Optical imaging with fluorescent molecular probes and US imaging with molecularly-targeted microbubbles are attractive strategies as they provide real-time imaging, are relatively inexpensive, produce images with high spatial resolution, and do not involve exposure to ionizing irradiation. Raman spectroscopy/microscopy has emerged as a molecular optical imaging strategy for ultrasensitive detection of multiple biomolecules/biochemicals with both in vivo and ex vivo versatility. Photoacoustic imaging is a hybrid of optical and US techniques involving optically-excitable molecularly-targeted contrast agents and quantitative detection of resulting oscillatory contrast agent movement with US. Current preclinical findings and advances in instrumentation, such as endoscopes and microcatheters, suggest that these molecular imaging methods have numerous potential clinical applications and will be translated into clinical use in the near future.

  14. Genitourinary imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    O′ Donoghue P

    2010-01-01

    Full Text Available This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT and magnetic resonance (MR in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  15. Genitourinary imaging: current and emerging applications.

    Science.gov (United States)

    O' Donoghue, P M; McSweeney, S E; Jhaveri, K

    2010-01-01

    This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT) and magnetic resonance (MR) in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  16. Noninvasive Vascular Displacement Estimation for Relative Elastic Modulus Reconstruction in Transversal Imaging Planes

    Directory of Open Access Journals (Sweden)

    Chris L. de Korte

    2013-03-01

    Full Text Available Atherosclerotic plaque rupture can initiate stroke or myocardial infarction. Lipid-rich plaques with thin fibrous caps have a higher risk to rupture than fibrotic plaques. Elastic moduli differ for lipid-rich and fibrous tissue and can be reconstructed using tissue displacements estimated from intravascular ultrasound radiofrequency (RF data acquisitions. This study investigated if modulus reconstruction is possible for noninvasive RF acquisitions of vessels in transverse imaging planes using an iterative 2D cross-correlation based displacement estimation algorithm. Furthermore, since it is known that displacements can be improved by compounding of displacements estimated at various beam steering angles, we compared the performance of the modulus reconstruction with and without compounding. For the comparison, simulated and experimental RF data were generated of various vessel-mimicking phantoms. Reconstruction errors were less than 10%, which seems adequate for distinguishing lipid-rich from fibrous tissue. Compounding outperformed single-angle reconstruction: the interquartile range of the reconstructed moduli for the various homogeneous phantom layers was approximately two times smaller. Additionally, the estimated lateral displacements were a factor of 2–3 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding.

  17. Non-invasive structural and biomechanical imaging of the developing embryos (Conference Presentation)

    Science.gov (United States)

    Zhang, Jitao; Wu, Chen; Raghunathan, Raksha; Larin, Kirill V.; Scarcelli, Giuliano

    2017-02-01

    Embryos undergo dramatic changes in size, shape, and mechanical properties during development, which is regulated by both genetic and environmental factors. Quantifying mechanical properties of different embryonic tissues may represent good metrics for the embryonic health and proper development. Alternations and structure coupled with biomechanical information may provide a way for early diagnosis and drug treatment of various congenital diseases. Many methods have been developed to determine the mechanical properties of the embryo, such as atomic force microscopy (AFM), ultrasound elastography (UE), and optical coherent elastography (OCE). However, AFM is invasive and time-consuming. While UE and OCE are both non-invasive methods, the spatial resolutions are limited to mm to sub-mm, which is not enough to observe the details inside the embryo. Brillouin microscopy can potentially enable non-invasive measurement of the mechanical properties of a sample by measuring the spectra of acoustically induced light scattering therein. It has fast speed ( 0.1 second per point) and high resolution (sub-micron), and thus has been widely investigated for biomedical application, such as single cell and tissue. In this work, we utilized this technique to characterize the mechanical property of an embryo. A 2D elasticity imaging of the whole body of an E8 embryo was acquired by a Brillouin microscopy, and the stiffness changes between different organs (such as brain, heart, and spine) were shown. The elasticity maps were correlated with structural information provided by OCT.

  18. A Kalman Filtering and Nonlinear Penalty Regression Approach for Noninvasive Anemia Detection with Palpebral Conjunctiva Images

    Directory of Open Access Journals (Sweden)

    Yi-Ming Chen

    2017-01-01

    Full Text Available Noninvasive medical procedures are usually preferable to their invasive counterparts in the medical community. Anemia examining through the palpebral conjunctiva is a convenient noninvasive procedure. The procedure can be automated to reduce the medical cost. We propose an anemia examining approach by using a Kalman filter (KF and a regression method. The traditional KF is often used in time-dependent applications. Here, we modified the traditional KF for the time-independent data in medical applications. We simply compute the mean value of the red component of the palpebral conjunctiva image as our recognition feature and use a penalty regression algorithm to find a nonlinear curve that best fits the data of feature values and the corresponding levels of hemoglobin (Hb concentration. To evaluate the proposed approach and several relevant approaches, we propose a risk evaluation scheme, where the entire Hb spectrum is divided into high-risk, low-risk, and doubtful intervals for anemia. The doubtful interval contains the Hb threshold, say 11 g/dL, separating anemia and nonanemia. A suspect sample is the sample falling in the doubtful interval. For the anemia screening purpose, we would like to have as less suspect samples as possible. The experimental results show that the modified KF reduces the number of suspect samples significantly for all the approaches considered here.

  19. Noninvasive real-time fluorescence imaging of the lymphatic uptake of BSA-IRDye 680 conjugate administered subcutaneously in mice.

    Science.gov (United States)

    Wu, Fang; Bhansali, Suraj G; Tamhane, Mitalee; Kumar, Rajiv; Vathy, Lisa A; Ding, Hong; Yong, Ken-Tye; Bergey, Earl J; Prasad, Paras N; Morris, Marilyn E

    2012-05-01

    The goal of our studies was to determine lymphatic uptake of bovine serum albumin (BSA) using real-time noninvasive fluorescence imaging. BSA labeled with near-infrared dye (IRDye) 680 was used as a model protein-dye conjugate. The conjugation of BSA with IRDye 680 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Size-exclusion high-performance liquid chromatography and SDS-PAGE demonstrated that the IRDye 680-labeled BSA conjugate in the lymph node (LN) homogenate samples was stable at physiological temperature (37°C) for at least 5 days. Whole-body noninvasive optical imaging of hairless SKH-1 mice was performed after subcutaneous (s.c.) injection (dose = 0.1 mg/kg) into the front footpad. Noninvasive fluorescence imaging demonstrated that BSA-IRDye 680 conjugates were dynamically taken up by the lymphatic system, accumulated in the axillary LNs and then cleared, indicating that lymphatic transport plays a role in the absorption of BSA. Ex vivo tissue imaging of LN homogenates provided confirmatory data with respect to the uptake of fluorescent-labeled BSA determined by in vivo imaging. Noninvasive real-time imaging of LNs provides a novel tool for evaluating uptake and accumulation of fluorescent-labeled proteins by the lymphatic system after s.c. injection in a mouse model.

  20. Noninvasive remote activation of the ventral midbrain by transcranial direct current stimulation of prefrontal cortex

    OpenAIRE

    Chib, V. S.; Yun, K; Takahashi, H; Shimojo, S.

    2013-01-01

    The midbrain lies deep within the brain and has an important role in reward, motivation, movement and the pathophysiology of various neuropsychiatric disorders such as Parkinson's disease, schizophrenia, depression and addiction. To date, the primary means of acting on this region has been with pharmacological interventions or implanted electrodes. Here we introduce a new noninvasive brain stimulation technique that exploits the highly interconnected nature of the midbrain and prefrontal cort...

  1. Superresolution imaging: a survey of current techniques

    Science.gov (United States)

    Cristóbal, G.; Gil, E.; Šroubek, F.; Flusser, J.; Miravet, C.; Rodríguez, F. B.

    2008-08-01

    Imaging plays a key role in many diverse areas of application, such as astronomy, remote sensing, microscopy, and tomography. Owing to imperfections of measuring devices (e.g., optical degradations, limited size of sensors) and instability of the observed scene (e.g., object motion, media turbulence), acquired images can be indistinct, noisy, and may exhibit insuffcient spatial and temporal resolution. In particular, several external effects blur images. Techniques for recovering the original image include blind deconvolution (to remove blur) and superresolution (SR). The stability of these methods depends on having more than one image of the same frame. Differences between images are necessary to provide new information, but they can be almost unperceivable. State-of-the-art SR techniques achieve remarkable results in resolution enhancement by estimating the subpixel shifts between images, but they lack any apparatus for calculating the blurs. In this paper, after introducing a review of current SR techniques we describe two recently developed SR methods by the authors. First, we introduce a variational method that minimizes a regularized energy function with respect to the high resolution image and blurs. In this way we establish a unifying way to simultaneously estimate the blurs and the high resolution image. By estimating blurs we automatically estimate shifts with subpixel accuracy, which is inherent for good SR performance. Second, an innovative learning-based algorithm using a neural architecture for SR is described. Comparative experiments on real data illustrate the robustness and utilization of both methods.

  2. Gastrointestinal tract imaging in children: current techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hiorns, Melanie P. [Great Ormond Street Hospital for Children, Radiology Department, London (United Kingdom)

    2011-01-15

    Imaging of the gastrointestinal (GI) tract in children continues to evolve, with new techniques, both radiological and non-radiological, being added to the repertoire. This article provides a summary of current imaging techniques of the GI tract (primarily the upper GI tract) and the relationship between those techniques. It covers the upper GI series and other contrast studies, US, CT and MRI. Note is also made of the contribution now made by capsule endoscopy (CE). Abdominal emergency imaging is not covered in this article. (orig.)

  3. Noninvasive Imaging of Hypoxia-Inducible Factor-1α Gene Therapy for Myocardial Ischemia

    Science.gov (United States)

    Chen, Ian Y.; Gheysens, Olivier; Li, Zongjin; Rasooly, Julia A.; Wang, Qian; Paulmurugan, Ramasamy; Rosenberg, Jarrett; Rodriguez-Porcel, Martin; Willmann, Juergen K.; Wang, David S.; Contag, Christopher H.; Robbins, Robert C.; Wu, Joseph C.

    2013-01-01

    Abstract Hypoxia-inducible factor-1 alpha (HIF-1α) gene therapy holds great promise for the treatment of myocardial ischemia. Both preclinical and clinical evaluations of this therapy are underway and can benefit from a vector strategy that allows noninvasive assessment of HIF-1α expression as an objective measure of gene delivery. We have developed a novel bidirectional plasmid vector (pcTnT-HIF-1α-VP2-TSTA-fluc), which employs the cardiac troponin T (cTnT) promoter in conjunction with a two-step transcriptional amplification (TSTA) system to drive the linked expression of a recombinant HIF-1α gene (HIF-1α-VP2) and the firefly luciferase gene (fluc). The firefly luciferase (FLuc) activity serves as a surrogate for HIF-1α-VP2 expression, and can be noninvasively assessed in mice using bioluminescence imaging after vector delivery. Transfection of cultured HL-1 cardiomyocytes with pcTnT-HIF-1α-VP2-TSTA-fluc led to a strong correlation between FLuc and HIF-1α-dependent vascular endothelial growth factor expression (r2=0.88). Intramyocardial delivery of pcTnT-HIF-1α-VP2-TSTA-fluc into infarcted mouse myocardium led to persistent HIF-1α-VP2 expression for 4 weeks, even though it improved neither CD31+ microvessel density nor echocardiographically determined left ventricular systolic function. These results lend support to recent findings of suboptimal efficacy associated with plasmid-mediated HIF-1α therapy. The imaging techniques developed herein should be useful for further optimizing HIF-1α-VP2 therapy in preclinical models of myocardial ischemia. PMID:23937265

  4. Radiation exposure of cardiac sonographers working in an academic noninvasive cardiovascular imaging laboratory.

    Science.gov (United States)

    Velez, Michael R; Orsinelli, Maryellen H; Orsinelli, David A

    2017-09-24

    Exposure to workplace radiation among cardiac sonographers has been felt to be low, and patient-related sources have been considered negligible. Sonographers may be exposed to radiation from patient emitted sources as well as external sources in interventional laboratories. This study quantified radiation exposure to cardiac sonographers. Cardiac sonographers, vascular imaging technologists, exercise physiologists, noninvasive nursing staff, and CT/MRI technologists were provided body dosimeter badges. Sonographers were provided dosimeter rings for their scanning hands. Radiation exposure was quantified from the dosimeter data, reported in millirems (mrem) for deep, eye, and shallow exposure, as well as shallow exposure data from the rings. Data were prospectively collected for 63 employees over a 12-month period and retrospectively analyzed. The mean annual deep body exposure in sonographers was 8.2 mrem/year, shallow exposure 9.8 mrem/year, eye exposure 8.5 mrem/year, and ring exposure 207 mrem/year. There was a significant difference between body and ring exposure (P = .0002). When comparing exposure data between the vascular imaging technologists, CT/MRI technologists, noninvasive nursing staff, and the cardiac sonographers, there were no statistical differences (P > .23). Exercise physiologists had significantly higher exposure compared to sonographers (P exposure is low, cardiac sonographers are exposed to workplace radiation, most likely from patient emitted radiation. The finding that radiation exposure from rings exceeded body exposure supports this conclusion. Continued education and assessment of work flow practices should be employed to minimize staff radiation exposure. © 2017, Wiley Periodicals, Inc.

  5. Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds.

    Science.gov (United States)

    Jerem, Paul; Herborn, Katherine; McCafferty, Dominic; McKeegan, Dorothy; Nager, Ruedi

    2015-11-06

    Stress, a central concept in biology, describes a suite of emergency responses to challenges. Among other responses, stress leads to a change in blood flow that results in a net influx of blood to key organs and an increase in core temperature. This stress-induced hyperthermia is used to assess stress. However, measuring core temperature is invasive. As blood flow is redirected to the core, the periphery of the body can cool. This paper describes a protocol where peripheral body temperature is measured non-invasively in wild blue tits (Cyanistes caeruleus) using infrared thermography. In the field we created a set-up bringing the birds to an ideal position in front of the camera by using a baited box. The camera takes a short thermal video recording of the undisturbed bird before applying a mild stressor (closing the box and therefore capturing the bird), and the bird's response to being trapped is recorded. The bare skin of the eye-region is the warmest area in the image. This allows an automated extraction of the maximum eye-region temperature from each image frame, followed by further steps of manual data filtering removing the most common sources of errors (motion blur, blinking). This protocol provides a time series of eye-region temperature with a fine temporal resolution that allows us to study the dynamics of the stress response non-invasively. Further work needs to demonstrate the usefulness of the method to assess stress, for instance to investigate whether eye-region temperature response is proportional to the strength of the stressor. If this can be confirmed, it will provide a valuable alternative method of stress assessment in animals and will be useful to a wide range of researchers from ecologists, conservation biologists, physiologists to animal welfare researchers.

  6. Rationale and methods of the integrated biomarker and imaging study (IBIS): combining invasive and non-invasive imaging with biomarkers to detect subclinical atherosclerosis and assess coronary lesion biology.

    Science.gov (United States)

    Van Mieghem, Carlos A G; Bruining, Nico; Schaar, Johannes A; McFadden, Eugene; Mollet, Nico; Cademartiri, Filippo; Mastik, Frits; Ligthart, Jurgen M R; Granillo, Gaston A Rodriguez; Valgimigli, Marco; Sianos, Georgios; van der Giessen, Willem J; Backx, Bianca; Morel, Marie-Angele M; Van Es, Gerrit-Anne; Sawyer, Jonathon D; Kaplow, June; Zalewski, Andrew; van der Steen, Anton F W; de Feyter, Pim; Serruys, Patrick W

    2005-08-01

    Death or myocardial infarction, the most serious clinical consequences of atherosclerosis, often result from plaque rupture at non-flow limiting lesions. Current diagnostic imaging with coronary angiography only detects large plaques that already impinge on the lumen and cannot accurately identify those that have a propensity to cause unheralded events. Accurate evaluation of the composition or of the biomechanical characteristics of plaques with invasive or non-invasive methods, alone or in conjunction with assessment of circulating biomarkers, could help identify high-risk patients, thus providing the rationale for aggressive treatments in order to reduce future clinical events. The IBIS (Integrated Biomarker and Imaging Study) study is a prospective, single-center, non-randomized, observational study conducted in Rotterdam. The aim of the IBIS study is to evaluate both invasive (quantitative coronary angiography, intravascular ultrasound (IVUS) and palpography) and non-invasive (multislice spiral computed tomography) imaging techniques to characterize non-flow limiting coronary lesions. In addition, multiple classical and novel biomarkers will be measured and their levels correlated with the results of the different imaging techniques. A minimum of 85 patients up to a maximum of 120 patients will be included. This paper describes the study protocol and methodological solutions that have been devised for the purpose of comparisons among several imaging modalities. It outlines the analyses that will be performed to compare invasive and non-invasive imaging techniques in conjunction with multiple biomarkers to characterize non-flow limiting subclinical coronary lesions.

  7. Multifunctional single beam acoustic tweezer for non-invasive cell/organism manipulation and tissue imaging

    Science.gov (United States)

    Lam, Kwok Ho; Li, Ying; Li, Yang; Lim, Hae Gyun; Zhou, Qifa; Shung, Koping Kirk

    2016-11-01

    Non-contact precise manipulation of single microparticles, cells, and organisms has attracted considerable interest in biophysics and biomedical engineering. Similar to optical tweezers, acoustic tweezers have been proposed to be capable of manipulating microparticles and even cells. Although there have been concerted efforts to develop tools for non-contact manipulation, no alternative to complex, unifunctional tweezer has yet been found. Here we report a simple, low-cost, multifunctional single beam acoustic tweezer (SBAT) that is capable of manipulating an individual micrometer scale non-spherical cell at Rayleigh regime and even a single millimeter scale organism at Mie regime, and imaging tissue as well. We experimentally demonstrate that the SBAT with an ultralow f-number (f# = focal length/aperture size) could manipulate an individual red blood cell and a single 1.6 mm-diameter fertilized Zebrafish egg, respectively. Besides, in vitro rat aorta images were collected successfully at dynamic foci in which the lumen and the outer surface of the aorta could be clearly seen. With the ultralow f-number, the SBAT offers the combination of large acoustic radiation force and narrow beam width, leading to strong trapping and high-resolution imaging capabilities. These attributes enable the feasibility of using a single acoustic device to perform non-invasive multi-functions simultaneously for biomedical and biophysical applications.

  8. Non-invasive pre-clinical MR imaging of prostate tumor hypoxia for radiation therapy prognosis

    Directory of Open Access Journals (Sweden)

    Derek White

    2014-03-01

    Full Text Available Purpose: To investigate the usefulness of Oxygen-Enhanced Magnetic Resonance Imaging (OE-MRI changes in signal intensity related to oxygen challenge for predicting tumor response to radiation therapy.Methods: Dynamic MR signal changes were acquired using Varian 4.7T small animal MR scanner prior to image-guided radiation therapy (IGRT of small (n = 6 and large subcutaneous (n = 5 prostate tumors in adult male rats. An interleaved blood-oxygen level dependent (BOLD and tissue-oxygen level dependent (TOLD data acquisition or (IBT was performed using a baseline of medical air as positive control and using medical oxygen as a breathing challenge. BOLD used a 2-D multi-slice spoiled gradient-echo with multi-echo sequence. TOLD used a 2-D multi-slice spoiled gradient-echo sequence. Voxel changes in signal intensity were determined by a correlation coefficient mapping technique. Irradiation technique planned consisted of 1F × 15 Gy AP/PA or 2F × 7.5 Gy AP/PA to the gross tumor volume (GTV. Tumor growth measurements were recorded over time to assess the response to IGRT.Results: BOLD and TOLD signals variously illustrated positive or negative impulse responses in the tumor ROI due to inhaling medical oxygen. Correlation coefficient mapping demonstrated heterogeneity in tumors after inhaling medical oxygen. BOLD and TOLD signals exhibited increased changes in signal intensities after the first fraction of dose. Multi-fractionation had minimum effect until the second fraction of dose was applied. Tumor growth delays were observed when inhaling medical oxygen during IGRT.Conclusion: OE-MRI is a non-invasive imaging modality that can provide insight to the oxygen status of tumors. Observed increase percent changes in BOLD and TOLD signal intensities after the first fraction of dose suggest tumors experienced reoxygenation. OE-MRI could be used for predicting tumor response to IGRT when using medical oxygen for increasing GTV radiosensitivity, suggesting

  9. Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

    NARCIS (Netherlands)

    Hachamovitch, R.; Nutter, B.; Hlatky, M.A.; Shaw, L.J.; Ridner, M.L.; Dorbala, S.; Beanlands, R.S.; Chow, B.J.; Branscomb, E.; Chareonthaitawee, P.; Weigold, W.G.; Voros, S.; Abbara, S.; Yasuda, T.; Jacobs, J.E.; Lesser, J.; Berman, D.S.; Thomson, L.E.; Raman, S.; Heller, G.V.; Schussheim, A.; Brunken, R.; Williams, K.A.; Farkas, S.; Delbeke, D.; Schoepf, U.J.; Reichek, N.; Rabinowitz, S.; Sigman, S.R.; Patterson, R.; Corn, C.R.; White, R.; Kazerooni, E.; Corbett, J.; Bokhari, S.; Machac, J.; Guarneri, E.; Borges-Neto, S.; Millstine, J.W.; Caldwell, J.; Arrighi, J.; Hoffmann, U.; Budoff, M.; Lima, J.; Johnson, J.R.; Johnson, B.; Gaber, M.; Williams, J.A.; Foster, C.; Hainer, J.; Carli, M.F. Di

    2012-01-01

    OBJECTIVES: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS: We assessed the 90-day post

  10. Confocal Fluorescence Imaging Enables Noninvasive Quantitative Assessment of Host Cell Populations In Vivo Following Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Soumya Mitra, Oleg Mironov, Thomas H. Foster

    2012-01-01

    Full Text Available We report the use of optical imaging strategies to noninvasively examine photosensitizer distribution and physiological and host responses to 2-[1-hexyloxyethyl]-2 devinyl pyropheophorbide-a (HPPH-mediated photodynamic therapy (PDT of EMT6 tumors established in the ears of BALB/c mice. 24 h following intravenous (IV administration of 1 μmol kg-1 HPPH, wide-field fluorescence imaging reveals tumor selectivity with an approximately 2-3-fold differential between tumor and adjacent normal tissue. Confocal microscopy demonstrates a relatively homogeneous intratumor HPPH distribution. Labeling of host cells using fluorophore-conjugated antibodies allowed the visualization of Gr1+/CD11b+ leukocytes and major histocompatibility complex class II (MHC-II+ cells in vivo. Imaging of the treated site at different time-points following irradiation shows significant and rapid increases in Gr1+ cells in response to therapy. The maximum accumulation of Gr1+ cells is found at 24 h post-irradiation, followed by a decrease at the 48 h time-point. Using IV-injected FITC-conjugated dextran as a fluorescent perfusion marker, we imaged tissue perfusion at different times post-irradiation and found that the reduced Gr1+ cell density at 48 h correlated strongly with functional damage to the vasculature as reported via decreased perfusion status. Dual color confocal imaging experiments demonstrates that about 90% of the anti-Gr1 cell population co-localized with anti-CD11b labeling, thus indicating that majority of the Gr1-labeled cells were neutrophils. At 24 h post-PDT, an approximately 2-fold increase in MHC-II+ cells relative to untreated control is also observed. Co-localization analysis reveals an increase in the fraction of Gr1+ cells expressing MHC-II, suggesting that HPPH-PDT is stimulating neutrophils to express an antigen-presenting phenotype.

  11. Noninvasive measurement of burn wound depth applying infrared thermal imaging (Conference Presentation)

    Science.gov (United States)

    Jaspers, Mariëlle E.; Maltha, Ilse M.; Klaessens, John H.; Vet, Henrica C.; Verdaasdonk, Rudolf M.; Zuijlen, Paul P.

    2016-02-01

    In burn wounds early discrimination between the different depths plays an important role in the treatment strategy. The remaining vasculature in the wound determines its healing potential. Non-invasive measurement tools that can identify the vascularization are therefore considered to be of high diagnostic importance. Thermography is a non-invasive technique that can accurately measure the temperature distribution over a large skin or tissue area, the temperature is a measure of the perfusion of that area. The aim of this study was to investigate the clinimetric properties (i.e. reliability and validity) of thermography for measuring burn wound depth. In a cross-sectional study with 50 burn wounds of 35 patients, the inter-observer reliability and the validity between thermography and Laser Doppler Imaging were studied. With ROC curve analyses the ΔT cut-off point for different burn wound depths were determined. The inter-observer reliability, expressed by an intra-class correlation coefficient of 0.99, was found to be excellent. In terms of validity, a ΔT cut-off point of 0.96°C (sensitivity 71%; specificity 79%) differentiates between a superficial partial-thickness and deep partial-thickness burn. A ΔT cut-off point of -0.80°C (sensitivity 70%; specificity 74%) could differentiate between a deep partial-thickness and a full-thickness burn wound. This study demonstrates that thermography is a reliable method in the assessment of burn wound depths. In addition, thermography was reasonably able to discriminate among different burn wound depths, indicating its potential use as a diagnostic tool in clinical burn practice.

  12. Non-Invasive Detection of Lung Inflammation by Near-Infrared Fluorescence Imaging Using Bimodal Liposomes.

    Science.gov (United States)

    Desu, Hari R; Wood, George C; Thoma, Laura A

    2016-01-01

    Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome results in respiratory obstruction and severe lung inflammation. Critical characteristics of ALI are alveolar edema, infiltration of leukocytes (neutrophils and monocytes), release of pro-inflammatory cytokines and chemokines into broncho-alveolar lavage fluid, and activation of integrin receptors. The purpose of the study was to demonstrate non-invasive detection of lung inflammation using integrin receptor targeted fluorescence liposomes. An inflammation similar to that observed in ALI was elicited in rodents by intra-tracheal instillation of interleukin-1beta (IL-1beta). Cyclic arginine glycine-(D)-aspartic acid-peptide (cRGD-peptide) grafted fluorescence liposomes were administered to ALI induced male Sprague-Dawley rats for targeting lung integrin receptors. Near-infrared fluorescence imaging (NIRFI) was applied for visualization and quantitation of lung inflammation. NIRFI signals were correlated with inflammatory cellular and biochemical markers of lungs. A positive correlation was observed between NIRF signals and lung inflammation markers. Compared to control group, an intense NIRF signal was observed in ALI induced rats in the window 6-24 h post-IL-1beta instillation. Interaction of integrin receptors with targeted liposomes was assumed to contribute to intense NIRF signal. RT-PCR studies showed an elevated lung expression of alphavbeta5 integrin receptors, 12 h post-IL-1beta instillation. In vitro studies demonstrated integrin receptor specificity of targeted liposomes. These targeted liposomes showed binding to alphavbeta5 integrin receptors expressed on alveolar cells. Non-invasive detection of lung inflammation was demonstrated using a combination of integrin receptor targeting and NIRFI.

  13. Non-Invasive In Vivo Imaging and Quantification of Tumor Growth and Metastasis in Rats Using Cells Expressing Far-Red Fluorescence Protein.

    Directory of Open Access Journals (Sweden)

    Jon Christensen

    Full Text Available Non-invasive in vivo imaging is emerging as an important tool for basic and preclinical research. Near-infrared (NIR fluorescence dyes and probes have been used for non-invasive optical imaging since in the NIR region absorption and auto fluorescence by body tissue is low, thus permitting for greater penetration depths and high signal to noise ratio. Currently, cell tracking systems rely on labeling cells prior to injection or administering probes targeting the cell population of choice right before imaging. These approaches do not enable imaging of tumor growth, as the cell label is diluted during cell division. In this study we have developed cell lines stably expressing the far-red fluorescence protein E2-Crimson, thus enabling continuous detection and quantification of tumor growth. In a xenograft rat model, we show that E2-Crimson expressing cells can be detected over a 5 week period using optical imaging. Fluorescence intensities correlated with tumor volume and weight and allowed for a reliable and robust quantification of the entire tumor compartment. Using a novel injection regime, the seeding of MDA-MB-231 breast cancer cells in the lungs in a rat model was established and verified.

  14. Non-Invasive In Vivo Imaging and Quantification of Tumor Growth and Metastasis in Rats Using Cells Expressing Far-Red Fluorescence Protein.

    Science.gov (United States)

    Christensen, Jon; Vonwil, Daniel; Shastri, V Prasad

    2015-01-01

    Non-invasive in vivo imaging is emerging as an important tool for basic and preclinical research. Near-infrared (NIR) fluorescence dyes and probes have been used for non-invasive optical imaging since in the NIR region absorption and auto fluorescence by body tissue is low, thus permitting for greater penetration depths and high signal to noise ratio. Currently, cell tracking systems rely on labeling cells prior to injection or administering probes targeting the cell population of choice right before imaging. These approaches do not enable imaging of tumor growth, as the cell label is diluted during cell division. In this study we have developed cell lines stably expressing the far-red fluorescence protein E2-Crimson, thus enabling continuous detection and quantification of tumor growth. In a xenograft rat model, we show that E2-Crimson expressing cells can be detected over a 5 week period using optical imaging. Fluorescence intensities correlated with tumor volume and weight and allowed for a reliable and robust quantification of the entire tumor compartment. Using a novel injection regime, the seeding of MDA-MB-231 breast cancer cells in the lungs in a rat model was established and verified.

  15. A comparison of current prediction imaging programs

    Science.gov (United States)

    Smith, J. Dempsey; Thomas, Paul M.; Proffit, William R.

    2013-01-01

    To investigate perceived differences in the ability of current software to simulate the actual outcome of orthognathic surgery, we chose 10 difficult test cases with vertical discrepancies and “retreated” them using the actual surgical changes. Five programs—Dentofacial Planner Plus, Dolphin Imaging, Orthoplan, Quick Ceph Image, and Vistadent—were evaluated, by using both the default result and a refined result created with each program’s enhancement tools. Three panels (orthodontists, oral-maxillofacial surgeons, and laypersons) judged the default images and the retouched simulations by ranking the simulations in side-by-side comparisons and by rating each simulation relative to the actual outcome on a 6-point scale. For the default and retouched images, Dentofacial Planner Plus was judged the best default simulation 79% and 59% of the time, respectively, and its default images received the best (lowest) mean score (2.46) on the 6-point scale. It also scored best (2.26) when the retouched images were compared, but the scores for Dolphin Imaging (2.83) and Quick Ceph (3.03) improved. Retouching had little impact on the scores for the other programs. Although the results show differences in simulation ability, selecting a software package depends on many factors. Performance and ease of use, cost, compatibility, and other features such as image and practice management tools are all important considerations. Users concerned with operating system compatibility and practice management integration might want to consider Dolphin Imaging and Quick Ceph, the programs comprising the second tier. PMID:15127020

  16. Transmission (forward) mode, transcranial, noninvasive optoacoustic measurements for brain monitoring, imaging, and sensing

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Richardson, C. Joan; Fonseca, Rafael A.; Robertson, Claudia S.; Asokan, C. Vasantha; Agbor, Adaeze; Esenaliev, Rinat O.

    2016-03-01

    We proposed to use transmission (forward) mode for cerebral, noninvasive, transcranial optoacoustic monitoring, imaging, and sensing in humans. In the transmission mode, the irradiation of the tissue of interest and detection of optoacoustic signals are performed from opposite hemispheres, while in the reflection (backward) mode the irradiation of the tissue of interest and detection of optoacoustic signals are performed from the same hemisphere. Recently, we developed new, transmission-mode optoacoustic probes for patients with traumatic brain injury (TBI) and for neonatal patients. The transmission mode probes have two major parts: a fiber-optic delivery system and an acoustic transducer (sensor). To obtain optoacoustic signals in the transmission mode, in this study we placed the sensor on the forehead, while light was delivered to the opposite side of the head. Using a medical grade, multi-wavelength, OPObased optoacoustic system tunable in the near infrared spectral range (680-950 nm) and a novel, compact, fiber-coupled, multi-wavelength, pulsed laser diode-based system, we recorded optoacoustic signals generated in the posterior part of the head of adults with TBI and neonates. The optoacoustic signals had two distinct peaks: the first peak from the intracranial space and the second peak from the scalp. The first peak generated by cerebral blood was used to measure cerebral blood oxygenation. Moreover, the transmission mode measurements provided detection of intracranial hematomas in the TBI patients. The obtained results suggest that the transmission mode can be used for optoacoustic brain imaging, tomography, and mapping in humans.

  17. The temporomandibular joint in video motion--noninvasive image techniques to present the functional anatomy.

    Science.gov (United States)

    Kordass, B

    1999-01-01

    The presentation of the functional anatomy of the temporomandibular joint (TMJ) is involved with difficulties if dynamic aspects are to be of prime interest, and it should be demonstrated with the highest resolution. Usually noninvasive techniques like MRI and sonography are available for presenting functionality of the temporomandibular joint in video motion. Such images reflect the functional anatomy much better than single pictures of figures could do. In combination with computer aided records of the condyle movements the video motion of MR and sonographical images represent tools for better understanding the relationships between functional or dysfunctional patterns and the morphological or dysmorphological shape and structure of the temporomandibular joint. The possibilities of such tools will be explained and discussed in detail relating, in addition, to loading effects caused by transmitted occlusal pressure onto the joint compartments. If pressure occurs the condyle slides mainly more or less retrocranially whereas the articular disc takes up a more displaced position and a deformed shape. In a few extreme cases the disc prolapses out of the joint space. These video pictures offer new aspects for the diagnosis of the disc-condyle stability and can also be used for explicit educational programs on the complex dysfunction-dysmorphology-relationship of temporomandibular diseases.

  18. Noninvasive Prenatal Genetic Testing: Current and Emerging Ethical, Legal, and Social Issues.

    Science.gov (United States)

    Minear, Mollie A; Alessi, Stephanie; Allyse, Megan; Michie, Marsha; Chandrasekharan, Subhashini

    2015-01-01

    Noninvasive prenatal genetic testing (NIPT) for chromosomal aneuploidy involving the analysis of cell-free fetal DNA became commercially available in 2011. The low false-positive rate of NIPT, which reduces unnecessary prenatal invasive diagnostic procedures, has led to broad clinician and patient adoption. We discuss the ethical, legal, and social issues raised by rapid and global dissemination of NIPT. The number of women using NIPT is anticipated to expand, and the number of conditions being tested for will continue to increase as well, raising concerns about the routinization of testing and negative impacts on informed decision making. Ensuring that accurate and balanced information is available to all pregnant women and that access to NIPT is equitable will require policy guidance from regulators, professional societies, and payers. Empirical evidence about stakeholders' perspectives and experiences will continue to be essential in guiding policy development so that advances in NIPT can be used effectively and appropriately to improve prenatal care.

  19. Non-Invasive Glucose Monitoring Techniques: A review and current trends

    CERN Document Server

    Poddar, Raju; Shukla, Pratyoosh; Sen, Pratima

    2008-01-01

    Diabetes mellitus is a complex group of syndromes that have in common a disturbance in the body's use of glucose, resulting in an elevated blood sugar. Once detected, sugar diabetes can be controlled by an appropriate regimen that should include diet therapy, a weight reduction program for those persons who are overweight, a program of exercise and insulin injections or oral drugs to lower blood glucose. Blood glucose monitoring by the patient and the physician is an important aspect in the control of the devastating complications (heart disease, blindness, kidney failure or amputations) due to the disease. Intensive therapy and frequent glucose testing has numerous benefits. With ever improving advances in diagnostic technology, the race for the next generation of bloodless, painless, accurate glucose instruments has begun. In this paper, we reviewed various methods, techniques and approaches successfully demonstrated for measuring or monitoring blood glucose. Invasive, minimally invasive and noninvasive tec...

  20. NON-INVASIVE IMAGING OF CORONARY ARTERY WITH 16-SLICE SPIRAL COMPUTED TOMOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    Zhu-hua Zhang; Wen-bin Mou; Li-Ren Zhang; Wen-ling Zhu; Chao Ni; Hua Ren; Hong-quan Yu; Qi Miao; Qi Fang; Zheng-yu Jin; Dong-jing Li; Song-bai Lin; Shu-yang Zhang; Ling-yan Kong; Yun Wang; Lin-hui Wang; Wen-min Zhao

    2004-01-01

    Objective To evaluate the value of 16-slice spiral CT in the demonstration of coronary artery and in the diagnose of coronary artery stenosis.Methods Plain and enhanced CT scans were performed with a 16-slice CT scanner (Sensation 16, Siemens, Germany)in 230 patients with suspected coronary heart disease (CHD). Parameters of the plain scan were: 120 kV, 133 mA, slice collimation 16 mm×1.5 mm, rotation time 0.42 seconds, increment 1.5 mm, and slice width 3 mm. Parameters of the enhanced scan were: 120 kV, 500 mA, slice collimation 16 mm×0.75 mm, rotation time 0.42 seconds, increment 0.5 mm, and slice width 1 mm. Enhanced CT scan was performed with a rapid intravenous injection of 100 mL iothalamate meglumine (Ultravist)(370 mgI/mL) or Omnipaque (350mgI/mL) and 30 mL 0.9% NaC1 chaser bolus at a flow rate of 3.5 mL/s. Calcium scoring with plain scan images and two and three dimensional reconstruction with enhanced scan images were made in all cases,among which 30 cases underwent conventional coronary angiography. Demonstration of coronary arteries and their stenosis were evaluated and the factors that might influence the image quality were analyzed.Results Coronary calcium scores were calculated and coronary artery was demonstrated in our study. In the evaluation of image quality with volume rendering technique (VRT) images, 78.3% of the images were of the first class, 12.2% the second class, and 9.6% the third class. Multi-planar reconstruction (MPR) and maximal intensity projection (MIP) were better than VRT in the demonstration of small branches. The image quality was related to the heart rate, with or without arrhythmia,and breath-hold ability of patients. Comparative study of the stenosis of coronary arteries in 30 cases showed that the sensitivity and specificity of 16-slice coronary CT angiography (CTA) to diagnose significant stenosis were 95.8% and 94.8% respectively.Conclusion As a non-invasive and quick method, 16-slice coronary CTA is sensitive and

  1. Noninvasive tumor oxygen imaging by photoacoustic lifetime imaging integrated with photodynamic therapy

    Science.gov (United States)

    Shao, Qi; Biel, Merrill A.; Ashkenazi, Shai

    2014-03-01

    Oxygen plays a major role in cancer biology and tumor progression. In PDT, the reduction in efficacy is directly related to lack of oxygen because its molecular mechanism relies on oxygen as an energy mediator. Measuring tumor oxygenation can provide physicians with better diagnosis and optimization of treatment plans. However, clinical tools for directly assessing tissue oxygenation are limited. The gold standard is oxygen needle electrode, which is invasive and measures oxygen level at a single location. We present our work on developing a combined treatment-imaging modality that integrates PDT and photoacoustic oxygen imaging. We propose a system designed for clinical treatments of cancer of the oral cavity. Tissue oxygen imaging is performed by applying Photoacoustic Lifetime Imaging (PALI). This technology relies on photoacoustic probing of oxygen-dependent excitation lifetime of Methylene Blue. The dye is excited by the same wavelength of illumination source for PDT. Once excited, the population of photosensitizer molecules at triplet state has a lifetime depending on the oxygen level. The transition from excited triplet state to ground state can be probe by another laser, which generate photoacoustic signal that is used to map the lifetime. The lifetime map is then converted to pO2 distribution. We expect that PDT efficacy can be improved by applying PALI imaging feedback in real-time to determine, and individually optimize, O2-enriched gas breathing parameters and PDT light-dose during treatment. Successful implementation of PALI in PDT can also drive its application in guiding other cancer treatments that are affected by hypoxia.

  2. Noninvasive stratification of postinfarction rats based on the degree of cardiac dysfunction using magnetic resonance imaging and echocardiography.

    Science.gov (United States)

    Aronsen, Jan Magnus; Espe, Emil Knut Stenersen; Skårdal, Kristine; Hasic, Almira; Zhang, Lili; Sjaastad, Ivar

    2017-05-01

    The myocardial infarction (MI) rat model plays a crucial role in modern cardiovascular research, but the inherent heterogeneity of this model represents a challenge. We sought to identify subgroups among the post-MI rats and establish simple noninvasive stratification protocols for such subgroups. Six weeks after induction of MI, 49 rats underwent noninvasive examinations using magnetic resonance imaging (MRI) and echocardiography. Twelve sham-operated rats served as controls. Increased end-diastolic left ventricular (LV) pressure and lung weight served as indicators for congestive heart failure (CHF). A clustering algorithm using 13 noninvasive and invasive parameters was used to identify distinct groups among the animals. The cluster analysis revealed four distinct post-MI phenotypes; two without congestion but with different degree of LV dilatation, and two with different degree of congestion and right ventricular (RV) affection. Among the MRI parameters, RV mass emerged as robust noninvasive marker of CHF with 100% specificity/sensitivity. Moreover, LV infarct size and RV ejection fraction further predicted subgroup among the non-CHF and CHF rats with excellent specificity/sensitivity. Of the echocardiography parameters, left atrial diameter predicted CHF. Moreover, LV end-diastolic diameter predicted the subgroups among the non-CHF rats. We propose two simple noninvasive schemes to stratify post-MI rats, based on the degree of heart failure; one for MRI and one for echocardiography.NEW & NOTEWORTHY In vivo phenotyping of rats is essential for robust and reliable data. Here, we present two simple noninvasive schemes for the stratification of postinfarction rats based on the degree of heart failure: one using magnetic resonance imaging and one based on echocardiography. Copyright © 2017 the American Physiological Society.

  3. Evaluating non-invasive medical imaging for diagnosis of carotid artery stenosis with ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    鲁晓燕; 张挽时; 桂秋萍; 喻敏; 郭英

    2003-01-01

    Objectives To assess the value of non-invasive medical imaging for diagnosis of carotid artery stenosis and to study the relationship between carotid stenosis and brain infarction. Methods Thirty-one patients with a total of 62 carotid arteries were studied using Doppler ultrasound (DUS) and magnetic resonance angiography (MRA). Eleven of the 31 patients were studied using CT angiography (CTA). CT and MRI of the brain were also done in all patients. The imaging results in 5 patients were compared with those of digital subtraction angiography (DSA). Eight patients with severe stenosis received carotid endarterectomy. The comparisons between the imaging results and pathological data were conducted in 2 patients. Results Of the 62 carotid arteries, mild stenosis was seen in 11, moderate in 14, severe in 21, obstructed in 4 and normal in 12. In 25 patients with severe stenosis or occlusion of carotid arteries, there were a total of 35 focal or multifocal infarcts on the ipsilateral cerebral hemisphere, and 15 infarcts on the contrary side. Compared with the results of the operations, DUS correctly diagnosed 6 stenoses, while MRA identified 7 correctly and CTA 8. Agreement on location of stenosis as performed by endarterectomy, DUS, MRA and CTA occurred in all patients. Histologically, areas of calcification and fibrousness were related to high densities on CTA, strong echoes on DUS, and low signal intensities on MRA. Relatively large amounts of necrotic material and foam cells filled with lipolytic materials on the intimal surface of arteries were observed during pathologically, corresponding to low and iso-densities on CTA, low echoes on DUS, and inhomogeneous signal intensities on MRA. Conclusions A strong link exists between carotid stenosis and brain infarction. The combined use of DUS, MRA and CTA can improve diagnostic accuracy for the assessment of carotid artery stenosis, as well as assist in ascertaining the nature of the plaque.

  4. [Current status of non-invasive ventilation in German ICU's -- a postal survey].

    Science.gov (United States)

    Kumle, B; Haisch, G; Suttner, S W; Piper, S N; Maleck, W; Boldt, J

    2003-01-01

    The status of non-invasive ventilation (NIV) in intensive care units (ICU) in Germany was analysed by a national survey. Questionnaires consisting of multiple-choice and short-answer questions were sent to ICUs of university hospitals, hospitals with >1000 beds, with 500 - 1000 beds, and hospitals with pneumonia (64 %), pulmonary oedema (50 %), bronchial asthma (35 %) and ALI/ARDS (22 %). The use of NIV was considered when clinical signs of ventilation (93 %) and oxygenation [arterial blood gas analysis (92 %) and oxygen saturation (66 %)] were inadequate. Complications observed during NIV were panic reaction (83 %), ulceration of nose (38 %) and aspiration (14 %). The reasons to reject NIV were (total 13 %): lack of ventilators (64 %), expenditure of personnel (57 %) and risk of the procedure (11 %). 38 % of the ventilators used were older than 5 years. 56 % of the ICUs were content with the equipment for NIV. 76 % of the ICUs were interested to buy new equipment of NIV. 99 % of the survey have declined NIV as an alternative method of ventilation. In summary we found NIV as an accepted additional method of ventilatory support in respiratory failure in German ICUs. We found no significant increase in frequency of NIV in the last three years.

  5. Current and Future Lymphatic Imaging Modalities for Tumor Staging

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2014-01-01

    Full Text Available Tumor progression is supported by the lymphatic system which should be scanned efficiently for tumor staging as well as the enhanced therapeutic outcomes. Poor resolution and low sensitivity is a limitation of traditional lymphatic imaging modalities; thus new noninvasive approaches like nanocarriers, magnetic resonance imaging, positron-emission tomography, and quantum dots are advantageous. Some newer modalities, which are under development, and their potential uses will also be discussed in this review.

  6. Imaging iron in skin and liver: Non-invasive tools for hemochromatosis therapy

    Science.gov (United States)

    Pinheiro, T.; Fleming, R.; Gonçalves, A.; Neres, M.; Alves, L. C.; Silva, J. N.; Filipe, P.; Silva, R.

    2009-06-01

    Hemochromatosis is a hereditary disease that causes an inappropriate intestinal absorption of Fe resulting in its accumulation in multiple organs, such as liver, heart and skin. Fe metabolism indicators in the circulation do not provide reliable indication of organ overload as they can be influenced by other clinical conditions. Assessing metabolism organs such as liver requires invasive procedures which is not adequate to patient's serial observations. Our aim was establishing cross sectional and longitudinal information on the amount of Fe that deposited in skin and liver during a life period, how iron is cleared out by therapy intervention and study the relationship of these changes between the two organs using non-invasive methods. Results on skin Fe deposition were evaluated by nuclear microscopy techniques and liver Fe concentrations determined by quantitative magnetic resonance imaging. Skin and liver Fe concentrations were correlated. Though Fe deposits in the two organs were differently associated with blood Fe metabolism conventional markers. Fe serial variations in skin and liver highlighted the value of assessing Fe organ deposits for estimating hemochromatosis evolution and therapy efficacy.

  7. Mouse Reporter Strain for Noninvasive Bioluminescent Imaging of Cells that have Undergone Cre-Mediated Recombination

    Directory of Open Access Journals (Sweden)

    Michal Safran

    2003-10-01

    Full Text Available Conditional alleles containing LoxP recombination sites, in conjunction with Cre recombinase delivered by a variety of means, allows for spatial and temporal control of gene expression in mouse models. Here we describe a mouse strain in which a luciferase (Luc cDNA, preceded by a LoxP-stop-LoxP (L-S-L cassette, was introduced into the ubiquitously expressed ROSA26 locus. Mouse embryo fibroblasts derived from this strain expressed luciferase after Cre-mediated recombination in vitro. ROSA26 L-S-L-Luc/+ mice expressed luciferase in a diffuse or liver-restricted pattern, as determined by noninvasive, bioluminescent imaging, when crossed to transgenic mice in which Cre was under the control of a zygotically expressed (EIIA-Cre, or a liver-restricted (albumin-Cre, promoter, respectively. Organ-specific luciferase expression was also seen after intraparenchymal administration of an adenovirus encoding Cre. The ROSA26 L-S-L-Luc/+ strain should be useful for characterizing Cre mouse strains and for following the fate of cells that have undergone Cre-mediated recombination in vivo.

  8. Noninvasive In Toto Imaging of the Thymus Reveals Heterogeneous Migratory Behavior of Developing T Cells.

    Science.gov (United States)

    Bajoghli, Baubak; Kuri, Paola; Inoue, Daigo; Aghaallaei, Narges; Hanelt, Marleen; Thumberger, Thomas; Rauzi, Matteo; Wittbrodt, Joachim; Leptin, Maria

    2015-09-01

    The migration of developing T cells (thymocytes) between distinct thymic microenvironments is crucial for their development. Ex vivo studies of thymus tissue explants suggest two distinct migratory behaviors of thymocytes in the thymus. In the cortex, thymocytes exhibit a stochastic migration, whereas medullary thymocytes show confined migratory behavior. Thus far, it has been difficult to follow all thymocytes in an entire thymus and relate their differentiation steps to their migratory dynamics. To understand the spatial organization of the migratory behavior and development of thymocytes in a fully functional thymus, we developed transgenic reporter lines for the chemokine receptors ccr9a and ccr9b, as well as for rag2, and used them for noninvasive live imaging of the entire thymus in medaka (Oryzias latipes). We found that the expression of these two chemokine receptors in the medaka juvenile thymus defined two spatially distinct subpopulations of thymocytes. Landmark events of T cell development including proliferation, somatic recombination, and thymic selection can be mapped to subregions of the thymus. The migratory behavior of thymocytes within each of the subpopulations is equally heterogeneous, and specific migratory behaviors are not associated with particular domains in the thymus. During the period when thymocytes express rag2 their migratory behavior was more homogeneous. Therefore, the migratory behavior of thymocytes is partly correlated with their developmental stage rather than being defined by their spatial localization.

  9. Imaging iron in skin and liver: Non-invasive tools for hemochromatosis therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, T. [Instituto Tecnologico e Nuclear and Centro de Fisica Nuclear/UL, E.N. 10, 2685-953 Sacavem (Portugal)], E-mail: murmur@itn.pt; Fleming, R. [Servico Imunohemoterapia, Hospital de Santa Maria, Lisboa (Portugal); Goncalves, A. [Servico de Imagiologia Geral, Hospital de Santa Maria, Lisboa (Portugal); Neres, M.; Alves, L.C. [Instituto Tecnologico e Nuclear and Centro de Fisica Nuclear/UL, E.N. 10, 2685-953 Sacavem (Portugal); Silva, J.N.; Filipe, P.; Silva, R. [Clinica Universitaria de Dermatologia, Hospital de Santa Maria and Faculdade de Medicina/UL, Lisboa (Portugal)

    2009-06-15

    Hemochromatosis is a hereditary disease that causes an inappropriate intestinal absorption of Fe resulting in its accumulation in multiple organs, such as liver, heart and skin. Fe metabolism indicators in the circulation do not provide reliable indication of organ overload as they can be influenced by other clinical conditions. Assessing metabolism organs such as liver requires invasive procedures which is not adequate to patient's serial observations. Our aim was establishing cross sectional and longitudinal information on the amount of Fe that deposited in skin and liver during a life period, how iron is cleared out by therapy intervention and study the relationship of these changes between the two organs using non-invasive methods. Results on skin Fe deposition were evaluated by nuclear microscopy techniques and liver Fe concentrations determined by quantitative magnetic resonance imaging. Skin and liver Fe concentrations were correlated. Though Fe deposits in the two organs were differently associated with blood Fe metabolism conventional markers. Fe serial variations in skin and liver highlighted the value of assessing Fe organ deposits for estimating hemochromatosis evolution and therapy efficacy.

  10. Combined Neutron and X-ray Imaging for Non-invasive Investigations of Cultural Heritage Objects

    Science.gov (United States)

    Mannes, D.; Schmid, F.; Frey, J.; Schmidt-Ott, K.; Lehmann, E.

    The combined utilization of neutron and X-ray imaging for non-invasive investigations of cultural heritage objects is demonstrated on the example of a short sword found a few years ago in lake Zug, Switzerland. After conservation treatments carried out at the Swiss National Museum the sword was examined at the Paul Scherrer Institut (PSI), Villigen (CH), by means of neutron and X-ray computer tomography (CT). The two types of radiation show different interaction behavior with matter, which makes the two methods complementary. While X-rays show a strong correlation of the attenuation with the atomic number, neutrons demonstrate a high sensitivity for some light elements, such as Hydrogen and thus organic material, while some heavy elements (such as Lead) show high penetrability. The examined object is a composite of metal and organic material, which makes it an ideal example to show the complementarity of the two methods as it features materials, which are rather transparent for one type of radiation, while yielding at the same time high contrast for the other. Only the combination of the two methods made an exhaustive examination of the object possible and allowed to rebuild an accurate replica of the sword.

  11. Histone deacetylase inhibition increases levels of choline kinase α and phosphocholine facilitating noninvasive imaging in human cancers.

