WorldWideScience

Sample records for noninvasive functional imaging

  1. 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. © NEPjOPH.

  2. 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.

  3. In vivo, noninvasive functional measurements of bone sarcoma using diffuse optical spectroscopic imaging

    Science.gov (United States)

    Peterson, Hannah M.; Hoang, Bang H.; Geller, David; Yang, Rui; Gorlick, Richard; Berger, Jeremy; Tingling, Janet; Roth, Michael; Gill, Jonathon; Roblyer, Darren

    2017-12-01

    Diffuse optical spectroscopic imaging (DOSI) is an emerging near-infrared imaging technique that noninvasively measures quantitative functional information in thick tissue. This study aimed to assess the feasibility of using DOSI to measure optical contrast from bone sarcomas. These tumors are rare and pose technical and practical challenges for DOSI measurements due to the varied anatomic locations and tissue depths of presentation. Six subjects were enrolled in the study. One subject was unable to be measured due to tissue contact sensitivity. For the five remaining subjects, the signal-to-noise ratio, imaging depth, optical properties, and quantitative tissue concentrations of oxyhemoglobin, deoxyhemoglobin, water, and lipids from tumor and contralateral normal tissues were assessed. Statistical differences between tumor and contralateral normal tissue were found in chromophore concentrations and optical properties for four subjects. Low signal-to-noise was encountered during several subject's measurements, suggesting increased detector sensitivity will help to optimize DOSI for this patient population going forward. This study demonstrates that DOSI is capable of measuring optical properties and obtaining functional information in bone sarcomas. In the future, DOSI may provide a means to stratify treatment groups and monitor chemotherapy response for this disease.

  4. Noninvasive imaging of transplanted living functional cells transfected with a reporter estrogen receptor gene

    International Nuclear Information System (INIS)

    Takamatsu, Shinji; Furukawa, Takako; Mori, Tetsuya; Yonekura, Yoshiharu; Fujibayashi, Yasuhisa

    2005-01-01

    The transplantation of functional cells such as dopaminergic cells into damaged tissue is now clinically ongoing, but at present the population of surviving cells at the transplantation site mostly cannot be noninvasively examined. To visualize surviving transplanted functional cells using a noninvasive method, we chose the estrogen receptor ligand binding domain (ERL) as a reporter molecule and 16α-[ 18 F]-fluoro-17β-estradiol (FES) for its ligand. We used a mouse embryonic stem (ES) cell line for recipient cells as a model. To obtain ES cells that constitutively or inducibly express ERL, we transfected two types of expression vectors into EB5 parental ES cell line using the lipofection method and obtained about 30 clones for each of the two types of transfectants. Then, to examine the expression level of ERL, we performed Western blotting analysis. Ligand uptake experiments were carried out using [ 3 H]-estradiol with or without excessive unlabeled estradiol for control cells and ERL transfectants. Each selected clone was also used for in vivo positron emission tomography (PET) imaging studies involving FES in nude mice transplanted with control cells and ERL transfectants. In some of the clones transfected with the inducible-type ERL gene, protein was expressed much higher than in the controls. However, constitutive-type ERL gene-transfected ES cells showed no protein production in spite of their gene expression activity being considerably high. All clones also expressed equal levels of the Oct-3/4 gene, a marker of pluripotency, in comparison with the parental cells. Also, the specific uptake of [ 3 H]-estradiol was over 30 times higher in inducer-treated ERL-expressing ES cells compared to untreated control cells. Finally, by performing dynamic PET imaging, we successfully visualized ERL-expressing teratomas using FES

  5. Non-invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognitive Functions

    Science.gov (United States)

    2017-05-14

    neuropsychological tests: cognitive performance, perceptual reasoning, working memory , processing speed and perceived stress scale were performed. Brain...AFRL-AFOSR-JP-TR-2017-0052 Non-invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognative Functions...invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognative Functions 5a.  CONTRACT NUMBER 5b.  GRANT

  6. Functional Coexpression of HSV-1 Thymidine Kinase and Green Fluorescent Protein: Implications for Noninvasive Imaging of Transgene Expression

    Directory of Open Access Journals (Sweden)

    Andreas Jacobs

    1999-06-01

    Full Text Available Current gene therapy technology is limited by the paucity of methodology for determining the location and magnitude of therapeutic transgene expression in vivo. We describe and validate a paradigm for monitoring therapeutic transgene expression by noninvasive imaging of the herpes simplex virus type 1 thymidine kinase (HSV-1-tk marker gene expression. To test proportional coexpression of therapeutic and marker genes, a model fusion gene comprising green fluorescent protein (gfp and HSV-1-tk genes was generated (tkgfp gene and assessed for the functional coexpression of the gene product, TKGFP fusion protein, in rat 9L gliosarcoma, RG2 glioma, and W256 carcinoma cells. Analysis of the TKGFP protein demonstrated that it can serve as a therapeutic gene by rendering tkgfp transduced cells sensitive to ganciclovir or as a screening marker useful for identifying transduced cells by fluorescence microscopy or fluorescence-activated cell sorting (FACS. TK and GFP activities in the TKGFP fusion protein were similar to corresponding wild-type proteins and accumulation of the HSV-1-tk-specific radiolabeled substrate, 2′-fluoro-2′-deoxy-1β-D-arabino-furanosyl-5-iodo-uracil (FIAU, in stability transduced clones correlated with gfp-fluorescence intensity over a wide range of expression levels. The tkgfp fusion gene itself may be useful in developing novel cancer gene therapy approaches. Valuable information about the efficiency of gene transfer and expression could be obtained by non-invasive imaging of tkgfp expression with FIAU and clinical imaging devices (gamma camera, positron-emission tomography [PET], single photon emission computed tomography [SPECT], and/or direct visualization of gfp expression in situ by fluorescence microscopy or endoscopy.

  7. Feasibility study of the non-invasive estimation of the β+ arterial input function for human PET imaging

    International Nuclear Information System (INIS)

    Hubert, X.

    2009-12-01

    This work deals with the estimation of the concentration of molecules in arterial blood which are labelled with positron-emitting radioelements. This concentration is called 'β + arterial input function'. This concentration has to be estimated for a large number of pharmacokinetic analyses. Nowadays it is measured through series of arterial sampling, which is an accurate method but requiring a stringent protocol. Complications might occur during arterial blood sampling because this method is invasive (hematomas, nosocomial infections). The objective of this work is to overcome this risk through a non-invasive estimation of β + input function with an external detector and a collimator. This allows the reconstruction of blood vessels and thus the discrimination of arterial signal from signals in other tissues. Collimators in medical imaging are not adapted to estimate β + input function because their sensitivity is very low. During this work, they are replaced by coded-aperture collimators, originally developed for astronomy. New methods where coded apertures are used with statistical reconstruction algorithms are presented. Techniques for analytical ray-tracing and for the acceleration of reconstructions are proposed. A new method which decomposes reconstructions on temporal sets and on spatial sets is also developed to efficiently estimate arterial input function from series of temporal acquisitions. This work demonstrates that the trade-off between sensitivity and spatial resolution in PET can be improved thanks to coded aperture collimators and statistical reconstruction algorithm; it also provides new tools to implement such improvements. (author)

  8. 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.

  9. Functional Coexpression of HSV-1 Thymidine Kinase and Green Fluorescent Protein: Implications for Noninvasive Imaging of Transgene Expression

    OpenAIRE

    Jacobs, Andreas; Dubrovin, Michael; Hewett, Jeff; Sena-Esteves, Miguel; Tan, Cui-Wen; Slack, Mark; Sadelain, Michele; Breakefield, Xandra O; Tjuvajev, Juri G

    1999-01-01

    Current gene therapy technology is limited by the paucity of methodology for determining the location and magnitude of therapeutic transgene expression in vivo. We describe and validate a paradigm for monitoring therapeutic transgene expression by noninvasive imaging of the herpes simplex virus type 1 thymidine kinase (HSV-1-tk) marker gene expression. To test proportional coexpression of therapeutic and marker genes, a model fusion gene comprising green fluorescent protein (gfp) and HSV-1-tk...

  10. 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.

  11. Non-invasive estimation of hepatic blood perfusion from H215O PET images using tissue-derived arterial and portal input functions

    International Nuclear Information System (INIS)

    Kudomi, N.; Slimani, L.; Jaervisalo, M.J.; Lautamaeki, R.; Naum, G.A.; Knuuti, J.; Kiss, J.; Savunen, T.; Iida, H.; Nuutila, P.; Iozzo, P.

    2008-01-01

    The liver is perfused through the portal vein and the hepatic artery. When its perfusion is assessed using positron emission tomography (PET) and 15 O-labeled water (H 2 15 O), calculations require a dual blood input function (DIF), i.e., arterial and portal blood activity curves. The former can be generally obtained invasively, but blood withdrawal from the portal vein is not feasible in humans. The aim of the present study was to develop a new technique to estimate quantitative liver perfusion from H 2 15 O PET images with a completely non-invasive approach. We studied normal pigs (n=14) in which arterial and portal blood tracer concentrations and Doppler ultrasonography flow rates were determined invasively to serve as reference measurements. Our technique consisted of using model DIF to create tissue model function and the latter method to simultaneously fit multiple liver time-activity curves from images. The parameters obtained reproduced the DIF. Simulation studies were performed to examine the magnitude of potential biases in the flow values and to optimize the extraction of multiple tissue curves from the image. The simulation showed that the error associated with assumed parameters was 2 15 O PET imaging. This suggests the possibility to enable completely non-invasive technique to assess liver perfusion in patho-physiological studies. (orig.)

  12. Non-invasive estimation of hepatic blood perfusion from H{sub 2} {sup 15}O PET images using tissue-derived arterial and portal input functions

    Energy Technology Data Exchange (ETDEWEB)

    Kudomi, N.; Slimani, L.; Jaervisalo, M.J.; Lautamaeki, R.; Naum, G.A.; Knuuti, J. [University of Turku, Turku PET Centre (Finland); Kiss, J.; Savunen, T. [University of Turku, Department on Surgery, Turku (Finland); Iida, H. [National Cardiovascular Center-Research Institute, Department of Investigative Radiology, Advanced Medical-Engineering Center, Suita, Osaka (Japan); Nuutila, P. [University of Turku, Turku PET Centre (Finland); University of Turku, Department of Medicine, Turku (Finland); Iozzo, P. [University of Turku, Turku PET Centre (Finland); National Research Council, Institute of Clinical Physiology, Pisa (Italy)

    2008-10-15

    The liver is perfused through the portal vein and the hepatic artery. When its perfusion is assessed using positron emission tomography (PET) and {sup 15}O-labeled water (H{sub 2}{sup 15}O), calculations require a dual blood input function (DIF), i.e., arterial and portal blood activity curves. The former can be generally obtained invasively, but blood withdrawal from the portal vein is not feasible in humans. The aim of the present study was to develop a new technique to estimate quantitative liver perfusion from H{sub 2}{sup 15}O PET images with a completely non-invasive approach. We studied normal pigs (n=14) in which arterial and portal blood tracer concentrations and Doppler ultrasonography flow rates were determined invasively to serve as reference measurements. Our technique consisted of using model DIF to create tissue model function and the latter method to simultaneously fit multiple liver time-activity curves from images. The parameters obtained reproduced the DIF. Simulation studies were performed to examine the magnitude of potential biases in the flow values and to optimize the extraction of multiple tissue curves from the image. The simulation showed that the error associated with assumed parameters was <10%, and the optimal number of tissue curves was between 10 and 20. The estimated DIFs were well reproduced against the measured ones. In addition, the calculated liver perfusion values were not different between the methods and showed a tight correlation (r=0.90). In conclusion, our results demonstrate that DIF can be estimated directly from tissue curves obtained through H{sub 2}{sup 15}O PET imaging. This suggests the possibility to enable completely non-invasive technique to assess liver perfusion in patho-physiological studies. (orig.)

  13. Non-invasive estimation of hepatic glucose uptake from [{sup 18}F]FDG PET images using tissue-derived input functions

    Energy Technology Data Exchange (ETDEWEB)

    Kudomi, N.; Jaervisalo, M.J.; Borra, R.; Viljanen, A.; Viljanen, T.; Knuuti, J. [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Kiss, J.; Savunen, T. [University of Turku, Department of Surgery, Turku (Finland); Iida, H. [National Cardiovascular Center-Research Institute, Department of Investigative Radiology, Advanced Medical Engineering Center, Suita, Osaka (Japan); Nuutila, P. [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); University of Turku, Department of Medicine, Turku (Finland); Iozzo, P. [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); National Research Council, Institute of Clinical Physiology, Pisa (Italy)

    2009-12-15

    The liver is perfused through the portal vein and hepatic artery. Quantification of hepatic glucose uptake (HGU) using PET requires the use of an input function for both the hepatic artery and portal vein. The former can be generally obtained invasively, but blood withdrawal from the portal vein is not practical in humans. The aim of this study was to develop and validate a new technique to obtain quantitative HGU by estimating the input function from PET images. Normal pigs (n = 12) were studied with [{sup 18}F]FDG PET, in which arterial and portal blood time-activity curves (TAC) were determined invasively to serve as reference measurements. The present technique consisted of two characteristics, i.e. using a model input function and simultaneously fitting multiple liver tissue TACs from images by minimizing the residual sum of square between the tissue TACs and fitted curves. The input function was obtained from the parameters determined from the fitting. The HGU values were computed by the estimated and measured input functions and compared between the methods. The estimated input functions were well reproduced. The HGU values, ranging from 0.005 to 0.02 ml/min per ml, were not significantly different between the two methods (r = 0.95, p < 0.001). A Bland-Altman plot demonstrated a small overestimation by the image-derived method with a bias of 0.00052 ml/min per g for HGU. The results presented demonstrate that the input function can be estimated directly from the PET image, supporting the fully non-invasive assessment of liver glucose metabolism in human studies. (orig.)

  14. 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.)

  15. 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. © 2015 by the Wound Healing Society.

  16. Critical Review of Noninvasive Optical Technologies for Wound Imaging

    OpenAIRE

    Jayachandran, Maanasa; Rodriguez, Suset; Solis, Elizabeth; Lei, Jiali; Godavarty, Anuradha

    2016-01-01

    Significance: Noninvasive imaging approaches can provide greater information about a wound than visual inspection during the wound healing and treatment process. This review article focuses on various optical imaging techniques developed to image different wound types (more specifically ulcers).

  17. 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.

  18. Techniques of noninvasive optical tomographic imaging

    Science.gov (United States)

    Rosen, Joseph; Abookasis, David; Gokhler, Mark

    2006-01-01

    Recently invented methods of optical tomographic imaging through scattering and absorbing media are presented. In one method, the three-dimensional structure of an object hidden between two biological tissues is recovered from many noisy speckle pictures obtained on the output of a multi-channeled optical imaging system. Objects are recovered from many speckled images observed by a digital camera through two stereoscopic microlens arrays. Each microlens in each array generates a speckle image of the object buried between the layers. In the computer each image is Fourier transformed jointly with an image of the speckled point-like source captured under the same conditions. A set of the squared magnitudes of the Fourier-transformed pictures is accumulated to form a single average picture. This final picture is again Fourier transformed, resulting in the three-dimensional reconstruction of the hidden object. In the other method, the effect of spatial longitudinal coherence is used for imaging through an absorbing layer with different thickness, or different index of refraction, along the layer. The technique is based on synthesis of multiple peak spatial degree of coherence. This degree of coherence enables us to scan simultaneously different sample points on different altitudes, and thus decreases the acquisition time. The same multi peak degree of coherence is also used for imaging through the absorbing layer. Our entire experiments are performed with a quasi-monochromatic light source. Therefore problems of dispersion and inhomogeneous absorption are avoided.

  19. 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.

  20. Functional brain imaging

    International Nuclear Information System (INIS)

    Frackowiak, R.S.J.

    1996-01-01

    Major advances in computing and mathematics, especially the back-projection algorithms introduced for reconstructing tomographic data obtained by non-invasive imaging, have led to new opportunities for the study of the structure, function and structure-function relationships of the human brain. Functional neuro-imaging methods fall, broadly, into two classes. Those methods that provide information about synaptic activity and those that provide information of a chemical or neurochemical nature. The former methods usually depend on some form of perfusion mapping because of the tight coupling between local glucose metabolism and blood flow in the brain at rest and at times of altered synaptic activity. The latter methods depend on identification of a chemical species of interest by using an appropriate radioligand, or by using the intrinsic magnetic properties of a compound. (author)

  1. 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...

  2. 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...

  3. An Image Registration Based Technique for Noninvasive Vascular Elastography

    OpenAIRE

    Valizadeh, Sina; Makkiabadi, Bahador; Mirbagheri, Alireza; Soozande, Mehdi; Manwar, Rayyan; Mozaffarzadeh, Moein; Nasiriavanaki, Mohammadreza

    2018-01-01

    Non-invasive vascular elastography is an emerging technique in vascular tissue imaging. During the past decades, several techniques have been suggested to estimate the tissue elasticity by measuring the displacement of the Carotid vessel wall. Cross correlation-based methods are the most prevalent approaches to measure the strain exerted in the wall vessel by the blood pressure. In the case of a low pressure, the displacement is too small to be apparent in ultrasound imaging, especially in th...

  4. 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…

  5. 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.

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

    Science.gov (United States)

    Eriksson, Sam; Nilsson, Jan; Sturesson, Christian

    2014-01-01

    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.

  7. 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.

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

    OpenAIRE

    Sturesson, Christian; Nilsson,Jan; Eriksson,Sam

    2014-01-01

    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 c...

  9. Noninvasive imaging in acute coronary disease. A clinical perspective

    International Nuclear Information System (INIS)

    Gersh, B.J.

    1991-01-01

    Numerous highly complex and sensitive noninvasive imaging techniques have enhanced the care of patients with acute myocardial infarction. Optimum use requires specific objectives to be defined in advance, including a review of the potential impact of the test on subsequent decisions. An additional issue that is subject to scrutiny in the current climate of cost containment relates to the incremental value of a specific examination. The imaging modality to be used will partially depend on other issues, including accessibility, cost, and interindividual or institutional expertise with a particular technique. Major applications in noninvasive imaging in the acute coronary syndromes include the following: (1) diagnosis, including identification of associated diseases and contraindications for acute reperfusion; (2) evaluation and management of complications; (3) determination of prognosis (both early and late); (4) estimation of myocardial viability; (5) assessment of therapeutic efficacy; (6) investigational approaches, including 99mTc-sestamibi tomographic imaging, ultrafast cine computed tomographic scanning, and nuclear magnetic resonance imaging. Previous studies in the prethrombolytic era have documented the powerful impact of radionuclide stress testing on prognosis, but this needs to be reevaluated in the light of the changing current population undergoing stress testing. Preliminary data imply that the prognostic accuracy of stress testing after thrombolytic therapy is diminished. Moreover, the role of the open infarct-related artery in traditional estimates of prognosis requires further study. Noninvasive imaging has multiple applications in the diagnosis and management of patients with acute coronary disease, but the decision to use a specific technology in a particular circumstance mandates good clinical judgment and selectivity. 82 references

  10. Noninvasive measurement of dynamic correlation functions

    CSIR Research Space (South Africa)

    Uhrich, P

    2017-08-01

    Full Text Available )spin systems and arbitrary equilibrium or nonequilibrium initial states. Different choices of the coupling operator give access to the real and imaginary parts of the dynamic correlation function. This protocol reduces disturbances due to the early...

  11. Feasibility study of the non-invasive estimation of the {beta}{sup +} arterial input function for human PET imaging; Etude de faisabilite de l'estimation non-invasive de la fonction d'entree arterielle {beta}{sup +} pour l'imagerie TEP chez l'homme

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, X.

    2009-12-15

    This work deals with the estimation of the concentration of molecules in arterial blood which are labelled with positron-emitting radioelements. This concentration is called '{beta}{sup +} arterial input function'. This concentration has to be estimated for a large number of pharmacokinetic analyses. Nowadays it is measured through series of arterial sampling, which is an accurate method but requiring a stringent protocol. Complications might occur during arterial blood sampling because this method is invasive (hematomas, nosocomial infections). The objective of this work is to overcome this risk through a non-invasive estimation of {beta}{sup +} input function with an external detector and a collimator. This allows the reconstruction of blood vessels and thus the discrimination of arterial signal from signals in other tissues. Collimators in medical imaging are not adapted to estimate {beta}{sup +} input function because their sensitivity is very low. During this work, they are replaced by coded-aperture collimators, originally developed for astronomy. New methods where coded apertures are used with statistical reconstruction algorithms are presented. Techniques for analytical ray-tracing and for the acceleration of reconstructions are proposed. A new method which decomposes reconstructions on temporal sets and on spatial sets is also developed to efficiently estimate arterial input function from series of temporal acquisitions. This work demonstrates that the trade-off between sensitivity and spatial resolution in PET can be improved thanks to coded aperture collimators and statistical reconstruction algorithm; it also provides new tools to implement such improvements. (author)

  12. Noninvasive Imaging of Colitis Using Multispectral Optoacoustic Tomography.

    Science.gov (United States)

    Bhutiani, Neal; Grizzle, William E; Galandiuk, Susan; Otali, Denis; Dryden, Gerald W; Egilmez, Nejat K; McNally, Lacey R

    2017-06-01

    Currently, several noninvasive modalities, including MRI and PET, are being investigated to identify early intestinal inflammation, longitudinally monitor disease status, or detect dysplastic changes in patients with inflammatory bowel disease. Here, we assess the applicability and utility of multispectral optoacoustic tomography (MSOT) in evaluating the presence and severity of colitis. Methods: C57B/6 mice were untreated or treated with Bacteroides fragilis and antibiotic-mediated depletion of intestinal flora to initiate colitis. Mice were imaged using MSOT to detect intestinal inflammation. Intestinal inflammation identified with MSOT was also confirmed using both colonoscopy and histology. Results: Mice with bacterial colitis demonstrated a temporally associated increase in mesenteric and colonic vascularity with an increase in mean signal intensity of oxygenated hemoglobin ( P = 0.004) by MSOT 2 d after inoculation. These findings were significantly more prominent 7 d after inoculation, with increased mean signal intensity of oxygenated hemoglobin ( P = 0.0002) and the development of punctate vascular lesions on the colonic surface, which corresponded to changes observed on colonoscopy as well as histology. Conclusion: With improvements in depth of tissue penetration, MSOT may hold potential as a sensitive, accurate, noninvasive imaging tool in the evaluation of patients with inflammatory bowel disease. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  13. 2017 multimodality appropriate use criteria for noninvasive cardiac imaging: Export consensus of the Asian society of cardiovascular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Kyong Min Sarah [Dept. of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Kim, Jeong A [Dept. of Radiology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of); Choe, Yeon Hyeon [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); and others

    2017-11-15

    In 2010, the Asian Society of Cardiovascular Imaging (ASCI) provided recommendations for cardiac CT and MRI, and this document reflects an update of the 2010 ASCI appropriate use criteria (AUC). In 2016, the ASCI formed a new working group for revision of AUC for noninvasive cardiac imaging. A major change that we made in this document is the rating of various noninvasive tests (exercise electrocardiogram, echocardiography, positron emission tomography, single-photon emission computed tomography, radionuclide imaging, cardiac magnetic resonance, and cardiac computed tomography/angiography), compared side by side for their applications in various clinical scenarios. Ninety-five clinical scenarios were developed from eight selected pre-existing guidelines and classified into four sections as follows: 1) detection of coronary artery disease, symptomatic or asymptomatic; 2) cardiac evaluation in various clinical scenarios; 3) use of imaging modality according to prior testing; and 4) evaluation of cardiac structure and function. The clinical scenarios were scored by a separate rating committee on a scale of 1–9 to designate appropriate use, uncertain use, or inappropriate use according to a modified Delphi method. Overall, the AUC ratings for CT were higher than those of previous guidelines. These new AUC provide guidance for clinicians choosing among available testing modalities for various cardiac diseases and are also unique, given that most previous AUC for noninvasive imaging include only one imaging technique. As cardiac imaging is multimodal in nature, we believe that these AUC will be more useful for clinical decision making.

  14. Neurophysiology of functional imaging

    NARCIS (Netherlands)

    van Eijsden, Pieter; Hyder, Fahmeed; Rothman, Douglas L.; Shulman, Robert G.

    2009-01-01

    The successes of PET and fMRI in non-invasively localizing sensory functions had encouraged efforts to transform the subjective concepts of cognitive psychology into objective physical measures. The assumption was that mental functions could be decomposed into non-overlapping, context-independent

  15. Noninvasive electrocardiographic imaging of chronic myocardial infarct scar§

    Science.gov (United States)

    Horáček, B. Milan; Wang, Linwei; Dawoud, Fady; Xu, Jingjia; Sapp, John L.

    2015-01-01

    Background Myocardial infarction (MI) scar constitutes a substrate for ventricular tachycardia (VT), and an accurate delineation of infarct scar may help to identify reentrant circuits and thus facilitate catheter ablation. One of the recent advancements in characterization of a VT substrate is its volumetric delineation within the ventricular wall by noninvasive electrocardiographic imaging. This paper compares, in four specific cases, epicardial and volumetric inverse solutions, using magnetic resonance imaging (MRI) with late gadolinium enhancement as a gold standard. Methods For patients with chronic MI, who presented at Glasgow Western Infirmary, delayed-enhancement MRI and 120-lead body surface potential mapping (BSPM) data were acquired and 4 selected cases were later made available to a wider community as part of the 2007 PhysioNet/Computers in Cardiology Challenge. These data were used to perform patient-specific inverse solutions for epicardial electrograms and morphology-based criteria were applied to delineate infarct scar on the epicardial surface. Later, the Rochester group analyzed the same data by means of a novel inverse solution for reconstructing intramural transmembrane potentials, to delineate infarct scar in three dimensions. Comparison of the performance of three specific inverse-solution algorithms is presented here, using scores based on the 17-segment ventricular division scheme recommended by the American Heart Association. Results The noninvasive methods delineating infarct scar as three-dimensional (3D) intramural distribution of transmembrane action potentials outperform estimates providing scar delineation on the epicardial surface in all scores used for comparison. In particular, the extent of infarct scar (its percentage mass relative to the total ventricular mass) is rendered more accurately by the 3D estimate. Moreover, the volumetric rendition of scar border provides better clues to potential targets for catheter ablation

  16. Insights into Parkinson's disease models and neurotoxicity using non-invasive imaging

    International Nuclear Information System (INIS)

    Sanchez-Pernaute, Rosario; Brownell, Anna-Liisa; Jenkins, Bruce G.; Isacson, Ole

    2005-01-01

    Loss of dopamine in the nigrostriatal system causes a severe impairment in motor function in patients with Parkinson's disease and in experimental neurotoxic models of the disease. We have used non-invasive imaging techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (MRI) to investigate in vivo the changes in the dopamine system in neurotoxic models of Parkinson's disease. In addition to classic neurotransmitter studies, in these models, it is also possible to characterize associated and perhaps pathogenic factors, such as the contribution of microglia activation and inflammatory responses to neuronal damage. Functional imaging techniques are instrumental to our understanding and modeling of disease mechanisms, which should in turn lead to development of new therapies for Parkinson's disease and other neurodegenerative disorders

  17. Non-invasive cardiac imaging. Spectrum, methodology, indication and interpretation

    International Nuclear Information System (INIS)

    Schaefers, Michael; Flachskampf, Frank; Sechtem, Udo; Achenbach, Stephan; Krause, Bernd J.; Schwaiger, Markus; Breithardt, Guenter

    2008-01-01

    The book contains 13 contributions concerning the following chapters: (1)methodology: echo cardiography; NMR imaging; nuclear medicine; computer tomography, (2) clinical protocols: contraction; cardiac valve function; perfusion and perfusion reserve; vitality; corona imaging; transmitters, receptors, enzymes; (3) clinic: coronary heart diseases; non-ischemic heart diseases. The appendix contains two contributions on future developments and certification/standardization

  18. Assays for noninvasive imaging of reporter gene expression

    International Nuclear Information System (INIS)

    Gambhir, S.S.; Barrio, J.R.; Herschman, H.R.; Phelps, M.E.

    1999-01-01

    Repeated, noninvasive imaging of reporter gene expression is emerging as a valuable tool for monitoring the expression of genes in animals and humans. Monitoring of organ/cell transplantation in living animals and humans, and the assessment of environmental, behavioral, and pharmacologic modulation of gene expression in transgenic animals should soon be possible. The earliest clinical application is likely to be monitoring human gene therapy in tumors transduced with the herpes simplex virus type 1 thymidine kinase (HSV1-tk) suicide gene. Several candidate assays for imaging reporter gene expression have been studied, utilizing cytosine deaminase (CD), HSV1-tk, and dopamine 2 receptor (D2R) as reporter genes. For the HSV1-tk reporter gene, both uracil nucleoside derivatives (e.g., 5-iodo-2'-fluoro-2'-deoxy-1-β-D-arabinofuranosyl-5-iodouracil [FIAU] labeled with 124 I, 131 I ) and acycloguanosine derivatives {e.g., 8-[ 18 F]fluoro-9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine (8-[ 18 F]-fluoroganciclovir) ([ 18 F]FGCV), 9-[(3-[ 18 F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([ 18 F]FHPG)} have been investigated as reporter probes. For the D2R reporter gene, a derivative of spiperone {3-(2'-[ 18 F]-Fluoroethyl)spiperone ([ 18 F]FESP)} has been used with positron emission tomography (PET) imaging. In this review, the principles and specific assays for imaging reporter gene expression are presented and discussed. Specific examples utilizing adenoviral-mediated delivery of a reporter gene as well as tumors expressing reporter genes are discussed

  19. Noninvasive mapping of water diffusional exchange in the human brain using filter-exchange imaging.

    Science.gov (United States)

    Nilsson, Markus; Lätt, Jimmy; van Westen, Danielle; Brockstedt, Sara; Lasič, Samo; Ståhlberg, Freddy; Topgaard, Daniel

    2013-06-01

    We present the first in vivo application of the filter-exchange imaging protocol for diffusion MRI. The protocol allows noninvasive mapping of the rate of water exchange between microenvironments with different self-diffusivities, such as the intracellular and extracellular spaces in tissue. Since diffusional water exchange across the cell membrane is a fundamental process in human physiology and pathophysiology, clinically feasible and noninvasive imaging of the water exchange rate would offer new means to diagnose disease and monitor treatment response in conditions such as cancer and edema. The in vivo use of filter-exchange imaging was demonstrated by studying the brain of five healthy volunteers and one intracranial tumor (meningioma). Apparent exchange rates in white matter range from 0.8±0.08 s(-1) in the internal capsule, to 1.6±0.11 s(-1) for frontal white matter, indicating that low values are associated with high myelination. Solid tumor displayed values of up to 2.9±0.8 s(-1). In white matter, the apparent exchange rate values suggest intra-axonal exchange times in the order of seconds, confirming the slow exchange assumption in the analysis of diffusion MRI data. We propose that filter-exchange imaging could be used clinically to map the water exchange rate in pathologies. Filter-exchange imaging may also be valuable for evaluating novel therapies targeting the function of aquaporins. Copyright © 2012 Wiley Periodicals, Inc.

  20. Neurophysiology of functional imaging.

    Science.gov (United States)

    van Eijsden, Pieter; Hyder, Fahmeed; Rothman, Douglas L; Shulman, Robert G

    2009-05-01

    The successes of PET and fMRI in non-invasively localizing sensory functions had encouraged efforts to transform the subjective concepts of cognitive psychology into objective physical measures. The assumption was that mental functions could be decomposed into non-overlapping, context-independent modules that are operated on by separable areas of a computer-like brain. The failures of cognitive modularity and of a very localized phrenology are generally, but not universally, accepted; but in their place, and usually not distinguished from the original revolutionary hopes of clarification, experimental results are being interpreted in terms of rather flexible definitions of both cognitive concepts and the degree of localization. In an alternative approach, we have connected fMRI, (13)C MRS, and electrophysiology measurements of brain energy to connect with observable properties of mental life (i.e., awareness). We illustrate this approach with a sensory stimulation experiment; the degree of localization found in BOLD signals was related to the global energy of the brain which, when manipulated by anesthetics, affected the degree of awareness. The influence of brain energy upon functional imaging maps is changing the interpretations of neuroimaging experiments, from psychological concepts generating computer-like responses to empirical responses dominated by the high brain energy and signaling at rest. In our view "baseline" is an operational term, an adjective that defines a property of a state of the system before it is perturbed by a stimulus. Given the dependence of observable psychological properties upon the "baseline" energy, we believe that it is unnecessarily limiting to define a particular state as the baseline.

  1. 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

  2. Non-invasive measurements of granular flows by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, M.; Altobelli, S.A.; Caprihan, A.; Fukushima, E.; Jeong, E.K.

    1993-01-20

    Magnetic Resonance Imaging (MRI) was used to measure granular-flow in a partially filled, steadily rotating, long, horizontal cylinder. This non-invasive technique can yield statistically averaged two-dimensional concentrations and velocity profiles anywhere in the flow of suitable granular materials. First, rigid body motion of a cylinder fill with granular material was studied to confirm the validity of this method. Then, the density variation of the flowing layer where particles collide and dilate, and the depth of the flowing layer and the flow velocity profile were obtained as a function of the cylinder rotation rate.