    Science.gov (United States)

    Beloueche-Babari, Mounia; Arunan, Vaitha; Troy, Helen; te Poele, Robert H; te Fong, Anne-Christine Wong; Jackson, L Elizabeth; Payne, Geoffrey S; Griffiths, John R; Judson, Ian R; Workman, Paul; Leach, Martin O; Chung, Yuen-Li

    2012-02-15

    Histone deacetylase (HDAC) inhibitors are currently approved for cutaneous T-cell lymphoma and are in mid-late stage trials for other cancers. The HDAC inhibitors LAQ824 and SAHA increase phosphocholine (PC) levels in human colon cancer cells and tumor xenografts as observed by magnetic resonance spectroscopy (MRS). In this study, we show that belinostat, an HDAC inhibitor with an alternative chemical scaffold, also caused a rise in cellular PC content that was detectable by (1)H and (31)P MRS in prostate and colon carcinoma cells. In addition, (1)H MRS showed an increase in branched chain amino acid and alanine concentrations. (13)C-choline labeling indicated that the rise in PC resulted from increased de novo synthesis and correlated with an induction of choline kinase α expression. Furthermore, metabolic labeling experiments with (13)C-glucose showed that differential glucose routing favored alanine formation at the expense of lactate production. Additional analysis revealed increases in the choline/water and phosphomonoester (including PC)/total phosphate ratios in vivo. Together, our findings provide mechanistic insights into the impact of HDAC inhibition on cancer cell metabolism and highlight PC as a candidate noninvasive imaging biomarker for monitoring the action of HDAC inhibitors.

  12. Development of a translation stage for in situ noninvasive analysis and high-resolution imaging

    Science.gov (United States)

    Strivay, David; Clar, Mathieu; Rakkaa, Said; Hocquet, Francois-Philippe; Defeyt, Catherine

    2016-11-01

    Noninvasive imaging techniques and analytical instrumentation for cultural heritage object studies have undergone a tremendous development over the last years. Many new miniature and/or handheld systems have been developed and optimized. Nonetheless, these instruments are usually used with a tripod or a manual position system. This is very time consuming when performing point analysis or 2D scanning of a surface. The Centre Européen d'Archéométrie has built a translation system made of pluggable rails of 1 m long with a maximum length and height of 3 m. Three motors embedded in the system allow the platform to be moved along these axis, toward and backward from the sample. The rails hold a displacement system, providing a continuous movement. Any position can be reached with a reproducibility of 0.1 mm. The displacements are controlled by an Ethernet connection through a laptop computer running a multiplatform custom-made software written in JAVA. This software allows a complete control over the positioning using a simple, unique, and concise interface. Automatic scanning can be performed over a large surface of 3 m on 3 m. The Ethernet wires provide also the power for the different motors and, if necessary, the detection head. The platform has been originally designed for a XRF detection head (with its full power alimentation) but now can accommodate many different systems like IR reflectography, digital camera, hyperspectral camera, and Raman probes. The positioning system can be modified to combine the acquisition software of the imaging or analytical techniques and the positioning software.

  13. Noninvasive fluorescence resonance energy transfer imaging of in vivo premature drug release from polymeric nanoparticles.

    Science.gov (United States)

    Zou, Peng; Chen, Hongwei; Paholak, Hayley J; Sun, Duxin

    2013-11-01

    Understanding in vivo drug release kinetics is critical for the development of nanoparticle-based delivery systems. In this study, we developed a fluorescence resonance energy transfer (FRET) imaging approach to noninvasively monitor in vitro and in vivo cargo release from polymeric nanoparticles. The FRET donor dye (DiO or DiD) and acceptor dye (DiI or DiR) were individually encapsulated into poly(ethylene oxide)-b-polystyrene (PEO-PS) nanoparticles. When DiO (donor) nanoparticles and DiI (acceptor) nanoparticles were coincubated with cancer cells for 2 h, increased FRET signals were observed from cell membranes, suggesting rapid release of DiO and DiI to cell membranes. Similarly, increased FRET ratios were detected in nude mice after intravenous coadministration of DiD (donor) nanoparticles and DiR (acceptor) nanoparticles. In contrast, another group of nude mice i.v. administrated with DiD/DiR coloaded nanoparticles showed decreased FRET ratios. Based on the difference in FRET ratios between the two groups, in vivo DiD/DiR release half-life from PEO-PS nanoparticles was determined to be 9.2 min. In addition, it was observed that the presence of cell membranes facilitated burst release of lipophilic cargos while incorporation of oleic acid-coated iron oxide into PEO-PS nanoparticles slowed the release of DiD/DiR to cell membranes. The developed in vitro and in vivo FRET imaging techniques can be used to screening stable nanoformulations for lipophilic drug delivery.

  14. Dark-field imaging as a non-invasive method for characterization of whispering gallery modes in microdisk cavities

    CERN Document Server

    Baranov, D A; Shishkin, I I; Samusev, A K; Belov, P A; Bogdanov, A A

    2016-01-01

    Whispering gallery mode microdisk cavities fabricated by direct laser writing are studied using dark-field imaging and spectroscopy in the visible spectral range. {Dark-field imaging allows us to directly visualize the spatial intensity distribution of whispering gallery modes. We extract their azimuthal and radial mode indices from dark-field images, and find the axial mode number from the dispersion relation. The scattering spectrum obtained in the confocal arrangement provides information on the density of optical states in the resonator. The proposed technique is a simple non-invasive way to characterize the optical properties of microdisk cavities.

  15. Non-invasive cardiac pacing with image-guided focused ultrasound

    Science.gov (United States)

    Marquet, Fabrice; Bour, Pierre; Vaillant, Fanny; Amraoui, Sana; Dubois, Rémi; Ritter, Philippe; Haïssaguerre, Michel; Hocini, Mélèze; Bernus, Olivier; Quesson, Bruno

    2016-11-01

    Currently, no non-invasive cardiac pacing device acceptable for prolonged use in conscious patients exists. High Intensity Focused Ultrasound (HIFU) can be used to perform remote pacing using reversibility of electromechanical coupling of cardiomyocytes. Here we described an extracorporeal cardiac stimulation device and study its efficacy and safety. We conducted experiments ex vivo and in vivo in a large animal model (pig) to evaluate clinical potential of such a technique. The stimulation threshold was determined in 10 different ex vivo hearts and different clinically relevant electrical effects such as consecutive stimulations of different heart chambers with a single ultrasonic probe, continuous pacing or the inducibility of ventricular tachycardia were shown. Using ultrasonic contrast agent, consistent cardiac stimulation was achievable in vivo for up to 1 hour sessions in 4 different animals. No damage was observed in inversion-recovery MR sequences performed in vivo in the 4 animals. Histological analysis revealed no differences between stimulated and control regions, for all ex vivo and in vivo cases.

  16. Reproducibility of non-invasive assessment of skin endothelial function using laser Doppler flowmetry and laser speckle contrast imaging.

    Directory of Open Access Journals (Sweden)

    Cyril Puissant

    Full Text Available BACKGROUND: Endothelial dysfunction precedes atherosclerosis. Vasodilation induced by acetylcholine (ACh is a specific test of endothelial function. Reproducibility of laser techniques such as laser-Doppler-flowmetry (LDF and Laser-speckle-contrast-imaging (LSCI to detect ACh vasodilation is debated and results expressions lack standardization. We aimed to study at a 7-day interval (i the inter-subject reproducibility, (ii the intra-subjects reproducibility, and (iii the effect of the results expressions over variability. METHODS AND RESULTS: Using LDF and LSCI simultaneously, we performed two different ACh-iontophoresis protocols. The maximal ACh vasodilation (peak-ACh was expressed as absolute or normalized flow or conductance values. Inter-subject reproducibility was expressed as coefficient of variation (inter-CV,%. Intra-subject reproducibility was expressed as within subject coefficients of variation (intra-CV,%, and intra-class correlation coefficients (ICC. Fifteen healthy subjects were included. The inter-subject reproducibility of peak-ACh depended upon the expression of the results and ranged from 55% to 162% for LDF and from 17% to 83% for LSCI. The intra-subject reproducibility (intra-CV/ICC of peak-ACh was reduced when assessed with LSCI compared to LDF no matter how the results were expressed and whatever the protocol used. The highest intra-subject reproducibility was found using LSCI. It was 18.7%/0.87 for a single current stimulation (expressed as cutaneous vascular conductance and 11.4%/0.61 for multiple current stimulations (expressed as absolute value. CONCLUSION: ACh-iontophoresis coupled with LSCI is a promising test to assess endothelial function because it is reproducible, safe, and non-invasive. N°: NCT01664572.

  17. Near-infrared fluorescence imaging for noninvasive trafficking of scaffold degradation.

    Science.gov (United States)

    Kim, Soon Hee; Lee, Jeong Heon; Hyun, Hoon; Ashitate, Yoshitomo; Park, Gwangli; Robichaud, Kyle; Lunsford, Elaine; Lee, Sang Jin; Khang, Gilson; Choi, Hak Soo

    2013-01-01

    Biodegradable scaffolds could revolutionize tissue engineering and regenerative medicine; however, in vivo matrix degradation and tissue ingrowth processes are not fully understood. Currently a large number of samples and animals are required to track biodegradation of implanted scaffolds, and such nonconsecutive single-time-point information from various batches result in inaccurate conclusions. To overcome this limitation, we developed functional biodegradable scaffolds by employing invisible near-infrared fluorescence and followed their degradation behaviors in vitro and in vivo. Using optical fluorescence imaging, the degradation could be quantified in real-time, while tissue ingrowth was tracked by measuring vascularization using magnetic resonance imaging in the same animal over a month. Moreover, we optimized the in vitro process of enzyme-based biodegradation to predict implanted scaffold behaviors in vivo, which was closely related to the site of inoculation. This combined multimodal imaging will benefit tissue engineers by saving time, reducing animal numbers, and offering more accurate conclusions.

  18. Noninvasive Phosphorus Magnetic Resonance Spectroscopic Imaging Predicts Outcome to First-line Chemotherapy in Newly Diagnosed Patients with Diffuse Large B-Cell Lymphoma

    NARCIS (Netherlands)

    Arias-Mendoza, F.; Payne, G.S.; Zakian, K.; Stubbs, M.; O'Connor, O.A.; Mojahed, H.; Smith, M.R.; Schwarz, A.J.; Shukla-Dave, A.; Howe, F.; Poptani, H.; Lee, S.-C.; Pettengel, R.; Schuster, S.J.; Cunningham, D.; Heerschap, A.; Glickson, J.D.; Griffiths, J.R.; Koutcher, J.A.; Leach, M.O.; Brown, T.R.

    2013-01-01

    Based on their association with malignant proliferation, using noninvasive phosphorus MR spectroscopic imaging ((31)P MRSI), we measured the tumor content of the phospholipid-related phosphomonoesters (PME), phosphoethanolamine and phospholcholine, and its correlation with treatment outcome in newly

  19. Noninvasive monitoring of placenta-specific transgene expression by bioluminescence imaging.

    Directory of Open Access Journals (Sweden)

    Xiujun Fan

    Full Text Available BACKGROUND: Placental dysfunction underlies numerous complications of pregnancy. A major obstacle to understanding the roles of potential mediators of placental pathology has been the absence of suitable methods for tissue-specific gene manipulation and sensitive assays for studying gene functions in the placentas of intact animals. We describe a sensitive and noninvasive method of repetitively tracking placenta-specific gene expression throughout pregnancy using lentivirus-mediated transduction of optical reporter genes in mouse blastocysts. METHODOLOGY/PRINCIPAL FINDINGS: Zona-free blastocysts were incubated with lentivirus expressing firefly luciferase (Fluc and Tomato fluorescent fusion protein for trophectoderm-specific infection and transplanted into day 3 pseudopregnant recipients (GD3. Animals were examined for Fluc expression by live bioluminescence imaging (BLI at different points during pregnancy, and the placentas were examined for tomato expression in different cell types on GD18. In another set of experiments, blastocysts with maximum photon fluxes in the range of 2.0E+4 to 6.0E+4 p/s/cm(2/sr were transferred. Fluc expression was detectable in all surrogate dams by day 5 of pregnancy by live imaging, and the signal increased dramatically thereafter each day until GD12, reaching a peak at GD16 and maintaining that level through GD18. All of the placentas, but none of the fetuses, analyzed on GD18 by BLI showed different degrees of Fluc expression. However, only placentas of dams transferred with selected blastocysts showed uniform photon distribution with no significant variability of photon intensity among placentas of the same litter. Tomato expression in the placentas was limited to only trophoblast cell lineages. CONCLUSIONS/SIGNIFICANCE: These results, for the first time, demonstrate the feasibility of selecting lentivirally-transduced blastocysts for uniform gene expression in all placentas of the same litter and early

  20. The current status of continuous noninvasive measurement of total, carboxy, and methemoglobin concentration.

    Science.gov (United States)

    Shamir, Micha Y; Avramovich, Aharon; Smaka, Todd

    2012-05-01

    Intraoperative early detection of anemia, identifying toxic levels of carboxyhemoglobin after carbon monoxide exposure and titrating drug dosage to prevent toxic levels of methemoglobin are important goals. The pulse oximeter works by illuminating light into the tissue and sensing the amount of light absorbed. The same methodology is used by laboratory hemoglobinometers to measure hemoglobin concentration. Because both devices work in the same way, efforts were made to modify the pulse oximeter to also measure hemoglobin concentration. Currently there are 2 commercial pulse oximeters (Masimo Rainbow SET and OrSense NBM-200MP) that measure total hemoglobin concentration and one (Masimo) that also measures methemoglobin and carboxyhemoglobin. In this review, we describe the peer-reviewed literature addressing the accuracy of these monitors.

  1. Noninvasive imaging of receptor function: signal transduction pathways and physiological readouts.

    Science.gov (United States)

    Rudin, Markus

    2008-09-01

    Intracellular signaling describes the process of information propagation from the cell surface to the location within the cell where a biological response is executed. Signaling pathways involve a complex network of interacting molecular species. It is obvious that information on the activation of individual pathways is highly relevant in biomedical research, both from a diagnostic point of view and for evaluating therapeutic interventions. Modern molecular imaging approaches are capable of providing such information in a temporo-spatially resolved manner. Two strategies can be pursued: imaging individual pathway molecules or targeting protein-protein interactions, which are key elements of the signaling networks. Assays such as fluorescence resonance energy transfer, two-hybrid, protein fragment complementation or protein splicing have been adapted to allow studies in live mice. The major issues in imaging signal transduction are sensitivity, as critical species occur at low concentration, and the fact that the processes targeted are intracellular, that is, exogenous probes have to cross the cell membrane. Currently, the majority of these imaging methods are based on genetic engineering approaches and are therefore confined to experimental studies in animals. Exogenous probes for targeting intracellular pathway molecules are being developed and may allow translation into the clinic.

  2. [Non-invasive brain stimulation in neurology : Transcranial direct current stimulation to enhance cognitive functioning].

    Science.gov (United States)

    Antonenko, D; Flöel, A

    2016-08-01

    Transcranial direct current stimulation (tDCS) has been successfully used in neuroscientific research to modulate cognitive functions. Recent studies suggested that improvement of behavioral performance is associated with tDCS-induced modulation of neuronal activity and connectivity. Thus, tDCS may also represent a promising tool for reconstitution of cognitive functions in the context of memory decline related to Alzheimer's disease or aphasia following stroke; however, evidence from randomized sham-controlled clinical trials is still scarce. Initial results of tDCS-induced behavioral improvement in patients with Alzheimer's dementia and its precursors indicated that an intense memory training combined with tDCS may be effective. Early interventions in the stage of mild cognitive impairment could be crucial but further evidence is needed to substantiate this. In patients with aphasia following stroke tDCS was applied to the left and right hemispheres, with varying results depending on the severity of the symptoms and polarity of the stimulation. Patients with mild aphasia can benefit from tDCS of the language dominant hemisphere while in patients with severe aphasia tDCS of right hemispheric homologous brain language areas may be particularly relevant. Moreover, recent studies suggested that an intervention in the subacute phase of aphasia could be most promising. In summary, tDCS could provide the exciting possibility to reconstitute cognitive functions in patients with neurological disorders. Future studies have to elucidate whether tDCS can be used in the clinical routine to prevent further cognitive decline in neurodegenerative diseases and whether beneficial effects from experimental studies translate into long-term improvement in activities of daily life.

  3. Non-Invasive MRI and Spectroscopy of mdx Mice Reveal Temporal Changes in Dystrophic Muscle Imaging and in Energy Deficits

    Science.gov (United States)

    Heier, Christopher R.; Guerron, Alfredo D.; Korotcov, Alexandru; Lin, Stephen; Gordish-Dressman, Heather; Fricke, Stanley; Sze, Raymond W.; Hoffman, Eric P.; Wang, Paul; Nagaraju, Kanneboyina

    2014-01-01

    In Duchenne muscular dystrophy (DMD), a genetic disruption of dystrophin protein expression results in repeated muscle injury and chronic inflammation. Magnetic resonance imaging shows promise as a surrogate outcome measure in both DMD and rehabilitation medicine that is capable of predicting clinical benefit years in advance of functional outcome measures. The mdx mouse reproduces the dystrophin deficiency that causes DMD and is routinely used for preclinical drug testing. There is a need to develop sensitive, non-invasive outcome measures in the mdx model that can be readily translatable to human clinical trials. Here we report the use of magnetic resonance imaging and spectroscopy techniques for the non-invasive monitoring of muscle damage in mdx mice. Using these techniques, we studied dystrophic mdx muscle in mice from 6 to 12 weeks of age, examining both the peak disease phase and natural recovery phase of the mdx disease course. T2 and fat-suppressed imaging revealed significant levels of tissue with elevated signal intensity in mdx hindlimb muscles at all ages; spectroscopy revealed a significant deficiency of energy metabolites in 6-week-old mdx mice. As the mdx mice progressed from the peak disease stage to the recovery stage of disease, each of these phenotypes was either eliminated or reduced, and the cross-sectional area of the mdx muscle was significantly increased when compared to that of wild-type mice. Histology indicates that hyper-intense MRI foci correspond to areas of dystrophic lesions containing inflammation as well as regenerating, degenerating and hypertrophied myofibers. Statistical sample size calculations provide several robust measures with the ability to detect intervention effects using small numbers of animals. These data establish a framework for further imaging or preclinical studies, and they support the development of MRI as a sensitive, non-invasive outcome measure for muscular dystrophy. PMID:25390038

  4. In vivo imaging of enamel by reflectance confocal microscopy (RCM): non-invasive analysis of dental surface.

    Science.gov (United States)

    Contaldo, Maria; Serpico, Rosario; Lucchese, Alberta

    2014-07-01

    The aim is to establish the feasibility to image in vivo microscopic dental surface by non-invasive, real-time, en face Reflectance Confocal Microscopy (RCM). Fifteen healthy volunteers referred at the Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, Second University of Naples, Naples, Italy, were enrolled. A commercially available hand-held RCM (Vivascope(®)3000, Lucid, Rochester, NY, USA) was used to image in vivo the dental surface of the upper right and left central incisors of each volunteer. Totally, thirty vestibular surfaces of upper central incisors were imaged in vivo by RCM to preliminary image the dental surface and assess the feasibility of a more extended study on teeth. In vivo RCM was able to image the dental surface within the enamel, at a maximum depth imaging of 300 μm, with images good in quality and the capability to detect enamel structures such as enamel lamellae and enamel damages, such as unevenness and cracks. In conclusion, enamel "optical biopsy", gained by RCM imaging, revealed to be a non-invasive real-time tool valid to obtain architectural details of the dental surface with no need for extraction or processing the samples. RCM appears to be an optimum auxiliary device for investigating the architectural pattern of superficial enamel, therefore inviting further experiments aimed to define our knowledge about damages after etching treatments or bracket removal and the responsiveness to fluoride seals and the morphology of the tooth/restoration interface. Moreover, this device could also be used to detect relevant diseases like caries, or to assess surface properties to evaluate lesion activity.

  5. Evaluation of non-invasive multispectral imaging as a tool for measuring the effect of systemic therapy in Kaposi sarcoma.

    Directory of Open Access Journals (Sweden)

    Jana M Kainerstorfer

    Full Text Available Diffuse multi-spectral imaging has been evaluated as a potential non-invasive marker of tumor response. Multi-spectral images of Kaposi sarcoma skin lesions were taken over the course of treatment, and blood volume and oxygenation concentration maps were obtained through principal component analysis (PCA of the data. These images were compared with clinical and pathological responses determined by conventional means. We demonstrate that cutaneous lesions have increased blood volume concentration and that changes in this parameter are a reliable indicator of treatment efficacy, differentiating responders and non-responders. Blood volume decreased by at least 20% in all lesions that responded by clinical criteria and increased in the two lesions that did not respond clinically. Responses as assessed by multi-spectral imaging also generally correlated with overall patient clinical response assessment, were often detectable earlier in the course of therapy, and are less subject to observer variability than conventional clinical assessment. Tissue oxygenation was more variable, with lesions often showing decreased oxygenation in the center surrounded by a zone of increased oxygenation. This technique could potentially be a clinically useful supplement to existing response assessment in KS, providing an early, quantitative, and non-invasive marker of treatment effect.

  6. Assessment of small bowel Crohn disease: noninvasive peroral CT enterography compared with other imaging methods and endoscopy--feasibility study.

    Science.gov (United States)

    Wold, Peter B; Fletcher, Joel G; Johnson, C Daniel; Sandborn, William J

    2003-10-01

    A feasibility study was conducted to evaluate two biphasic computed tomographic (CT) enterography protocols, a noninvasive CT technique with water administered perorally and CT enteroclysis with methylcellulose administered through a nasojejunal tube, in 23 patients known or suspected to have Crohn disease. Results were compared with the results of fluoroscopic small bowel examination and terminal ileoscopy for the detection of active Crohn disease in the terminal ileum. Luminal distention did not differ significantly between the two CT protocols. Arterial phase imaging was noncontributory in 22 of 23 cases. The noninvasive peroral water CT enterography protocol had similar accuracy (12 of 15 cases, 80%) for enabling the detection of active Crohn disease in comparison with CT enteroclysis with nasojejunal tube (seven of eight, 88%) and fluoroscopic small bowel examination (17 of 23, 74%). No fistulas were missed with use of either CT technique. The authors conclude that noninvasive peroral portal venous phase CT enterography with use of water is an accurate and feasible technique for detecting active small bowel inflammation in patients with Crohn disease.

  7. Non-invasive brain stimulation for the treatment of brain diseases in childhood and adolescence: state of the art, current limits and future challenges

    Directory of Open Access Journals (Sweden)

    Carmelo Mario Vicario

    2013-11-01

    Full Text Available In the last decades interest in application of non-invasive brain stimulation for enhancing neural functions is growing continuously. However, the use of such techniques in pediatric populations remains rather limited and mainly confined to the treatment of severe neurological and psychiatric diseases. In this article we provide a complete review of non-invasive brain stimulation studies conducted in pediatric populations. We also provide a brief discussion about the current limitations and future directions in a field of research still very young and full of issues to be explored.

  8. Non-invasive cardiac imaging techniques and vascular tools for the assessment of cardiovascular disease in type 2 diabetes mellitus.

    Science.gov (United States)

    Djaberi, R; Beishuizen, E D; Pereira, A M; Rabelink, T J; Smit, J W; Tamsma, J T; Huisman, M V; Jukema, J W

    2008-09-01

    Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima-media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of 'at risk' patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG.

  9. Aqueous synthesis of PbS quantum dots for noninvasive near-infrared fluorescence imaging in a mouse model

    Science.gov (United States)

    Deng, Dawei; Chen, Xinyang; Zhang, Jian; Liu, Fei; Cao, Jie; Gu, Yueqing

    2010-02-01

    In this paper, we present a new facile and environmental friendly method to prepare water-soluble near-infrared (NIR)-emitting PbS quantum dots (QDs) at room temperature under ambient conditions, using dihydrolipoic acid (DHLA) as a stabilizer. The photoluminescence (PL) emissions of the prepared DHLA-capped PbS QDs are tunable between 870 and 1010 nm. A PL quantum yield (QY) of ~10% can be achieved under optimized conditions without any post-preparative treatment. Here, we further use the produced DHLA-capped PbS QDs for NIR fluorescence imaging in a mouse model. The obtained experimental results showed that the NIR fluorescence of the PbS QDs in living tissues generated from the excitation with semiconductor laser (λmax=765.9 nm) could penetrate living tissues and be detected easily by the noninvasive in vivo NIR fluorescence imaging system. In addition, the preliminary studies on the cytotoxicity and in vivo toxicity of the QDs also indicates fully that these water-soluble DHLA-capped PbS QDs are very lowly toxic, and as such they should have greater potential in biological and medical applications especially in noninvasive in vivo fluorescence imaging of mice, compared to other existing highly toxic aqueous NIR-emitting quantum dots (CdTe, HgTe, etc).

  10. Noninvasive assessment of cutaneous alterations in mice exposed to whole body gamma irradiation using optical imaging techniques.

    Science.gov (United States)

    Sharma, P; Sahu, K; Kushwaha, P K; Kumar, S; Swami, M K; Kumawat, J; Patel, H S; Kher, S; Sahani, P K; Haridas, G; Gupta, P K

    2017-07-11

    We report the results of a study carried out to investigate the potential of optical techniques such as optical coherence tomography, Mueller matrix spectroscopy, and cross-polarization imaging for noninvasive monitoring of the ionizing radiation exposure-induced alterations in cutaneous tissue of mice. Radiation dose-dependent changes were observed in tissue microvasculature and tissue optical parameters like retardance and depolarization as early as 1 h post radiation exposure. Results suggest that these optical techniques may allow early detection of radiation dose-dependent alterations which could help in screening of population exposed to radiation.

  11. Noninvasive Quantitative Imaging of Collagen Microstructure in Three-Dimensional Hydrogels Using High-Frequency Ultrasound

    OpenAIRE

    Mercado, Karla P.; Helguera, María; Hocking, Denise C.; Dalecki, Diane

    2015-01-01

    Collagen I is widely used as a natural component of biomaterials for both tissue engineering and regenerative medicine applications. The physical and biological properties of fibrillar collagens are strongly tied to variations in collagen fiber microstructure. The goal of this study was to develop the use of high-frequency quantitative ultrasound to assess collagen microstructure within three-dimensional (3D) hydrogels noninvasively and nondestructively. The integrated backscatter coefficient...

  12. Magnetic force microscopy/current contrast imaging: A new technique for internal current probing of ICs

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.N.; Cole, E.I. Jr.; Dodd, B.A.; Anderson, R.E.

    1993-09-01

    This invited paper describes recently reported work on the application of magnetic force microscopy (MFM) to image currents in IC conductors [1]. A computer model for MFM imaging of IC currents and experimental results demonstrating the ability to determine current direction and magnitude with a resolution of {approximately} 1 mA dc and {approximately} 1 {mu}A ac are presented. The physics of MFM signal generation and applications to current imaging and measurement are described.

  13. Reflectance confocal microscopy and dermoscopy for in vivo, non-invasive skin imaging of superficial basal cell carcinoma

    Science.gov (United States)

    GHITA, MIHAELA A.; CARUNTU, CONSTANTIN; ROSCA, ADRIAN E.; KALESHI, HARILLAQ; CARUNTU, ANA; MORARU, LILIANA; DOCEA, ANCA OANA; ZURAC, SABINA; BODA, DANIEL; NEAGU, MONICA; SPANDIDOS, DEMETRIOS A.; TSATSAKIS, ARISTIDIS M.

    2016-01-01

    Superficial basal cell carcinoma (sBCC) is the second most frequent histological type of basal cell carcinoma (BCC), usually requiring a skin biopsy to confirm the diagnosis. It usually appears on the upper trunk and shoulders as erythematous and squamous lesions. Although it has a slow growth and seldom metastasizes, early diagnosis and management are of crucial importance in preventing local invasion and subsequent disfigurement. Dermoscopy is nowadays an indispensable tool for the dermatologist when evaluating skin tumors. Reflectance confocal microscopy (RCM) is a novel imaging technique that allows the non-invasive, in vivo quasi-microscopic morphological and dynamic assessment of superficial skin tumors. Moreover, it offers the advantage of performing infinite repeatable determinations to monitor disease progression and non-surgical treatment for sBCC. Herein, we present three lesions of sBCC evaluated using in vivo and non-invasive imaging techniques, emphasizing the usefulness of combining RCM with dermoscopy for increasing the diagnostic accuracy of sBCC. PMID:27123056

  14. Magnetic single-walled carbon nanotubes as efficient drug delivery nanocarriers in breast cancer murine model: noninvasive monitoring using diffusion-weighted magnetic resonance imaging as sensitive imaging biomarker

    Directory of Open Access Journals (Sweden)

    Al Faraj A

    2014-12-01

    Full Text Available Achraf Al Faraj,1 Abjal Pasha Shaik,2 Asma Sultana Shaik1,3 1Department of Radiological Sciences, 2Department of Clinical Lab Sciences, College of Applied Medical Sciences, 3Prince Naif Health Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia Purpose: Targeting doxorubicin (DOX by means of single-walled carbon nanotube (SWCNT nanocarriers may help improve the clinical utility of this highly active therapeutic agent. Active targeting of SWCNTs using tumor-specific antibody and magnetic attraction by tagging the nanotubes with iron oxide nanoparticles can potentially reduce the unnecessary side effects and provide enhanced theranostics. In the current study, the in vitro and in vivo efficacy of DOX-loaded SWCNTs as theranostic nanoprobes was evaluated in a murine breast cancer model.Methods: Iron-tagged SWCNTs conjugated with Endoglin/CD105 antibody with or without DOX were synthetized and extensively characterized. Their biocompatibility was assessed in vitro in luciferase (Luc2-expressing 4T1 (4T1-Luc2 murine breast cancer cells using TiterTACS™ Colorimetric Apoptosis Detection Kit (apoptosis induction, poly (ADP-ribose polymerase (marker for DNA damage, and thiobarbituric acid-reactive substances (oxidative stress generation assays, and the efficacy of DOX-loaded SWCNTs was evaluated by measuring the radiance efficiency using bioluminescence imaging (BLI. Tumor progression and growth were monitored after 4T1-Luc2 cells inoculation using noninvasive BLI and magnetic resonance imaging (MRI before and after subsequent injection of SWCNT complexes actively and magnetically targeted to tumor sites.Results: Significant increases in apoptosis, DNA damage, and oxidative stress were induced by DOX-loaded SWCNTs. In addition, a tremendous decrease in bioluminescence was observed in a dose- and time-dependent manner. Noninvasive BLI and MRI revealed successful tumor growth and subsequent attenuation along with metastasis

  15. Current status and future perspectives of in vivo small animal imaging using radiolabeled nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Loudos, George, E-mail: gloudos@teiath.gr [Department of Medical Instruments Technology, Technological Educational Institute of Athens, AG. Spyridonos 28, Egaleo 12210 (Greece); Kagadis, George C., E-mail: gkagad@gmail.com [Department of Medical Physics, School of Medicine, University of Patras, P.O. Box 13273, GR-265 04 Rion (Greece); Psimadas, Dimitris, E-mail: dpsimad@chem.uoa.gr [Department of Medical Instruments Technology, Technological Educational Institute of Athens, AG. Spyridonos 28, Egaleo 12210 (Greece); Institute of Radioisotopes and Radiodiagnostic Products, National Center of Scientific Research ' Demokritos' , P.O. 60228, 153 10 Agia Paraskevi, Athens (Greece)

    2011-05-15

    Small animal molecular imaging is a rapidly expanding efficient tool to study biological processes non-invasively. The use of radiolabeled tracers provides non-destructive, imaging information, allowing time related phenomena to be repeatedly studied in a single animal. In the last decade there has been an enormous progress in related technologies and a number of dedicated imaging systems overcome the limitations that the size of small animal possesses. On the other hand, nanoparticles (NPs) gain increased interest, due to their unique properties, which make them perfect candidates for biological applications. Over the past 5 years the two fields seem to cross more and more often; radiolabeled NPs have been assessed in numerous pre-clinical studies that range from oncology, till HIV treatment. In this article the current status in the tools, applications and trends of radiolabeled NPs reviewed.

  16. Non-invasive parenchymal, vascular and metabolic high-frequency ultrasound and photoacoustic rat deep brain imaging.

    Science.gov (United States)

    Giustetto, Pierangela; Filippi, Miriam; Castano, Mauro; Terreno, Enzo

    2015-03-02

    Photoacoustics and high frequency ultrasound stands out as powerful tools for neurobiological applications enabling high-resolution imaging on the central nervous system of small animals. However, transdermal and transcranial neuroimaging is frequently affected by low sensitivity, image aberrations and loss of space resolution, requiring scalp or even skull removal before imaging. To overcome this challenge, a new protocol is presented to gain significant insights in brain hemodynamics by photoacoustic and high-frequency ultrasounds imaging with the animal skin and skull intact. The procedure relies on the passage of ultrasound (US) waves and laser directly through the fissures that are naturally present on the animal cranium. By juxtaposing the imaging transducer device exactly in correspondence to these selected areas where the skull has a reduced thickness or is totally absent, one can acquire high quality deep images and explore internal brain regions that are usually difficult to anatomically or functionally describe without an invasive approach. By applying this experimental procedure, significant data can be collected in both sonic and optoacoustic modalities, enabling to image the parenchymal and the vascular anatomy far below the head surface. Deep brain features such as parenchymal convolutions and fissures separating the lobes were clearly visible. Moreover, the configuration of large and small blood vessels was imaged at several millimeters of depth, and precise information were collected about blood fluxes, vascular stream velocities and the hemoglobin chemical state. This repertoire of data could be crucial in several research contests, ranging from brain vascular disease studies to experimental techniques involving the systemic administration of exogenous chemicals or other objects endowed with imaging contrast enhancement properties. In conclusion, thanks to the presented protocol, the US and PA techniques become an attractive noninvasive

  17. Non-invasive diagnosis of H pylori infection: Evaluation of serological tests with and without current infection marker CIM

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To evaluate the performance of commercially available immunochromatographic (ICT) and immunoblot tests covering the current infection marker CIM and conventional ELISA for the diagnosis of Hpylori infection in adult dyspeptic patients. METHODS: Consecutive non-treated dyspeptic patients undergoing diagnostic endoscopy were tested for H pylori infection by culture, rapid urease test, and histology of gastric biopsy specimens. Serum from 61 H pylori infected and 21 non-infected patients were tested for anti-H pylori IgG antibodies by commercial ELISA (Accu Bind TM ELISA, Monobind, USA), ICT(Assure(R) H pylori Rapid Test, Genelabs Diagnostics, Singapore),and immunoblot (Helico Blot 2.1,Genelabs Diagnostics, Singapore) assays. ICT and immunoblot kits cover CIN among other parameters and their performance with and without CIM was evaluated separately. RESULTS: Sensitivity, specificity, positive predictive value (PPV),negative predictive value (NPV),and accuracy of ELISA were 96.7%,42.8%,83.1%,81.8%,and 82.9%,of ICT were 90.1%,80.9%,93.2%,73.9%,and 87.8%,of ICE with CIM were 88.5%,90.4%,96.4%,73.0%,and 89.0%,of immunoblot were 98.3%,80.9%,93.7%,94.4%,and 93.9%,and of immunoblot with CIM were 98.3%,90.4%,96.7%,95.0%,and 96.3%,respectively.CONCLUSION:Immunoblot with CIM had the best performance. ICE with CIM was found to be more specific and accurate than the conventional ELISA and may be useful for non-invasive diagnosis of H pylori infection.

  18. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography

    DEFF Research Database (Denmark)

    Vavere, Andrea L; Simon, Gregory G; George, Richard T

    2013-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability...... to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess...... the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8...

  19. Lymphoma: current status of clinical and preclinical imaging with radiolabeled antibodies

    Energy Technology Data Exchange (ETDEWEB)

    England, Christopher G. [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI (United States); Rui, Lixin [University of Wisconsin School of Medicine and Public Health, Department of Medicine, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Carbone Cancer Center, Madison, WI (United States); Cai, Weibo [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Carbone Cancer Center, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

    2017-03-15

    Lymphoma is a complex disease that arises from cells of the immune system with an intricate pathology. While lymphoma may be classified as Hodgkin or non-Hodgkin, each type of tumor is genetically and phenotypically different and highly invasive tissue biopsies are the only method to investigate these differences. Noninvasive imaging strategies, such as immunoPET, can provide a vital insight into disease staging, monitoring treatment response in patients, and dose planning in radioimmunotherapy. ImmunoPET imaging with radiolabeled antibody-based tracers may also assist physicians in optimizing treatment strategies and enhancing patient stratification. Currently, there are two common biomarkers for molecular imaging of lymphoma, CD20 and CD30, both of which have been considered for investigation in preclinical imaging studies. In this review, we examine the current status of both preclinical and clinical imaging of lymphoma using radiolabeled antibodies. Additionally, we briefly investigate the role of radiolabeled antibodies in lymphoma therapy. As radiolabeled antibodies play critical roles in both imaging and therapy of lymphoma, the development of novel antibodies and the discovery of new biomarkers may greatly affect lymphoma imaging and therapy in the future. (orig.)

  20. Non-invasive molecular imaging of fibrosis using a collagen-targeted peptidomimetic of the platelet collagen receptor glycoprotein VI.

    Directory of Open Access Journals (Sweden)

    Julien Muzard

    Full Text Available BACKGROUND: Fibrosis, which is characterized by the pathological accumulation of collagen, is recognized as an important feature of many chronic diseases, and as such, constitutes an enormous health burden. We need non-invasive specific methods for the early diagnosis and follow-up of fibrosis in various disorders. Collagen targeting molecules are therefore of interest for potential in vivo imaging of fibrosis. In this study, we developed a collagen-specific probe using a new approach that takes advantage of the inherent specificity of Glycoprotein VI (GPVI, the main platelet receptor for collagens I and III. METHODOLOGY/PRINCIPAL FINDINGS: An anti-GPVI antibody that neutralizes collagen-binding was used to screen a bacterial random peptide library. A cyclic motif was identified, and the corresponding peptide (designated collagelin was synthesized. Solid-phase binding assays and histochemical analysis showed that collagelin specifically bound to collagen (Kd 10(-7 M in vitro, and labelled collagen fibers ex vivo on sections of rat aorta and rat tail. Collagelin is therefore a new specific probe for collagen. The suitability of collagelin as an in vivo probe was tested in a rat model of healed myocardial infarctions (MI. Injecting Tc-99m-labelled collagelin and scintigraphic imaging showed that uptake of the probe occurred in the cardiac area of rats with MI, but not in controls. Post mortem autoradiography and histological analysis of heart sections showed that the labeled areas coincided with fibrosis. Scintigraphic molecular imaging with collagelin provides high resolution, and good contrast between the fibrotic scars and healthy tissues. The capacity of collagelin to image fibrosis in vivo was confirmed in a mouse model of lung fibrosis. CONCLUSION/SIGNIFICANCE: Collagelin is a new collagen-targeting agent which may be useful for non-invasive detection of fibrosis in a broad spectrum of diseases.

  1. Gynecologic imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    Iyer V

    2010-01-01

    Full Text Available Common diagnostic challenges in gynecology and the role of imaging in their evaluation are reviewed. Etiologies of abnormal uterine bleeding identified on pelvic sonography and sonohysterography are presented. An algorithmic approach for characterizing an incidentally detected adnexal mass and use of magnetic resonance imaging for definitive diagnosis are discussed. Finally, the role of F18-fluorodeoxyglucose positron emission tomography in the management of gynecological malignancies, and pitfalls associated with their use are examined.

  2. Current concepts on imaging in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lecchi, Michela; Elisei, Federica; Lucignani, Giovanni [University of Milan, Institute of Radiological Sciences, Milan (Italy); San Paolo Hospital, Unit of Nuclear Medicine, Milan (Italy); Fossati, Piero [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); Orecchia, Roberto [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); European Institute of Oncology, Department of Radiation Oncology, Milan (Italy)

    2008-04-15

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy. (orig.)

  3. Current concepts on imaging in radiotherapy.

    Science.gov (United States)

    Lecchi, Michela; Fossati, Piero; Elisei, Federica; Orecchia, Roberto; Lucignani, Giovanni

    2008-04-01

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.

  4. Real-time noninvasive optical imaging of exercising muscle and brain upon cognitive stimuli

    Science.gov (United States)

    Quaresima, Valentina; van der Sluijs, Marco C.; Menssen, Jan; Grillotti, Lucia; Ferrari, Marco; Colier, Willy N.

    2001-06-01

    The monitoring of a single muscle location does not reflect the heterogeneity of the muscle groups activation during exercise. In the past, measurements of oxygen consumption (VO2) at single muscle locations could be carried out non-invasively by near-infrared continuous wave spectroscopy (NIRCWS) at rest or during isometric contractions. In the present study, human regional quadriceps (vastus lateralis and rectus femoris) VO2 was investigated at rest and during maximal voluntary contractions using a 12- channel NIRCWS system with an acquisition time of 0.1 s.

  5. Current and future trends in imaging informatics for oncology.

    Science.gov (United States)

    Levy, Mia A; Rubin, Daniel L

    2011-01-01

    Clinical imaging plays an essential role in cancer care and research for diagnosis, prognosis, and treatment response assessment. Major advances in imaging informatics to support medical imaging have been made during the last several decades. More recent informatics advances focus on the special needs of oncologic imaging, yet gaps still remain. We review the current state, limitations, and future trends in imaging informatics for oncology care including clinical and clinical research systems. We review information systems to support cancer clinical workflows including oncologist ordering of radiology studies, radiologist review and reporting of image findings, and oncologist review and integration of imaging information for clinical decision making. We discuss informatics approaches to oncologic imaging including, but not limited to, controlled terminologies, image annotation, and image-processing algorithms. With the ongoing development of novel imaging modalities and imaging biomarkers, we expect these systems will continue to evolve and mature.

  6. Noninvasive imaging of tumor hypoxia in rats using the 2-nitroimidazole {sup 18}F-EF5

    Energy Technology Data Exchange (ETDEWEB)

    Ziemer, L.S. [University of Pennsylvania School of Veterinary Medicine, Section of Radiology, 3850 Spruce Street, Philadelphia, PA 19104 (United States); Evans, S.M.; Kachur, A.V.; Shuman, A.L.; Cardi, C.A.; Jenkins, W.T.; Karp, J.S.; Alavi, A.; Koch, C.J. [School of Medicine, University of Pennsylvania, Philadelphia (United States); Dolbier Jr., W.R. [Department of Chemistry, University of Florida, Gainesville, Florida (United States)

    2003-02-01

    Tumor hypoxia is an important prognostic indicator for cancer therapy outcome. EF5 2-(2-nitro-1[H]-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide has been employed to measure tumor hypoxia in animals and humans using immunohistochemical methods. EF5 is a lipophilic molecule designed to have a very uniform biodistribution, a feature of obvious benefit for use in PET imaging. The present study represents the first demonstration of noninvasive PET imaging of rat tumors using fluorine-18 labeled EF5. Because of the small tumor size, partial volume effects may result in underestimation of concentration of the compound. Therefore, validation of the PET data was performed by gamma counting of the imaged tissue. The tumor models studied were the Morris 7777 (Q7) hepatoma (n=5) and the 9L glioma (n=2) grown subcutaneously in rats. Our previous studies have demonstrated that early passage 9L tumors are not severely hypoxic and that Q7 tumors are characterized by heterogeneous regions of tumor hypoxia (i.e., Q7 tumors are usually more hypoxic than early passage 9L tumors). The seven rats were imaged in the HEAD Penn-PET scanner at various time points after administration of 50-100 {mu}Ci {sup 18}F-EF5 in 30 mg/kg carrier nonradioactive EF5. The carrier was used to ensure drug biodistribution comparable to prior studies using immunohistochemical methods. {sup 18}F-EF5 was excreted primarily via the urinary system. Images obtained 10 min following drug administration demonstrated that the EF5 distributed evenly to all organ systems, including brain. Later images showed increased uptake in most Q7 tumors compared with muscle. Liver uptake remained relatively constant over the same time periods. Tumor to muscle ratios ranged from 0.82 to 1.73 (based on PET images at 120 min post injection) and 1.47 to 2.95 (based on gamma counts at 180 min post injection). Tumors were easily visible by 60 min post injection when the final tumor to muscle ratios (based on gamma counts

  7. Utility of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) to non-invasively diagnose burn depth in a porcine model.

    Science.gov (United States)

    Burmeister, David M; Ponticorvo, Adrien; Yang, Bruce; Becerra, Sandra C; Choi, Bernard; Durkin, Anthony J; Christy, Robert J

    2015-09-01

    Surgical intervention of second degree burns is often delayed because of the difficulty in visual diagnosis, which increases the risk of scarring and infection. Non-invasive metrics have shown promise in accurately assessing burn depth. Here, we examine the use of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) for predicting burn depth. Contact burn wounds of increasing severity were created on the dorsum of a Yorkshire pig, and wounds were imaged with SFDI/LSI starting immediately after-burn and then daily for the next 4 days. In addition, on each day the burn wounds were biopsied for histological analysis of burn depth, defined by collagen coagulation, apoptosis, and adnexal/vascular necrosis. Histological results show that collagen coagulation progressed from day 0 to day 1, and then stabilized. Results of burn wound imaging using non-invasive techniques were able to produce metrics that correlate to different predictors of burn depth. Collagen coagulation and apoptosis correlated with SFDI scattering coefficient parameter [Formula: see text] and adnexal/vascular necrosis on the day of burn correlated with blood flow determined by LSI. Therefore, incorporation of SFDI scattering coefficient and blood flow determined by LSI may provide an algorithm for accurate assessment of the severity of burn wounds in real time. Published by Elsevier Ltd.

  8. Utility of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) to non-invasively diagnose burn depth in a porcine model☆

    Science.gov (United States)

    Burmeister, David M.; Ponticorvo, Adrien; Yang, Bruce; Becerra, Sandra C.; Choi, Bernard; Durkin, Anthony J.; Christy, Robert J.

    2015-01-01

    Surgical intervention of second degree burns is often delayed because of the difficulty in visual diagnosis, which increases the risk of scarring and infection. Non-invasive metrics have shown promise in accurately assessing burn depth. Here, we examine the use of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) for predicting burn depth. Contact burn wounds of increasing severity were created on the dorsum of a Yorkshire pig, and wounds were imaged with SFDI/LSI starting immediately after-burn and then daily for the next 4 days. In addition, on each day the burn wounds were biopsied for histological analysis of burn depth, defined by collagen coagulation, apoptosis, and adnexal/vascular necrosis. Histological results show that collagen coagulation progressed from day 0 to day 1, and then stabilized. Results of burn wound imaging using non-invasive techniques were able to produce metrics that correlate to different predictors of burn depth. Collagen coagulation and apoptosis correlated with SFDI scattering coefficient parameter ( μs′) and adnexal/vascular necrosis on the day of burn correlated with blood flow determined by LSI. Therefore, incorporation of SFDI scattering coefficient and blood flow determined by LSI may provide an algorithm for accurate assessment of the severity of burn wounds in real time. PMID:26138371

  9. Current MR imaging of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sae Lin; Sung, Seuk Jae [Dept. of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of)

    2016-08-15

    Renal cell carcinoma (RCC) consists of approximately 85-90% of renal masses, and its incidence is increasing due to widespread use of modern imaging modalities such as ultrasonography or computed tomography. Computed tomography has served an important role in the diagnosis and staging of RCC; however, recent advances in magnetic resonance imaging (MRI) techniques have considerably improved our ability to predict tumor biology beyond the morphologic assessment. Multiparametric MRI protocols include standard sequences tailored for the morphologic evaluation and acquisitions that provide information about the tumor microenvironment such as diffusion-weighted imaging and dynamic contrast-enhanced MRI. The role of multiparametric MRI in the evaluation of RCC now extends to preoperative characterization of RCC subtypes, histologic grade, and quantitative assessment of tumor response to targeted therapies in patients with metastatic disease. Herein, the clinical applications and recent advances in MRI applied to RCC are reviewed along with its merits and demerits. We aimed to review MRI techniques and image analysis that can improve the management of patients with RCC. Familiarity with the advanced MRI techniques and various imaging findings of RCC would also facilitate optimal clinical recommendations for patients.

  10. A dual-modality photoacoustic and ultrasound imaging system for noninvasive sentinel lymph node detection: preliminary clinical results

    Science.gov (United States)

    Erpelding, Todd N.; Garcia-Uribe, Alejandro; Krumholz, Arie; Ke, Haixin; Maslov, Konstantin; Appleton, Catherine; Margenthaler, Julie; Wang, Lihong V.

    2014-03-01

    Sentinel lymph node biopsy (SLNB) has emerged as an accurate, less invasive alternative to axillary lymph node dissection, and it has rapidly become the standard of care for patients with clinically node-negative breast cancer. The sentinel lymph node (SLN) hypothesis states that the pathological status of the axilla can be accurately predicted by determining the status of the first (i.e., sentinel) lymph nodes that drain from the primary tumor. Physicians use radio-labeled sulfur colloid and/or methylene blue dye to identify the SLN, which is most likely to contain metastatic cancer cells. However, the surgical procedure causes morbidity and associated expenses. To overcome these limitations, we developed a dual-modality photoacoustic and ultrasound imaging system to noninvasively detect SLNs based on the accumulation of methylene blue dye. Ultimately, we aim to guide percutaneous needle biopsies and provide a minimally invasive method for axillary staging of breast cancer. The system consists of a tunable dye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22), and a multichannel data acquisition system which displays co-registered photoacoustic and ultrasound images in real-time. Our clinical results demonstrate that real-time photoacoustic imaging can provide sensitive and specific detection of methylene blue dye in vivo. While preliminary studies have shown that in vivo detection of SLNs by using co-registered photoacoustic and ultrasound imaging is feasible, further investigation is needed to demonstrate robust SLN detection.

  11. Near-infrared quantum-dot-based non-invasive in vivo imaging of squamous cell carcinoma U14

    Energy Technology Data Exchange (ETDEWEB)

    Cao Yu' an; Yang Kai; Li Zhigang; Zhao Cheng; Yang Jia [Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016 (China); Shi Chunmeng, E-mail: cqfyyk@yahoo.com.cn [Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Road, Chongqing 400038 (China)

    2010-11-26

    Near-infrared (near-ir) quantum dots (QDs) are well known for their excellent optical characteristics. They hold great potential for applications in non-invasive long term observation and tracing of cells in vivo. Here, near-ir QDs with an emission wavelength of 800 nm (QD800) were used to label squamous cell carcinoma cell line U14 (U14/QD800). The effect of tissue depth and animal fur on the imaging sensitivity and stability was evaluated following subcutaneous and intramuscular injection into Kunming mice, employing an in vivo imaging system. We have demonstrated that QD800-based visual in vivo imaging increased the sensitivity of cancer early detection by a factor of 100 compared with traditional detection methods. More importantly, this study proved for the first time that animal fur has a serious impact on the detection sensitivity and duration of QD-based in vivo imaging. In general, the duration and sensitivity of QD800 for in vivo imaging were not greatly affected by a depth less than 1.8 {+-} 0.21 mm (subcutaneous or intramuscular). This study provides critical reference data for further research on near-ir QD-based early detection and in vivo visual observation of cancer.

  12. Complementarity of variable-magnification and spectral-separation fluorescence imaging systems for noninvasive detection of metastasis and intravital detection of single cancer cells in mouse models.

    Science.gov (United States)

    Zhang, Yong; Hiroshima, Yukihiko; Ma, Huaiyu; Zhang, Nan; Zhao, Ming; Hoffman, Robert M

    2015-02-01

    Imaging of tumor growth, progression and metastasis with fluorescent proteins in mouse models is a powerful technology. A limit to fluorescent-protein imaging has been for non-invasive deep-seated tumors, such as those in the lung. In the present study, the Maestro spectral-separation fluorescence imaging system and the OV100 variable-magnification imaging system were compared for noninvasive detection of metastasis in fluorescent protein-expressing orthotopic lung, liver, pancreas, and colon cancer in nude mouse tumor models, as well as for intravital single-cell imaging. Sensitivity, multispectral capability, contrast, and single cell resolution were investigated. The Maestro system outperformed the OV100 for noninvasive imaging of primary and metastatic tumors. The Maestro system detected brain tumor metastasis five days earlier than did the OV100. The Maestro had greater depth of detection compared with the OV100. By separating skin and food autofluorescence, the Maestro provided high-contrast images. The Maestro system was able to produce composite images with more unmixed components and detected more different color signals simultaneously than did the OV100. However, the OV100 system had higher resolution and was able to detect single cells in vivo unlike the Maestro. The present study demonstrates that the two instruments are complementary for imaging of all stages of cancer in mice, including single-cell trafficking and the superiority of in vivo fluorescent-protein imaging over luciferase imaging.

  13. Non-invasive single-shot 3D imaging through a scattering layer using speckle interferometry

    CERN Document Server

    Somkuwar, Atul S; R., Vinu; Park, Yongkeun; Singh, Rakesh Kumar

    2015-01-01

    Optical imaging through complex scattering media is one of the major technical challenges with important applications in many research fields, ranging from biomedical imaging, astronomical telescopy, and spatially multiplex optical communications. Although various approaches for imaging though turbid layer have been recently proposed, they had been limited to two-dimensional imaging. Here we propose and experimentally demonstrate an approach for three-dimensional single-shot imaging of objects hidden behind an opaque scattering layer. We demonstrate that under suitable conditions, it is possible to perform the 3D imaging to reconstruct the complex amplitude of objects situated at different depths.

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

    Science.gov (United States)

    Pain, Bedabrata; Cunningham, Thomas; Hancock, Bruce

    2008-01-01

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

  15. High-Resolution, Non-Invasive Imaging of Upper Vocal Tract Articulators Compatible with Human Brain Recordings.

    Directory of Open Access Journals (Sweden)

    Kristofer E Bouchard

    Full Text Available A complete neurobiological understanding of speech motor control requires determination of the relationship between simultaneously recorded neural activity and the kinematics of the lips, jaw, tongue, and larynx. Many speech articulators are internal to the vocal tract, and therefore simultaneously tracking the kinematics of all articulators is nontrivial--especially in the context of human electrophysiology recordings. Here, we describe a noninvasive, multi-modal imaging system to monitor vocal tract kinematics, demonstrate this system in six speakers during production of nine American English vowels, and provide new analysis of such data. Classification and regression analysis revealed considerable variability in the articulator-to-acoustic relationship across speakers. Non-negative matrix factorization extracted basis sets capturing vocal tract shapes allowing for higher vowel classification accuracy than traditional methods. Statistical speech synthesis generated speech from vocal tract measurements, and we demonstrate perceptual identification. We demonstrate the capacity to predict lip kinematics from ventral sensorimotor cortical activity. These results demonstrate a multi-modal system to non-invasively monitor articulator kinematics during speech production, describe novel analytic methods for relating kinematic data to speech acoustics, and provide the first decoding of speech kinematics from electrocorticography. These advances will be critical for understanding the cortical basis of speech production and the creation of vocal prosthetics.

  16. High-Resolution, Non-Invasive Imaging of Upper Vocal Tract Articulators Compatible with Human Brain Recordings

    Science.gov (United States)

    Anumanchipalli, Gopala K.; Dichter, Benjamin; Chaisanguanthum, Kris S.; Johnson, Keith; Chang, Edward F.

    2016-01-01

    A complete neurobiological understanding of speech motor control requires determination of the relationship between simultaneously recorded neural activity and the kinematics of the lips, jaw, tongue, and larynx. Many speech articulators are internal to the vocal tract, and therefore simultaneously tracking the kinematics of all articulators is nontrivial—especially in the context of human electrophysiology recordings. Here, we describe a noninvasive, multi-modal imaging system to monitor vocal tract kinematics, demonstrate this system in six speakers during production of nine American English vowels, and provide new analysis of such data. Classification and regression analysis revealed considerable variability in the articulator-to-acoustic relationship across speakers. Non-negative matrix factorization extracted basis sets capturing vocal tract shapes allowing for higher vowel classification accuracy than traditional methods. Statistical speech synthesis generated speech from vocal tract measurements, and we demonstrate perceptual identification. We demonstrate the capacity to predict lip kinematics from ventral sensorimotor cortical activity. These results demonstrate a multi-modal system to non-invasively monitor articulator kinematics during speech production, describe novel analytic methods for relating kinematic data to speech acoustics, and provide the first decoding of speech kinematics from electrocorticography. These advances will be critical for understanding the cortical basis of speech production and the creation of vocal prosthetics. PMID:27019106

  17. Noninvasive imaging of in vivo MuRF1 expression during muscle atrophy.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Numerous human diseases can lead to atrophy of skeletal muscle, and loss of this tissue has been correlated with increased mortality and morbidity rates. Clinically addressing muscle atrophy remains an unmet medical need, and the development of preclinical tools to assist drug discovery and basic research in this effort is important for advancing this goal. In this report, we describe the development of a bioluminescent gene reporter rat, based on the zinc finger nuclease-targeted insertion of a bicistronic luciferase reporter into the 3' untranslated region of a muscle specific E3 ubiquitin ligase gene, MuRF1 (Trim63. In longitudinal studies, we noninvasively assess atrophy-related expression of this reporter in three distinct models of muscle loss (sciatic denervation, hindlimb unloading and dexamethasone-treatment and show that these animals are capable of generating refined detail on in vivo MuRF1 expression with high temporal and anatomical resolution.

  18. Current concepts in imaging of tendinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Robert S.D.; Grainger, Andrew J

    2001-04-01

    With the rising popularity of recreational sports, radiologists are being asked to image tendons with increasing frequency. Recognition of the critical link tendons provide between muscle and bone has also led to a better understanding of the processes leading to tendon damage. While plain radiography and CT have only a limited role to play in the diagnosis of tendon abnormality, the improvements in ultrasound and MRI technology mean that tendons can now be demonstrated in exquisite detail and previously undetectable abnormalities are readily demonstrated. This article reviews the structure and pathological processes affecting tendons and discusses the role of imaging in their assessment with an emphasis on ultrasound and MRI. Campbell, R.S.D. and Grainger, A.J. (2001)

  19. Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis.

    Science.gov (United States)

    Greening, Gage J; Rajaram, Narasimhan; Muldoon, Timothy J

    2016-10-17

    Recent fiber-bundle microendoscopy techniques enable non-invasive analysis of in vivo tissue using either imaging techniques or a combination of spectroscopy techniques. Combining imaging and spectroscopy techniques into a single optical probe may provide a more complete analysis of tissue health. In this article, two dissimilar modalities are combined, high-resolution fluorescence microendoscopy imaging and diffuse reflectance spectroscopy, into a single optical probe. High-resolution fluorescence microendoscopy imaging is a technique used to visualize apical tissue micro-architecture and, although mostly a qualitative technique, has demonstrated effective real-time differentiation between neoplastic and non-neoplastic tissue. Diffuse reflectance spectroscopy is a technique which can extract tissue physiological parameters including local hemoglobin concentration, melanin concentration, and oxygen saturation. This article describes the specifications required to construct the fiber-optic probe, how to build the instrumentation, and then demonstrates the technique on in vivo human skin. This work revealed that tissue micro-architecture, specifically apical skin keratinocytes, can be co-registered with its associated physiological parameters. The instrumentation and fiber-bundle probe presented here can be optimized as either a handheld or endoscopically-compatible device for use in a variety of organ systems. Additional clinical research is needed to test the viability of this technique for different epithelial disease states.

  20. Current status of radionuclide scrotal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Holder, L.E.; Melloul, M.; Chen, D.

    1981-10-01

    Scrotal imaging with technetium-99m sodium pertechnetate consists of a radionuclide angiogram and static scrotal scans. Utilization of this study in patients presenting with an acute scrotum can dramatically reduce the number of surgical explorations for acute epididymitis. It can also aid in other aspects of differential diagnosis in patients presenting with either an acutely enlarged and/or painful scrotum or a scrotal mass. Ambiguities in previous descriptions of perfusion through the spermatic and extraspermatic cord vessels are described and distinguished from scrotal perfusion. The clinical and scintigraphic spectrum of testicular torsion, including spontaneous detorsion, early acute testicular torsion, midphase testicular torsion, and late phase or ''missed testicular torsion,'' is discussed and illustrated. The variety of patterns seen in acute epididymitis, including lateral and medial epididymal location, and focal epididymitis are described, as is the appearance of hydrocele as both a primary and secondary entity. The relationship of scrotal imaging to the overall clinical presentation and evaluation of these patients is emphasized in testicular torsion, torsion of the testicular appendages, epididymitis, abscess, trauma, tumor, spermatocele, and varicocele. The techniques, clinical utility, and relationship to radionuclide imaging of Doppler ultrasound and gray scale ultrasound scanning are reviewed. Doppler ultrasound results in many false negative studies in testicular torsion. Gray scale ultrasound is useful in clarifying the nature of scrotal masses.

  1. Nanoscale Imaging of Current Density with a Single-Spin Magnetometer.

    Science.gov (United States)

    Chang, K; Eichler, A; Rhensius, J; Lorenzelli, L; Degen, C L

    2017-03-24

    Charge transport in nanostructures and thin films is fundamental to many phenomena and processes in science and technology, ranging from quantum effects and electronic correlations in mesoscopic physics, to integrated charge- or spin-based electronic circuits, to photoactive layers in energy research. Direct visualization of the charge flow in such structures is challenging due to their nanometer size and the itinerant nature of currents. In this work, we demonstrate noninvasive magnetic imaging of current density in two-dimensional conductor networks including metallic nanowires and carbon nanotubes. Our sensor is the electronic spin of a diamond nitrogen-vacancy center attached to a scanning tip and operated under ambient conditions. Using a differential measurement technique, we detect DC currents down to a few μA with a current density noise floor of ∼2 × 10(4) A/cm(2). Reconstructed images have a spatial resolution of typically 50 nm, with a best-effort value of 22 nm. Current density imaging offers a new route for studying electronic transport and conductance variations in two-dimensional materials and devices, with many exciting applications in condensed matter physics and materials science.

  2. ARRAY PULSED EDDY CURRENT IMAGING SYSTEM USED TO DETECT CORROSION

    Institute of Scientific and Technical Information of China (English)

    Yang Binfeng; Luo Feilu; Cao Xiongheng; Xu Xiaojie

    2005-01-01

    A theory model is established to describe the voltage-current response function. The peak amplitude and the zero-crossing time of the transient signal is extracted as the imaging features, array pulsed eddy current (PEC) imaging is proposed to detect corrosion. The test results show that this system has the advantage of fast scanning speed, different imaging mode and quantitative detection, it has a broad application in the aviation nondestructive testing.

  3. Noninvasive Label-Free Detection of Micrometastases in the Lymphatics with Ultrasound-Guided Photoacoustic Imaging

    Science.gov (United States)

    2015-10-01

    Ultrasound and Photoacoustic Imaging of Anatomical and Functional Indicators of Lymph Node Metastasis,” Biomedical Engineering Society Annual Meeting...imaging system that will detect functional changes associated with lymph node metastasis in breast cancer patients. Our efforts in the first year have...imaging can be used to guide dissection . We have also successfully integrated a programmable ultrasound machine (Verasonics Vantage) and tunable pulsed

  4. Bladder exstrophy: current management and postoperative imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pierre, Ketsia [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Borer, Joseph [Boston Children' s Hospital, Department of Urology, Boston, MA (United States); Phelps, Andrew [University of California, San Francisco, Department of Pediatric Radiology, San Francisco, CA (United States); Chow, Jeanne S. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Boston Children' s Hospital, Department of Urology, Boston, MA (United States)

    2014-07-15

    Bladder exstrophy is a rare malformation characterized by an infra-umbilical abdominal wall defect, incomplete closure of the bladder with mucosa continuous with the abdominal wall, epispadias, and alterations in the pelvic bones and muscles. It is part of the exstrophy-epispadias complex, with cloacal exstrophy on the severe and epispadias on the mild ends of the spectrum. Bladder exstrophy is the most common of these entities and is more common in boys. The goal of this paper is to describe common methods of repair and to provide an imaging review of the postoperative appearances. (orig.)

  5. Asynchrony of the early maturation of white matter bundles in healthy infants: Quantitative landmarks revealed noninvasively by diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, J.; Perrin, M.; Mangin, J.F.; Cointepas, Y.; Duchesnay, E.; Le Bihan, D.; Hertz-Pannier, L. [CEA, Serv Hosp Frederic Joliot, UNAF, F-91406 Orsay (France); Dehaene-Lambertz, G. [INSERM, U562, Orsay (France); Dubois, J.; Dehaene-Lambertz, G.; Perrin, M.; Mangin, J.F.; Cointepas, Y.; Duchesnay, E.; Le Bihan, D.; Hertz-Pannier, L. [IFR49, Paris (France)

    2008-07-01

    Normal cognitive development in infants follows a well-known temporal sequence, which is assumed to be correlated with the structural maturation of underlying functional networks. Postmortem studies and, more recently, structural MR imaging studies have described qualitatively the heterogeneous spatio-temporal progression of white matter myelination. However, in vivo quantification of the maturation phases of fiber bundles is still lacking. We used noninvasive diffusion tensor MR imaging and tractography in twenty-three 1-4-month-old healthy infants to quantify the early maturation of the main cerebral fascicles. A specific maturation model, based on the respective roles of different maturational processes on the diffusion phenomena, was designed to highlight asynchronous maturation across bundles by evaluating the time-course of mean diffusivity and anisotropy changes over the considered developmental period. Using an original approach, a progression of maturation in four relative stages was determined in each tract by estimating the maturation state and speed, from the diffusion indices over the infants group compared with an adults group on one hand, and in each tract compared with the average over bundles on the other hand. Results were coherent with, and extended previous findings in 8 of 11 bundles, showing the anterior limb of the internal capsule and cingulum as the most immature, followed by the optic radiations, arcuate and inferior longitudinal fascicles, then the spino-thalamic tract and fornix, and finally the cortico-spinal tract as the most mature bundle. Thus, this approach provides new quantitative landmarks for further noninvasive research on brain-behavior relationships during normal and abnormal development. (authors)

  6. Image Information Retrieval: An Overview of Current Research

    Directory of Open Access Journals (Sweden)

    Abby A. Goodrum

    2000-01-01

    Full Text Available This paper provides an overview of current research in image information retrieval and provides an outline of areas for future research. The approach is broad and interdisciplinary and focuses on three aspects of image research (IR: text-based retrieval, content-based retrieval, and user interactions with image information retrieval systems. The review concludes with a call for image retrieval evaluation studies similar to TREC.

  7. Image Information Retrieval: An Overview of Current Research

    OpenAIRE

    Abby A. Goodrum

    2000-01-01

    This paper provides an overview of current research in image information retrieval and provides an outline of areas for future research. The approach is broad and interdisciplinary and focuses on three aspects of image research (IR): text-based retrieval, content-based retrieval, and user interactions with image information retrieval systems. The review concludes with a call for image retrieval evaluation studies similar to TREC.

  8. Non-invasive quantitative pulmonary V/Q imaging using Fourier decomposition MRI at 1.5T

    Energy Technology Data Exchange (ETDEWEB)

    Kjoerstad, Aasmund; Corteville, Dominique M.R.; Zoellner, Frank G.; Schad, Lothar R. [Heidelberg Univ., Medical Faculty Mannheim (Germany). Computer Assisted Clinical Medicine; Henzler, Thomas [Heidelberg Univ., Medical Faculty Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine; Schmid-Bindert, Gerald [Heidelberg Univ., Medical Faculty Mannheim (Germany). Interdisciplinary Thoracic Oncology

    2015-07-01

    Techniques for quantitative pulmonary perfusion and ventilation using the Fourier Decomposition method were recently demonstrated. We combine these two techniques and show that ventilation-perfusion (V/Q) imaging is possible using only a single MR acquisition of less than thirty seconds. The Fourier Decomposition method is used in combination with two quantification techniques, which extract baselines from within the images themselves and thus allows quantification. For the perfusion, a region assumed to consist of 100% blood is utilized, while for the ventilation the zero-frequency component is used. V/Q-imaging is then done by dividing the quantified ventilation map with the quantified perfusion map. The techniques were used on ten healthy volunteers and fifteen patients diagnosed with lung cancer. A mean V/Q-ratio of 1.15±0.22 was found for the healthy volunteers and a mean V/Q-ratio of 1.93±0.83 for the non-afflicted lung in the patients. Mean V/Q-ratio in the afflicted (tumor-bearing) lung was found to be 1.61±1.06. Functional defects were clearly visible in many of the patient images, but 5 of 15 patient images had to be excluded due to artifacts or low SNR, indicating a lack of robustness. Conclusion Non-invasive, quantitative V/Q-imaging is possible using Fourier Decomposition MRI. The method requires only a single acquisition of less than 30 seconds, but robustness in patients remains an issue.

  9. Wavelength-Modulated Differential Photoacoustic (WM-DPA) imaging: a high dynamic range modality towards noninvasive diagnosis of cancer

    Science.gov (United States)

    Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

    2016-03-01

    This study explores wavelength-modulated differential photo-acoustic (WM-DPA) imaging for non-invasive early cancer detection via sensitive characterization of functional information such as hemoglobin oxygenation (sO2) levels. Well-known benchmarks of tumor formation such as angiogenesis and hypoxia can be addressed this way. While most conventional photo-acoustic imaging has almost entirely employed high-power pulsed lasers, frequency-domain photo-acoustic radar (FD-PAR) has seen significant development as an alternative technique. It employs a continuous wave laser source intensity-modulated and driven by frequency-swept waveforms. WM-DPA imaging utilizes chirp modulated laser beams at two distinct wavelengths for which absorption differences between oxy- and deoxygenated hemoglobin are minimum (isosbestic point, 805 nm) and maximum (680 nm) to simultaneously generate two signals detected using a standard commercial array transducer as well as a single-element transducer that scans the sample. Signal processing is performed using Lab View and Matlab software developed in-house. Minute changes in total hemoglobin concentration (tHb) and oxygenation levels are detectable using this method since background absorption is suppressed due to the out-of-phase modulation of the laser sources while the difference between the two signals is amplified, thus allowing pre-malignant tumors to become identifiable. By regulating the signal amplitude ratio and phase shift the system can be tuned to applications like cancer screening, sO2 quantification and hypoxia monitoring in stroke patients. Experimental results presented demonstrate WM-DPA imaging of sheep blood phantoms in comparison to single-wavelength FD-PAR imaging. Future work includes the functional PA imaging of small animals in vivo.

  10. Multispectral imaging approach for simplified non-invasive in-vivo evaluation of gingival erythema

    Science.gov (United States)

    Eckhard, Timo; Valero, Eva M.; Nieves, Juan L.; Gallegos-Rueda, José M.; Mesa, Francisco

    2012-03-01

    Erythema is a common visual sign of gingivitis. In this work, a new and simple low-cost image capture and analysis method for erythema assessment is proposed. The method is based on digital still images of gingivae and applied on a pixel-by-pixel basis. Multispectral images are acquired with a conventional digital camera and multiplexed LED illumination panels at 460nm and 630nm peak wavelength. An automatic work-flow segments teeth from gingiva regions in the images and creates a map of local blood oxygenation levels, which relates to the presence of erythema. The map is computed from the ratio of the two spectral images. An advantage of the proposed approach is that the whole process is easy to manage by dental health care professionals in clinical environment.

  11. Subclinical hyperthyroidism: current concepts and scintigraphic imaging.

    Science.gov (United States)

    Intenzo, Charles; Jabbour, Serge; Miller, Jeffrey L; Ahmed, Intekhab; Furlong, Kevin; Kushen, Medina; Kim, Sung M; Capuzzi, David M

    2011-09-01

    Subclinical hyperthyroidism is defined as normal serum free thyroxine and a free triiodothyronine level, with a thyroid-stimulating hormone level suppressed below the normal range and is usually undetectable. Although patients with this diagnosis have no or few signs and symptoms of overt thyrotoxicosis, there is sufficient evidence that it is associated with a relatively higher risk of supraventricular arrhythmias as well as the acceleration or the development of osteoporosis. Consequently, the approach to the patient with subclinical hyperthyroidism is controversial, that is, therapeutic intervention versus watchful waiting. Regardless, it is imperative for the referring physician to identify the causative thyroid disorder. This is optimally accomplished by a functional study, namely scintigraphy. Recognition of the scan findings of the various causes of subclinical hyperthyroidism enables the imaging specialist to help in diagnosing the underlying condition causing thyroid-stimulating hormone suppression thereby facilitating the workup and management of this thyroid disorder.

  12. Research Techniques Made Simple: Noninvasive Imaging Technologies for the Delineation of Basal Cell Carcinomas.

    Science.gov (United States)

    Que, Syril Keena T

    2016-04-01

    In this article we discuss the development of noninvasive imaging modalities to help delineate tumor margins of basal cell carcinomas in the setting of Mohs micrographic surgery. A review of the available literature reveals that dermoscopy can help delineate basal cell carcinomas before surgical removal but that it has no benefit over clinical inspection in reducing the number of Mohs stages. In contrast, fluorescence confocal microscopy has a sensitivity of 88-96% and specificity of 89-99% for the detection of basal cell carcinomas and can potentially serve as a rapid means for tumor evaluation on ex vivo specimens. Optical coherence tomography has shown some success in the presurgical evaluation of tumor margins in vivo, before surgical excision. With ongoing developments in device portability, speed of image retrieval, and image resolution, these technologies are likely to gain traction in cutaneous oncology research and practice. It is therefore important for dermatology clinicians and researchers to understand the mechanisms, principal uses, advantages, and limitations of each device.

  13. The utilization of a non-invasive fluorescence imaging system to follow clinical dermatological MAL-PDT

    Science.gov (United States)

    Tyrrell, Jessica; Campbell, Sandra; Curnow, Alison

    2009-06-01

    This study employed a commercially available, non-invasive, fluorescence imaging system (Dyaderm, Biocam, Germany), to measure protoporphyrin IX (PpIX) concentration at several different stages during clinical dermatological methyl aminolevulinate photodynamic therapy (MAL-PDT). We validated the system prior to use to ensure that the PpIX changes witnessed were accurate and not due to environmental or user induced artifacts. The system was then employed to acquire color (morphological) and fluorescent (physiological) images simultaneously during dermatological PDT. Clinical data was collected from a range of licensed dermatological conditions (actinic keratosis, Bowen's disease and superficial basal cell carcinoma) during initial and subsequent PDT treatment cycles. The initial clinical data indicated that each type of licensed lesion considered responded in a similar manner following the application of Metvix (Galderma, U.K.) and the subsequent light irradiation (Aktilite, Galderma, U.K.). Images acquired three hours after Metvix application showed a significant increase in PpIX concentration within the lesion (P < 0.05), whilst PpIX levels in the surrounding normal tissue remained unaltered. After irradiation, the PpIX concentration was significantly decreased and returned to a level similar to the initial concentration originally observed. Lesions that received subsequent treatment cycles accumulated significantly less PpIX (P < 0.05) prior to irradiation.

  14. Noninvasive near-infrared fluorescent protein-based imaging of tumor progression and metastases in deep organs and intraosseous tissues

    Science.gov (United States)

    Jiguet-Jiglaire, Carine; Cayol, Mylène; Mathieu, Sylvie; Jeanneau, Charlotte; Bouvier-Labit, Corinne; Ouafik, L.'houcine; El-Battari, Assou

    2014-01-01

    Whole-body imaging of experimental tumor growth is more feasible within the near-infrared (NIR) optical window because of the highest transparency of mammalian tissues within this wavelength spectrum, mainly due to improved tissue penetration and lower autofluorescence. We took advantage from the recently cloned infrared fluorescent protein (iRFP) together with a human immunodeficiency virus (HIV)-based lentiviral vector to produce virally transduced tumor cells that permanently express this protein. We then noninvasively explored metastatic spread as well as primary tumor growth in deep organs and behind bone barriers. Intrabone tumor growth was investigated through intracranial and intratibial injections of glioblastoma and osteosarcoma cells, respectively, and metastasis was assessed by tail vein injection of melanoma cells. We found that the emitted fluorescence is captured as sharp images regardless of the organ or tissue considered. Furthermore, by overlaying fluorescence spots with the white light, it was possible to afford whole-body images yet never observed before. This approach allowed us to continuously monitor the growth and dissemination of tumor cells with a small number of animals, minimal animal handling, and without the need for any additive. This iRFP-based system provides high-resolution readouts of tumorigenesis that should greatly facilitate preclinical trials with anticancer therapeutic molecules.

  15. Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Borelli, Flavio Antonio de Oliveira, E-mail: fborelli@cardiol.br; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

    2013-11-15

    Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m{sup 2}. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

  16. Using multimodal imaging techniques to monitor limb ischemia: a rapid noninvasive method for assessing extremity wounds

    Science.gov (United States)

    Luthra, Rajiv; Caruso, Joseph D.; Radowsky, Jason S.; Rodriguez, Maricela; Forsberg, Jonathan; Elster, Eric A.; Crane, Nicole J.

    2013-03-01

    Over 70% of military casualties resulting from the current conflicts sustain major extremity injuries. Of these the majority are caused by blasts from improvised explosive devices. The resulting injuries include traumatic amputations, open fractures, crush injuries, and acute vascular disruption. Critical tissue ischemia—the point at which ischemic tissues lose the capacity to recover—is therefore a major concern, as lack of blood flow to tissues rapidly leads to tissue deoxygenation and necrosis. If left undetected or unaddressed, a potentially salvageable limb may require more extensive debridement or, more commonly, amputation. Predicting wound outcome during the initial management of blast wounds remains a significant challenge, as wounds continue to "evolve" during the debridement process and our ability to assess wound viability remains subjectively based. Better means of identifying critical ischemia are needed. We developed a swine limb ischemia model in which two imaging modalities were combined to produce an objective and quantitative assessment of wound perfusion and tissue viability. By using 3 Charge-Coupled Device (3CCD) and Infrared (IR) cameras, both surface tissue oxygenation as well as overall limb perfusion could be depicted. We observed a change in mean 3CCD and IR values at peak ischemia and during reperfusion correlate well with clinically observed indicators for limb function and vitality. After correcting for baseline mean R-B values, the 3CCD values correlate with surface tissue oxygenation and the IR values with changes in perfusion. This study aims to not only increase fundamental understanding of the processes involved with limb ischemia and reperfusion, but also to develop tools to monitor overall limb perfusion and tissue oxygenation in a clinical setting. A rapid and objective diagnostic for extent of ischemic damage and overall limb viability could provide surgeons with a more accurate indication of tissue viability. This may

  17. Quantitative, Noninvasive Imaging of DNA Damage in Vivo of Prostate Cancer Therapy by Transurethral Photoacoustic (TUPA) Imaging

    Science.gov (United States)

    2014-10-01

    Photoacoustic (TUPA) Imaging PRINCIPAL INVESTIGATOR: Liangzhong Xiang CONTRACTING ORGANIZATION: The Leland Stanford Junior University Stanford, CA...NUMBER Prostate Cancer Therapy by Transurethral Photoacoustic Imaging 5b. GRANT NUMBER W81XWH-13-1-0481 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S... Photoacoustic (TUPA) Imaging, which utilizing a small catheter into the urethra enabling imaging molecular marker of DNA Damage during prostate radiation

  18. Noninvasive two-photon imaging reveals retinyl ester storage structures in the eye.

    Science.gov (United States)

    Imanishi, Yoshikazu; Batten, Matthew L; Piston, David W; Baehr, Wolfgang; Palczewski, Krzysztof

    2004-02-01

    Visual sensation in vertebrates is triggered when light strikes retinal photoreceptor cells causing photoisomerization of the rhodopsin chromophore 11-cis-retinal to all-trans-retinal. The regeneration of preillumination conditions of the photoreceptor cells requires formation of 11-cis-retinal in the adjacent retinal pigment epithelium (RPE). Using the intrinsic fluorescence of all-trans-retinyl esters, noninvasive two-photon microscopy revealed previously uncharacterized structures (6.9 +/- 1.1 microm in length and 0.8 +/- 0.2 microm in diameter) distinct from other cellular organelles, termed the retinyl ester storage particles (RESTs), or retinosomes. These structures form autonomous all-trans-retinyl ester-rich intracellular compartments distinct from other organelles and colocalize with adipose differentiation-related protein. As demonstrated by in vivo experiments using wild-type mice, the RESTs participate in 11-cis-retinal formation. RESTs accumulate in Rpe65-/- mice incapable of carrying out the enzymatic isomerization, and correspondingly, are absent in the eyes of Lrat-/- mice deficient in retinyl ester synthesis. These results indicate that RESTs located close to the RPE plasma membrane are essential components in 11-cis-retinal production.

  19. Future non-invasive imaging to detect vascular plaque instability and subclinical non-obstructive atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    Arnon Blum; Menachem Nahir

    2013-01-01

    Atherosclerosis underlies the major causes of death in the Western World. Our main goal is to detect early changes of atherosclerosis and to identify subjects at highest cardiovascular risk that may aid in the development of prevention approaches and better management that will decrease cardiovascular morbidity and mortality. The new methods that are of interest include the advanced vascular ultrasound methods, the infra red and near infra red imaging techniques, the EndoPat device that reflects peripheral arterial tone, the electron beam computed tomography, the magnetic resonance imaging, and the molecular imaging techniques. In this review we will focus on the future of advanced imaging techniques that are being developed to detect early (pre-clinical) development of atherosclerosis.

  20. Noninvasive myocardial strain measurement by speckle tracking echocardiography: validation against sonomicrometry and tagged magnetic resonance imaging

    National Research Council Canada - National Science Library

    Amundsen, Brage H; Helle-Valle, Thomas; Edvardsen, Thor; Torp, Hans; Crosby, Jonas; Lyseggen, Erik; Støylen, Asbjørn; Ihlen, Halfdan; Lima, João A C; Smiseth, Otto A; Slørdahl, Stig A

    2006-01-01

    The aim of this study was to validate speckle tracking echocardiography (STE) as a method for angle-independent measurement of regional myocardial strain, using sonomicrometry and magnetic resonance imaging (MRI...

  1. Non-invasive Florentine Renaissance Panel Painting Replica Structures Investigation by Using Terahertz Time-Domain Imaging (THz-TDI) Technique

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Picollo, Marcello; Cucci, Costanza

    2016-01-01

    The potentials of the Terahertz Time-Domain Imaging (THz-TDI) technique for a non-invasive inspection of panel paintings have been considered in detail. The THz-TD data acquired on a replica of a panel painting made in imitation of Italian Renaissance panel paintings were processed in order to pr...

  2. Detection of Melanoma Metastases in Resected Human Lymph Nodes by Noninvasive Multispectral Photoacoustic Imaging

    Directory of Open Access Journals (Sweden)

    Gerrit Cornelis Langhout

    2014-01-01

    Full Text Available Objective. Sentinel node biopsy in patients with cutaneous melanoma improves staging, provides prognostic information, and leads to an increased survival in node-positive patients. However, frozen section analysis of the sentinel node is not reliable and definitive histopathology evaluation requires days, preventing intraoperative decision-making and immediate therapy. Photoacoustic imaging can evaluate intact lymph nodes, but specificity can be hampered by other absorbers such as hemoglobin. Near infrared multispectral photoacoustic imaging is a new approach that has the potential to selectively detect melanin. The purpose of the present study is to examine the potential of multispectral photoacoustic imaging to identify melanoma metastasis in human lymph nodes. Methods. Three metastatic and nine benign lymph nodes from eight melanoma patients were scanned ex vivo using a Vevo LAZR© multispectral photoacoustic imager and were spectrally analyzed per pixel. The results were compared to histopathology as gold standard. Results. The nodal volume could be scanned within 20 minutes. An unmixing procedure was proposed to identify melanoma metastases with multispectral photoacoustic imaging. Ultrasound overlay enabled anatomical correlation. The penetration depth of the photoacoustic signal was up to 2 cm. Conclusion. Multispectral three-dimensional photoacoustic imaging allowed for selective identification of melanoma metastases in human lymph nodes.

  3. Detection of melanoma metastases in resected human lymph nodes by noninvasive multispectral photoacoustic imaging.

    Science.gov (United States)

    Langhout, Gerrit Cornelis; Grootendorst, Diederik Johannes; Nieweg, Omgo Edo; Wouters, Michel Wilhelmus Jacobus Maria; van der Hage, Jos Alexander; Jose, Jithin; van Boven, Hester; Steenbergen, Wiendelt; Manohar, Srirang; Ruers, Theodoor Jacques Marie

    2014-01-01

    Objective. Sentinel node biopsy in patients with cutaneous melanoma improves staging, provides prognostic information, and leads to an increased survival in node-positive patients. However, frozen section analysis of the sentinel node is not reliable and definitive histopathology evaluation requires days, preventing intraoperative decision-making and immediate therapy. Photoacoustic imaging can evaluate intact lymph nodes, but specificity can be hampered by other absorbers such as hemoglobin. Near infrared multispectral photoacoustic imaging is a new approach that has the potential to selectively detect melanin. The purpose of the present study is to examine the potential of multispectral photoacoustic imaging to identify melanoma metastasis in human lymph nodes. Methods. Three metastatic and nine benign lymph nodes from eight melanoma patients were scanned ex vivo using a Vevo LAZR(©) multispectral photoacoustic imager and were spectrally analyzed per pixel. The results were compared to histopathology as gold standard. Results. The nodal volume could be scanned within 20 minutes. An unmixing procedure was proposed to identify melanoma metastases with multispectral photoacoustic imaging. Ultrasound overlay enabled anatomical correlation. The penetration depth of the photoacoustic signal was up to 2 cm. Conclusion. Multispectral three-dimensional photoacoustic imaging allowed for selective identification of melanoma metastases in human lymph nodes.

  4. In vivo photothermal optical coherence tomography for non-invasive imaging of endogenous absorption agents.

    Science.gov (United States)

    Makita, Shuichi; Yasuno, Yoshiaki

    2015-05-01

    In vivo photothermal optical coherence tomography (OCT) is demonstrated for cross-sectional imaging of endogenous absorption agents. In order to compromise the sensitivity, imaging speed, and sample motion immunity, a new photothermal detection scheme and phase processing method are developed. Phase-resolved swept-source OCT and fiber-pigtailed laser diode (providing excitation at 406 nm) are combined to construct a high-sensitivity photothermal OCT system. OCT probe and excitation beam coaxially illuminate and are focused on tissues. The photothermal excitation and detection procedure is designed to obtain high efficiency of photothermal effect measurement. The principle and method of depth-resolved cross-sectional imaging of absorption agents with photothermal OCT has been derived. The phase-resolved thermal expansion detection algorithm without motion artifact enables in vivo detection of photothermal effect. Phantom imaging with a blood phantom and in vivo human skin imaging are conducted. A phantom with guinea-pig blood as absorber has been scanned by the photothermal OCT system to prove the concept of cross-sectional absorption agent imaging. An in vivo human skin measurement is also performed with endogenous absorption agents.

  5. Non-invasive, near-field terahertz imaging of hidden objects using a single pixel detector

    CERN Document Server

    Stantchev, R I; Hornett, S M; Hobson, P A; Gibson, G M; Padgett, M J; Hendry, E

    2015-01-01

    Terahertz (THz) imaging has the ability to see through otherwise opaque materials. However, due to the long wavelengths of THz radiation ({\\lambda}=300{\\mu}m at 1THz), far-field THz imaging techniques are heavily outperformed by optical imaging in regards to the obtained resolution. In this work we demonstrate near-field THz imaging with a single-pixel detector. We project a time-varying optical mask onto a silicon wafer which is used to spatially modulate a pulse of THz radiation. The far-field transmission corresponding to each mask is recorded by a single element detector and this data is used to reconstruct the image of an object placed on the far side of the silicon wafer. We demonstrate a proof of principal application where we image a printed circuit board on the underside of a 115{\\mu}m thick silicon wafer with ~100{\\mu}m ({\\lambda}/4) resolution. With subwavelength resolution and the inherent sensitivity to local conductivity provided by the THz probe frequencies, we show that it is possible to detec...

  6. Towards a Noninvasive Intracranial Tumor Irradiation Using 3D Optical Imaging and Multimodal Data Registration

    Science.gov (United States)

    Posada, R.; Daul, Ch.; Wolf, D.; Aletti, P.

    2007-01-01

    Conformal radiotherapy (CRT) results in high-precision tumor volume irradiation. In fractioned radiotherapy (FRT), lesions are irradiated in several sessions so that healthy neighbouring tissues are better preserved than when treatment is carried out in one fraction. In the case of intracranial tumors, classical methods of patient positioning in the irradiation machine coordinate system are invasive and only allow for CRT in one irradiation session. This contribution presents a noninvasive positioning method representing a first step towards the combination of CRT and FRT. The 3D data used for the positioning is point clouds spread over the patient's head (CT-data usually acquired during treatment) and points distributed over the patient's face which are acquired with a structured light sensor fixed in the therapy room. The geometrical transformation linking the coordinate systems of the diagnosis device (CT-modality) and the 3D sensor of the therapy room (visible light modality) is obtained by registering the surfaces represented by the two 3D point sets. The geometrical relationship between the coordinate systems of the 3D sensor and the irradiation machine is given by a calibration of the sensor position in the therapy room. The global transformation, computed with the two previous transformations, is sufficient to predict the tumor position in the irradiation machine coordinate system with only the corresponding position in the CT-coordinate system. Results obtained for a phantom show that the mean positioning error of tumors on the treatment machine isocentre is 0.4 mm. Tests performed with human data proved that the registration algorithm is accurate (0.1 mm mean distance between homologous points) and robust even for facial expression changes. PMID:18364992

  7. A biocompatible in vivo ligation reaction and its application for noninvasive bioluminescent imaging of protease activity in living mice.

    Science.gov (United States)

    Godinat, Aurélien; Park, Hyo Min; Miller, Stephen C; Cheng, Ke; Hanahan, Douglas; Sanman, Laura E; Bogyo, Matthew; Yu, Allen; Nikitin, Gennady F; Stahl, Andreas; Dubikovskaya, Elena A

    2013-05-17

    The discovery of biocompatible reactions had a tremendous impact on chemical biology, allowing the study of numerous biological processes directly in complex systems. However, despite the fact that multiple biocompatible reactions have been developed in the past decade, very few work well in living mice. Here we report that D-cysteine and 2-cyanobenzothiazoles can selectively react with each other in vivo to generate a luciferin substrate for firefly luciferase. The success of this "split luciferin" ligation reaction has important implications for both in vivo imaging and biocompatible labeling strategies. First, the production of a luciferin substrate can be visualized in a live mouse by bioluminescence imaging (BLI) and furthermore allows interrogation of targeted tissues using a "caged" luciferin approach. We therefore applied this reaction to the real-time noninvasive imaging of apoptosis associated with caspase 3/7. Caspase-dependent release of free D-cysteine from the caspase 3/7 peptide substrate Asp-Glu-Val-Asp-D-Cys (DEVD-(D-Cys)) allowed selective reaction with 6-amino-2-cyanobenzothiazole (NH(2)-CBT) in vivo to form 6-amino-D-luciferin with subsequent light emission from luciferase. Importantly, this strategy was found to be superior to the commercially available DEVD-aminoluciferin substrate for imaging of caspase 3/7 activity. Moreover, the split luciferin approach enables the modular construction of bioluminogenic sensors, where either or both reaction partners could be caged to report on multiple biological events. Lastly, the luciferin ligation reaction is 3 orders of magnitude faster than Staudinger ligation, suggesting further applications for both bioluminescence and specific molecular targeting in vivo.

  8. Noninvasive quantification of in vitro osteoblastic differentiation in 3D engineered tissue constructs using spectral ultrasound imaging.

    Science.gov (United States)

    Gudur, Madhu Sudhan Reddy; Rao, Rameshwar R; Peterson, Alexis W; Caldwell, David J; Stegemann, Jan P; Deng, Cheri X

    2014-01-01

    Non-destructive monitoring of engineered tissues is needed for translation of these products from the lab to the clinic. In this study, non-invasive, high resolution spectral ultrasound imaging (SUSI) was used to monitor the differentiation of MC3T3 pre-osteoblasts seeded within collagen hydrogels. SUSI was used to measure the diameter, concentration and acoustic attenuation of scatterers within such constructs cultured in either control or osteogenic medium over 21 days. Conventional biochemical assays were used on parallel samples to determine DNA content and calcium deposition. Construct volume and morphology were accurately imaged using ultrasound. Cell diameter was estimated to be approximately 12.5-15.5 µm using SUSI, which corresponded well to measurements of fluorescently stained cells. The total number of cells per construct assessed by quantitation of DNA content decreased from 5.6±2.4×10(4) at day 1 to 0.9±0.2×10(4) at day 21. SUSI estimation of the equivalent number of acoustic scatters showed a similar decreasing trend, except at day 21 in the osteogenic samples, which showed a marked increase in both scatterer number and acoustic impedance, suggestive of mineral deposition by the differentiating MC3T3 cells. Estimation of calcium content by SUSI was 41.7±11.4 µg/ml, which agreed well with the biochemical measurement of 38.7±16.7 µg/ml. Color coded maps of parameter values were overlaid on B-mode images to show spatiotemporal changes in cell diameter and calcium deposition. This study demonstrates the use of non-destructive ultrasound imaging to provide quantitative information on the number and differentiated state of cells embedded within 3D engineered constructs, and therefore presents a valuable tool for longitudinal monitoring of engineered tissue development.

  9. 5th German cardiodiagnostic meeting 2013 with the 6th Leipzig Symposium on non-invasive cardiovascular imaging. Challenges and limit of the non-invasive cardiac imaging; 5. Deutsche Kardiodiagnostik-Tage 2013 mit 6. Leipziger Symposium Nichtinvasive Kardiovaskulaere Bildgebung. Herausforderungen und Grenzen der nicht-invasiven kardialen Bildgebung

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-04-01

    The proceedings on the German cardiodiagnostic meeting 2013 together with the 6th Leipzig Symposium on non-invasive cardiovascular imaging include abstracts concerning the following topics: Imaging in the rhythmology; adults with congenital cardiac defects; cardiac myopathies - myocarditis; cardiac valves (before and after transcutaneous valve replacement); coronary heart diseases; technical developments.

  10. MRI-Derived Cellularity Index as a Potential Noninvasive Imaging Biomarker of Prostate Cancer

    Science.gov (United States)

    2014-10-01

    AWARD NUMBER: W81XWH-13-1-0391 TITLE: MRI -Derived Cellularity Index as a Potential...2. REPORT TYPE Annual report 3. DATES COVERED 15 Sep 2013 - 14 Sep 2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER MRI ...NOTES 14. ABSTRACT Standard magnetic resonance imaging ( MRI ) of the prostate lacks sensitivity in the diagnosis and staging of prostate cancer (PCa

  11. Towards non-invasive diagnostic imaging of early-stage Alzheimer's disease

    Science.gov (United States)

    Viola, Kirsten L.; Sbarboro, James; Sureka, Ruchi; de, Mrinmoy; Bicca, Maíra A.; Wang, Jane; Vasavada, Shaleen; Satpathy, Sreyesh; Wu, Summer; Joshi, Hrushikesh; Velasco, Pauline T.; Macrenaris, Keith; Waters, E. Alex; Lu, Chang; Phan, Joseph; Lacor, Pascale; Prasad, Pottumarthi; Dravid, Vinayak P.; Klein, William L.

    2015-01-01

    One way to image the molecular pathology in Alzheimer's disease is by positron emission tomography using probes that target amyloid fibrils. However, these fibrils are not closely linked to the development of the disease. It is now thought that early-stage biomarkers that instigate memory loss are composed of Aβ oligomers. Here, we report a sensitive molecular magnetic resonance imaging contrast probe that is specific for Aβ oligomers. We attach oligomer-specific antibodies onto magnetic nanostructures and show that the complex is stable and binds to Aβ oligomers on cells and brain tissues to give a magnetic resonance imaging signal. When intranasally administered to an Alzheimer's disease mouse model, the probe readily reached hippocampal Aβ oligomers. In isolated samples of human brain tissue, we observed a magnetic resonance imaging signal that distinguished Alzheimer's disease from controls. Such nanostructures that target neurotoxic Aβ oligomers are potentially useful for evaluating the efficacy of new drugs and ultimately for early-stage Alzheimer's disease diagnosis and disease management.

  12. Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy.

    Science.gov (United States)

    van Manen, Henk-Jan; Lenferink, Aufried; Otto, Cees

    2008-12-15

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C-D stretching vibrational bands in these amino acids are observed in the 2100-2300 cm(-1) spectral region that is devoid of vibrational contributions from other, nondeuterated intracellular constituents. We found that incubation with deuterated amino acids for 8 h in cell culture already led to clearly detectable isotope-related signals in Raman spectra of HeLa cells. As expected, the level of isotope incorporation into proteins increased with incubation time, reaching 55% for deuterated phenylalanine after 28 h. Raman spectral imaging of HeLa cells incubated with deuterium-labeled amino acids showed similar spatial distributions for both isotope-labeled and unlabeled proteins, as evidenced by Raman ratio imaging. The SILAC-Raman methodology presented here combines the strengths of stable isotopic labeling of cells with the nondestructive and quantitative nature of Raman chemical imaging and is likely to become a powerful tool in both cell biology applications and research on tissues or whole organisms.

  13. Noninvasive Imaging of Protein Metabolic Labeling in Single Human Cells Using Stable Isotopes and Raman Microscopy

    NARCIS (Netherlands)

    Manen, van Henk-Jan; Lenferink, Aufried; Otto, Cees

    2008-01-01

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D stret

  14. Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy

    NARCIS (Netherlands)

    van Manen, H.J.; Lenferink, Aufrid T.M.; Otto, Cornelis

    2008-01-01

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D

  15. Non-invasive nano-imaging of ion implanted and activated copper in silicon

    Science.gov (United States)

    Ballout, Fouad; Samson, Jean-Sébastien; Schmidt, Diedrich A.; Bründermann, Erik; Mathis, Yves-Laurent; Gasharova, Biliana; Dirk Wieck, Andreas; Havenith, Martina

    2011-07-01

    Using vibrational imaging techniques including Fourier-transform infrared (FTIR) synchrotron microscopy, Raman microscopy, and scattering scanning near-field infrared microcscopy (s-SNIM), we mapped a sample of phosphor and copper ions implanted in a high-purity silicon wafer. While Raman microscopy monitors the structural disorder within the implantation fields, the aforementionedinfrared techniques provide a detailed picture of the distribution of the free carriers. On a large scale (tens of micrometers), we visualized the channeling effects of phosphor dopants in silicon using FTIR microscopy. In comparison, using s-SNIM we were able to image, on a nanometer scale, local variations of the dielectric properties of the silicon substrate due to the activation of copper dopants.

  16. [Successful surgical management of aortico-left ventricular tunnel using modern noninvasive diagnostic imaging methods].

    Science.gov (United States)

    Hartyánszky, István; Katona, Márta; Kádár, Krisztina; Apor, Asztrid; Varga, Sándor; Simon, Judit; Tóth, Attila; Karácsony, Tünde; Bogáts, Gábor

    2015-07-12

    Aortico-left ventricular tunnel is a rare congenital cardiac defect, which bypasses the aortic valve via the paravalvar connection from the aorta to the left ventricle. The authors present the case of a 14-year-old boy with aortico-left ventricular tunnel in whom the aortic orifice arose from the right aortic sinus and was closed by a pericardial patch. The diagnosis was confirmed by combined two-dimensional and real time three-dimensional echocardiogram and magnetic resonance imaging. This is the first case, in which these complex diagnostic imaging methods have been used in the pre- and postoperative management of this defect. Optimally the new transthoratic three-dimensional echocardiography would be needed to define the anatomy and functional consequences of the aortico-left ventricular tunnel and in the postoperative follow-up.

  17. MRI-Derived Cellularity Index as a Potential Noninvasive Imaging Biomarker of Prostate Cancer

    Science.gov (United States)

    2016-12-01

    Research. clincancerres.aacrjournals.org Downloaded from targeted treatments or procedures, such as MRI-guided fusion biopsies . With this novel technology ...these techniques increase our ability to detect extraprostatic extension, improve accuracy of targeted biopsies and we show that our quantitative...2015) 3) RSI imaging has also been implemented as part of the work flow for defining tumor regions of interest for targeted biopsy using Dynacad

  18. High-definition optical coherence tomography imaging for noninvasive examination of heritage works.

    Science.gov (United States)

    Zaki, Farzana; Hou, Isabella; Cooper, Denver; Patel, Divya; Yang, Yi; Liu, Xuan

    2016-12-20

    Cultural heritage works, such as ancient murals and historical paintings, are examined routinely for the purpose of conservation. Previous works have applied optical coherence tomography (OCT), which is a three-dimensional (3D) microscopic imaging modality in the field of heritage works conservation. The data acquired by OCT provides both 3D surface information of the object and structure information underneath the surface. Therefore, cross-sectional information on the object can be utilized to study layer structure of the painting and brush stroke techniques used by the artist. However, as demonstrated in previous studies, OCT has limited capability in high-definition (HD) examination of paintings or murals that are in macroscopic scale. HD examination of heritage works needs to scan large areas and process huge amounts of data, while OCT imaging has a limited field of view and processing power. To further advance the application of OCT in the conservation of heritage works, we demonstrate what we believe is a novel high-speed, large field-of-view (FOV) OCT imaging platform. Our results suggest that this OCT platform has the potential to become a nondestructive alternative for the analysis and conservation of paintings and murals.

  19. Dynamic noninvasive monitoring of renal function in vivo by fluorescence lifetime imaging

    Science.gov (United States)

    Goiffon, Reece J.; Akers, Walter J.; Berezin, Mikhail Y.; Lee, Hyeran; Achilefu, Samuel

    2009-03-01

    Kidneys normally filter the blood of excess salts and metabolic products, such as urea, while retaining plasma proteins. In diseases such as multiple myeloma and diabetes mellitus, the renal function is compromised and protein escapes into the urine. In this study, we present the use of fluorescence lifetime imaging (FLI) to image excess serum protein in urine (proteinuria). The near-infrared fluorescent dye LS-288 has distinct lifetimes when bound to protein versus free in solution, providing contrast between the protein-rich viscera and the mostly protein-free bladder. FLI with LS-288 in mice revealed that fluorescence lifetime (FLT) differences in the bladder relative to surrounding tissues was due to the fractional contributions of the bound and unbound dye molecules. The FLT of LS-288 decreased in the case of proteinuria while fluorescence intensity was unchanged. The results show that FLI can be useful for the dynamic imaging of protein-losing nephropathy due to diabetes mellitus and other renal diseases and suggest the potential use of the FLI to distinguish tumors from fluid-filled cysts in the body.

  20. Static laser speckle contrast analysis for noninvasive burn diagnosis using a camera-phone imager.

    Science.gov (United States)

    Ragol, Sigal; Remer, Itay; Shoham, Yaron; Hazan, Sivan; Willenz, Udi; Sinelnikov, Igor; Dronov, Vladimir; Rosenberg, Lior; Bilenca, Alberto

    2015-08-01

    Laser speckle contrast analysis (LASCA) is an established optical technique for accurate widefield visualization of relative blood perfusion when no or minimal scattering from static tissue elements is present, as demonstrated, for example, in LASCA imaging of the exposed cortex. However, when LASCA is applied to diagnosis of burn wounds, light is backscattered from both moving blood and static burn scatterers, and thus the spatial speckle contrast includes both perfusion and nonperfusion components and cannot be straightforwardly associated to blood flow. We extract from speckle contrast images of burn wounds the nonperfusion (static) component and discover that it conveys useful information on the ratio of static-to-dynamic scattering composition of the wound, enabling identification of burns of different depth in a porcine model in vivo within the first 48 h postburn. Our findings suggest that relative changes in the static-to-dynamic scattering composition of burns can dominate relative changes in blood flow for burns of different severity. Unlike conventional LASCA systems that employ scientific or industrial-grade cameras, our LASCA system is realized here using a camera phone, showing the potential to enable LASCA-based burn diagnosis with a simple imager.

  1. Three-dimensional ventricular activation imaging by means of equivalent current source modeling and estimation.

    Science.gov (United States)

    Liu, Z; Liu, C; He, B

    2006-01-01

    This paper presents a novel electrocardiographic inverse approach for imaging the 3-D ventricular activation sequence based on the modeling and estimation of the equivalent current density throughout the entire myocardial volume. The spatio-temporal coherence of the ventricular excitation process is utilized to derive the activation time from the estimated time course of the equivalent current density. At each time instant during the period of ventricular activation, the distributed equivalent current density is noninvasively estimated from body surface potential maps (BSPM) using a weighted minimum norm approach with a spatio-temporal regularization strategy based on the singular value decomposition of the BSPMs. The activation time at any given location within the ventricular myocardium is determined as the time point with the maximum local current density estimate. Computer simulation has been performed to evaluate the capability of this approach to image the 3-D ventricular activation sequence initiated from a single pacing site in a physiologically realistic cellular automaton heart model. The simulation results demonstrate that the simulated "true" activation sequence can be accurately reconstructed with an average correlation coefficient of 0.90, relative error of 0.19, and the origin of ventricular excitation can be localized with an average localization error of 5.5 mm for 12 different pacing sites distributed throughout the ventricles.