  3. 5th German cardiodiagnostic meeting 2013 with the 6th Leipzig Symposium on non-invasive cardiovascular imaging. Challenges and limit of the non-invasive cardiac imaging

    International Nuclear Information System (INIS)

    2013-01-01

    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.

  4. Estimating Trabecular Bone Mechanical Properties From Non-Invasive Imaging

    Science.gov (United States)

    Hogan, Harry A.; Webster, Laurie

    1997-01-01

    An important component in developing countermeasures for maintaining musculoskeletal integrity during long-term space flight is an effective and meaningful method of monitoring skeletal condition. Magnetic resonance imaging (MRI) is an attractive non-invasive approach because it avoids the exposure to radiation associated with X-ray based imaging and also provides measures related to bone microstructure rather than just density. The purpose of the research for the 1996 Summer Faculty Fellowship period was to extend the usefulness of the MRI data to estimate the mechanical properties of trabecular bone. The main mechanical properties of interest are the elastic modulus and ultimate strength. Correlations are being investigated between these and fractal analysis parameters, MRI relaxation times, apparent densities, and bone mineral densities. Bone specimens from both human and equine donors have been studied initially to ensure high-quality MR images. Specimens were prepared and scanned from human proximal tibia bones as well as the equine distal radius. The quality of the images from the human bone appeared compromised due to freezing artifact, so only equine bone was included in subsequent procedures since these specimens could be acquired and imaged fresh before being frozen. MRI scans were made spanning a 3.6 cm length on each of 5 equine distal radius specimens. The images were then sent to Dr. Raj Acharya of the State University of New York at Buffalo for fractal analysis. Each piece was cut into 3 slabs approximately 1.2 cm thick and high-resolution contact radiographs were made to provide images for comparing fractal analysis with MR images. Dual energy X-ray absorptiometry (DEXA) scans were also made of each slab for subsequent bone mineral density determination. Slabs were cut into cubes for mechanical using a slow-speed diamond blade wafering saw (Buehler Isomet). The dimensions and wet weights of each cube specimen were measured and recorded. Wet weights

  5. Current Perspectives on In Vivo Noninvasive Tracking of Extracellular Vesicles with Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Prakash Gangadaran

    2017-01-01

    Full Text Available Clinical and preclinical in vivo tracking of extracellular vesicles (EVs are a crucial tool for the development and optimization of EV-based diagnosis and treatment. EVs have gained interest due to their unique properties that make them excellent candidates for biological applications. Noninvasive in vivo EV tracking has allowed marked progress towards elucidating the mechanisms and functions of EVs in real time in preclinical and clinical studies. In this review, we summarize several molecular imaging methods that deal with EVs derived from different cells, which have allowed investigations of EV biodistribution, as well as their tracking, delivery, and tumor targeting, to determine their physiological functions and to exploit imaging-derived information for EV-based theranostics.

  6. Noninvasive monitoring of adrenocortical function in captive jaguars (Panthera onca).

    Science.gov (United States)

    Conforti, Valéria A; Morato, Ronaldo G; Augusto, Anderson M; de Oliveira e Sousa, Lúcio; de Avila, David M; Brown, Janine L; Reeves, Jerry J

    2012-01-01

    Jaguars are threatened with extinction throughout their range. A sustainable captive population can serve as a hedge against extinction, but only if they are healthy and reproduce. Understanding how jaguars respond to stressors may help improve the captive environment and enhance their wellbeing. Thus, our objectives were to: (1) conduct an adrenocorticotrophic hormone (ACTH) challenge to validate a cortisol radioimmunoassay (RIA) for noninvasive monitoring of adrenocortical function in jaguars; (2) investigate the relationship between fecal corticoid (FCM) and androgen metabolite (FAM) concentrations in males during the ACTH challenge; and (3) establish a range of physiological concentrations of FCMs for the proposed protocol. Seven jaguars (3 M, 4 F) received 500 IU/animal of ACTH. Pre- and post-ACTH fecal samples were assayed for corticoid (M and F) and androgen metabolites (M) by RIA. Concentrations of FCMs increased (P80.01) after ACTH injection (pre-ACTH: 0.90 ± 0.12 µg/g dry feces; post-ACTH: 2.55 ± 0.25 µg/g). Considering pre- and post-ACTH samples, FCM concentrations were higher (P80.01) in males (2.15 ± 0.20 µg/g) than in females (1.30 ± 0.20 µg/g), but the magnitude of the response to ACTH was comparable (P>0.05) between genders. After ACTH injection, FAMs increased in two (of 3) males; in one male, FCMs and FAMs were positively correlated (0.60; P80.01). Excretion of FCMs was assessed in 16 jaguars (7 M, 9 F) and found to be highly variable (range, 80.11-1.56 µg/g). In conclusion, this study presents a cortisol RIA for monitoring adrenocortical function in jaguars noninvasively. © 2011 Wiley Periodicals, Inc.

  7. 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.)

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

    International Nuclear Information System (INIS)

    Jodal, Andreas; Behe, Martin; Schibli, Roger

    2017-01-01

    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.)

  9. 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...

  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. Imaging modalities for the non-invasive diagnosis of endometriosis.

    Science.gov (United States)

    Nisenblat, Vicki; Bossuyt, Patrick M M; Farquhar, Cindy; Johnson, Neil; Hull, M Louise

    2016-02-26

    About 10% of women of reproductive age suffer from endometriosis. Endometriosis is a costly chronic disease that causes pelvic pain and subfertility. Laparoscopy, the gold standard diagnostic test for endometriosis, is expensive and carries surgical risks. Currently, no non-invasive tests that can be used to accurately diagnose endometriosis are available in clinical practice. This is the first review of diagnostic test accuracy of imaging tests for endometriosis that uses Cochrane methods to provide an update on the rapidly expanding literature in this field. • To provide estimates of the diagnostic accuracy of imaging modalities for the diagnosis of pelvic endometriosis, ovarian endometriosis and deeply infiltrating endometriosis (DIE) versus surgical diagnosis as a reference standard.• To describe performance of imaging tests for mapping of deep endometriotic lesions in the pelvis at specific anatomical sites.Imaging tests were evaluated as replacement tests for diagnostic surgery and as triage tests that would assist decision making regarding diagnostic surgery for endometriosis. We searched the following databases to 20 April 2015: MEDLINE, CENTRAL, EMBASE, CINAHL, PsycINFO, Web of Science, LILACS, OAIster, TRIP, ClinicalTrials.gov, MEDION, DARE, and PubMed. Searches were not restricted to a particular study design or language nor to specific publication dates. The search strategy incorporated words in the title, abstracts, text words across the record and medical subject headings (MeSH). We considered published peer-reviewed cross-sectional studies and randomised controlled trials of any size that included prospectively recruited women of reproductive age suspected of having one or more of the following target conditions: endometrioma, pelvic endometriosis, DIE or endometriotic lesions at specific intrapelvic anatomical locations. We included studies that compared the diagnostic test accuracy of one or more imaging modalities versus findings of surgical

  12. Theranostic Iron Oxide/Gold Ion Nanoprobes for MR Imaging and Noninvasive RF Hyperthermia.

    Science.gov (United States)

    Fazal, Sajid; Paul-Prasanth, Bindhu; Nair, Shantikumar V; Menon, Deepthy

    2017-08-30

    This work focuses on the development of a nanoparticulate system that can be used for magnetic resonance (MR) imaging and E-field noninvasive radiofrequency (RF) hyperthermia. For this purpose, an amine-functional gold ion complex (GIC), [Au(III)(diethylenetriamine)Cl]Cl 2 , which generates heat upon RF exposure, was conjugated to carboxyl-functional poly(acrylic acid)-capped iron-oxide nanoparticles (IO-PAA NPs) to form IO-GIC NPs of size ∼100 nm. The multimodal superparamagnetic IO-GIC NPs produced T2-contrast on MR imaging and unlike IO-PAA NPs generated heat on RF exposure. The RF heating response of IO-GIC NPs was found to be dependent on the RF power, exposure period, and particle concentration. IO-GIC NPs at a concentration of 2.5 mg/mL showed a high heating response (δT) of ∼40 °C when exposed to 100 W RF power for 1 min. In vitro cytotoxicity measurements on NIH-3T3 fibroblast cells and 4T1 cancer cells showed that IO-GIC NPs are cytocompatible at high NP concentrations for up to 72 h. Upon in vitro RF exposure (100 W, 1 min), a high thermal response leads to cell death of 4T1 cancer cells incubated with IO-GIC NPs (1 mg/mL). Hematoxylin and eosin imaging of rat liver tissues injected with 100 μL of 2.5 mg/mL IO-GIC NPs and exposed to low RF power of 20 W for 10 min showed significant loss of tissue morphology at the site of injection, as against RF-exposed or nanoparticle-injected controls. In vivo MR imaging and noninvasive RF exposure of 4T1-tumor-bearing mice after IO-GIC NP administration showed T2 contrast enhancement and a localized generation of high temperatures in tumors, leading to tumor tissue damage. Furthermore, the administration of IO-GIC NPs followed by RF exposure showed no adverse acute toxicity effects in vivo. Thus, IO-GIC NPs show good promise as a theranostic agent for magnetic resonance imaging and noninvasive RF hyperthermia for cancer.

  13. Imaging modalities for the non-invasive diagnosis of endometriosis

    NARCIS (Netherlands)

    Nisenblat, Vicki; Bossuyt, Patrick M. M.; Farquhar, Cindy; Johnson, Neil; Hull, M. Louise

    2016-01-01

    About 10% of women of reproductive age suffer from endometriosis. Endometriosis is a costly chronic disease that causes pelvic pain and subfertility. Laparoscopy, the gold standard diagnostic test for endometriosis, is expensive and carries surgical risks. Currently, no non-invasive tests that can

  14. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  15. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

  16. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

  17. Noninvasive Corneal Image-Based Gaze Measurement System

    OpenAIRE

    Chong, Eunji; Nitschke, Christian; Nakazawa, Atsushi; Rozga, Agata; Rehg, James M.

    2017-01-01

    Gaze tracking is an important technology as the system can give information about a person from what and where the person is seeing. There have been many attempts to make robust and accurate gaze trackers using either monitor or wearable devices. However, those contraptions often require fine individual calibration per session and/or require a person wearing a device, which may not be suitable for certain situations. In this paper, we propose a robust and a completely noninvasive gaze trackin...

  18. The potential for non-invasive brain stimulation to improve function after amputation.

    Science.gov (United States)

    G Hordacre, Brenton; C Ridding, Michael; V Bradnam, Lynley

    2016-07-01

    Lower limb amputee rehabilitation has traditionally focussed on restoration of gait and balance through use of prosthetic limbs and mobility aids. Despite these efforts, some amputees continue to experience difficulties with mastering prosthetic mobility. Emerging techniques in rehabilitation, such as non-invasive brain stimulation (NIBS), may be an appropriate tool to enhance prosthetic rehabilitation outcomes by promoting "normal" brain reorganisation and function. The purpose of this review is to highlight the potential of NIBS to improve functional outcomes for lower limb amputees. To demonstrate the rationale for applying NIBS to amputees, this study will first review literature regarding human motor control of gait, followed by neurophysiological reorganisation of the motor system after amputation and the relationship between brain reorganisation and gait function. We will conclude by reviewing literature demonstrating application of NIBS to lower limb muscle representations and evidence supportive of subsequent functional improvements. Imaging, brain stimulation and behavioural evidence indicate that the cortex contributes to locomotion in humans. Following amputation both hemispheres reorganise with evidence suggesting brain reorganisation is related to functional outcomes in amputees. Previous studies indicate that brain stimulation techniques can be used to selectively promote neuroplasticity of lower limb cortical representations with improvements in function. We suggest NIBS has the potential to transform lower limb amputee rehabilitation and should be further investigated. Implications for Rehabilitation Despite extensive rehabilitation some amputees continue to experience difficulty with prosthetic mobility Brain reorganisation following amputation has been related to functional outcomes and may be an appropriate target for novel interventions Non-invasive brain stimulation is a promising tool which has potential to improve functional outcomes for

  19. 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

  20. Noninvasive optical imaging of resistance training adaptations in human muscle

    Science.gov (United States)

    Warren, Robert V.; Cotter, Joshua; Ganesan, Goutham; Le, Lisa; Agustin, Janelle P.; Duarte, Bridgette; Cutler, Kyle; O'Sullivan, Thomas; Tromberg, Bruce J.

    2017-12-01

    A quantitative and dynamic analysis of skeletal muscle structure and function can guide training protocols and optimize interventions for rehabilitation and disease. While technologies exist to measure body composition, techniques are still needed for quantitative, long-term functional imaging of muscle at the bedside. We evaluate whether diffuse optical spectroscopic imaging (DOSI) can be used for long-term assessment of resistance training (RT). DOSI measures of tissue composition were obtained from 12 adults before and after 5 weeks of training and compared to lean mass fraction (LMF) from dual-energy X-ray absorptiometry (DXA). Significant correlations were detected between DXA LMF and DOSI-measured oxy-hemo/myoglobin, deoxy-hemo/myoglobin, total-hemo/myoglobin, water, and lipid. RT-induced increases of ˜6% in oxy-hemo/myoglobin (3.4±1.0 μM, p=0.00314) and total-hemo/myoglobin (4.9±1.1 μM, p=0.00024) from the medial gastrocnemius were detected with DOSI and accompanied by ˜2% increases in lean soft tissue mass (36.4±12.4 g, p=0.01641) and ˜60% increases in 1 rep-max strength (41.5±6.2 kg, p = 1.9E-05). DOSI measures of vascular and/or muscle changes combined with correlations between DOSI and DXA suggest that quantitative diffuse optical methods can be used to evaluate body composition, provide feedback on long-term interventions, and generate new insight into training-induced muscle adaptations.

  1. Noninvasive imaging in vivo with fluorescent proteins from centimeters to micrometers

    Science.gov (United States)

    Yang, Meng; Jiang, Ping; Al-Zaid, Manal; Hoffman, Robert M.

    2008-02-01

    Whole-body imaging with fluorescent proteins has been shown to be a powerful technology with many applications in small animals. Our laboratory pioneered in vivo imaging with fluorescent proteins (1) including noninvasive whole-body imaging (2). Whole-body imaging with fluorescent proteins depends in large part on the brightness of the protein. Brighter, red-shifted proteins can make whole-body imaging more sensitive due to reduced absorption by tissues and less scatter. Non-invasive imaging with fluorescent proteins has been shown to be able to quantitatively track tumor growth and metastasis, gene expression, angiogenesis, and bacterial infection (3) even at subcellular resolution depending on the position of the cells in the animal. Interference by skin autofluorescence is kept to a minimum with the use of proper filters. To noninvasively image cancer cell/stromal cell interaction in the tumor microenvironment and drug response at the cellular level in live animals in real time, we developed a new imageable three-color animal model. The model consists of green fluorescent protein (GFP)-expressing mice transplanted with dual-color cancer cells labeled with GFP in the nucleus and red fluorescent protein (RFP) in the cytoplasm. Various in vivo phenomena of tumor-host interaction and cellular dynamics were imaged, including mitotic and apoptotic tumor cells, stromal cells interacting with the tumor cells, tumor vasculature, and tumor blood flow as well as drug response. This imageable technology should lead to many new insights of in vivo cancer cell biology.

  2. Application of optical coherence tomography and high-frequency ultrasound imaging during noninvasive laser vasectomy

    Science.gov (United States)

    Cilip, Christopher M.; Allaf, Mohamad E.; Fried, Nathaniel M.

    2012-04-01

    A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in six dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

  3. Noninvasive determination of burn depth in children by digital infrared thermal imaging

    Science.gov (United States)

    Medina-Preciado, Jose David; Kolosovas-Machuca, Eleazar Samuel; Velez-Gomez, Ezequiel; Miranda-Altamirano, Ariel; González, Francisco Javier

    2013-06-01

    Digital infrared thermal imaging is used to assess noninvasively the severity of burn wounds in 13 pediatric patients. A delta-T (ΔT) parameter obtained by subtracting the temperature of a healthy contralateral region from the temperature of the burn wound is compared with the burn depth measured histopathologically. Thermal imaging results show that superficial dermal burns (IIa) show increased temperature compared with their contralateral healthy region, while deep dermal burns (IIb) show a lower temperature than their contralateral healthy region. This difference in temperature is statistically significant (pburns. These results show that digital infrared thermal imaging could be used as a noninvasive procedure to assess burn wounds. An additional advantage of using thermal imaging, which can image a large skin surface area, is that it can be used to identify regions with different burn depths and estimate the size of the grafts needed for deep dermal burns.

  4. Integration of non-invasive functional assessments with anatomical risk stratification in complex coronary artery disease: the non-invasive functional SYNTAX score.

    Science.gov (United States)

    Collet, Carlos; Onuma, Yoshinobu; Miyazaki, Yosuke; Morel, Marie-Angèle; Serruys, Patrick W

    2017-04-01

    Since the early days of coronary angiography, the extension and severity of coronary artery disease (CAD) have been used for risk stratification. The SYNTAX score objectively characterizes CAD in patients with multivessel disease. Furthermore, recalculating the SYNTAX score by the incorporation of the functional component coronary stenosis (i.e., FFR) increases the discrimination for the risk of adverse events. The calculation of the SYNTAX score derived from non-invasive modalities such as coronary computed tomography angiography (CTA) has emerged as a mean to obtain the SYNTAX score before invasive cardiac catheterization. Likewise, the computation of the non-invasive fractional flow reserve CT (FFR CT ) allows for the calculation of the non-invasive functional SYNTAX score. Ultimately, the combination of anatomical and functional evaluations with clinical factors further refines the identification of patients at risk and provides a recommendation for the Heart Team regarding the treatment strategy (i.e., PCI or CABG) based on the predicted 4-year mortality. The purpose of this review is to describe the integration of a novel non-invasive functional coronary assessment with the angiographic risk score in patients with multivessel CAD.

  5. Non-invasive vascular imaging in perforator flap surgery

    International Nuclear Information System (INIS)

    Saba, Luca; Piga, Mario; Atzeni, Matteo; Ribuffo, Diego; Rozen, Warren Matthew; Alonso-Burgos, Alberto; Bura, Raffaella

    2013-01-01

    Preoperative imaging using a range of imaging modalities has become increasingly popular for preoperative planning in plastic surgery, in particular in perforator flap surgery. Modalities in this role include ultrasound (US), magnetic resonance angiography (MRA), and computed tomographic angiography (CTA). The evidence for the use of these techniques has been reported in only a handful of studies. In this paper we conducted a non-systematic review of the literature to establish the role for each of these modalities. The role of state-of-the-art vascular imaging as an application in perforator flap surgery is thus offered

  6. Non-invasive vascular imaging in perforator flap surgery

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Piga, Mario [Dept. of Radiology, Azienda Ospedaliero Univ. (AOU), di Cagliari-Polo di Monserrato, Cagliari (Italy)], e-mail: lucasaba@tiscali.it; Atzeni, Matteo; Ribuffo, Diego [Dept. of Surgery, Section of Plastic Surgery, Azienda Ospedaliero Univ. (AOU), di Cagliari-Polo di Monserrato, Cagliari (Italy); Rozen, Warren Matthew [Jack Brockhov Reconstructive Plastic Surgery Research Unit, Dept. of Anatomy and Cell Biology, The Univ. of Melbourne, Parkville, Victoria (Australia); Alonso-Burgos, Alberto [Dept. of Radiology, Clinica Univ., Univ. de Navarra, Pamplona (Spain); Bura, Raffaella [Dept. of Surgery, Section of Vascular Surgery, Azienda Ospedaliero Univ. (AOU), di Cagliari-Polo di Monserrato, Cagliari (Italy)

    2013-02-15

    Preoperative imaging using a range of imaging modalities has become increasingly popular for preoperative planning in plastic surgery, in particular in perforator flap surgery. Modalities in this role include ultrasound (US), magnetic resonance angiography (MRA), and computed tomographic angiography (CTA). The evidence for the use of these techniques has been reported in only a handful of studies. In this paper we conducted a non-systematic review of the literature to establish the role for each of these modalities. The role of state-of-the-art vascular imaging as an application in perforator flap surgery is thus offered.

  7. Structural and functional imaging: Particularities in children

    Energy Technology Data Exchange (ETDEWEB)

    Chiron, C.; Hertz-Pannier, L. [Hop Necker Enfants Malad, INSERM, Serv Neuropediat, U663, F-75015 Paris (France); Chiron, C.; Hertz-Pannier, L. [UnivParis 05, F-75005 Paris (France); Chiron, C.; Hertz-Pannier, L. [CEA, I2BM, Neurospin, SHFJ, F-91191 Orsay (France)

    2008-07-01

    Surgery of partial epilepsies in childhood has largely benefited from the recent advances of imaging techniques, which carry a triple goal: (1) to contribute to the localization of the epilepsy onset zone, (2) to detect and delineate an underlying lesion, and (3) to study the spatial relationship between the epileptogenic zone and the neighboring functional cortex, in order to select patients and plan the resection. This noninvasive pre-surgical imaging workup must be compared to clinical and electrical data to estimate the postoperative prognosis, while invasive techniques such as SEEG, cortical stimulations, and IAT often remain indispensable in difficult cases, i.e., in cryptogenic epilepsies. As in adults, advances in MRI allow us to detect more and more subtle underlying lesions, but this requires repeating MR studies during early childhood and using adapted sequence parameters to account for ongoing myelination. Ictal SPECT and PET imaging prove especially useful in planning depth electrode placement when video-EEG is not contributive, when MRI looks normal or shows multiple abnormalities, or in cases of discrepant findings. Multimodal imaging greatly enhances the sensitivity of all of these techniques. Finally, functional MRI of motor and language functions provide noninvasive cortical mapping of essential functions, using age-adapted paradigms, in cooperating children from age five to six and from IQs around 60. (authors)

  8. Rational targeting of the urokinase receptor (uPAR): development of antagonists and non-invasive imaging probes

    DEFF Research Database (Denmark)

    Kriegbaum, M C; Persson, M; Haldager, L

    2011-01-01

    -ray crystallography and surface plasmon resonance studies. Importantly, these structural studies also define possible druggable target sites in uPAR for small molecules and provide guidelines for the development of reporter groups applicable for non-invasive molecular imaging of uPAR expression in vivo by positron...... emission tomography. In this review, we will discuss recent advances in our perception of the structure-function relationships of uPAR ligation and how these may assist translational research in preclinical intervention studies of uPAR function....

  9. A Novel Multivoxel-Based Quantitation of Metabolites and Lipids Noninvasively Combined with Diffusion-Weighted Imaging in Breast Cancer

    Science.gov (United States)

    2012-09-01

    invasive lobular cancer), twenty patients with benign breast tumor ( fibroadenoma , proliferative fibrocystic change and papillomas) will be...Metabolites and Lipids Noninvasively Combined with Diffusion-Weighted Imaging in Breast Cancer PRINCIPAL INVESTIGATOR: Michael Albert Thomas...5a. CONTRACT NUMBER Noninvasively Combined with Diffusion-Weighted Imaging in Breast Cancer 5b. GRANT NUMBER W81XWH-10-1-0743 5c. PROGRAM

  10. 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

  11. 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...

  12. Noninvasive multiphoton imaging of cardiovascular structures using NIR femtosecond laser scanning microscopy

    Science.gov (United States)

    Schenke-Layland, Katja; Riemann, Iris; Stock, Ulrich A.; Konig, Karsten

    2004-07-01

    Near infrared (NIR) femtosecond laser scanning microscopy represents a novel and very promising medical diagnostic imaging technology for non-invasive cross-sectional analysis of living biological tissues. In this study multiphoton imaging has been performed to analyze the structural features of extracellular matrix (ECM) components, e.g. collagen and elastin, of living pulmonary and aortic heart valves. High-resolution autofluorescence and second harmonic generation (SHG) images of collagenous and elastic fibers were demonstrated using multifluorophore, multiphoton excitation at two different wavelengths and non-invasive optical sectioning, without the need of embedding or staining. The quality of the resulting three-dimensional images allowed exact differentiation of the ECM components. These experimental results indicated that NIR femtosecond laser scanning microscopy may prove to be a useful tool for the non-destructive monitoring and characterization of cardiovascular structures.

  13. Noninvasive Ph-telemetric Measurement of Gastrointestinal Function

    Science.gov (United States)

    Tietze, Karen J.

    1991-01-01

    The purpose of this study was to gain experience with and validate the Heidelberg pH-telemetric methodology in order to determine if the pH-telemetric methodology would be a useful noninvasive measure of gastrointestinal transit time for future ground-based and in-flight drug evaluation studies. The Heidelberg pH metering system is a noninvasive, nonradioactive telemetric system that, following oral ingestion, continuously measures intraluminal pH of the stomach, duodenum, small bowel, ileocecal junction, and large bowel. Gastrointestinal motility profiles were obtained in normal volunteers using the lactulose breath-hydrogen and Heidelberg pH metering techniques. All profiles were obtained in the morning after an overnight fast. Heidelberg pH profiles were obtained in the fasting and fed states; lactulose breath-hydrogen profiles were obtained after a standard breakfast. Mouth-to-cecum transit time was measured as the interval from administration of lactulose (30 ml; 20 g) to a sustained increase in breath-hydrogen of 10 ppm or more. Gastric emptying time was measured as the interval from the administration of the Heidelberg capsule to a sustained increase in pH of three units or more.

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

    Science.gov (United States)

    2016-12-01

    shows that two-thirds of cancers have no genetic or environmental predisposition .25 This highlights the importance of noninvasive screening measures...oncologic imaging, such as prostate, liver, and breast cancer , andwe briefly present some preliminary data in prostate cancer at the end of "clinical...magnetic resonance imaging (MRI) is an emer- ging diagnostic tool for the screening, staging and treatment of prostate cancer (PCa).1–17 However

  15. Imaging Modalities for the Noninvasive Assessment of Fibrosis in Crohn's Disease

    Science.gov (United States)

    Stasi, Cristina; Falchini, Massimo; Milani, Stefano

    2012-01-01

    The development of strictures in Crohn's disease is a main cause of hospitalization and often represent an indication for surgery. The differentiation between inflammatory and fibrotic strictures is useful to determine the optimal treatment. Today, the availability of noninvasive methods to assess the presence and extension of strictures offers new tools for the diagnosis and follow-up of the disease. Bowel ultrasound, power doppler ultrasound, contrast-enhanced ultrasound, magnetic resonance imaging offer the additional advantage that they do not expose patients to ionizing radiation. In this paper we provide an update on the accuracy of these noninvasive methods for the diagnosis of Crohn's disease. PMID:22654607

  16. Imaging Modalities for the Noninvasive Assessment of Fibrosis in Crohn's Disease

    Directory of Open Access Journals (Sweden)

    Cristina Stasi

    2012-01-01

    Full Text Available The development of strictures in Crohn's disease is a main cause of hospitalization and often represent an indication for surgery. The differentiation between inflammatory and fibrotic strictures is useful to determine the optimal treatment. Today, the availability of noninvasive methods to assess the presence and extension of strictures offers new tools for the diagnosis and follow-up of the disease. Bowel ultrasound, power doppler ultrasound, contrast-enhanced ultrasound, magnetic resonance imaging offer the additional advantage that they do not expose patients to ionizing radiation. In this paper we provide an update on the accuracy of these noninvasive methods for the diagnosis of Crohn's disease.

  17. 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.

  18. An embedded system for image segmentation and multimodal registration in noninvasive skin cancer screening.

    Science.gov (United States)

    Diaz, Silvana; Soto, Javier E; Inostroza, Fabian; Godoy, Sebastian E; Figueroa, Miguel

    2017-07-01

    We present a heterogeneous architecture for image registration and multimodal segmentation on an embedded system for noninvasive skin cancer screening. The architecture combines Otsu thresholding and the random walker algorithm to perform image segmentation, and features a hardware implementation of the Harris corner detection algorithm to perform region-of-interest detection and image registration. Running on a Xilinx XC7Z020 reconfigurable system-on-a-chip, our prototype computes the initial segmentation of a 400×400-pixel region of interest in the visible spectrum in 12.1 seconds, and registers infrared images against this region at 540 frames per second, while consuming 1.9W.

  19. Noninvasive MR characterization of structural and functional components of reperfused infarct

    Energy Technology Data Exchange (ETDEWEB)

    Saeed, Maythem; Martin, Alastair J.; Saloner, David; Loi Do; Wilson, Mark (Dept. of Radiology and Biomedical Imaging, Univ. of California San Francisco, San Francisco, CA (United States)), e-mail: Maythem.Saeed@radiology.ucsf.edu

    2010-12-15

    Background: Left ventricular (LV) remodeling is a highly complex phenomenon that starts soon after infarction and progresses to extensive regional and global architectural changes over time. Purpose: To noninvasively comprehensively characterize transient (edema, hemorrhage, microvascular obstruction (MO)) and persistent structural (infarct size) components of reperfused infarct up to 10 weeks and to determine their relation to LV function. Material and Methods: Farm pigs were used for the study. Under fluoroscopy the left anterior descending (LAD) coronary artery was occluded for 90 min. MR imaging was performed at 3 days (n=14 pigs), 5 weeks (n=10), and 10 weeks (n=6) after reperfusion. The following MR imaging sequences were used: (i) cine; (ii) T2-weighted turbo spin echo; (iii) T2-weighted turbo spin echo; (iv) tagged; (v) phase-contrast velocity-encoded; (vi) first-pass perfusion; and (vii) delayed contrast-enhanced (DE-MR imaging). After imaging, animals were euthanized at 3 days (n=4), 5 weeks (n=4), and 10 weeks (n=6) and hearts were stained with triphenyltetrazolium chloride to define acute, subacute, and scar infarct and interstitial hemorrhage. Results: T2, T2, and DE-MR imaging demonstrated transient interstitial edema, interstitial hemorrhage, and MO, respectively. MO was observed in 85% of animals and 60% of these showed hemorrhages. Cine, tagged, and phase-contrast velocity-encoded images documented the persistent impairment in 3D strain of infarcted segments, which on first-pass perfusion showed persistent perfusion deficit. MR imaging demonstrated the progressive increase in LV volumes and decreased ejection fraction over time. The changes in LV between 5 and 10 weeks were not related to the presence of interstitial edema, interstitial hemorrhage, MO or increase in infarct size. Conclusion: The various MR sequences described in this study allowed the demonstration of transient and persistent components of reperfused infarct. The progressive

  20. Spectral-spatial classification for noninvasive cancer detection using hyperspectral imaging

    Science.gov (United States)

    Lu, Guolan; Halig, Luma; Wang, Dongsheng; Qin, Xulei; Chen, Zhuo Georgia; Fei, Baowei

    2014-01-01

    Abstract. Early detection of malignant lesions could improve both survival and quality of life of cancer patients. Hyperspectral imaging (HSI) has emerged as a powerful tool for noninvasive cancer detection and diagnosis, with the advantage of avoiding tissue biopsy and providing diagnostic signatures without the need of a contrast agent in real time. We developed a spectral-spatial classification method to distinguish cancer from normal tissue on hyperspectral images. We acquire hyperspectral reflectance images from 450 to 900 nm with a 2-nm increment from tumor-bearing mice. In our animal experiments, the HSI and classification method achieved a sensitivity of 93.7% and a specificity of 91.3%. The preliminary study demonstrated that HSI has the potential to be applied in vivo for noninvasive detection of tumors. PMID:25277147

  1. Non-invasive imaging of retinal blood flow in myeloproliferative neoplasms

    DEFF Research Database (Denmark)

    Willerslev, Anne; Hansen, Mathias M; Klefter, Oliver Niels

    2017-01-01

    . The retinopathy had resolved at follow-up in all patients. CONCLUSION: With non-invasive retinal imaging, we were able to demonstrate increased retinal venous blood velocity, increased retinal arterial blood oxygenation and normalization of intravascular reflectivity patterns after successful treatment......PURPOSE: To study the circulation in the retinal vessels in patients with blood dyscrasia due to myeloproliferative neoplasms using non-invasive retinal imaging. METHODS: Prospective consecutive case series of seven treatment-naïve patients with chronic myeloid leukaemia (n = 2), polycythemia vera...... (n = 4), essential thrombocytosis (n = 1) examined before and after cytoreductive treatment. We investigated retinal circulation with motion-contrast imaging, retinal oximetry and spectral-domain optical coherence tomography. RESULTS: Retinal venous blood velocity increased by 8.14% (CI95 3.67% to 12...

  2. 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.

  3. 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.

  4. Functional cardiac imaging: positron emission tomography

    International Nuclear Information System (INIS)

    Mullani, N.A.; Gould, K.L.