  2. Non-invasive imaging of acute renal allograft rejection in rats using small animal F-FDG-PET.

    Directory of Open Access Journals (Sweden)

    Stefan Reuter

    Full Text Available BACKGROUND: At present, renal grafts are the most common solid organ transplants world-wide. Given the importance of renal transplantation and the limitation of available donor kidneys, detailed analysis of factors that affect transplant survival are important. Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection (AR is still a major risk for graft survival. Nowadays, AR can only be definitively by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Most important, they can not be performed in patients taking anticoagulant drugs. METHODOLOGY/PRINCIPAL FINDINGS: We present a non-invasive, entirely image-based method to assess AR in an allogeneic rat renal transplantation model using small animal positron emission tomography (PET and (18F-fluorodeoxyglucose (FDG. 3 h after i.v. injection of 30 MBq FDG into adult uni-nephrectomized, allogeneically transplanted rats, tissue radioactivity of renal parenchyma was assessed in vivo by a small animal PET-scanner (post operative day (POD 1,2,4, and 7 and post mortem dissection. The mean radioactivity (cps/mm(3 tissue as well as the percent injected dose (%ID was compared between graft and native reference kidney. Results were confirmed by histological and autoradiographic analysis. Healthy rats, rats with acute CSA nephrotoxicity, with acute tubular necrosis, and syngeneically transplanted rats served as controls. FDG-uptake was significantly elevated only in allogeneic grafts from POD 1 on when compared to the native kidney (%ID graft POD 1: 0.54+/-0.06; POD 2: 0.58+/-0.12; POD 4: 0.81+/-0.06; POD 7: 0.77+/-0.1; CTR: 0.22+/-0.01, n = 3-28. Renal FDG-uptake in vivo correlated with the results obtained by micro-autoradiography and the degree of inflammatory infiltrates observed in histology. CONCLUSIONS/SIGNIFICANCE: We propose that graft FDG-PET imaging is a new option to non-invasively, specifically, early detect, and follow

  3. Noninvasive quantification of coronary endothelial function by SPECT imaging in children with a history of Kawasaki disease

    Energy Technology Data Exchange (ETDEWEB)

    Cicala, Silvana; Paladini, Rodolfo; Leva, Francesco de [Santobono-Pausilipon Children Medical Hospital, Division of Cardiology, Department of Paediatrics, Naples (Italy); Pellegrino, Teresa; Caprio, Maria Grazia [Institute of Diagnostic and Nuclear Development, SDN Foundation, Naples (Italy); Storto, Giovanni [IRCCS, CROB, Rionero in Vulture (Italy); Mainolfi, Ciro; Cuocolo, Alberto [Federico II University, Department of Biomorphological and Functional Sciences, Naples (Italy); National Council of Research, Institute of Biostructures and Bioimages, Naples (Italy)

    2010-12-15

    The feasibility of coronary function estimation by single photon emission computed tomography (SPECT) has been recently demonstrated. The aim of this study was to apply SPECT imaging in patients with previous Kawasaki disease (KD) to assess the coronary functional status at long-term follow-up of the acute phase of the disease. Sixteen children with a history of KD underwent {sup 99m}Tc-sestamibi imaging at rest and during the cold pressor test (CPT). Myocardial blood flow (MBF) was estimated by measuring first transit counts in the pulmonary artery and myocardial counts from SPECT images. Coronary endothelial function was expressed as the ratio of the CPT to rest MBF. Six KD patients without coronary artery lesions served as controls and ten with coronary artery aneurysms during the acute phase of the disease were separated into two groups: group 1 (n = 4) with regressed and group 2 (n = 6) with persistent aneurysm at follow-up. The estimated coronary endothelial function was higher in controls compared to patients with coronary artery aneurysms (2.5 {+-} 0.3 vs 1.7 {+-} 0.7, p < 0.05). A significant difference in coronary endothelial function among groups was found (F = 5.21, p < 0.02). Coronary endothelial function was higher in patients of group 1 than in those of group 2 (1.9 {+-} 0.6 vs 1.4 {+-} 0.7, p < 0.02). SPECT may be applied as a noninvasive method for assessing coronary vascular function in children with a history of KD, demonstrating an impaired response to the CPT, an endothelial-dependent vasodilator stimulus. These findings reinforce the concept that coronary endothelial dysfunction may represent a long-term sequela of KD. (orig.)

  4. Non-invasive Measurement of Thermal Diffusivity Using High-Intensity Focused Ultrasound and Through-Transmission Ultrasonic Imaging.

    Science.gov (United States)

    Yeshurun, Lilach; Azhari, Haim

    2016-01-01

    Thermal diffusivity at the site ablated by high-intensity focused ultrasound (HIFU) plays an important role in the final therapeutic outcome, as it influences the temperature's spatial and temporal distribution. Moreover, as tissue thermal diffusivity is different in tumors as compared with normal tissue, it could also potentially be used as a new source of imaging contrast. The aim of this study was to examine the feasibility of combining through-transmission ultrasonic imaging and HIFU to estimate thermal diffusivity non-invasively. The concept was initially evaluated using a computer simulation. Then it was experimentally tested on phantoms made of agar and ex vivo porcine fat. A computerized imaging system combined with a HIFU system was used to heat the phantoms to temperatures below 42°C to avoid irreversible damage. Through-transmission scanning provided the time-of-flight values in a region of interest during its cooling process. The time-of-flight values were consequently converted into mean values of speed of sound. Using the speed-of-sound profiles along with the developed model, we estimated the changes in temperature profiles over time. These changes in temperature profiles were then used to calculate the corresponding thermal diffusivity of the studied specimen. Thermal diffusivity for porcine fat was found to be lower by one order of magnitude than that obtained for agar (0.313×10(-7)m(2)/s vs. 4.83×10(-7)m(2)/s, respectively, p ultrasound thermal diffusivity mapping is feasible. The suggested method may particularly be suitable for breast scanning.

  5. On non-invasive 2D and 3D Chromatic White Light image sensors for age determination of latent fingerprints.

    Science.gov (United States)

    Merkel, Ronny; Gruhn, Stefan; Dittmann, Jana; Vielhauer, Claus; Bräutigam, Anja

    2012-10-10

    The feasibility of 2D-intensity and 3D-topography images from a non-invasive Chromatic White Light (CWL) sensor for the age determination of latent fingerprints is investigated. The proposed method might provide the means to solve the so far unresolved issue of determining a fingerprints age in forensics. Conducting numerous experiments for an indoor crime scene using selected surfaces, different influences on the aging of fingerprints are investigated and the resulting aging variability is determined in terms of inter-person, intra-person, inter-finger and intra-finger variation. Main influence factors are shown to be the sweat composition, temperature, humidity, wind, UV-radiation, surface type, contamination of the finger with water-containing substances, resolution and measured area size, whereas contact time, contact pressure and smearing of the print seem to be of minor importance. Such influences lead to a certain experimental variability in inter-person and intra-person variation, which is higher than the inter-finger and intra-finger variation. Comparing the aging behavior of 17 different features using 1490 time series with a total of 41,520 fingerprint images, the great potential of the CWL technique in combination with the binary pixel feature from prior work is shown. Performing three different experiments for the classification of fingerprints into the two time classes [0, 5 h] and [5, 24 h], a maximum classification performance of 79.29% (kappa=0.46) is achieved for a general case, which is further improved for special cases. The statistical significance of the two best-performing features (both binary pixel versions based on 2D-intensity images) is manually shown and a feature fusion is performed, highlighting the strong dependency of the features on each other. It is concluded that such method might be combined with additional capturing devices, such as microscopes or spectroscopes, to a very promising age estimation scheme.

  6. New imaging methods for non-invasive assessment of mechanical, structural and biochemical properties of Human Achilles tendon: a mini review

    Directory of Open Access Journals (Sweden)

    Alexandre Fouré

    2016-07-01

    Full Text Available The mechanical properties of tendon play a fundamental role to passively transmit forces from muscle to bone, withstand sudden stretches and act as a mechanical buffer allowing the muscle to work more efficiently. The use of non-invasive imaging methods for the assessment of human tendon’s mechanical, structural and biochemical properties in vivo is relatively young in sports medicine, clinical practice and basic science. Non-invasive assessment of the tendon properties may enhance the diagnosis of tendon injury and the characterization of recovery treatments. While ultrasonographic imaging is the most popular tool to assess the tendon’s structural and, indirectly, mechanical properties, ultrasonographic elastography and ultra-high field magnetic resonance imaging (UHF MRI have recently emerged as potentially powerful techniques to explore tendon tissues. This paper highlights some methodological cautions associated with conventional ultrasonography and perspectives for in vivo human Achilles tendon assessment using ultrasonographic elastography and UHF MRI.

  7. Image guided robotic surgery: Current evidence for effectiveness in urology

    Directory of Open Access Journals (Sweden)

    Anum Pervez

    2014-12-01

    Full Text Available Objectives: Discussion of the evolution of image guided surgery (IGS and its fundamental components and current evidence for effectiveness of IGS in clinical urology. Methods: Literature search for image-guided robotic urology. Results: Current literature in image-guided robotic urology with its use in robot assisted radical prostatectomy and robot assisted partial nephrectomy are shown. Conclusions: Image guided surgery can be a useful aid to improve visualisation of anatomy and subsurface structures during minimally invasive surgery. Soft-tissue deformation makes it difficult to implement IGS in urology but current studies have shown an attempt to address this issue. The feasibility of IGS requires randomised control trials assessing in particular its accuracy and affect on clinical outcome.

  8. Noninvasive 2-dimensional monitoring of strain in the detrusor muscle in patients with lower urinary tract symptoms using ultrasound strain imaging

    NARCIS (Netherlands)

    Idzenga, T.; Farag, F.; Heesakkers, J.P.F.A.; Feitz, W.; Korte, C.L. de

    2013-01-01

    PURPOSE: Pressure flow studies and filling cystometry are currently the standard diagnostic urodynamic tests for lower urinary tract symptoms. A noninvasive ultrasound based method for 2-dimensional monitoring of deformation (or strain) in the detrusor muscle may provide insight into detrusor muscle

  9. Thermal impact of near-infrared laser in advanced noninvasive optical brain imaging.

    Science.gov (United States)

    Nourhashemi, Mina; Mahmoudzadeh, Mahdi; Wallois, Fabrice

    2016-01-01

    The propagation of laser light in human tissues is an important issue in functional optical imaging. We modeled the thermal effect of different laser powers with various spot sizes and different head tissue characteristics on neonatal and adult quasirealistic head models. The photothermal effect of near-infrared laser (800 nm) was investigated by numerical simulation using finite-element analysis. Our results demonstrate that the maximum temperature increase on the brain for laser irradiance between 0.127 (1 mW) and [Formula: see text] (100 mW) at a 1 mm spot size, ranged from 0.0025°C to 0.26°C and from 0.03°C to 2.85°C at depths of 15.9 and 4.9 mm in the adult and neonatal brain, respectively. Due to the shorter distance of the head layers from the neonatal head surface, the maximum temperature increase was higher in the neonatal brain than in the adult brain. Our results also show that, at constant power, spot size changes had a lesser heating effect on deeper tissues. While the constraints for safe laser irradiation to the brain are dictated by skin safety, these results can be useful to optimize laser parameters for a variety of laser applications in the brain. Moreover, combining simulation and adequate in vitro experiments could help to develop more effective optical imaging to avoid possible tissue damage.

  10. Near-Infrared Fluorescence Imaging for Noninvasive Trafficking of Scaffold Degradation

    OpenAIRE

    Soon Hee Kim; Jeong Heon Lee; Hoon Hyun; Yoshitomo Ashitate; GwangLi Park; Kyle Robichaud; Elaine Lunsford; Sang Jin Lee; Gilson Khang; Hak Soo Choi

    2013-01-01

    Biodegradable scaffolds could revolutionize tissue engineering and regenerative medicine; however, in vivo matrix degradation and tissue ingrowth processes are not fully understood. Currently a large number of samples and animals are required to track biodegradation of implanted scaffolds, and such nonconsecutive single-time-point information from various batches result in inaccurate conclusions. To overcome this limitation, we developed functional biodegradable scaffolds by employing invisib...

  11. Cardiac magnetic source imaging based on current multipole model

    Institute of Scientific and Technical Information of China (English)

    Tang Fa-Kuan; Wang Qian; Hua Ning; Lu Hong; Tang Xue-Zheng; Ma Ping

    2011-01-01

    It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution.Then the minimum-norm least-squares (MNLS) method, the optimal weighted pseuDOInverse method (OWPIM), and the optimal constrained linear inverse method (OCLIM) are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides,two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

  12. Non-invasive perfusion imaging by modified STAR using asymmetric inversion slabs (ASTAR)

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tokunori [Toshiba Nasu Works, Otawara, Tochigi (Japan)

    2000-12-01

    Arterial spin labeling (ASL) such as STAR, EPISTAR, and FAIR have been used as imaging techniques of tissue perfusion and blood vessels (in MRA). We have developed 'ASTAR', a modified version of STAR by using asymmetric inversion slabs. ASTAR solves the problems of suppression of venous inflow and subtraction error of stationary tissue signal caused by the imbalance of signal variations. The signal variations are dependent on MT effects. In order to avoid overlapping the control slab to the tissue (including large veins), the control and tag slabs are arranged asymmetrically to preserve the same offset of modulation frequency. We evaluated both the subtraction error caused by the MT effects, and the imperfection of an IR slab using a stationary phantom. We then measured the vessel signal on the brain of a volunteer, using the above methods. Two indexes were used for the evaluation: ASL signal to control signal ratio (ASLR [%]=100*deltaS/S{sub cont}) and ASL signal to noise ratio (ASLNR=delatS/Noise) where deltaS=|S{sub cont}-S{sub tag}|. Phantom study: each ASLR and ASLNR between ASTAR and EPISTAR was comparable and showed a decrease in noise signal level. This means that the ASL signal from the stationary tissue with an imbalance in MT effects and the imperfection in inversion slab profiles were cancelled out almost perfectly. When calculating CBF, ASLR for zero perfusion stationary tissue should be below 0.1%. We were able to satisfy this requirement in our ASTAR experiment. ASLR and ASLNR in FAIR were 40% larger than in EPISTAR and ASTAR. Volunteer brain study: compared with each ASL image, the MT effects were cancelled out in EPISTAR and ASTAR. Veins (sagittal sinus etc) disappeared in STAR and ASTAR, but were visible in EPISTAR and FAIR. Perfusion signals were similar in ASTAR and EPISTAR, indicating that both cancellation of MT effects and venous inflow from the opposite side of the tag were suppressed in ASTAR. In conclusion, ASTAR is a practical

  13. Imaging of lumbar degenerative disk disease: history and current state

    Energy Technology Data Exchange (ETDEWEB)

    Emch, Todd M. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neuroradiology L-10, Cleveland, OH (United States); Modic, Michael T. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neurological Institute T-13, Cleveland, OH (United States)

    2011-09-15

    One of the most common indications for performing magnetic resonance (MR) imaging of the lumbar spine is the symptom complex thought to originate as a result of degenerative disk disease. MR imaging, which has emerged as perhaps the modality of choice for imaging degenerative disk disease, can readily demonstrate disk pathology, degenerative endplate changes, facet and ligamentous hypertrophic changes, and the sequelae of instability. Its role in terms of predicting natural history of low back pain, identifying causality, or offering prognostic information is unclear. As available modalities for imaging the spine have progressed from radiography, myelography, and computed tomography to MR imaging, there have also been advances in spine surgery for degenerative disk disease. These advances are described in a temporal context for historical purposes with a focus on MR imaging's history and current state. (orig.)

  14. Noninvasive imaging of three dimensional micro and nanostructures by topological methods

    CERN Document Server

    Carpio, A; Rapun, M L; Selgas, V

    2016-01-01

    We present topological derivative and energy based procedures for the imaging of micro and nanostructures using one beam of visible light of a single wavelength. Objects with diameters as small as 10 nm can be located, and their position tracked with nanometer precision. Multiple objects distributed either on planes perpendicular to the incidence direction or along axial lines in the incidence direction are distinguishable. More precisely, the shape and size of plane sections perpendicular to the incidence direction can be clearly determined, even for asymmetric and non-convex scatterers. Axial resolution improves as the size of the objects decreases. Initial reconstructions may proceed by glueing together 2D horizontal slices between axial peaks or by locating objects at 3D peaks of topological energies, depending on the effective wavenumber. Below a threshold size, topological derivative based iterative schemes improve initial predictions of the location, size and shape of objects by postprocessing fixed me...

  15. Noninvasive MRI-SERS Imaging in Living Mice Using an Innately Bimodal Nanomaterial

    Science.gov (United States)

    Yigit, Mehmet V.; Zhu, Leyun; Ifediba, Marytheresa A.; Zhang, Yong; Carr, Kevin; Moore, Anna; Medarova, Zdravka

    2011-01-01

    We report a novel nanomaterial (AuMN-DTTC) that can be used as a bimodal contrast agent for in vivo magnetic resonance imaging (MRI) and Raman spectroscopy. The probe consists of MRI-active superparamagnetic iron oxide nanoparticles, stably complexed with gold nanostructures. The gold component serves as a substrate for a Raman active dye molecule to generate a surface-enhanced Raman scattering (SERS) effect. The synthesized probe produces T2 weighted contrast and can be used as a SERS active material both in silico (in aqueous solution) and in vivo. A quantitative assessment of T2 relaxation times was obtained using multiecho MRI analysis. The T2 relaxation times of AuMN-DTTC and MN (dextran-coated iron oxide nanoparticles) were 29.23 + 1.45, and 31.58 + 1.7 msec, respectively. The SERS signature of AuMN-DTTC revealed peaks at 508, 629, 782, 844, 1080, 1108, 1135, and 1242 cm−1. Intramuscular administration of the probe resulted in a decrease of the T2 relaxation time of muscle from 33.4 + 2.5 msec to 20.3 + 2.2. SERS peaks were observed at 508, 629, 782, 844, 1080, 1108, 1135, and 1242 cm−1, consistent with the in silico results. Our studies illustrate for the first time the design and in vivo application of a contrast agent, whose component modalities include MRI and SERS. The value of this agent lies in its innately bimodal nature and its application in vivo for molecular imaging applications. PMID:21194236

  16. Noninvasive staging of lung cancer. Indications and limitations of gallium-67 citrate imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bekerman, C.; Caride, V.J.; Hoffer, P.B.; Boles, C.A. (Univ. of Illinois, Chicago (USA))

    1990-05-01

    The results of evaluation of the hila and mediastinum with 67Ga scans are contradictory, as are the recommendations by different investigators on the use of 67Ga scintigraphy in the clinical evaluation of patients with primary lung carcinoma. Nevertheless, the economy and logistic simplicity of evaluating local and distant metastases with a single imaging procedure are attractive, especially because the symptoms may not enable the physician to make a correct identification of the organ systems affected by metastases. Neumann and Hoffer state that at present conventional Ga-67 scanning techniques cannot be recommended for preoperative staging of mediastinal lymph node metastases in lung cancer patients. According to Waxman, 67Ga scintigraphy, relative to other imaging modalities, is a sensitive indicator of hilar spread of a tumor. However, because of the normally high background activity within the sternum and spine, mediastinal abnormalities may be poorly detected. Since most pulmonary tumors metastasize via regional nodes to the pulmonary hilum and then to the mediastinum, the high sensitivity for the detection of pulmonary hilar abnormalities and the high specificity for detection of mediastinal lesions suggest that gallium scintigraphy is a valuable adjunctive test when used appropriately. The results obtained locally are probably the best guide for individual physicians in the selection of diagnostic tests for their patients. Gallium scans may thus be helpful in the clinical evaluation of patients with lung cancer. Although gallium scans identify mediastinal node involvement, there is considerable controversy over the relationship between the sensitivity and specificity of the method. By detecting distant extrathoracic metastases, the 67Ga scan may identify a small group of patients who can be spared a needless operation. 92 references.

  17. Noninvasive in vivo imaging reveals differences between tectorial membrane and basilar membrane traveling waves in the mouse cochlea.

    Science.gov (United States)

    Lee, Hee Yoon; Raphael, Patrick D; Park, Jesung; Ellerbee, Audrey K; Applegate, Brian E; Oghalai, John S

    2015-03-10

    Sound is encoded within the auditory portion of the inner ear, the cochlea, after propagating down its length as a traveling wave. For over half a century, vibratory measurements to study cochlear traveling waves have been made using invasive approaches such as laser Doppler vibrometry. Although these studies have provided critical information regarding the nonlinear processes within the living cochlea that increase the amplitude of vibration and sharpen frequency tuning, the data have typically been limited to point measurements of basilar membrane vibration. In addition, opening the cochlea may alter its function and affect the findings. Here we describe volumetric optical coherence tomography vibrometry, a technique that overcomes these limitations by providing depth-resolved displacement measurements at 200 kHz inside a 3D volume of tissue with picometer sensitivity. We studied the mouse cochlea by imaging noninvasively through the surrounding bone to measure sound-induced vibrations of the sensory structures in vivo, and report, to our knowledge, the first measures of tectorial membrane vibration within the unopened cochlea. We found that the tectorial membrane sustains traveling wave propagation. Compared with basilar membrane traveling waves, tectorial membrane traveling waves have larger dynamic ranges, sharper frequency tuning, and apically shifted positions of peak vibration. These findings explain discrepancies between previously published basilar membrane vibration and auditory nerve single unit data. Because the tectorial membrane directly overlies the inner hair cell stereociliary bundles, these data provide the most accurate characterization of the stimulus shaping the afferent auditory response available to date.

  18. Non-invasive imaging of tumors by monitoring autotaxin activity using an enzyme-activated near-infrared fluorogenic substrate.

    Directory of Open Access Journals (Sweden)

    Damian Madan

    Full Text Available Autotaxin (ATX, an autocrine motility factor that is highly upregulated in metastatic cancer, is a lysophospholipase D enzyme that produces the lipid second messenger lysophosphatidic acid (LPA from lysophosphatidylcholine (LPC. Dysregulation of the lysolipid signaling pathway is central to the pathophysiology of numerous cancers, idiopathic pulmonary fibrosis, rheumatoid arthritis, and other inflammatory diseases. Consequently, the ATX/LPA pathway has emerged as an important source of biomarkers and therapeutic targets. Herein we describe development and validation of a fluorogenic analog of LPC (AR-2 that enables visualization of ATX activity in vivo. AR-2 exhibits minimal fluorescence until it is activated by ATX, which substantially increases fluorescence in the near-infrared (NIR region, the optimal spectral window for in vivo imaging. In mice with orthotopic ATX-expressing breast cancer tumors, ATX activated AR-2 fluorescence. Administration of AR-2 to tumor-bearing mice showed high fluorescence in the tumor and low fluorescence in most healthy tissues with tumor fluorescence correlated with ATX levels. Pretreatment of mice with an ATX inhibitor selectively decreased fluorescence in the tumor. Together these data suggest that fluorescence directly correlates with ATX activity and its tissue expression. The data show that AR-2 is a non-invasive and selective tool that enables visualization and quantitation of ATX-expressing tumors and monitoring ATX activity in vivo.

  19. Fluorescence imaging for a noninvasive in vivo toxicity-test using a transgenic silkworm expressing green fluorescent protein.

    Science.gov (United States)

    Inagaki, Yoshinori; Matsumoto, Yasuhiko; Ishii, Masaki; Uchino, Keiro; Sezutsu, Hideki; Sekimizu, Kazuhisa

    2015-06-10

    In drug development, the toxicity of candidate chemicals must be carefully examined in an animal model. Here we developed a live imaging technique using silkworms for a noninvasive toxicity test applicable for drug screening. Injection of carbon tetrachloride, a tissue-injuring chemical, into transgenic silkworms expressing green fluorescent protein (GFP) induced leakage of GFP from the tissues into the hemolymph. The leakage of GFP was suppressed by pre-administration of either cimetidine, a cytochrome P450 inhibitor, or N-acetyl cysteine, a free-radical scavenger. The transgenic silkworm was made transparent by feeding a diet containing chemicals that inhibit uric acid deposition in the epithelial cells. In the transparent silkworms, GFP fluorescence in the fat body could be observed from outside the body. Injection of salicylic acid or iron sulfate, tissue-injuring chemicals, into the transparent silkworms decreased the fluorescence intensity of the GFP in the fat body. These findings suggest that the transparent GFP-expressing silkworm model is useful for evaluating the toxicity of chemicals that induce tissue injury.

  20. Noninvasive Cardiovascular Risk Assessment of the Asymptomatic Diabetic Patient: The Imaging Council of the American College of Cardiology.

    Science.gov (United States)

    Budoff, Matthew J; Raggi, Paolo; Beller, George A; Berman, Daniel S; Druz, Regina S; Malik, Shaista; Rigolin, Vera H; Weigold, Wm Guy; Soman, Prem

    2016-02-01

    Increased cardiovascular morbidity and mortality in patients with type 2 diabetes is well established; diabetes is associated with at least a 2-fold increased risk of coronary heart disease. Approximately two-thirds of deaths among persons with diabetes are related to cardiovascular disease. Previously, diabetes was regarded as a "coronary risk equivalent," implying a high 10-year cardiovascular risk for every diabetes patient. Following the original study by Haffner et al., multiple studies from different cohorts provided varying conclusions on the validity of the concept of coronary risk equivalency in patients with diabetes. New guidelines have started to acknowledge the heterogeneity in risk and include different treatment recommendations for diabetic patients without other risk factors who are considered to be at lower risk. Furthermore, guidelines have suggested that further risk stratification in patients with diabetes is warranted before universal treatment. The Imaging Council of the American College of Cardiology systematically reviewed all modalities commonly used for risk stratification in persons with diabetes mellitus and summarized the data and recommendations. This document reviews the evidence regarding the use of noninvasive testing to stratify asymptomatic patients with diabetes with regard to coronary heart disease risk and develops an algorithm for screening based on available data.

  1. Evaluation of bioluminescent imaging for noninvasive monitoring of colorectal cancer progression in the liver and its response to immunogene therapy

    Directory of Open Access Journals (Sweden)

    Gonzalez-Aparicio Manuela

    2009-01-01

    Full Text Available Abstract Background Bioluminescent imaging (BLI is based on the detection of light emitted by living cells expressing a luciferase gene. Stable transfection of luciferase in cancer cells and their inoculation into permissive animals allows the noninvasive monitorization of tumor progression inside internal organs. We have applied this technology for the development of a murine model of colorectal cancer involving the liver, with the aim of improving the pre-clinical evaluation of new anticancer therapies. Results A murine colon cancer cell line stably transfected with the luciferase gene (MC38Luc1 retains tumorigenicity in immunocompetent C57BL/6 animals. Intrahepatic inoculation of MC38Luc1 causes progressive liver infiltration that can be monitored by BLI. Compared with ultrasonography (US, BLI is more sensitive, but accurate estimation of tumor mass is impaired in advanced stages. We applied BLI to evaluate the efficacy of an immunogene therapy approach based on the liver-specific expression of the proinflammatory cytokine interleukin-12 (IL-12. Individualized quantification of light emission was able to determine the extent and duration of antitumor responses and to predict long-term disease-free survival. Conclusion We show that BLI is a rapid, convenient and safe technique for the individual monitorization of tumor progression in the liver. Evaluation of experimental treatments with complex mechanisms of action such as immunotherapy is possible using this technology.

  2. Advanced spectral imaging for noninvasive microanalysis of cultural heritage materials: review of application to documents in the U.S. Library of Congress.

    Science.gov (United States)

    France, Fenella G

    2011-06-01

    Hyperspectral imaging was originally developed for remote sensing and astronomical applications, but adaptations of this technology have been of great benefit to the preservation of cultural heritage. Developments in noninvasive analytical techniques have advanced the preservation of cultural heritage materials by enabling the identification and analysis of a range of materials, utilizing their unique spectral response to nondestructively determine chemical composition, and determining states of deterioration and change due to environmental conditions. When used as a tool for noninvasive characterization of cultural heritage, these spectral imaging systems allow the collection of chemical identification information about materials without sampling, which is a critical factor for cultural heritage materials. The United States Library of Congress has been developing the application of hyperspectral imaging to the preservation and analysis of cultural heritage materials as a powerful noncontact technique. It allows noninvasive characterization of materials, by identifying and characterizing colorants, inks, and substrates with narrow-band illumination to protect the object while also monitoring deterioration or changes due to exhibit and other environmental conditions. Contiguous illumination from the ultraviolet, visible, and infrared spectral regions allows the capture of lost, obscured, and deteriorated information. The resulting image cube allows greater capabilities for mapping and coordinating a range of complementary chemical and spectral analyses. The capabilities of this technique are illustrated by a review of results from analysis of the Waldseemüller World Map, the L'Enfant plan for Washington, D.C., and the first draft of the U.S. Declaration of Independence.

  3. Imaging of HCC—Current State of the Art

    Directory of Open Access Journals (Sweden)

    Christina Schraml

    2015-11-01

    Full Text Available Early diagnosis of hepatocellular carcinoma (HCC is crucial for optimizing treatment outcome. Ongoing advances are being made in imaging of HCC regarding detection, grading, staging, and also treatment monitoring. This review gives an overview of the current international guidelines for diagnosing HCC and their discrepancies as well as critically summarizes the role of magnetic resonance imaging (MRI and computed tomography (CT techniques for imaging in HCC. The diagnostic performance of MRI with nonspecific and hepatobililiary contrast agents and the role of functional imaging with diffusion-weighted imaging will be discussed. On the other hand, CT as a fast, cheap and easily accessible imaging modality plays a major role in the clinical routine work-up of HCC. Technical advances in CT, such as dual energy CT and volume perfusion CT, are currently being explored for improving detection, characterization and staging of HCC with promising results. Cone beam CT can provide a three-dimensional analysis of the liver with tumor and vessel characterization comparable to cross-sectional imaging so that this technique is gaining an increasing role in the peri-procedural imaging of HCC treated with interventional techniques.

  4. Non-invasive analysis of root-soil interaction using three complementary imaging approaches

    Science.gov (United States)

    Haber-Pohlmeier, Sabina; Tötzke, Christian; Pohlmeier, Andreas; Rudolph-Mohr, Nicole; Kardjilov, Nikolay; Lehmann, Eberhard; Oswald, Sascha E.

    2016-04-01

    Plant roots are known to modify physical, chemical and biological properties of the rhizosphere, thereby, altering conditions for water and nutrient uptake. We aim for capturing the dynamic processes occurring at the soil-root interface in situ. A combination of neutron (NI), magnetic resonance (MRI) and micro-focus X-ray tomography (CT) is applied to monitor the rhizosphere of young plants grown in sandy soil in cylindrical containers (diameter 3 cm). A novel transportable low field MRI system is operated directly at the neutron facility allowing for combined measurements of the very same sample capturing the same hydro-physiological state. The combination of NI, MRI and CT provides three-dimensional access to the root system in respect to structure and hydraulics of the rhizosphere and the transport of dissolved marker substances. The high spatial resolution of neutron imaging and its sensitivity for water can be exploited for the 3D analysis of the root morphology and detailed mapping of three-dimensional water content at the root soil interface and the surrounding soil. MRI has the potential to yield complementary information about the mobility of water, which can be bound in small pores or in the polymeric network of root exudates (mucilage layer). We inject combined tracers (GdDPTA or D2O) to study water fluxes through soil, rhizosphere and roots. Additional CT measurements reveal mechanical impacts of roots on the local microstructure of soil, e.g. showing soil compaction or the formation of cracks. We co-register the NT, MRI and CT data to integrate the complementary information into an aligned 3D data set. This allows, e.g., for co-localization of compacted soil regions or cracks with the specific local soil hydraulics, which is needed to distinguish the contribution of root exudation from mechanical impacts when interpreting altered hydraulic properties of the rhizosphere. Differences between rhizosphere and bulk soil can be detected and interpreted in

  5. Lorentz effect imaging of ionic currents in solution

    Science.gov (United States)

    Truong, Trong-Kha; Avram, Alexandru; Song, Allen W.

    2008-03-01

    Current functional MRI techniques relying on hemodynamic modulations are inherently limited in their ability to accurately localize neural activity in space and time. To address these limitations, we previously proposed a novel technique based on the Lorentz effect and demonstrated its ability to directly image minute electrical activity with a millisecond temporal resolution in gel phantoms containing conductive wires as well as in the human median nerve in vivo. To better characterize its contrast mechanism and ultimately further improve its sensitivity for in vivo applications, we now apply this technique to image ionic currents in solution, which serve as a better model for neural conduction in biological systems than the electronic currents in conductive wires used in previous phantom studies. Our results demonstrate that ionic currents with durations and current densities on the same order of magnitude as those induced by neuroelectric activity in nerve fibers and in the brain can be detected.

  6. Noninvasive Localization of Accessory Pathways in Patients with Wolff-Parkinson-White Syndrome: A Strain Imaging Study

    Directory of Open Access Journals (Sweden)

    Maryam Esmaeilzadeh

    2015-10-01

    Full Text Available Background: Noninvasive techniques for the localization of the accessory pathways (APs might help guide mapping procedures and ablation techniques. We sought to examine the diagnostic accuracy of strain imaging for the localization of the APs in Wolff-Parkinson-White syndrome.Methods: We prospectively studied 25 patients (mean age = 32 ± 17 years, 58.3% men with evidence of pre-excitation on electrocardiography (ECG. Electromechanical interval was defined as the time difference between the onset of delta wave and the onset of regional myocardial contraction. Time differences between the onset of delta wave (δ and the onset of regional myocardial contraction (δ-So, peak systolic motion (δ-Sm, regional strain (δ-ε, peak strain (δ-εp, and peak strain rate (δ-SRp were measured.Results: There was a significant difference between time to onset of delta wave to onset of peak systolic motion (mean ± SD in the AP location (A and normal segments (B versus that in the normal volunteers (C [A: (57.08 ± 23.88 msec vs. B: (75.20 ± 14.75  vs. C: (72.9 0 ± 11.16; p value (A vs. B = 0.004 and p value (A vs. C = 0.18] and [A: (49.17 ± 35.79 vs. B: (67.60 ± 14.51 vs. C: (67.40 ± 6.06 msec; p value ( A vs. B < 0.001 and  p value (A vs. C = 0.12, respectively].Conclusion: Our study showed that strain imaging parameters [(δ-So and (δ-Strain] are superior to the ECG in the localization of the APs (84% vs. 76%.

  7. Cytoplasmically Retargeted HSV1-tk/GFP Reporter Gene Mutants for Optimization of Noninvasive Molecular-Genetic Imaging

    Directory of Open Access Journals (Sweden)

    Vladimir Ponomarev

    2003-05-01

    Full Text Available To optimize the sensitivity of imaging HSV1-tk/GFP reporter gene expression, a series of HSV1-tk/GFP mutants was developed with altered nuclear localization and better cellular enzymatic activity, compared to that of the native HSV1-tk/GFP fusion protein (HSVi-tk/GFP. Several modifications of HSV1-tk/GFP reporter gene were performed, including targeted inactivating mutations in the nuclear localization signal (NLS, the addition of a nuclear export signal (NES, a combination of both mutation types, and a truncation of the first 135 by of the native hsvl-tk coding sequence containing a “cryptic” testicular promoter and the NLS. A recombinant HSV1-tk/GFP protein and a highly sensitive sandwich enzyme-linked immunosorbent assay for HSV1-tk/GFP were developed to quantitate the amount of reporter gene product in different assays to allow normalization of the data. These different mutations resulted in various degrees of nuclear clearance, predominant cytoplasmic distribution, and increased total cellular enzymatic activity of the HSV1-tk/GFP mutants, compared to native HSV1-tk/GFP when expressed at the same levels. This appears to be the result of improved metabolic bioavailability of cytoplasmically retargeted mutant HSV1-tk/GFP enzymes for reaction with the radiolabeled probe (e.g., FIAU. The analysis of enzymatic properties of different HSV1-tk/GFP mutants using FIAU as a substrate revealed no significant differences from that of the native HSV1-tk/GFP. Improved total cellular enzymatic activity of cytoplasmically retargeted HSV1-tk/GFP mutants observed in vitro was confirmed by noninvasive imaging of transduced subcutaneous tumor xenografts bearing these reporters using [131I]FIAU and γ-camera.

  8. Assessment of disease activity in patients with rheumatoid arthritis using optical spectral transmission measurements, a non-invasive imaging technique

    Science.gov (United States)

    van Onna, M; Ten Cate, D F; Tsoi, K L; Meier, A J L; Jacobs, J W G; Westgeest, A A A; Meijer, P B L; van Beek, M C; Rensen, W H J; Bijlsma, J W J

    2016-01-01

    Objectives In rheumatoid arthritis (RA), treat-to-target strategies require instruments for valid detection of joint inflammation. Therefore, imaging modalities are increasingly used in clinical practice. Optical spectral transmission (OST) measurements are non-invasive and fast and may therefore have benefits over existing imaging modalities. We tested whether OST could measure disease activity validly in patients with RA. Methods In 59 patients with RA and 10 patients with arthralgia, OST, joint counts, Disease Activity Score (DAS) 28 and ultrasonography (US) were performed. Additionally, MRI was performed in patients with DAS28<2.6. We developed and validated within the same cohort an algorithm for detection of joint inflammation by OST with US as reference. Results At the joint level, OST and US performed similarly inproximal interphalangeal-joints (area under the receiver-operating curve (AUC) of 0.79, p<0.0001) andmetacarpophalangeal joints (AUC 0.78, p<0.0001). Performance was less similar in wrists (AUC 0.62, p=0.006). On the patient level, OST correlated moderately with clinical examination (DAS28 r=0.42, p=0.001), and US scores (r=0.64, p<0.0001). Furthermore, in patients with subclinical and low disease activity, there was a correlation between OST and MRI synovitis score (RAMRIS (Rheumatoid Arthritis MRI Scoring) synovitis), r=0.52, p=0.005. Conclusions In this pilot study, OST performed moderately in the detection of joint inflammation in patients with RA. Further studies are needed to determine the diagnostic performance in a new cohort of patients with RA. PMID:26452538

  9. Non-invasive detection of aflatoxin-contaminated figs using fluorescence and multispectral imaging.

    Science.gov (United States)

    Kalkan, Habil; Güneş, Ali; Durmuş, Efkan; Kuşçu, Alper

    2014-01-01

    Agricultural products are prone to aflatoxin (AF)-producing moulds (Aspergillus flavus, A. parasiticus) during harvesting, drying, processing and also storage. AF is a mycotoxin that may cause liver cancer when consumed in amounts higher than allowed limits. Figs, like other agricultural products, are mostly affected by AF-producing moulds and these moulds usually produce kojic acid together with AF. Kojic acid is a fluorescent compound and exhibiting bright greenish yellow fluorescence (BGYF) under ultraviolet (UV) light. Using this fluorescence property, fig-processing plants manually select and remove the BGYF+ figs to reduce the AF level of the processed figs. Although manual selection is based on subjective criteria and strongly depends on the expertise level of the workers, it is known as the most effective way of removing AF-contaminated samples. However, during manual selection, workers are exposed to UV radiation and this brings skin health problems. In this study, we individually investigated the figs to measure their fluorescence level, surface mould concentration and AF levels and noted a strong correlation between mould concentration and BGYF and AF, and BGYF and surface. In addition to a pairwise correlation, we proposed a machine-vision and machine-learning approach to detect the AF-contaminated figs using their multispectral images under UV light. The figs were classified in two different approaches considering their surface mould and AF level with error rates of 9.38% and 11.98%, respectively.

  10. Non-invasive imaging of the crystalline structure within a human tooth.

    Science.gov (United States)

    Egan, Christopher K; Jacques, Simon D M; Di Michiel, Marco; Cai, Biao; Zandbergen, Mathijs W; Lee, Peter D; Beale, Andrew M; Cernik, Robert J

    2013-09-01

    The internal crystalline structure of a human molar tooth has been non-destructively imaged in cross-section using X-ray diffraction computed tomography. Diffraction signals from high-energy X-rays which have large attenuation lengths for hard biomaterials have been collected in a transmission geometry. Coupling this with a computed tomography data acquisition and mathematically reconstructing their spatial origins, diffraction patterns from every voxel within the tooth can be obtained. Using this method we have observed the spatial variations of some key material parameters including nanocrystallite size, organic content, lattice parameters, crystallographic preferred orientation and degree of orientation. We have also made a link between the spatial variations of the unit cell lattice parameters and the chemical make-up of the tooth. In addition, we have determined how the onset of tooth decay occurs through clear amorphization of the hydroxyapatite crystal, and we have been able to map the extent of decay within the tooth. The described method has strong prospects for non-destructive probing of mineralized biomaterials.

  11. Comparative performance of image fusion methodologies in eddy current testing

    Directory of Open Access Journals (Sweden)

    S. Thirunavukkarasu

    2012-12-01

    Full Text Available Image fusion methodologies have been studied for improving the detectability of eddy current Nondestructive Testing (NDT. Pixel level image fusion has been performed on C-scan eddy current images of a sub-surface defect at two different frequencies. Multi-resolution analysis based Laplacian pyramid and wavelet fusion methodologies, statistical inference based Bayesian fusion and Principal Component Analysis (PCA based fusion methodologies have been studied towards improving the detectability of defects. The performance of the fusion methodologies has been compared using image metrics such as SNR and entropy. Bayesian based fusion methodology has shown better performance as compared to other methodologies with 33.75 dB improvement in the SNR and an improvement of 3.22 in the entropy.

  12. A non-invasive thermal drift compensation technique applied to a spin-valve magnetoresistive current sensor

    National Research Council Canada - National Science Library

    Sánchez Moreno, Jaime; Ramírez Muñoz, Diego; Cardoso, Susana; Casans Berga, Silvia; Navarro Antón, Asunción Edith; Peixeiro de Freitas, Paulo Jorge

    2011-01-01

    .... Experimental results are shown using a microfabricated spin-valve MR current sensor. The temperature compensation has been solved in the interval from 0 °C to 70 °C measuring currents from -10 A to +10 A.

  13. Structure-driven design of radionuclide tracers for non-invasive imaging of uPAR and targeted radiotherapy. The tale of a synthetic peptide antagonist

    DEFF Research Database (Denmark)

    Ploug, Michael

    2013-01-01

    as for monitoring the effects of such treatments by non-invasive imaging using e.g. positron emission tomography. This mini-review will focus on recent advancements in translational research devoted to non-invasive targeting of uPAR, with a view to molecular imaging of its expression in live individuals as well......-function relationships in uPAR has been refined to such a level that a rational design of uPAR function as well as compounds specifically targeting defined functions of uPAR are now realistic options. This knowledge opens new avenues for developing therapeutic intervention regimens targeting uPAR as well...... as specific eradication of these cells by targeted radiotherapy....

  14. Current trends in medical image registration and fusion

    Directory of Open Access Journals (Sweden)

    Fatma El-Zahraa Ahmed El-Gamal

    2016-03-01

    Full Text Available Recently, medical image registration and fusion processes are considered as a valuable assistant for the medical experts. The role of these processes arises from their ability to help the experts in the diagnosis, following up the diseases’ evolution, and deciding the necessary therapies regarding the patient’s condition. Therefore, the aim of this paper is to focus on medical image registration as well as medical image fusion. In addition, the paper presents a description of the common diagnostic images along with the main characteristics of each of them. The paper also illustrates most well-known toolkits that have been developed to help the working with the registration and fusion processes. Finally, the paper presents the current challenges associated with working with medical image registration and fusion through illustrating the recent diseases/disorders that were addressed through such an analyzing process.

  15. CT myocardial perfusion imaging: current status and future directions.

    Science.gov (United States)

    Williams, M C; Newby, D E

    2016-08-01

    Computed tomography (CT) imaging of the heart has advanced rapidly, and it is now possible to perform a comprehensive assessment at a low radiation dose. CT myocardial perfusion imaging can provide additive information to CT coronary angiography, and is particularly useful in patients with heavily calcified coronary arteries or coronary artery stents. A number of protocols are now available for CT myocardial perfusion including static, dynamic, and dual-energy techniques. This review will discuss the current status of CT myocardial perfusion imaging, its clinical application, and future directions for this technology.

  16. In Vivo Noninvasive Imaging of Healthy Lower Lip Mucosa: A Correlation Study between High-Definition Optical Coherence Tomography, Reflectance Confocal Microscopy, and Histology

    Directory of Open Access Journals (Sweden)

    Alejandra García-Hernández

    2013-01-01

    Full Text Available In recent years, technology has allowed the development of new diagnostic techniques which allow real-time, in vivo, noninvasive evaluation of morphological changes in tissue. This study compares and correlates the images and findings obtained by high-definition optical coherence tomography (HD-OCT and reflectance confocal microscopy (RCM with histology in normal healthy oral mucosa. The healthy lip mucosa of ten adult volunteers was imaged with HD-OCT and RCM. Each volunteer was systematically evaluated by RCM starting in the uppermost part of the epithelium down to the lamina propia. Afterwards, volunteers were examined with a commercially available full-field HD-OCT system using both the “slice” and the “en-face” mode. A “punch” biopsy of the lower lip mucosa was obtained and prepared for conventional histology. The architectural overview offered by “slice” mode HD-OCT correlates with histologic findings at low magnification. In the superficial uppermost layers of the epithelium, RCM imaging provided greater cellular detail than histology. As we deepened into the suprabasal layers, the findings are in accordance with physiological cellular differentiation and correlate with the images obtained from conventional histology. The combined use of these two novel non-invasive imaging techniques provides morphological imaging with sufficient resolution and penetration depth, resulting in quasihistological images.

  17. A matter of collection and detection for intraoperative and noninvasive near-infrared fluorescence molecular imaging: To see or not to see?

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M., E-mail: Eva.Sevick@uth.tmc.edu [Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, Texas 77030 (United States)

    2014-02-15

    Purpose: Although fluorescence molecular imaging is rapidly evolving as a new combinational drug/device technology platform for molecularly guided surgery and noninvasive imaging, there remains no performance standards for efficient translation of “first-in-humans” fluorescent imaging agents using these devices. Methods: The authors employed a stable, solid phantom designed to exaggerate the confounding effects of tissue light scattering and to mimic low concentrations (nM–pM) of near-infrared fluorescent dyes expected clinically for molecular imaging in order to evaluate and compare the commonly used charge coupled device (CCD) camera systems employed in preclinical studies and in human investigational studies. Results: The results show that intensified CCD systems offer greater contrast with larger signal-to-noise ratios in comparison to their unintensified CCD systems operated at clinically reasonable, subsecond acquisition times. Conclusions: Camera imaging performance could impact the success of future “first-in-humans” near-infrared fluorescence imaging agent studies.

  18. 7-Tesla Magnetic Resonance Imaging Precisely and Noninvasively Reflects Inflammation and Remodeling of the Skeletal Muscle in a Mouse Model of Antisynthetase Syndrome

    Directory of Open Access Journals (Sweden)

    Clara Sciorati

    2014-01-01

    Full Text Available Inflammatory myopathies comprise heterogeneous disorders. Their etiopathogenesis is poorly understood, because of the paucity of informative experimental models and of approaches for the noninvasive study of inflamed tissues. Magnetic resonance imaging (MRI provides information about the state of the skeletal muscle that reflects various facets of inflammation and remodeling. This technique has been scarcely used in experimental models of inflammatory myopathies. We characterized the performance of MRI in a well-established mouse model of myositis and the antisynthetase syndrome, based on the immunization of wild-type mice with the amino-terminal fragment of histidyl-tRNA synthetase (HisRS. Over an eight-week period following myositis induction, MRI enabled precise identification of pathological events taking place in muscle tissue. Areas of edema and of active inflammation identified by histopathology paralleled muscle modifications detected noninvasively by MRI. Muscles changes were chronologically associated with the establishment of autoimmunity, as reflected by the development of anti-HisRS antibodies in the blood of immunized mice. MR imaging easily appreciated muscle damage and remodeling even if actual disruption of myofiber integrity (as assessed by serum concentrations of creatinine phosphokinase was limited. Thus, MR imaging represents an informative and noninvasive analytical tool for studying in vivo immune-mediated muscle involvement.

  19. A preclinical model for noninvasive imaging of hypoxia-induced gene expression; comparison with an exogenous marker of tumor hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Wen Bixiu; Burgman, Paul; Zanzonico, Pat; O' Donoghue, Joseph; Li, Gloria C.; Ling, C. Clifton [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics, New York (United States); Cai Shangde; Finn, Ron [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York (United States); Serganova, Inna [Memorial Sloan-Kettering Cancer Center, Department of Neurology, New York (United States); Blasberg, Ronald; Gelovani, Juri [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York (United States); Memorial Sloan-Kettering Cancer Center, Department of Neurology, New York (United States)

    2004-11-01

    Hypoxia is associated with tumor aggressiveness and is an important cause of resistance to radiation therapy and chemotherapy. Assays of tumor hypoxia could provide selection tools for hypoxia-modifying treatments. The purpose of this study was to develop and characterize a rodent tumor model with a reporter gene construct that would be transactivated by the hypoxia-inducible molecular switch, i.e., the upregulation of HIF-1. The reporter gene construct is the herpes simplex virus 1-thymidine kinase (HSV1-tk) fused with the enhanced green fluorescent protein (eGFP) under the regulation of an artificial hypoxia-responsive enhancer/promoter. In this model, tumor hypoxia would up-regulate HIF-1, and through the hypoxia-responsive promoter transactivate the HSV1-tkeGFPfusion gene. The expression of this reporter gene can be assessed with the {sup 124}I-labeled reporter substrate 2'-fluoro-2'-deoxy-1-{beta}-d-arabinofuranosyl-5-iodouracil ({sup 124}I-FIAU), which is phosphorylated by the HSV1-tk enzyme and trapped in the hypoxic cells. Animal positron emission tomography (microPET) and phosphor plate imaging (PPI) were used in this study to visualize the trapped {sup 124}I-FIAU, providing a distribution of the hypoxia-induced molecular events. The distribution of {sup 124}I-FIAU was also compared with that of an exogenous hypoxic cell marker, {sup 18}F-fluoromisonidazole (FMISO). Our results showed that {sup 124}I-FIAU microPET imaging of the hypoxia-induced reporter gene expression is feasible, and that the intratumoral distributions of {sup 124}I-FIAU and {sup 18}F-FMISO are similar. In tumor sections, detailed radioactivity distributions were obtained with PPI which also showed similarity between {sup 124}I-FIAU and {sup 18}F-FMISO. This reporter system is sufficiently sensitive to detect hypoxia-induced transcriptional activation by noninvasive imaging and might provide a valuable tool in studying tumor hypoxia and in validating existing and future

  20. Non-invasive mapping of bilateral motor speech areas using navigated transcranial magnetic stimulation and functional magnetic resonance imaging.

    Science.gov (United States)

    Könönen, Mervi; Tamsi, Niko; Säisänen, Laura; Kemppainen, Samuli; Määttä, Sara; Julkunen, Petro; Jutila, Leena; Äikiä, Marja; Kälviäinen, Reetta; Niskanen, Eini; Vanninen, Ritva; Karjalainen, Pasi; Mervaala, Esa

    2015-06-15

    Navigated transcranial magnetic stimulation (nTMS) is a modern precise method to activate and study cortical functions noninvasively. We hypothesized that a combination of nTMS and functional magnetic resonance imaging (fMRI) could clarify the localization of functional areas involved with motor control and production of speech. Navigated repetitive TMS (rTMS) with short bursts was used to map speech areas on both hemispheres by inducing speech disruption during number recitation tasks in healthy volunteers. Two experienced video reviewers, blinded to the stimulated area, graded each trial offline according to possible speech disruption. The locations of speech disrupting nTMS trials were overlaid with fMRI activations of word generation task. Speech disruptions were produced on both hemispheres by nTMS, though there were more disruptive stimulation sites on the left hemisphere. Grade of the disruptions varied from subjective sensation to mild objectively recognizable disruption up to total speech arrest. The distribution of locations in which speech disruptions could be elicited varied among individuals. On the left hemisphere the locations of disturbing rTMS bursts with reviewers' verification followed the areas of fMRI activation. Similar pattern was not observed on the right hemisphere. The reviewer-verified speech disruptions induced by nTMS provided clinically relevant information, and fMRI might explain further the function of the cortical area. nTMS and fMRI complement each other, and their combination should be advocated when assessing individual localization of speech network. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Noninvasive image derived heart input function for CMRglc measurements in small animal slow infusion FDG PET studies

    Science.gov (United States)

    Xiong, Guoming; Cumming, Paul; Todica, Andrei; Hacker, Marcus; Bartenstein, Peter; Böning, Guido

    2012-12-01

    Absolute quantitation of the cerebral metabolic rate for glucose (CMRglc) can be obtained in positron emission tomography (PET) studies when serial measurements of the arterial [18F]-fluoro-deoxyglucose (FDG) input are available. Since this is not always practical in PET studies of rodents, there has been considerable interest in defining an image-derived input function (IDIF) by placing a volume of interest (VOI) within the left ventricle of the heart. However, spill-in arising from trapping of FDG in the myocardium often leads to progressive contamination of the IDIF, which propagates to underestimation of the magnitude of CMRglc. We therefore developed a novel, non-invasive method for correcting the IDIF without scaling to a blood sample. To this end, we first obtained serial arterial samples and dynamic FDG-PET data of the head and heart in a group of eight anaesthetized rats. We fitted a bi-exponential function to the serial measurements of the IDIF, and then used the linear graphical Gjedde-Patlak method to describe the accumulation in myocardium. We next estimated the magnitude of myocardial spill-in reaching the left ventricle VOI by assuming a Gaussian point-spread function, and corrected the measured IDIF for this estimated spill-in. Finally, we calculated parametric maps of CMRglc using the corrected IDIF, and for the sake of comparison, relative to serial blood sampling from the femoral artery. The uncorrected IDIF resulted in 20% underestimation of the magnitude of CMRglc relative to the gold standard arterial input method. However, there was no bias with the corrected IDIF, which was robust to the variable extent of myocardial tracer uptake, such that there was a very high correlation between individual CMRglc measurements using the corrected IDIF with gold-standard arterial input results. Based on simulation, we furthermore find that electrocardiogram-gating, i.e. ECG-gating is not necessary for IDIF quantitation using our approach.

  2. Feasibility of noninvasive quantitative measurements of intrarenal R(2) ' in humans using an asymmetric spin echo echo planar imaging sequence.

    Science.gov (United States)

    Zhang, Xiaodong; Zhang, Yudong; Yang, Xuedong; Wang, Xiaoying; An, Hongyu; Zhang, Jue; Fang, Jing

    2013-01-01

    The purpose of this study was to demonstrate the feasibility of an asymmetric spin echo (ASE) single-shot echo planar imaging (EPI) sequence for the noninvasive quantitative measurement of intrarenal R(2) ' in humans within 20 s. The reproducibility of R(2) ' measurements with the ASE-EPI sequence was assessed in nine healthy young subjects in repeated studies conducted over three consecutive days. Moreover, we also evaluated whether the ASE-EPI sequence-measured R(2) ' reflected the intrarenal oxygenation changes induced by furosemide in another group of normal human subjects (n = 10). Different flow attenuation gradients (b = 0, 40 and 80 s/mm(2) ) were utilized to examine the impact of the intravascular signal contribution on the estimation of intrarenal R(2) '. In the absence of flow dephasing gradients (b = 0 s/mm(2) ), the computed coefficient of variation (CV) of R(2) ' was 21.31 ± 4.52%, and the estimated R(2) ' value decreased slightly, but not statistically significantly (p > 0.05), after the administration of furosemide in the medullary region. However, CV of R(2) ' was much smaller in the presence of flow dephasing gradients (9.68 ± 3.58% with b = 40 s/mm(2) and 10.50 ± 3.62% with b = 80 s/mm(2) ). Moreover, a significant reduction in R(2) ' in the renal medulla was obtained (p R(2) ' measurements did not differ between the b = 40 s/mm(2) and b = 80 s/mm(2) scans, suggesting that small diffusion gradients were sufficient to minimize the intravascular signal contribution. In summary, we have demonstrated that renal R(2) ' can be obtained rapidly using an ASE-EPI sequence. The measurement was highly reproducible and reflected the expected intrarenal oxygenation changes induced by furosemide.

  3. Lessons from the masters current concepts in astronomical image processing

    CERN Document Server

    2013-01-01

    There are currently thousands of amateur astronomers around the world engaged in astrophotography at increasingly sophisticated levels. Their ranks far outnumber professional astronomers doing the same and their contributions both technically and artistically are the dominant drivers of progress in the field today. This book is a unique collaboration of individuals, all world-renowned in their particular area, and covers in detail each of the major sub-disciplines of astrophotography. This approach offers the reader the greatest opportunity to learn the most current information and the latest techniques directly from the foremost innovators in the field today.   The book as a whole covers all types of astronomical image processing, including processing of eclipses and solar phenomena, extracting detail from deep-sky, planetary, and widefield images, and offers solutions to some of the most challenging and vexing problems in astronomical image processing. Recognized chapter authors include deep sky experts su...

  4. High-resolution harmonics ultrasound imaging for non-invasive characterization of wound healing in a pre-clinical swine model.

    Directory of Open Access Journals (Sweden)

    Surya C Gnyawali

    Full Text Available This work represents the first study employing non-invasive high-resolution harmonic ultrasound imaging to longitudinally characterize skin wound healing. Burn wounds (day 0-42, on the dorsum of a domestic Yorkshire white pig were studied non-invasively using tandem digital planimetry, laser speckle imaging and dual mode (B and Doppler ultrasound imaging. Wound depth, as measured by B-mode imaging, progressively increased until day 21 and decreased thereafter. Initially, blood flow at the wound edge increased up to day 14 and subsequently regressed to baseline levels by day 21, when the wound was more than 90% closed. Coinciding with regression of blood flow at the wound edge, there was an increase in blood flow in the wound bed. This was observed to regress by day 42. Such changes in wound angiogenesis were corroborated histologically. Gated Doppler imaging quantitated the pulse pressure of the primary feeder artery supplying the wound site. This pulse pressure markedly increased with a bimodal pattern following wounding connecting it to the induction of wound angiogenesis. Finally, ultrasound elastography measured tissue stiffness and visualized growth of new tissue over time. These studies have elegantly captured the physiological sequence of events during the process of wound healing, much of which is anticipated based on certain dynamics in play, to provide the framework for future studies on molecular mechanisms driving these processes. We conclude that the tandem use of non-invasive imaging technologies has the power to provide unprecedented insight into the dynamics of the healing skin tissue.

  5. Acute stroke magnetic resonance imaging: current status and future perspective.

    Science.gov (United States)

    Kloska, Stephan P; Wintermark, Max; Engelhorn, Tobias; Fiebach, Jochen B

    2010-03-01

    Cerebral stroke is one of the most frequent causes of permanent disability or death in the western world and a major burden in healthcare system. The major portion is caused by acute ischemia due to cerebral artery occlusion by a clot. The minority of strokes is related to intracerebral hemorrhage or other sources. To limit the permanent disability in ischemic stroke patients resulting from irreversible infarction of ischemic brain tissue, major efforts were made in the last decade. To extend the time window for thrombolysis, which is the only approved therapy, several imaging parameters in computed tomography and magnetic resonance imaging (MRI) have been investigated. However, the current guidelines neglect the fact that the portion of potentially salvageable ischemic tissue (penumbra) is not dependent on the time window but the individual collateral blood flow. Within the last years, the differentiation of infarct core and penumbra with MRI using diffusion-weighted images (DWI) and perfusion imaging (PI) with parameter maps was established. Current trials transform these technical advances to a redefined patient selection based on physiological parameters determined by MRI. This review article presents the current status of MRI for acute stroke imaging. A special focus is the ischemic stroke. In dependence on the pathophysiology of cerebral ischemia, the basic principle and diagnostic value of different MRI sequences are illustrated. MRI techniques for imaging of the main differential diagnoses of ischemic stroke are mentioned. Moreover, perspectives of MRI for imaging-based acute stroke treatment as well as monitoring of restorative stroke therapy from recent trials are discussed.

  6. Acute stroke magnetic resonance imaging: current status and future perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kloska, Stephan P. [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); University of Muenster, Department of Clinical Radiology, Muenster (Germany); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States); Engelhorn, Tobias [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); Fiebach, Jochen B. [Charite, Universitaetsmedizin Berlin, Campus Benjamin Franklin, Center for Stroke Research Berlin (CSB), Department of Neurology, Berlin (Germany)

    2010-03-15

    Cerebral stroke is one of the most frequent causes of permanent disability or death in the western world and a major burden in healthcare system. The major portion is caused by acute ischemia due to cerebral artery occlusion by a clot. The minority of strokes is related to intracerebral hemorrhage or other sources. To limit the permanent disability in ischemic stroke patients resulting from irreversible infarction of ischemic brain tissue, major efforts were made in the last decade. To extend the time window for thrombolysis, which is the only approved therapy, several imaging parameters in computed tomography and magnetic resonance imaging (MRI) have been investigated. However, the current guidelines neglect the fact that the portion of potentially salvageable ischemic tissue (penumbra) is not dependent on the time window but the individual collateral blood flow. Within the last years, the differentiation of infarct core and penumbra with MRI using diffusion-weighted images (DWI) and perfusion imaging (PI) with parameter maps was established. Current trials transform these technical advances to a redefined patient selection based on physiological parameters determined by MRI. This review article presents the current status of MRI for acute stroke imaging. A special focus is the ischemic stroke. In dependence on the pathophysiology of cerebral ischemia, the basic principle and diagnostic value of different MRI sequences are illustrated. MRI techniques for imaging of the main differential diagnoses of ischemic stroke are mentioned. Moreover, perspectives of MRI for imaging-based acute stroke treatment as well as monitoring of restorative stroke therapy from recent trials are discussed. (orig.)

  7. Noninvasive in vivo magnetic resonance imaging of injury-induced neointima formation in the carotid artery of the apolipoprotein-E null mouse.

    Science.gov (United States)

    Manka, D R; Gilson, W; Sarembock, I; Ley, K; Berr, S S

    2000-11-01

    Mice deficient in apolipoprotein-E (apoE) experience severe hypercholesterolemia, are prone to atherosclerosis, and recently have emerged as a powerful tool in the study of plaque formation. In this study, we developed magnetic resonance (MR) imaging methods to detect the progression of atherosclerosis noninvasively in a mouse model of arterial injury. Four 14-week-old apoE-deficient mice were imaged 5 weeks after beginning an atherogenic Western diet and 4 weeks after wire denudation injury of the left common carotid artery (LCCA). Information from several images was combined into high-information content images using methods previously developed. The image resolution was 47 x 47 x 750 microm(3). We acquired T1-, T2-, and proton density (PD)-weighted images (TR/TE 650/14, 2000/60, and 2000/14 msec, respectively). Each 8-bit image was placed in a separate color channel to produce a 24-bit color image (red = T1, green = PD, and blue = T2). The composite image created contrast between different tissue types that was superior to that of any single image and revealed significant luminal narrowing of the LCCA, but not the uninjured RCCA. MR images were compared with corresponding histopathology cross sections and luminal area measurements from each method correlated(r2= 0.61). Atherosclerotic luminal narrowing was successfully detected through MR imaging in a mouse model of arterial injury that is small, reproduces quickly, and lends itself to genetic analysis and manipulation.

  8. Noninvasive Multimodality Imaging of the Tumor Microenvironment: Registered Dynamic Magnetic Resonance Imaging and Positron Emission Tomography Studies of a Preclinical Tumor Model of Tumor Hypoxia

    Directory of Open Access Journals (Sweden)

    HyungJoon Cho

    2009-03-01

    Full Text Available In vivo knowledge of the spatial distribution of viable, necrotic, and hypoxic areas can provide prognostic information about the risk of developing metastases and regional radiation sensitivity and may be used potentially for localized dose escalation in radiation treatment. In this study, multimodality in vivo magnetic resonance imaging (MRI and positron emission tomography (PET imaging using stereotactic fiduciary markers in the Dunning R3327AT prostate tumor were performed, focusing on the relationship between dynamic contrast-enhanced (DCE MRI using Magnevist (Gd-DTPA and dynamic 18F-fluoromisonidazole (18F-Fmiso PET. The noninvasive measurements were verified using tumor tissue sections stained for hematoxylin/eosin and pimonidazole. To further validate the relationship between 18F-Fmiso and pimonidazole uptake, 18F digital autoradiography was performed on a selected tumor and compared with the corresponding pimonidazole-stained slices. The comparison of Akep values (kep = rate constant of movement of Gd-DTPA between the interstitial space and plasma and A = amplitude in the two-compartment model (Hoffmann U, Brix G, Knopp MV, Hess T and Lorenz WJ (1995. Magn Reson Med 33, 506– 514 derived from DCE-MRI studies and from early 18F-Fmiso uptake PET studies showed that tumor vasculature is a major determinant of early 18F-Fmiso uptake. A negative correlation between the spatial map of Akep and the slope map of late (last 1 hour of the dynamic PET scan 18F-Fmiso uptake was observed. The relationships between DCE-MRI and hematoxylin/eosin slices and between 18F-Fmiso PET and pimonidazole slices confirm the validity of MRI/PET measurements to image the tumor microenvironment and to identify regions of tumor necrosis, hypoxia, and well-perfused tissue.

  9. Current status of radionuclide imaging in valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, C.A.; Okada, R.D.; Pohost, G.M.

    1980-12-18

    The current state-of-the-art in radionuclide imaging of valvular heart disease is based on different angiographic patterns in three left-sided valve abnormalities: pressure overload, volume overload, and inflow obstruction. In pressure overload, the left ventricle has normal dimensions or is minimally dilated the volume overload involves a left ventricular dilatation with a normal or reduced ejection fraction at rest the left ventricular function in inflow obstruction is normal, but in some cases may be depressed. Radionuclide angiography evaluates the effect of a valve abnormality on cardiac chamber and function thallium-201 imaging diagnoses regional myocardial blood flow and cell integrity and can evaluate the associated coronary artery disease.

  10. A double-blind controlled clinical trial assessing the effect of topical gels on striae distensae (stretch marks): a non-invasive imaging, morphological and immunohistochemical study.

    Science.gov (United States)

    Ud-Din, Sara; McAnelly, Sarah-Louise; Bowring, Alison; Whiteside, Sigrid; Morris, Julie; Chaudhry, Iskander; Bayat, Ardeshir

    2013-09-01

    Striae distensae (SD) are cutaneous lesions often presenting post-pregnancy with atrophy and flattening of the epidermis. SD is poorly understood and treatment remains ill-defined. Our aim was to assess the effect of topical application of silicone gel compared with placebo on SD using non-invasive devices and by immunohistochemical analysis of sequential tissue biopsies in a double-blind controlled trial. Twenty volunteers massaged silicone and placebo gels into separate sides of the abdomen, daily for 6 weeks. Objective non-invasive imaging plus subjective self-assessment of SD were performed on days 0, 21, 42, 90, in addition to tissue biopsies on days 0 and 42. Non-invasive imaging demonstrated an increase in melanin and a decrease in haemoglobin, collagen and pliability over the 6-week period on both sides. Additionally, collagen levels in SD were significantly higher (p value = 0.001) and melanin levels lower (p value = 0.048) with silicone gel compared with placebo. Histological analysis revealed epidermal flattening with a reduction of rete ridges in SD on both sides. Vascular count significantly decreased with placebo gel (p = 0.002). Corroborating the clinical results, melanin levels increased, whilst collagen type 1 and elastin decreased on both sides. Non-invasive techniques showed that the application of silicone gel increased collagen levels and reduced pigmentation compared with placebo. However, both clinical and histological data revealed that melanin increased whilst collagen, elastin and pliability decreased over the 6-week period with both gels. Furthermore, vascularity significantly decreased with placebo gel. These findings provide preliminary evidence of the utility of topical gels in the clinical management of SD.

  11. Self-assembled dual-modality contrast agents for non-invasive stem cell tracking via near-infrared fluorescence and magnetic resonance imaging.

    Science.gov (United States)

    Liu, Hong; Tan, Yan; Xie, Lisi; Yang, Lei; Zhao, Jing; Bai, Jingxuan; Huang, Ping; Zhan, Wugen; Wan, Qian; Zou, Chao; Han, Yali; Wang, Zhiyong

    2016-09-15

    Stem cells hold great promise for treating various diseases. However, one of the main drawbacks of stem cell therapy is the lack of non-invasive image-tracking technologies. Although magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging have been employed to analyse cellular and subcellular events via the assistance of contrast agents, the sensitivity and temporal resolution of MRI and the spatial resolution of NIRF are still shortcomings. In this study, superparamagnetic iron oxide nanocrystals and IR-780 dyes were co-encapsulated in stearic acid-modified polyethylenimine to form a dual-modality contrast agent with nano-size and positive charge. These resulting agents efficiently labelled stem cells and did not influence the cellular viability and differentiation. Moreover, the labelled cells showed the advantages of dual-modality imaging in vivo.

  12. History of Mexican Easel Paintings from an Altarpiece Revealed by Non-invasive Terahertz Time-Domain Imaging

    Science.gov (United States)

    Gomez-Sepulveda, A. M.; Hernandez-Serrano, A. I.; Radpour, R.; Koch-Dandolo, C. L.; Rojas-Landeros, S. C.; Ascencio-Rojas, L. F.; Zarate, Alvaro; Hernandez, Gerardo; Gonzalez-Tirado, R. C.; Insaurralde-Caballero, M.; Castro-Camus, E.

    2016-12-01

    Four easel paintings attributed to Hermenegildo Bustos (Purísima del Rincón, Guanajuato, Mexico), one of the most renowned painters of the late nineteenth and early twentieth century Mexican art, have been investigated by means of terahertz time-domain imaging (THz-TDI) and standard imaging techniques, such as near-IR reflectography and X-ray radiography. The archival sources and the recent studies on the paintings suggest that the artworks were created in the eighteenth century and underwent several modifications since then until the intervention of Bustos who authored the currently visible depictions. By combining the records of the paintings obtained by imaging with the different methodologies, aspects of the previous depictions and further details on the paintings' history have been revealed, with THz-TDI playing a key role in attributing a chronological evolution of the images. The paintings of Purísima are the first THz-TDI-scanned paintings belonging to the Mexican cultural heritage.

  13. History of Mexican Easel Paintings from an Altarpiece Revealed by Non-invasive Terahertz Time-Domain Imaging

    Science.gov (United States)

    Gomez-Sepulveda, A. M.; Hernandez-Serrano, A. I.; Radpour, R.; Koch-Dandolo, C. L.; Rojas-Landeros, S. C.; Ascencio-Rojas, L. F.; Zarate, Alvaro; Hernandez, Gerardo; Gonzalez-Tirado, R. C.; Insaurralde-Caballero, M.; Castro-Camus, E.

    2017-04-01

    Four easel paintings attributed to Hermenegildo Bustos ( Purísima del Rincón, Guanajuato, Mexico), one of the most renowned painters of the late nineteenth and early twentieth century Mexican art, have been investigated by means of terahertz time-domain imaging (THz-TDI) and standard imaging techniques, such as near-IR reflectography and X-ray radiography. The archival sources and the recent studies on the paintings suggest that the artworks were created in the eighteenth century and underwent several modifications since then until the intervention of Bustos who authored the currently visible depictions. By combining the records of the paintings obtained by imaging with the different methodologies, aspects of the previous depictions and further details on the paintings' history have been revealed, with THz-TDI playing a key role in attributing a chronological evolution of the images. The paintings of Purísima are the first THz-TDI-scanned paintings belonging to the Mexican cultural heritage.

  14. Image analysis technique applied to lock-exchange gravity currents

    OpenAIRE

    Nogueira, Helena; Adduce, Claudia; Alves, Elsa; Franca, Rodrigues Pereira Da; Jorge, Mario

    2013-01-01

    An image analysis technique is used to estimate the two-dimensional instantaneous density field of unsteady gravity currents produced by full-depth lock-release of saline water. An experiment reproducing a gravity current was performed in a 3.0 m long, 0.20 m wide and 0.30 m deep Perspex flume with horizontal smooth bed and recorded with a 25 Hz CCD video camera under controlled light conditions. Using dye concentration as a tracer, a calibration procedure was established for each pixel in th...

  15. Noninvasive Characterization of the Effect of Varying PLGA Molecular Weight Blends on In Situ Forming Implant Behavior Using Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    Luis Solorio, Alexander M. Olear, Jesse I. Hamilton, Ravi B. Patel, Ashlei C. Beiswenger, Jon E. Wallace, Haoyan Zhou, Agata A. Exner

    2012-01-01

    Full Text Available In situ forming implants (ISFIs have shown promise in drug delivery applications due to their simple manufacturing and minimally invasive administration. Precise, reproducible control of drug release from ISFIs is essential to their successful clinical application. This study investigated the effect of varying the molar ratio of different molecular weight (Mw poly(D,L-lactic-co-glycolic acid (PLGA polymers within a single implant on the release of a small Mw mock drug (sodium fluorescein both in vitro and in vivo. Implants were formulated by dissolving three different PLGA Mw (15, 29, and 53kDa, as well as three 1:1 molar ratio combinations of each PLGA Mw in 1-methyl-2-pyrrolidinone (NMP with the mock drug fluorescein. Since implant morphology and microstructure during ISFI formation and degradation is a crucial determinant of implant performance, and the rate of phase inversion has been shown to have an effect on the implant microstructure, diagnostic ultrasound was used to noninvasively quantify the extent of phase inversion and swelling behavior in both environments. Implant erosion, degradation, as well as the in vitro and in vivo release profiles were also measured using standard techniques. A non-linear mathematical model was used to correlate the drug release behavior with polymer phase inversion, with all formulations yielding an R2 value greater than 0.95. Ultrasound was also used to create a 3D image reconstruction of an implant over a 12 day span. In this study, swelling and phase inversion were shown to be inversely related to the polymer Mw with 53kDa polymer implants increasing at an average rate of 9.4%/day compared with 18.6%/day in the case of the 15 kDa PLGA. Additionally the onset of erosion, complete phase inversion, and degradation facilitated release required 9 d for 53 kDa implants, while these same processes began 3 d after injection into PBS with the 15 kDa implants. It was also observed that PLGA blends generally had

  16. Noninvasive characterization of the effect of varying PLGA molecular weight blends on in situ forming implant behavior using ultrasound imaging.

    Science.gov (United States)

    Solorio, Luis; Olear, Alexander M; Hamilton, Jesse I; Patel, Ravi B; Beiswenger, Ashlei C; Wallace, Jon E; Zhou, Haoyan; Exner, Agata A

    2012-01-01

    In situ forming implants (ISFIs) have shown promise in drug delivery applications due to their simple manufacturing and minimally invasive administration. Precise, reproducible control of drug release from ISFIs is essential to their successful clinical application. This study investigated the effect of varying the molar ratio of different molecular weight (Mw) poly(D,L-lactic-co-glycolic acid) (PLGA) polymers within a single implant on the release of a small Mw mock drug (sodium fluorescein) both in vitro and in vivo. Implants were formulated by dissolving three different PLGA Mw (15, 29, and 53 kDa), as well as three 1:1 molar ratio combinations of each PLGA Mw in 1-methyl-2-pyrrolidinone (NMP) with the mock drug fluorescein. Since implant morphology and microstructure during ISFI formation and degradation is a crucial determinant of implant performance, and the rate of phase inversion has been shown to have an effect on the implant microstructure, diagnostic ultrasound was used to noninvasively quantify the extent of phase inversion and swelling behavior in both environments. Implant erosion, degradation, as well as the in vitro and in vivo release profiles were also measured using standard techniques. A non-linear mathematical model was used to correlate the drug release behavior with polymer phase inversion, with all formulations yielding an R(2) value greater than 0.95. Ultrasound was also used to create a 3D image reconstruction of an implant over a 12 day span. In this study, swelling and phase inversion were shown to be inversely related to the polymer Mw with 53 kDa polymer implants increasing at an average rate of 9.4%/day compared with 18.6%/day in the case of the 15 kDa PLGA. Additionally the onset of erosion, complete phase inversion, and degradation facilitated release required 9 d for 53 kDa implants, while these same processes began 3 d after injection into PBS with the 15 kDa implants. It was also observed that PLGA blends generally had

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

    Science.gov (United States)

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

    2016-04-28

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

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

    Institute of Scientific and Technical Information of China (English)

    Charis Bourgioti; Konstantinos Chatoupis; Lia Angela Moulopoulos

    2016-01-01

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

  19. Current and future trends in marine image annotation software

    Science.gov (United States)

    Gomes-Pereira, Jose Nuno; Auger, Vincent; Beisiegel, Kolja; Benjamin, Robert; Bergmann, Melanie; Bowden, David; Buhl-Mortensen, Pal; De Leo, Fabio C.; Dionísio, Gisela; Durden, Jennifer M.; Edwards, Luke; Friedman, Ariell; Greinert, Jens; Jacobsen-Stout, Nancy; Lerner, Steve; Leslie, Murray; Nattkemper, Tim W.; Sameoto, Jessica A.; Schoening, Timm; Schouten, Ronald; Seager, James; Singh, Hanumant; Soubigou, Olivier; Tojeira, Inês; van den Beld, Inge; Dias, Frederico; Tempera, Fernando; Santos, Ricardo S.

    2016-12-01

    Given the need to describe, analyze and index large quantities of marine imagery data for exploration and monitoring activities, a range of specialized image annotation tools have been developed worldwide. Image annotation - the process of transposing objects or events represented in a video or still image to the semantic level, may involve human interactions and computer-assisted solutions. Marine image annotation software (MIAS) have enabled over 500 publications to date. We review the functioning, application trends and developments, by comparing general and advanced features of 23 different tools utilized in underwater image analysis. MIAS requiring human input are basically a graphical user interface, with a video player or image browser that recognizes a specific time code or image code, allowing to log events in a time-stamped (and/or geo-referenced) manner. MIAS differ from similar software by the capability of integrating data associated to video collection, the most simple being the position coordinates of the video recording platform. MIAS have three main characteristics: annotating events in real time, posteriorly to annotation and interact with a database. These range from simple annotation interfaces, to full onboard data management systems, with a variety of toolboxes. Advanced packages allow to input and display data from multiple sensors or multiple annotators via intranet or internet. Posterior human-mediated annotation often include tools for data display and image analysis, e.g. length, area, image segmentation, point count; and in a few cases the possibility of browsing and editing previous dive logs or to analyze the annotations. The interaction with a database allows the automatic integration of annotations from different surveys, repeated annotation and collaborative annotation of shared datasets, browsing and querying of data. Progress in the field of automated annotation is mostly in post processing, for stable platforms or still images

  20. Exact temporal eddy current compensation in magnetic resonance imaging systems.

    Science.gov (United States)

    Morich, M A; Lampman, D A; Dannels, W R; Goldie, F D

    1988-01-01

    A step-response method has been developed to extract the properties (amplitudes and decay time constants) of intrinsic-eddy-current-sourced magnetic fields generated in whole-body magnetic resonance imaging systems when pulsed field gradients are applied. Exact compensation for the eddy-current effect is achieved through a polynomial rooting procedure and matrix inversion once the 2 N properties of the N-term decay process are known. The output of the inversion procedure yields the required characteristics of the filter for spectrum magnitude and phase equalization. The method is described for the general case along with experimental results for one-, two-, and three-term inversions. The method's usefulness is demonstrated for the usually difficult case of long-term (200-1000-ms) eddy-current compensation. Field-gradient spectral flatness measurements over 30 mHz-100 Hz are given to validate the method.

  1. Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation.

    Science.gov (United States)

    Fröhlich, Flavio

    2014-03-01

    Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.

  2. Non-invasive image-guided laser microsurgery by a dual-wavelength fiber laser and an integrated fiber-optic multi-modal system.

    Science.gov (United States)

    Tsai, Meng-Tsan; Li, Dean-Ru; Chan, Ming-Che

    2016-10-15

    A new approach to non-invasive image-guided laser micro-treatment is demonstrated by a dual-wavelength fiber laser source and an integrated fiber-based multi-modal system. The fiber-based source, operated in 1.55 and 1.2 μm simultaneously, was directly connected to an integrated fiber-based multi-modal system for imaging and laser micro-treatment at the same time. The 1.2 μm radiations, within the 1.2-1.35 μm bio-penetration window of skin, were utilized for spectral domain optical coherence tomography imaging. The 1.55 μm radiations, highly absorptive to waters, were utilized for laser microsurgery. The new approach, which is simple in configuration and accurately controls the positions and exposure time of the laser microsurgery, shows great promises for future clinical applications.

  3. A simple one-step method to prepare fluorescent carbon dots and their potential application in non-invasive glioma imaging

    Science.gov (United States)

    Ruan, Shaobo; Qian, Jun; Shen, Shun; Zhu, Jianhua; Jiang, Xinguo; He, Qin; Gao, Huile

    2014-08-01

    Fluorescent carbon dots (CD) possess impressive potential in bioimaging because of their low photobleaching, absence of optical blinking and good biocompatibility. However, their relatively short excitation/emission wavelengths restrict their application in in vivo imaging. In the present study, a kind of CD was prepared by a simple heat treatment method using glycine as the only precursor. The diameter of CD was lower than 5 nm, and the highest emission wavelength was 500 nm. However, at 600 nm, there was still a relatively strong fluorescent emission, suggesting CD could be used for in vivo imaging. Additionally, several experiments demonstrated that CD possessed good serum stability and low cytotoxicity. In vitro, CD could be taken up into C6 glioma cells in a time- and concentration-dependent manner, with both endosomes and mitochondria involved. In vivo, CD could be used for non-invasive glioma imaging because of its high accumulation in the glioma site of the brain, which was demonstrated by both in vivo imaging and ex vivo tissue imaging. Furthermore, the fluorescent distribution in tissue slices also showed CD distributed in glioma with high intensity, while with a low intensity in normal brain tissue. In conclusion, CD were prepared using a simple method with relatively long excitation and emission wavelengths and could be used for non-invasive glioma imaging.Fluorescent carbon dots (CD) possess impressive potential in bioimaging because of their low photobleaching, absence of optical blinking and good biocompatibility. However, their relatively short excitation/emission wavelengths restrict their application in in vivo imaging. In the present study, a kind of CD was prepared by a simple heat treatment method using glycine as the only precursor. The diameter of CD was lower than 5 nm, and the highest emission wavelength was 500 nm. However, at 600 nm, there was still a relatively strong fluorescent emission, suggesting CD could be used for in vivo imaging

  4. Visceral anatomy of ocean sunfish (Mola mola (L., 1758), Molidae, Tetraodontiformes) and angler (Lophius piscatorius (L., 1758), Lophiidae, Lophiiformes) investigated by non-invasive imaging techniques.

    Science.gov (United States)

    Chanet, Bruno; Guintard, Claude; Boisgard, Thierry; Fusellier, Marion; Tavernier, Cédric; Betti, Eric; Madec, Stéphane; Richaudeau, Yvan; Raphaël, Christian; Dettaï, Agnès; Lecointre, Guillaume

    2012-12-01

    The purpose of this work is to examine the gross visceral anatomy of ocean sunfish and angler using non-invasive imaging techniques: computed tomography imaging (CT) and magnetic resonance imaging (MRI). Similarities and differences in the internal organisation of these two species are verified. Both species lack a swimbladder and present a significant asymmetry in the hepatic lobes, an elongated bile duct terminating close to the stomach, a compact thyroid embedded in a blood lacuna, and very reduced brain and spinal cord. These observations are important in regard to the close relationships between Tetraodontiformes and Lophiiformes, established by several molecular works, but not yet confirmed by morpho-anatomical data. However the occurrence of these features has to be examined in other taxa before phylogenetic hypotheses are proposed. Copyright © 2012 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  5. Non-invasive temperature assessment at different tissue types based on average grey-level from B-mode ultrasonic images

    Science.gov (United States)

    Alvarenga, A. V.; Teixeira, C. A.; Von Krüger, M. A.; Pereira, W. C. A.

    2012-05-01

    The average grey-levels calculated from B-Mode images were assessed for non-invasive temperature estimation in a porcine tissue sample containing two different tissue types, fat and muscle. The porcine sample was subjected to heating and cooling procedures with temperature varying from 35°C to 42°C. The sample was continuously imaged with an ultrasound scanner, and simultaneously the temperature was measured at each 5 seconds using Type-T thermocouples. The result shows that the average grey-level (AVGL)/temperature relations are different for the two studied regions, where the muscle tissue tends to present a bigger AVGL variation than the fat tissue considering the same temperature variation. Besides, the average grey-level/temperature functions estimated for each tissue region presented fitting errors inferior to ± 0.21°C, indicating that it might be possible to track temperature changes from both tissues using AVGL. This result is innovative since it suggests that using the same B-mode image and an average grey-level/temperature function to each region it is possible to estimate non-invasively temperature variations from different tissue regions in the same tissue sample. Future work includes the investigation of the spatial limits of these average grey-level/temperature functions.

  6. A Preclinical Evaluation of Antrodia camphorata Alcohol Extracts in the Treatment of Non-Small Cell Lung Cancer Using Non-Invasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Jeng-Feng Chiou

    2011-01-01

    Full Text Available This study was carried out to provide a platform for the pre-clinical evaluation of anti-cancer properties of a unique CAM (complementary and alternative medicine agent, Antrodia camphorata alcohol extract (ACAE, in a mouse model with the advantageous non-invasive in vivo bioluminescence molecular imaging technology. In vitro analyses on the proliferation, migration/invasion, cell cycle and apoptosis were performed on ACAE-treated non-small cell lung cancer cells, H441GL and control CGL1 cells. In vivo, immune-deficient mice were inoculated subcutaneously with H441GL followed by oral gavages of ACAE. The effect of ACAE on tumor progression was monitored by non-invasive bioluminescence imaging. The proliferation and migration/invasion of H441GL cells were inhibited by ACAE in a dose-dependent manner. In addition, ACAE induced cell cycle arrest at G0/G1 phase and apoptosis in H441GL cells as shown by flow cytometric analysis, Annexin-V immunoflourescence and DNA fragmentation. In vivo bioluminescence imaging revealed that tumorigenesis was significantly retarded by oral treatment of ACAE in a dose-dependent fashion. Based on our experimental data, ACAE contains anti-cancer properties and could be considered as a potential CAM agent in future clinical evaluation.

  7. Non-invasive Florentine Renaissance Panel Painting Replica Structures Investigation by Using Terahertz Time-Domain Imaging (THz-TDI) Technique

    Science.gov (United States)

    Koch Dandolo, Corinna L.; Picollo, Marcello; Cucci, Costanza; Jepsen, Peter Uhd

    2016-11-01

    The potentials of the Terahertz Time-Domain Imaging (THz-TDI) technique for a non-invasive inspection of panel paintings have been considered in detail. The THz-TD data acquired on a replica of a panel painting made in imitation of Italian Renaissance panel paintings were processed in order to provide insights as to the limits and potentials of the technique in detecting different kinds of underdrawings and paint layers. Constituent layers, construction techniques, and anomalies were identified and localized by interpreting the extracted THz dielectric stratigraphy.

  8. Gamna-Gandy bodies of the spleen detected with susceptibility weighted imaging: maybe a new potential non-invasive marker of esophageal varices.

    Directory of Open Access Journals (Sweden)

    Jiuquan Zhang

    Full Text Available BACKGROUND/OBJECTIVES: Portal hypertension (PH is a clinical sequelae of liver cirrhosis, and bleeding from esophageal varices (EV is a serious complication of PH with significant morbidity and mortality. The aims of this study were to assess the ability of 2D multislice breath-hold susceptibility weighted imaging (SWI to detect Gamna-Gandy bodies (GGBs in the spleens of patients with PH and to evaluate the potential role of GGB number as a non-invasive marker of PH and EV. MATERIALS AND METHODS: T1-, T2- and T2(*-weighted imaging and SWI were performed on 135 patients with PH and on 37 control individuals. Platelet counts were collected from all PH patients. Two radiologists analyzed all magnetic resonance imaging (MRI data, and measured the portal vein diameter, splenic index (SI, and platelet count/spleen diameter ratio. The numbers of patients with GGBs in the spleen were determined, and the numbers of GGB were counted in the four MRI sequences in GGB-positive patients. The portal vein diameter, SI, platelet count, and platelet count/spleen diameter ratio of control individuals were compared with those of GGB-negative and GGB-positive patients on SWI images. The correlations among GGB numbers, the portal vein diameter, the SI, the platelet count, and the platelet count/spleen diameter ratio were analyzed. RESULTS: The GGB detection rate and the detected GGB number by using SWI were significantly greater than those by using T1-, T2-, and T2*-weighted images. The number of GGBs in the SWI images correlated positively with the portal vein diameter and SI and correlated negatively with the platelet count and platelet count/spleen diameter ratio. CONCLUSION: SWI provided more accurate information of GGBs in patients with PH. The number of GGB may be a non-invasive predictor of improving the selection for endoscopic screening of PH patients at risk of EV.

  9. Imaging fast calcium currents beyond the limitations of electrode techniques.

    Science.gov (United States)

    Jaafari, Nadia; De Waard, Michel; Canepari, Marco

    2014-09-16

    The current understanding of Ca(2+) channel function is derived from the use of the patch-clamp technique. In particular, the measurement of fast cellular Ca(2+) currents is routinely achieved using whole-cell voltage-clamp recordings. However, this experimental approach is not applicable to the study of local native Ca(2+) channels during physiological changes of membrane potential in complex cells, since the voltage-clamp configuration constrains the membrane potential to a given value. Here, we report for the first time to our knowledge that Ca(2+) currents from individual cells can be quantitatively measured beyond the limitations of the voltage-clamp approach using fast Ca(2+) imaging with low-affinity indicators. The optical measurement of the Ca(2+) current was correlated with the membrane potential, simultaneously measured with a voltage-sensitive dye to investigate the activation of Ca(2+) channels along the apical dendrite of the CA1 hippocampal pyramidal neuron during the back-propagation of an action potential. To validate the method, we analyzed the voltage dependence of high- and low-voltage-gated Ca(2+) channels. In particular, we measured the Ca(2+) current component mediated by T-type channels, and we investigated the mechanisms of recovery from inactivation of these channels. This method is expected to become a reference approach to investigate Ca(2+) channels in their native physiological environment.

  10. Magnetic particle imaging: current developments and future directions

    Directory of Open Access Journals (Sweden)

    Panagiotopoulos N

    2015-04-01

    Full Text Available Nikolaos Panagiotopoulos,1 Robert L Duschka,1 Mandy Ahlborg,2 Gael Bringout,2 Christina Debbeler,2 Matthias Graeser,2 Christian Kaethner,2 Kerstin Lüdtke-Buzug,2 Hanne Medimagh,2 Jan Stelzner,2 Thorsten M Buzug,2 Jörg Barkhausen,1 Florian M Vogt,1 Julian Haegele1 1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig Holstein, Campus Lübeck, 2Institute of Medical Engineering, University of Lübeck, Lübeck, Germany Abstract: Magnetic particle imaging (MPI is a novel imaging method that was first proposed by Gleich and Weizenecker in 2005. Applying static and dynamic magnetic fields, MPI exploits the unique characteristics of superparamagnetic iron oxide nanoparticles (SPIONs. The SPIONs’ response allows a three-dimensional visualization of their distribution in space with a superb contrast, a very high temporal and good spatial resolution. Essentially, it is the SPIONs’ superparamagnetic characteristics, the fact that they are magnetically saturable, and the harmonic composition of the SPIONs’ response that make MPI possible at all. As SPIONs are the essential element of MPI, the development of customized nanoparticles is pursued with the greatest effort by many groups. Their objective is the creation of a SPION or a conglomerate of particles that will feature a much higher MPI performance than nanoparticles currently available commercially. A particle’s MPI performance and suitability is characterized by parameters such as the strength of its MPI signal, its biocompatibility, or its pharmacokinetics. Some of the most important adjuster bolts to tune them are the particles’ iron core and hydrodynamic diameter, their anisotropy, the composition of the particles’ suspension, and their coating. As a three-dimensional, real-time imaging modality that is free of ionizing radiation, MPI appears ideally suited for applications such as vascular imaging and interventions as well as cellular and targeted imaging. A number

  11. Image Currents in Azimuthally Inhomogeneous Metallic Beam Pipes

    CERN Document Server

    Caspers, Friedhelm; Palumbo, L; Ruggiero, F

    2001-01-01

    We consider an ultra-relativistic particle travelling on-axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. A semi-analytical solution, obtained by applying approximate boundary conditions, predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. We discuss numerical simulations and bench measurements which confirm the theoretical predictions. Implications for the beam-induced ohmic losses in the copper coated, welded LHC beam screen are also addressed.

  12. Image currents in azimuthally inhomogeneous metallic beam pipes

    Directory of Open Access Journals (Sweden)

    A. Mostacci

    2005-08-01

    Full Text Available We consider an ultrarelativistic particle traveling on axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. For a circular geometry, a semianalytical solution is obtained using the Green functions and applying approximate boundary conditions for conductors. The theory predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. Numerical electromagnetic simulations and bench measurements confirm the theoretical predictions. Implications for the beam-induced heating in the copper-coated, welded LHC beam screen are also addressed.

  13. Establishment of rules for interpreting ultraviolet autofluorescence microscopy images for noninvasive detection of Barrett's esophagus and dysplasia

    Science.gov (United States)

    Lin, Bevin; Urayama, Shiro; Saroufeem, Ramez M. G.; Matthews, Dennis L.; Demos, Stavros G.

    2012-01-01

    The diagnostic potential of autofluorescence (AF) microscopy under ultraviolet (UV) excitation is explored using ex vivo human specimens. The aim is to establish optical patterns (the rules for interpretation) that correspond to normal and abnormal histologies of the esophagus, spanning from early benign modifications (Barrett's esophagus) to subsequent dysplastic change and progression toward carcinoma. This was achieved by developing an image library categorized by disease progression. We considered morphological changes of disease as they are compared with histological diagnosis of the pathological specimen, as well as control samples of normal esophagus, proximal stomach, and small intestine tissue. Our experimental results indicate that UV AF microscopy could provide real-time histological information for visualizing changes in tissue microstructure that are currently undetectable using conventional endoscopic methods.

  14. Evaluation and Immunohistochemical Qualification of Carbogen-Induced ΔR{sub 2}* as a Noninvasive Imaging Biomarker of Improved Tumor Oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Lauren C.J., E-mail: lauren.baker@icr.ac.uk [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Boult, Jessica K.R.; Jamin, Yann; Gilmour, Lesley D.; Walker-Samuel, Simon; Burrell, Jake S. [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Ashcroft, Margaret [Division of Medicine, Centre for Cell Signalling and Molecular Genetics, University College London, London (United Kingdom); Howe, Franklyn A. [St. George' s, University of London, London (United Kingdom); Griffiths, John R. [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Raleigh, James A. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Kogel, Albert J. van der [University of Nijmegen Medical Centre, Nijmegen (Netherlands); Robinson, Simon P. [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom)

    2013-09-01

    Purpose: To evaluate and histologically qualify carbogen-induced ΔR{sub 2}* as a noninvasive magnetic resonance imaging biomarker of improved tumor oxygenation using a double 2-nitroimidazole hypoxia marker approach. Methods and Materials: Multigradient echo images were acquired from mice bearing GH3 prolactinomas, preadministered with the hypoxia marker CCI-103F, to quantify tumor R{sub 2}* during air breathing. With the mouse remaining positioned within the magnet bore, the gas supply was switched to carbogen (95% O{sub 2}, 5% CO{sub 2}), during which a second hypoxia marker, pimonidazole, was administered via an intraperitoneal line, and an additional set of identical multigradient echo images acquired to quantify any changes in tumor R{sub 2}*. Hypoxic fraction was quantified histologically using immunofluorescence detection of CCI-103F and pimonidazole adduct formation from the same whole tumor section. Carbogen-induced changes in tumor pO{sub 2} were further validated using the Oxylite fiberoptic probe. Results: Carbogen challenge significantly reduced mean tumor R{sub 2}* from 116 ± 13 s{sup −1} to 97 ± 9 s{sup −1} (P<.05). This was associated with a significantly lower pimonidazole adduct area (2.3 ± 1%), compared with CCI-103F (6.3 ± 2%) (P<.05). A significant correlation was observed between ΔR{sub 2}* and Δhypoxic fraction (r=0.55, P<.01). Mean tumor pO{sub 2} during carbogen breathing significantly increased from 6.3 ± 2.2 mm Hg to 36.0 ± 7.5 mm Hg (P<.01). Conclusions: The combined use of intrinsic susceptibility magnetic resonance imaging with a double hypoxia marker approach corroborates carbogen-induced ΔR{sub 2}* as a noninvasive imaging biomarker of increased tumor oxygenation.

  15. Are novel non-invasive imaging techniques needed in patients with suspected prosthetic heart valve endocarditis? A systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Habets, Jesse; Mali, Willem P.T.M. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Tanis, Wilco [Haga Teaching Hospital, Department of Cardiology, The Hague (Netherlands); Reitsma, Johannes B. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Brink, Renee B.A. van den [Academic Medical Center, Department of Cardiology, Amsterdam (Netherlands); Chamuleau, Steven A.J. [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Budde, Ricardo P.J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2015-07-15

    Multimodal non-invasive imaging plays a key role in establishing a diagnosis of PHV endocarditis. The objective of this study was to provide a systematic review of the literature and meta-analysis of the diagnostic accuracy of TTE, TEE, and MDCT in patients with (suspected) PHV endocarditis. Studies published between 1985 and 2013 were identified via search and cross-reference of PubMed/Embase databases. Studies were included if (1) they reported on the non-invasive index tests TTE, TEE, or MDCT; (2) data was provided on PHV endocarditis as the condition of interest; and (3) imaging results were verified against either surgical inspection/autopsy or clinical follow-up reference standards, thereby enabling the extraction of 2-by-2 tables. Twenty articles (including 496 patients) met the inclusion criteria for PHV endocarditis. TTE, TEE, and MDCT + TEE had a pooled sensitivity/specificity for vegetations of 29/100 %; 82/95 %, and 88/94 %, respectively. The pooled sensitivity/specificity of TTE, TEE, and MDCT + TEE for periannular complications was 36/93 %, 86/98 %, and 100/94 %, respectively. TEE showed good sensitivity and specificity for establishing a diagnosis of PHV endocarditis. Although MDCT data are limited, this review showed that MDCT in addition to TEE may improve sensitivity in detecting life-threatening periannular complications. (orig.)

  16. Cardiac activation mapping using ultrasound current source density imaging (UCSDI).

    Science.gov (United States)

    Olafsson, Ragnar; Witte, Russell S; Jia, Congxian; Huang, Sheng-Wen; Kim, Kang; O'Donnell, Matthew

    2009-03-01

    We describe the first mapping of biological current in a live heart using ultrasound current source density imaging (UCSDI). Ablation procedures that treat severe heart arrhythmias require detailed maps of the cardiac activation wave. The conventional procedure is time-consuming and limited by its poor spatial resolution (5-10 mm). UCSDI can potentially improve on existing mapping procedures. It is based on a pressure-induced change in resistivity known as the acousto-electric (AE) effect, which is spatially confined to the ultrasound focus. Data from 2 experiments are presented. A 540 kHz ultrasonic transducer (f/# = 1, focal length = 90 mm, pulse repetition frequency = 1600 Hz) was scanned over an isolated rabbit heart perfused with an excitation-contraction decoupler to reduce motion significantly while retaining electric function. Tungsten electrodes inserted in the left ventricle recorded simultaneously the AE signal and the low-frequency electrocardiogram (ECG). UCSDI displayed spatial and temporal patterns consistent with the spreading activation wave. The propagation velocity estimated from UCSDI was 0.25 +/- 0.05 mm/ms, comparable to the values obtained with the ECG signals. The maximum AE signal-to-noise ratio after filtering was 18 dB, with an equivalent detection threshold of 0.1 mA/ cm(2). This study demonstrates that UCSDI is a potentially powerful technique for mapping current flow and biopotentials in the heart.

  17. Sensitivity improvement of one-shot Fourier spectroscopic imager for realization of noninvasive blood glucose sensors in smartphones

    Science.gov (United States)

    Kawashima, Natsumi; Nogo, Kosuke; Hosono, Satsuki; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

    2016-11-01

    The use of the wide-field-stop and beam-expansion method for sensitivity enhancement of one-shot Fourier spectroscopy is proposed to realize health care sensors installed in smartphones for daily monitoring. When measuring the spectral components of human bodies noninvasively, diffuse reflected light from biological membranes is too weak for detection using conventional hyperspectral cameras. One-shot Fourier spectroscopy is a spatial phase-shift-type interferometer that can determine the one-dimensional spectral characteristics from a single frame. However, this method has low sensitivity, so that only the spectral characteristics of light sources with direct illumination can be obtained, because a single slit is used as a field stop. The sensitivity of the proposed spectroscopic method is improved by using the wide-field-stop and beam-expansion method. The use of a wider field stop slit width increases the detected light intensity; however, this simultaneously narrows the diffraction angle. The narrower collimated objective beam diameter degrades the visibility of interferograms. Therefore, a plane-concave cylindrical lens between the objective plane and the single slit is introduced to expand the beam diameter. The resulting sensitivity improvement achieved when using the wide-field-stop and beam-expansion method allows the spectral characteristics of hemoglobin to be obtained noninvasively from a human palm using a midget lamp.

  18. Non-invasive assessment of elastic modulus of arterial constructs during cell culture using ultrasound elasticity imaging.

    Science.gov (United States)

    Dutta, Debaditya; Lee, Kee-Won; Allen, Robert A; Wang, Yadong; Brigham, John C; Kim, Kang

    2013-11-01

    Mechanical strength is a key design factor in tissue engineering of arteries. Most existing techniques assess the mechanical property of arterial constructs destructively, leading to sacrifice of a large number of animals. We propose an ultrasound-based non-invasive technique for the assessment of the mechanical strength of engineered arterial constructs. Tubular scaffolds made from a biodegradable elastomer and seeded with vascular fibroblasts and smooth muscle cells were cultured in a pulsatile-flow bioreactor. Scaffold distension was computed from ultrasound radiofrequency signals of the pulsating scaffold via 2-D phase-sensitive speckle tracking. Young's modulus was then calculated by solving the inverse problem from the distension and the recorded pulse pressure. The stiffness thus computed from ultrasound correlated well with direct mechanical testing results. As the scaffolds matured in culture, ultrasound measurements indicated an increase in Young's modulus, and histology confirmed the growth of cells and collagen fibrils in the constructs. The results indicate that ultrasound elastography can be used to assess and monitor non-invasively the mechanical properties of arterial constructs. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. Current status of PET imaging in Huntington's disease.

    Science.gov (United States)

    Pagano, Gennaro; Niccolini, Flavia; Politis, Marios

    2016-06-01

    To review the developments of recent decades and the current status of PET molecular imaging in Huntington's disease (HD). A systematic review of PET studies in HD was performed. The MEDLINE, Web of Science, Cochrane and Scopus databases were searched for articles in all languages published up to 19 August 2015 using the major medical subject heading "Huntington Disease" combined with text and key words "Huntington Disease", "Neuroimaging" and "PET". Only peer-reviewed, primary research studies in HD patients and premanifest HD carriers, and studies in which clinical features were described in association with PET neuroimaging results, were included in this review. Reviews, case reports and nonhuman studies were excluded. A total of 54 PET studies were identified and analysed in this review. Brain metabolism ([(18)F]FDG and [(15)O]H2O), presynaptic ([(18)F]fluorodopa, [(11)C]β-CIT and [(11)C]DTBZ) and postsynaptic ([(11)C]SCH22390, [(11)C]FLB457 and [(11)C]raclopride) dopaminergic function, phosphodiesterases ([(18)F]JNJ42259152, [(18)F]MNI-659 and [(11)C]IMA107), and adenosine ([(18)F]CPFPX), cannabinoid ([(18)F]MK-9470), opioid ([(11)C]diprenorphine) and GABA ([(11)C]flumazenil) receptors were evaluated as potential biomarkers for monitoring disease progression and for assessing the development and efficacy of novel disease-modifying drugs in premanifest HD carriers and HD patients. PET studies evaluating brain restoration and neuroprotection were also identified and described in detail. Brain metabolism, postsynaptic dopaminergic function and phosphodiesterase 10A levels were proven to be powerful in assessing disease progression. However, no single technique may be currently considered an optimal biomarker and an integrative multimodal imaging approach combining different techniques should be developed for monitoring potential neuroprotective and preventive treatment in HD.

  20. Mapping the ECG in the live rabbit heart using Ultrasound Current Source Density Imaging with coded excitation.

    Science.gov (United States)

    Qin, Yexian; Li, Qian; Ingram, Pier; Witte, Russell S

    2012-10-01

    Ultrasound current source density imaging (UCSDI) is a noninvasive technique for mapping electric current fields in 4D (space + time) with the resolution of ultrasound imaging. This approach can potentially overcome limitations of conventional electrical mapping procedures often used during treatment of cardiac arrhythmia or epilepsy. However, at physiologic currents, the detected acoustoelectric (AE) interaction signal in tissue is very weak. In this work, we evaluated coded ultrasound excitation (chirps) for improving the sensitivity of UCSDI for mapping the electrocardiogram (ECG) in a live rabbit heart preparation. Results confirmed that chirps improved detection of the AE signal by as much as 6.1 dB compared to a square pulse. We further demonstrated mapping the ECG using a clinical intracardiac catheter, 1 MHz ultrasound transducer and coded excitation. B-mode pulse echo and UCSDI revealed regions of high current flow in the heart wall during the peak of the ECG. These improvements to UCSDI are important steps towards translation of this new technology to the clinic for rapidly mapping the cardiac activation wave.

  1. 18F and 18FDG PET imaging of osteosarcoma to non-invasively monitor in situ changes in cellular proliferation and bone differentiation upon MYC inactivation

    Science.gov (United States)

    Arvanitis, Constadina; Bendapudi, Pavan K.; Tseng, Jeffrey R.; Gambhir, Sanjiv Sam; Felsher, Dean W.

    2014-01-01

    Osteosarcoma is one of the most common pediatric cancers. Accurate imaging of osteosarcoma is important for proper clinical staging of the disease and monitoring of the tumor’s response to therapy. The MYC oncogene has been commonly implicated in the pathogenesis of human osteosarcoma. Previously, we have described a conditional transgenic mouse model of MYC-induced osteosarcoma. These tumors are highly invasive and are frequently associated with pulmonary metastases. In our model, upon MYC inactivation osteosarcomas lose their neoplastic properties, undergo proliferative arrest, and differentiate into mature bone. We reasoned that we could use our model system to develop noninvasive imaging modalities to interrogate the consequences of MYC inactivation on tumor cell biology in situ. We performed positron emission tomography (PET) combining the use of both 18F-fluorodeoxyglucose (18FDG) and 18F-flouride (18F) to detect metabolic activity and bone mineralization/remodeling. We found that upon MYC inactivation, tumors exhibited a slight reduction in uptake of 18FDG and a significant increase in the uptake of 18F along with associated histological changes. Thus, these cells have apparently lost their neoplastic properties based upon both examination of their histology and biologic activity. However, these tumors continue to accumulate 18FDG at levels significantly elevated compared to normal bone. Therefore, PET can be used to distinguish normal bone cells from tumors that have undergone differentiation upon oncogene inactivation. In addition, we found that 18F is a highly sensitive tracer for detection of pulmonary metastasis. Collectively, we conclude that combined modality PET/CT imaging incorporating both 18FDG and 18F is a highly sensitive means to non-invasively measure osteosarcoma growth and the therapeutic response, as well as to detect tumor cells that have undergone differentiation upon oncogene inactivation. PMID:18981708

  2. (18)F and (18)FDG PET imaging of osteosarcoma to non-invasively monitor in situ changes in cellular proliferation and bone differentiation upon MYC inactivation.