    1984-01-01

    Dynamic cardiovascular imaging plays a vital role in the diagnosis and treatment of cardiac disease by providing information about the function of the heart. During the past 30 years, cardiovascular imaging has evolved from the simple chest x-ray and fluoroscopy to such sophisticated techniques as invasive cardiac angiography and cinearteriography and, more recently, to noninvasive cardiac CT scanning, nuclear magnetic resonance, and positron emission tomography, which reflect more complex physiologic functions. As research tools, CT, NMR, and PET provide quantitative information on global as well as regional ventricular function, coronary artery stenosis, myocardial perfusion, glucose and fatty acid metabolism, or oxygen utilization, with little discomfort or risk to the patient. As imaging modalities become more sophisticated and more oriented toward clinical application, the prospect of routinely obtaining such functional information about the heart is becoming realistic. However, these advances are double-edged in that the interpretation of functional data is more complex than that of the anatomic imaging familiar to most physicians. They will require an enhanced understanding of the physiologic and biochemical processes, as well as of the instrumentation and techniques for analyzing the data. Of the new imaging modalities that provide functional information about the heart, PET is the most useful because it quantitates the regional distribution of radionuclides in vivo. Clinical applications, interpretation of data, and the impact of PET on our understanding of cardiac pathophysiology are discussed. 5 figures

  5. Non-invasive single-cell biomechanical analysis using live-imaging datasets.

    Science.gov (United States)

    Pearson, Yanthe E; Lund, Amanda W; Lin, Alex W H; Ng, Chee P; Alsuwaidi, Aysha; Azzeh, Sara; Gater, Deborah L; Teo, Jeremy C M

    2016-09-01

    The physiological state of a cell is governed by a multitude of processes and can be described by a combination of mechanical, spatial and temporal properties. Quantifying cell dynamics at multiple scales is essential for comprehensive studies of cellular function, and remains a challenge for traditional end-point assays. We introduce an efficient, non-invasive computational tool that takes time-lapse images as input to automatically detect, segment and analyze unlabeled live cells; the program then outputs kinematic cellular shape and migration parameters, while simultaneously measuring cellular stiffness and viscosity. We demonstrate the capabilities of the program by testing it on human mesenchymal stem cells (huMSCs) induced to differentiate towards the osteoblastic (huOB) lineage, and T-lymphocyte cells (T cells) of naïve and stimulated phenotypes. The program detected relative cellular stiffness differences in huMSCs and huOBs that were comparable to those obtained with studies that utilize atomic force microscopy; it further distinguished naïve from stimulated T cells, based on characteristics necessary to invoke an immune response. In summary, we introduce an integrated tool to decipher spatiotemporal and intracellular dynamics of cells, providing a new and alternative approach for cell characterization. © 2016. Published by The Company of Biologists Ltd.

  6. In-situ Non-Invasive Imaging of Liquid-Immersed Thin Film Composite Membranes

    KAUST Repository

    Ogieglo, Wojciech

    2017-10-14

    We present a non-invasive method to directly image liquid-immersed thin film composite membranes. The approach allows accessing information not only on the lateral distribution of the coating thickness, including variations in its swelling and density, but also on the distribution of substrate porosity, roughness, accessibility of pores to liquid, and even the degree of pore intrusion related to the thin layer deposition process. The method can be particularly helpful in the fields of functional coatings or membranes to allow laterally-resolved studies under realistic application conditions thereby opening completely new research avenues. The approach is demonstrated in a study of two polymers of intrinsic microporosity, PIM-1 and PIM-6FDA-OH, coated on polyacrylonitrile support and immersed in water. Variations of the skin morphology using different coating methods (floating, spin-coating and dip-coating) are evaluated with the help of the presented method. Surfaces of at least tens of cm2 can be potentially analyzed.

  7. Non-invasive imaging of atherosclerosis regression with magnetic resonance to guide drug development.

    Science.gov (United States)

    Raggi, Paolo; Baldassarre, Damiano; Day, Simon; de Groot, Eric; Fayad, Z A

    2016-08-01

    Slowing of progression and inducing the regression of atherosclerosis with medical therapy have been shown to be associated with an extensive reduction in risk of cardiovascular events. This proof of concept was obtained with invasive angiographic studies but these are, for obvious reasons, impractical for sequential investigations. Non-invasive imaging has henceforth replaced the more cumbersome invasive studies and has proven extremely valuable in numerous occasions. Because of excellent reproducibility and no radiation exposure, magnetic resonance imaging (MRI) has become the non-invasive method of choice to assess the efficacy of anti-atherosclerotic drugs. The high accuracy of this technology is particularly helpful in rare diseases where the small number of affected patients makes the conduct of outcome-trials in large cohorts impractical. With MRI it is possible to assess the extent, as well as the composition, of atherosclerotic plaques and this further enhances the utility of this technology. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. A Minimum Spanning Forest-Based Method for Noninvasive Cancer Detection With Hyperspectral Imaging.

    Science.gov (United States)

    Pike, Robert; Lu, Guolan; Wang, Dongsheng; Chen, Zhuo Georgia; Fei, Baowei

    2016-03-01

    The purpose of this paper is to develop a classification method that combines both spectral and spatial information for distinguishing cancer from healthy tissue on hyperspectral images in an animal model. An automated algorithm based on a minimum spanning forest (MSF) and optimal band selection has been proposed to classify healthy and cancerous tissue on hyperspectral images. A support vector machine classifier is trained to create a pixel-wise classification probability map of cancerous and healthy tissue. This map is then used to identify markers that are used to compute mutual information for a range of bands in the hyperspectral image and thus select the optimal bands. An MSF is finally grown to segment the image using spatial and spectral information. The MSF based method with automatically selected bands proved to be accurate in determining the tumor boundary on hyperspectral images. Hyperspectral imaging combined with the proposed classification technique has the potential to provide a noninvasive tool for cancer detection.

  9. 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.

  10. Non-Invasive Renal Perfusion Imaging Using Arterial Spin Labeling MRI: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Fabio Nery

    2018-01-01

    Full Text Available Tissue perfusion allows for delivery of oxygen and nutrients to tissues, and in the kidneys is also a key determinant of glomerular filtration. Quantification of regional renal perfusion provides a potential window into renal (patho physiology. However, non-invasive, practical, and robust methods to measure renal perfusion remain elusive, particularly in the clinic. Arterial spin labeling (ASL, a magnetic resonance imaging (MRI technique, is arguably the only available method with potential to meet all these needs. Recent developments suggest its viability for clinical application. This review addresses several of these developments and discusses remaining challenges with the emphasis on renal imaging in human subjects.

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

    OpenAIRE

    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 coronary artery calcium scoring, multi-slice computed tomography coronary angiography, conventional two-dimensional echocardiography and speckle-tracking echocardiography) for the diagnosis and ris...

  12. Noninvasive ergonovine maleate provocative testing for coronary artery spasm: the need for routine thallium-201 imaging

    International Nuclear Information System (INIS)

    Shanes, J.G.; Krone, R.J.; Fisher, K.; Shah, B.; Eisenkramer, G.; Humphrey, J.R.

    1983-01-01

    We administered ergonovine and used both electrocardiographic monitoring and thallium- 201 [ 201 Tl] imaging to detect reversible ischemia in 100 patients. Patients already established as having coronary artery spasm and those with nonbypassed, proximal, high-grade coronary artery stenosis were excluded. No complication occurred in any patient. The use of thallium imaging in addition to electrocardiographic monitoring resulted in a higher degree of sensitivity than did ECG monitoring alone. Fourteen patients demonstrated evidence of coronary artery spasm as documented by 201 Tl imaging but of the 14, significant ECG changes occurred in only 50%, and classic ST segment elevation in 21%. Thus, in carefully selected patients the noninvasive provocation of coronary spasm can be accomplished safely, but ECG monitoring must be combined with thallium- 201 imaging to achieve an acceptable degree of sensitivity

  13. Continuous non-invasive blood glucose monitoring by spectral image differencing method

    Science.gov (United States)

    Huang, Hao; Liao, Ningfang; Cheng, Haobo; Liang, Jing

    2018-01-01

    Currently, the use of implantable enzyme electrode sensor is the main method for continuous blood glucose monitoring. But the effect of electrochemical reactions and the significant drift caused by bioelectricity in body will reduce the accuracy of the glucose measurements. So the enzyme-based glucose sensors need to be calibrated several times each day by the finger-prick blood corrections. This increases the patient's pain. In this paper, we proposed a method for continuous Non-invasive blood glucose monitoring by spectral image differencing method in the near infrared band. The method uses a high-precision CCD detector to switch the filter in a very short period of time, obtains the spectral images. And then by using the morphological method to obtain the spectral image differences, the dynamic change of blood sugar is reflected in the image difference data. Through the experiment proved that this method can be used to monitor blood glucose dynamically to a certain extent.

  14. Nanomaterials for miRNA delivery and non-invasive imaging in cardiovascular regeneration

    Science.gov (United States)

    Gomes, Renata Sofia Mota

    The development of noninvasive platforms to assess cell fate after transplantation is of utmost importance in the context of Regenerative Medicine. Magnetic Resonance Imaging (MRI) is a powerful non-invasive imaging platform, heavily relying on the use of contrast agents, mostly nanoparticles (NPs). Gadolinium (Gd) and Superparamagnetic Iron Oxide (SPIO) NPs are contrast agents in clinical use, however these agents may cause liver toxicity, give rise to image artifacts in MRI, and typically have not been used as a drug delivery system. In this work, we developed a novel NP formulation containing fluorine to overcome the previous limitations. The NPs are based on poly(lactic-co-glycolic acid) (PLGA) which is a biocompatible and versatile polymer approved for human use . PLGA NPs containing fluorine were developed to label and track cells overtime and as vectors for microRNA (miR) delivery, which improves cell survival in hypoxic conditions. Herein we show that the fluorine-based NPs are a reliable approach to track non-invasively cells with clinical relevance (endothelial cells and cord-blood derived mononuclear cells) and simultaneously control the intracellular delivery of pro-survival and pro-angiogenic miRs. Also systems for in vitro and in vivo imaging via MRI of fluorine are developed and here explained. Furthermore in vivo studies are performed which show the therapeutic uses of such system. Additionally we also address the optimization of protocols for stem cell culture which may enhance proliferation and promote pluripotency in cardiac stem cells (CSCs) so as we can fully explore the potential of these cells in vivo using out novel theranostic NPs platform. We are the first authors developing and relating these novel developments.

  15. Detection of blood oxygen level by noninvasive passive spectral imaging of skin

    Science.gov (United States)

    Gupta, Neelam; Ramella-Roman, Jessica C.

    2008-02-01

    A compact optical hyperspectral imager that can detect both spectral and polarization signatures was used for passive noninvasive imaging of human skin. This vibration-insensitive imager uses an acousto-optic tunable filter (AOTF) as a spectral selection element and an electronically tunable liquid crystal variable retarder (LCVR) as a polarization device. Such an imager is ideally suited to provide both agile spectral and polarization signatures and can be readily used for real time in vivo medical imaging applications. Operation of this imager and image acquisition is fully computer controlled. This imager covers visible to near-infrared (VNIR) region from 400 to 800 nm with a 10 nm spectral resolution at 600 nm and uses a TeO II AOTF with a 15×15 mm2 linear aperture and a 4.2° angular aperture. At each wavelength 640×480 images with two orthogonal polarization are captured and a total of 41 spectral images are collected to form an image cube. A commercial Si CCD camera was used along with off-the-shelf lenses, mirrors and irises. We carried out experiments with a human subject and controlled the blood perfusion in the individual arm and finger by using a pressure cuff and a rubber band, respectively. Images were captured by illuminating the subject with a white light lamp source and imaging it from a distance. When the hyperspectral image analysis was performed we could observe the effects of skin deoxygenation. In this paper we will described our instrument, the experimental setup, the images obtained and the analysis results.

  16. Development of Noninvasive Classification Methods for Different Roasting Degrees of Coffee Beans Using Hyperspectral Imaging

    Directory of Open Access Journals (Sweden)

    Bingquan Chu

    2018-04-01

    Full Text Available This study aimed to develop an approach for quickly and noninvasively differentiating the roasting degrees of coffee beans using hyperspectral imaging (HSI. The qualitative properties of seven roasting degrees of coffee beans (unroasted, light, moderately light, light medium, medium, moderately dark, and dark were assayed, including moisture, crude fat, trigonelline, chlorogenic acid, and caffeine contents. These properties were influenced greatly by the respective roasting degree. Their hyperspectral images (874–1734 nm were collected using a hyperspectral reflectance imaging system. The spectra of the regions of interest were manually extracted from the HSI images. Then, principal components analysis was employed to compress the spectral data and select the optimal wavelengths based on loading weight analysis. Meanwhile, the random frog (RF methodology and the successive projections algorithm were also adopted to pick effective wavelengths from the spectral data. Finally, least squares support vector machine (LS-SVM was utilized to establish discriminative models using spectral reflectance and corresponding labeled classes for each degree of roast sample. The results showed that the LS-SVM model, established by the RF selecting method, with eight wavelengths performed very well, achieving an overall classification accuracy of 90.30%. In conclusion, HSI was illustrated as a potential technique for noninvasively classifying the roasting degrees of coffee beans and might have an important application for the development of nondestructive, real-time, and portable sensors to monitor the roasting process of coffee beans.

  17. 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.)

  18. A review of non-invasive imaging methods and applications in contaminant hydrogeology research.

    Science.gov (United States)

    Werth, Charles J; Zhang, Changyong; Brusseau, Mark L; Oostrom, Mart; Baumann, Thomas

    2010-04-01

    Contaminant hydrogeological processes occurring in porous media are typically not amenable to direct observation. As a result, indirect measurements (e.g., contaminant breakthrough at a fixed location) are often used to infer processes occurring at different scales, locations, or times. To overcome this limitation, non-invasive imaging methods are increasingly being used in contaminant hydrogeology research. Four of the most common methods, and the subjects of this review, are optical imaging using UV or visible light, dual-energy gamma radiation, X-ray microtomography, and magnetic resonance imaging (MRI). Non-invasive imaging techniques have provided valuable insights into a variety of complex systems and processes, including porous media characterization, multiphase fluid distribution, fluid flow, solute transport and mixing, colloidal transport and deposition, and reactions. In this paper we review the theory underlying these methods, applications of these methods to contaminant hydrogeology research, and methods' advantages and disadvantages. As expected, there is no perfect method or tool for non-invasive imaging. However, optical methods generally present the least expensive and easiest options for imaging fluid distribution, solute and fluid flow, colloid transport, and reactions in artificial two-dimensional (2D) porous media. Gamma radiation methods present the best opportunity for characterization of fluid distributions in 2D at the Darcy scale. X-ray methods present the highest resolution and flexibility for three-dimensional (3D) natural porous media characterization, and 3D characterization of fluid distributions in natural porous media. And MRI presents the best option for 3D characterization of fluid distribution, fluid flow, colloid transport, and reaction in artificial porous media. Obvious deficiencies ripe for method development are the ability to image transient processes such as fluid flow and colloid transport in natural porous media in three

  19. Functional brain imaging; Funktionelle Hirnbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Gizewski, E.R. [Medizinische Universitaet Innsbruck, Universitaetsklinik fuer Neuroradiologie, Innsbruck (Austria)

    2016-02-15

    Functional magnetic resonance imaging (fMRI) is a non-invasive method that has become one of the major tools for understanding human brain function and in recent years has also been developed for clinical applications. Changes in hemodynamic signals correspond to changes in neuronal activity with good spatial and temporal resolution in fMRI. Using high-field MR systems and increasingly dedicated statistics and postprocessing, activated brain areas can be detected and superimposed on anatomical images. Currently, fMRI data are often combined in multimodal imaging, e. g. with diffusion tensor imaging (DTI) sequences. This method is helping to further understand the physiology of cognitive brain processes and is also being used in a number of clinical applications. In addition to the blood oxygenation level-dependent (BOLD) signals, this article deals with the construction of fMRI investigations, selection of paradigms and evaluation in the clinical routine. Clinically, this method is mainly used in the planning of brain surgery, analyzing the location of brain tumors in relation to eloquent brain areas and the lateralization of language processing. As the BOLD signal is dependent on the strength of the magnetic field as well as other limitations, an overview of recent developments is given. Increases of magnetic field strength (7 T), available head coils and advances in MRI analytical methods have led to constant improvement in fMRI signals and experimental design. Especially the depiction of eloquent brain regions can be done easily and quickly and has become an essential part of presurgical planning. (orig.) [German] Mittlerweile ist die funktionelle MRT (fMRT) eine Methode, die nicht mehr nur in der neurowissenschaftlichen Routine verwendet wird. Die fMRT ermoeglicht die nichtinvasive Darstellung der Hirnaktivitaet in guter raeumlicher und zeitlicher Aufloesung unter Ausnutzung der Durchblutungsaenderung aufgrund der erhoehten Nervenzellaktivitaet. Unter

  20. 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.

  1. Non-Invasive Monitoring of Streptococcus pyogenes Vaccine Efficacy Using Biophotonic Imaging

    Science.gov (United States)

    Alam, Faraz M.; Bateman, Colin; Turner, Claire E.; Wiles, Siouxsie; Sriskandan, Shiranee

    2013-01-01

    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 105 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. PMID:24278474

  2. Non-Invasive Imaging of Neuroanatomical Structures and Neural Activation with High-Resolution MRI

    Science.gov (United States)

    Herberholz, Jens; Mishra, Subrata H.; Uma, Divya; Germann, Markus W.; Edwards, Donald H.; Potter, Kimberlee

    2011-01-01

    Several years ago, manganese-enhanced magnetic resonance imaging (MEMRI) was introduced as a new powerful tool to image active brain areas and to identify neural connections in living, non-human animals. Primarily restricted to studies in rodents and later adapted for bird species, MEMRI has recently been discovered as a useful technique for neuroimaging of invertebrate animals. Using crayfish as a model system, we highlight the advantages of MEMRI over conventional techniques for imaging of small nervous systems. MEMRI can be applied to image invertebrate nervous systems at relatively high spatial resolution, and permits identification of stimulus-evoked neural activation non-invasively. Since the selection of specific imaging parameters is critical for successful in vivo micro-imaging, we present an overview of different experimental conditions that are best suited for invertebrates. We also compare the effects of hardware and software specifications on image quality, and provide detailed descriptions of the steps necessary to prepare animals for successful imaging sessions. Careful consideration of hardware, software, experiments, and specimen preparation will promote a better understanding of this novel technique and facilitate future MEMRI studies in other laboratories. PMID:21503138

  3. 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.

  4. 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.

  5. Noninvasive measurement of internal jugular venous oxygen saturation by photoacoustic imaging

    Science.gov (United States)

    Garcia-Uribe, Alejandro; Erpelding, Todd N.; Ke, Haixin; Reddy, Kavya; Sharma, Anshuman; Wang, Lihong V.

    2014-03-01

    The metabolic rate and oxygen consumption of the brain is reflected in jugular venous oxygen saturation. In many clinical conditions, such as head trauma, stroke, and low cardiac output states, the brain is at risk for hypoxic-ischemic injury. The current gold standard for monitoring brain oxygenation is invasive and requires jugular vein catheterization under fluoroscopic guidance; and therefore it is rarely used. Photo-acoustic tomography in combination with ultrasound can be used to estimate oxygen saturation of the internal jugular vein in real-time. This noninvasive method will enable earlier detection and prevention of impending hypoxic brain injury. A wavelength-tunable dye laser pumped by a Nd:YAG laser delivers light through an optical fiber bundle, and a modified commercial ultrasound imaging system (Philips iU22) detects both the pulse-echo ultrasound (US) and photoacoustic (PA) signals. A custom-built multichannel data acquisition system renders co-registered ultrasound and photoacoustic images at 5 frames per second. After the jugular vein was localized in healthy volunteers, dualwavelength PA images were used to calculate the blood hemoglobin oxygen saturation from the internal jugular vein in vivo. The preliminary results raise confidence that this emerging technology can be used clinically as an accurate, noninvasive indicator of cerebral oxygenation.

  6. 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.

  7. Non-invasive current and voltage imaging techniques for integrated circuits using scanning probe microscopy

    Science.gov (United States)

    Campbell, A. N.; Cole, E. I., Jr.; Tangyunyong, Paiboon

    1995-06-01

    This report describes the first practical, non-invasive technique for detecting and imaging currents internal to operating integrated circuits (IC's). This technique is based on magnetic force microscopy and was developed under Sandia National Laboratories' LDRD (Laboratory Directed Research and Development) program during FY 93 and FY 94. LDRD funds were also used to explore a related technique, charge force microscopy, for voltage probing of IC's. This report describes the technical work performed under this LDRD as well as the outcomes of the project in terms of publications and awards, intellectual property and licensing, synergistic work, potential future work, hiring of additional permanent staff, and benefits to DOE's defense programs (DP).

  8. [Functional imaging of pain].

    Science.gov (United States)

    Peyron, Roland

    2014-01-01

    In this review, we summarize the contribution of functional imaging to the question of nociception in humans. In the beginning of the 90's, brain areas supposed to be involved in physiological pain processes essentially concerned the primary somatosensory area (SI), thalamus, and anterior cingulate cortex. In spite of these a priori hypotheses, the first imaging studies revealed that the main brain areas and those providing the most consistent activations in pain conditions were the insular and the SII cortices, bilaterally. This has been checked with other techniques such as intracerebral recordings of evoked potentials after nociceptive stimulations with laser showing a consistent response in the operculo-insular area whose amplitude correlates with pain intensity. In spite of electrode implantations in other areas of the brain, only rare and inconsistent responses have been found outside the operculo-insular cortices. With electrical stimulation delivered directly in the brain, it has also been shown that stimulation in this area only - and not in other brain areas - was able to elicit a painful sensation. Thus, over the last 15 years, the operculo-insular cortex has been re-discovered as a main area of pain integration, mainly in its sensory and intensity aspects. In neuropathic pain also, these areas have been demonstrated as being abnormally recruited, bilaterally, in response to innocuous stimuli. These results suggest that plastic changes may occur in brain areas that were pre-defined for generating pain sensations. Conversely, when the brain activations concomitant to pain relief were taken in account, a large number of studies pointed out medial prefrontal and rostral cingulate areas as being associated with pain controls. Interestingly, these activations may correlate with the magnitude of pain relief, with the activation of the peri-acqueductal grey (PAG) and, at least in some instances, with the involvement of endogenous opioids. © Société de

  9. Noninvasive radiographic assessment of cardiovascular function in acute and chronic respiratory failure

    International Nuclear Information System (INIS)

    Berger, H.J.; Matthay, R.A.

    1981-01-01

    Noninvasive radiographic techniques have provided a means of studying the natural history and pathogenesis of cardiovascular performance in acute and chronic respiratory failure. Chest radiography, radionuclide angiocardiography and thallium-201 imaging, and M mode and cross-sectional echocardiography have been employed. Each of these techniques has specific uses, attributes and limitations. For example, measurement of descending pulmonary arterial diameters on the plain chest radiograph allows determination of the presence or absence of pulmonary arterial hypertension. Right and left ventricular performance can be evaluated at rest and during exercise using radionuclide angiocardiography. The biventricular response to exercise and to therapeutic interventions also can be assessed with this approach. Evaluation of the pulmonary valve echogram and echocardiographic right ventricular dimensions have been shown to reflect right ventricular hemodynamics and size. Each of these noninvasive techniques has been applied to the study of patients with respiratory failure and has provided important physiologic data

  10. 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

  11. Exploring brain function with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Di Salle, F.; Formisano, E.; Linden, D.E.J.; Goebel, R.; Bonavita, S.; Pepino, A.; Smaltino, F.; Tedeschi, G.

    1999-01-01

    Since its invention in the early 1990s, functional magnetic resonance imaging (fMRI) has rapidly assumed a leading role among the techniques used to localize brain activity. The spatial and temporal resolution provided by state-of-the-art MR technology and its non-invasive character, which allows multiple studies of the same subject, are some of the main advantages of fMRI over the other functional neuroimaging modalities that are based on changes in blood flow and cortical metabolism. This paper describes the basic principles and methodology of fMRI and some aspects of its application to functional activation studies. Attention is focused on the physiology of the blood oxygenation level-dependent (BOLD) contrast mechanism and on the acquisition of functional time-series with echo planar imaging (EPI). We also provide an introduction to the current strategies for the correction of signal artefacts and other image processing techniques. In order to convey an idea of the numerous applications of fMRI, we will review some of the recent results in the fields of cognitive and sensorimotor psychology and physiology

  12. MR imaging of the heart: functional imaging

    International Nuclear Information System (INIS)

    Croisille, P.; Revel, D.

    2000-01-01

    To date, most applications of cardiovascular MRI relate to the evaluation of major vessels rather than the heart itself. However, MRI plays a major role in the evaluation of specific types of cardiovascular pathology, namely intracardiac and paracardiac masses, pericardial disease, and congenital heart disease. In addition, because the visualization of cardiovascular anatomy with MR is non-invasive and permits three-dimensional analysis but also allows functional assessment of the cardiac pump, it is clear that MRI will have a growing and significant impact over the next years. We review some of the technical aspect of cardiac MRI and describe the current and potential clinical and investigative applications of this new methodology. (orig.)

  13. 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.

  14. [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

  15. Non-invasive monitoring of in vivo hydrogel degradation and cartilage regeneration by multiparametric MR imaging

    Science.gov (United States)

    Chen, Zelong; Yan, Chenggong; Yan, Shina; Liu, Qin; Hou, Meirong; Xu, Yikai; Guo, Rui

    2018-01-01

    Numerous biodegradable hydrogels for cartilage regeneration have been widely used in the field of tissue engineering. However, to non-invasively monitor hydrogel degradation and efficiently evaluate cartilage restoration in situ is still challenging. Methods: A ultrasmall superparamagnetic iron oxide (USPIO)-labeled cellulose nanocrystal (CNC)/silk fibroin (SF)-blended hydrogel system was developed to monitor hydrogel degradation during cartilage regeneration. The physicochemical characterization and biocompatibility of the hydrogel were evaluated in vitro. The in vivo hydrogel degradation and cartilage regeneration of different implants were assessed using multiparametric magnetic resonance imaging (MRI) and further confirmed by histological analysis in a rabbit cartilage defect model for 3 months. Results: USPIO-labeled hydrogels showed sufficient MR contrast enhancement and retained stability without loss of the relaxation rate. Neither the mechanical properties of the hydrogels nor the proliferation of bone-marrow mesenchymal stem cells (BMSCs) were affected by USPIO labeling in vitro. CNC/SF hydrogels with BMSCs degraded more quickly than the acellular hydrogels as reflected by the MR relaxation rate trends in vivo. The morphology of neocartilage was noninvasively visualized by the three-dimensional water-selective cartilage MRI scan sequence, and the cartilage repair was further demonstrated by macroscopic and histological observations. Conclusion: This USPIO-labeled CNC/SF hydrogel system provides a new perspective on image-guided tissue engineering for cartilage regeneration. PMID:29464005

  16. Chronic pelvic pain: how does noninvasive imaging compare with diagnostic laparoscopy?

    Science.gov (United States)

    Tirlapur, Seema A; Daniels, Jane P; Khan, Khalid S

    2015-12-01

    Chronic pelvic pain (CPP) has an annual prevalence of 38/1000 in the UK, with coexisting pathologies often present. Diagnostic laparoscopy has long been the gold standard diagnostic test, but with up to 40% showing no abnormality, we explore the value of noninvasive imaging, such as pelvic ultrasound and MRI. A literature review from inception until January 2015 of the following databases: PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Excerpta Medica database, and System for Information on Grey Literature in Europe were performed to identify published studies assessing the usefulness of ultrasound, MRI, and laparoscopy in the diagnosis of CPP. Three studies (194 women) addressed their comparative performance in patients with endometriosis, showing the sensitivity of ultrasound ranged between 58 and 88.5%; MRI was 56-91.5% and in the one study using histology as its reference standard, the sensitivity of laparoscopy was 85.7%. Noninvasive imaging has the additional benefit of being well tolerated, safer, and cheaper than surgery. CPP, by nature of its multifactorial causation, can be difficult to manage and often requires a multidisciplinary team. Ultrasound and MRI may provide information about the presence or lack of abnormality, which would allow general practitioners or office gynaecologists to initiate treatment and think about surgery as a second-line investigative tool.

  17. Noninvasive quantitative measurement of colloid transport in mesoscale porous media using time lapse fluorescence imaging.

    Science.gov (United States)

    Bridge, Jonathan W; Banwart, Steven A; Heathwaite, A Louise

    2006-10-01

    We demonstrate noninvasive quantitative imaging of colloid and solute transport at millimeter to decimeter (meso-) scale. Ultraviolet (UV) excited fluorescent solute and colloid tracers were independently measured simultaneously during co-advection through saturated quartz sand. Pulse-input experiments were conducted at constant flow rates and ionic strengths 10(-3), 10(-2) and 10(-1) M NaCl. Tracers were 1.9 microm carboxylate latex microspheres and disodium fluorescein. Spatial moments analysis was used to quantify relative changes in mass distribution of the colloid and solute tracers over time. The solute advected through the sand at a constant velocity proportional to flow rate and was described well by a conservative transport model (CXTFIT). In unfavorable deposition conditions increasing ionic strength produced significant reduction in colloid center of mass transport velocity over time. Velocity trends correlated with the increasing fraction of colloid mass retained along the flowpath. Attachment efficiencies (defined by colloid filtration theory) calculated from nondestructive retained mass data were 0.013 +/- 0.03, 0.09 +/- 0.02, and 0.22 +/- 0.05 at 10(-3), 10(-2), and 10(-1) M ionic strength, respectively, which compared well with previously published data from breakthrough curves and destructive sampling. Mesoscale imaging of colloid mass dynamics can quantify key deposition and transport parameters based on noninvasive, nondestructive, spatially high-resolution data.

  18. Non-invasive brain stimulation to promote motor and functional recovery following spinal cord injury

    Directory of Open Access Journals (Sweden)

    Aysegul Gunduz

    2017-01-01

    Full Text Available We conducted a systematic review of studies using non-invasive brain stimulation (NIBS: repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS as a research and clinical tool aimed at improving motor and functional recovery or spasticity in patients following spinal cord injury (SCI under the assumption that if the residual corticospinal circuits could be stimulated appropriately, the changes might be accompanied by functional recovery or an improvement in spasticity. This review summarizes the literature on the changes induced by NIBS in the motor and functional recovery and spasticity control of the upper and lower extremities following SCI.

  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. A Minimum Spanning Forest Based Method for Noninvasive Cancer Detection with Hyperspectral Imaging

    Science.gov (United States)

    Pike, Robert; Lu, Guolan; Wang, Dongsheng; Chen, Zhuo Georgia; Fei, Baowei

    2016-01-01

    Goal The purpose of this paper is to develop a classification method that combines both spectral and spatial information for distinguishing cancer from healthy tissue on hyperspectral images in an animal model. Methods An automated algorithm based on a minimum spanning forest (MSF) and optimal band selection has been proposed to classify healthy and cancerous tissue on hyperspectral images. A support vector machine (SVM) classifier is trained to create a pixel-wise classification probability map of cancerous and healthy tissue. This map is then used to identify markers that are used to compute mutual information for a range of bands in the hyperspectral image and thus select the optimal bands. An MSF is finally grown to segment the image using spatial and spectral information. Conclusion The MSF based method with automatically selected bands proved to be accurate in determining the tumor boundary on hyperspectral images. Significance Hyperspectral imaging combined with the proposed classification technique has the potential to provide a noninvasive tool for cancer detection. PMID:26285052

  1. 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.

  2. Functional imaging of the pancreas

    International Nuclear Information System (INIS)

    Nakanishi, Fumiko

    1984-01-01

    An image processing technique for functional imaging of the pancreas was developed and is here reported. In this paper, clinical efficacy of the technique for detecting pancreatic abnormality is evaluated in comparison with conventional pancreatic scintigraphy and CT. For quantitative evaluation, functional rate, i.e. the rate of normal functioning pancreatic area, was calculated from the functional image and subtraction image. Two hundred and ninety-five cases were studied using this technique. Conventional image had a sensitivity of 65 % and a specificity of 78 %, while the use of functional imaging improved sensitivity to 88 % and specificity to 88 %. The mean functional rate in patients with pancreatic disease was significantly lower (33.3+-24.5 in patients with chronic pancreatitis, 28.1+-26.9 in patients with acute pancreatitis, 43.4+-22.3 in patients with diabetes mellitus, 20.4+-23.4 in patients with pancreatic cancer) than the mean functional rate in cases without pancreatic disease (86.4+-14.2). It is suggested that functional image of the pancreas reflecting pancreatic exocrine function and functional rate is a useful indicator of pancreatic exocrine function. (author)

  3. Noninvasive assessment of the iridial microcirculation in rats using sidestream dark field imaging.

    Science.gov (United States)

    Cerny, V; Zhou, J; Kelly, M; Alotibi, I; Turek, Z; Whynot, S; Saleh, I Abdo; Lehmann, C

    2013-02-01

    Sidestream dark field imaging represents a novel, noninvasive method to study the microcirculation in humans and animals. To-date, it has been used extensively in various peripheral tissues (e.g. sublingual area, intestinal mucosa), however no data for the ocular vasculature, including the iridial microcirculation, are currently available. Therefore, the aim of this study was to examine the reliability and reproducibility of sidestream dark field imaging within the iridial microcirculation in experimental animals. Male Lewis rats were anaesthetized and the iris microvasculature was observed using an sidestream dark field probe gently placed against a cover slip covering the right eye. All video sequences recorded were analysed off-line by using AVA 3.0 software (MicroVision Medical, Amsterdam, The Netherlands). Results are expressed as mean (±SE) or median (interquartile range). Clear images were recorded from each animal and the total number of analysable video sequences was 50. All raw data for selected vessel density parameters passed normality test. The total all and small vessel density (in mm mm(-2) ) were 22,6 (±0,58) and 19,6 (±0,68), respectively. The perfused all and small vessel density were 20,9 (±0,61) and 19,1 (±0,65), respectively. The mean values of all iris vessel density parameters are shown in Figure 4. The DeBacker Score (n/mm) was 15,2 (±0,45), the proportion of perfused vessel was 94,5% (89,8-99,1%), and the MFI was 3 points (3-3). Taken together, these results indicate that SDF imaging provides a reliable and noninvasive method to examine the iridial microvascular bed in vivo and, thus, may provide unique opportunities for the study of the iridial vascular network in various experimental and clinical settings and disease models. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  4. Noninvasive ultrasound molecular imaging of the effect of statins on endothelial inflammatory phenotype in early atherosclerosis.