    Science.gov (United States)

    Arvanitis, Constadina; Bendapudi, Pavan K; Tseng, Jeffrey R; Gambhir, Sanjiv Sam; Felsher, Dean W

    2008-12-01

    Osteosarcoma is one of the most common pediatric cancers. Accurate imaging of osteosarcoma is important for proper clinical staging of the disease and monitoring of the tumor's response to therapy. The MYC oncogene has been commonly implicated in the pathogenesis of human osteosarcoma. Previously, we have described a conditional transgenic mouse model of MYC-induced osteosarcoma. These tumors are highly invasive and are frequently associated with pulmonary metastases. In our model, upon MYC inactivation osteosarcomas lose their neoplastic properties, undergo proliferative arrest and differentiate into mature bone. We reasoned that we could use our model system to develop noninvasive imaging modalities to interrogate the consequences of MYC inactivation on tumor cell biology in situ. We performed positron emission tomography (PET) combining the use of both (18)F-fluorodeoxyglucose ((18)FDG) and (18)F-flouride ((18)F) to detect metabolic activity and bone mineralization/remodeling. We found that upon MYC inactivation, tumors exhibited a slight reduction in uptake of (18)FDG and a significant increase in the uptake of (18)F along with associated histological changes. Thus, these cells have apparently lost their neoplastic properties based upon both examination of their histology and biologic activity. However, these tumors continue to accumulate (18)FDG at levels significantly elevated compared to normal bone. Therefore, PET can be used to distinguish normal bone cells from tumors that have undergone differentiation upon oncogene inactivation. In addition, we found that (18)F is a highly sensitive tracer for detection of pulmonary metastasis. Collectively, we conclude that combined modality PET/CT imaging incorporating both (18)FDG and (18)F is a highly sensitive means to non-invasively measure osteosarcoma growth and the therapeutic response, as well as to detect tumor cells that have undergone differentiation upon oncogene inactivation.

  3. Magnetostatic image current and its application to an analytic identification of a current dipole inside a conducting sphere.

    Science.gov (United States)

    He, S; Norgren, M

    2000-02-01

    The image solution for the static magnetic field outside a conducting sphere with an internal current dipole is considered. The image current, which is a linear distribution of magnetic dipoles on the line segment between the dipole point and the center of the sphere, is derived by using the fact that the induced current does not have any contribution to the radial component of the magnetic field outside the sphere. The image is then used to obtain some explicit formulas for identifying the location and tangential moment of the primary current dipole. This explicit identification method is also tested with a real model for a patient's brain.

  4. Multiparametric magnetic resonance imaging of the prostate: current concepts.

    NARCIS (Netherlands)

    Bittencourt, L.K.; Hausmann, D.; Sabaneeff, N.; Gasparetto, E.L.; Barentsz, J.O.

    2014-01-01

    Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI).

  5. Multiparametric magnetic resonance imaging of the prostate: current concepts.

    NARCIS (Netherlands)

    Bittencourt, L.K.; Hausmann, D.; Sabaneeff, N.; Gasparetto, E.L.; Barentsz, J.O.

    2014-01-01

    Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI).

  6. Superparamagnetic iron oxide nanoparticles function as a long-term, multi-modal imaging label for non-invasive tracking of implanted progenitor cells.

    Directory of Open Access Journals (Sweden)

    Christina A Pacak

    Full Text Available The purpose of this study was to determine the ability of superparamagnetic iron oxide (SPIO nanoparticles to function as a long-term tracking label for multi-modal imaging of implanted engineered tissues containing muscle-derived progenitor cells using magnetic resonance imaging (MRI and X-ray micro-computed tomography (μCT. SPIO-labeled primary myoblasts were embedded in fibrin sealant and imaged to obtain intensity data by MRI or radio-opacity information by μCT. Each imaging modality displayed a detection gradient that matched increasing SPIO concentrations. Labeled cells were then incorporated in fibrin sealant, injected into the atrioventricular groove of rat hearts, and imaged in vivo and ex vivo for up to 1 year. Transplanted cells were identified in intact animals and isolated hearts using both imaging modalities. MRI was better able to detect minuscule amounts of SPIO nanoparticles, while μCT more precisely identified the location of heavily-labeled cells. Histological analyses confirmed that iron oxide particles were confined to viable, skeletal muscle-derived cells in the implant at the expected location based on MRI and μCT. These analyses showed no evidence of phagocytosis of labeled cells by macrophages or release of nanoparticles from transplanted cells. In conclusion, we established that SPIO nanoparticles function as a sensitive and specific long-term label for MRI and μCT, respectively. Our findings will enable investigators interested in regenerative therapies to non-invasively and serially acquire complementary, high-resolution images of transplanted cells for one year using a single label.

  7. Superparamagnetic iron oxide nanoparticles function as a long-term, multi-modal imaging label for non-invasive tracking of implanted progenitor cells.

    Science.gov (United States)

    Pacak, Christina A; Hammer, Peter E; MacKay, Allison A; Dowd, Rory P; Wang, Kai-Roy; Masuzawa, Akihiro; Sill, Bjoern; McCully, James D; Cowan, Douglas B

    2014-01-01

    The purpose of this study was to determine the ability of superparamagnetic iron oxide (SPIO) nanoparticles to function as a long-term tracking label for multi-modal imaging of implanted engineered tissues containing muscle-derived progenitor cells using magnetic resonance imaging (MRI) and X-ray micro-computed tomography (μCT). SPIO-labeled primary myoblasts were embedded in fibrin sealant and imaged to obtain intensity data by MRI or radio-opacity information by μCT. Each imaging modality displayed a detection gradient that matched increasing SPIO concentrations. Labeled cells were then incorporated in fibrin sealant, injected into the atrioventricular groove of rat hearts, and imaged in vivo and ex vivo for up to 1 year. Transplanted cells were identified in intact animals and isolated hearts using both imaging modalities. MRI was better able to detect minuscule amounts of SPIO nanoparticles, while μCT more precisely identified the location of heavily-labeled cells. Histological analyses confirmed that iron oxide particles were confined to viable, skeletal muscle-derived cells in the implant at the expected location based on MRI and μCT. These analyses showed no evidence of phagocytosis of labeled cells by macrophages or release of nanoparticles from transplanted cells. In conclusion, we established that SPIO nanoparticles function as a sensitive and specific long-term label for MRI and μCT, respectively. Our findings will enable investigators interested in regenerative therapies to non-invasively and serially acquire complementary, high-resolution images of transplanted cells for one year using a single label.

  8. Multimodality imaging for patient evaluation and guidance of catheter ablation for atrial fibrillation - current status and future perspective.

    Science.gov (United States)

    Bhagirath, P; van der Graaf, A W M; Karim, R; van Driel, V J H M; Ramanna, H; Rhode, K S; de Groot, N M S; Götte, M J W

    2014-08-20

    Left atrial catheter ablation is an established non-pharmacological therapy for the treatment of atrial fibrillation. The importance of a noninvasive multimodality imaging approach is emphasized by the current guidelines for the various phases of the ablation work-up e.g. patient identification, therapy guidance and procedural evaluation. Advances in the capabilities of imaging modalities and the increasing cost of healthcare warrant a review of the multimodality approach. This review discusses the application of cardiac imaging for pulmonary vein and left atrial ablation divided into stages: pre-procedural stage (assessment of left atrial dimensions, left atrial appendage thrombus and pulmonary vein anatomy), peri-procedural stage (integration of anatomical and electrical information) and post-procedural stage (evaluation of efficacy by assessment of tissue properties). Each section is dedicated to one of the subtopics of a stage, allowing a thorough comparison to be made between the strengths and weaknesses of the different imaging modalities and the identification of one that exhibits the potential for a single technique approach.

  9. Belowground plant development measured with magnetic resonance imaging (MRI: exploiting the potential for non-invasive trait quantification using sugar beet as a proxy

    Directory of Open Access Journals (Sweden)

    Ralf eMetzner

    2014-09-01

    Full Text Available Both structural and functional properties of belowground plant organs are critical for the development and yield of plants but, compared to the shoot, much more difficult to observe due to soil opacity. Many processes concerning the belowground plant performance are not fully understood, in particular spatial and temporal dynamics and their interrelation with environmental factors. We used Magnetic Resonance Imaging (MRI as a noninvasive method to evaluate which traits can be measured when a complex plant organ is monitored in-vivo while growing in the soil. We chose sugar beet (Beta vulgaris ssp. vulgaris as a model system. The beet consists mainly of root tissues, is rather complex regarding tissue structure and responses to environmental factors, and thereby a good object to test the applicability of MRI for 3D phenotyping approaches. Over a time period of up to 3 months, traits such as beet morphology or anatomy were followed in the soil and the effect of differently sized pots on beet fresh weight calculated from MRI data was studied. There was a clear positive correlation between the pot size and the increase in fresh weight of a sugar beet over time. Since knowledge of the development of internal beet structures with several concentric cambia, vascular and parenchyma rings is still limited, we consecutively acquired 3D volumetric images on individual plants using the MRI contrast parameter T2 to map the development of rings at the tissue level. This demonstrates that MRI provides versatile protocols to non-invasively measure plant traits in the soil. It opens new avenues to investigate belowground plant performance under adverse environmental conditions such as drought, nutrient shortage or soil compaction to seek for traits of belowground organs making plants more resilient to stress.

  10. Belowground plant development measured with magnetic resonance imaging (MRI): exploiting the potential for non-invasive trait quantification using sugar beet as a proxy

    Science.gov (United States)

    Metzner, Ralf; van Dusschoten, Dagmar; Bühler, Jonas; Schurr, Ulrich; Jahnke, Siegfried

    2014-01-01

    Both structural and functional properties of belowground plant organs are critical for the development and yield of plants but, compared to the shoot, much more difficult to observe due to soil opacity. Many processes concerning the belowground plant performance are not fully understood, in particular spatial and temporal dynamics and their interrelation with environmental factors. We used Magnetic Resonance Imaging (MRI) as a noninvasive method to evaluate which traits can be measured when a complex plant organ is monitored in-vivo while growing in the soil. We chose sugar beet (Beta vulgaris ssp. vulgaris) as a model system. The beet consists mainly of root tissues, is rather complex regarding tissue structure and responses to environmental factors, and thereby a good object to test the applicability of MRI for 3D phenotyping approaches. Over a time period of up to 3 months, traits such as beet morphology or anatomy were followed in the soil and the effect of differently sized pots on beet fresh weight calculated from MRI data was studied. There was a clear positive correlation between the pot size and the increase in fresh weight of a sugar beet over time. Since knowledge of the development of internal beet structures with several concentric cambia, vascular and parenchyma rings is still limited, we consecutively acquired 3D volumetric images on individual plants using the MRI contrast parameter T2 to map the development of rings at the tissue level. This demonstrates that MRI provides versatile protocols to non-invasively measure plant traits in the soil. It opens new avenues to investigate belowground plant performance under adverse environmental conditions such as drought, nutrient shortage, or soil compaction to seek for traits of belowground organs making plants more resilient to stress. PMID:25278947

  11. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2015-01-01

    Full Text Available Coronary CT angiography (CCTA has become an important noninvasive imaging modality in the diagnosis of coronary artery disease (CAD. CCTA enables accurate evaluation of coronary artery stenosis. However, CCTA provides limited information on the physiological significance of stenotic lesions. A noninvasive “one-stop-shop” diagnostic test that can provide both anatomical significance and functional significance of stenotic lesions would be beneficial in the diagnosis and management of CAD. Recently, with the introduction of novel techniques, such as myocardial CT perfusion, CT-derived fractional flow reserve (FFRCT, and transluminal attenuation gradient (TAG, CCTA has emerged as a noninvasive method for the assessment of both anatomy of coronary lesions and its physiological consequences during a single study. This review provides an overview of the current status of new CT techniques for the physiologic assessments of CAD.

  12. Current Status of Imaging Physics and Instrumentation In Nuclear Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Joung [Institute of Health Science, Yonsei University, Seoul (Korea, Republic of)

    2008-04-15

    Diagnostic and functional imaging device have been developed independently. The recognition that combining of these two devices can provide better diagnostic outcomes by fusing anatomical and functional images. The representative examples of combining devices would be PET/CT and SPECT/CT. Development and their applications of animal imaging and instrumentation have been very active, as new drug development with advanced imaging device has been increased. The development of advanced imaging device resulted in researching and developing for detector technology and imaging systems. It also contributed to develop a new software, reconstruction algorithm, correction methods for physical factors, image quantitation, computer simulation, kinetic modeling, dosimetry, and correction for motion artifacts. Recently, development of MRI and PET by combining them together was reported. True integration of MRI and PET has been making the progress and their results were reported. The recent status of imaging and instrumentation in nuclear medicine is reported in this paper.

  13. Current cardiac imaging techniques for detection of left ventricular mass

    Directory of Open Access Journals (Sweden)

    Celebi Aksuyek S

    2010-06-01

    Full Text Available Abstract Estimation of left ventricular (LV mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR and cardiovascular computed tomography (CCT are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.

  14. The current progress of the ALICE Ring Imaging Cherenkov Detector

    CERN Document Server

    Braem, André; Davenport, M; Mauro, A D; Franco, A; Gallas, A; Hoedlmoser, H; Martinengo, P; Nappi, E; Paic, G; Piuz, François; Peskov, Vladimir

    2007-01-01

    Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface. Finally we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy ions collisions, hadrons up to 30 GeV/c.

  15. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography: design and implementation of the CORE320 multicenter, multinational diagnostic study.

    Science.gov (United States)

    Vavere, Andrea L; Simon, Gregory G; George, Richard T; Rochitte, Carlos E; Arai, Andrew E; Miller, Julie M; Di Carli, Marcello; Arbab-Zadeh, Armin; Zadeh, Armin A; Dewey, Marc; Niinuma, Hiroyuki; Laham, Roger; Rybicki, Frank J; Schuijf, Joanne D; Paul, Narinder; Hoe, John; Kuribyashi, Sachio; Sakuma, Hajime; Nomura, Cesar; Yaw, Tan Swee; Kofoed, Klaus F; Yoshioka, Kunihiro; Clouse, Melvin E; Brinker, Jeffrey; Cox, Christopher; Lima, Joao A C

    2011-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8 countries worldwide. CT has the potential to assess both anatomy and physiology in a single imaging session. The co-primary aim of the CORE320 study is to define the per-patient diagnostic accuracy of the combination of coronary CTA and myocardial CTP to detect physiologically significant coronary artery disease compared with (1) the combination of conventional coronary angiography and SPECT-MPI and (2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD.

  16. The role of indium-111 antimyosin (Fab) imaging as a noninvasive surveillance method of human heart transplant rejection

    Energy Technology Data Exchange (ETDEWEB)

    De Nardo, D.; Scibilia, G.; Macchiarelli, A.G.; Cassisi, A.; Tonelli, E.; Papalia, U.; Gallo, P.; Antolini, M.; Pitucco, G.; Reale, A. (Universita degli Studi di Roma I La Sapienza Policlinico Umberto I (Italy))

    1989-09-01

    The identification of rejection after heart transplantation in patients receiving cyclosporine immunosuppressive therapy requires the endomyocardial biopsy, an invasive method associated with a finite morbidity. To evaluate the role of indium-111 antimyosin (Fab) scintigraphy as a noninvasive surveillance method of heart transplant rejection, the Fab fragment of murine monoclonal antimyosin antibodies labeled with indium-111 was administered intravenously in 30 scintigraphic studies to 10 consecutive heart transplant recipients. Endomyocardial biopsy specimens were obtained 72 hours after each scintigraphic study. Nineteen scintigraphic studies had negative findings; no false negative finding was obtained. Eleven antimyosin scintigraphic studies had positive findings, and in these studies endomyocardial biopsy revealed mild rejection in two cases, moderate acute rejection with myocyte necrosis in two cases, myocyte necrosis as a consequence of ischemic injury in six cases, and possibly cytotoxic damage in one case. Antimyosin scintigraphy may represent a reliable screening method for the surveillance of heart transplant patients. In the presence of a negative finding from antimyosin scintigraphy, it may be possible to avoid endomyocardial biopsy. Conversely, in patients who have a positive finding from antimyosin scintigraphy, the endomyocardial biopsy is mandatory to establish the definitive diagnosis by histologic examination of the myocardium.

  17. Non-invasive imaging of infection after treatment with tumor-homing bacteria using chemical exchange saturation transfer (CEST) MRI

    Science.gov (United States)

    Liu, Guanshu; Bettegowda, Chetan; Qiao, Yuan; Staedtke, Verena; Chan, Kannie W.Y.; Bai, Renyuan; Li, Yuguo; Riggins, Gregory J.; Kinzler, Kenneth W.; Bulte, Jeff W.M.; McMahon, Michael T.; Gilad, Assaf A.; Vogelstein, Bert; Zhou, Shibin; van Zijl, Peter C.M.

    2013-01-01

    Purpose To develop a non-invasive MRI method for determining the germination and infection of tumor-homing bacteria in bacteriolytic cancer therapy using endogenous CEST contrast. Methods The CEST parameters of the anaerobic gram-positive bacterium Clostridium novyi-NT (C. novyi-NT) were first characterized in vitro, then used to detect C. novyi-NT germination and infection in subcutaneous CT26 colorectal tumor-bearing mice (n=6) after injection of 300 million bacterial spores. Lipopolysacharide (LPS) injected mice were used to exclude that the changes of CEST MRI were due to inflammation. Results CEST contrast was observed over a broad frequency range for bacterial suspensions in vitro, with the maximum contrast around 2.6 ppm from the water resonance. No signal could be detected for bacterial spores, demonstrating the specificity for germination. In vivo, a significant elevation of CEST contrast was identified in C. novyi-NT infected tumors as compared to those before bacterial germination and infection (p 0.05, n=4). Conclusions Endogenous bacterial CEST contrast (bacCEST) can be used to monitor the germination and proliferation of the therapeutic bacterium C. novyi-NT without a need for exogenous cell labeling probes. PMID:24123389

  18. Current challenges and future directions in cardiac imaging.

    Science.gov (United States)

    Wann, Samuel; Tunio, Javed

    2010-07-01

    Imaging is one of the most important accomplishments of medicine during the last 1000 years. The contribution of modern imaging to progress in the delivery of health care is unquestioned. However, we need to refine our use of imaging, limiting its use to those occasions when it can contribute directly or indirectly to improving and lengthening the lives of patients. Technology prowess in imaging alone is not sufficient to deliver value to individuals or to society. Continued investment in imaging technology requires critical appraisal of its use in clinical decision making and patient outcomes.

  19. SU-E-J-96: Multi-Axis Dose Accumulation of Noninvasive Image-Guided Breast Brachytherapy Through Biomechanical Modeling of Tissue Deformation Using the Finite Element Method

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States); Ghadyani, HR [SUNY Farmingdale State College, Farmingdale, NY (United States); Bastien, AD; Lutz, NN [Univeristy Massachusetts Lowell, Lowell, MA (United States); Hepel, JT [Rhode Island Hospital, Providence, RI (United States)

    2015-06-15

    Purpose: Noninvasive image-guided breast brachytherapy delivers conformal HDR Ir-192 brachytherapy treatments with the breast compressed, and treated in the cranial-caudal and medial-lateral directions. This technique subjects breast tissue to extreme deformations not observed for other disease sites. Given that, commercially-available software for deformable image registration cannot accurately co-register image sets obtained in these two states, a finite element analysis based on a biomechanical model was developed to deform dose distributions for each compression circumstance for dose summation. Methods: The model assumed the breast was under planar stress with values of 30 kPa for Young’s modulus and 0.3 for Poisson’s ratio. Dose distributions from round and skin-dose optimized applicators in cranial-caudal and medial-lateral compressions were deformed using 0.1 cm planar resolution. Dose distributions, skin doses, and dose-volume histograms were generated. Results were examined as a function of breast thickness, applicator size, target size, and offset distance from the center. Results: Over the range of examined thicknesses, target size increased several millimeters as compression thickness decreased. This trend increased with increasing offset distances. Applicator size minimally affected target coverage, until applicator size was less than the compressed target size. In all cases, with an applicator larger or equal to the compressed target size, > 90% of the target covered by > 90% of the prescription dose. In all cases, dose coverage became less uniform as offset distance increased and average dose increased. This effect was more pronounced for smaller target-applicator combinations. Conclusions: The model exhibited skin dose trends that matched MC-generated benchmarking results and clinical measurements within 2% over a similar range of breast thicknesses and target sizes. The model provided quantitative insight on dosimetric treatment variables over

  20. Role of noninvasive testing in the clinical evaluation of women with suspected coronary artery disease: Consensus statement from the Cardiac Imaging Committee, Council on Clinical Cardiology, and the Cardiovascular Imaging and Intervention Committee, Council on Cardiovascular Radiology and Intervention, American Heart Association.

    Science.gov (United States)

    Mieres, Jennifer H; Shaw, Leslee J; Arai, Andrew; Budoff, Matthew J; Flamm, Scott D; Hundley, W Gregory; Marwick, Thomas H; Mosca, Lori; Patel, Ayan R; Quinones, Miguel A; Redberg, Rita F; Taubert, Kathryn A; Taylor, Allen J; Thomas, Gregory S; Wenger, Nanette K

    2005-02-08

    Cardiovascular disease is the leading cause of mortality for women in the United States. Coronary heart disease, which includes coronary atherosclerotic disease, myocardial infarction, acute coronary syndromes, and angina, is the largest subset of this mortality, with >240,000 women dying annually from the disease. Atherosclerotic coronary artery disease (CAD) is the focus of this consensus statement. Research continues to report underrecognition and underdiagnosis of CAD as contributory to high mortality rates in women. Timely and accurate diagnosis can significantly reduce CAD mortality for women; indeed, once the diagnosis is made, it does appear that current treatments are equally effective at reducing risk in both women and men. As such, noninvasive diagnostic and prognostic testing offers the potential to identify women at increased CAD risk as the basis for instituting preventive and therapeutic interventions. Nevertheless, the recent evidence-based practice program report from the Agency for Healthcare Research and Quality noted the paucity of women enrolled in diagnostic research studies. Consequently, much of the evidence supporting contemporary recommendations for noninvasive diagnostic studies in women is extrapolated from studies conducted predominantly in cohorts of middle-aged men. The majority of diagnostic and prognostic evidence in cardiac imaging in women and men has been derived from observational registries and referral populations that are affected by selection and other biases. Thus, a better understanding of the potential impact of sex differences on noninvasive cardiac testing in women may greatly improve clinical decision making. This consensus statement provides a synopsis of available evidence on the role of the exercise ECG and cardiac imaging modalities, both those in common use as well as developing technologies that may add clinical value to the diagnosis and risk assessment of the symptomatic and asymptomatic woman with suspected

  1. A Study on the Temperature Correlation of B-mode Ultrasonic Image Gray for Noninvasive Temperature Monitoring in Hyperthermia

    Institute of Scientific and Technical Information of China (English)

    WU Shui-cai; Ren Xin-ying; Bai Yan-ping; Zeng Yi

    2006-01-01

    This paper deals with the temperature correlation of gray scale of Bmode ultrasound image from heated tissue. In this study, many in-vitro fresh pig livers are heated in a temperature range from 28℃ to 45℃, from which a series of B-mode ultrasonic images of livers were obtained. The gray-value is evaluated from the ultrasound images respectively. A correlation of the mean gray value of the selected regions (12×12 pixels) in B-mode ultrasonic images of liver and its temperature was pointed out. And the experiment results agreed the evaluation well. And it is possible to monitor the tissue temperature changing in hyperthermia using this correlation.

  2. New concepts in molecular imaging: non-invasive MRI spotting of proteolysis using an Overhauser effect switch.

    Directory of Open Access Journals (Sweden)

    Philippe Mellet

    Full Text Available BACKGROUND: Proteolysis, involved in many processes in living organisms, is tightly regulated in space and time under physiological conditions. However deregulation can occur with local persistent proteolytic activities, e.g. in inflammation, cystic fibrosis, tumors, or pancreatitis. Furthermore, little is known about the role of many proteases, hence there is a need of new imaging methods to visualize specifically normal or disease-related proteolysis in intact bodies. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, a new concept for non invasive proteolysis imaging is proposed. Overhauser-enhanced Magnetic Resonance Imaging (OMRI at 0.2 Tesla was used to monitor the enzymatic hydrolysis of a nitroxide-labeled protein. In vitro, image intensity switched from 1 to 25 upon proteolysis due to the associated decrease in the motional correlation time of the substrate. The OMRI experimental device used in this study is consistent with protease imaging in mice at 0.2 T without significant heating. Simulations show that this enzymatic-driven OMRI signal switch can be obtained at lower frequencies suitable for larger animals or humans. CONCLUSIONS/SIGNIFICANCE: The method is highly sensitive and makes possible proteolysis imaging in three dimensions with a good spatial resolution. Any protease could be targeted specifically through the use of taylor-made cleavable macromolecules. At short term OMRI of proteolysis may be applied to basic research as well as to evaluate therapeutic treatments in small animal models of experimental diseases.

  3. Measuring elevated intracranial pressure through noninvasive methods

    DEFF Research Database (Denmark)

    Kristiansson, Helena; Nissborg, Emelie; Bartek, Jiri;

    2013-01-01

    . This article is a review of the current literature on noninvasive methods for measuring and evaluating elevated ICP. The main focus is on studies that compare noninvasively measured ICP with invasively measured ICP. The aim is to provide an overview of the current state of the most common noninvasive...... is associated with certain risks. Intraparenchymal ICP monitoring methods are considered to be a safer alternative but can, in certain conditions, be imprecise due to zero drift and still require an invasive procedure. An accurate noninvasive method to measure elevated ICP would therefore be desirable...

  4. Video-mosaicking of in vivo reflectance confocal microscopy images for noninvasive examination of skin lesion (Conference Presentation)

    Science.gov (United States)

    Kose, Kivanc; Gou, Mengran; Yelamos, Oriol; Cordova, Miguel A.; Rossi, Anthony; Nehal, Kishwer S.; Camps, Octavia I.; Dy, Jennifer G.; Brooks, Dana H.; Rajadhyaksha, Milind

    2017-02-01

    In this report we describe a computer vision based pipeline to convert in-vivo reflectance confocal microscopy (RCM) videos collected with a handheld system into large field of view (FOV) mosaics. For many applications such as imaging of hard to access lesions, intraoperative assessment of MOHS margins, or delineation of lesion margins beyond clinical borders, raster scan based mosaicing techniques have clinically significant limitations. In such cases, clinicians often capture RCM videos by freely moving a handheld microscope over the area of interest, but the resulting videos lose large-scale spatial relationships. Videomosaicking is a standard computational imaging technique to register, and stitch together consecutive frames of videos into large FOV high resolution mosaics. However, mosaicing RCM videos collected in-vivo has unique challenges: (i) tissue may deform or warp due to physical contact with the microscope objective lens, (ii) discontinuities or "jumps" between consecutive images and motion blur artifacts may occur, due to manual operation of the microscope, and (iii) optical sectioning and resolution may vary between consecutive images due to scattering and aberrations induced by changes in imaging depth and tissue morphology. We addressed these challenges by adapting or developing new algorithmic methods for videomosaicking, specifically by modeling non-rigid deformations, followed by automatically detecting discontinuities (cut locations) and, finally, applying a data-driven image stitching approach that fully preserves resolution and tissue morphologic detail without imposing arbitrary pre-defined boundaries. We will present example mosaics obtained by clinical imaging of both melanoma and non-melanoma skin cancers. The ability to combine freehand mosaicing for handheld microscopes with preserved cellular resolution will have high impact application in diverse clinical settings, including low-resource healthcare systems.

  5. Failure Analysis of CCD Image Sensors Using SQUID and GMR Magnetic Current Imaging

    Science.gov (United States)

    Felt, Frederick S.

    2005-01-01

    During electrical testing of a Full Field CCD Image Senor, electrical shorts were detected on three of six devices. These failures occurred after the parts were soldered to the PCB. Failure analysis was performed to determine the cause and locations of these failures on the devices. After removing the fiber optic faceplate, optical inspection was performed on the CCDs to understand the design and package layout. Optical inspection revealed that the device had a light shield ringing the CCD array. This structure complicated the failure analysis. Alternate methods of analysis were considered, including liquid crystal, light and thermal emission, LT/A, TT/A SQUID, and MP. Of these, SQUID and MP techniques were pursued for further analysis. Also magnetoresistive current imaging technology is discussed and compared to SQUID.

  6. Retooling Laser Speckle Contrast Analysis Algorithm to Enhance Non-Invasive High Resolution Laser Speckle Functional Imaging of Cutaneous Microcirculation

    Science.gov (United States)

    Gnyawali, Surya C.; Blum, Kevin; Pal, Durba; Ghatak, Subhadip; Khanna, Savita; Roy, Sashwati; Sen, Chandan K.

    2017-01-01

    Cutaneous microvasculopathy complicates wound healing. Functional assessment of gated individual dermal microvessels is therefore of outstanding interest. Functional performance of laser speckle contrast imaging (LSCI) systems is compromised by motion artefacts. To address such weakness, post-processing of stacked images is reported. We report the first post-processing of binary raw data from a high-resolution LSCI camera. Sharp images of low-flowing microvessels were enabled by introducing inverse variance in conjunction with speckle contrast in Matlab-based program code. Extended moving window averaging enhanced signal-to-noise ratio. Functional quantitative study of blood flow kinetics was performed on single gated microvessels using a free hand tool. Based on detection of flow in low-flow microvessels, a new sharp contrast image was derived. Thus, this work presents the first distinct image with quantitative microperfusion data from gated human foot microvasculature. This versatile platform is applicable to study a wide range of tissue systems including fine vascular network in murine brain without craniotomy as well as that in the murine dorsal skin. Importantly, the algorithm reported herein is hardware agnostic and is capable of post-processing binary raw data from any camera source to improve the sensitivity of functional flow data above and beyond standard limits of the optical system. PMID:28106129

  7. Chest trauma in children: current imaging guidelines and techniques.

    LENUS (Irish Health Repository)

    Moore, Michael A

    2011-09-01

    Given the heterogeneous nature of pediatric chest trauma, the optimal imaging approach is tailored to the specific patient. Chest radiography remains the most important imaging modality for initial triage. The decision to perform a chest computed tomography scan should be based on the nature of the trauma, the child\\'s clinical condition, and the initial radiographic findings, taking the age-related pretest probabilities of serious injury into account. The principles of as low as reasonably achievable and Image Gently should be followed. The epidemiology and pathophysiology, imaging techniques, characteristic findings, and evidence-based algorithms for pediatric chest trauma are discussed.

  8. Non-invasive Imaging of Sendai Virus Infection in Pharmacologically Immunocompromised Mice: NK and T Cells, but not Neutrophils, Promote Viral Clearance after Therapy with Cyclophosphamide and Dexamethasone.

    Science.gov (United States)

    Mostafa, Heba H; Vogel, Peter; Srinivasan, Ashok; Russell, Charles J

    2016-09-01

    In immunocompromised patients, parainfluenza virus (PIV) infections have an increased potential to spread to the lower respiratory tract (LRT), resulting in increased morbidity and mortality. Understanding the immunologic defects that facilitate viral spread to the LRT will help in developing better management protocols. In this study, we immunosuppressed mice with dexamethasone and/or cyclophosphamide then monitored the spread of viral infection into the LRT by using a noninvasive bioluminescence imaging system and a reporter Sendai virus (murine PIV type 1). Our results show that immunosuppression led to delayed viral clearance and increased viral loads in the lungs. After cessation of cyclophosphamide treatment, viral clearance occurred before the generation of Sendai-specific antibody responses and coincided with rebounds in neutrophils, T lymphocytes, and natural killer (NK) cells. Neutrophil suppression using anti-Ly6G antibody had no effect on infection clearance, NK-cell suppression using anti-NK antibody delayed clearance, and T-cell suppression using anti-CD3 antibody resulted in no clearance (chronic infection). Therapeutic use of hematopoietic growth factors G-CSF and GM-CSF had no effect on clearance of infection. In contrast, treatment with Sendai virus-specific polysera or a monoclonal antibody limited viral spread into the lungs and accelerated clearance. Overall, noninvasive bioluminescence was shown to be a useful tool to study respiratory viral progression, revealing roles for NK and T cells, but not neutrophils, in Sendai virus clearance after treatment with dexamethasone and cyclophosphamide. Virus-specific antibodies appear to have therapeutic potential.

  9. Non-invasive Imaging of Sendai Virus Infection in Pharmacologically Immunocompromised Mice: NK and T Cells, but not Neutrophils, Promote Viral Clearance after Therapy with Cyclophosphamide and Dexamethasone

    Science.gov (United States)

    Mostafa, Heba H.; Vogel, Peter; Srinivasan, Ashok; Russell, Charles J.

    2016-01-01

    In immunocompromised patients, parainfluenza virus (PIV) infections have an increased potential to spread to the lower respiratory tract (LRT), resulting in increased morbidity and mortality. Understanding the immunologic defects that facilitate viral spread to the LRT will help in developing better management protocols. In this study, we immunosuppressed mice with dexamethasone and/or cyclophosphamide then monitored the spread of viral infection into the LRT by using a noninvasive bioluminescence imaging system and a reporter Sendai virus (murine PIV type 1). Our results show that immunosuppression led to delayed viral clearance and increased viral loads in the lungs. After cessation of cyclophosphamide treatment, viral clearance occurred before the generation of Sendai-specific antibody responses and coincided with rebounds in neutrophils, T lymphocytes, and natural killer (NK) cells. Neutrophil suppression using anti-Ly6G antibody had no effect on infection clearance, NK-cell suppression using anti-NK antibody delayed clearance, and T-cell suppression using anti-CD3 antibody resulted in no clearance (chronic infection). Therapeutic use of hematopoietic growth factors G-CSF and GM-CSF had no effect on clearance of infection. In contrast, treatment with Sendai virus—specific polysera or a monoclonal antibody limited viral spread into the lungs and accelerated clearance. Overall, noninvasive bioluminescence was shown to be a useful tool to study respiratory viral progression, revealing roles for NK and T cells, but not neutrophils, in Sendai virus clearance after treatment with dexamethasone and cyclophosphamide. Virus-specific antibodies appear to have therapeutic potential. PMID:27589232

  10. Noninvasive two-photon microscopy imaging of mouse retina and retinal pigment epithelium through the pupil of the eye.

    Science.gov (United States)

    Palczewska, Grazyna; Dong, Zhiqian; Golczak, Marcin; Hunter, Jennifer J; Williams, David R; Alexander, Nathan S; Palczewski, Krzysztof

    2014-07-01

    Two-photon excitation microscopy can image retinal molecular processes in vivo. Intrinsically fluorescent retinyl esters in subcellular structures called retinosomes are an integral part of the visual chromophore regeneration pathway. Fluorescent condensation products of all-trans-retinal accumulate in the eye with age and are also associated with age-related macular degeneration (AMD). Here, we report repetitive, dynamic imaging of these compounds in live mice through the pupil of the eye. By leveraging advanced adaptive optics, we developed a data acquisition algorithm that permitted the identification of retinosomes and condensation products in the retinal pigment epithelium by their characteristic localization, spectral properties and absence in genetically modified or drug-treated mice. This imaging approach has the potential to detect early molecular changes in retinoid metabolism that trigger light- and AMD-induced retinal defects and to assess the effectiveness of treatments for these conditions.

  11. Noninvasive two-photon fluorescence microscopy imaging of mouse retina and RPE through the pupil of the eye

    Science.gov (United States)

    Palczewska, Grazyna; Dong, Zhiqian; Golczak, Marcin; Hunter, Jennifer J.; Williams, David R.; Alexander, Nathan S.; Palczewski, Krzysztof

    2014-01-01

    Two-photon excitation microscopy (TPM) can image retinal molecular processes in vivo. Intrinsically fluorescent retinyl esters in sub-cellular structures called retinosomes are an integral part of the visual chromophore regeneration pathway. Fluorescent condensation products of all–trans–retinal accumulate in the eye with age and are also associated with age-related macular degeneration (AMD). Here we report repetitive, dynamic imaging of these compounds in live mice, through the pupil of the eye. Leveraging advanced adaptive optics we developed a data acquisition algorithm that permitted the identification of retinosomes and condensation products in the retinal pigment epithelium (RPE) by their characteristic localization, spectral properties, and absence in genetically modified or drug-treated mice. This imaging approach has the potential to detect early molecular changes in retinoid metabolism that trigger light and AMD-induced retinal defects and to assess the effectiveness of treatments for these conditions. PMID:24952647

  12. Non-invasive glucagon-like peptide-1 receptor imaging in pancreas with (18)F-Al labeled Cys(39)-exendin-4.

    Science.gov (United States)

    Mi, Baoming; Xu, Yuping; Pan, Donghui; Wang, Lizhen; Yang, Runlin; Yu, Chunjing; Wan, Weixing; Wu, Yiwei; Yang, Min

    2016-02-26

    Glucagon-like peptide-1 receptor (GLP-1R) is abundantly expressed on beta cells and may be an ideal target for the pancreas imaging. Monitoring the GLP-1R of pancreas could be benefit for understanding the pathophysiology of diabetes. In the present study, (18)F-Al labeled exendin-4 analog, (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, was evaluated for PET imaging GLP-1R in the pancreas. The targeting of (18)F-Al labeled exendin-4 analog was examined in healthy and streptozotocin induced diabetic rats. Rats were injected with (18)F-Al-NOTA-MAL-Cys(39)-exendin-4 and microPET imaging was performed at 1 h postinjection, followed by ex vivo biodistribution. GLP-1R expression in pancreas was determined through post mortern examinations. The pancreas of healthy rats was readily visualized after administration of (18)F-Al-NOTA-MAL-Cys(39)-exendin-4, whereas the pancreas of diabetic rats, as well as those from rats co-injected with excess of unlabeled peptides, was barely visible by microPET. At 60 min postinjection, the pancreatic uptakes were 1.02 ± 0.15%ID/g and 0.23 ± 0.05%ID/g in healthy and diabetic rats respectively. Under block, the pancreatic uptakes of non-diabetic rats reduced to 0.21 ± 0.07%ID/g at the same time point. Biodistribution data and IHC staining confirmed the findings of the microPET imaging. The favorable preclinical data indicated that (18)F-Al-NOTA-MAL-Cys(39)-exendin-4may be suitable for non-invasive monitoring functional pancreatic beta cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Non-invasive glucagon-like peptide-1 receptor imaging in pancreas with {sup 18}F-Al labeled Cys{sup 39}-exendin-4

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Baoming [Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006 (China); Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University (Wuxi 4th People' s Hospital), Wuxi, Jiangsu, 214062 (China); Xu, Yuping [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Nanjing Medical University, Nanjing, Jiangsu, 210029 (China); Pan, Donghui; Wang, Lizhen; Yang, Runlin [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Yu, Chunjing; Wan, Weixing [Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University (Wuxi 4th People' s Hospital), Wuxi, Jiangsu, 214062 (China); Wu, Yiwei, E-mail: wuyiwei3988@gmail.com [Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006 (China); Yang, Min, E-mail: ymzfk@yahoo.com.hk [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu, 214063 (China); Nanjing Medical University, Nanjing, Jiangsu, 210029 (China)

    2016-02-26

    Purpose: Glucagon-like peptide-1 receptor (GLP-1R) is abundantly expressed on beta cells and may be an ideal target for the pancreas imaging. Monitoring the GLP-1R of pancreas could be benefit for understanding the pathophysiology of diabetes. In the present study, {sup 18}F-Al labeled exendin-4 analog, {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4, was evaluated for PET imaging GLP-1R in the pancreas. Methods: The targeting of {sup 18}F-Al labeled exendin-4 analog was examined in healthy and streptozotocin induced diabetic rats. Rats were injected with {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4 and microPET imaging was performed at 1 h postinjection, followed by ex vivo biodistribution. GLP-1R expression in pancreas was determined through post mortern examinations. Results: The pancreas of healthy rats was readily visualized after administration of {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4, whereas the pancreas of diabetic rats, as well as those from rats co-injected with excess of unlabeled peptides, was barely visible by microPET. At 60 min postinjection, the pancreatic uptakes were 1.02 ± 0.15%ID/g and 0.23 ± 0.05%ID/g in healthy and diabetic rats respectively. Under block, the pancreatic uptakes of non-diabetic rats reduced to 0.21 ± 0.07%ID/g at the same time point. Biodistribution data and IHC staining confirmed the findings of the microPET imaging. Conclusion: The favorable preclinical data indicated that {sup 18}F-Al-NOTA-MAL-Cys{sup 39}-exendin-4may be suitable for non-invasive monitoring functional pancreatic beta cells.

  14. Multiplanar spiral CT enterography in patients with Crohn's disease using a negative oral contrast material: initial results of a noninvasive imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Reittner, Pia; Goritschnig, Toria; Doerfler, Otto [Department of Radiology, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Petritsch, Wolfgang; Hinterleitner, Thomas [Department of Internal Medicine, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Preidler, Klaus W.; Szolar, Dieter H. [Diagnostikum Graz Sued West, Weblinger Guertel 25, 8054 Graz (Austria)

    2002-09-01

    The aim of this study was to prospectively define the role of multiplanar spiral CT enterography with a new negative oral contrast material for noninvasive assessment of the small bowel in patients with Crohn's disease. Thirty patients with established Crohn's disease prospectively underwent spiral CT enterography at 45-60 min after distension of the small bowel with 1400 ml of a negative oral contrast material (Mucofalk water enema). Spiral CT scans were obtained 50 s after administration of intravenous contrast material with the following parameters: 5-mm collimation; 7.5-mm/s table feed; and 3-mm reconstruction interval. The adequacy of bowel opacification, luminal distension, and the contribution of two-dimensional multiplanar reformatted imaging were assessed by two observers. Spiral CT imaging findings were compared with results of enteroclysis as well as endoscopic and histological findings in all patients. Spiral CT enterography with Mucofalk water enema was well tolerated in 29 of 30 patients. Findings on spiral CT enterography were comparable with those of barium studies in 25 of 30 patients, superior to those on barium studies in 4 patients, and inferior in 1 patient (p<0.05). The addition of multiplanar reformatted images to axial spiral CT scans significantly improved observers' confidence in image interpretation (p<0.05) but did not reveal additional abnormalities. Multiplanar spiral CT enterography with Mucofalk excellently provides information in patients with Crohn's disease. This technique accurately depicts the level of small bowel obstruction and the extent of inflammatory small bowel disease and its extraluminal complications. (orig.)

  15. Non-invasive imaging of ferucarbotran labeled INS-1E cells and rodent islets in vitro and in transplanted diabetic rats.

    Science.gov (United States)

    Auer, Veronika J; Bucher, Julian; Schremmer-Danninger, Elisabeth; Paulmurugan, Ramasamy; Maechler, Pierre; Reiser, Maximilian F; Stangl, Manfred J; Berger, Frank

    2011-04-01

    Transplantation of pancreatic islets is a promising strategy for restoring insulin secretion in diabetes mellitus. To monitor transplanted islets, a method to evaluate the distribution in a non-invasive manner in vivo is needed. INS-1E, a stable differentiated insulin secreting cell line, and rodent islets were used to monitor cell transplantation by MRI. For labeling INS-1E cells in vitro, increasing concentrations of Resovist in culture medium were tested. For MR imaging in a clinical 3T scanner, we placed a layer of labeled INS-1E cells between two layers of 4% gelatin. Viability assay was performed. Cell function was evaluated by static incubation assay to assess insulin secretion. For in vivo imaging, iron labeled rodent islets were transplanted into the liver of streptozotocin induced diabetic rats and visualized by MRI. Blood sugar values were controlled and liver tissue was removed for histological analysis. SPIO labeled INS-1E cells did not show altered viability or reduced glucose stimulated insulin secretion in vitro. Double staining of labeled and unlabeled INS-1E cells showed no difference in the staining pattern. Labeling of rodent islets with SPIOs does not reduce their secretory activity or alter their viability. We visualized SPIO-labeled INS-1E cells and rat islets in vitro using a clinical 3T scanner. Diabetic rats transplanted with SPIO-labeled islets became normoglycemic. MR imaging successfully verified the distribution of labeled transplanted cells in vivo. Labeling INS-1E cells and rat islets with SPIOs does not alter their viability, while enabling MR imaging of labeled cells in vitro and within the living organism.

  16. Non-invasive, whole-plant imaging of chloroplast movement and chlorophyll fluorescence reveals photosynthetic phenotypes independent of chloroplast photorelocation defects in chloroplast division mutants.

    Science.gov (United States)

    Dutta, Siddhartha; Cruz, Jeffrey A; Jiao, Yuhua; Chen, Jin; Kramer, David M; Osteryoung, Katherine W

    2015-10-01

    Leaf chloroplast movement is thought to optimize light capture and to minimize photodamage. To better understand the impact of chloroplast movement on photosynthesis, we developed a technique based on the imaging of reflectance from leaf surfaces that enables continuous, high-sensitivity, non-invasive measurements of chloroplast movement in multiple intact plants under white actinic light. We validated the method by measuring photorelocation responses in Arabidopsis chloroplast division mutants with drastically enlarged chloroplasts, and in phototropin mutants with impaired photorelocation but normal chloroplast morphology, under different light regimes. Additionally, we expanded our platform to permit simultaneous image-based measurements of chlorophyll fluorescence and chloroplast movement. We show that chloroplast division mutants with enlarged, less-mobile chloroplasts exhibit greater photosystem II photodamage than is observed in the wild type, particularly under fluctuating high levels of light. Comparison between division mutants and the severe photorelocation mutant phot1-5 phot2-1 showed that these effects are not entirely attributable to diminished photorelocation responses, as previously hypothesized, implying that altered chloroplast morphology affects other photosynthetic processes. Our dual-imaging platform also allowed us to develop a straightforward approach to correct non-photochemical quenching (NPQ) calculations for interference from chloroplast movement. This correction method should be generally useful when fluorescence and reflectance are measured in the same experiments. The corrected data indicate that the energy-dependent (qE) and photoinhibitory (qI) components of NPQ contribute differentially to the NPQ phenotypes of the chloroplast division and photorelocation mutants. This imaging technology thus provides a platform for analyzing the contributions of chloroplast movement, chloroplast morphology and other phenotypic attributes to the

  17. Noninvasive, label-free, three-dimensional imaging of melanoma with confocal photothermal microscopy: Differentiate malignant melanoma from benign tumor tissue

    Science.gov (United States)

    He, Jinping; Wang, Nan; Tsurui, Hiromichi; Kato, Masashi; Iida, Machiko; Kobayashi, Takayoshi

    2016-07-01

    Skin cancer is one of the most common cancers. Melanoma accounts for less than 2% of skin cancer cases but causes a large majority of skin cancer deaths. Early detection of malignant melanoma remains the key factor in saving lives. However, the melanoma diagnosis is still clinically challenging. Here, we developed a confocal photothermal microscope for noninvasive, label-free, three-dimensional imaging of melanoma. The axial resolution of confocal photothermal microscope is ~3 times higher than that of commonly used photothermal microscope. Three-dimensional microscopic distribution of melanin in pigmented lesions of mouse skin is obtained directly with this setup. Classic morphometric and fractal analysis of sixteen 3D images (eight for benign melanoma and eight for malignant) showed a capability of pathology of melanoma: melanin density and size become larger during the melanoma growth, and the melanin distribution also becomes more chaotic and unregulated. The results suggested new options for monitoring the melanoma growth and also for the melanoma diagnosis.

  18. EPR oxygen imaging and hyperpolarized 13C MRI of pyruvate metabolism as noninvasive biomarkers of tumor treatment response to a glycolysis inhibitor 3-bromopyruvate.

    Science.gov (United States)

    Matsumoto, Shingo; Saito, Keita; Yasui, Hironobu; Morris, H Douglas; Munasinghe, Jeeva P; Lizak, Martin; Merkle, Hellmut; Ardenkjaer-Larsen, Jan Henrik; Choudhuri, Rajani; Devasahayam, Nallathamby; Subramanian, Sankaran; Koretsky, Alan P; Mitchell, James B; Krishna, Murali C

    2013-05-01

    The hypoxic nature of tumors results in treatment resistance and poor prognosis. To spare limited oxygen for more crucial pathways, hypoxic cancerous cells suppress mitochondrial oxidative phosphorylation and promote glycolysis for energy production. Thereby, inhibition of glycolysis has the potential to overcome treatment resistance of hypoxic tumors. Here, EPR imaging was used to evaluate oxygen dependent efficacy on hypoxia-sensitive drug. The small molecule 3-bromopyruvate blocks glycolysis pathway by inhibiting hypoxia inducible enzymes and enhanced cytotoxicity of 3-bromopyruvate under hypoxic conditions has been reported in vitro. However, the efficacy of 3-bromopyruvate was substantially attenuated in hypoxic tumor regions (pO23-bromopyruvate in SCCVII tumor. The discrepant results between in vitro and in vivo data were attributed to biphasic oxygen dependent expression of monocarboxylate transporter-1 in vivo. Expression of monocarboxylate transporter-1 was enhanced in moderately hypoxic (8-15 mmHg) tumor regions but down regulated in severely hypoxic (<5 mmHg) tumor regions. These results emphasize the importance of noninvasive imaging biomarkers to confirm the action of hypoxia-activated drugs.

  19. APEX; current status of the airborne dispersive pushbroom imaging spectrometer

    NARCIS (Netherlands)

    Nieke, J.; Itten, K.I.; Kaiser, J.W.; Schlapfer, D.; Brazile, J.; Debruyn, W.; Meuleman, K.; Kempeneers, P.; Neukom, A.; Feusi, H.; Adolph, P.; Moser, R.; Schilliger, T.; Kohler, P.; Meng, M.; Piesbergen, J.; Strobl, P.; Schaepman, M.E.; Gavira, J.; Ulbrich, G.J.; Meynart, R.

    2004-01-01

    Recently, a joint Swiss/Belgian initiative started a project to build a new generation airborne imaging spectrometer, namely APEX (Airborne Prism Experiment) under the ESA funding scheme named PRODEX. APEX is a dispersive pushbroom imaging spectrometer operating in the spectral range between 380 - 2

  20. Imaging the male reproductive tract: current trends and future directions.

    NARCIS (Netherlands)

    Futterer, J.J.; Heijmink, S.W.T.P.J.; Spermon, J.R.

    2008-01-01

    The male reproductive system encompasses several organs: the testes, ejaculatory ducts, seminal vesicles, prostate, and penis. The function of this system is to accomplish reproduction. Diagnostic imaging modalities, such as ultrasound, CT, MR imaging, and positron emission tomography (PET), are inc

  1. Non-invasive magnetic resonance imaging diagnosis of presumed intermedioradial carpal bone avascular necrosis in the dog.

    Science.gov (United States)

    Pownder, Sarah L; Cooley, Stacy; Hayashi, Kei; Bezuidenhout, Abraham; Koff, Matthew F; Potter, Hollis G

    2016-08-01

    A 5-year-old, spayed female Weimaraner dog was evaluated for progressive left forelimb lameness localized to the carpus. Magnetic resonance imaging (MRI) was used to arrive at a presumptive diagnosis of intermedioradial carpal (IRC) bone fracture with avascular necrosis (AVN). To the authors' knowledge, this is the first report of naturally occurring AVN of the canine IRC diagnosed using MRI.

  2. Bioluminescence : the potential of a non-invasive bio-optical imaging technique and improvement of animal research

    NARCIS (Netherlands)

    Hesselink, J. W.; van Dam, G. M.

    2007-01-01

    Bioluminescence is an optical imaging technique that exploits the emission of photons at specific wavelengths based on energy-dependent reactions catalysed by luciferases. The technique makes it possible to monitor measure, and track biological processes in living animals. A short review is

  3. Bioluminescence : the potential of a non-invasive bio-optical imaging technique and improvement of animal research

    NARCIS (Netherlands)

    Hesselink, J. W.; van Dam, G. M.

    2007-01-01

    Bioluminescence is an optical imaging technique that exploits the emission of photons at specific wavelengths based on energy-dependent reactions catalysed by luciferases. The technique makes it possible to monitor measure, and track biological processes in living animals. A short review is presente

  4. Noninvasive Imaging of Acute Renal Allograft Rejection by Ultrasound Detection of Microbubbles Targeted to T-lymphocytes in Rats.

    NARCIS (Netherlands)

    Grabner, A.; Kentrup, D.; Mühlmeister, M.; Pawelski, H.; Biermann, C.; Bettinger, T.; Pavenstadt, H.; Schlatter, E.; Tiemann, K.; Reuter, S.