    Directory of Open Access Journals (Sweden)

    Elham Khanicheh

    Full Text Available BACKGROUND/OBJECTIVES: Inflammatory changes on the endothelium are responsible for leukocyte recruitment to plaques in atherosclerosis. Noninvasive assessment of treatment-effects on endothelial inflammation may be of use for managing medical therapy and developing novel therapies. We hypothesized that molecular imaging of vascular cell adhesion molecule-1 (VCAM-1 with contrast enhanced ultrasound (CEU could assess treatment effects on endothelial phenotype in early atherosclerosis. METHODS: Mice with atherosclerosis produced by gene deletion of the LDL-receptor and Apobec-1-editing protein were studied. At 12 weeks of age, mice received 8 weeks of regular chow or atorvastatin-enriched chow (10 mg/kg/day. At 20 weeks, CEU molecular imaging for aortic endothelial VCAM-1 expression was performed with VCAM-1-targeted (MB(VCAM and control microbubbles (MB(Ctr. Aortic wall thickness was assessed with high frequency ultrasound. Histology, immunohistology and Western blot were used to assess plaque burden and VCAM-1 expression. RESULTS: Plaque burden was reduced on histology, and VCAM-1 was reduced on Western blot by atorvastatin, which corresponded to less endothelial expression of VCAM-1 on immunohistology. High frequency ultrasound did not detect differences in aortic wall thickness between groups. In contrast, CEU molecular imaging demonstrated selective signal enhancement for MB(VCAM in non-treated animals (MB(VCAM 2±0.3 vs MB(Ctr 0.7±0.2, p<0.01, but not in statin-treated animals (MB(VCAM 0.8±0.2 vs MB(Ctr 1.0±0.2, p = ns; p<0.01 for the effect of statin on MB(VCAM signal. CONCLUSIONS: Non-invasive CEU molecular imaging detects the effects of anti-inflammatory treatment on endothelial inflammation in early atherosclerosis. This easily accessible, low-cost technique may be useful in assessing treatment effects in preclinical research and in patients.

  5. 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.

  6. Brain imaging and brain function

    International Nuclear Information System (INIS)

    Sokoloff, L.

    1985-01-01

    This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage

  7. Detection of unruptured intracranial aneurysms on noninvasive imaging. Is there still a role for digital subtraction angiography?

    Science.gov (United States)

    Rustemi, Oriela; Alaraj, Ali; Shakur, Sophia F; Orning, Jennifer L; Du, Xinjian; Aletich, Victor A; Amin-Hanjani, Sepideh; Charbel, Fady T

    2015-01-01

    To determine the utility of digital subtraction angiography (DSA) in patients with unruptured intracranial aneurysms (UIA) detected on noninvasive imaging, such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA). The follow-up of patients with untreated UIAs involves serial imaging; however, this diagnosis may be based on false positive (FP) results. We examined the incidence of FPs in our institutional series. DSAs performed at our institution from January 2011 to June 2014 were retrospectively reviewed and patients referred with UIA detected on noninvasive imaging were selected. Clinical presentation as well as aneurysm location, size, and number reported on DSA and noninvasive imaging were assessed. Two hundred and eighty six patients (mean age 56.8 years, female 74.8%) with a total of 355 UIA were included. Thirty-one patients had a symptomatic presentation. Analysis per patient showed the pooled FP rate of noninvasive imaging was 15%. MRA FP was 13% (22/171) and CTA FP was 18% (22/120). FP increased significantly with aneurysm size < 3.5 mm on MRA (P < 0.001) and <4.0 mm on CTA (P = 0.01). Mean aneurysm size among symptomatic patients was significantly larger (P < 0.001) as compared to the incidental group (17.8 vs. 7.7 mm). No location was significantly susceptible to false detection of aneurysms. DSA detection of FP UIA diagnosed on noninvasive imaging is significantly higher for aneurysms <4.0 mm. Accurate diagnosis with DSA may eliminate the need for further follow-up and its associated negative psychological and economic effects. Within the limitations of this retrospective study, we conclude that DSA has a diagnostic role in small aneurysms detected on noninvasive imaging.

  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. 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. Assessment of a noninvasive optical photoplethysmography imaging device with dynamic tissue phantom models.

    Science.gov (United States)

    Nwafor, C Ikenna; Plant, Kevin D; King, Darlene R; McCall, Brian P; Squiers, John J; Fan, Wensheng; DiMaio, J Michael; Thatcher, Jeffrey E

    2017-09-01

    Noncontact photoplethysmography (PPG) has been studied as a method to provide low-cost, noninvasive, two-dimensional blood oxygenation measurements and medical imaging for a variety of near-surface pathologies. To evaluate this technology in a laboratory setting, dynamic tissue phantoms were developed with tunable parameters that mimic physiologic properties of the skin, including blood vessel volume change, pulse wave frequency, and tissue scattering and absorption. Tissue phantoms were generated using an elastic tubing to represent a blood vessel where the luminal volume could be modulated with a pulsatile fluid flow. The blood was mimicked with a scattering and absorbing motility standard, and the tissue with a gelatin-lipid emulsion hydrogel. A noncontact PPG imaging system was then evaluated using the phantoms. Noncontact PPG imaging accurately identified pulse frequency, and PPG signals from these phantoms suggest that the phantoms can be used to evaluate noncontact PPG imaging systems. Such information may be valuable to the development of future PPG imaging systems. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  11. Optical imaging of fast, dynamic neurophysiological function.

    Energy Technology Data Exchange (ETDEWEB)

    Rector, D. M. (David M.); Carter, K. M. (Kathleen M.); Yao, X. (Xincheng); George, J. S. (John S.)

    2002-01-01

    Fast evoked responses were imaged from rat dorsal medulla and whisker barrel cortex. To investigate the biophysical mechanisms involved, fast optical responses associated with isolated crustacean nerve stimulation were recorded using birefringence and scattered light. Such studies allow optimization of non-invasive imaging techniques being developed for use in humans.

  12. Development of an X-ray Computed Tomography System for Non-Invasive Imaging of Industrial Materials

    International Nuclear Information System (INIS)

    Abdullah, J.; Sipaun, S. M.; Mustapha, I.; Zain, R. M.; Rahman, M. F. A.; Mustapha, M.; Shaari, M. R.; Hassan, H.; Said, M. K. M.; Mohamad, G. H. P.; Ibrahim, M. M.

    2008-01-01

    X-ray computed tomography is a powerful non-invasive imaging technique for viewing an object's inner structures in two-dimensional cross-section images without the need to physically section it. The invention of CT techniques revolutionised the field of medical diagnostic imaging because it provided more detailed and useful information than any previous non-invasive imaging techniques. The method is increasingly being used in industry, aerospace, geosciences and archaeology. This paper describes the development of an X-ray computed tomography system for imaging of industrial materials. The theoretical aspects of CT scanner, the system configurations and the adopted algorithm for image reconstruction are discussed. The penetrating rays from a 160 kV industrial X-ray machine were used to investigate structures that manifest in a manufactured component or product. Some results were presented in this paper

  13. Is there a gender difference in noninvasive coronary imaging? Multislice computed tomography for noninvasive detection of coronary stenoses

    Directory of Open Access Journals (Sweden)

    Hamm Bernd

    2008-01-01

    Full Text Available Abstract Background Multislice computed tomography (MSCT coronary angiography is the foremost alternative to invasive coronary angiography. Methods We sought to compare the diagnostic accuracy of MSCT in female and male patients with suspected coronary disease. Altogether 50 women and 95 men underwent MSCT with 0.5 mm detector collimation. Coronary artery stenoses of at least 50% on conventional coronary angiography were considered significant. Results The coronary vessel diameters of all four main coronary artery branches were significantly larger in men than in women. The diagnostic accuracy of MSCT in identifying patients with coronary artery disease was significantly lower for women (72% compared with men (89%, p p p Conclusion Noninvasive coronary angiography with MSCT might be less accurate and sensitive for women than men. Also, women are exposed to a significantly higher effective radiation dose than men.

  14. 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. Copyright © 2012 Wiley Periodicals, Inc.

  15. 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.

  16. Novel Noninvasive Brain Disease Detection System Using a Facial Image Sensor

    Science.gov (United States)

    Shu, Ting; Zhang, Bob; Tang, Yuan Yan

    2017-01-01

    Brain disease including any conditions or disabilities that affect the brain is fast becoming a leading cause of death. The traditional diagnostic methods of brain disease are time-consuming, inconvenient and non-patient friendly. As more and more individuals undergo examinations to determine if they suffer from any form of brain disease, developing noninvasive, efficient, and patient friendly detection systems will be beneficial. Therefore, in this paper, we propose a novel noninvasive brain disease detection system based on the analysis of facial colors. The system consists of four components. A facial image is first captured through a specialized sensor, where four facial key blocks are next located automatically from the various facial regions. Color features are extracted from each block to form a feature vector for classification via the Probabilistic Collaborative based Classifier. To thoroughly test the system and its performance, seven facial key block combinations were experimented. The best result was achieved using the second facial key block, where it showed that the Probabilistic Collaborative based Classifier is the most suitable. The overall performance of the proposed system achieves an accuracy −95%, a sensitivity −94.33%, a specificity −95.67%, and an average processing time (for one sample) of <1 min at brain disease detection. PMID:29292716

  17. Novel Noninvasive Brain Disease Detection System Using a Facial Image Sensor

    Directory of Open Access Journals (Sweden)

    Ting Shu

    2017-12-01

    Full Text Available Brain disease including any conditions or disabilities that affect the brain is fast becoming a leading cause of death. The traditional diagnostic methods of brain disease are time-consuming, inconvenient and non-patient friendly. As more and more individuals undergo examinations to determine if they suffer from any form of brain disease, developing noninvasive, efficient, and patient friendly detection systems will be beneficial. Therefore, in this paper, we propose a novel noninvasive brain disease detection system based on the analysis of facial colors. The system consists of four components. A facial image is first captured through a specialized sensor, where four facial key blocks are next located automatically from the various facial regions. Color features are extracted from each block to form a feature vector for classification via the Probabilistic Collaborative based Classifier. To thoroughly test the system and its performance, seven facial key block combinations were experimented. The best result was achieved using the second facial key block, where it showed that the Probabilistic Collaborative based Classifier is the most suitable. The overall performance of the proposed system achieves an accuracy −95%, a sensitivity −94.33%, a specificity −95.67%, and an average processing time (for one sample of <1 min at brain disease detection.

  18. Novel Noninvasive Brain Disease Detection System Using a Facial Image Sensor.

    Science.gov (United States)

    Shu, Ting; Zhang, Bob; Tang, Yuan Yan

    2017-12-08

    Brain disease including any conditions or disabilities that affect the brain is fast becoming a leading cause of death. The traditional diagnostic methods of brain disease are time-consuming, inconvenient and non-patient friendly. As more and more individuals undergo examinations to determine if they suffer from any form of brain disease, developing noninvasive, efficient, and patient friendly detection systems will be beneficial. Therefore, in this paper, we propose a novel noninvasive brain disease detection system based on the analysis of facial colors. The system consists of four components. A facial image is first captured through a specialized sensor, where four facial key blocks are next located automatically from the various facial regions. Color features are extracted from each block to form a feature vector for classification via the Probabilistic Collaborative based Classifier. To thoroughly test the system and its performance, seven facial key block combinations were experimented. The best result was achieved using the second facial key block, where it showed that the Probabilistic Collaborative based Classifier is the most suitable. The overall performance of the proposed system achieves an accuracy -95%, a sensitivity -94.33%, a specificity -95.67%, and an average processing time (for one sample) of detection.

  19. 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.

  20. Noninvasive assessment of coronary collaterals in man by PET perfusion imaging

    International Nuclear Information System (INIS)

    Demer, L.L.; Gould, K.L.; Goldstein, R.A.; Kirkeeide, R.L.

    1990-01-01

    At present, coronary collateralization cannot be identified or assessed noninvasively in patients. In animal studies, coronary collaterals are associated with coronary steal, defined as a regional fall in perfusion during coronary arteriolar vasodilation. To determine the effect of coronary arteriolar vasodilation on collateral bed perfusion in man, myocardial perfusion imaging was performed before and after pharmacologic coronary vasodilation in patients with coronary artery disease (CAD). Regional myocardial activity of 82 Rb or 13 N ammonia was measured by positron emission tomography (PET) at rest and with intravenous dipyridamole/handgrip stress in 28 patients with angiographic collaterals and in 25 control patients with similar CAD severity by quantitative arteriography. Regional myocardial activity decreased after dipyridamole, indicating coronary steal, in 25 of 28 patients with angiographic collaterals and in only 4 of 25 control patients without angiographic collaterals. These findings suggest that developed collaterals are associated with myocardial steal in patients with CAD, allowing potential use of PET for non-invasive identification of coronary collateralization

  1. Non-invasive mechanical properties estimation of embedded objects using tactile imaging sensor

    Science.gov (United States)

    Saleheen, Firdous; Oleksyuk, Vira; Sahu, Amrita; Won, Chang-Hee

    2013-05-01

    Non-invasive mechanical property estimation of an embedded object (tumor) can be used in medicine for characterization between malignant and benign lesions. We developed a tactile imaging sensor which is capable of detecting mechanical properties of inclusions. Studies show that stiffness of tumor is a key physiological discerning parameter for malignancy. As our sensor compresses the tumor from the surface, the sensing probe deforms, and the light scatters. This forms the tactile image. Using the features of the image, we can estimate the mechanical properties such as size, depth, and elasticity of the embedded object. To test the performance of the method, a phantom study was performed. Silicone rubber balls were used as embedded objects inside the tissue mimicking substrate made of Polydimethylsiloxane. The average relative errors for size, depth, and elasticity were found to be 67.5%, 48.2%, and 69.1%, respectively. To test the feasibility of the sensor in estimating the elasticity of tumor, a pilot clinical study was performed on twenty breast cancer patients. The estimated elasticity was correlated with the biopsy results. Preliminary results show that the sensitivity of 67% and the specificity of 91.7% for elasticity. Results from the clinical study suggest that the tactile imaging sensor may be used as a tumor malignancy characterization tool.

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

    International Nuclear Information System (INIS)

    Dubois, J.; Perrin, M.; Mangin, J.F.; Cointepas, Y.; Duchesnay, E.; Le Bihan, D.; Hertz-Pannier, L.; Dehaene-Lambertz, G.; Dubois, J.; Dehaene-Lambertz, G.; Perrin, M.; Mangin, J.F.; Cointepas, Y.; Duchesnay, E.; Le Bihan, D.; Hertz-Pannier, L.

    2008-01-01

    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)

  3. 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)

  4. Noninvasive assessment of vascular function and hydraulic power and efficiency in pediatric Fontan patients.

    Science.gov (United States)

    Myers, Kimberley A; Leung, Mande T; Terri Potts, M; Potts, James E; Sandor, George G S

    2013-10-01

    Invasive studies have shown that children with Fontan palliation have abnormal arterial stiffness, impedance, and hydraulic power and efficiency. The aim of this study was to assess these indexes noninvasively in a cohort of children with Fontan circulation using Doppler echocardiography and compare their results with those of healthy peers. This was a case-control study of 22 Fontan patients and 31 healthy control children. Using standard two-dimensional, M-mode, and Doppler echocardiographic imaging and carotid artery applanation tonometry, aortic flows, dimensions, and pulse-wave velocity were measured, and vascular impedance and arterial stiffness were calculated. Hydraulic power and efficiency were calculated from standard fluid dynamics formulae. The median age was similar between groups. Stroke volume index (39 vs 39 mL/min/m(2)) and cardiac index (2.6 vs 2.5 L/min/m(2)) were similar. Aortic cross-sectional area (3.3 vs 2.8 cm(2)), peak aortic flow (302 vs 261 cm(3)/sec), and myocardial performance index (0.47 vs 0.25) were higher and ejection fraction (50% vs 66%) was lower in Fontan patients. Input impedance (61 vs 83 dyne · sec/cm(5)/m(2)) was lower in Fontan patients. Pulse-wave velocity (488 vs 364 cm/sec), elastic pressure-strain modulus (305 vs 263 torr), and stiffness index (4.15 vs 3.04) were higher in Fontan patients. Total arterial compliance (1.29 vs 1.32 mL/torr/m(2)) and mean power (606 vs 527 mW/m(2)) were similar and total hydraulic power (716 vs 627 mW/m(2)) was higher in Fontan patients. Efficiency and the power cost per unit of forward flow were similar. Despite stiffer aortas, Fontan patients generate more hydraulic power associated with decreased ventricular function to achieve a similar hydraulic efficiency. In Fontan patients, therapy that is given to improve ventricular function may need to target vascular stiffness as well. This technique may be used to monitor the efficacy of therapeutic interventions. Copyright © 2013 American

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

    Science.gov (United States)

    Kjørstad, Åsmund; Corteville, Dominique M R; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

    2015-12-01

    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. 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. Copyright © 2015. Published by Elsevier GmbH.

  6. 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.

  7. A field test study of our non-invasive thermal image analyzer for deceptive detection

    Science.gov (United States)

    Sumriddetchkajorn, Sarun; Somboonkaew, Armote; Sodsong, Tawee; Promduang, Itthipol; Sumriddetchkajorn, Niti

    2007-07-01

    We have developed a non-invasive thermal image analyzer for deceptive detection (TAD2) where the far-infrared data around the periorbital and nostril areas are simultaneously analyzed. Measured change in maximum skin temperature around two periorbital regions is converted to a relative blood flow velocity. A respiration pattern is also simultaneously determined via the ratio of the measured maximum and minimum temperatures in the nostril area. In addition, our TAD2 employs a simple normalized cross correlation scheme to independently track locations of the two periorbital and nostril areas. Our field case study from 7 subjects in two real crime scenes and with the use of our baseline classification criteria shows two-fold improvement in classification rate compared to our analysis using either the periorbital or nostril area alone.

  8. Noninvasive hemodynamic assessment, treatment outcome prediction and follow-up of aortic coarctation from MR imaging.

    Science.gov (United States)

    Ralovich, Kristóf; Itu, Lucian; Vitanovski, Dime; Sharma, Puneet; Ionasec, Razvan; Mihalef, Viorel; Krawtschuk, Waldemar; Zheng, Yefeng; Everett, Allen; Pongiglione, Giacomo; Leonardi, Benedetta; Ringel, Richard; Navab, Nassir; Heimann, Tobias; Comaniciu, Dorin

    2015-05-01

    Coarctation of the aorta (CoA) is a congenital heart disease characterized by an abnormal narrowing of the proximal descending aorta. Severity of this pathology is quantified by the blood pressure drop (△P) across the stenotic coarctation lesion. In order to evaluate the physiological significance of the preoperative coarctation and to assess the postoperative results, the hemodynamic analysis is routinely performed by measuring the △P across the coarctation site via invasive cardiac catheterization. The focus of this work is to present an alternative, noninvasive measurement of blood pressure drop △P through the introduction of a fast, image-based workflow for personalized computational modeling of the CoA hemodynamics. The authors propose an end-to-end system comprised of shape and computational models, their personalization setup using MR imaging, and a fast, noninvasive method based on computational fluid dynamics (CFD) to estimate the pre- and postoperative hemodynamics for coarctation patients. A virtual treatment method is investigated to assess the predictive power of our approach. Automatic thoracic aorta segmentation was applied on a population of 212 3D MR volumes, with mean symmetric point-to-mesh error of 3.00 ± 1.58 mm and average computation time of 8 s. Through quantitative evaluation of 6 CoA patients, good agreement between computed blood pressure drop and catheter measurements is shown: average differences are 2.38 ± 0.82 mm Hg (pre-), 1.10 ± 0.63 mm Hg (postoperative), and 4.99 ± 3.00 mm Hg (virtual stenting), respectively. The complete workflow is realized in a fast, mostly-automated system that is integrable in the clinical setting. To the best of our knowledge, this is the first time that three different settings (preoperative--severity assessment, poststenting--follow-up, and virtual stenting--treatment outcome prediction) of CoA are investigated on multiple subjects. We believe that in future-given wider clinical validation

  9. Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans.

    Science.gov (United States)

    Trenado, Carlos; Elben, Saskia; Petri, David; Hirschmann, Jan; Groiss, Stefan J; Vesper, Jan; Schnitzler, Alfons; Wojtecki, Lars

    2016-05-19

    In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging (fMRI) for extracting crucial information about the mechanism of the human brain, such methods remain insufficient to provide information about physiological processes reflecting cognitive and emotional functions at the subcortical level. In this respect, modern invasive clinical approaches in humans, such as deep brain stimulation (DBS), offer a tremendous possibility to record subcortical brain activity, namely local field potentials (LFPs) representing coherent activity of neural assemblies from localized basal ganglia or thalamic regions. Notwithstanding the fact that invasive approaches in humans are applied only after medical indication and thus recorded data correspond to altered brain circuits, valuable insight can be gained regarding the presence of intact brain functions in relation to brain oscillatory activity and the pathophysiology of disorders in response to experimental cognitive paradigms. In this direction, a growing number of DBS studies in patients with Parkinson's disease (PD) target not only motor functions but also higher level processes such as emotions, decision-making, attention, memory and sensory perception. Recent clinical trials also emphasize the role of DBS as an alternative treatment in neuropsychiatric disorders ranging from obsessive compulsive disorder (OCD) to chronic disorders of consciousness (DOC). Consequently, we focus on the use of combined invasive (LFP) and non-invasive (EEG) human brain recordings in assessing the role of cortical-subcortical structures in cognitive and emotional processing trough experimental paradigms (e.g. speech stimuli with emotional connotation or paradigms of cognitive control such as the Flanker task), for patients undergoing DBS treatment.

  10. New technology of functional infrared imaging and its clinical applications

    Science.gov (United States)

    Yang, Hongqin; Xie, Shusen; Lu, Zukang; Liu, Zhongqi

    2006-01-01

    With improvements in infrared camera technology, the promise of reduced costs and noninvasive character, infrared thermal imaging resurges in medicine. The paper introduces a new technology of functional infrared imaging, thermal texture maps (TTM), which is not only an apparatus for thermal radiation imaging but also a new method for revealing the relationship between the temperature distribution of the skin surface and the emission field inside body. The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Any disease in the body is associated with an alteration of the thermal distribution of human body. Infrared thermography is noninvasive, so it is the best choice for studying the physiology of thermoregulation and the thermal dysfunction associated with diseases. Reading and extracting information from the thermograms is a complex and subjective task that can be greatly facilitated by computerized techniques. Through image processing and measurement technology, surface or internal radiation sources can be non-invasively distinguished through extrapolation. We discuss the principle, the evaluation procedure and the effectiveness of TTM technology in the clinical detection and diagnosis of cancers, especially in their early stages and other diseases by comparing with other imaging technologies, such as ultrasound. Several study cases are given to show the effectiveness of this method. At last, we point out the applications of TTM technology in the research field of traditional medicine.

  11. Non-invasive brain-to-brain interface (BBI: establishing functional links between two brains.

    Directory of Open Access Journals (Sweden)

    Seung-Schik Yoo

    Full Text Available Transcranial focused ultrasound (FUS is capable of modulating the neural activity of specific brain regions, with a potential role as a non-invasive computer-to-brain interface (CBI. In conjunction with the use of brain-to-computer interface (BCI techniques that translate brain function to generate computer commands, we investigated the feasibility of using the FUS-based CBI to non-invasively establish a functional link between the brains of different species (i.e. human and Sprague-Dawley rat, thus creating a brain-to-brain interface (BBI. The implementation was aimed to non-invasively translate the human volunteer's intention to stimulate a rat's brain motor area that is responsible for the tail movement. The volunteer initiated the intention by looking at a strobe light flicker on a computer display, and the degree of synchronization in the electroencephalographic steady-state-visual-evoked-potentials (SSVEP with respect to the strobe frequency was analyzed using a computer. Increased signal amplitude in the SSVEP, indicating the volunteer's intention, triggered the delivery of a burst-mode FUS (350 kHz ultrasound frequency, tone burst duration of 0.5 ms, pulse repetition frequency of 1 kHz, given for 300 msec duration to excite the motor area of an anesthetized rat transcranially. The successful excitation subsequently elicited the tail movement, which was detected by a motion sensor. The interface was achieved at 94.0±3.0% accuracy, with a time delay of 1.59±1.07 sec from the thought-initiation to the creation of the tail movement. Our results demonstrate the feasibility of a computer-mediated BBI that links central neural functions between two biological entities, which may confer unexplored opportunities in the study of neuroscience with potential implications for therapeutic applications.

  12. CARDIAC TRANSPLANT REJECTION AND NON-INVASIVE COMON CAROTID ARTERY WALL FUNCTIONAL INDICES

    Directory of Open Access Journals (Sweden)

    A. O. Shevchenko

    2015-01-01

    Full Text Available Allograft rejection would entail an increase in certain blood biomarkers and active substances derived from activated inflammatory cells which could influence entire vascular endothelial function and deteriorate arterial wall stiffness. We propose that carotid wall functional indices measured with non-invasive ultrasound could we valuable markers of the subclinical cardiac allograft rejection. Aim. Our goal was to analyze the clinical utility of functional common carotid wall (CCW variables measured with high-resolution Doppler ultrasound as a non-invasive screening tool for allograft rejection in cardiac transplant patients (pts. Methods. One hundred and seventy one pts included 93 cardiac recipients, 30 dilated cardiomyopathy waiting list pts, and 48 stable coronary artery disease (SCAD pts without decompensated heart failure were included. Along with resistive index (Ri, pulsative index (Pi, and CCW intima-media thickness (IMT, CCW rigidity index (iRIG was estimated using empirical equation. Non-invasive evaluation was performed in cardiac transplant recipients prior the endomyo- cardial biopsy. Results. Neither of Ri, Pi, or CCW IMT were different in studied subgroups. iRIG was signifi- cantly lower in SCAD pts when compared to the dilated cardiomyopathy subgroup. The later had similar values with cardiac transplant recipients without rejection. Antibody-mediated and cellular rejection were found in 22 (23.7% and 17 (18.3% cardiac recipients, respectively. Mean iRIG in pts without rejection was significantly lower in comparison to antibody-mediated rejection and cell-mediated (5514.7 ± 2404.0 vs 11856.1 ± 6643.5 and 16071.9 ± 10029.1 cm/sec2, respectively, p = 0.001. Area under ROC for iRIG was 0.90 ± 0.03 units2. Analysis showed that iRIG values above estimated treshold 7172 cm/sec2 suggested relative risk of any type of rejection 17.7 (95%CI = 6.3–49.9 sensitivity 80.5%, specificity – 81.1%, negative predictive value – 84

  13. Magnetic resonance imaging goes postmortem: noninvasive detection and assessment of myocardial infarction by postmortem MRI

    International Nuclear Information System (INIS)

    Jackowski, Christian; Warntjes, Marcel J.B.; Persson, Anders; Berge, Johan; Baer, Walter

    2011-01-01

    To investigate the performance of postmortem magnetic resonance imaging (pmMRI) in identification and characterization of lethal myocardial infarction in a non-invasive manner on human corpses. Before forensic autopsy, 20 human forensic corpses were examined on a 1.5-T system for the presence of myocardial infarction. Short axis, transversal and longitudinal long axis images (T1-weighted; T2-weighted; PD-weighted) were acquired in situ. In subsequent autopsy, the section technique was adapted to short axis images. Histological investigations were conducted to confirm autopsy and/or radiological diagnoses. Nineteen myocardial lesions were detected and age staged with pmMRI, of which 13 were histologically confirmed (chronic, subacute and acute). Six lesions interpreted as peracute by pmMRI showed no macroscopic or histological finding. Five of the six peracute lesions correlated well to coronary pathology, and one case displayed a severe hypertrophic alteration. pmMRI reliably demonstrates chronic, subacute and acute myocardial infarction in situ. In peracute cases pmMRI may display ischemic lesions undetectable at autopsy and routine histology. pmMRI has the potential to substantiate autopsy and to counteract the loss of reliable information on causes of death due to the recent disappearance of the clinical autopsy. (orig.)

  14. CT and image processing non-invasive indicators of sickle cell secondary pulmonary hypertension.

    Science.gov (United States)

    Linguraru, Marius George; Orandi, Babak J; Van Uitert, Robert L; Mukherjee, Nisha; Summers, Ronald M; Gladwin, Mark T; Machado, Roberto F; Wood, Bradford J

    2008-01-01

    This retrospective study investigates the potential of image analysis to quantify for the presence and extent of pulmonary hypertension secondary to sickle cell disease (SCD). A combination of fast marching and geodesic active contours level sets were employed to segment the pulmonary artery from smoothed CT-Angiography images from 16 SCD patients and 16 matching controls. An algorithm based on fast marching methods was used to compute the centerline of the segmented arteries to measure automatically the diameters of the pulmonary trunk and first branches of the pulmonary arteries. Results show that the pulmonary trunk and arterial branches are significantly larger in diameter in SCD patients as compared to controls (p-values of 0.002 for trunk and 0.0003 for branches). For validation, the results were compared with manually measured values and did not demonstrate significant difference (mean p-values 0.71). CT with image processing shows great potential as a surrogate indicator of pulmonary hemodynamics or response to therapy, which could be an important tool for drug discovery and noninvasive clinical surveillance.

  15. 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

  16. Value of magnetic resonance imaging for the noninvasive detection of stenosis in coronary artery bypass grafts and recipient coronary arteries

    NARCIS (Netherlands)

    Langerak, Susan E.; Vliegen, Hubert W.; Jukema, J. Wouter; Kunz, Patrik; Zwinderman, Aeilko H.; Lamb, Hildo J.; van der Wall, Ernst E.; de Roos, Albert

    2003-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) is a potential noninvasive diagnostic tool to detect coronary artery bypass graft stenosis, but its value in clinical practice remains to be established. We investigated the value of MRI in detecting stenotic grafts, including recipient vessels. METHODS

  17. En-face optical coherence tomography - a novel application of non-invasive imaging to art conservation.

    Science.gov (United States)

    Liang, Haida; Cid, Marta; Cucu, R; Dobre, G; Podoleanu, A; Pedro, Justin; Saunders, David

    2005-08-08

    Optical Coherence Tomography (OCT) is an optical interferometric technique developed mainly for in vivo imaging of the eye and biological tissues. In this paper, we demonstrate the potential of OCT for non-invasive examination of museum paintings. Two en-face scanning OCT systems operating at 850 nm and 1300 nm were used to produce B-scan and C-scan images at typical working distances of 2 cm. The 3D images produced by the OCT systems show not only the structure of the varnish layer but also the paint layers and underdrawings (preparatory drawings under the paint layers). The highest ever resolution and dynamic range images of underdrawings are presented and for the first time it is possible to find out non-invasively on which layer the underdrawings were drawn.

  18. Functional imaging in Huntington disease.

    Science.gov (United States)

    Niethammer, Martin; Eidelberg, David

    2017-01-01

    Functional imaging has been increasingly used in the study of neurodegenerative diseases as such techniques can elucidate neurochemical and functional changes that cannot be captured with structural imaging. Unlike other neurodegenerative diseases, in Huntington disease (HD) genetic testing allows for diagnostic certainty. Thus, the focus has been on understanding the pathophysiogic processes underlying the development of the disease, as well as the identification of potential biomarkers to monitor disease progression, particularly during the presymptomatic stage. These imaging methods have expanded our understanding of HD beyond dopaminergic deficits and striatal cell loss, and have described alteration in widespread networks relating to motor and cognitive symptoms. In this chapter, we review the current literature on radiotracer and functional magnetic resonance imaging relating to HD. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 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.

  20. Proceedings of Joint International Symposium on the role of noninvasive imaging modalities in clinical decision making of coronary artery disease

    International Nuclear Information System (INIS)

    Mena, I.G.; Strauss, H.W.

    1986-01-01

    This report contains ten papers on the use of noninvasive imaging in clinical diagnosis and decision making. Topics include a cost analysis of magnetic resonance imaging in medical technology, diagnostic uses of MRI in chronic coronary artery disease, clinical applications of cine computed tomography, the use of PET as a clinical tool, and the use of echocardiography in coronary artery disease. Individual papers are processed separately for the data base

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

    Science.gov (United States)

    Hynynen, Kullervo; Jones, Ryan M.

    2016-01-01

    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. PMID:27494561

  2. Insights into atherosclerosis from invasive and non-invasive imaging studies: Should we treat subclinical atherosclerosis?

    Science.gov (United States)

    Santos, Raul D; Nasir, Khurram

    2009-08-01

    Although atherosclerosis is associated with the elderly, young adults with hypercholesterolemia and other cardiovascular risk factors may have subclinical atherosclerotic disease. In many cases, when two or more risk factors are present, conventional risk assessment using the Framingham score, that was not designed to detect atherosclerotic plaques, may significantly underestimate the extent of atherosclerosis. Several non-invasive imaging technologies now make it possible to identify subclinical atherosclerosis before symptoms appear or major vascular events occur. These include B-mode ultrasound to measure carotid intima-media thickness, computed tomography to measure coronary artery calcification, and high-resolution magnetic resonance imaging to evaluate plaque size and composition. On the basis of available evidence, assessment of subclinical atherosclerosis should be considered in persons judged to be at intermediate risk by Framingham score, because test results may influence risk stratification and, consequently, the intensity of therapeutic intervention. Patients with significant subclinical atherosclerosis are at high risk and, like other high-risk individuals, should receive treatment designed to achieve aggressive low-density lipoprotein cholesterol targets. Clinical studies show that statin therapy may delay atherosclerosis progression and that intensive therapy with rosuvastatin may actually reverse the atherosclerotic process.

  3. 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.

  4. Noninvasive molecular imaging of hypoxia in human xenografts: comparing hypoxia-induced gene expression with endogenous and exogenous hypoxia markers.

    Science.gov (United States)

    He, Fuqiu; Deng, Xuelong; Wen, Bixiu; Liu, Yueping; Sun, Xiaorong; Xing, Ligang; Minami, Akiko; Huang, Yunhong; Chen, Qing; Zanzonico, Pat B; Ling, C Clifton; Li, Gloria C

    2008-10-15

    Tumor hypoxia is important in the development and treatment of human cancers. We have developed a novel xenograft model for studying and imaging of hypoxia-induced gene expression. A hypoxia-inducible dual reporter herpes simplex virus type 1 thymidine kinase and enhanced green fluorescence protein (HSV1-TKeGFP), under the control of hypoxia response element (9HRE), was stably transfected into human colorectal HT29 cancer cells. Selected clones were further enriched by repeated live cell sorting gated for hypoxia-induced eGFP expression. Fluorescent microscopy, fluorescence-activated cell sorting, and radioactive substrate trapping assays showed strong hypoxia-induced expression of eGFP and HSV1-tk enzyme in the HT29-9HRE cells in vitro. Sequential micropositron emission tomography (PET) imaging of tumor-bearing animals, using the hypoxic cell tracer (18)F-FMISO and the reporter substrate (124)I-FIAU, yielded similar tumor hypoxia images for the HT29-9HRE xenograft but not in the parental HT29 tumor. Using autoradiography and IHC, detailed spatial distributions in tumor sections were obtained and compared for the following hypoxia-associated biomarkers in the HT29-9HRE xenograft: (124)I-FIAU, (18)F-FMISO, Hoechst (perfusion), lectin-TRITC (functional blood vessels), eGFP, pimonidazole, EF5, and CA9. Intratumoral distributions of (124)I-FIAU and (18)F-FMISO were similar, and eGFP, pimonidazole, EF5, and CA9 colocalized in the same areas but not in well-perfused regions that were positive for Hoechst and lectin-TRITC. In enabling the detection of hypoxia-induced molecular events and mapping their distribution in vivo with serial noninvasive positron emission tomography imaging, and multiple variable analysis with immunohistochemistry and fluorescence microscopy, this human xenograft model provides a valuable tool for studying tumor hypoxia and in validating existing and future exogenous markers for tumor hypoxia.

  5. Utility and reliability of non-invasive muscle function tests in high-fat-fed mice.

    Science.gov (United States)

    Martinez-Huenchullan, Sergio F; McLennan, Susan V; Ban, Linda A; Morsch, Marco; Twigg, Stephen M; Tam, Charmaine S

    2017-07-01

    What is the central question of this study? Non-invasive muscle function tests have not been validated for use in the study of muscle performance in high-fat-fed mice. What is the main finding and its importance? This study shows that grip strength, hang wire and four-limb hanging tests are able to discriminate the muscle performance between chow-fed and high-fat-fed mice at different time points, with grip strength being reliable after 5, 10 and 20 weeks of dietary intervention. Non-invasive tests are commonly used for assessing muscle function in animal models. The value of these tests in obesity, a condition where muscle strength is reduced, is unclear. We investigated the utility of three non-invasive muscle function tests, namely grip strength (GS), hang wire (HW) and four-limb hanging (FLH), in C57BL/6 mice fed chow (chow group, n = 48) or a high-fat diet (HFD group, n = 48) for 20 weeks. Muscle function tests were performed at 5, 10 and 20 weeks. After 10 and 20 weeks, HFD mice had significantly reduced GS (in newtons; mean ± SD: 10 weeks chow, 1.89 ± 0.1 and HFD, 1.79 ± 0.1; 20 weeks chow, 1.99 ± 0.1 and HFD, 1.75 ± 0.1), FLH [in seconds per gram body weight; median (interquartile range): 10 weeks chow, 2552 (1337-4964) and HFD, 1230 (749-1994); 20 weeks chow, 2048 (765-3864) and HFD, 1036 (717-1855)] and HW reaches [n; median (interquartile range): 10 weeks chow, 4 (2-5) and HFD, 2 (1-3); 20 weeks chow, 3 (1-5) and HFD, 1 (0-2)] and higher falls [n; median (interquartile range): 10 weeks chow, 0 (0-2) and HFD, 3 (1-7); 20 weeks chow, 1 (0-4) and HFD, 8 (5-10)]. Grip strength was reliable in both dietary groups [intraclass correlation coefficient (ICC) = 0.5-0.8; P tests are valuable and reliable tools for assessment of muscle strength and function in high-fat-fed mice. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

  6. 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.

  7. Zwitterionic near infrared fluorescent agents for noninvasive real-time transcutaneous assessment of kidney function.

    Science.gov (United States)

    Huang, Jiaguo; Weinfurter, Stefanie; Daniele, Cristina; Perciaccante, Rossana; Federica, Rodeghiero; Della Ciana, Leopoldo; Pill, Johannes; Gretz, Norbert

    2017-04-01

    We developed novel zwitterionic near infrared (NIR) fluorescent agents (ABZWCY-HPβCD and AAZWCY-HPβCD), which exhibit favorable hydrophilicity, low plasma protein binding, high stability and non-toxicity. These attractive characteristics ensure that they are excreted rapidly, without any skin accumulation or metabolism in vivo . More importantly, zwitterionic HPβCD based agents can be efficiently filtrated by the glomerulus and completely excreted through the kidneys into urine without reabsorption or secretion in the kidney proximal tubule. Relying on these novel zwitterionic NIR agents and a transcutaneous device, we demonstrate a rapid, robust and biocompatible approach for assessing kidney function in rat models of both healthy rats and those with kidney disease, without the need for time-consuming blood/urine sample preparation. Our work provides a promising tool for in vivo real-time non-invasive kidney function assessment in preclinical applications.

  8. Technetium-99m labeled antisense oligonucleotide-noninvasive tumor imaging in mice

    International Nuclear Information System (INIS)

    Qin, G.M.; Zhang, Y.X.; An, R.; Gao, Z.R.; Cao, W.; Cao, G.X.; Hnatowich, D.J.

    2002-01-01

    Single-stranded RNA and DNA oligonucleotides may be useful as radiopharmaceuticals for antisense and other in vivo applications if convenient methods for stably attaching radionuclides such as 99m Tc can be developed. The c-myc oncogene works in cooperation with other oncogenes in a variety of malignant tumors. The concentration of c-myc messenger RNA increases rapidly 30 to 50 fold during DNA synthesis, thus making it a suitable target for following the progression of malignancy by noninvasive imaging with radiolabeled antisense oligonucleotide probes. Methods: 1 Oligonucleotide Conjugation: A solution of single stranded amine-derivatized DNA (100-1000μg) was prepared at a concentration of 2 mg/ml in 0.25M sodium bicarbonate, 1 M sodium chloride, 1mM EDTA, pH8.5. 2 Oligonucleotide Labeling: A fresh 50mg/ml solution of sodium tartrate was prepared in sterile 0.5 M ammonium The ability of the labeled DNA to hybridize to its complement was analyzed by Sep-Pak column chromatography before and after the addition of the complementary DNA. 3 Biodistribution and Tumor Imaging Studies: A colony of KM mice (15-20g) were inoculated with 1x10 6 Ehrlich carcinoma tumor cells in the right thigh, and the tumors were allowed to grow for 6-7 days to a size of 1.0-1.5 cm in diameter. Biodistribution studies were performed in 32 KM mice after 50 μCi per mouse of 99m Tc-labeled oncogene probes were injected intravenously. A total of 8 mice were injected intravenously in the tail vein with 1-2 mCi of 99m Tc-labeled sense or antisense probes, immobilized with ketamine hydrochloride and imaged periodically from 0.5hr to 24hr with a gamma camera. Results: Essentially complete conjugation was achieved by reverse-phase Sep-Pak C18 chromatography analysis. The labeled antisense DNA still remained the ability to hybridize with its complementary DNA. The highest accumulation of label was in the liver first, with the kidney and small bowel next. The injected activity localized in the lesion

  9. 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

  10. Non-invasive assessment of right ventricular function at rest and on exercise in obstructive airways disease

    International Nuclear Information System (INIS)

    Tweddel, A.; Martin, W.; McGhie, I.; Neilly, B.; Stevenson, R.; Hutton, I.

    1985-01-01

    Non-invasive assessment of right ventricular function is of clinical interest in the patient with obstructive airways disease. Gated Xenon 133 scanning allows right ventricular function to be evaluated in isolation from the left ventricle, and with rapid clearance from the lungs, scans may be repeated within 5 minutes. 400mBq of Xenon 133 were injected intravenously over 20 seconds and images were obtained using a mobile gamma camera. Maximal symptom limited exercise was performed on a supine bicycle ergometer. The normal range for right ventricular ejection fraction (RVEF) was obtained from 10 volunteers - 40-55% at rest rising by 5-15% during exercise. In 10 patients with acute obstructive airways disease, all had reduced RVEF 21 +- 3%. In chronic obstructive airways disease, if resting RVEF was greater than 30%, ejection fraction increased on exercise. If resting ejection fraction was abnormal than RVEF was reduced or unchanged on exercise (mean 15 +- 9%), and this was associated with dilatation of both the right ventricle and atrium. In conclusion, gated Xenon 133 offers a simple method of assessing right ventricular function at rest and on exercise in the patient with obstructive airways disease

  11. Noninvasive investigation of exocrine pancreatic function: Feasibility of cine dynamic MRCP with a spatially selective inversion-recovery pulse.

    Science.gov (United States)

    Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

    2015-11-01

    To investigate the feasibility of noncontrast-enhanced cine dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatially selective inversion-recovery (IR) pulse for evaluating exocrine pancreatic function in comparison with the N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) test as a pancreatic exocrine function test. Twenty subjects with or without chronic pancreatitis were included. MRCP with a spatially selective IR pulse was repeated every 15 seconds for 5 minutes to acquire a total of 20 images (cine-dynamic MRCP). The median and mean frequency of the observation (the number of times) and the moving distance (mean secretion grading scores) of pancreatic juice inflow on cine-dynamic MRCP were compared with a BT-PABA test. The urinary PABA excretion rate (%) had significant positive correlations with both the mean secretion grade (r = 0.66, P = 0.002) and frequency of secretory inflow (r = 0.62, P = 0.004) in cine dynamic MRCP. Both the mean frequency of observations of pancreatic secretory inflow (1.4 ± 1.6 times vs. 14.3 ± 4.2 times, P Cine dynamic MRCP with a spatially selective IR pulse may have potential for estimating the pancreatic exocrine function noninvasively as a substitute for the BT-PABA test. © 2015 Wiley Periodicals, Inc.

  12. Non-invasive measurements of granular flows by magnetic resonance imaging. Technical progress report for the quarter ending December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, M.; Altobelli, S.A.; Caprihan, A.; Fukushima, E.; Jeong, E.K.

    1993-01-20

    Magnetic Resonance Imaging (MRI) was used to measure granular-flow in a partially filled, steadily rotating, long, horizontal cylinder. This non-invasive technique can yield statistically averaged two-dimensional concentrations and velocity profiles anywhere in the flow of suitable granular materials. First, rigid body motion of a cylinder fill with granular material was studied to confirm the validity of this method. Then, the density variation of the flowing layer where particles collide and dilate, and the depth of the flowing layer and the flow velocity profile were obtained as a function of the cylinder rotation rate.

  13. Structural and functional imaging for vascular targeted photodynamic therapy

    Science.gov (United States)

    Li, Buhong; Gu, Ying; Wilson, Brian C.

    2017-02-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely used for the prevention or treatment of vascular-related diseases, such as localized prostate cancer, wet age-related macular degeneration, port wine stains, esophageal varices and bleeding gastrointestinal mucosal lesions. In this study, the fundamental mechanisms of vascular responses during and after V-PDT will be introduced. Based on the V-PDT treatment of blood vessels in dorsal skinfold window chamber model, the structural and functional imaging, which including white light microscopy, laser speckle imaging, singlet oxygen luminescence imaging, and fluorescence imaging for evaluating vascular damage will be presented, respectively. The results indicate that vessel constriction and blood flow dynamics could be considered as the crucial biomarkers for quantitative evaluation of vascular damage. In addition, future perspectives of non-invasive optical imaging for evaluating vascular damage of V-PDT will be discussed.

  14. Signal and image processing techniques for functional near-infrared imaging of the human brain

    Science.gov (United States)

    Toronov, Vladislav Y.; Zhang, Xiaofeng; Fabiani, Monica; Gratton, Gabriele; Webb, Andrew G.

    2011-01-01

    Near-infrared spectro-imaging (NIRSI) is a quickly developing method for the in-vivo imaging of biological tissues. In particular, it is now extensively employed for imaging the human brain. In this non-invasive technique, the information about the brain is obtained from the analysis of spatial light bundles formed by the photons traveling from light sources to detectors placed on the surface of the head. Most significant problems in the functional brain NIRSI are the separation of the brain information from the physiological noise in non-cerebral tissues, and the localization of functional signals. In this paper we describe signal and image processing techniques we developed in order to measure two types of functional cerebral signals: the hemodynamic responses, and neuronal responses. PMID:21738383

  15. Challenges of functional imaging research of pain in children

    Directory of Open Access Journals (Sweden)

    Sava Simona

    2009-06-01

    Full Text Available Abstract Functional imaging has revolutionized the neurosciences. In the pain field it has dramatically altered our understanding of how the brain undergoes significant functional, anatomical and chemical changes in patients with chronic pain. However, most studies have been performed in adults. Because functional imaging is non-invasive and can be performed in awake individuals, applications in children have become more prevalent, but only recently in the pain field. Measures of changes in the brains of children have important implications in understanding neural plasticity in response to acute and chronic pain in the developing brain. Such findings may have implications for treatments in children affected by chronic pain and provide novel insights into chronic pain syndromes in adults. In this review we summarize this potential and discuss specific concerns related to the imaging of pain in children.

  16. 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.

  17. IDH mutation status is associated with a distinct hypoxia/angiogenesis transcriptome signature which is non-invasively predictable with rCBV imaging in human glioma.

    Science.gov (United States)

    Kickingereder, Philipp; Sahm, Felix; Radbruch, Alexander; Wick, Wolfgang; Heiland, Sabine; Deimling, Andreas von; Bendszus, Martin; Wiestler, Benedikt

    2015-11-05

    The recent identification of IDH mutations in gliomas and several other cancers suggests that this pathway is involved in oncogenesis; however effector functions are complex and yet incompletely understood. To study the regulatory effects of IDH on hypoxia-inducible-factor 1-alpha (HIF1A), a driving force in hypoxia-initiated angiogenesis, we analyzed mRNA expression profiles of 288 glioma patients and show decreased expression of HIF1A targets on a single-gene and pathway level, strong inhibition of upstream regulators such as HIF1A and downstream biological functions such as angio- and vasculogenesis in IDH mutant tumors. Genotype/imaging phenotype correlation analysis with relative cerebral blood volume (rCBV) MRI - a robust and non-invasive estimate of tumor angiogenesis - in 73 treatment-naive patients with low-grade and anaplastic gliomas showed that a one-unit increase in rCBV corresponded to a two-third decrease in the odds for an IDH mutation and correctly predicted IDH mutation status in 88% of patients. Together, these findings (1) show that IDH mutation status is associated with a distinct angiogenesis transcriptome signature which is non-invasively predictable with rCBV imaging and (2) highlight the potential future of radiogenomics (i.e. the correlation between cancer imaging and genomic features) towards a more accurate diagnostic workup of brain tumors.

  18. Reorganizing the intrinsic functional architecture of the human primary motor cortex during rest with non-invasive cortical stimulation.

    Directory of Open Access Journals (Sweden)

    Rafael Polanía

    Full Text Available The primary motor cortex (M1 is the main effector structure implicated in the generation of voluntary movements and is directly involved in motor learning. The intrinsic horizontal neuronal connections of M1 exhibit short-term and long-term plasticity, which is a strong substrate for learning-related map reorganization. Transcranial direct current stimulation (tDCS applied for few minutes over M1 has been shown to induce relatively long-lasting plastic alterations and to modulate motor performance. Here we test the hypothesis that the relatively long-lasting synaptic modification induced by tDCS over M1 results in the alteration of associations among populations of M1 neurons which may be reflected in changes of its functional architecture. fMRI resting-state datasets were acquired immediately before and after 10 minutes of tDCS during rest, with the anode/cathode placed over the left M1. For each functional dataset, grey-matter voxels belonging to Brodmann area 4 (BA4 were labelled and afterwards BA4 voxel-based synchronization matrices were calculated and thresholded to construct undirected graphs. Nodal network parameters which characterize the architecture of functional networks (connectivity degree, clustering coefficient and characteristic path-length were computed, transformed to volume maps and compared before and after stimulation. At the dorsolateral-BA4 region cathodal tDCS boosted local connectedness, while anodal-tDCS enhanced long distance functional communication within M1. Additionally, the more efficient the functional architecture of M1 was at baseline, the more efficient the tDCS-induced functional modulations were. In summary, we show here that it is possible to non-invasively reorganize the intrinsic functional architecture of M1, and to image such alterations.

  19. Use of the ODD-luciferase transgene for the non-invasive imaging of spontaneous tumors in mice.

    Directory of Open Access Journals (Sweden)

    Scott J Goldman

    2011-03-01

    Full Text Available In humans, imaging of tumors provides rapid, accurate assessment of tumor growth and location. In laboratory animals, however, the imaging of spontaneously occurring tumors continues to pose many technical and logistical problems. Recently a mouse model was generated in which a chimeric protein consisting of HIF-1α oxygen-dependent degradation domain (ODD fused to luciferase was ubiquitously expressed in all tissues. Hypoxic stress leads to the accumulation of ODD-luciferase in the tissues of this mouse model which can be identified by non-invasive bioluminescence measurement. Since solid tumors often contain hypoxic regions, we performed proof-of-principle experiments testing whether this transgenic mouse model may be used as a universal platform for non-invasive imaging analysis of spontaneous solid tumors.ODD-luciferase transgenic mice were bred with MMTV-neu/beclin1+/- mice. Upon injection of luciferin, bioluminescent background of normal tissues in the transgenic mice and bioluminescent signals from spontaneously mammary carcinomas were measured non-invasively with an IVIS Spectrum imaging station. Tumor volumes were measured manually and the histology of tumor tissues was analyzed.Our results show that spontaneous mammary tumors in ODD-luciferase transgenic mice generate substantial bioluminescent signals, which are clearly discernable from background tissue luminescence. Moreover, we demonstrate a strong quantitative correlation between the bioluminescent tumor contour and the volume of palpable tumors. We further demonstrate that shrinkage of the volume of spontaneous tumors in response to chemotherapeutic treatment can be determined quantitatively using this system. Finally, we show that the growth and development of spontaneous tumors can be monitored longitudinally over several weeks. Thus, our results suggest that this model could potentially provide a practical, reliable, and cost-effective non-invasive quantitative method for

  20. Repeated sessions of noninvasive brain DC stimulation is associated with motor function improvement in stroke patients.

    Science.gov (United States)

    Boggio, Paulo S; Nunes, Alice; Rigonatti, Sergio P; Nitsche, Michael A; Pascual-Leone, Alvaro; Fregni, Felipe

    2007-01-01

    Recent evidence has suggested that a simple technique of noninvasive brain stimulation - transcranial direct current stimulation (tDCS) - is associated with a significant motor function improvement in stroke patients. We tested the motor performance improvement in stroke patients following 4 weekly sessions of sham, anodal- and cathodal tDCS (experiment 1) and the effects of 5 consecutive daily sessions of cathodal tDCS (experiment 2). A blinded rater evaluated motor function using the Jebsen-Taylor Hand Function Test. There was a significant main effect of stimulation condition (p=0.009) in experiment 1. Furthermore there was a significant motor function improvement after either cathodal tDCS of the unaffected hemisphere (p=0.016) or anodal tDCS of the affected hemisphere (p=0.046) when compared to sham tDCS. There was no cumulative effect associated with weekly sessions of tDCS, however consecutive daily sessions of tDCS (experiment 2) were associated with a significant effect on time (pmotor function improvement in stroke patients; and support that consecutive daily sessions of tDCS might increase its behavioral effects. Because the technique of tDCS is simple, safe and non-expensive; our findings support further research on the use of this technique for the rehabilitation of patients with stroke.

  1. Mapping metabolic changes by noninvasive, multiparametric, high-resolution imaging using endogenous contrast.

    Science.gov (United States)

    Liu, Zhiyi; Pouli, Dimitra; Alonzo, Carlo A; Varone, Antonio; Karaliota, Sevasti; Quinn, Kyle P; Münger, Karl; Karalis, Katia P; Georgakoudi, Irene

    2018-03-01

    Monitoring subcellular functional and structural changes associated with metabolism is essential for understanding healthy tissue development and the progression of numerous diseases, including cancer, diabetes, and cardiovascular and neurodegenerative disorders. Unfortunately, established methods for this purpose either are destructive or require the use of exogenous agents. Recent work has highlighted the potential of endogenous two-photon excited fluorescence (TPEF) as a method to monitor subtle metabolic changes; however, mechanistic understanding of the connections between the detected optical signal and the underlying metabolic pathways has been lacking. We present a quantitative approach to detecting both functional and structural metabolic biomarkers noninvasively, relying on endogenous TPEF from two coenzymes, NADH (reduced form of nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide). We perform multiparametric analysis of three optical biomarkers within intact, living cells and three-dimensional tissues: cellular redox state, NADH fluorescence lifetime, and mitochondrial clustering. We monitor the biomarkers in cells and tissues subjected to metabolic perturbations that trigger changes in distinct metabolic processes, including glycolysis and glutaminolysis, extrinsic and intrinsic mitochondrial uncoupling, and fatty acid oxidation and synthesis. We demonstrate that these optical biomarkers provide complementary insights into the underlying biological mechanisms. Thus, when used in combination, these biomarkers can serve as a valuable tool for sensitive, label-free identification of changes in specific metabolic pathways and characterization of the heterogeneity of the elicited responses with single-cell resolution.

  2. Functional magnetic resonance imaging of higher brain activity

    International Nuclear Information System (INIS)

    Cui He; Wang Yunjiu; Chen Runsheng; Tang Xiaowei.

    1996-01-01

    Functional magnetic resonance images (fMRIs) exhibit small differences in the magnetic resonance signal intensity in positions corresponding to focal areas of brain activation. These signal are caused by variation in the oxygenation state of the venous vasculature. Using this non-invasive and dynamic method, it is possible to localize functional brain activation, in vivo, in normal individuals, with an accuracy of millimeters and a temporal resolution of seconds. Though a series of technical difficulties remain, fMRI is increasingly becoming a key method for visualizing the working brain, and uncovering the topographical organization of the human brain, and understanding the relationship between brain and the mind

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

    Science.gov (United States)

    2012-01-01

    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. PMID:23241497

  4. 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.

  5. 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

    2013-01-01

    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 co-incubated 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 co-administration of DiD (donor) nanoparticles and DiR (acceptor) nanoparticles. In contrast, another group of nude mice i.v. administrated with DiD/DiR co-loaded 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 nano-formulations for lipophilic drug delivery. PMID:24033270

  6. Noninvasive diagnosis of coronary arterial lesions by exercise thallium-201 myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Kawai, Naoki; Okada, Mitsuhiro; Miyakoda, Hiroyuki

    1983-01-01

    The value of exercise thallium-201 myocardial perfusion imaging (Ex MPI) for identifying diseased coronary arteries was evaluated in 57 effort angina patients without previous myocardial infarction. The territory of the individual major coronary artery on myocardial images was determined by analysis of the site of perfusion defects in 29 patients with single vessel or isolated left main disease. The anteroseptal wall was considered as the territory of the left anterior descending artery (LAD). The inferior and the posterolateral walls were assumed to be supplied by the right coronary (RCA) and the left circumflex (LCX) arteries, respectively. Ex MPI was sensitive for identifying the diseased artery in single vessel disease, the sensitivity being 86% for LAD, 66% for LCX and 71% for RCA. However, the sensitivity tended to decrease as the number of diseased vessels increased. An improved sensitivity was observed by analysis of the regional myocardial washout rate of thallium-201 in patients with triple vessel disease, in which the criterion of Tl-201 perfusion defect was not sensitive. Ex MPI was highly specific for individual coronary artery disease. Several factors supposed to affect the sensitivity of Ex MPI for detection of individual lesions were analysed. The sensitivity increased, in general, with the severity of stenosis and it was lower for a less severely diseased artery in multiple vessel disease. The presence or absence of coronary collaterals seemed not to affect the sensitivity of Ex MPI. In conclusion, Ex MPI was considered to be a useful noninvasive technique to detect the diseased coronary arteries in patients with single vessel disease or the most severely diseased artery in patients with multiple vessel disease

  7. 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, pcurrent gold-standard method, i.e., DXA, while additional information are obtained by the QUS for predicting fracture risk by monitoring of bone's quality. The developed QUS imaging technique can be used to assess bone's quantity and quality with improved accuracy and precision.

  8. Functional morphology underlies performance differences among invasive and non-invasive ruderal Rubus species.

    Science.gov (United States)

    Caplan, Joshua S; Yeakley, J Alan

    2013-10-01

    The ability of some introduced plant species to outperform native species under altered resource conditions makes them highly productive in ecosystems with surplus resources. However, ruderal native species are also productive when resources are available. The differences in abundance among invasive and non-invasive ruderal plants may be related to differences in ability to maintain access to or store resources for continual use. For a group of ruderal species in the Pacific Northwest of North America (invasive Rubus armeniacus; non-invasive R. ursinus, R. parviflorus, R. spectabilis, and Rosa nutkana), we sought to determine whether differences in functional morphological traits, especially metrics of water access and storage, were consistent with differences in water conductance and growth rate. We also investigated the changes in these traits in response to abundant vs. limited water availability. Rubus armeniacus had among the largest root systems and cane cross-sectional areas, the lowest cane tissue densities, and the most plastic ratios of leaf area to plant mass and of xylem area to leaf area, often sharing its rank with R. ursinus or Rosa nutkana. These three species had the highest water conductance and relative growth rates, though Rubus armeniacus grew the most rapidly when water was not limited. Our results suggest that water access and storage abilities vary with morphology among the ruderal species investigated, and that these abilities, in combination, are greatest in the invasive. In turn, functional morphological traits allow R. armeniacus to maintain rapid gas exchange rates during the dry summers in its invaded range, conferring on it high productivity.

  9. Treatment Response Assessment in IDH-Mutant Glioma Patients by Noninvasive 3D Functional Spectroscopic Mapping of 2-Hydroxyglutarate.

    Science.gov (United States)

    Andronesi, Ovidiu C; Loebel, Franziska; Bogner, Wolfgang; Marjańska, Małgorzata; Vander Heiden, Matthew G; Iafrate, A John; Dietrich, Jorg; Batchelor, Tracy T; Gerstner, Elizabeth R; Kaelin, William G; Chi, Andrew S; Rosen, Bruce R; Cahill, Daniel P

    2016-04-01

    Measurements of objective response rates are critical to evaluate new glioma therapies. The hallmark metabolic alteration in gliomas with mutant isocitrate dehydrogenase (IDH) is the overproduction of oncometabolite 2-hydroxyglutarate (2HG), which plays a key role in malignant transformation. 2HG represents an ideal biomarker to probe treatment response in IDH-mutant glioma patients, and we hypothesized a decrease in 2HG levels would be measureable by in vivo magnetic resonance spectroscopy (MRS) as a result of antitumor therapy. We report a prospective longitudinal imaging study performed in 25 IDH-mutant glioma patients receiving adjuvant radiation and chemotherapy. A newly developed 3D MRS imaging was used to noninvasively image 2HG. Paired Student t test was used to compare pre- and posttreatment tumor 2HG values. Test-retest measurements were performed to determine the threshold for 2HG functional spectroscopic maps (fSM). Univariate and multivariate regression were performed to correlate 2HG changes with Karnofsky performance score (KPS). We found that mean 2HG (2HG/Cre) levels decreased significantly (median = 48.1%; 95% confidence interval = 27.3%-56.5%;P= 0.007) in the posttreatment scan. The volume of decreased 2HG correlates (R(2)= 0.88,P= 0.002) with clinical status evaluated by KPS. We demonstrate that dynamic measurements of 2HG are feasible by 3D fSM, and the decrease of 2HG levels can monitor treatment response in patients with IDH-mutant gliomas. Our results indicate that quantitative in vivo 2HG imaging may be used for precision medicine and early response assessment in clinical trials of therapies targeting IDH-mutant gliomas. ©2015 American Association for Cancer Research.

  10. Noninvasive detection of hepatic lipidosis in dairy cows with calibrated ultrasonographic image analysis.

    Science.gov (United States)

    Starke, A; Haudum, A; Weijers, G; Herzog, K; Wohlsein, P; Beyerbach, M; de Korte, C L; Thijssen, J M; Rehage, J

    2010-07-01

    =100mg of TAG/g of FW), and 0.97 (or=100mg of TAG/g of FW). The CAUS methodology and software for digitally analyzing liver ultrasonographic images is considered feasible for noninvasive screening of fatty liver in dairy herd health programs. Using the single parameter linear regression equation might be ideal for practical applications. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Simple and non-invasive techniques to evaluate the function of CircuLite Synergy.

    Science.gov (United States)

    Mohite, Prashant N; Bowles, Christopher T; Sabashnikov, Anton; Popov, Aron-Frederik; Patil, Nikhil P; Sáez, Diana García; Banner, Nicholas R; Simon, André R

    2014-11-01

    The Synergy CircuLite micropump is a novel partial-support miniature left ventricular assist device that propels 2-3 l/min blood from the left atrium into the right subclavian artery. The ability of currently available investigative modalities to confirm Synergy pump malfunction is limited. The Synergy speed fluctuates periodically (at 10-s intervals) from the baseline to a transient decrease followed by a transient increase (alternating speed algorithm, ASA) with the purpose of changing the blood flow behaviour, thereby reducing thrombogenicity. The aim of this study was to develop a simple non-invasive monitoring technique to assess pump function based on the detection of the ASA in the peripheral microcirculation. Between February 2012 and July 2013, 10 patients with advanced chronic heart failure underwent Synergy implantation at our institution. The pump function was assessed by echocardiography and invasive monitoring according to standard protocols; additionally, the pump speed and power consumption were monitored. During the pump function assessment, the pulse oximeter waveform was recorded from the index fingers of the left and right hand with simultaneous pump auscultation using a stethoscope positioned on the pump (right infra-clavicular pocket). The pulse oximeter waveform was readily detectable from the right and left hand of all study patients. If the Synergy function was normal, there was a significant difference in the morphology of the pulse oximeter waveform from each hand: the ASA algorithm produced a more pronounced variation (giant wave) in the trace from the right hand than from the left. The giant waves invariably coincided with the sound variation associated with the ASA algorithms, which were detected regularly at 10-s intervals. We describe a simple, readily applicable, inexpensive, non-invasive technique that allows evaluation of Synergy pump function and may have diagnostic utility under conditions of suspected pump thrombus

  12. Non-invasive assessment of choledocholithiasis in patients with gallstones and abnormal liver function.

    Science.gov (United States)

    Al-Jiffry, Bilal O; Elfateh, Abdeen; Chundrigar, Tariq; Othman, Bassem; Almalki, Owaid; Rayza, Fares; Niyaz, Hashem; Elmakhzangy, Hesham; Hatem, Mohammed

    2013-09-21

    To find a non-invasive strategy for detecting choledocholithiasis before cholecystectomy, with an acceptable negative rate of endoscopic retrograde cholangiopancreatography. All patients with symptomatic gallstones were included in the study. Patients with abnormal liver functions and common bile duct abnormalities on ultrasound were referred for endoscopic retrograde cholangiopancreatography. Patients with normal ultrasound were referred to magnetic resonance cholangiopancreatography. All those who had a negative magnetic resonance or endoscopic retrograde cholangiopancreatography underwent laparoscopic cholecystectomy with intraoperative cholangiography. Seventy-eight point five percent of patients had laparoscopic cholecystectomy directly with no further investigations. Twenty-one point five percent had abnormal liver function tests, of which 52.8% had normal ultrasound results. This strategy avoided unnecessary magnetic resonance cholangiopancreatography in 47.2% of patients with abnormal liver function tests with a negative endoscopic retrograde cholangiopancreatography rate of 10%. It also avoided un-necessary endoscopic retrograde cholangiopancreatography in 35.2% of patients with abnormal liver function. This strategy reduces the cost of the routine use of magnetic resonance cholangiopancreatography, in the diagnosis and treatment of common bile duct stones before laparoscopic cholecystectomy.