    2016-01-01

    PURPOSE: We propose CD3-antibody-mediated contrast-enhanced ultrasonography using human T-lymphocytes for image-based diagnosis of acute allograft rejection (AR) established in a rat renal transplantation model. MATERIALS AND METHODS: 15 minutes after tail vein injection of 30 x 10(6) human T-lympho

  5. Weight status and body image perceptions in adolescents: current perspectives.

    Science.gov (United States)

    Voelker, Dana K; Reel, Justine J; Greenleaf, Christy

    2015-01-01

    Adolescence represents a pivotal stage in the development of positive or negative body image. Many influences exist during the teen years including transitions (eg, puberty) that affect one's body shape, weight status, and appearance. Weight status exists along a spectrum between being obese (ie, where one's body weight is in the 95th percentile for age and gender) to being underweight. Salient influences on body image include the media, which can target adolescents, and peers who help shape beliefs about the perceived body ideal. Internalization of and pressures to conform to these socially prescribed body ideals help to explain associations between weight status and body image. The concepts of fat talk and weight-related bullying during adolescence greatly contribute to an overemphasis on body weight and appearance as well as the development of negative body perceptions and dissatisfaction surrounding specific body parts. This article provides an overview of the significance of adolescent development in shaping body image, the relationship between body image and adolescent weight status, and the consequences of having a negative body image during adolescence (ie, disordered eating, eating disorders, and dysfunctional exercise). Practical implications for promoting a healthy weight status and positive body image among adolescents will be discussed.

  6. Direct imaging of neural currents using ultra-low field magnetic resonance techniques

    Science.gov (United States)

    Volegov, Petr L.; Matlashov, Andrei N.; Mosher, John C.; Espy, Michelle A.; Kraus, Jr., Robert H.

    2009-08-11

    Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

  7. Reconstruction of conductivity and current density images using only one component of magnetic field measurements.

    Science.gov (United States)

    Seo, Jin Keun; Yoon, Jeong-Rock; Woo, Eung Je; Kwon, Ohin

    2003-09-01

    Magnetic resonance current density imaging (MRCDI) is to provide current density images of a subject using a magnetic resonance imaging (MRI) scanner with a current injection apparatus. The injection current generates a magnetic field that we can measure from MR phase images. We obtain internal current density images from the measured magnetic flux densities via Ampere's law. However, we must rotate the subject to acquire all of the three components of the induced magnetic flux density. This subject rotation is impractical in clinical MRI scanners when the subject is a human body. In this paper, we propose a way to eliminate the requirement of subject rotation by careful mathematical analysis of the MRCDI problem. In our new MRCDI technique, we need to measure only one component of the induced magnetic flux density and reconstruct both cross-sectional conductivity and current density images without any subject rotation.

  8. Modern dental imaging: a review of the current technology and clinical applications in dental practice

    Energy Technology Data Exchange (ETDEWEB)

    Vandenberghe, Bart; Jacobs, Reinhilde [Katholieke Universiteit Leuven, Oral Imaging Centre, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Leuven (Belgium); Bosmans, Hilde [Katholieke Universiteit Leuven, Radiology Section, Department of Medical Diagnostic Sciences, Leuven (Belgium)

    2010-11-15

    A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental ''in-office'' radiographic techniques are discussed. (orig.)

  9. A Novel Multivoxel-Based Quantitation of Metabolites and Lipids Noninvasively Combined with Diffusion-Weighted Imaging in Breast Cancer

    Science.gov (United States)

    2013-10-01

    short measurement times for the diagnosis of breast cancer and improve the specificity of MR imaging (19-21). However, new technological developments...132: 2145–2147. 29. Maciejewski MW, Mobli M, Schuyler A, Stern A, Hoch J. Data sampling in multidimensional NMR: fundamentals and strategies. Top...wileyonlinelibrary.com/journal/nbm Copyright © 2013 John Wiley & Sons, Ltd. NMR Biomed. 2014; 27: 191–201 200 31. Mobli M, Hoch JC. Maximum entropy spectral

  10. Non-invasive Bioluminescence Imaging of Myoblast-Mediated Hypoxia-Inducible Factor-1 Alpha Gene Transfer

    Science.gov (United States)

    Gheysens, Olivier; Chen, Ian Y.; Rodriguez-Porcel, Martin; Chan, Carmel; Rasooly, Julia; Vaerenberg, Caroline; Paulmurugan, Ramasamy; Willmann, Juergen K.; Deroose, Christophe; Wu, Joseph; Gambhir, Sanjiv S.

    2011-01-01

    Purpose We tested a novel imaging strategy, in which both the survival of transplanted myoblasts and their therapeutic transgene expression, a recombinant hypoxia-inducible factor-1α (HIF-1α-VP2), can be monitored using firefly luciferase (fluc) and Renilla luciferase (hrl) bioluminescence reporter genes, respectively. Procedures The plasmid pUbi-hrl-pUbi-HIF-1α-VP2, which expresses both hrl and HIF-1α-VP2 using two ubiquitin promoters, was characterized in vitro. C2c12 myoblasts stably expressing fluc and transiently transfected with pUbi-hrl-pUbi-HIF-1α-VP2 were injected into the mouse hindlimb. Both hrl and fluc expression were monitored using bioluminescence imaging (BLI). Results Strong correlations existed between the expression of hRL and each of HIF-1α-VP2, VEGF, and PlGF (r2>0.83, r2>0.82, and r2>0.97, respectively). In vivo, both transplanted cells and HIF-1α-VP2 transgene expression were successfully imaged using BLI. Conclusions An objective evaluation of myoblast-mediated gene transfer in living mice can be performed by monitoring both the survival and the transgene expression of transplanted myoblasts using the techniques developed herein. PMID:21267661

  11. Thermal imaging for current D&S priorities

    Science.gov (United States)

    Craig, Robert; Parsons, John F.

    2012-11-01

    Supplying thermal imagers for today's operational needs requires flexibility, responsiveness and ever reducing costs. This paper will use the latest thermal imager development in the Catherine range from Thales UK to address the technical interactions with such issues as modularity, re-use, regions of deployment and supply chain management. All this is in the context of the increasingly public operations and the pressures on validating performance especially when weapon aiming is involved.

  12. Feasibility of non-invasive temperature estimation by the assessment of the average gray-level content of B-mode images.

    Science.gov (United States)

    Teixeira, C A; Alvarenga, A V; Cortela, G; von Krüger, M A; Pereira, W C A

    2014-08-01

    This paper assesses the potential of the average gray-level (AVGL) from ultrasonographic (B-mode) images to estimate temperature changes in time and space in a non-invasive way. Experiments were conducted involving a homogeneous bovine muscle sample, and temperature variations were induced by an automatic temperature regulated water bath, and by therapeutic ultrasound. B-mode images and temperatures were recorded simultaneously. After data collection, regions of interest (ROIs) were defined, and the average gray-level variation computed. For the selected ROIs, the AVGL-Temperature relation were determined and studied. Based on uniformly distributed image partitions, two-dimensional temperature maps were developed for homogeneous regions. The color-coded temperature estimates were first obtained from an AVGL-Temperature relation extracted from a specific partition (where temperature was independently measured by a thermocouple), and then extended to the other partitions. This procedure aimed to analyze the AVGL sensitivity to changes not only in time but also in space. Linear and quadratic relations were obtained depending on the heating modality. We found that the AVGL-Temperature relation is reproducible over successive heating and cooling cycles. One important result was that the AVGL-Temperature relations extracted from one region might be used to estimate temperature in other regions (errors inferior to 0.5 °C) when therapeutic ultrasound was applied as a heating source. Based on this result, two-dimensional temperature maps were developed when the samples were heated in the water bath and also by therapeutic ultrasound. The maps were obtained based on a linear relation for the water bath heating, and based on a quadratic model for the therapeutic ultrasound heating. The maps for the water bath experiment reproduce an acceptable heating/cooling pattern, and for the therapeutic ultrasound heating experiment, the maps seem to reproduce temperature profiles

  13. A semi-automated method for non-invasive internal organ weight estimation by post-mortem magnetic resonance imaging in fetuses, newborns and children

    Energy Technology Data Exchange (ETDEWEB)

    Thayyil, Sudhin [Centre for Cardiovascular MR, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London (United Kingdom)], E-mail: s.thayyil@ich.ucl.ac.uk; Schievano, Silvia [Centre for Cardiovascular MR, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London (United Kingdom); Robertson, Nicola J. [EGA UCL Institute for Women' s Health, University College London (United Kingdom); Jones, Rodney [Centre for Cardiovascular MR, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London (United Kingdom); Chitty, Lyn S. [EGA UCL Institute for Women' s Health, University College London (United Kingdom); Clinical Molecular Genetics Unit, Institute of Child Health, London (United Kingdom); Sebire, Neil J. [Histopathology, Great Ormond Street Hospital NHS Trust, London (United Kingdom); Taylor, Andrew M. [Centre for Cardiovascular MR, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London (United Kingdom)

    2009-11-15

    Magnetic resonance (MR) imaging allows minimally invasive autopsy, especially when consent is declined for traditional autopsy. Estimation of individual visceral organ weights is an important component of traditional autopsy. Objective: To examine whether a semi-automated can be used for non-invasive internal organ weight measurement using post-mortem MR imaging in fetuses, newborns and children. Methods: Phase 1: In vitro scanning of 36 animal organs (heart, liver, kidneys) was performed to check the accuracy of volume reconstruction methodology. Real volumes were measured by water displacement method. Phase 2: Sixty-five whole body post-mortem MR scans were performed in fetuses (n = 30), newborns (n = 5) and children (n = 30) at 1.5 T using a 3D TSE T2-weighted sequence. These data were analysed offline using the image processing software Mimics 11.0. Results: Phase 1: Mean difference (S.D.) between estimated and actual volumes were -0.3 (1.5) ml for kidney, -0.7 (1.3) ml for heart, -1.7 (3.6) ml for liver in animal experiments. Phase 2: In fetuses, newborns and children mean differences between estimated and actual weights (S.D.) were -0.6 (4.9) g for liver, -5.1 (1.2) g for spleen, -0.3 (0.6) g for adrenals, 0.4 (1.6) g for thymus, 0.9 (2.5) g for heart, -0.7 (2.4) g for kidneys and 2.7 (14) g for lungs. Excellent co-correlation was noted for estimated and actual weights (r{sup 2} = 0.99, p < 0.001). Accuracy was lower when fetuses were less than 20 weeks or less than 300 g. Conclusion: Rapid, accurate and reproducible estimation of solid internal organ weights is feasible using the semi-automated 3D volume reconstruction method.

  14. Non-invasive assessment of intratumoral vascularity using arterial spin labeling: A comparison to susceptibility-weighted imaging for the differentiation of primary cerebral lymphoma and glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Furtner, J., E-mail: julia.furtner@meduniwien.ac.at [Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria); Schöpf, V., E-mail: veronika.schoepf@meduniwien.ac.at [Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna (Austria); Preusser, M., E-mail: matthias.preusser@meduniwien.ac.at [Department of Medicine I, Division of Oncology, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria); Asenbaum, U., E-mail: ulrika.asenbaum@meduniwien.ac.at [Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna (Austria); Woitek, R., E-mail: ramona.woitek@meduniwien.ac.at [Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna (Austria); Wöhrer, A., E-mail: adelheid.woehrer@meduniwien.ac.at [Institute of Neurology, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria); Hainfellner, J.A., E-mail: johannes.hainfellner@meduniwien.ac.at [Institute of Neurology, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria); Wolfsberger, S., E-mail: stefan.wolfsberger@meduniwien.ac.at [Department of Neurosurgery, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria); Prayer, D., E-mail: daniela.prayer@meduniwien.ac.at [Department of Biomedical Imaging und Image-guided Therapy, Medical University of Vienna (Austria); Comprehensive Cancer Center-Central Nervous System Tumors Unit (CCC-CNS), Medical University of Vienna (Austria)

    2014-05-15

    Using conventional MRI methods, the differentiation of primary cerebral lymphomas (PCNSL) and other primary brain tumors, such as glioblastomas, is difficult due to overlapping imaging characteristics. This study was designed to discriminate tumor entities using normalized vascular intratumoral signal intensity values (nVITS) obtained from pulsed arterial spin labeling (PASL), combined with intratumoral susceptibility signals (ITSS) from susceptibility-weighted imaging (SWI). Thirty consecutive patients with glioblastoma (n = 22) and PCNSL (n = 8), histologically classified according to the WHO brain tumor classification, were included. MRIs were acquired on a 3 T scanner, and included PASL and SWI sequences. nVITS was defined by the signal intensity ratio between the tumor and the contralateral normal brain tissue, as obtained by PASL images. ITSS was determined as intratumoral low signal intensity structures detected on SWI sequences and were divided into four different grades. Potential differences in the nVITS and ITSS between glioblastomas and PCNSLs were revealed using statistical testing. To determine sensitivity, specificity, and diagnostic accuracy, as well as an optimum cut-off value for the differentiation of PCNSL and glioblastoma, a receiver operating characteristic analysis was used. We found that nVITS (p = 0.011) and ITSS (p = 0.001) values were significantly higher in glioblastoma than in PCNSL. The optimal cut-off value for nVITS was 1.41 and 1.5 for ITSS, with a sensitivity, specificity, and accuracy of more than 95%. These findings indicate that nVITS values have a comparable diagnostic accuracy to ITSS values in differentiating glioblastoma and PCNSL, offering a completely non-invasive and fast assessment of tumoral vascularity in a clinical setting.

  15. Molecular In Vivo Imaging Using a Noninvasive Cardiac-Specific MLC-2v Promoter Driven Dual-Gene Recombinant Lentivirus Monitoring System.

    Directory of Open Access Journals (Sweden)

    Miao Zhang

    Full Text Available Our study aimed to demonstrate the feasibility of using the sodium/iodide symporter (NIS to monitor vascular endothelial growth factor (VEGF165 expression in vivo.We constructed a recombinant lentivirus plasmid with the MLC-2v promoter driving the sodium/iodide symporter (NIS reporter gene linked to the VEGF165 gene. Expression of NIS and VEGF gene were identified by Western blot. On days 2 and 54, 99mTc-MIBI imaging was used to evaluate changes in myocardial ischemia. Noninvasive 125I micro-SPECT/CT imaging was used to assess the expression of NIS reporter gene dynamically over the next 2 months.Western blot analysis showed that both NIS and VEGF165 were highly expressed in rat cardiomyoblast H9C2 cells transduced with Lenti-MLC-2v-NIS--VEGF165. 125I micro-SPECT/CT reporter imaging showed higher uptake in mouse myocardium transduced with Lenti-MLC-2v-VEGF165-IRES-NIS. NIS expression peaked on day 1 after transduction followed by a progressive decline to negligible levels by day 21. On day 1, mean 125I activity value in group 1 was higher than that in group 2 (P 0.05. In group 1 (test group, 99mTc-MIBI SPECT/CT revealed improvements in perfusion and wall thickening in the apical anterior wall. Mean IOD values of NIS and CD34 were significantly higher in group 1 than group 3 (P<0.05. Our study proved mean I-125 uptake was significantly correlated with mean IOD value of NIS and CD34 (P<0.05.This study demonstrates the feasibility of using the NIS gene to monitor VEGF165 expression in a mouse myocardial ischemia model.

  16. Optical flow and image segmentation analysis for noninvasive precise mapping of microwave thermal ablation in X-ray CT scans - ex vivo study.

    Science.gov (United States)

    Ziv, Omri; Goldberg, S Nahum; Nissenbaum, Yitzhak; Sosna, Jacob; Weiss, Noam; Azhari, Haim

    2017-09-20

    To develop image processing algorithms for noninvasive mapping of microwave thermal ablation using X-ray CT. Ten specimens of bovine liver were subjected to microwave ablation (20-80 W, 8 min) while scanned by X-ray CT at 5 s intervals. Specimens were cut and manually traced by two observers. Two algorithms were developed and implemented to map the ablation zone. The first algorithm utilises images segmentation of Hounsfield units changes (ISHU). The second algorithm utilises radial optical flow (ROF). Algorithm sensitivity to spatiotemporal under-sampling was assessed by decreasing the acquisition rate and reducing the number of acquired projections used for image reconstruction in order to evaluate the feasibility of implementing radiation reduction techniques. The average radial discrepancy between the ISHU and ROF contours and the manual tracing were 1.04±0.74 and 1.16±0.79mm, respectively. When diluting the input data, the ISHU algorithm retained its accuracy, ranging from 1.04 to 1.79mm. By contrast, the ROF algorithm performance became inconsistent at low acquisition rates. Both algorithms were not sensitive to projections reduction, (ISHU: 1.24±0.83mm, ROF: 1.53±1.15mm, for reduction by eight fold). Ablations near large blood vessels affected the ROF algorithm performance (1.83±1.30mm; p mapping algorithms can provide highly accurate contouring of the ablation zone at low scan rates. The ISHU algorithm may be more suitable for clinical practice as it appears more robust when radiation dose reduction strategies are employed and when the ablation zone is near large blood vessels.

  17. Weight status and body image perceptions in adolescents: current perspectives

    Directory of Open Access Journals (Sweden)

    Voelker DK

    2015-08-01

    Full Text Available Dana K Voelker,1 Justine J Reel,2 Christy Greenleaf3 1West Virginia University, College of Physical Activity and Sport Sciences, Morgantown, WV, 2University of North Carolina Wilmington, College of Health and Human Services, Wilmington, NC, 3University of Wisconsin–Milwaukee, College of Health Sciences, Milwaukee, WI, USA Abstract: Adolescence represents a pivotal stage in the development of positive or negative body image. Many influences exist during the teen years including transitions (eg, puberty that affect one’s body shape, weight status, and appearance. Weight status exists along a spectrum between being obese (ie, where one’s body weight is in the 95th percentile for age and gender to being underweight. Salient influences on body image include the media, which can target adolescents, and peers who help shape beliefs about the perceived body ideal. Internalization of and pressures to conform to these socially prescribed body ideals help to explain associations between weight status and body image. The concepts of fat talk and weight-related bullying during adolescence greatly contribute to an overemphasis on body weight and appearance as well as the development of negative body perceptions and dissatisfaction surrounding specific body parts. This article provides an overview of the significance of adolescent development in shaping body image, the relationship between body image and adolescent weight status, and the consequences of having a negative body image during adolescence (ie, disordered eating, eating disorders, and dysfunctional exercise. Practical implications for promoting a healthy weight status and positive body image among adolescents will be discussed. Keywords: adolescence, eating disorders, obesity, bullying, puberty, physical activity

  18. Noninvasive assessment of gene transfer and expression by in vivo functional and morphologic imaging in a rabbit tumor model.

    Directory of Open Access Journals (Sweden)

    Murali K Ravoori

    Full Text Available PURPOSE: To evaluate the importance of morphology in quantifying expression after in vivo gene transfer and to compare gene expression after intra-arterial (IA and intra-tumoral (IT delivery of adenovirus expressing a SSTR2-based reporter gene in a large animal tumor model. MATERIALS AND METHODS: Tumor directed IA or IT delivery of adenovirus containing a human somatostatin receptor type 2A (Ad-CMV-HA-SSTR2A gene chimera or control adenovirus (Ad-CMV-GFP was performed in VX2 tumors growing in both rabbit thighs. Three days later, ¹¹¹In-octreotide was administered intravenously after CT imaging using a clinical scanner. ¹¹¹In-octreotide uptake in tumors was evaluated the following day using a clinical gamma-camera. Gene expression was normalized to tumor weight with and without necrosis. This procedure was repeated on nine additional rabbits to investigate longitudinal gene expression both 5 days and 2 weeks after adenovirus delivery. CT images were used to evaluate tumor morphology and excised tissue samples were analyzed to determine ¹¹¹In-octreotide biodistribution ex vivo. RESULTS: VX2 tumors infected with Ad-CMV-HA-SSTR2 had greater ¹¹¹In-octreotide uptake than with control virus (P<0.05. Intra-arterial and intra-tumoral routes resulted in similar levels of gene expression. Longitudinally, expression appeared to wane at 2 weeks versus 5 days after delivery. Areas of necrosis did not demonstrate significant uptake ex vivo. Morphology identified areas of necrosis on contrast enhanced CT and upon excluding necrosis, in vivo biodistribution analysis resulted in greater percent injected dose per gram (P<0.01 and corresponded better with ex vivo biodistribution(r = 0.72, P<0.01, Coefficient of the x-variable = .72 at 2 weeks than without excluding necrosis (P<0.01. CONCLUSION: Tumor specificity and high transgene expression can be achieved in tumors via both tumor directed intra-arterial and intra-tumoral delivery in a large

  19. Beyond the current noise limit in imaging through turbulent medium

    CERN Document Server

    Popowicz, A; Pollo, A; Smolka, B

    2015-01-01

    Shift-and-add is an approach employed to mitigate the phenomenon of resolution degradation in images acquired through a turbulent medium. Using this technique, a large number of consecutive short exposures is registered below the coherence time of the atmosphere or other blurring medium. The acquired images are shifted to the position of the brightest speckle and stacked together to obtain high-resolution and high signal-to-noise frame. In this paper we present a highly efficient method for determination of frames shifts, even if in a single frame the object cannot be distinguished from the background noise. The technique utilizes our custom genetic algorithm, which iteratively evolves a set of image shifts. We used the maximal energy of stacked images as an objective function for shifts estimation and validate the efficiency of the method on simulated and real images of simple and complex sources. Obtained results confirmed, that our proposed method allows for the recovery of spatial distribution of objects ...

  20. Imaging in primary penile cancer: current status and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Kochhar, Rohit; Taylor, Ben [Christie, NHS Foundation Trust, Department of Radiology, Manchester (United Kingdom); Sangar, Vijay [Christie, NHS Foundation Trust, Department of Urology, Manchester (United Kingdom)

    2010-01-15

    Penile cancer is a rare neoplasm in the developed world. Clinical assessment often results in inaccurate staging and radiological techniques have a key role in staging and postoperative assessment. Magnetic resonance imaging (MRI) depicts penile anatomy in detail and is the most accurate technique for local staging and postoperative follow-up. MRI and ultrasound (US), although helpful for assessment of lymph nodes, are not reliable enough for accurate nodal staging. US-guided fine needle aspiration cytology (FNAC), however, remains a valuable tool to confirm metastases in suspicious inguinal nodes. Lymphoscintigraphy with dynamic sentinel node biopsy (DSNB) is a promising technique used to predict occult lymph node metastases. Novel imaging techniques such as positron emission tomography/computed tomography (PET-CT) and nanoparticle enhanced MRI have high sensitivity and specificity for lymph node metastases but their availability is limited and clinical utility is not fully established. The radiologist needs to be familiar with the normal penile anatomy, imaging appearances of pre- and post-treatment penile cancer, and the advantages and limitations of the available imaging techniques. This review highlights the above points and presents a systematic approach to make the best use of imaging in the management of patients with penile cancer. (orig.)

  1. Non-invasive depth profile imaging of the stratum corneum using confocal Raman microscopy: first insights into the method.

    Science.gov (United States)

    Ashtikar, Mukul; Matthäus, Christian; Schmitt, Michael; Krafft, Christoph; Fahr, Alfred; Popp, Jürgen

    2013-12-18

    The stratum corneum is a strong barrier that must be overcome to achieve successful transdermal delivery of a pharmaceutical agent. Many strategies have been developed to enhance the permeation through this barrier. Traditionally, drug penetration through the stratum corneum is evaluated by employing tape-stripping protocols and measuring the content of the analyte. Although effective, this method cannot provide a detailed information regarding the penetration pathways. To address this issue various microscopic techniques have been employed. Raman microscopy offers the advantage of label free imaging and provides spectral information regarding the chemical integrity of the drug as well as the tissue. In this paper we present a relatively simple method to obtain XZ-Raman profiles of human stratum corneum using confocal Raman microscopy on intact full thickness skin biopsies. The spectral datasets were analysed using a spectral unmixing algorithm. The spectral information obtained, highlights the different components of the tissue and the presence of drug. We present Raman images of untreated skin and diffusion patterns for deuterated water and beta-carotene after Franz-cell diffusion experiment.

  2. New imaging technique using degree of polarization for the study of polarimetric properties for non-invasive biomedical diagnostic

    Science.gov (United States)

    Buscemi, Isabella C.; Guyot, Steve; Lemoine, Jacques

    2012-06-01

    This research proposes a new imaging technique for near real time multispectral acquisition using CCD RGB cameras of the so called "Degree Of Polarization" (DOP) in polarimetry for future clinical investigation. The aim of exploiting the DOP as the contrast element is to demonstrate that the elliptical DOP provides more information characterizing complex medium than the more traditional linear and circular ones. The system considers an incoherent input white light beam and opportunely calibrated nematic crystals (LCVR), so no mechanical tools are necessary. The particular features of the system indicate it to be the perfect candidate for a new imaging system considering in-vivo (as well as ex-vivo) non invasive superficial diagnostic for medical application as dermatologic diagnostics, since no type of sample preparation is necessary, i.e. tissue biopsy, radiation or contrast agent injection. Thus the biomedical application of this method suggests a simple, direct, fast and also easily exploitable future employment, as a desirable mean for clinical investigation but also for digital recognition in biometrics. Further new elements to improve the model of light scattering and matter-light interaction will be acquired, in particular considering a very complete characterization of the system response using latex microspheres suspension to simulate turbid media with different concentration.

  3. Non-invasive volumetric optoacoustic imaging of cardiac cycles in acute myocardial infarction model in real-time

    Science.gov (United States)

    Lin, Hasiao-Chun Amy; Déan-Ben, Xosé Luís.; Kimm, Melanie; Kosanke, Katja; Haas, Helena; Meier, Reinhard; Lohöfer, Fabian; Wildgruber, Moritz; Razansky, Daniel

    2017-03-01

    Extraction of murine cardiac functional parameters on a beat-by-beat basis remains challenging with the existing imaging modalities. Novel methods enabling in vivo characterization of functional parameters at a high temporal resolution are poised to advance cardiovascular research and provide a better understanding of the mechanisms underlying cardiac diseases. We present a new approach based on analyzing contrast-enhanced optoacoustic (OA) images acquired at high volumetric frame rate without using cardiac gating or other approaches for motion correction. Acute myocardial infarction was surgically induced in murine models, and the method was modified to optimize for acquisition of artifact-free optoacoustic data. Infarcted hearts could be differentiated from healthy controls based on a significantly higher pulmonary transit time (PTT: infarct 2.07 s vs. healthy 1.34 s), while no statistically significant difference was observed in the heart rate (318 bpm vs. 309 bpm). In combination with the proven ability of optoacoustics to track targeted probes within the injured myocardium, our method is capable of depicting cardiac anatomy, function, and molecular signatures on a beat-by-beat basis, both with high spatial and temporal resolution, thus providing new insights into the study of myocardial ischemia.

  4. Particle Image Velocimetry Study of Density Current Fronts

    Science.gov (United States)

    Martin, Juan Ezequiel

    2009-01-01

    Gravity currents are flows that occur when a horizontal density difference causes fluid to move under the action of gravity; density currents are a particular case, for which the scalar causing the density difference is conserved. Flows with a strong effect of the horizontal density difference, even if only partially driven by it--such as the…

  5. Role of diffusion weighted imaging in musculoskeletal infections: Current perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Yogesh [Yale New Haven Health System at Bridgeport Hospital, Department of Radiology, Bridgeport, CT (United States); Khaleel, Mohammad [UT Southwestern Medical Center, Department of Orthopaedic Surgery, Dallas, TX (United States); Boothe, Ethan; Awdeh, Haitham [UT Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Wadhwa, Vibhor [University of Arkansas for Medical Sciences, Department of Radiology, Little Rock, AR (United States); Chhabra, Avneesh [UT Southwestern Medical Center, Department of Orthopaedic Surgery, Dallas, TX (United States); UT Southwestern Medical Center, Department of Radiology, Dallas, TX (United States)

    2017-01-15

    Accurate diagnosis and prompt therapy of musculoskeletal infections are important prognostic factors. In most cases, clinical history, examination and laboratory findings help one make the diagnosis, and routine magnetic resonance imaging (MRI) is useful to identify the extent of the disease process. However, in many situations, a routine MRI may not be specific enough especially if the patient cannot receive contrast intravenously, thereby delaying the appropriate treatment. Diffusion-weighted imaging (DWI) can help in many such situations by providing additional information, accurate characterization and defining the extent of the disease, so that prompt treatment can be initiated. In this article, we illustrate the imaging findings of the spectrum of musculoskeletal infections, emphasizing the role of DWI in this domain. (orig.)

  6. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S. [GE Healthcare Medical Diagnostics, John F. Welch Technology Center, Bangalore (India).; Bhalla, R.; Pickett, R.; Luthra, S.K. [GE Healthcare Medical Diagnostics, The Grove Centre, Amersham (United Kingdom)

    2012-07-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [{sup 123}I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [{sup 123}I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also

  7. Doppler Tissue Imaging: A Non-Invasive Technique for Estimation of Left Ventricular End Diastolic Pressure in Severe Mitral Regurgitation

    Directory of Open Access Journals (Sweden)

    Mojtaba Salarifar

    2010-08-01

    Full Text Available Background: Conventional Doppler measurements, including mitral inflow and pulmonary venous flow, are used to estimate left ventricular end diastolic pressure (LVEDP. However, these parameters have limitations in predicting LVEDP among patients with mitral regurgitation. This study sought to establish whether the correlation between measurements derived from tissue Doppler echocardiography and LVEDP remains valid in the setting of severe mitral regurgitation.Methods: Thirty patients (mean age: 57.37 ± 13.29 years with severe mitral regurgitation and a mean left ventricular ejection fraction (EF of 46.0 ± 14.95 were enrolled; 16 (53.4% patients were defined to have EF < 50% and 14 (46.6% patients had EF ≥ 50%. Doppler signals from the mitral inflow, pulmonary venous flow, and Doppler tissue imaging indices were obtained, and LVEDP was measured invasively through cardiac catheterization.Results: The majority of the standard Doppler and Doppler tissue imaging indices were not significantly correlated with LVEDP in the univariate analysis. In the multiple linear regression, however, early (E transmitral velocity to annular E' (E/E' ratio (ß = 1.09, p value < 0.01, E wave velocity to propagation velocity (E/Vp ratio (ß = 7.87, p value < 0.01, and isovolumic relaxation time (ß = 0.21, p value = 0.01 were shown as independent predictors of LVEDP (R2 = 91.7%.Conclusion: The ratio of E/Vp and E/E' ratio and also the isovolumic relaxation time could be applied properly to estimate LVEDP in mitral regurgitation patients even in the setting of severe mitral regurgitation.

  8. Acoustic radiation force impulse imaging for non-invasive assessment of renal histopathology in chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Qiao Hu

    Full Text Available OBJECTIVE: To investigate the stiffness values obtained by acoustic radiation force impulse (ARFI quantification in assessing renal histological fibrosis of chronic kidney disease (CKD. METHODS: 163 patients with CKD and 32 healthy volunteers were enrolled between June 2013 and April 2014. ARFI quantification, given as shear wave velocity (SWV, was performed to measure renal parenchyma stiffness. Diagnostic performance of ARFI imaging and conventional ultrasound (US were compared with histologic scores at renal biopsy. Intra- and inter-observer reliability of SWV measurement was analyzed. RESULTS: In CKD patients, SWV measurements correlated significantly with pathological parameters (r = -0.422--0.511, P<0.001, serum creatinine (r = -0.503, P<0.001, and glomerular filtration rate (r = 0.587, P<0.001. The mean SWV in kidneys with severely impaired (histologic score: ≥19 points was significant lower than that mildly impaired (histologic score: ≤9 points, moderately impaired (histologic score: 10-18 points, and control groups (all P<0.001. Receiver operating characteristic (ROC curves analyses indicated that the area under the ROC curve for the diagnosis of renal histological fibrosis using ARFI imaging was superior to these conventional US parameters. Using the optimal cut-off value of 2.65 m/s for the diagnosis of mildly impaired kidneys, 2.50 m/s for moderately impaired kidneys, and 2.33 m/s for severely impaired kidneys, the corresponding area under the ROC curves were 0.735, 0.744, and 0.895, respectively. Intra- and intre-observer agreement of SWV measurements were 0.709 (95% CI: 0.390-0.859, P<0.001 and 0.627 (95% CI: 0.233-0.818, P = 0.004, respectively. CONCLUSIONS: ARFI may be an effective tool for evaluating renal histological fibrosis in CKD patients.

  9. Noninvasive Imaging of Myocardial Inflammation in Myocarditis using 68Ga-tagged Mannosylated Human Serum Albumin Positron Emission Tomography

    Science.gov (United States)

    Lee, Seung-Pyo; Im, Hyung-Jun; Kang, Shinae; Chung, Seock-Jin; Cho, Ye Seul; Kang, Hyejeong; Park, Ho Seon; Hwang, Do-Won; Park, Jun-Bean; Paeng, Jin-Chul; Cheon, Gi-Jeong; Lee, Yun-Sang; Jeong, Jae Min; Kim, Yong-Jin

    2017-01-01

    The diagnosis of myocarditis traditionally relies on invasive endomyocardial biopsy but none of the imaging studies so far are specific for infiltration of the inflammatory cells itself. We synthesized 68Ga-2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) mannosylated human serum albumin (MSA) by conjugating human serum albumin with mannose, followed by conjugation with NOTA and labeling it with 68Ga. The efficacy of 68Ga-NOTA-MSA positron emission tomography (PET) for imaging myocardial inflammation was tested in a rat myocarditis model. A significant number of mannose receptor-positive inflammatory cells infiltrated the myocardium in both human and rat myocarditis tissue. 68Ga-NOTA-MSA uptake was upregulated in organs of macrophage accumulation, such as liver, spleen, bone marrow and myocardium (0.32 (0.31~0.33) for normal versus 1.02 (0.86~1.06) for myocarditis (median (range), SUV); n=4~6 per group, p-value=0.01). 68Ga-NOTA-MSA uptake in the left ventricle was upregulated in myocarditis compared with normal rats (2.29 (1.42~3.40) for normal versus 4.18 (3.43~6.15) for myocarditis (median (range), average standard uptake value ratio against paraspinal muscle); n=6 per group, p-valuerats with cyclosporine-A treated myocarditis (3.69 (2.59~3.86) for myocarditis versus 2.28 (1.76~2.60) for cyclosporine-A treated myocarditis; n=6 per group, p-valueechocardiography. These results demonstrate the potential utility of visualizing infiltration of mannose receptor-positive macrophages with 68Ga-NOTA-MSA PET in the early diagnosis of as well as in the monitoring of treatment response of myocarditis. PMID:28042344

  10. Noninvasive Assessment of Gastric Emptying by Near-Infrared Fluorescence Reflectance Imaging in Mice: Pharmacological Validation with Tegaserod, Cisapride, and Clonidine

    Directory of Open Access Journals (Sweden)

    Hans-Ulrich Gremlich

    2004-10-01

    Full Text Available Noninvasive near-infrared fluorescence reflectance imaging (FRI is an in vivo technique to assess physiological and molecular processes in the intact organism. Here we describe a method to assess gastric emptying in mice. TentaGel™ beads with covalently bound cyanine dye (Cy5.5 conjugates as fluorescent probe were administered by oral gavage. The amount of intragastric beads/label was derived from the fluorescence signal intensity measured in a region of interest corresponding to the mouse stomach. The FRI signal intensity decreased as a function of time reflecting gastric emptying. In control mice, the gastric half-emptying time was in agreement with literature data. Pharmacological modulation of gastric motility allowed the evaluation of the sensitivity of the FRI-based method. Gastric emptying was either stimulated or inhibited by treatment with the 5-HT4 receptor agonists tegaserod (Zelnorm® and cisapride or the α2-receptor agonist clonidine, respectively. Tegaserod and cisapride dose-dependently accelerated gastric emptying. In contrast, clonidine dose-dependently delayed gastric emptying. In conclusion, FRI using fluorescently labeled beads allows the reliable determination of gastric emptying as well as the assessment of pharmacological interventions. The technique thus offers the potential to characterize molecular targets and pathways involved in physiological regulation and pharmacological modulation of gastric emptying.

  11. Non-invasive diagnosis in cerebral ischemia by means of magnetic resonance imaging and near-infrared spectroscopy; Nichtinvasive Diagnostik zerebraler Ischaemie mit Kernspintomographie und Nahe-Infrarotspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Piepgras, A. [Heidelberg Univ., Mannheim (Germany). Neurochirurgische Klinik; Gueckel, F. [Heidelberg Univ., Mannheim (Germany). Inst. fuer Klinische Radiologie; Laemmler, B. [Heidelberg Univ., Mannheim (Germany). Neurochirurgische Klinik; Weigel, R. [Heidelberg Univ., Mannheim (Germany). Neurochirurgische Klinik; Schmiedek, P. [Heidelberg Univ., Mannheim (Germany). Neurochirurgische Klinik

    1994-11-01

    We describe the non-invasive assessment of cerebrovascular reserve capacity by means of near-infrared spectroscopy (NIRS) and magnetic resonance imaging. Both methods are compared with transcranial Doppler sonography. There is a good correlation of the three methods in the changes in cerebral oxygen saturation and in blood velocity following acetazolamide stimulation of cerebral blood flow, except found in one patient with unilateral carotid artery occlusion. In this patient we found a decreased cerebrovascular reserve capacity, revealed by a magnetic resonance technique designed to quantify CBV and CBF. We postulate a raised oxygen extraction as raised oxygen extraction as the cause of his changes in oxygen saturation. (orig.) [Deutsch] Die Abschaetzung der zerebrovaskulaeren Reservekapazitaet unter Verwendung der Nahe-Infrarotspektroskopie und der Kernspintomographie zur nichtinvasiven klinischen Anwendung wird beschrieben. Beide Verfahren werden mit der transkraniellen Dopplersonographie verglichen. Bei Normalpersonen (n=3) zeigte sich eine gute Uebereinstimmung von Aenderungen der zerebralen Sauerstoffsaettigung mit Aenderungen der Blutflussgeschwindigkeit nach Acetazolamidstimulation der Hirndurchblutung. Diese Uebereinstimmung war bei einem Patienten mit kernspintomographisch nachgewiesener eingeschraenkter zerebrovaskulaerer Reservekapazitaet bei unilateralem Verschluss der A.carotis interna nicht gegeben. Dies wird auf eine pathologisch ehoehte Sauerstoffausschoepfung zurueeckgefuehrt. (orig.)

  12. Osteomyelitis: a review of currently used imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sammak, B.; Abd El Bagi, M; Al Shahed, M.; Al Nabulsi, J.; Youssef, B.; Al Thagafi, M. [Department of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Hamilton, D. [Department of Medical Physics, Riyadh Armed Forces Hospital (Saudi Arabia)

    1999-06-01

    Conventional radiographs remain the initial imaging modality involved in the diagnosis of osteomyelitis. Bone scintigraphy and its specific agents did not only eliminate the problems of inherent low sensitivity of conventional radiographs, but also increased the specificity to higher degrees. Spiral CT, on the other hand, has solved several diagnostic problems, such as osteomyelitis of the sterno-clavicular junction and hidden areas in the pelvic bones. Magnetic resonance imaging with its multiplanar capability, greater anatomic details and excellent soft tissue bone marrow contrast resolution has a significant role in surgical planning and limb preservation. Ultrasound and US-guided aspiration has recently been involved in the diagnosis and management of osteomyelitis with several advantages particularly in children. Our goal in this review is to outline the ability of various imaging techniques by comparing their strengths and weaknesses in the diagnosis of osteomyelitis. Finally, we suggest various imaging algorithms for specific clinical scenarios. Spondylitis and septic arthritis are not discussed in this review. (orig.) With 7 figs., 43 refs.

  13. Ultrasonic medical imaging: past, current, and future (Keynote Presentation)

    Science.gov (United States)

    Reid, John M.

    2005-04-01

    Ultrasonic imaging began, like life, in the sea, with the development of sonar for detecting submarines after World-War 1. However, to begin to image soft tissues the ranging time of ocean sonars needed to be reduced, and the electronics speeded up, by a factor of about the ratio between nautical miles and centimeters. This was only possible after the electronic developments made for radar in World-War 2. The rest of our technical history closely follows the developments in semiconductors and fabrication methods that led to modern electronics. This is a largely personal story of a recently graduated engineer with radar experience, who began with fabricating equipment to be used in the hospital to diagnose breast cancer, and continued with involvement the development of echocardiography and Doppler devices. Along the way many others have contributed to the field, including work in other countries that is not covered here. In future, ultrasonic imaging may hold the key to understanding some fundamental questions in human health if adopted for screening studies. It alone offers a relatively inexpensive imaging method that is free of known hazards.

  14. Spine imaging after lumbar disc replacement: pitfalls and current recommendations

    Directory of Open Access Journals (Sweden)

    Sandén Bengt

    2009-07-01

    Full Text Available Abstract Background Most lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI. Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures. Methods Possible complications of lumbar total disc replacement (TDR are reviewed from the available literature and imaging recommendations given with regard to implant type. Two illustrative cases are presented in figures. Results Access-related complications, infections, implant wear, loosening or fracture, polyethylene inlay dislodgement, facet joint hypertrophy, central stenosis, and ankylosis of the operated segment can be visualised both in titanium and stainless steel implants, but require different imaging modalities due to magnetic artifacts in MRI. Conclusion Alternative radiographic procedures should be considered when evaluating patients following TDR. Postoperative complications following lumbar TDR including spinal stenosis causing radiculopathy and implant loosening can be visualised by myelography and radionucleotide techniques as an adjunct to plain film radiographs. Even in the presence of massive stainless steel TDR implants lumbar radicular stenosis and implant loosening can be visualised if myelography and radionuclide techniques are applied.

  15. Ultrasound Current Source Density Imaging in live rabbit hearts using clinical intracardiac catheter

    Science.gov (United States)

    Li, Qian

    Ultrasound Current Source Density Imaging (UCSDI) is a noninvasive modality for mapping electrical activities in the body (brain and heart) in 4-dimensions (space + time). Conventional cardiac mapping technologies for guiding the radiofrequency ablation procedure for treatment of cardiac arrhythmias have certain limitations. UCSDI can potentially overcome these limitations and enhance the electrophysiology mapping of the heart. UCSDI exploits the acoustoelectric (AE) effect, an interaction between ultrasound pressure and electrical resistivity. When an ultrasound beam intersects a current path in a material, the local resistivity of the material is modulated by the ultrasonic pressure, and a change in voltage signal can be detected based on Ohm's Law. The degree of modulation is determined by the AE interaction constant K. K is a fundamental property of any type of material, and directly affects the amplitude of the AE signal detected in UCSDI. UCSDI requires detecting a small AE signal associated with electrocardiogram. So sensitivity becomes a major challenge for transferring UCSDI to the clinic. This dissertation will determine the limits of sensitivity and resolution for UCSDI, balancing the tradeoff between them by finding the optimal parameters for electrical cardiac mapping, and finally test the optimized system in a realistic setting. This work begins by describing a technique for measuring K, the AE interaction constant, in ionic solution and biological tissue, and reporting the value of K in excised rabbit cardiac tissue for the first time. K was found to be strongly dependent on concentration for the divalent salt CuSO4, but not for the monovalent salt NaCl, consistent with their different chemical properties. In the rabbit heart tissue, K was determined to be 0.041 +/- 0.012 %/MPa, similar to the measurement of K in physiologic saline: 0.034 +/- 0.003 %/MPa. Next, this dissertation investigates the sensitivity limit of UCSDI by quantifying the relation

  16. Imaging of activated complement using ultrasmall superparamagnetic iron oxide particles (USPIO) - conjugated vectors: an in vivo in utero non-invasive method to predict placental insufficiency and abnormal fetal brain development

    Science.gov (United States)

    Girardi, G; Fraser, J; Lennen, R; Vontell, R; Jansen, M; Hutchison, G

    2015-01-01

    In the current study, we have developed a magnetic resonance imaging-based method for non-invasive detection of complement activation in placenta and foetal brain in vivo in utero. Using this method, we found that anti-complement C3-targeted ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles bind within the inflamed placenta and foetal brain cortical tissue, causing a shortening of the T2* relaxation time. We used two mouse models of pregnancy complications: a mouse model of obstetrics antiphospholipid syndrome (APS) and a mouse model of preterm birth (PTB). We found that detection of C3 deposition in the placenta in the APS model was associated with placental insufficiency characterised by increased oxidative stress, decreased vascular endothelial growth factor and placental growth factor levels and intrauterine growth restriction. We also found that foetal brain C3 deposition was associated with cortical axonal cytoarchitecture disruption and increased neurodegeneration in the mouse model of APS and in the PTB model. In the APS model, foetuses that showed increased C3 in their brains additionally expressed anxiety-related behaviour after birth. Importantly, USPIO did not affect pregnancy outcomes and liver function in the mother and the offspring, suggesting that this method may be useful for detecting complement activation in vivo in utero and predicting placental insufficiency and abnormal foetal neurodevelopment that leads to neuropsychiatric disorders. PMID:25245499

  17. A new in vivo magnetic resonance imaging method to noninvasively monitor and quantify the perfusion capacity of three-dimensional biomaterials grown on the chorioallantoic membrane of chick embryos.

    Science.gov (United States)

    Kivrak Pfiffner, Fatma; Waschkies, Conny; Tian, Yinghua; Woloszyk, Anna; Calcagni, Maurizio; Giovanoli, Pietro; Rudin, Markus; Buschmann, Johanna

    2015-04-01

    Adequate vascularization in biomaterials is essential for tissue regeneration and repair. Current models do not allow easy analysis of vascularization of implants in vivo, leaving it a highly desirable goal. A tool that allows monitoring of perfusion capacity of such biomaterials noninvasively in a cheap, efficient, and reliable in vivo model would hence add great benefit to research in this field. We established, for the first time, an in vivo magnetic resonance imaging (MRI) method to quantify the perfusion capacity of a model biomaterial, DegraPol(®) foam scaffold, placed on the embryonic avian chorioallantoic membrane (CAM) in ovo. Perfusion capacity was assessed through changes in the longitudinal relaxation rate before and after injection of a paramagnetic MRI contrast agent, Gd-DOTA (Dotarem(®); Guerbet S.A.). Relaxation rate changes were compared in three different regions of the scaffold, that is, at the interface to the CAM, in the middle and on the surface of the scaffold (pdental pulp stem cells. For these, three to four times larger perfusion capacities were obtained compared to DegraPol; demonstrating that our method is sensitive to reveal such differences. In summary, we present a novel in vivo method for analyzing the perfusion capacity in three-dimensional-biomaterials grown on the CAM, enabling the determination of the perfusion capacity of a large variety of bioengineered materials.

  18. The Role of Noninvasive Techniques in Stroke Therapy

    Directory of Open Access Journals (Sweden)

    Daniel Maxwell Bernad

    2008-01-01

    Full Text Available Noninvasive techniques such as functional magnetic resonance imaging (fMRI and transcranial magnetic stimulation (TMS have provided insight into understanding how neural connections are altered in consequence to cerebrovascular injury. The first part of this review will briefly survey some of the methodological issues and limitations related to noninvasive poststroke motor recovery studies. The second section will investigate some of the different neural mechanisms that underlie neurorehabilitation in stroke patients. The third part will explore our current understanding of motor memory processing, describe the neural structures that subserve motor memory consolidation, and discuss the current literature related to memory reconsolidation in healthy adults. Lastly, this paper will suggest the potential therapeutic applications of integrating noninvasive tools with memory consolidation and reconsolidation theories to enhance motor recovery. The overall objective of this work is to demonstrate how noninvasive technologies have been utilized in the multidisciplinary field of clinical behavioral neuroscience and to highlight their potential to be employed as clinical tools to promote individualized motor recovery in stroke patients.

  19. Histone deacetylase inhibition increases levels of choline kinase alpha and phosphocholine facilitating non-invasive imaging in human cancers

    OpenAIRE

    2011-01-01

    Histone deacetylase (HDAC) inhibitors are currently approved for cutaneous T-cell lymphoma and are in mid-late stage trials for other cancers. The HDAC inhibitors LAQ824 and SAHA increase phosphocholine (PC) levels in human colon cancer cells and tumor xenografts as observed by magnetic resonance spectroscopy (MRS). In this study, we show that belinostat, an HDAC inhibitor with an alternative chemical scaffold, also caused a rise in cellular PC content that was detectable by 1H and 31P MRS in...

  20. Current Density Imaging through Acoustically Encoded Magnetometry: A Theoretical Exploration

    CERN Document Server

    Sheltraw, Daniel J

    2014-01-01

    The problem of determining a current density confined to a volume from measurements of the magnetic field it produces exterior to that volume is known to have non-unique solutions. To uniquely determine the current density, or the non-silent components of it, additional spatial encoding of the electric current is needed. In biological systems such as the brain and heart, which generate electric current associated with normal function, a reliable means of generating such additional encoding, on a spatial and temporal scale meaningful to the study of such systems, would be a boon for research. This paper explores a speculative method by which the required additional encoding might be accomplished, on the time scale associated with the propagation of sound across the volume of interest, by means of the application of a radially encoding pulsed acoustic spherical wave.

  1. First-in-Man Analysis of the Relationship Between Electrical Rotors From Noninvasive Panoramic Mapping and Atrial Fibrosis From Magnetic Resonance Imaging in Patients With Persistent Atrial Fibrillation.

    Science.gov (United States)

    Sohns, Christian; Lemes, Christine; Metzner, Andreas; Fink, Thomas; Chmelevsky, Mikhail; Maurer, Tilman; Budanova, Margarita; Solntsev, Vladislav; Schulze, Walther H W; Staab, Wieland; Mathew, Shibu; Heeger, Christian; Reißmann, Bruno; Kholmovski, Eugene; Kivelitz, Dietmar; Ouyang, Feifan; Kuck, Karl-Heinz

    2017-08-01

    Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to evaluate characteristics of atrial fibrosis. The novel noninvasive epicardial and endocardial electrophysiology system (NEEES) allows for the identification of sources with rotor activity. This study describes a new technique to examine the relationship between rotors and LGE signal intensity in patients with persistent atrial fibrillation (PERS) scheduled for ablation. Ten consecutive patients underwent pulmonary vein isolation for persistent atrial fibrillation. LGE CMR of both atria was performed, and NEEES-based analysis was conducted to identify rotors. For each mapping point, the intracardiac locations were transferred onto an individual CMR-derived 3-dimensional shell. This allowed the LGE signal intensity to be projected onto the anatomy from the NEEES analysis. NEEES analysis identified a total number of 410 electric rotors, 47.8% were located in the left atrium and 52.2% in the right atrium. Magnetic resonance imaging analysis was performed from 10 right atria and 10 left atria data sets, including 86 axial LGE CMR planes per atrium. The mean LGE burden for left atrium and right atrium was 23.9±1.6% and 15.9±1.8%, respectively. Statistical analysis demonstrated a lack of regional association between the extent of LGE signal intensity and the presence of rotors. This is the first study demonstrating that the presence of rotors based on NEEES analysis is not directly associated with the extent and anatomic location of LGE signal intensity from CMR. Further studies evaluating the relationship between rotors and fibrosis in patients with persistent atrial fibrillation are mandatory and may inform strategies to improve ablation outcome. © 2017 American Heart Association, Inc.

  2. Monitoring therapeutic response of human ovarian cancer to 17-DMAG by noninvasive PET imaging with {sup 64}Cu-DOTA-trastuzumab

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Gang; Cao, Qizhen; Chen, Xiaoyuan [Stanford University School of Medicine, The Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford, CA (United States); Li, Zibo [Stanford University School of Medicine, The Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford, CA (United States); Keck School of Medicine, USC Molecular Imaging Center, Department of Radiology, Los Angeles, CA (United States)

    2009-09-15

    17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), a heat-shock protein 90 (Hsp90) inhibitor, has been intensively investigated for cancer therapy and is undergoing clinical trials. Human epidermal growth factor receptor 2 (HER-2) is one of the client proteins of Hsp90 and its expression is decreased upon 17-DMAG treatment. In this study, we aimed to noninvasively monitor the HER-2 response to 17-DMAG treatment in xenografted mice. The sensitivity of human ovarian cancer SKOV-3 cells to 17-DMAG in vitro was measured by MTT assay. HER-2 expression in SKOV-3 cells was determined by flow cytometry. Nude mice bearing SKOV-3 tumors were treated with 17-DMAG and the therapeutic efficacy was evaluated by tumor size measurement. Both treated and control mice were imaged with microPET using {sup 64}Cu-DOTA-trastuzumab and {sup 18}F-FDG. Biodistribution studies and immunofluorescence staining were performed to validate the microPET results. SKOV-3 cells are sensitive to 17-DMAG treatment, in a dose-dependent manner, with an IC{sub 50} value of 24.72 nM after 72 h incubation. The tumor growth curve supported the inhibition effect of 17-DMAG on SKOV-3 tumors. Quantitative microPET imaging showed that {sup 64}Cu-DOTA-trastuzumab had prominent tumor accumulation in untreated SKOV-3 tumors, which was significantly reduced in 17-DMAG-treated tumors. There was no uptake difference detected by FDG PET. Immunofluorescence staining confirmed the significant reduction in tumor HER-2 level upon 17-DMAG treatment. The early response to anti-Hsp90 therapy was successfully monitored by quantitative PET using {sup 64}Cu-DOTA-trastuzumab. This approach may be valuable in monitoring the therapeutic response in HER-2-positive cancer patients under 17-DMAG treatment. (orig.)