  13. Value of Cardiovascular Magnetic Resonance Imaging in Noninvasive Risk Stratification in Tetralogy of Fallot

    NARCIS (Netherlands)

    Bokma, Jouke P.; de Wilde, Koen C.; Vliegen, Hubert W.; van Dijk, Arie P.; van Melle, Joost P.; Meijboom, Folkert J.; Zwinderman, Aeilko H.; Groenink, Maarten; Mulder, Barbara J. M.; Bouma, Berto J.

    IMPORTANCE Adults late after total correction of tetralogy of Fallot (TOF) are at risk for majorcomplications. Cardiovascular magnetic resonance (CMR) imaging is recommended toquantify right ventricular (RV) and left ventricular (LV) function. However, a commonly usedrisk model by Khairy et al

  14. Changing Utilization of Noninvasive Diagnostic Imaging Over 2 Decades: An Examination Family-Focused Analysis of Medicare Claims Using the Neiman Imaging Types of Service Categorization System.

    Science.gov (United States)

    Rosman, David A; Duszak, Richard; Wang, Wenyi; Hughes, Danny R; Rosenkrantz, Andrew B

    2018-02-01

    The objective of our study was to use a new modality and body region categorization system to assess changing utilization of noninvasive diagnostic imaging in the Medicare fee-for-service population over a recent 20-year period (1994-2013). All Medicare Part B Physician Fee Schedule services billed between 1994 and 2013 were identified using Physician/Supplier Procedure Summary master files. Billed codes for diagnostic imaging were classified using the Neiman Imaging Types of Service (NITOS) coding system by both modality and body region. Utilization rates per 1000 beneficiaries were calculated for families of services. Among all diagnostic imaging modalities, growth was greatest for MRI (+312%) and CT (+151%) and was lower for ultrasound, nuclear medicine, and radiography and fluoroscopy (range, +1% to +31%). Among body regions, service growth was greatest for brain (+126%) and spine (+74%) imaging; showed milder growth (range, +18% to +67%) for imaging of the head and neck, breast, abdomen and pelvis, and extremity; and showed slight declines (range, -2% to -7%) for cardiac and chest imaging overall. The following specific imaging service families showed massive (> +100%) growth: cardiac CT, cardiac MRI, and breast MRI. NITOS categorization permits identification of temporal shifts in noninvasive diagnostic imaging by specific modality- and region-focused families, providing a granular understanding and reproducible analysis of global changes in imaging overall. Service family-level perspectives may help inform ongoing policy efforts to optimize imaging utilization and appropriateness.

  15. (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......-d-glucoheptulose and 1,3-dideoxy-1,3-difluoro-d-glucoheptulose) µmol per 3×10(6)cells. (19)F MRI experiments also allowed the detection of 1-deoxy-1-fluoro-d-mannoheptulose in rat hepatocytes. All three (19)F-mannoheptuloses cited above, as well as 7-deoxy-7-fluoro-d-mannoheptulose and 1-deoxy-1-fluoro......-mannoheptulose in inhibiting insulin release. The 1-deoxy-1-fluoro-d-mannoheptulose and 3-deoxy-3-fluoro-d-mannoheptulose only marginally affected INS-1 cell viability. These findings are compatible with the view that selected (19)F-heptuloses may represent suitable tools for the non-invasive imaging of hepatocytes...

  16. Combination of optoacoustics and ultrasound imaging for non-invasive, rapid assessment, and management of circulatory shock

    Science.gov (United States)

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

    2011-03-01

    We developed a noninvasive, optoacoustic diagnostic platform for monitoring of multiple physiologic variables in inpatients and outpatients. One of the most important applications of this platform is noninvasive, rapid assessment and management of circulatory shock, a common condition in critically ill patients. At present, monitoring of circulatory shock requires measurement of central venous blood oxygenation using invasive procedures such as insertion of catheters in central veins. Hemoglobin saturation below 70% in central veins indicates circulatory shock that requires immediate treatment. We built a portable optoacoustic system for noninvasive measurement of central venous oxygenation. In this study we used the optoacoustic system and clinical ultrasound imaging systems for rapid optoacoustic probing of these veins. The optoacoustic system utilizes a custom-made, sensitive optoacoustic probe that was developed in our laboratory for monitoring of blood oxygenation in deep blood vessels. The studies were performed in human subjects with different geometry (depth, size) of the veins. The ultrasound imaging systems permitted rapid identification of specific blood vessels for optoacoustic probing. We developed a novel algorithm for continuous, realtime, and precise measurement of blood oxygenation in blood vessels. Precision of central venous oxygenation measurement obtained in the study was very high: 1%. Our results indicate that the combination of optoacoustics and ultrasound imaging systems can provide more rapid and accurate assessment and management of the circulatory shock.

  17. Medicare payments for noninvasive diagnostic imaging are now higher to nonradiologist physicians than to radiologists.

    Science.gov (United States)

    Levin, David C; Rao, Vijay M; Parker, Laurence; Frangos, Andrea J; Sunshine, Jonathan H

    2011-01-01

    Radiologists have always been considered the physicians who "control" noninvasive diagnostic imaging (NDI) and are primarily responsible for its growth. Yet nonradiologists have become increasingly aggressive in their performance and interpretation of imaging. The purpose of this study was to track overall Medicare payments to radiologists and nonradiologist physicians in recent years. The Medicare Part B files covering all fee-for-service physician payments for 1998 to 2008 were the data source. All codes for discretionary NDI were selected. Procedures mandated by the patient's clinical condition (eg, supervision and interpretation codes for interventional procedures, radiation therapy planning) were excluded, as were nonimaging radionuclide tests. Medicare physician specialty codes were used to identify radiologists and nonradiologists. Payments in all places of service were included. Overall Medicare NDI payments to radiologists and nonradiologist physicians from 1998 through 2008 were compared. A separate analysis of NDI payments to cardiologists was conducted, because next to radiologists, they are the highest users of imaging. In 1998, overall Part B payments to radiologists for discretionary NDI were $2.563 billion, compared with $2.020 billion to nonradiologists (ie, radiologists' payments were 27% higher). From 1998 to 2006, payments to nonradiologists increased by 166%, compared with 107% to radiologists. By 2006, payments to nonradiologists exceeded those to radiologists. By 2008, the second year after implementation of the Deficit Reduction Act, payments to radiologists had dropped by 13%, compared with 11% to nonradiologists. In 2008, nonradiologists received $4.807 billion for discretionary NDI, and radiologists received $4.638 billion. Payments to cardiologists for NDI increased by 195% from 1998 to 2006, then dropped by 8% by 2008. The growth in fee-for-service payments to nonradiologists for NDI was considerably more rapid than the growth for

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

    Directory of Open Access Journals (Sweden)

    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

  19. Non-invasive baroreflex sensitivity assessment using wavelet transfer function-based time–frequency analysis

    International Nuclear Information System (INIS)

    Keissar, K; Gilad, O; Maestri, R; Pinna, G D; La Rovere, M T

    2010-01-01

    A novel approach for the estimation of baroreflex sensitivity (BRS) is introduced based on time–frequency analysis of the transfer function (TF). The TF method (TF-BRS) is a well-established non-invasive technique which assumes stationarity. This condition is difficult to meet, especially in cardiac patients. In this study, the classical TF was replaced with a wavelet transfer function (WTF) and the classical coherence was replaced with wavelet transform coherence (WTC), adding the time domain as an additional degree of freedom with dynamic error estimation. Error analysis and comparison between WTF-BRS and TF-BRS were performed using simulated signals with known transfer function and added noise. Similar comparisons were performed for ECG and blood pressure signals, in the supine position, of 19 normal subjects, 44 patients with a history of previous myocardial infarction (MI) and 45 patients with chronic heart failure. This yielded an excellent linear association (R > 0.94, p < 0.001) for time-averaged WTF-BRS, validating the new method as consistent with a known method. The additional advantage of dynamic analysis of coherence and TF estimates was illustrated in two physiological examples of supine rest and change of posture showing the evolution of BRS synchronized with its error estimations and sympathovagal balance

  20. Functional photoacoustic tomography for neonatal brain imaging: developments and challenges

    Science.gov (United States)

    Hariri, Ali; Tavakoli, Emytis; Adabi, Saba; Gelovani, Juri; Avanaki, Mohammad R. N.

    2017-03-01

    Transfontanelle ultrasound imaging (TFUSI) is a routine diagnostic brain imaging method in infants who are born prematurely, whose skull bones have not completely fused together and have openings between them, so-called fontanelles. Open fontanelles in neonates provide acoustic windows, allowing the ultrasound beam to freely pass through. TFUSI is used to rule out neurological complications of premature birth including subarachnoid hemorrhage (SAH), intraventricular (IVH), subependimal (SEPH), subdural (SDH) or intracerebral (ICH) hemorrhages, as well as hypoxic brain injuries. TFUSI is widely used in the clinic owing to its low cost, safety, accessibility, and noninvasive nature. Nevertheless, the accuracy of TFUSI is limited. To address several limitations of current clinical imaging modalities, we develop a novel transfontanelle photoacoustic imaging (TFPAI) probe, which, for the first time, should allow for non-invasive structural and functional imaging of the infant brain. In this study, we test the feasibility of TFPAI for detection of experimentally-induced intra ventricular and Intraparenchymal hemorrhage phantoms in a sheep model with a surgically-induced cranial window which will serve as a model of neonatal fontanelle. This study is towards using the probe we develop for bedside monitoring of neonates with various disease conditions and complications affecting brain perfusion and oxygenation, including apnea, asphyxia, as well as for detection of various types of intracranial hemorrhages (SAH, IVH, SEPH, SDH, ICH).

  1. Effect of prophylactic non-invasive mechanical ventilation on functional capacity after heart valve replacement: a clinical trial

    Directory of Open Access Journals (Sweden)

    Amaro Afrânio de Araújo-Filho

    Full Text Available OBJECTIVE: During cardiac surgery, several factors contribute to the development of postoperative pulmonary complications. Non-invasive ventilation is a promising therapeutic tool for improving the functionality of this type of patient. The aim of this study is to evaluate the functional capacity and length of stay of patients in a nosocomial intensive care unit who underwent prophylactic non-invasive ventilation after heart valve replacement. METHOD: The study was a controlled clinical trial, comprising 50 individuals of both sexes who were allocated by randomization into two groups with 25 patients in each group: the control group and experimental group. After surgery, the patients were transferred to the intensive care unit and then participated in standard physical therapy, which was provided to the experimental group after 3 applications of non-invasive ventilation within the first 26 hours after extubation. For non-invasive ventilation, the positive pressure was 10 cm H2O, with a duration of 1 hour. The evaluation was performed on the 7th postoperative day/discharge and included a 6-minute walk test. The intensive care unit and hospitalization times were monitored in both groups. Brazilian Registry of Clinical Trials (REBeC: RBR number 8bxdd3. RESULTS: Analysis of the 6-minute walk test showed that the control group walked an average distance of 264.34±76 meters and the experimental group walked an average distance of 334.07±71 meters (p=0.002. The intensive care unit and hospitalization times did not differ between the groups. CONCLUSION: Non-invasive ventilation as a therapeutic resource was effective toward improving functionality; however, non-invasive ventilation did not influence the intensive care unit or hospitalization times of the studied cardiac patients.

  2. Non-invasive characterization of normal and pathological tissues through dynamic infrared imaging in the hamster cheek pouch oral cancer model

    Science.gov (United States)

    Herrera, María. S.; Monti Hughes, Andrea; Salva, Natalia; Padra, Claudio; Schwint, Amanda; Santa Cruz, Gustavo A.

    2017-05-01

    Biomedical infrared thermography, a non-invasive and functional imaging method, provides information on the normal and abnormal status and response of tissues in terms of spatial and temporal variations in body infrared radiance. It is especially attractive in cancer research due to the hypervascular and hypermetabolic activity of solid tumors. Moreover, healthy tissues like skin or mucosa exposed to radiation can be examined since inflammation, changes in water content, exudation, desquamation, erosion and necrosis, between others, are factors that modify their thermal properties. In this work we performed Dynamic Infrared Imaging (DIRI) to contribute to the understanding and evaluation of normal tissue, tumor and precancerous tissue response and radiotoxicity in an in vivo model, the hamster cheek pouch, exposed to Boron Neutron Capture Therapy. In this study, we particularly focused on the observation of temperature changes under forced transient conditions associated with mass moisture transfer in the tissue-air interface, in each tissue with or without treatment. We proposed a simple mathematical procedure that considerers the heat transfer from tissue to ambient through convection and evaporation to model the transient (exponential decay o recover) thermal study. The data was fitted to determined the characteristic decay and recovery time constants of the temperature as a function of time. Also this model allowed to explore the mass flux of moisture, as a degree of evaporation occurring on the tissue surface. Tissue thermal responses under provocation tests could be used as a non-invasive method to characterize tissue physiology.

  3. Combined MR and Optical Imaging System for Noninvasive Tumor Characterization and Quantification of Oxygenation Gain Factor in a Breast Cancer Animal Model

    National Research Council Canada - National Science Library

    Shafiiha, Roshanak

    2007-01-01

    This study proposes to modify and improve an existing MR-compatible optical tomography system that is used for non-invasive tumor characterization and provides higher sensitivity and specificity for cancer imaging...

  4. Noninvasive imaging in the assessment and prevention of coronary heart disease

    International Nuclear Information System (INIS)

    Llerena Rojas, Luis Roberto; Peix Gonzalez, Amalia; Valiente Mustelier, Juan

    2011-01-01

    Echocardiography, multidetector computed tomography, magnetic resonance imaging, and nuclear cardiology can all help prevent coronary heart disease. Echocardiography can identify asymptomatic individuals who are at risk of coronary disease and who should receive aggressive preventative therapy by providing data on the carotid intima-media thickness, arterial stiffness and flow-mediated dilatation of the brachial artery. The calcium score is an independent predictor of cardiac events that influences clinical risk scores such as the Framingham risk score. By using multidetector computed tomography or magnetic resonance imaging for coronary angiography, it is possible to visualize both the lumen and vessel walls of coronary arteries and to discriminate between calcified and noncalcified atherosclerotic plaque before invasive coronary angiography is performed. With nuclear cardiology, the functional effects of atherosclerotic lesions can be evaluated by assessing perfusion and ventricular function simultaneously

  5. Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia.

    Science.gov (United States)

    Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta; Klohs, Jan

    2017-08-01

    Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia.

  6. Special Considerations for Functional Magnetic Resonance Imaging of Pediatric Populations

    Science.gov (United States)

    Kotsoni, Eleni; Byrd, Dana; Casey, BJ

    2010-01-01

    Functional MRI (fMRI) provides a non-invasive means of studying both typical and atypical brain development in vivo. However, the developmental and clinical status of the populations of interest impact how neuroimaging data should be collected, analyzed, and interpreted. In the present paper, we review methodological and theoretical issues relevant to developmental and clinical neuroimaging research and provide possible approaches for addressing each. These issues include accounting for differences in biological noise, neuroanatomy, motion, and task performance. Finally, we emphasize the importance of a converging methods approach in constraining and supporting interpretations of pediatric imaging results. PMID:16649204

  7. Right ventricular function: methodologic and clinical considerations in noninvasive scintigraphic assessment

    International Nuclear Information System (INIS)

    Manno, B.V.; Iskandrian, A.S.; Hakki, A.H.

    1984-01-01

    Right ventricular function plays an important role in many cardiac disorders. Changes in left ventricular function, right ventricular afterload and preload, cardiac medications and ischemia may affect right ventricular function. Radionuclide ventriculography permits quantitative assessment of regional and global function of the right ventricle. This assessment can be made at rest, during exercise or after pharmacologic interventions. The overlap between right ventricle and right atrium is a major limitation for gated scintigraphic techniques. The use of imaging with newer short-lived radionuclides may permit more accurate and reproducible assessment of right ventricular function by means of the first pass method. Further work in areas related to improvement of techniques and the impact of right ventricular function on prognosis is needed

  8. Noninvasive, high-speed, near-infrared imaging of the biomolecular distribution and molecular mechanism of embryonic development in fertilized fish eggs.

    Science.gov (United States)

    Ishigaki, Mika; Nishii, Takashi; Puangchit, Paralee; Yasui, Yui; Huck, Christian W; Ozaki, Yukihiro

    2017-11-22

    In this study, the distribution of biomaterials and its molecular mechanism of embryonic development in Japanese medaka fish were analyzed nondestructively and noninvasively without staining using near-infrared (NIR) imaging. The microscopic NIR imaging system used in this research was a device capable of ultra-high-speed imaging; using this system, one can acquire microscopic imaging data in a few seconds. Therefore, the medaka eggs remained alive throughout measurements and were successfully monitored in vivo. The distributions of biomolecules were examined by mapping the intensities of NIR bands resulting from lipids, proteins and water in 2 dimensions (2D). The structures of eyes, lipid bilayer membranes, micelles and water-structure differences at the interface of different substances constituting different structures on the egg were visualized. Furthermore, insights on the metabolic mechanisms of lipids and membrane functions were drawn from the biased distribution of lipoproteins and the presence of unsaturated fatty acids in the egg membrane. These results indicated the potential for NIR imaging in evaluating the biological functions and metabolic systems of cells and embryos. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Non-invasive in vivo imaging of arthritis in a collagen-induced murine model with phosphatidylserine-binding near-infrared (NIR) dye.

    Science.gov (United States)

    Chan, Marion M; Gray, Brian D; Pak, Koon Y; Fong, Dunne

    2015-03-09

    Development of non-invasive molecular imaging techniques that are based on cellular changes in inflammation has been of active interest for arthritis diagnosis. This technology will allow real-time detection of tissue damage and facilitate earlier treatment of the disease, thus representing an improvement over X-rays, which detect bone damage at the advanced stage. Tracing apoptosis, an event occurring in inflammation, has been a strategy used. PSVue 794 is a low-molecular-weight, near-infrared (NIR)-emitting complex of bis(zinc2+-dipicolylamine) (Zn-DPA) that binds to phosphatidylserine (PS), a plasma membrane anionic phospholipid that becomes flipped externally upon cell death by apoptosis. In this study, we evaluated the capacity of PSVue 794 to act as an in vivo probe for non-invasive molecular imaging assessment of rheumatoid arthritis (RA) via metabolic function in murine collagen-induced arthritis, a widely adopted animal model for RA. Male DBA/1 strain mice were treated twice with chicken collagen type II in Freund's adjuvant. Their arthritis development was determined by measuring footpad thickness and confirmed with X-ray analysis and histology. In vivo imaging was performed with the NIR dye and the LI-COR Odyssey Image System. The level of emission was compared among mice with different disease severity, non-arthritic mice and arthritic mice injected with a control dye without the Zn-DPA targeting moiety. Fluorescent emission correlated reliably with the degree of footpad swelling and the manifestation of arthritis. Ex vivo examination showed emission was from the joint. Specificity of binding was confirmed by the lack of emission when arthritic mice were given the control dye. Furthermore, the PS-binding protein annexin V displaced the NIR dye from binding, and the difference in emission was numerically measurable on a scale. This report introduces an economical alternative method for assessing arthritis non-invasively in murine models. Inflammation in

  10. 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...

  11. Non-invasive Carotid Artery Imaging to Identify the Vulnerable Plaque: Current Status and Future Goals.

    Science.gov (United States)

    Huibers, A; de Borst, G J; Wan, S; Kennedy, F; Giannopoulos, A; Moll, F L; Richards, T

    2015-11-01

    The current clinical practise to determine if a patient should undergo carotid intervention to prevent stroke is to determine the clinical features combined with degree of carotid stenosis. However, this does not accurately determine the individual patient's risk for future stroke. A thin fibrous cap, a large lipid core, high macrophage count, and intraplaque haemorrhage have all been identified as markers of the so-called "vulnerable" plaque being related to a higher stroke risk. There is a need to assess the accuracy of in vivo imaging to identify vulnerable plaque characteristics, thereby enabling in vivo risk stratification to guide clinical decision-making. The aim of this topical review is to assess the roles of currently available imaging modalities that are applied in clinical practice and those experimental techniques that are close to clinical translation in defining carotid plaque characteristics and in informing clinical practice. Ultrasound is a low cost and ready available low-risk tool, but it lacks the accuracy to reliably detect individual plaque components and characteristics. Computed tomography is considered to be the best imaging technique to identify calcification in the carotid plaque. Magnetic resonance imaging (MRI) can identify most described plaque characteristics with moderate to good agreement. Positron emission tomography allows assessment of specific metabolic functions with tracers labelled with positron emitting radio-isotopes, but limited spatial resolution makes anatomic precision imprecise. MRI has demonstrated the most potential, with good sensitivity and specificity for most plaque characteristics. However, currently there is no single imaging modality that can reliably identify the vulnerable plaque in relation to development of future stroke. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  12. 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.

  13. Non-invasive skin oxygenation imaging using a multi-spectral camera system: effectiveness of various concentration algorithms applied on human skin

    Science.gov (United States)

    Klaessens, John H. G. M.; Noordmans, Herke Jan; de Roode, Rowland; Verdaasdonk, Rudolf M.

    2009-02-01

    This study describes noninvasive noncontact methods to acquire and analyze functional information from the skin. Multispectral images at several selected wavelengths in the visible and near infrared region are collected and used in mathematical methods to calculate concentrations of different chromophores in the epidermis and dermis of the skin. This is based on the continuous wave Near Infrared Spectroscopy method, which is a well known non-invasive technique for measuring oxygenation changes in the brain and in muscle tissue. Concentration changes of hemoglobin (dO2Hb, dHHb and dtHb) can be calculated from light attenuations using the modified Lambert Beer equation. We applied this technique on multi-spectral images taken from the skin surface using different algorithms for calculating changes in O2Hb, HHb and tHb. In clinical settings, the imaging of local oxygenation variations and/or blood perfusion in the skin can be useful for e.g. detection of skin cancer, detection of early inflammation, checking the level of peripheral nerve block anesthesia, study of wound healing and tissue viability by skin flap transplantations. Images from the skin are obtained with a multi-spectral imaging system consisting of a 12-bit CCD camera in combination with a Liquid Crystal Tunable Filter. The skin is illuminated with either a broad band light source or a tunable multi wavelength LED light source. A polarization filter is used to block the direct reflected light. The collected multi-spectral imaging data are images of the skin surface radiance; each pixel contains either the full spectrum (420 - 730 nm) or a set of selected wavelengths. These images were converted to reflectance spectra. The algorithms were validated during skin oxygen saturation changes induced by temporary arm clamping and applied to some clinical examples. The initial results with the multi-spectral skin imaging system show good results for detecting dynamic changes in oxygen concentration. However, the

  14. A simultaneous multimodal imaging system for tissue functional parameters

    Science.gov (United States)

    Ren, Wenqi; Zhang, Zhiwu; Wu, Qiang; Zhang, Shiwu; Xu, Ronald

    2014-02-01

    Simultaneous and quantitative assessment of skin functional characteristics in different modalities will facilitate diagnosis and therapy in many clinical applications such as wound healing. However, many existing clinical practices and multimodal imaging systems are subjective, qualitative, sequential for multimodal data collection, and need co-registration between different modalities. To overcome these limitations, we developed a multimodal imaging system for quantitative, non-invasive, and simultaneous imaging of cutaneous tissue oxygenation and blood perfusion parameters. The imaging system integrated multispectral and laser speckle imaging technologies into one experimental setup. A Labview interface was developed for equipment control, synchronization, and image acquisition. Advanced algorithms based on a wide gap second derivative reflectometry and laser speckle contrast analysis (LASCA) were developed for accurate reconstruction of tissue oxygenation and blood perfusion respectively. Quantitative calibration experiments and a new style of skinsimulating phantom were designed to verify the accuracy and reliability of the imaging system. The experimental results were compared with a Moor tissue oxygenation and perfusion monitor. For In vivo testing, a post-occlusion reactive hyperemia (PORH) procedure in human subject and an ongoing wound healing monitoring experiment using dorsal skinfold chamber models were conducted to validate the usability of our system for dynamic detection of oxygenation and perfusion parameters. In this study, we have not only setup an advanced multimodal imaging system for cutaneous tissue oxygenation and perfusion parameters but also elucidated its potential for wound healing assessment in clinical practice.

  15. Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

    OpenAIRE

    Yao, Junjie; Xia, Jun; Maslov, Konstantin I.; Nasiriavanaki, Mohammadreza; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

    2012-01-01

    We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood–brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for ...

  16. 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 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.

  17. Noninvasive assessment of intracranial pressure in dogs by use of biomechanical response behavior, diagnostic imaging, and finite element analysis.

    Science.gov (United States)

    Madison, Adrienne M; Sharma, Ajay; Haidekker, Mark A

    2015-08-01

    OBJECTIVE :To develop a novel method for use of diagnostic imaging, finite element analysis (FEA), and simulated biomechanical response behavior of brain tissue in noninvasive assessment and estimation of intracranial pressure (ICP) of dogs. MRI data for 5 dogs. MRI data for 5 dogs (1 with a geometrically normal brain that had no detectable signs of injury or disease and 4 with various degrees of geometric abnormalities) were obtained from a digital imaging archiving and communication system database. Patient-specific 3-D models composed of exact brain geometries were constructed from MRI images. Finite element analysis was used to simulate and observe patterns of nonlinear biphasic biomechanical response behavior of geometrically normal and abnormal canine brains at various levels of decreasing cerebral perfusion pressure and increasing ICP. Changes in biomechanical response behavior were detected with FEA for decreasing cerebral perfusion pressure and increasing ICP. Abnormalities in brain geometry led to observable changes in deformation and biomechanical response behavior for increased ICP, compared with results for geometrically normal brains. In this study, patient-specific critical ICP was identified, which could be useful as a method to predict the onset of brain herniation. Results indicated that it was feasible to apply FEA to brain geometry obtained from MRI data of clinical patients and to use biomechanical response behavior resulting from increased ICP as a diagnostic and prognostic method to noninvasively assess or classify levels of brain injury in clinical veterinary settings.

  18. High resolution multiplexed functional imaging in live embryos (Conference Presentation)

    Science.gov (United States)

    Xu, Dongli; Zhou, Weibin; Peng, Leilei

    2017-02-01

    Fourier multiplexed fluorescence lifetime imaging (FmFLIM) scanning laser optical tomography (FmFLIM-SLOT) combines FmFLIM and Scanning laser optical tomography (SLOT) to perform multiplexed 3D FLIM imaging of live embryos. The system had demonstrate multiplexed functional imaging of zebrafish embryos genetically express Foster Resonant Energy Transfer (FRET) sensors. However, previous system has a 20 micron resolution because the focused Gaussian beam diverges quickly from the focused plane, makes it difficult to achieve high resolution imaging over a long projection depth. Here, we present a high-resolution FmFLIM-SLOT system with achromatic Bessel beam, which achieves 3 micron resolution in 3D deep tissue imaging. In Bessel-FmFLIM-SLOT, multiple laser excitation lines are firstly intensity modulated by a Michelson interferometer with a spinning polygon mirror optical delay line, which enables Fourier multiplexed multi-channel lifetime measurements. Then, a spatial light modulator and a prism are used to transform the modulated Gaussian laser beam to an achromatic Bessel beam. The achromatic Bessel beam scans across the whole specimen with equal angular intervals as sample rotated. After tomography reconstruction and the frequency domain lifetime analysis method, both the 3D intensity and lifetime image of multiple excitation-emission can be obtained. Using Bessel-FmFLIM-SLOT system, we performed cellular-resolution FLIM tomography imaging of live zebrafish embryo. Genetically expressed FRET sensors in these embryo will allow non-invasive observation of multiple biochemical processes in vivo.

  19. Functional Photoacoustic Imaging of Gastric Acid Secretion Using pH-Responsive Polyaniline Nanoprobes.

    Science.gov (United States)

    Li, Junwei; Xiao, Hong; Yoon, Soon Joon; Liu, Chengbo; Matsuura, Drew; Tai, Wanyi; Song, Liang; O'Donnell, Matthew; Cheng, Du; Gao, Xiaohu

    2016-09-01

    A stomach functional imaging technique based on photoacoustics achieves noninvasive gastric acid secretory assessment utilizing pH-responsive polyaniline nanoprobes. A testing protocol mimicking clinical practice is established using a mouse model. After imaging, the nanoprobes are excreted outside the body without inducing systematic toxicity. Further optimization and translation of this technology can help alleviate patients' suffering and side effects. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Magnetocardiographic classification and non-invasive electro-anatomical imaging of outflow tract ventricular arrhythmias in recreational sport activity practitioners.

    Science.gov (United States)

    Lombardi, Gianmarco; Sorbo, Anna Rita; Guida, Gianluigi; La Brocca, Lara; Fenici, Riccardo; Brisinda, Donatella

    2018-02-16

    Ventricular arrhythmias (VAs) with left bundle-branch-block and inferior axis morphology (LBBB-IA), suggestive of outflow tract (OT) origin, are a challenge in sports medicine because they can be benign or expression of a silent cardiomyopathy. Non-invasive classification is essential to plan ablation strategy if required. We aimed to evaluating magnetocardiographic (MCG) discrimination of OT-VAs site of origin (SoO). MCG and ECG data of 26 sports activity practitioners, with OT-VAs were analyzed. OT-VAs-SoO was classified with discriminant analysis (DA) of 8 MCG parameters and with invasively-validated ECG algorithms. MCG inverse source-localization merged with magnetic resonance (CMR) provided three-dimensional electro-anatomical imaging (MCG 3D-EAI). ECG classification was univocal in 73%. MCG-DA differentiated right ventricular OT from aortic sinus cusp VAs, with 94.7% accuracy. MCG 3D-EAI confirmed OT-VAs-SoO in CMR images. In cases undergoing ablation, MCG 3D-EAI was confirmed by CARTO 3D-EAI. MCG-DA improves non-invasive classification of OT-VAs-SoO. Further comparison with interventional results is required. Copyright © 2018. Published by Elsevier Inc.

  1. Analysis of microparticle penetration into human and porcine skin: non-invasive imaging with multiphoton excitation microscopy

    Science.gov (United States)

    Mulholland, William J.; Kendall, Mark A.; Bellhouse, Brian J.; White, Nick

    2002-06-01

    At the University of Oxford and PowderJect Pharmaceuticals plc, a unique form of needle-free injection technology has been developed. Powdered vaccines and drugs in micro-particle form are accelerated in a high-speed gas flow to sufficient velocity to enter the skin, subsequently achieving a pharmaceutical effect. To optimize the delivery of vaccines and drugs with this method a detailed understanding of the interactive processes that occur between the microparticles and the skin is necessary. Investigations to date of micro-particle delivery into excised human and animal tissue have involved image analyses of histology sections. In the present study, a series of investigations were conducted on excised human and porcine skin using the technique of Multi-Photon fluorescence excitation Microscopy (MPM) to image particles and skin structures post-penetration. Micro-particles of various size and composition were imaged with infrared laser excitation. Three-dimensional images of stratum corneum and epidermal cell deformation due to micro-particle penetration were obtained. Measurements of micro-particle penetration depth taken from z-scan image stacks were used to successfully quantify micro-particle distribution within the skin, without invasively disrupting the skin target. This study has shown that MPM has great potential for the non-invasive imaging of particle skin interactive processes that occur with the transdermal delivery of powdered micro-particle vaccines and drugs.

  2. A Non-invasive detection of lung cancer combined virtual gas sensors array with imaging recognition technique.

    Science.gov (United States)

    Chen, Xing; Cao, Mingfu; Hao, Yan; Li, Yi; Wang, Ping; Ying, Kejing; Pan, Hongming

    2005-01-01

    In this paper, we propose a non-invasive detection method of lung cancer combined with a sort of virtual SAW gas sensors array and imaging recognition method. A patient's breath goes through an electronic nose with solid phase micro extraction (SPME) and capillary column for pre-concentration and separation of volatile organic compounds (VOCs) respectively, a pair of SAW sensors one coated with a thin Poly-isobutylene (PIB) film is connected to the output of capillary column port for chemical compounds detection. A lung cancer tissues' culture medium study is also proposed for pathology validation. 11 VOCs which are considered as the biomarkers of lung cancer can be detected qualitatively and quantitatively. Finally these 11 VOCs are used to diagnose lung cancer patients in Run Run Shaw hospital by our e-nose with an improved artificial neural network (ANN) algorithm combined with imaging method for pattern recognition.

  3. Functional and perfusion magnetic resonance imaging at 3 tesla

    CERN Document Server

    Klarhoefer, M

    2001-01-01

    This thesis deals with the development and optimization of fast magnetic resonance imaging (MRI) methods for non-invasive functional studies of the human brain and perfusion imaging on a 3 Tesla (T) whole body NMR system. The functional MRI (fMRI) experiments performed showed that single-shot multi-echo EPI and spiral imaging techniques provide fast tools to obtain information about T2* distributions during functional activation in the human brain. Both sequences were found to be useful in the separation of different sources contributing to the functional MR signal like inflow or susceptibility effects in the various vascular environments. An fMRI study dealing with the involvement of prefrontal brain regions in movement preparation lead to inconsistent results. It could not be clarified if these were caused by problems during a spatial normalization process of the individual brains or if the functional paradigm, using very short inter-stimulus intervals, was not suited for the problem investigated. Blood flo...

  4. Functional anatomy and pathophysiologic principles in mitral regurgitation: Non-invasive assessment.

    Science.gov (United States)

    Maréchaux, Sylvestre; Illman, Jeffery E; Huynh, James; Michelena, Hector I; Nkomo, Vuyisile T; Tribouilloy, Christophe

    Mitral regurgitation (MR) is the most prevalent cause of valvular heart disease (VHD) in western countries. In the Euro Heart Survey on VHD, MR was the second most common heart VHD requiring surgery. It is also the most common form of VHD in community and population-based studies from the United States. The categorization of MR based on causes and mechanisms is a major determinant of clinical outcome, of possible therapies for the MR and of the effectiveness of these therapies. Surgical mitral valve (MV) repair has been shown to improve survival in patients with severe primary MR compared with MV replacement. In addition, new percutaneous repair and replacement procedures have been recently developed. Hence, accurate understanding of the functional anatomy of the MV and the pathophysiologic principles underlying MR is needed to appropriately target valve lesions. Recent advances in cardiac imaging have allowed to deeply strengthen the knowledge of the function of the MV. The present review aims at describing the functional anatomy and pathophysiology of MR through different cardiac imaging modalities. Copyright © 2017 Anesthesia History Association. Published by Elsevier Inc. All rights reserved.

  5. 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.

  6. 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.

  7. In vivo 18F-fluorodeoxyglucose positron emission tomography imaging provides a noninvasive measure of carotid plaque inflammation in patients.

    Science.gov (United States)

    Tawakol, Ahmed; Migrino, Raymond Q; Bashian, Gregory G; Bedri, Shahinaz; Vermylen, David; Cury, Ricardo C; Yates, Denise; LaMuraglia, Glenn M; Furie, Karen; Houser, Stuart; Gewirtz, Henry; Muller, James E; Brady, Thomas J; Fischman, Alan J

    2006-11-07

    Given the importance of inflammation in atherosclerosis, we sought to determine if atherosclerotic plaque inflammation could be measured noninvasively in humans using positron emission tomography (PET). Earlier PET studies using fluorodeoxyglucose (FDG) demonstrated increased FDG uptake in atherosclerotic plaques. Here we tested the ability of FDG-PET to measure carotid plaque inflammation in patients who subsequently underwent carotid endarterectomy (CEA). Seventeen patients with severe carotid stenoses underwent FDG-PET imaging 3 h after FDG administration (13 to 25 mCi), after which carotid plaque FDG uptake was determined as the ratio of plaque to blood activity (target to background ratio, TBR). Less than 1 month after imaging, subjects underwent CEA, after which carotid specimens were processed to identify macrophages (staining with anti-CD68 antibodies). There was a significant correlation between the PET signal from the carotid plaques and the macrophage staining from the corresponding histologic sections (r = 0.70; p < 0.0001). When mean FDG uptake (mean TBR) was compared with mean inflammation (mean percentage CD68 staining) for each of the 17 patients, the correlation was even stronger (r = 0.85; p < 0.0001). Fluorodeoxyglucose uptake did not correlate with plaque area, plaque thickness, or area of smooth muscle cell staining. We established that FDG-PET imaging can be used to assess the severity of inflammation in carotid plaques in patients. If subsequent natural history studies link increased FDG-PET activity in carotid arteries with clinical events, this noninvasive measure could be used to identify a subset of patients with carotid atherosclerosis in need of intensified medical therapy or carotid artery intervention to prevent stroke.

  8. Frontal Eye Field, Where Art Thou? Anatomy, function and non-invasive manipulation of frontal regions involved in eye movements and associated cognitive operations

    Directory of Open Access Journals (Sweden)

    Marine eVernet

    2014-08-01

    Full Text Available The planning, control and execution of eye movements in 3D space relies on a distributed system of cortical and subcortical brain regions. Within this network, the Eye Fields have been described in animals as cortical regions in which electrical stimulation is able to trigger eye movements and influence their latency or accuracy. This review will focus on the Frontal Eye Field (FEF a hub region located in Humans in the vicinity of the pre-central sulcus and the dorsal-most portion of the superior frontal sulcus. The straightforward localization of the FEF through electrical stimulation in animals is difficult to translate to the healthy human brain, particularly with non-invasive neuroimaging techniques. Hence, in the first part of this review, we will describe attempts made to characterize the anatomical localization of this area in the human brain. The outcome of functional Magnetic Resonance Imaging (fMRI, Magneto-encephalography (MEG and particularly, non-invasive mapping methods such a Transcranial Magnetic Stimulation (TMS will be described and the variability of FEF localization across individuals and mapping techniques will be discussed. In the second part of this review, we will address the role of the FEF. We will explore its involvement both in the physiology of fixation, saccade, pursuit and vergence movements and in associated cognitive processes such as attentional orienting, visual awareness and perceptual modulation. Finally in the third part, we will review recent evidence suggesting the high level of malleability and plasticity of these regions and associated networks to non-invasive stimulation. The exploratory, diagnostic and therapeutic interest of such interventions for the modulation and improvement of perception in 3D space will be discussed.

  9. Physiology for the pulmonary functional imager

    International Nuclear Information System (INIS)

    Levin, David L.; Schiebler, Mark L.; Hopkins, Susan R.

    2017-01-01

    Highlights: • An understanding of the relevant pulmonary physiology is crucial to functional lung imaging. • Spatial resolution for pulmonary functional imaging can be substantially less than that used for anatomic/clinical imaging. • Regional deformation of the lung under the influence of gravity significantly affects the measurement of pulmonary perfusion. • Large vessels identified on perfusion imaging do not represent local blood flow. • Pulmonary diseases are typically characterized by a change in the matching of ventilation and perfusion. - Abstract: As pulmonary functional imaging moves beyond the realm of the radiologist and physicist, it is important that imagers have a common language and understanding of the relevant physiology of the lung. This review will focus on key physiological concepts and pitfalls relevant to functional lung imaging.

  10. Non-Invasive Assessment of Hepatic Fibrosis by Elastic Measurement of Liver Using Magnetic Resonance Tagging Images

    Directory of Open Access Journals (Sweden)

    Xuejun Zhang

    2018-03-01

    Full Text Available To date, the measurement of the stiffness of liver requires a special vibrational tool that limits its application in many hospitals. In this study, we developed a novel method for automatically assessing the elasticity of the liver without any use of contrast agents or mechanical devices. By calculating the non-rigid deformation of the liver from magnetic resonance (MR tagging images, the stiffness was quantified as the displacement of grids on the liver image during a forced exhalation cycle. Our methods include two major processes: (1 quantification of the non-rigid deformation as the bending energy (BE based on the thin-plate spline method in the spatial domain and (2 calculation of the difference in the power spectrum from the tagging images, by using fast Fourier transform in the frequency domain. By considering 34 cases (17 normal and 17 abnormal liver cases, a remarkable difference between the two groups was found by both methods. The elasticity of the liver was finally analyzed by combining the bending energy and power spectral features obtained through MR tagging images. The result showed that only one abnormal case was misclassified in our dataset, which implied our method for non-invasive assessment of liver fibrosis has the potential to reduce the traditional liver biopsy.

  11. Non-invasive imaging and monitoring of rodent retina using simultaneous dual-band optical coherence tomography

    Science.gov (United States)

    Cimalla, Peter; Burkhardt, Anke; Walther, Julia; Hoefer, Aline; Wittig, Dierk; Funk, Richard; Koch, Edmund

    2011-03-01

    Spectral domain dual-band optical coherence tomography for simultaneous imaging of rodent retina in the 0.8 μm and 1.3 μm wavelength region and non-invasive monitoring of the posterior eye microstructure in the field of retinal degeneration research is demonstrated. The system is illuminated by a supercontinuum laser source and allows three-dimensional imaging with high axial resolution better than 3.8 μm and 5.3 μm in tissue at 800 nm and 1250 nm, respectively, for precise retinal thickness measurements. A fan-shaped scanning pattern with the pivot point close to the eye's pupil and a contact lens are applied to obtain optical access to the eye's fundus. First in vivo experiments in a RCS (royal college of surgeons) rat model with gene-related degeneration of the photoreceptor cells show good visibility of the retinal microstructure with sufficient contrast for thickness measurement of individual retinal layers. An enhanced penetration depth at 1250 nm is clearly identifiable revealing sub-choroidal structures that are not visible at 800 nm. Furthermore, additional simultaneous imaging at 1250 nm improves image quality by frequency compounding speckle noise reduction. These results are encouraging for time course studies of the rodent retina concerning its development related to disease progression and treatment response.

  12. Non-invasive measurement and imaging of tissue iron oxide nanoparticle concentrations in vivo using proton relaxometry

    International Nuclear Information System (INIS)

    St Pierre, T G; Clark, P R; Chua-anusorn, W; Fleming, A; Pardoe, H; Jeffrey, G P; Olynyk, J K; Pootrakul, P; Jones, S; Moroz, P

    2005-01-01

    Magnetic nanoparticles and microparticles can be found in biological tissues for a variety of reasons including pathological deposition of biogenic particles, administration of synthetic particles for scientific or clinical reasons, and the inclusion of biogenic magnetic particles for the sensing of the geomagnetic field. In applied magnetic fields, the magnetisation of tissue protons can be manipulated with radiofrequency radiation such that the macroscopic magnetisation of the protons precesses freely in the plane perpendicular to the applied static field. The presence of magnetic particles within tissue enhances the rate of dephasing of proton precession with higher concentrations of particles resulting in higher dephasing rates. Magnetic resonance imaging instruments can be used to measure and image the rate of decay of spin echo recoverable proton transverse magnetisation (R 2 ) within tissues enabling the measurement and imaging of magnetic particle concentrations with the aid of suitable calibration curves. Applications include the non-invasive measurement of liver iron concentrations in iron-overload disorders and measurement and imaging of magnetic particle concentrations used in magnetic hyperthermia therapy. Future applications may include the tracking of magnetically labelled drugs or biomolecules and the measurement of fibrotic liver damage

  13. Functional imaging of neurocognitive dysfunction in attention deficit hyperactivity disorder

    International Nuclear Information System (INIS)

    Wolf, I.; Tost, H.; Ruf, M.; Ende, G.

    2005-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until adulthood. Miscellaneous causes of the disorder have been discussed. Accumulating evidence from imaging- and molecular genetic studies strengthened the theory of ADHS being a predominantly inherited disorder of neurobiological origin. In the last 15 years, non-invasive brain imaging methods were successfully implemented in pediatric research. Functional magnetic resonance imaging studies gave major insight into the neurobiological correlates of executive malfunction, inhibitory deficits and psychomotoric soft signs. These findings are in good accordance with brain morphometric data indicating a significant volumetric decrease of major components of striato-thalamo-cortical feedback loops, primarily influencing prefrontal executive functioning (e.g. basal ganglia). Empirical evidence points to a broad array of associated behavioral disturbances like deficient visuomotor abilities and oculomotor dysfunctions. This paper reviews the current empirical evidence derived from prior imaging studies. Special emphasis is given to the relevance of oculomotor dysfunctions in clinical and research settings, as well as their assessment in the MR environment. (orig.) [de

  14. Stereotactic imaging in functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Hidehiro

    2012-07-01

    Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3{sup rd} ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and

  15. Stereotactic imaging in functional neurosurgery

    International Nuclear Information System (INIS)

    Hirabayashi, Hidehiro

    2012-01-01

    Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3 rd ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and MRI

  16. 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

  17. 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.

  18. Noninvasive detection of coronary artery disease by myocardial imaging with thallium-201

    International Nuclear Information System (INIS)

    Narita, Michihiro; Kurihara, Tadashi; Usami, Masahisa

    1981-01-01

    Dipyridamole-loading myocardial imaging was performed in 38 patients with coronary artery diseases(CAD). The diagnostic accuracy of this method was 66%. The combination of dipyridamole-loading and exercise stress myocardial imaging increased the diagnostic sensitivity of CAD from 71% (exercise stress imaging only) to 87%. In addition, dipyridamole-loading myocardial imaging was useful for the diagnosis of CAD in patients who could not perform exercise stree test. Chest pain and ST-segment depression were induced less often during dipyridamole administration than exercise stress test. Animal experiments showed that dipyridamole caused abnormalities in myocardial blood flow and myocardial Tl uptake distal to the critical coronary stenosis. And dipyridamole increased myocardial blood flow by 142% and myocardial Tl concentration by 62% in the normally perfused myocardial segments. Ergonovine-loading myocardial imaging was performed in 8 patients with resting angina and without significant coronary stenosis. And in all of them, ergonivine induced cold-spots on myocardial imaging with or without chest pain and ST-segment shift. Ergonovine-loading myocardial imaging was useful for the diagnosis of angina induced by coronary artery spasm. The combination of initial and delayed resting myocardial imaging was useful to differentiate the underperfused but viable myocardium from the scar. And by comparing with radionuclide angiography obtained before and after nitroglycerin(NTG) administration, ATG-loading myocardial imaging and electrocardiogram(ECG) findings in 20 patients with CAD, we demonstrated that the transient defective myocadial segments were underperfused but viable. (author)

  19. An activatable MR imaging agent reports myeloperoxidase activity in healing infarcts and detects the anti-inflammatory effects of atorvastatin on ischemia-reperfusion injury non-invasively

    Science.gov (United States)

    Nahrendorf, Matthias; Sosnovik, David; Chen, John; Panizzi, Peter; Figueiredo, Jose-Luiz; Aikawa, Elena; Libby, Peter; Swirski, Filip K.; Weissleder, Ralph

    2009-01-01

    Background: Ischemic injury of the myocardium causes timed recruitment of neutrophils and monocytes/macrophages, which produce substantial amounts of local myeloperoxidase (MPO). MPO forms reactive chlorinating species capable of inflicting oxidative stress and altering protein function by covalent modification. We have developed a small molecule, gadolinium-based activatable sensor for magnetic resonance imaging (MRI) of MPO activity (MPO-Gd). MPO-Gd is first radicalized by MPO, and then either spontaneously oligomerizes or binds to matrix proteins, all leading to enhanced spin-lattice-relaxivity and delayed wash-out kinetics. We hypothesized that MPO-imaging could be used to locally and non-invasively measure inflammatory responses after myocardial ischemia in a murine model. Methods and Results: We injected 0.3 mmol/kg of MPO-Gd (or Gd-DTPA as control) and performed MRI up to 120min later in mice 2 days after MI. Contrast-to-noise ratio (CNR, infarct versus septum) following Gd-DTPA injection peaked at 10 min, and returned to pre-injection values at 60 min. Following injection of MPO-Gd, CNR peaked later and was higher than Gd-DTPA (40.8±10.4 versus 10.5±0.2, p<0.05). MPO-imaging was validated by MRI of MPO−/− mice and correlated well with immunoreactive staining (r2=0.92, p<0.05), tissue activity by guaiacol assay (r2=0.65, p<0.001) and immunoblotting. In time course imaging, activity peaked 2 days after coronary ligation. Flow cytometry of digested infarcts detected MPO in neutrophils and monocytes/macrophages. Furthermore, serial MPO-imaging accurately tracked the anti-inflammatory effects of atorvastatin therapy after ischemia reperfusion injury. Conclusion: MPO-Gd enables in-vivo assessment of MPO activity in injured myocardium. This approach allows non-invasive evaluation of the inflammatory response to ischemia and has the potential to guide the development of novel cardioprotective therapies. PMID:18268141

  20. Non-invasive deep tissue imaging of iodine modified poly(caprolactone-co-1-4-oxepan-1,5-dione) using X-ray.

    Science.gov (United States)

    Olsen, Timothy R; Davis, Lundy L; Nicolau, Samantha E; Duncan, Caroline C; Whitehead, Daniel C; Van Horn, Brooke A; Alexis, Frank

    2015-07-01

    When biodegradable polyester devices, like sutures and screws, are implanted into the body, it is very challenging to image them in deep tissue, monitor their degradation, and detect defects. We report our recent findings on non-invasive deep tissue imaging of polyester degradation, stability and integrity using an iodinated-polycaprolactone (i-P(CLcoOPD)) X-ray imaging contrast agent. The results of experiments performed with i-P(CLcoOPD) demonstrate the feasibility to quantify in-situ polyester degradation in vitro and in vivo using rats. We also demonstrate that X-ray imaging could be used to identify and quantify physical defects, such as cracks, in polymeric implants using rabbit animal models. This approach enables non-invasive monitoring of polyester materials and is expected to become an important technology for improving the imaging of polymers at clinically relevant depths. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. 3-D spectral IP imaging: Non-invasive characterization of contaminant plumes. 1998 annual progress report

    International Nuclear Information System (INIS)

    Lesmes, D.; Morgan, F.D.; Rodi, W.

    1998-01-01

    annual SAGEEP conference (Shi et al., 1998). The authors have developed algorithms for forward modeling and inversion of spectral IP data in 3-D media. The algorithms accommodate a general earth model with a complex electrical conductivity as a function of frequency and 3-D spatial position. Using regularization and optimization techniques, the inversion algorithm obtains a 3-D image of resistivity amplitude and phase for each frequency contained in the data set. They have begun testing their algorithms on synthetic data generated from a simple model of a contaminant plume. The complex resistivity parameters of the background medium and plume are based on the laboratory results described above.'

  2. Non-invasive investigation of lower limb revascularisation using resting thallium peripheral perfusion imaging

    International Nuclear Information System (INIS)

    Earnshaw, J.J.; Hopkinson, B.R.; Makin, G.S.; Hardy, J.G.

    1986-01-01

    Resting thallium thigh and calf imaging was performed in 11 patients with lower limb ischaemia before and after revascularisation. Eight patients had successful revascularisation but in the other three the procedure failed to improve the circulation. Despite symptomatic improvement and increases in ankle systolic pressures after successful revascularisation there was no change in thallium uptake. Thallium imaging was compared with radionuclide angiography and blood pool imaging in six patients. Radionuclide angiograms confirmed the presence of well developed collateral circulation in some patients with increased thallium uptake in the symptomatic limb and in all cases the angiograms were clinically useful. There was no correlation between thallium and blood pool images. Resting lower limb blood flow did not change after revascularisation and thallium peripheral perfusion imaging did not aid the assessment of the response to lower limb revascularisation. (orig.)

  3. A non-invasive technique for the evaluation of peripheral circulatory functions in female subjects with Raynaud's phenomenon.

    Science.gov (United States)

    Mirbod, Seyed Mohammad; Sugiura, Haruo

    2017-06-08

    Japanese women now account for 43 percent of the labor force. A number of them are involved in construction, agricultural and forestry jobs. The aim of this study was to establish a non-invasive technique for the evaluation of peripheral circulatory functions in women with Raynaud's phenomenon (RP) and introduce a specific method for the assessment of vascular disturbances in females exposed to hand-transmitted vibration. The subjects of this study were 10 women with primary RP, 7 women with progressive systemic sclerosis (PSS) secondary to RP, and 17 females who were included as the control group. The evaluation of peripheral circulatory functions in all subjects was based on the values of finger blood flow (FBF) and finger skin temperature (FST) measured before, during and following a 5-min recovery period after the hand was immersed in cold water (5°C, 1 min). The measured values of FBF and FST of the primary RP group before and after the immersion test were significantly (p<0.01) lower compared to those of the control group. The technique applied in this study could be used as a non-invasive and tolerable technique to determine the digital circulatory functions in female subjects with RP.

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

    International Nuclear Information System (INIS)

    Borelli, Flavio Antonio de Oliveira; 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.

    2013-01-01

    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 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

  5. 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.

  6. 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.

  7. Use of non-invasive imaging to monitor response to aflibercept treatment in murine models of colorectal cancer liver metastases.

    Science.gov (United States)

    Fleten, Karianne G; Bakke, Kine M; Mælandsmo, Gunhild M; Abildgaard, Andreas; Redalen, Kathrine Røe; Flatmark, Kjersti

    2017-01-01

    The liver is the most frequent metastatic site in colorectal cancer (CRC), and relevant orthotopic in vivo models are needed to study the efficacy of anticancer drugs in the metastatic setting. A challenge when utilizing such models is monitoring tumor growth during the experiments. In this study, experimental liver metastases were established in nude mice by splenic injection of the CRC cell lines HT29 and HCT116, and the mice were treated with the antiangiogenic drug aflibercept. Tumor growth was monitored using magnetic resonance imaging (MRI) and bioluminescence imaging (BLI). Aflibercept treatment was well tolerated and resulted in increased animal survival in HCT116, but not in HT29, while inhibited tumor growth was observed in both models. Treatment efficacy was monitored with high precision using MRI, while BLI detected small-volume disease with high sensitivity, but was less accurate in end-stage disease. Apparent diffusion coefficient (ADC) values obtained by diffusion weighted MRI (DW-MRI) were highly predictive of treatment response, with increased ADC corresponding well with areas of necrosis observed by histological evaluation of aflibercept-treated xenografts. The results showed that the efficacy of the antiangiogenic drug aflibercept varied between the two models, possibly reflecting unique growth patterns in the liver that may be representative of human disease. Non-invasive imaging, especially MRI and DW-MRI, can be used to effectively monitor tumor growth and treatment response in orthotopic liver metastasis models.

  8. Functional and molecular imaging with MRI: potential applications in paediatric radiology

    International Nuclear Information System (INIS)

    Arthurs, Owen J.; Gallagher, Ferdia A.

    2011-01-01

    MRI is a very versatile tool for noninvasive imaging and it is particularly attractive as an imaging technique in paediatric patients given the absence of ionizing radiation. Recent advances in the field of MRI have enabled tissue function to be probed noninvasively, and increasingly MRI is being used to assess cellular and molecular processes. For example, dynamic contrast-enhanced MRI has been used to assess tissue vascularity, diffusion-weighted imaging can quantify molecular movements of water in tissue compartments and MR spectroscopy provides a quantitative assessment of metabolite levels. A number of targeted contrast agents have been developed that bind specifically to receptors on the vascular endothelium or cell surface and there are several MR methods for labelling cells and tracking cellular movements. Hyperpolarization techniques have the capability of massively increasing the sensitivity of MRI and these have been used to image tissue pH, successful response to drug treatment as well as imaging the microstructure of the lungs. Although there are many challenges to be overcome before these techniques can be translated into routine paediatric imaging, they could potentially be used to aid diagnosis, predict disease outcome, target biopsies and determine treatment response noninvasively. (orig.)

  9. Functional imaging of the multidrug resistance in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Tae [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of)

    2001-07-01

    Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are improtant factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP in vivo. Single photon emission tomograpy (SPECT) and positron emission tomograpy (PET) are available for the detection of Pgp and MRP-mediated transport. {sup 99m}Tc-sestaMIBI and other {sup 99m}Tc-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies of tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with {sup 11}C have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-{sup (11}C]acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transportes in vivo.

  10. Non-invasive assessment of coronary artery disease with stress thallium-201 myocardial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Hirose, Yoshiaki; Hamada, Seiki; Maeno, Masakazu; Takahashi, Nobukazu; Hayashida, Kohei; Takamiya, Makoto; Miyazaki, Shun-ich; Nonogi, Hiroshi [National Cardiovascular Center, Suita, Osaka (Japan)

    1995-02-01

    Recent studies have reported a low specificity of stress thallium-201 myocardial imaging in the diagnosis of coronary artery disease. Thus this study was undertaken to reassess the ability of stress thallium-201 myocardial imaging to detect deseased coronary vessels. The subjects were 469 patients, who consisted of 397 with a significant {>=}75% stenosis and the other 72 with normal coronary vessels on coronary arteriography done within 6 months before and after thallium imaging. Using the coronary arteriogram as the arbiter, the sensitivity and specificity of stress thallium imaging were 91% and 43%, respectively. Forty-one patients with no angiographic evidence of coronary stenosis were assessed as having coronary stenosis on thallium imaging (false-positive cases). All the 41 patients had cardiovascular diseases or symptoms, such as hypertrophic cardiomyopathy, complete left bundle branch block, chest pain of unknown etiology, and abnormalities on stress ECG. This suggested the possibility that dysfunctional segments may be manifested by exercise stress even though these are not shown on coronary arteriography at rest. Thus the low specificity of stress thallium-201 myocardial imaging in the diagnosis of coronary artery disease may not contribute to the essential disadvantage of thallium imaging, but may reflect dysfunctional segments that are not shown by morphological manifestation of coronary arteriography. (N.K.).

  11. Noninvasive imaging of the human rod photoreceptor mosaic using a confocal adaptive optics scanning ophthalmoscope

    Science.gov (United States)

    Dubra, Alfredo; Sulai, Yusufu; Norris, Jennifer L.; Cooper, Robert F.; Dubis, Adam M.; Williams, David R.; Carroll, Joseph

    2011-01-01

    The rod photoreceptors are implicated in a number of devastating retinal diseases. However, routine imaging of these cells has remained elusive, even with the advent of adaptive optics imaging. Here, we present the first in vivo images of the contiguous rod photoreceptor mosaic in nine healthy human subjects. The images were collected with three different confocal adaptive optics scanning ophthalmoscopes at two different institutions, using 680 and 775 nm superluminescent diodes for illumination. Estimates of photoreceptor density and rod:cone ratios in the 5°–15° retinal eccentricity range are consistent with histological findings, confirming our ability to resolve the rod mosaic by averaging multiple registered images, without the need for additional image processing. In one subject, we were able to identify the emergence of the first rods at approximately 190 μm from the foveal center, in agreement with previous histological studies. The rod and cone photoreceptor mosaics appear in focus at different retinal depths, with the rod mosaic best focus (i.e., brightest and sharpest) being at least 10 μm shallower than the cones at retinal eccentricities larger than 8°. This study represents an important step in bringing high-resolution imaging to bear on the study of rod disorders. PMID:21750765

  12. Non-invasive assessment of coronary artery disease with stress thallium-201 myocardial imaging

    International Nuclear Information System (INIS)

    Ishida, Yoshio; Hirose, Yoshiaki; Hamada, Seiki; Maeno, Masakazu; Takahashi, Nobukazu; Hayashida, Kohei; Takamiya, Makoto; Miyazaki, Shun-ich; Nonogi, Hiroshi

    1995-01-01

    Recent studies have reported a low specificity of stress thallium-201 myocardial imaging in the diagnosis of coronary artery disease. Thus this study was undertaken to reassess the ability of stress thallium-201 myocardial imaging to detect deseased coronary vessels. The subjects were 469 patients, who consisted of 397 with a significant ≥75% stenosis and the other 72 with normal coronary vessels on coronary arteriography done within 6 months before and after thallium imaging. Using the coronary arteriogram as the arbiter, the sensitivity and specificity of stress thallium imaging were 91% and 43%, respectively. Forty-one patients with no angiographic evidence of coronary stenosis were assessed as having coronary stenosis on thallium imaging (false-positive cases). All the 41 patients had cardiovascular diseases or symptoms, such as hypertrophic cardiomyopathy, complete left bundle branch block, chest pain of unknown etiology, and abnormalities on stress ECG. This suggested the possibility that dysfunctional segments may be manifested by exercise stress even though these are not shown on coronary arteriography at rest. Thus the low specificity of stress thallium-201 myocardial imaging in the diagnosis of coronary artery disease may not contribute to the essential disadvantage of thallium imaging, but may reflect dysfunctional segments that are not shown by morphological manifestation of coronary arteriography. (N.K.)

  13. 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

    Stem cell therapy for degenerative diseases, including ischemic heart disease is now a clinical reality. In the search for the optimal cell type for each patient category, many different stem cell subpopulations have been used. In addition, different cell processing procedures and delivery methods......, migration and efficacy of the transplanted cells. Great effort is being made in finding new and better imaging techniques for different imaging modalities, and much have already been learned. But there are still many unanswered questions. In this review, we give an overview of the imaging modalities used...

  14. 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.

  15. A Noninvasive Body Setup Method for Radiotherapy by Using a Multimodal Image Fusion Technique.

    Science.gov (United States)

    Zhang, Jie; Chen, Ying; Chen, Yunxia; Wang, Chenchen; Cai, Jing; Chu, Kaiyue; Jin, Jianhua; Ge, Yun; Huang, Xiaolin; Guan, Yue; Li, Weifeng

    2017-12-01

    To minimize the mismatch error between patient surface and immobilization system for tumor location by a noninvasive patient setup method. The method, based on a point set registration, proposes a shift for patient positioning by integrating information of the computed tomography scans and that of optical surface landmarks. An evaluation of the method included 3 areas: (1) a validation on a phantom by estimating 100 known mismatch errors between patient surface and immobilization system. (2) Five patients with pelvic tumors were considered. The tumor location errors of the method were measured using the difference between the proposal shift of cone-beam computed tomography and that of our method. (3) The collected setup data from the evaluation of patients were compared with the published performance data of other 2 similar systems. The phantom verification results showed that the method was capable of estimating mismatch error between patient surface and immobilization system in a precision of <0.22 mm. For the pelvic tumor, the method had an average tumor location error of 1.303, 2.602, and 1.684 mm in left-right, anterior-posterior, and superior-inferior directions, respectively. The performance comparison with other 2 similar systems suggested that the method had a better positioning accuracy for pelvic tumor location. By effectively decreasing an interfraction uncertainty source (mismatch error between patient surface and immobilization system) in radiotherapy, the method can improve patient positioning precision for pelvic tumor.

  16. Ultrasound imaging of propagation of myocardial contraction for non-invasive identification of myocardial ischemia

    Science.gov (United States)

    Matsuno, Yuya; Taki, Hirofumi; Yamamoto, Hiroaki; Hirano, Michinori; Morosawa, Susumu; Shimokawa, Hiroaki; Kanai, Hiroshi

    2017-07-01

    Non-invasive identification of ischemic regions is important for diagnosis and treatment of myocardial infarction. In the present study, ultrasound measurement was applied to the interventricular septum of three open-chest swine hearts. The properties of the myocardial contraction response of the septum were compared between normal and acute ischemic conditions, where the acute ischemic condition of the septum originated from direct avascularization of the left anterior descending (LAD) coronary artery. The result showed that the contraction response propagated from the basal side to the apical side along the septum. The estimated propagation velocities in the normal and acute ischemic conditions were 3.6 and 1.9 m/s, respectively. This finding indicates that acute ischemia which occurred 5 s after the avascularization of the LAD promptly suppressed the propagation velocity through the ventricular septum to about half the normal velocity. It was suggested that the myocardial ischemic region could be identified using the difference in the propagation velocity of the myocardial response to contraction.

  17. 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...

  18. Invasive or non-invasive imaging for detecting high-risk coronary lesions?

    NARCIS (Netherlands)

    K. Patel (Kush); J. Tarkin (Jason); P.W.J.C. Serruys (Patrick); E. Tenekecioglu (Erhan); N. Foin (Nicolas); Y. Zhang (Yaojun); T. Crake (Tom); J. Moon (James); A. Mathur (Anthony); C.V. Bourantas (Christos)

    2017-01-01

    markdownabstract_Introduction:_ Advances in our understanding about atherosclerotic evolution have enabled us to identify specific plaque characteristics that are associated with coronary plaque vulnerability and cardiovascular events. With constant improvements in signal and image processing an

  19. 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

  20. Magnetic resonance imaging based functional imaging in paediatric oncology.

    Science.gov (United States)

    Manias, Karen A; Gill, Simrandip K; MacPherson, Lesley; Foster, Katharine; Oates, Adam; Peet, Andrew C

    2017-02-01

    Imaging is central to management of solid tumours in children. Conventional magnetic resonance imaging (MRI) is the standard imaging modality for tumours of the central nervous system (CNS) and limbs and is increasingly used in the abdomen. It provides excellent structural detail, but imparts limited information about tumour type, aggressiveness, metastatic potential or early treatment response. MRI based functional imaging techniques, such as magnetic resonance spectroscopy, diffusion and perfusion weighted imaging, probe tissue properties to provide clinically important information about metabolites, structure and blood flow. This review describes the role of and evidence behind these functional imaging techniques in paediatric oncology and implications for integrating them into routine clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. 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.