  3. Noninvasive cardiac risk stratification of diabetic and nondiabetic uremic renal allograft candidates using dipyridamole-thallium-201 imaging and radionuclide ventriculography

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.A.; Rimmer, J.; Haisch, C. (Univ. of Vermont College of Medicine, Burlington (USA))

    1989-11-01

    The ability of noninvasive risk stratification using dipyridamole-thallium-201 (Tl-201) imaging and radionuclide ventriculography to predict perioperative and long-term cardiac events (myocardial infarction or cardiac death) was evaluated in 36 uremic diabetic and 29 nondiabetic candidates for renal allograft surgery. Of the 35 patients who underwent renal allograft surgery 8 +/- 7 months after the study, none had transient Tl-201 defects (although 13 had depressed left ventricular ejection fraction) and none developed perioperative cardiac events. During a mean follow-up of 23 +/- 11 months, 6 (9%) patients developed cardiac events. Logistic regression analysis was used to compare the predictive value of clinical data (including age, sex, diabetes, chest pain history, allograft recipient) and radionuclide data. Presence of transient Tl-201 defect and left ventricular ejection fraction were the only significant predictors of future cardiac events (p less than 0.01). No other patient variables, including diabetes or receiving a renal allograft, had either univariate or multivariate predictive value. All 3 patients with transient Tl-201 defects had cardiac events compared with only 3 of 62 (5%) patients without transient Tl-201 defect (p less than 0.0001). Mean left ventricular ejection fraction was lower in patients with cardiac events (44 +/- 13%) compared with patients without cardiac events (57 +/- 9%, p less than 0.005). Overall, 5 of 6 patients with cardiac events had either transient Tl-201 defects or depressed left ventricular ejection fraction. Dipyridamole-Tl-201 imaging and radionuclide ventriculography may be helpful in identifying uremic candidates for renal allograft surgery who are at low risk for perioperative and long-term cardiac events.

  4. Noninvasive cross-sectional imaging of proximal caries using swept-source optical coherence tomography (SS-OCT) in vivo.

    Science.gov (United States)

    Shimada, Yasushi; Nakagawa, Hisaichi; Sadr, Alireza; Wada, Ikumi; Nakajima, Masatoshi; Nikaido, Toru; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2014-07-01

    The aim of this study was to determine the diagnostic accuracy of swept-source optical coherent tomography (SS-OCT) in detecting and estimating the depth of proximal caries in posterior teeth in vivo. SS-OCT images and bitewing radiographs were obtained from 86 proximal surfaces of 53 patients. Six examiners scored the locations according to a caries lesion depth scale (0-4) using SS-OCT and the radiographs. The results were compared with clinical observations obtained after the treatment. SS-OCT could detect the presence of proximal caries in tomograms that were synthesized based on the backscatter signal obtained from the proximal carious lesion through occlusal enamel. SS-OCT showed significantly higher sensitivity and larger area under the receiver operating characteristic curve than radiographs for the detection of cavitated enamel lesions and dentin caries (Student's t -test, p SS-OCT appears to be a more reliable and accurate method than bitewing radiographs for the detection and estimation of the depth of proximal lesions in the clinical environment.

  5. A pH-activatable nanoparticle with signal-amplification capabilities for non-invasive imaging of tumour malignancy

    Science.gov (United States)

    Mi, Peng; Kokuryo, Daisuke; Cabral, Horacio; Wu, Hailiang; Terada, Yasuko; Saga, Tsuneo; Aoki, Ichio; Nishiyama, Nobuhiro; Kataoka, Kazunori

    2016-08-01

    Engineered nanoparticles that respond to pathophysiological parameters, such as pH or redox potential, have been developed as contrast agents for the magnetic resonance imaging (MRI) of tumours. However, beyond anatomic assessment, contrast agents that can sense these pathological parameters and rapidly amplify their magnetic resonance signals are desirable because they could potentially be used to monitor the biological processes of tumours and improve cancer diagnosis. Here, we report an MRI contrast agent that rapidly amplifies magnetic resonance signals in response to pH. We confined Mn2+ within pH-sensitive calcium phosphate (CaP) nanoparticles comprising a poly(ethylene glycol) shell. At a low pH, such as in solid tumours, the CaP disintegrates and releases Mn2+ ions. Binding to proteins increases the relaxivity of Mn2+ and enhances the contrast. We show that these nanoparticles could rapidly and selectively brighten solid tumours, identify hypoxic regions within the tumour mass and detect invisible millimetre-sized metastatic tumours in the liver.

  6. Noninvasive evaluation of global and regional left ventricular function using computed tomography and magnetic resonance imaging: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kaniewska, Malwina; Schuetz, Georg M.; Willun, Steffen; Dewey, Marc [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Schlattmann, Peter [Jena University Hospital, Department of Medical Statistics, Informatics and Documentation, Jena (Germany)

    2017-04-15

    To compare the diagnostic accuracy of computed tomography (CT) in the assessment of global and regional left ventricular (LV) function with magnetic resonance imaging (MRI). MEDLINE, EMBASE and ISI Web of Science were systematically reviewed. Evaluation included: ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and left ventricular mass (LVM). Differences between modalities were analysed using limits of agreement (LoA). Publication bias was measured by Egger's regression test. Heterogeneity was evaluated using Cochran's Q test and Higgins I{sup 2} statistic. In the presence of heterogeneity the DerSimonian-Laird method was used for estimation of heterogeneity variance. Fifty-three studies including 1,814 patients were identified. The mean difference between CT and MRI was -0.56 % (LoA, -11.6-10.5 %) for EF, 2.62 ml (-34.1-39.3 ml) for EDV and 1.61 ml (-22.4-25.7 ml) for ESV, 3.21 ml (-21.8-28.3 ml) for SV and 0.13 g (-28.2-28.4 g) for LVM. CT detected wall motion abnormalities on a per-segment basis with 90 % sensitivity and 97 % specificity. CT is accurate for assessing global LV function parameters but the limits of agreement versus MRI are moderately wide, while wall motion deficits are detected with high accuracy. (orig.)

  7. Earliest Detection of Oral Cancer Using Non-Invasive Brush Biopsy Including DNA-Image-Cytometry: Report on Four Cases

    Directory of Open Access Journals (Sweden)

    Torsten W. Remmerbach

    2003-01-01

    Full Text Available Objective: We describe four patients presenting early oral cancers, detected cytologically on non‐invasive brush biopsies including DNA‐image cytometry as an adjunctive method before histology on scalpel biopsies confirmed the evidence of malignancy. Methods: Brush biopsies were performed and smears thereof investigated cytologically. After Feulgen restaining, DNA‐measurements were performed using a DNA‐Image‐Cytometer. Case reports: Oral squamous cell carcinomas were diagnosed cytologically in macroscopically suspicious lesions and malignancy confirmed by DNA‐cytometry. The initially performed scalpel biopsies did neither supply evidence of oral cancer nor of severe dysplasia. After at least one to 15 months the occurrence of cancer was finally proven histologically on a second scalpel biopsy each (three microinvasive and one in situ carcinoma. Conclusion: Non‐invasive brush biopsies are a suitable instrument for early cytologic detection of cancer of the mouth. DNA‐image‐cytometry, as an adjunctive method, can be used to confirm the cytologic diagnosis or suspicion of cancer in patients with doubtful lesions (dysplasias. DNA‐aneuploidy is a marker for (prospective malignancy in smears of the oral cavity, which may detect malignancy months prior to histology. In future this method could be used as a mass screening tool in dentists practise. Colour figures can be viewed on http://www.esacp.org/acp/2003/25‐4/remmerbach.htm.

  8. Pheochromocytoma and Paraganglioma: Current Functional and Future Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Elise M Blanchet

    2012-01-01

    Full Text Available Paragangliomas are neural crest-derived tumors, arising either from chromaffin sympathetic tissue (in adrenal, abdominal, intra-pelvic or thoracic paraganglia or from parasympathetic tissue (in head and neck paraganglia. They have a specific cellular metabolism, with the ability to synthesize, store and secrete catecholamines (although most head and neck paragangliomas do not secrete any catecholamines. This disease is rare and also very heterogeneous, with various presentations (e.g., in regards to localization, multifocality, potential to metastasize, biochemical phenotype, and genetic background. With growing knowledge, notably about the pathophysiology and genetic background, guidelines are evolving rapidly. In this context, functional imaging is a challenge for the management of paragangliomas.Nuclear imaging has been used for exploring paragangliomas for the last three decades, with MIBG historically as the first-line exam. Tracers used in paragangliomas can be grouped in three different categories. Agents that specifically target catecholamine synthesis, storage, and secretion pathways include: 123 and 131I-metaiodobenzylguanidine (123/131I-MIBG, 18F-fluorodopamine (18F-FDA, and 18F-fluorodihydroxyphenylalanine (18F-FDOPA. Agents that bind somatostatin receptors include 111In-pentetreotide and 68Ga-labelled somatostatin analog peptides. The non-specific agent most commonly used in paragangliomas is 18F-fluorodeoxyglucose (18F-FDG. This review will first describe conventional scintigraphic exams that are used for imaging paragangliomas. In the second part we will emphasize the interest in new PET approaches (specific and non-specific, considering the growing knowledge about genetic background and pathophysiology, with the aim of understanding how tumors behave, and optimally adjusting imaging technique for each tumor type.

  9. Amyloid plaque imaging in vivo: current achievement and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Agneta [Karolinska University Hospital Huddinge, Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Alzheimer Neurobiology, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Geriatric Medicine, Stockholm (Sweden)

    2008-03-15

    Alzheimer's disease (AD) is a very complex neurodegenerative disorder, the exact cause of which is still not known. The major histopathological features, amyloid plaques and neurofibrillary tangles, already described by Alois Alzheimer, have been the focus in research for decades. Despite a probable whole cascade of events in the brain leading to impairment of cognition, amyloid is still the target for diagnosis and treatment. The rapid development of molecular imaging techniques now allows imaging of amyloid plaques in vivo in Alzheimer patients by PET amyloid ligands such as Pittsburgh compound B (PIB). Studies so far have revealed high {sup 11}C-PIB retention in brain at prodromal stages of AD and a possibility to discriminate AD from other dementia disorders by {sup 11}C-PIB. Ongoing studies are focussing to understand the relationship between brain and CSF amyloid processes and cognitive processes. In vivo imaging of amyloid will be important for early diagnosis and evaluation of new anti-amyloid therapies in AD. (orig.)

  10. Non-invasive evaluation of neuroprotective drug candidates for cerebral infarction by PET imaging of mitochondrial complex-I activity

    Science.gov (United States)

    Fukuta, Tatsuya; Asai, Tomohiro; Ishii, Takayuki; Koide, Hiroyuki; Kiyokawa, Chiaki; Hashimoto, Masahiro; Kikuchi, Takashi; Shimizu, Kosuke; Harada, Norihiro; Tsukada, Hideo; Oku, Naoto

    2016-07-01

    The development of a diagnostic technology that can accurately determine the pathological progression of ischemic stroke and evaluate the therapeutic effects of cerebroprotective agents has been desired. We previously developed a novel PET probe, 2-tert-butyl-4-chloro-5-{6-[2-(2-18F-fluoroethoxy)-ethoxy]-pyridin-3-ylmethoxy}-2H-pyridazin-3-one ([18F]BCPP-EF) for detecting activity of mitochondrial complex I (MC-I). This probe was shown to visualize neuronal damage in the living brain of rodent and primate models of neurodegenerative diseases. In the present study, [18F]BCPP-EF was applied to evaluate the therapeutic effects of a neuroprotectant, liposomal FK506 (FK506-liposomes), on cerebral ischemia/reperfusion (I/R) injury in transient middle cerebral artery occlusion rats. The PET imaging using [18F]BCPP-EF showed a prominent reduction in the MC-I activity in the ischemic brain hemisphere. Treatment with FK506-liposomes remarkably increased the uptake of [18F]BCPP-EF in the ischemic side corresponding to the improvement of blood flow disorders and motor function deficits throughout the 7 days after I/R. Additionally, the PET scan could diagnose the extent of the brain damage accurately and showed the neuroprotective effect of FK506-liposomes at Day 7, at which 2, 3, 5-triphenyltetrazolium chloride staining couldn’t visualize them. Our study demonstrated that the PET technology using [18F]BCPP-EF has a potent capacity to evaluate the therapeutic effect of drug candidates in living brain.

  11. Correlation of liver density by magnetic resonance imaging and hepatic iron levels. A noninvasive means to exclude homozygous hemochromatosis.

    Science.gov (United States)

    Lawrence, S P; Caminer, S J; Yavorski, R T; Borosky, B D; Rak, K M; Merenich, J A; McDermott, M T; McNally, P R

    1996-09-01

    The diagnosis of hemochromatosis requires liver biopsy and the quantification of hepatic iron. Magnetic resonance imaging (MRI) of the liver shows a characteristic decrease in tissue signal intensity in iron overload states, but its role in the diagnosis of hemochromatosis has not been fully delineated. Forty-three patients (31 men and 12 women) were referred for the evaluation of hemochromatosis based upon a fasting transferrin saturation > 55% and/or a serum ferritin > 400 ng/ml in males or > 300 ng/ml in females. Each patient prospectively underwent MRI of the liver prior to percutaneous liver biopsy and quantitative hepatic iron determination. Homozygous hemochromatosis was diagnosed in 10 patients based upon an hepatic iron/age index > or = 2. MRI was performed with a 1.5 Tesla system using standard spin-echo sequences (T1; TR = 300-500 ms, TE = 13-17 ms, PD; TR = 2,000-2,600 ms, TE = 30 ms). Signal intensity values were blindly determined for regions of interest in liver and skeletal muscle at T1 and proton density. Ratios of liver to muscle (LM) for T1 and proton density (PD) calculated from these values showed a significant correlation with quantitative iron by multiple regression analysis. The LMPD ratio provided the best correlation with hepatic iron (r = -0.6946; p 0.5 had hepatic iron/age indices of < 2.0, thereby excluding homozygous hemochromatosis. These results suggest that LMPD ratios derived from MRI of the liver can accurately predict hepatic iron content. These ratios can be clinically useful in the evaluation of hemochromatosis among patients who either refuse or have contraindications to liver biopsy.

  12. Noninvasive evaluation of global and regional left ventricular function using computed tomography and magnetic resonance imaging: a meta-analysis.

    Science.gov (United States)

    Kaniewska, Malwina; Schuetz, Georg M; Willun, Steffen; Schlattmann, Peter; Dewey, Marc

    2017-04-01

    To compare the diagnostic accuracy of computed tomography (CT) in the assessment of global and regional left ventricular (LV) function with magnetic resonance imaging (MRI). MEDLINE, EMBASE and ISI Web of Science were systematically reviewed. Evaluation included: ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and left ventricular mass (LVM). Differences between modalities were analysed using limits of agreement (LoA). Publication bias was measured by Egger's regression test. Heterogeneity was evaluated using Cochran's Q test and Higgins I(2) statistic. In the presence of heterogeneity the DerSimonian-Laird method was used for estimation of heterogeneity variance. Fifty-three studies including 1,814 patients were identified. The mean difference between CT and MRI was -0.56 % (LoA, -11.6-10.5 %) for EF, 2.62 ml (-34.1-39.3 ml) for EDV and 1.61 ml (-22.4-25.7 ml) for ESV, 3.21 ml (-21.8-28.3 ml) for SV and 0.13 g (-28.2-28.4 g) for LVM. CT detected wall motion abnormalities on a per-segment basis with 90 % sensitivity and 97 % specificity. CT is accurate for assessing global LV function parameters but the limits of agreement versus MRI are moderately wide, while wall motion deficits are detected with high accuracy. • CT helps to assess patients with coronary artery disease (CAD). • MRI is the reference standard for evaluation of left ventricular function. • CT provides accurate assessment of global left ventricular function.

  13. Investigation of oncogenic cooperation in simple liver-specific transgenic mouse models using noninvasive in vivo imaging.

    Directory of Open Access Journals (Sweden)

    Hye-Lim Ju

    Full Text Available Liver cancer is a complex multistep process requiring genetic alterations in multiple proto-oncogenes and tumor suppressor genes. Although hundreds of genes are known to play roles in hepatocarcinogenesis, oncogenic collaboration among these genes is still largely unknown. Here, we report a simple methodology by which oncogenic cooperation between cancer-related genes can be efficiently investigated in the liver. We developed various non-germline transgenic mouse models using hydrodynamics-based transfection which express HrasG12V, SmoM2, and a short-hairpin RNA down-regulating p53 (shp53 individually or in combination in the liver. In this transgenic system, firefly luciferase was co-expressed with the oncogenes as a reporter, allowing tumor growth in the liver to be monitored over time without an invasive procedure. Very strong bioluminescence imaging (BLI signals were observed at 4 weeks post-hydrodynamic injection (PHI in mice co-expressing HrasG12V and shp53, while only background signals were detected in other double or single transgenic groups until 30 weeks PHI. Consistent with the BLI data, tumors were observed in the HrasG12V plus shp53 group at 4 weeks PHI, while other transgenic groups failed to exhibit a hyperplastic nodule at 30 weeks PHI. In the HrasG12V plus shp53 transgenic group, BLI signals were well-correlated with actual tumor growth in the liver, confirming the versatility of BLI-based monitoring of tumor growth in this organ. The methodology described here is expected to accelerate and facilitate in vivo studies of the hepatocarcinogenic potential of cancer-related genes by means of oncogenic cooperation.

  14. In vivo quantification of VCAM-1 expression in renal ischemia reperfusion injury using non-invasive magnetic resonance molecular imaging.

    Directory of Open Access Journals (Sweden)

    Asim M Akhtar

    Full Text Available RATIONALE AND OBJECTIVE: Vascular cell adhesion molecule-1 (VCAM-1 is upregulated in ischemia reperfusion injury (IRI, persisting after restoration of blood flow. We hypothesized that microparticles of iron oxide targeting VCAM-1 (VCAM-MPIO would depict "ischemic memory" and enable in vivo assessment of VCAM-1 expression. METHODOLOGY AND FINDINGS: Mice subject to unilateral, transient (30 minutes renal ischemia and subsequent reperfusion received intravenous VCAM-MPIO (4.5 mg iron/kg body weight. Contrast agent bound rapidly (<30 minutes in IRI-kidneys and appeared as intensely low signal areas by MRI in vivo. Automated segmentation and quantification yielded MPIO contrast volumes of 5991±354×10(6 µm(3 in IRI vs. 87±7×10(6 µm(3 in kidneys with no surgical intervention (P<0.001; 90±8×10(6 µm(3 in IRI kidneys exposed to control (IgG-MPIO and 625±80×10(6 µm(3, in IRI kidneys pre-treated with a blocking dose of VCAM-1 antibody (P<0.001. In keeping with quantitative MRI data, VCAM-1 mRNA expression in IRI was 65-fold higher than in kidneys without surgical intervention (3.06±0.63 vs. 0.05±0.02, P<0.001. Indeed VCAM-1 mRNA expression and VCAM-MPIO contrast volume were highly correlated (R(2=0.901, P<0.01, indicating that quantification of contrast volume reflected renal VCAM-1 transcription. Serial imaging showed VCAM-MPIO accumulation at target within 30 minutes, persisting for ≥90 minutes, while unbound VCAM-MPIO was cleared rapidly from blood, with sequestration by mac-3 positive Kupffer cells in the liver and monocyte/macrophages in the spleen. CONCLUSIONS: (1 VCAM-MPIO detected VCAM-1 expression and defined its 3-dimensional distribution, revealing "ischemic memory" in renal IRI; (2 automated volumetric quantification of VCAM-MPIO accurately reflected tissue levels of VCAM-1 mRNA; and (3 VCAM-MPIO bound rapidly to target with active sequestration of unbound MPIO in the liver and spleen.

  15. Fetal imaging and therapy for CDH-Current status.

    Science.gov (United States)

    Oluyomi-Obi, Titilayo; Van Mieghem, Tim; Ryan, Greg

    2017-06-01

    In congenital diaphragmatic hernia (CDH), herniation of the abdominal organs into the fetal chest causes pulmonary hypoplasia and pulmonary hypertension, the main causes of neonatal mortality. As antenatal ultrasound screening improves, the risk of postnatal death can now be better predicted, allowing for the identification of fetuses that might most benefit from a prenatal intervention. Fetoscopic tracheal occlusion is being evaluated in a large international randomized controlled trial. We present the antenatal imaging approaches that can help identify fetuses that might benefit from antenatal therapy, and review the evolution of fetal surgery for CDH to date. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The current state and future of fetal imaging.

    Science.gov (United States)

    Chung, Romy; Kasprian, Gregor; Brugger, Peter C; Prayer, Daniela

    2009-09-01

    Fetal magnetic resonance imaging (MRI) may add important diagnostic information to prenatal sonography and has the power to confirm or change decisions at critical points in clinical care. Recent studies have shown MRI to be a critical clinical adjunct in the evaluation of the developing central nervous system (CNS), especially at early gestational ages, and MRI has been used in three significant ways: (1) for the quantification of brain growth and structural abnormalities using biometry, (2) for the qualitative evaluation of CNS microstructure, and (3) for the qualitative assessment of dynamic fetal movements in utero.

  17. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma

    OpenAIRE

    Mohindroo, Chirayu; Ichhpujani, Parul; Kumar, Suresh

    2016-01-01

    Glaucoma may be caused by an interplay of elevated intraocular pressure (IOP), vascular, genetic, anatomical, brain, and immune factors. The direct assessment of ocular hemodynam-ics offers promise for glaucoma detection, differentiation, and possibly new treatment modalities. All the methods currently in use to measure ocular blood flow have inherent limitations and measure different aspects of ocular blood flow. This review article attempts to provide detailed information on ocular perfu-si...

  18. Pectus excavatum: current imaging techniques and opportunities for dose reduction.

    Science.gov (United States)

    Sarwar, Zahir U; DeFlorio, Robert; O'Connor, Stephen C

    2014-08-01

    Pectus excavatum (PE) is the most common congenital chest wall deformity in children. It affects 1 in every 300-1000 live births with a male to female ratio of 5:1. Most of the patients present in their first year of life. During the teenage years, patients may have exercise intolerance and psychological strain because of their chest wall deformity. The Nuss and Ravitch procedures are established methods of surgical correction of PE. An index of severity known best as the Haller index, typically evaluated with computed tomography scan, when measuring greater than 3.2 is considered to indicate moderate or severe PE and is a prerequisite for third-party insurance reimbursement for these corrective procedures. This article reviews the clinical features of PE, the role of imaging, and the opportunities for radiation dose reduction.

  19. An open source image processing method to quantitatively assess tissue growth after non-invasive magnetic resonance imaging in human bone marrow stromal cell seeded 3D polymeric scaffolds.

    Science.gov (United States)

    Leferink, Anne M; Fratila, Raluca M; Koenrades, Maaike A; van Blitterswijk, Clemens A; Velders, Aldrik; Moroni, Lorenzo

    2014-01-01

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional (3D) scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs) are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI) is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs.

  20. An open source image processing method to quantitatively assess tissue growth after non-invasive magnetic resonance imaging in human bone marrow stromal cell seeded 3D polymeric scaffolds.

    Directory of Open Access Journals (Sweden)

    Anne M Leferink

    Full Text Available Monitoring extracellular matrix (ECM components is one of the key methods used to determine tissue quality in three-dimensional (3D scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate-poly(butylene terephthalate (PEOT/PBT scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs.

  1. Potential of time series-hyperspectral imaging (TS-HSI) for non-invasive determination of microbial spoilage of salmon flesh.

    Science.gov (United States)

    Wu, Di; Sun, Da-Wen

    2013-07-15

    This study investigated the potential of using time series-hyperspectral imaging (TS-HSI) in visible and near infrared region (400-1700 nm) for rapid and non-invasive determination of surface total viable count (TVC) of salmon flesh during spoilage process. Hyperspectral cubes were acquired at different spoilage stages for salmon chops and their spectral data were extracted. The reference TVC values of the same samples were measured using standard plate count method and then calibrated with their corresponding spectral data based on two calibration methods of partial least square regression (PLSR) and least-squares support vector machines (LS-SVM), respectively. Competitive adaptive reweighted sampling (CARS) was conducted to identify the most important wavelengths/variables that had the greatest influence on the TVC prediction throughout the whole wavelength range. As a result, eight variables representing the wavelengths of 495 nm, 535 nm, 550 nm, 585 nm, 625 nm, 660 nm, 785 nm, and 915 nm were selected, which were used to reduce the high dimensionality of the hyperspectral data. On the basis of the selected variables, the models of PLSR and LS-SVM were established and their performances were compared. The CARS-PLSR model established using Spectral Set I (400-1000 nm) was considered to be the best for the TVC determination of salmon flesh. The model led to a coefficient of determination (rP(2)) of 0.985 and residual predictive deviation (RPD) of 5.127. At last, the best model was used to predict the TVC values of each pixel within the ROI of salmon chops for visualizing the TVC distribution of salmon flesh. The research demonstrated that TS-HSI technique has a potential for rapid and non-destructive determination of bacterial spoilage in salmon flesh during the spoilage process.

  2. CFD Modeling and Image Analysis of Exhaled Aerosols due to a Growing Bronchial Tumor: towards Non-Invasive Diagnosis and Treatment of Respiratory Obstructive Diseases

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.; Corley, Richard A.; Kabilan, Senthil; Wang, Shengyu

    2015-02-06

    Diagnosis and prognosis of tumorigenesis are generally performed with CT, PET, or biopsy. Such methods are accurate, but have the limitations of high cost and posing additional health risks to patients. In this study, we introduce an alternative computer aided diagnostic tool that can locate malignant sites caused by tumorigenesis in a non-invasive and low-cost way. Our hypothesis is that exhaled aerosol distribution is unique to lung structure and is sensitive to airway structure vari-ations. With appropriate approaches, it is possible to locate the disease site, determine the disease severity, and subsequently formulate a targeted drug delivery plan to treat the disease. This study numerically evaluated the feasibility of the proposed breath test in an image-based lung model with varying pathological stages of a bronchial squamous tumor. Large eddy simulations and a Lagran-gian tracking approach were used to model respiratory airflows and aerosol dynamics. Respira-tions of tracer aerosols of 1 µm at a flow rate of 20 L/min were simulated, with the distributions of exhaled aerosols recorded on a filter at the mouth exit. Aerosol patterns were quantified with multiple analytical techniques such as concentration disparity, spatial scanning and fractal analysis. We demonstrated that a growing bronchial tumor induced notable variations in both the airflow and exhaled aerosol distribution. These variations became more apparent with increasing tumor severity. The exhaled aerosols exhibited distinctive pattern parameters such as spatial probability, fractal dimension, and multifractal spectrum. Results of this study show that morphometric measures of the exhaled aerosol pattern can be used to detect and monitor the pathological states of respiratory diseases in the upper airway. The proposed breath test also has the potential to locate the site of the disease, which is critical in developing a personalized, site-specific drug de-livery protocol.

  3. Non-invasive bioluminescence imaging to monitor the immunological control of a plasmablastic lymphoma-like B cell neoplasia after hematopoietic cell transplantation.

    Directory of Open Access Journals (Sweden)

    Martin Chopra

    Full Text Available To promote cancer research and to develop innovative therapies, refined pre-clinical mouse tumor models that mimic the actual disease in humans are of dire need. A number of neoplasms along the B cell lineage are commonly initiated by a translocation recombining c-myc with the immunoglobulin heavy-chain gene locus. The translocation is modeled in the C.129S1-Igha(tm1(MycJanz/J mouse which has been previously engineered to express c-myc under the control of the endogenous IgH promoter. This transgenic mouse exhibits B cell hyperplasia and develops diverse B cell tumors. We have isolated tumor cells from the spleen of a C.129S1-Igha(tm1(MycJanz/J mouse that spontaneously developed a plasmablastic lymphoma-like disease. These cells were cultured, transduced to express eGFP and firefly luciferase, and gave rise to a highly aggressive, transplantable B cell lymphoma cell line, termed IM380. This model bears several advantages over other models as it is genetically induced and mimics the translocation that is detectable in a number of human B cell lymphomas. The growth of the tumor cells, their dissemination, and response to treatment within immunocompetent hosts can be imaged non-invasively in vivo due to their expression of firefly luciferase. IM380 cells are radioresistant in vivo and mice with established tumors can be allogeneically transplanted to analyze graft-versus-tumor effects of transplanted T cells. Allogeneic hematopoietic stem cell transplantation of tumor-bearing mice results in prolonged survival. These traits make the IM380 model very valuable for the study of B cell lymphoma pathophysiology and for the development of innovative cancer therapies.

  4. 3D "spectracoustic" system: a modular, tomographic, spectroscopic mapping imaging, non-invasive, diagnostic system for detection of small starting developing tumors like melanoma

    Science.gov (United States)

    Karagiannis, Georgios

    2017-03-01

    This work led to a new method named 3D spectracoustic tomographic mapping imaging. The current and the future work is related to the fabrication of a combined acoustic microscopy transducer and infrared illumination probe permitting the simultaneous acquisition of the spectroscopic and the tomographic information. This probe provides with the capability of high fidelity and precision registered information from the combined modalities named spectracoustic information.

  5. The clinical utility of FibroScan® as a noninvasive diagnostic test for liver disease

    Directory of Open Access Journals (Sweden)

    Wilder J

    2014-05-01

    Full Text Available Julius Wilder,1,2 Keyur Patel1,21Division of Gastroenterology, Duke University School of Medicine, 2Duke Clinical Research Institute, Durham, NC, USAAbstract: An important aspect of managing chronic liver disease is assessing for evidence of fibrosis. Historically, this has been accomplished using liver biopsy, which is an invasive procedure associated with risk for complications and significant sampling and observer error, limiting the accuracy for determination of fibrosis stage. Hence, several serum biomarkers and imaging methods for noninvasive assessment of liver fibrosis have been developed. In this article, we review the current literature on an important noninvasive imaging modality to measure tissue elastography (FibroScan®. This ultrasound-based technique is now increasingly available in many countries and has been shown to be a reliable and safe noninvasive means of assessing disease severity in chronic liver disease of varying etiology.Keywords: elastography, ultrasound, fibrosis, cirrhosis

  6. Influence of total beam current on HRTEM image resolution in differentially pumped ETEM with nitrogen gas.

    Science.gov (United States)

    Bright, A N; Yoshida, K; Tanaka, N

    2013-01-01

    Environmental transmission electron microscopy (ETEM) enables the study of catalytic and other reaction processes as they occur with Angstrom-level resolution. The microscope used is a dedicated ETEM (Titan ETEM, FEI Company) with a differential pumping vacuum system and apertures, allowing aberration corrected high-resolution transmission electron microscopy (HRTEM) imaging to be performed with gas pressures up to 20 mbar in the sample area and with significant advantages over membrane-type E-cell holders. The effect on image resolution of varying the nitrogen gas pressure, electron beam current density and total beam current were measured using information limit (Young's fringes) on a standard cross grating sample and from silicon crystal lattice imaging. As expected, increasing gas pressure causes a decrease in HRTEM image resolution. However, the total electron beam current also causes big changes in the image resolution (lower beam current giving better resolution), whereas varying the beam current density has almost no effect on resolution, a result that has not been reported previously. This behavior is seen even with zero-loss filtered imaging, which we believe shows that the drop in resolution is caused by elastic scattering at gas ions created by the incident electron beam. Suitable conditions for acquiring high resolution images in a gas environment are discussed. Lattice images at nitrogen pressures up to 16 mbar are shown, with 0.12 nm information transfer at 4 mbar.

  7. The role of magnetic resonance imaging in the evaluation of thalassemic syndromes: current practice and future perspectives

    Directory of Open Access Journals (Sweden)

    Sophie Mavrogeni

    2014-09-01

    Full Text Available Iron can be deposited in all internal organs, leading to different types of functional abnormalities. However, myocardial iron overload that contributes to heart failure remains one of the main causes of death in thalassemia major. Using magnetic resonance imaging, tissue iron is detected indirectly by the effects on relaxation times of ferritin and hemosiderin iron interacting with hydrogen nuclei. The presence of iron in the human body results in marked alterations of tissue relaxation times. Currently, cardiovascular magnetic resonance using T2* is routinely used in many countries to identify patients with myocardial iron loading and guide chelation therapy, specifically tailored to the heart. Myocardial T2* is the only clinically validated non-invasive measure of myocardial iron loading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. Finally, the substantial amelioration of patients’ survival, allows the detection of other organs’ abnormalities due to iron overload, apart from the heart, missed in the past. Recent studies revealed that iron deposition has a different pattern in various parenchymal organs, which is independent from serum ferritin and follows an individual way after chelation treatment application. This new upcoming reality orders a closer monitoring of all organs of the body in order to detect preclinical lesions and early apply adequate treatment.

  8. Non-invasive imaging to monitor lupus nephritis and neuropsychiatric systemic lupus erythematosus [v1; ref status: indexed, http://f1000r.es/5gh

    Directory of Open Access Journals (Sweden)

    Joshua Thurman

    2015-06-01

    Full Text Available Systemic lupus erythematosus (SLE is an autoimmune disease that can affect multiple different organs, including the kidneys and central nervous system (CNS. Conventional radiological examinations in SLE patients include volumetric/ anatomical computed tomography (CT, magnetic resonance imaging (MRI and ultrasound (US. The utility of these modalities is limited, however, due to the complexity of the disease. Furthermore, CT and MRI contrast agents are contraindicated in patients with renal impairment. Various radiologic methods are currently being developed to improve disease characterization in patients with SLE beyond simple anatomical endpoints. Physiological non-contrast MRI protocols have been developed to assess tissue oxygenation, glomerular filtration, renal perfusion, interstitial diffusion, and inflammation-driven fibrosis in lupus nephritis (LN patients. For neurological symptoms, vessel size imaging (VSI, an MRI approach utilizing T2-relaxing iron oxide nanoparticles has shown promise as a diagnostic tool. Molecular imaging probes (mostly for MRI and nuclear medicine imaging have also been developed for diagnosing SLE with high sensitivity, and for monitoring disease activity. This paper reviews the challenges in evaluating disease activity in patients with LN and neuropsychiatric systemic lupus erythematosus (NPSLE. We describe novel MRI and positron-emission tomography (PET molecular imaging protocols using targeted iron oxide nanoparticles and radioactive ligands, respectively, for detection of SLE-associated inflammation.

  9. Current imaging of nasal sinuses; Moderne Bildgebung der Nasennebenhoehlen

    Energy Technology Data Exchange (ETDEWEB)

    Reith, W. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie der Kliniken fuer Radiologie, Homburg (Germany)

    2005-09-01

    Depending on the problems, CT or MRI should be used in the differential diagnosis of conditions affecting the nasal sinuses. In particular, when chronic sinusitis is present, computed tomography should be performed before surgery to ascertain the condition of the bones. In most cases spiral CT with a decidedly lowered tube voltage and power (MAS product) is now used for this purpose. This means that the patient is exposed to about 70% less radiation than in other CT investigations. To avoid artefacts attributable to dental fillings, whenever possible the spiral should be tilted in such a way that the dental artefacts are not within the mass imaged. When an isotropic voxel is selected secondary reformatting is possible with no loss of quality. Diagnostic MRI should include both T1- and T2-weighted sequences before and after the administration of contrast agent. For the differential diagnosis of a space-occupying tumour coronal cuts about 2 mm apart are advised, whether the spiral or the conventional technique is used. A T2-weighted and fat-suppressed sequence or a STIR (short tau inversion recovery) sequence can also be helpful in the recognition and visualization of lymph nodes. If orbital involvement seems possible it is advisable to use a T1-weighted and fat-suppressed sequence in the coronal plane in addition to check this. (orig.) [German] Bei der differenzialdiagnostischen Evaluierung der Nasennebenhoehlen sollte je nach Fragestellung neben der klinischen Evaluierung die Computertomographie (CT) oder Magnetresonanztomographie eingesetzt werden. Dabei sollte zur Abklaerung einer chronischen Sinusitis praeoperativ zur Erhebung der knoechernen Situation auf die Computertomographie zurueckgegriffen werden. Heutzutage wird man hier zumeist eine Spiral-CT mit deutlich reduzierte Roehrenspannung und Strom (MAS-Produkt) zurueckgreifen. So koennen bis zu 70% Strahlung gespart werden. Um Artefakte durch Zahnfuellungen zu vermeiden sollte die Spirale, wenn moeglich, so

  10. Relativistic Quantum Noninvasive Measurements

    CERN Document Server

    Bednorz, Adam

    2014-01-01

    Quantum weak, noninvasive measurements are defined in the framework of relativity. Invariance with respect to reference frame transformations of the results in different models is discussed. Surprisingly, the bare results of noninvasive measurements are invariant for certain class of models, but not the detection error. Consequently, any stationary quantum realism based on noninvasive measurements will break, at least spontaneously, relativistic invariance and correspondence principle at zero temperature.

  11. Multimodal backside imaging of a microcontroller using confocal laser scanning and optical-beam-induced current imaging

    Science.gov (United States)

    Finkeldey, Markus; Göring, Lena; Schellenberg, Falk; Brenner, Carsten; Gerhardt, Nils C.; Hofmann, Martin

    2017-02-01

    Microscopy imaging with a single technology is usually restricted to a single contrast mechanism. Multimodal imaging is a promising technique to improve the structural information that could be obtained about a device under test (DUT). Due to the different contrast mechanisms of laser scanning microscopy (LSM), confocal laser scanning microscopy (CLSM) and optical beam induced current microscopy (OBICM), a combination could improve the detection of structures in integrated circuits (ICs) and helps to reveal their layout. While OBIC imaging is sensitive to the changes between differently doped areas and to semiconductor-metal transitions, CLSM imaging is mostly sensitive to changes in absorption and reflection. In this work we present the implementation of OBIC imaging into a CLSM. We show first results using industry standard Atmel microcontrollers (MCUs) with a feature size of about 250nm as DUTs. Analyzing these types of microcontrollers helps to improve in the field of side-channel attacks to find hardware Trojans, possible spots for laser fault attacks and for reverse engineering. For the experimental results the DUT is placed on a custom circuit board that allows us to measure the current while imaging it in our in-house built stage scanning microscope using a near infrared (NIR) laser diode as light source. The DUT is thinned and polished, allowing backside imaging through the Si-substrate. We demonstrate the possibilities using this optical setup by evaluating OBIC, LSM and CLSM images above and below the threshold of the laser source.

  12. Noninvasive near-infrared live imaging of human adult mesenchymal stem cells transplanted in a rodent model of Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Bossolasco P

    2012-01-01

    Full Text Available P Bossolasco1,*, L Cova2,*, G Levandis3, V Diana2, S Cerri3, G Lambertenghi Deliliers1, E Polli1, V Silani2,4, F Blandini3, MT Armentero31Fondazione Matarelli, Dipartimento di Farmacologia, Chemioterapia e Tossicologia Medica, Università degli Studi di Milano, Milan, 2Department of Neurology and Laboratory of Neuroscience-IRCCS Istituto Auxologico Italiano, Cusano Milanino, 3Laboratory of Functional Neurochemistry, Interdepartmental Research Centre for Parkinson’s Disease, IRCCS National Institute of Neurology “C Mondino”, Pavia, 4Department of Neurology and Laboratory of Neuroscience, Centro “Dino Ferrari” Università degli Studi di Milano-IRCCS Istituto Auxologico Italiano, Milan, Italy *These authors contributed equally to this workBackground: We have previously shown that human mesenchymal stem cells (hMSCs can reduce toxin-induced neurodegeneration in a well characterized rodent model of Parkinson’s disease. However, the precise mechanisms, optimal cell concentration required for neuroprotection, and detailed cell tracking need to be defined. We exploited a near-infrared imaging platform to perform noninvasive tracing following transplantation of tagged hMSCs in live parkinsonian rats.Methods: hMSCs were labeled both with a membrane intercalating dye, emitting in the near-infrared 815 nm spectrum, and the nuclear counterstain, Hoechst 33258. Effects of near-infrared dye on cell metabolism and proliferation were extensively evaluated in vitro. Tagged hMSCs were then administered to parkinsonian rats bearing a 6-hydroxydopamine-induced lesion of the nigrostriatal pathway, via two alternative routes, ie, intrastriatal or intranasal, and the cells were tracked in vivo and ex vivo using near-infrared technology.Results: In vitro, NIR815 staining was stable in long-term hMSC cultures and did not interfere with cell metabolism or proliferation. A significant near-infrared signal was detectable in vivo, confined around the injection

  13. Analysis of reliability metrics and quality enhancement measures in current density imaging.

    Science.gov (United States)

    Foomany, F H; Beheshti, M; Magtibay, K; Masse, S; Foltz, W; Sevaptsidis, E; Lai, P; Jaffray, D A; Krishnan, S; Nanthakumar, K; Umapathy, K

    2013-01-01

    Low frequency current density imaging (LFCDI) is a magnetic resonance imaging (MRI) technique which enables calculation of current pathways within the medium of study. The induced current produces a magnetic flux which presents itself in phase images obtained through MRI scanning. A class of LFCDI challenges arises from the subject rotation requirement, which calls for reliability analysis metrics and specific image registration techniques. In this study these challenges are formulated and in light of proposed discussions, the reliability analysis of calculation of current pathways in a designed phantom and a pig heart is presented. The current passed is measured with less than 5% error for phantom, using CDI method. It is shown that Gauss's law for magnetism can be treated as reliability metric in matching the images in two orientations. For the phantom and pig heart the usefulness of image registration for mitigation of rotation errors is demonstrated. The reliability metric provides a good representation of the degree of correspondence between images in two orientations for phantom and pig heart. In our CDI experiments this metric produced values of 95% and 26%, for phantom, and 88% and 75% for pig heart, for mismatch rotations of 0 and 20 degrees respectively.

  14. SU-E-I-79: Correction of Dark Current and Image Lag in Multi-Source Carbon Nanotube Imaging Systems.

    Science.gov (United States)

    Frederick, C; Lalush, D; Chang, S

    2012-06-01

    To correct for dark current and detector image lag in multi-source carbon nanotube (CNT) based imaging systems. CNTs can be used as a novel electron source for X-ray generation. Here a small (∼2 kV) gate voltage induces a large electric field at the CNT tip that causes field emission as opposed to thermionic emission. This enables faster switching times and allows miniaturization which aids in the development of stationary multi-source systems. These systems may encounter two key problems: dark current in non-active sources and detector lag. In damaged and perhaps end-of-life devices, sources may develop significant electron output without gate voltage, interfering with images from non-active sources. Although the output is small, it is constant, and continuous integration of detectors compared with small X-ray exposure time magnifies its contribution to the signal. A method based on binary multiplexing is developed to mitigate the dark current contributions possibly extending device lifetime. Having discrete sources, these multi-source systems have coarser angular sampling than rotating systems. This coarser sampling means that the detector signal changes more in adjacent projections than rotating systems exacerbating the effect of detector lag. Since flat panel detectors have a capacitive behavior, readout only removes some charge from pixels. As a result, a device dependent amount (6.6% in our device) of the signal from the current image contributes to the subsequent image. A fast, stable inverse filter separating detector lag has been developed. Projection data were simulated based on parameters measured from a multi-source CNT system. Incorporating dark current and image lag phenomena into reconstruction improves contrast to noise ratio. These correction methods can be easily implemented on clinical multi-source systems to improve image quality and extend the device's usable lifetime. Supported in part by Siemens Medical. © 2012 American Association of

  15. Non-invasive imaging of cysteine cathepsin activity in solid tumors using a 64Cu-labeled activity-based probe.

    Directory of Open Access Journals (Sweden)

    Gang Ren

    Full Text Available The papain family of cysteine cathepsins are actively involved in multiple stages of tumorigenesis. Because elevated cathepsin activity can be found in many types of human cancers, they are promising biomarkers that can be used to target radiological contrast agents for tumor detection. However, currently there are no radiological imaging agents available for these important molecular targets. We report here the development of positron emission tomography (PET radionuclide-labeled probes that target the cysteine cathepsins by formation of an enzyme activity-dependent bond with the active site cysteine. These probes contain an acyloxymethyl ketone (AOMK functional group that irreversibly labels the active site cysteine of papain family proteases attached to a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA tag for labeling with (64Cu for PET imaging studies. We performed biodistribution and microPET imaging studies in nude mice bearing subcutaneous tumors expressing various levels of cysteine cathepsin activity and found that the extent of probe uptake by tumors correlated with overall protease activity as measured by biochemical methods. Furthermore, probe signals could be reduced by pre-treatment with a general cathepsin inhibitor. We also found that inclusion of a Cy5 tag on the probe increased tumor uptake relative to probes lacking this fluorogenic dye. Overall, these results demonstrate that small molecule activity-based probes carrying radio-tracers can be used to image protease activity in living subjects.

  16. Conductivity and current density image reconstruction using harmonic Bz algorithm in magnetic resonance electrical impedance tomography.

    Science.gov (United States)

    Oh, Suk Hoon; Lee, Byung Il; Woo, Eung Je; Lee, Soo Yeol; Cho, Min Hyoung; Kwon, Ohin; Seo, Jin Keun

    2003-10-07

    Magnetic resonance electrical impedance tomography (MREIT) is to provide cross-sectional images of the conductivity distribution sigma of a subject. While injecting current into the subject, we measure one component Bz of the induced magnetic flux density B = (Bx, By, Bz) using an MRI scanner. Based on the relation between (inverted delta)2 Bz and inverted delta sigma, the harmonic Bz algorithm reconstructs an image of sigma using the measured Bz data from multiple imaging slices. After we obtain sigma, we can reconstruct images of current density distributions for any given current injection method. Following the description of the harmonic Bz algorithm, this paper presents reconstructed conductivity and current density images from computer simulations and phantom experiments using four recessed electrodes injecting six different currents of 26 mA. For experimental results, we used a three-dimensional saline phantom with two polyacrylamide objects inside. We used our 0.3 T (tesla) experimental MRI scanner to measure the induced Bz. Using the harmonic Bz algorithm, we could reconstruct conductivity and current density images with 82 x 82 pixels. The pixel size was 0.6 x 0.6 mm2. The relative L2 errors of the reconstructed images were between 13.8 and 21.5% when the signal-to-noise ratio (SNR) of the corresponding MR magnitude images was about 30. The results suggest that in vitro and in vivo experimental studies with animal subjects are feasible. Further studies are requested to reduce the amount of injection current down to less than 1 mA for human subjects.

  17. A Comparative Study of Noninvasive Hypoxia Imaging with 18F-Fluoroerythronitroimidazole and 18F-Fluoromisonidazole PET/CT in Patients with Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Yuchun Wei

    Full Text Available This is a clinical study to compare noninvasive hypoxia imaging using 18F-fluoroerythronitroimidazole (18F-FETNIM and 18F-fluoromisonidazole (18F-FMISO positron emission tomography/computed tomography (PET/CT in patients with inoperable stages III-IV lung cancer.A total of forty-two patients with inoperable stages III-IV lung cancer underwent 18F-FETNIM PET/CT (n = 18 and 18F-FMISO PET/CT (n = 24 before chemo/radiation therapy. The standard uptake values (SUVs of malignant and normal tissues depict 18F-FETNIM PET/CT and 18F-FMISO PET/CT uptake. Tumor-to-blood ratios (T/B were used to quantify hypoxia.All patients with lung cancer underwent 18F-FETNIM PET/CT and 18F-FMISO PET/CT successfully. Compared to 18F-FMISO, 18F-FETNIM showed similar uptake in muscle, thyroid, spleen, pancreas, heart, lung and different uptake in blood, liver, and kidney. Significantly higher SUV and T/B ratio with 18F-FMISO (2.56±0.77, 1.98±0.54, as compared to 18F-FETNIM (2.12±0.56, 1.42±0.33 were seen in tumor, P = 0.022, 5cm groups in 18F-FMISO PET/CT, P = 0.015 (or P = 0.029, whereas no difference was detected in 18F-FMISO PET/CT, P = 0.446 (or P = 0.707. Both 18F-FETNIM and 18F-FMISO showed significantly higher SUVs (or T/B ratios in stage IV than stage III, P = 0.021, 0.013 (or P = 0.032, 0.02.18F-FMISO showed significantly higher uptake than 18F-FETNIM in tumor/non-tumor ratio and might be a better hypoxia tracer in lung cancer.

  18. Magnetic resonance electrical impedance tomography (MREIT): conductivity and current density imaging

    Science.gov (United States)

    Seo, Jin Keun; Kwon, Ohin; Woo, Eung Je

    2005-01-01

    This paper reviews the latest impedance imaging technique called Magnetic Resonance Electrical Impedance Tomography (MREIT) providing information on electrical conductivity and current density distributions inside an electrically conducting domain such as the human body. The motivation for this research is explained by discussing conductivity changes related with physiological and pathological events, electromagnetic source imaging and electromagnetic stimulations. We briefly summarize the related technique of Electrical Impedance Tomography (EIT) that deals with cross-sectional image reconstructions of conductivity distributions from boundary measurements of current-voltage data. Noting that EIT suffers from the ill-posed nature of the corresponding inverse problem, we introduce MREIT as a new conductivity imaging modality providing images with better spatial resolution and accuracy. MREIT utilizes internal information on the induced magnetic field in addition to the boundary current-voltage measurements to produce three-dimensional images of conductivity and current density distributions. Mathematical theory, algorithms, and experimental methods of current MREIT research are described. With numerous potential applications in mind, future research directions in MREIT are proposed.

  19. Body image disturbance in children and adolescents with eating disorders. Current evidence and future directions.

    Science.gov (United States)

    Legenbauer, Tanja; Thiemann, Pia; Vocks, Silja

    2014-01-01

    Body image is multifaceted and incorporates perceptual, affective, and cognitive components as well as behavioral features. Only few studies have examined the character of body-image disturbance in children/adolescents with eating disorders. It is unknown whether body-image disturbances in children/adolescent with eating disturbances are comparable to those of adult patients with eating disorders. Body-image disturbance might differ quantitatively and qualitatively according to the cognitive developmental status and the age of the individual. This paper provides an overview of the current evidence for body-image disturbance in children/adolescents with eating disorders, and how they compare with those adults with eating disorders. Current evidence indicates that older adolescent patients show similar deficits as adult patients with eating disorders, in particular for the attitudinal body-image component. However, evidence for a perceptual body-image disturbance in adolescent patients, in particular anorexia nervosa, is not conclusive. Reliable statements for childhood can hardly be made because clinical studies are not available. Investigations of body-image disturbance in children have focused on the predictive value for eating disorders. Limitations of the current evidence are discussed, and future directions for research and therapy are indicated.

  20. Imaging evaluation of complications of hip arthroplasty: review of current concepts and imaging findings.

    Science.gov (United States)

    Awan, Omer; Chen, Lina; Resnik, Charles S

    2013-11-01

    Total hip arthroplasty has evolved along with improvements in component materials and design. The radiologist must accurately diagnose associated complications with imaging methods and stay informed about newer complications associated with innovations in surgical technique, prosthetic design, and novel materials. This pictorial essay presents clinical and imaging correlation of modern hip arthroplasty complications, with an emphasis on the most common complications of instability, aseptic loosening, and infection as well as those complications associated with contemporary metal-on-metal arthroplasty.

  1. Role of imaging in testicular cancer: current and future practice.

    Science.gov (United States)

    Barrisford, Glen W; Kreydin, Evgeniy I; Preston, Mark A; Rodriguez, Dayron; Harisighani, Mukesh G; Feldman, Adam S

    2015-09-01

    The article provides a summary of the epidemiologic and clinical aspects of testicular malignancy. Current standard imaging and novel techniques are reviewed. Present data and clinical treatment trends have favored surveillance protocols over adjuvant radiation or chemotherapy for low-stage testicular malignancy. This has resulted in increasing numbers of imaging studies and the potential for increased long-term exposure risks. Understanding imaging associated risks as well as strategies to minimize these risks is of increasing importance. The development, validation and incorporation of alternative lower risk highly efficacious and cost-effective imaging techniques is essential.

  2. Evaluation of a 99mTc-labeled AnnexinA5 variant for non-invasive SPECT imaging of cell death in liver, spleen and prostate.

    NARCIS (Netherlands)

    Greupink, A.H.; Sio, C.F.; Ederveen, A.; Orsel, J.

    2009-01-01

    PURPOSE: We investigate radio-labeling and pharmacokinetics of a new AnnexinA5 variant (HYNIC-cys-AnxA5) and then assess its utility for the non-invasive detection of cell death in liver, spleen and prostate. METHODS: AnnexinA5 binds to phosphatidylserine expressed on the surface of apoptotic and ne

  3. In-vivo Imaging of Magnetic Fields Induced by Transcranial Direct Current Stimulation (tDCS) in Human Brain using MRI

    Science.gov (United States)

    Jog, Mayank V.; Smith, Robert X.; Jann, Kay; Dunn, Walter; Lafon, Belen; Truong, Dennis; Wu, Allan; Parra, Lucas; Bikson, Marom; Wang, Danny J. J.

    2016-10-01

    Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique that applies mA currents at the scalp to modulate cortical excitability. Here, we present a novel magnetic resonance imaging (MRI) technique, which detects magnetic fields induced by tDCS currents. This technique is based on Ampere’s law and exploits the linear relationship between direct current and induced magnetic fields