  2. [Applicability of non-invasive imaging methods in forensic medicine and forensic anthropology in particular].

    Science.gov (United States)

    Marcinková, Mária; Straka, Ľubomír; Novomeský, František; Janík, Martin; Štuller, František; Krajčovič, Jozef

    2018-01-01

    Massive progress in developing even more precise imaging modalities influenced all medical branches including the forensic medicine. In forensic anthropology, an inevitable part of forensic medicine itself, the use of all imaging modalities becomes even more important. Despite of acquiring more accurate informations about the deceased, all of them can be used in the process of identification and/or age estimation. X - ray imaging is most commonly used in detecting foreign bodies or various pathological changes of the deceased. Computed tomography, on the other hand, can be very helpful in the process of identification, whereas outcomes of this examination can be used for virtual reconstruction of living objects. Magnetic resonance imaging offers new opportunities in detecting cardiovascular pathological processes or develompental anomalies. Ultrasonography provides promising results in age estimation of living subjects without excessive doses of radiation. Processing the latest information sources available, authors introduce the application examples of X - ray imaging, computed tomography, magnetic resonance imaging and ultrasonography in everyday forensic medicine routine, with particular focusing on forensic anthropology.

  3. 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.

  4. Resting-state functional connectivity imaging of the mouse brain using photoacoustic tomography

    Science.gov (United States)

    Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Q.; Culver, Joseph P.; Wang, Lihong V.

    2014-03-01

    Resting-state functional connectivity (RSFC) imaging is an emerging neuroimaging approach that aims to identify spontaneous cerebral hemodynamic fluctuations and their associated functional connections. Clinical studies have demonstrated that RSFC is altered in brain disorders such as stroke, Alzheimer's, autism, and epilepsy. However, conventional neuroimaging modalities cannot easily be applied to mice, the most widely used model species for human brain disease studies. For instance, functional magnetic resonance imaging (fMRI) of mice requires a very high magnetic field to obtain a sufficient signal-to-noise ratio and spatial resolution. Functional connectivity mapping with optical intrinsic signal imaging (fcOIS) is an alternative method. Due to the diffusion of light in tissue, the spatial resolution of fcOIS is limited, and experiments have been performed using an exposed skull preparation. In this study, we show for the first time, the use of photoacoustic computed tomography (PACT) to noninvasively image resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight regions, as well as several subregions. These findings agreed well with the Paxinos mouse brain atlas. This study showed that PACT is a promising, non-invasive modality for small-animal functional brain imaging.

  5. Non invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognative Functions

    Science.gov (United States)

    2017-05-14

    neuropsychological tests: cognitive performance, perceptual reasoning, working memory , processing speed and perceived stress scale were performed. Brain...AFRL-AFOSR-JP-TR-2017-0052 Non-invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognative Functions...invasive Imaging based Detection and Mapping of Brain Oxidative Stress and its Correlation with Cognative Functions 5a.  CONTRACT NUMBER 5b.  GRANT

  6. 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

  7. 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

    International Nuclear Information System (INIS)

    Rivard, MJ; Ghadyani, HR; Bastien, AD; Lutz, NN; Hepel, JT

    2015-01-01

    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

  8. Non-invasive quantification of pancreatic exocrine function using secretin-stimulated MRCP

    International Nuclear Information System (INIS)

    Punwani, S.; Gillams, A.R.; Lees, W.R.

    2003-01-01

    Our objective was to quantify water volume using magnetic resonance cholangiopancreatography (MRCP) sequences and apply this to secretin-stimulated studies with the aim of quantifying pancreatic exocrine function. A commercially available single-shot MRCP sequence was used in conjunction with a body phased-array coil and a 1.5-T MR system. Signal intensity was measured in samples of water, pancreatic, duodenal juice, and secretin-stimulated pancreatic juice. A water phantom was made and MR calculated volumes compared with known water volumes within the phantom. Changes in small intestinal volume in response to secretin were measured in a group of 11 patients with no evidence of pancreatic disease. Changes in water volume were plotted over time. The pancreatic duct diameter before and after secretin was noted and filling defects were sought. All patients also underwent an axial breath-hold T1-weighted gradient-echo sequence and the pancreatic parenchyma was evaluated for size and signal intensity. There was no difference in the signal intensity of the different juice samples. There was excellent correlation between known and calculated MRCP volumes (χ 2 =0.99). All patients demonstrated normal duct morphology on MRCP and normal pancreatic parenchyma on T1-weighted imaging. The mean flow rate in the patient population was 8.1±2.5 ml/s over a median of 7 min (range 5-9 min). The MRCP sequence can be used to measure water volume. Sequential MRCP measurements following secretin permitted calculation of volume change and flow rate. This should prove useful as an indicator of pancreatic exocrine function. (orig.)

  9. 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

  10. Visualisation of non-invasive coronary bypass imaging: 4-row vs. 16-row multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M. Fawad; Herzog, Christopher; Landenberger, Kai; Maataoui, Adel; Vogl, Thomas J. [Johann Wolfgang Goethe University, Institute for Diagnostic and Interventional Radiology, Frankfurt/Main (Germany); Martens, Sven; Moritz, Anton [Johann Wolfgang Goethe University, Department for Thoracic and Cardiovascular Surgery, Frankfurt/Main (Germany); Ackermann, Hanns [Johann Wolfgang Goethe University, Institute for Epidemilogy and Medical Statistics, Frankfurt/Main (Germany)

    2005-01-01

    The purpose of this study was to investigate the image quality of coronary artery bypass graft visualization in 4- and 16-row multidetector CT using multiple imaging reformations. Material and Methods:One hundred sixteen patients underwent CT examination of the heart after receiving CABG. Group A (n=58) received 4-row MDCT; group B (n=58) received 16-row MDCT. Various bypass types such as LITA to LAD and venous grafts to the RCA and RCX were included in the study. A five-point Likert scale was used to grade image quality. Each bypass was reviewed under different imaging reformations: thin slap maximum intensity projection (MIP thin), multiplanar reformation (MPR) and volume rendering technique (VRT). Special attention was paid to the delineation of the distal anastomosis. Interobserver correlation was determined. From 289 bypass grafts examined, 279 (96.54%) were classified as patent and 10 (3.46%) as not patent. Except for the distal anastomosis, 16-row MDCT showed significantly better results for all segments of bypasses. Comparison of reformations within group A and B showed that MIP thin (P<0.05) and VRT (P<0.05) displayed better visualization as compared to MPR. Significantly better imaging of all bypass types is possible using 16-row MDCT as compared to 4-row MDCT. Assessment of the distal anastomosis yields no difference between 4- and 16-row technology. (orig.)

  11. [Functional and molecular imaging of breast tumors].

    Science.gov (United States)

    Pinker, K; Brader, P; Karanikas, G; El-Rabadi, K; Bogner, W; Gruber, S; Reisegger, M; Trattnig, S; Helbich, T H

    2010-11-01

    Molecular imaging is concerned with the presentation, description and quantification of biological and physiological processes at the cellular and molecular level. Most recently molecular imaging has started to become established in breast diagnostics. This review article will give an overview of procedures which are either in the preclinical development stage or which have already become clinically established. Molecular nuclear medicine breast imaging (breast-specific gamma imaging [BSGI] and positron emission mammography [PEM]) together with specific radiotracers and contrast media will be discussed. The possibilities for magnetic resonance imaging in functional (DWI) and metabolic (MRSI) imaging of breast lesions and the combined application of nuclear medicine and magnetic resonance imaging (PET/MRI) will be explained. Furthermore, an overview on the preclinical procedure and the possible clinical applications of optical and photoacoustic imaging will be given.

  12. Noninvasive, low-noise, fast imaging of blood volume and deoxygenation changes in muscles using light-emitting diode continuous-wave imager

    Science.gov (United States)

    Lin, Yuanqing; Lech, Gwen; Nioka, Shoko; Intes, Xavier; Chance, Britton

    2002-08-01

    This article focuses on optimizing the signal to noise ratio (SNR) of a three-wavelength light-emitting diode (LED) near-infrared continuous-wave (cw) imager and its application to in vivo muscle metabolism measurement. The shot-noise limited SNR is derived and calculated to be 2 x104 for the physiological blood concentrations of muscle. Aiming at shot-noise limited SNR performance and fast imaging, we utilize sample and hold circuits to reduce high-frequency noise. These circuits have also been designed to be parallel integrating, through which SNR of 2 x103 and 2 Hz imaging acquisition rate have been achieved when the probe is placed on a muscle model. The noise corresponds to 2 x10-4 optical density error, which suggests an in vitro resolution of 15. 4 nM blood volume and 46.8 nM deoxygenation changes. A 48 dB digital gain control circuit with 256 steps is employed to enlarge the dynamic range of the imager. We utilize cuff ischemia as a living model demonstration and its results are reported. The instrument is applied during exercise to measure the changes of blood volume and deoxygenation, which provides important information about muscle metabolism. We find that the primary source of noise encountered during exercise experiment is from the random motion of muscle. The results demonstrate that the LED cw imager is ideal for the noninvasive study of muscle metabolism.

  13. A fast analysis method for non-invasive imaging of blood flow in individual cerebral arteries using vessel-encoded arterial spin labelling angiography

    OpenAIRE

    Chappell, Michael A.; Okell, Thomas W.; Payne, Stephen J.; Jezzard, Peter; Woolrich, Mark W.

    2012-01-01

    Arterial spin labelling (ASL) MRI offers a non-invasive means to create blood-borne contrast in vivo for dynamic angiographic imaging. By spatial modulation of the ASL process it is possible to uniquely label individual arteries over a series of measurements, allowing each to be separately identified in the resulting angiographic images. This separation requires appropriate analysis for which a general Bayesian framework has previously been proposed. Here this framework is adapted for clinica...

  14. Non-Invasive Magnetic Resonance Imaging of Nanoparticle Migration and Water Velocity Inside Sandstone

    Science.gov (United States)

    Phoenix, V. R.; Shukla, M.; Vallatos, A.; Riley, M. S.; Tellam, J. H.; Holmes, W. M.

    2015-12-01

    Manufactured nanoparticles (NPs) are already utilized in a diverse array of applications, including cosmetics, optics, medical technology, textiles and catalysts. Problematically, once in the natural environment, NPs can have a wide range of toxic effects. To protect groundwater from detrimental NPs we must be able to predict nanoparticle movement within the aquifer. The often complex transport behavior of nanoparticles ensures the development of NP transport models is not a simple task. To enhance our understanding of NP transport processes, we utilize novel magnetic resonance imaging (MRI) which enables us to look inside the rock and image the movement of nanoparticles within. For this, we use nanoparticles that are paramagnetic, making them visible to the MRI and enabling us to collect spatially resolved data from which we can develop more robust transport models. In this work, a core of Bentheimer sandstone (3 x 7 cm) was saturated with water and imaged inside a 7Tesla Bruker Biospec MRI. Firstly the porosity of the core was mapped using a MSME MRI sequence. Prior to imaging NP transport, the velocity of water (in absence on nanoparticles) was mapped using an APGSTE-RARE sequence. Nano-magnetite nanoparticles were then pumped into the core and their transport through the core was imaged using a RARE sequence. These images were calibrated using T2 parameter maps to provide fully quantitative maps of nanoparticle concentration at regular time intervals throughout the column (T2 being the spin-spin relaxation time of 1H nuclei). This work demonstrated we are able to spatially resolve porosity, water velocity and nanoparticle movement, inside rock, using a single technique (MRI). Significantly, this provides us with a unique and powerful dataset from which we are now developing new models of nanoparticle transport.

  15. Irbesartan Attenuates Atherosclerosis in Watanabe Heritable Hyperlipidemic Rabbits: Noninvasive Imaging of Inflammation by 18F-Fluorodeoxyglucose Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2015-05-01

    Full Text Available The purpose of this study was to assess the usefulness of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET in evaluating the antiatherogenic effects of irbesartan, an angiotensin II type 1 receptor blocker. Watanabe heritable hyperlipidemic rabbits were divided into the irbesartan-treated group (75 mg/kg/d; n = 14 and the control group (n = 14. After a 9-month treatment, rabbits underwent 18F-FDG PET. Using the aortic lesions, autoradiography and histologic examinations were performed. PET imaging clearly visualized the thoracic lesions of control rabbits and showed a significant decrease in the 18F-FDG uptake level of irbesartan-treated rabbits (78.8% of controls; p < .05. Irbesartan treatment significantly reduced the plaque size (43.1% of controls and intraplaque macrophage infiltration level (48.1% of controls. The 18F-FDG uptake level in plaques positively correlated with the plaque size (r = .65, p < .05 and macrophage infiltration level (r = .57, p < .05. Noninvasive imaging by 18F-FDG PET is useful for evaluating the therapeutic effects of irbesartan and reflects inflammation, a key factor involved in the therapeutic effects.

  16. Noninvasive detection of hepatic lipidosis in dairy cows with calibrated ultrasonographic image analysis.

    NARCIS (Netherlands)

    Starke, A.; Haudum, A.; Weijers, G.; Herzog, K.; Wohlsein, P.; Beyerbach, M.; Korte, C.L. de; Thijssen, J.M.; Rehage, J.

    2010-01-01

    The aim was to test the accuracy of calibrated digital analysis of ultrasonographic hepatic images for diagnosing fatty liver in dairy cows. Digital analysis was performed by means of a novel method, computer-aided ultrasound diagnosis (CAUS), previously published by the authors. This method implies

  17. 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

  18. 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.

  19. Functional imaging of the human placenta with magnetic resonance.

    Science.gov (United States)

    Siauve, Nathalie; Chalouhi, Gihad E; Deloison, Benjamin; Alison, Marianne; Clement, Olivier; Ville, Yves; Salomon, Laurent J

    2015-10-01

    Abnormal placentation is responsible for most failures in pregnancy; however, an understanding of placental functions remains largely concealed from noninvasive, in vivo investigations. Magnetic resonance imaging (MRI) is safe in pregnancy for magnetic fields of up to 3 Tesla and is being used increasingly to improve the accuracy of prenatal imaging. Functional MRI (fMRI) of the placenta has not yet been validated in a clinical setting, and most data are derived from animal studies. FMRI could be used to further explore placental functions that are related to vascularization, oxygenation, and metabolism in human pregnancies by the use of various enhancement processes. Dynamic contrast-enhanced MRI is best able to quantify placental perfusion, permeability, and blood volume fractions. However, the transplacental passage of Gadolinium-based contrast agents represents a significant safety concern for this procedure in humans. There are alternative contrast agents that may be safer in pregnancy or that do not cross the placenta. Arterial spin labeling MRI relies on magnetically labeled water to quantify the blood flows within the placenta. A disadvantage of this technique is a poorer signal-to-noise ratio. Based on arterial spin labeling, placental perfusion in normal pregnancy is 176 ± 91 mL × min(-1) × 100 g(-1) and decreases in cases with intrauterine growth restriction. Blood oxygen level-dependent and oxygen-enhanced MRIs do not assess perfusion but measure the response of the placenta to changes in oxygen levels with the use of hemoglobin as an endogenous contrast agent. Diffusion-weighted imaging and intravoxel incoherent motion MRI do not require exogenous contrast agents, instead they use the movement of water molecules within tissues. The apparent diffusion coefficient and perfusion fraction are significantly lower in placentas of growth-restricted fetuses when compared with normal pregnancies. Magnetic resonance spectroscopy has the ability to extract

  20. 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.

  1. Noninvasive determination of language dominance using functional MRI and near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Ota, Takahiro; Kamada, Kyousuke; Saito, Nobuhito

    2009-01-01

    Identification of the language dominant hemisphere is important in cases necessary for partial encephalotomy due to epilepsy and tumor. Functional MRI (fMRI) essentially detects oxy-Hb/deoxy-Hb ratio in the brain region resulted from blood flow change and near-infrared spectroscopy (NIRS), the Hb level change in the tissue, in which the image can be detected by light-receiving proves of NIR-light (780-1500 nm wavelength) irradiated and passed through the tissues. This paper describes the comparison of the two methods for determination of language dominance with reference to that identified by Wada test, a gold standard but inconvenient for both operators and patients. Subjects are 11 brain tumor and 11 epilepsy patients (M 10/F 12, av. age of 36.7 y, 19 right-handed), whose dominances are successfully determined previously by Wada test. fMRI is conducted with 3T machine (General Electric, USA) with phased-array coil in patients receiving various language tasks, and data are processed by Dr. View (Asahi Kasei) to calculate the laterality index for the dominance. NIRS is conducted with Hitachi-Medico ETG-4000 with 695 and 830 nm IR in patients receiving other different language tasks, on whose frontotemporal region of head surface 12-channel probes are equipped. Data are processed by the equipped software to calculate the difference of oxy-Hb change rates between the two hemispheres for the dominance determination. Consistency of fMRI in determining the dominance with Wada test is found 86.3% and of NIRS, 72.7%, which suggests the latter can be only supplementary to the former. However, NIRS is noted to be useful in atypical cases like those with right or bilateral dominance. (K.T.)

  2. Tutte polynomial in functional magnetic resonance imaging

    Science.gov (United States)

    García-Castillón, Marlly V.

    2015-09-01

    Methods of graph theory are applied to the processing of functional magnetic resonance images. Specifically the Tutte polynomial is used to analyze such kind of images. Functional Magnetic Resonance Imaging provide us connectivity networks in the brain which are represented by graphs and the Tutte polynomial will be applied. The problem of computing the Tutte polynomial for a given graph is #P-hard even for planar graphs. For a practical application the maple packages "GraphTheory" and "SpecialGraphs" will be used. We will consider certain diagram which is depicting functional connectivity, specifically between frontal and posterior areas, in autism during an inferential text comprehension task. The Tutte polynomial for the resulting neural networks will be computed and some numerical invariants for such network will be obtained. Our results show that the Tutte polynomial is a powerful tool to analyze and characterize the networks obtained from functional magnetic resonance imaging.

  3. In vivo hepatocyte MR imaging using lactose functionalized magnetoliposomes.

    Science.gov (United States)

    Ketkar-Atre, Ashwini; Struys, Tom; Dresselaers, Tom; Hodenius, Michael; Mannaerts, Inge; Ni, Yicheng; Lambrichts, Ivo; Van Grunsven, Leo A; De Cuyper, Marcel; Himmelreich, Uwe

    2014-01-01

    The aim of this study was to assess a novel lactose functionalized magnetoliposomes (MLs) as an MR contrast agent to target hepatocytes as well as to evaluate the targeting ability of MLs for in vivo applications. In the present work, 17 nm sized iron oxide cores functionalized with anionic MLs bearing lactose moieties were used for targeting the asialoglycoprotein receptor (ASGP-r), which is highly expressed in hepatocytes. Non-functionalized anionic MLs were tested as negative controls. The size distribution of lactose and anionic MLs was determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). After intravenous administration of both MLs, contrast enhancement in the liver was observed by magnetic resonance imaging (MRI). Label retention was monitored non-invasively by MRI and validated with Prussian blue staining and TEM for up to eight days post MLs administration. Although the MRI signal intensity did not show significant differences between functionalized and non-functionalized particles, iron-specific Prussian blue staining and TEM analysis confirmed the uptake of lactose MLs mainly in hepatocytes. In contrast, non-functionalized anionic MLs were mainly taken up by Kupffer and sinusoidal cells. Target specificity was further confirmed by high-resolution MR imaging of phantoms containing isolated hepatocytes, Kupffer cell (KCs) and hepatic stellate cells (HSCs) fractions. Hypointense signal was observed for hepatocytes isolated from animals which received lactose MLs but not from animals which received anionic MLs. These data demonstrate that galactose-functionalized MLs can be used as a hepatocyte targeting MR contrast agent to potentially aid in the diagnosis of hepatic diseases if the non-specific uptake by KCs is taken into account. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Noninvasive spectral imaging of skin chromophores based on multiple regression analysis aided by Monte Carlo simulation

    Science.gov (United States)

    Nishidate, Izumi; Wiswadarma, Aditya; Hase, Yota; Tanaka, Noriyuki; Maeda, Takaaki; Niizeki, Kyuichi; Aizu, Yoshihisa

    2011-08-01

    In order to visualize melanin and blood concentrations and oxygen saturation in human skin tissue, a simple imaging technique based on multispectral diffuse reflectance images acquired at six wavelengths (500, 520, 540, 560, 580 and 600nm) was developed. The technique utilizes multiple regression analysis aided by Monte Carlo simulation for diffuse reflectance spectra. Using the absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are deduced numerically in advance, while oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments with human skin of the human hand during upper limb occlusion and of the inner forearm exposed to UV irradiation demonstrated the ability of the method to evaluate physiological reactions of human skin tissue.

  5. Non-invasive assessment of pulsatile intracranial pressure with phase-contrast magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Geir Ringstad

    Full Text Available Invasive monitoring of pulsatile intracranial pressure can accurately predict shunt response in patients with idiopathic normal pressure hydrocephalus, but may potentially cause complications such as bleeding and infection. We tested how a proposed surrogate parameter for pulsatile intracranial pressure, the phase-contrast magnetic resonance imaging derived pulse pressure gradient, compared with its invasive counterpart. In 22 patients with suspected idiopathic normal pressure hydrocephalus, preceding invasive intracranial pressure monitoring, and any surgical shunt procedure, we calculated the pulse pressure gradient from phase-contrast magnetic resonance imaging derived cerebrospinal fluid flow velocities obtained at the upper cervical spinal canal using a simplified Navier-Stokes equation. Repeated measurements of the pulse pressure gradient were also undertaken in four healthy controls. Of 17 shunted patients, 16 responded, indicating high proportion of "true" normal pressure hydrocephalus in the patient cohort. However, there was no correlation between the magnetic resonance imaging derived pulse pressure gradient and pulsatile intracranial pressure (R = -.18, P = .43. Pulse pressure gradients were also similar in patients and healthy controls (P = .26, and did not differ between individuals with pulsatile intracranial pressure above or below established thresholds for shunt treatment (P = .97. Assessment of pulse pressure gradient at level C2 was therefore not found feasible to replace invasive monitoring of pulsatile intracranial pressure in selection of patients with idiopathic normal pressure hydrocephalus for surgical shunting. Unlike invasive, overnight monitoring, the pulse pressure gradient from magnetic resonance imaging comprises short-term pressure fluctuations only. Moreover, complexity of cervical cerebrospinal fluid flow and -pulsatility at the upper cervical spinal canal may render the pulse pressure gradient a poor surrogate

  6. Noninvasive imaging of human skin hemodynamics using a digital red-green-blue camera

    Science.gov (United States)

    Nishidate, Izumi; Tanaka, Noriyuki; Kawase, Tatsuya; Maeda, Takaaki; Yuasa, Tomonori; Aizu, Yoshihisa; Yuasa, Tetsuya; Niizeki, Kyuichi

    2011-08-01

    In order to visualize human skin hemodynamics, we investigated a method that is specifically developed for the visualization of concentrations of oxygenated blood, deoxygenated blood, and melanin in skin tissue from digital RGB color images. Images of total blood concentration and oxygen saturation can also be reconstructed from the results of oxygenated and deoxygenated blood. Experiments using tissue-like agar gel phantoms demonstrated the ability of the developed method to quantitatively visualize the transition from an oxygenated blood to a deoxygenated blood in dermis. In vivo imaging of the chromophore concentrations and tissue oxygen saturation in the skin of the human hand are performed for 14 subjects during upper limb occlusion at 50 and 250 mm Hg. The response of the total blood concentration in the skin acquired by this method and forearm volume changes obtained from the conventional strain-gauge plethysmograph were comparable during the upper arm occlusion at pressures of both 50 and 250 mm Hg. The results presented in the present paper indicate the possibility of visualizing the hemodynamics of subsurface skin tissue.

  7. Noninvasive imaging of multiple myeloma using near infrared fluorescent molecular probe

    Science.gov (United States)

    Hathi, Deep; Zhou, Haiying; Bollerman-Nowlis, Alex; Shokeen, Monica; Akers, Walter J.

    2016-03-01

    Multiple myeloma is a plasma cell malignancy characterized by monoclonal gammopathy and osteolytic bone lesions. Multiple myeloma is most commonly diagnosed in late disease stages, presenting with pathologic fracture. Early diagnosis and monitoring of disease status may improve quality of life and long-term survival for multiple myeloma patients from what is now a devastating and fatal disease. We have developed a near-infrared targeted fluorescent molecular probe with high affinity to the α4β1 integrin receptor (VLA-4)overexpressed by a majority of multiple myeloma cells as a non-radioactive analog to PET/CT tracer currently being developed for human diagnostics. A near-infrared dye that emits about 700 nm was conjugated to a high affinity peptidomimmetic. Binding affinity and specificity for multiple myeloma cells was investigated in vitro by tissue staining and flow cytometry. After demonstration of sensitivity and specificity, preclinical optical imaging studies were performed to evaluate tumor specificity in murine subcutaneous and metastatic multiple myeloma models. The VLA-4-targeted molecular probe showed high affinity for subcutaneous MM tumor xenografts. Importantly, tumor cells specific accumulation in the bone marrow of metastatic multiple myeloma correlated with GFP signal from transfected cells. Ex vivo flow cytometry of tumor tissue and bone marrow further corroborated in vivo imaging data, demonstrating the specificity of the novel agent and potential for quantitative imaging of multiple myeloma burden in these models.

  8. Imaging regional renal function parameters using radionuclide tracers

    Science.gov (United States)

    Qiao, Yi

    A compartmental model is given for evaluating kidney function accurately and noninvasively. This model is cast into a parallel multi-compartment structure and each pixel region (picture element) of kidneys is considered as a single kidney compartment. The loss of radionuclide tracers from the blood to the kidney and from the kidney to the bladder are modelled in great detail. Both the uptake function and the excretion function of the kidneys can be evaluated pixel by pixel, and regional diagnostic information on renal function is obtained. Gamma Camera image data are required by this model and a screening test based renal function measurement is provided. The regional blood background is subtracted from the kidney region of interest (ROI) and the kidney regional rate constants are estimated analytically using the Kuhn-Pucker multiplier method in convex programming by considering the input/output behavior of the kidney compartments. The detailed physiological model of the peripheral compartments of the system, which is not available for most radionuclide tracers, is not required in the determination of the kidney regional rate constants and the regional blood background factors within the kidney ROI. Moreover, the statistical significance of measurements is considered to assure the improved statistical properties of the estimated kidney rate constants. The relations between various renal function parameters and the kidney rate constants are established. Multiple renal function measurements can be found from the renal compartmental model. The blood radioactivity curve and the regional (or total) radiorenogram determining the regional (or total) summed behavior of the kidneys are obtained analytically with the consideration of the statistical significance of measurements using convex programming methods for a single peripheral compartment system. In addition, a new technique for the determination of 'initial conditions' in both the blood compartment and the kidney

  9. Long-termserial non-invasive multislice computed tomography angiography with functional evaluation after coronary implantation of a bioresorbable everolimus-eluting scaffold: the ABSORB cohort BMSCT substudy

    NARCIS (Netherlands)

    Onuma, Yoshinobu; Collet, Carlos; van Geuns, Robert-Jan; de Bruyne, Bernard; Christiansen, Evald; Koolen, Jacques; Smits, Pieter; Chevalier, Bernard; McClean, Dougal; Dudek, Dariusz; Windecker, Stephan; Meredith, Ian; Nieman, Koen; Veldhof, Susan; Ormiston, John; Serruys, Patrick W.

    2017-01-01

    Aims Multimodality invasive imaging of the first-in-man cohort demonstrated at 5 years stable lumen dimensions and a low rate of major adverse cardiac events (MACE). However, the long-term non-invasive assessment of this device remains to be documented. The objective was to describe the 72-month

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

    Science.gov (United States)

    2015-12-01

    biologic effect of radiation treatment, rather than just the physical dose1-6. The first-year research goals were to develop the imaging instrumentation to...this modality is significant to tracking the biologic effect of radiation treatment, rather than just the physical dose1-6. The first-year research...the photoacoustic signal and performing ultrasound pulse-echo imaging8. 4 Figure 1 (a) Schematic of trans-urethral photoacoustic (TUPA) system

  11. 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

  12. A red fluorescent nude mouse model of human endometriosis: advantages of a non-invasive imaging method.

    Science.gov (United States)

    Wang, Ningning; Hong, Shanshan; Tan, Jinfeng; Ke, Peiqi; Liang, Lili; Fei, Hui; Liu, Bin; Liu, Liqun; Liu, Yongdong; Yu, Bingjun

    2014-05-01

    To establish red fluorescent human endometriosis lesions in a nude mouse model and dynamically and non-invasively to compare intraperitoneal and subcutaneous injection models. Primary cultures of endometrial stromal cells (ESCs) and epithelial cells (EECs) isolated from 24 patients with a normal uterine cavity were transfected with 2.5×10(8) (Group 1) and 1.25×10(8) (Group 2) plaque-forming units (PFU) of adenovirus encoding red fluorescent protein (Ad-RFP). Transfection efficiencies, fluorescence intensity and apoptosis rate of the two types of cells were compared in vitro. A mixture of 2.5×10(8) PFU Ad-RFP-infected approximately 400 EECs cell mass and 2×10(6) ESCs for 36h was injected individually into 24 female nude mice subcutaneously (Group A) or intraperitoneally (Group B). From Day 5 after injection, an in vivo imaging system (IVIS) was used to non-invasively observe and compare the lesions of the two groups every week until Day 33. Specifically, the fluorescent intensity, positive rates, persistence time and lesion weight in the implanted human endometriosis lesions were compared. A parametric Student's t-test and two-way analysis of variance were used for statistical analysis. Compared with 1.25×10(8) PFU RFP, a titre of 2.5×10(8) PFU RFP ESCs and EECs incubated for 36h exhibited higher transfection efficiencies and higher fluorescence intensities in vitro. In vivo imaging of the fluorescent human endometriosis lesions originating from an RFP titre of 2.5×10(8) PFU showed that the intensity and lesion weight in Group A were significantly higher than in Group B. However, the two groups had the same RFP-positive rates and fluorescence persistence. The structure of each lesion was evaluated by immunohistochemistry to confirm its human endometrial origin. The red fluorescent human endometriosis model established by subcutaneously injecting 2.5×10(8) PFU RFP-transfected stromal cells and epithelial cells into nude mice had a higher fluorescent positive

  13. Pulmonary functional MR imaging for COPD

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu

    2008-01-01

    Chronic obstructive pulmonary disease (COPD) is a slowly progressive disease characterized by airflow limitation, cough, sputum production, and, at later stages, dyspnea. COPD is currently the fourth-leading cause of mortality and the twelfth-leading cause of disability, and by the year 2020 it is expected to be the third-leading cause of death and the fifth-leading cause of disability worldwide. The diagnosis of COPD largely relies on a history of exposure to noxious stimuli and abnormal lung function test results. Since the pathology of COPD varies and the molecular mechanisms are only slightly understood, the diagnosis and stage assessment of COPD have relied on the results of pulmonary function test. In addition, CT and nuclear medicine study are utilized for assessment of regional morphological and functional abnormalities. Recently, pulmonary functional MR imaging is suggested as a new technique for assessment of regional physiopathologic information in various pulmonary diseases including COPD, pulmonary thromboembolism, lung cancer and interstitial lung diseases. This review article covers the brief description of theory and clinical application of contrast-enhanced perfusion MR imaging; hyperpolarized noble gas MR imaging and oxygen-enhanced MR imaging in COPD subjects. We believe that further basic studies as well as clinical applications of this new technique will define the real significance of pulmonary functional MR imaging for the future of pulmonary functional imaging and its usefulness for diagnosis and patients' management in COPD. (author)

  14. Subband/transform functions for image processing

    Science.gov (United States)

    Glover, Daniel

    1993-01-01

    Functions for image data processing written for use with the MATLAB(TM) software package are presented. These functions provide the capability to transform image data with block transformations (such as the Walsh Hadamard) and to produce spatial frequency subbands of the transformed data. Block transforms are equivalent to simple subband systems. The transform coefficients are reordered using a simple permutation to give subbands. The low frequency subband is a low resolution version of the original image, while the higher frequency subbands contain edge information. The transform functions can be cascaded to provide further decomposition into more subbands. If the cascade is applied to all four of the first stage subbands (in the case of a four band decomposition), then a uniform structure of sixteen bands is obtained. If the cascade is applied only to the low frequency subband, an octave structure of seven bands results. Functions for the inverse transforms are also given. These functions can be used for image data compression systems. The transforms do not in themselves produce data compression, but prepare the data for quantization and compression. Sample quantization functions for subbands are also given. A typical compression approach is to subband the image data, quantize it, then use statistical coding (e.g., run-length coding followed by Huffman coding) for compression. Contour plots of image data and subbanded data are shown.

  15. 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. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  16. 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.

  17. Comparison between non-invasive methods used on paintings by Goya and his contemporaries: hyperspectral imaging vs. point-by-point spectroscopic analysis.

    Science.gov (United States)

    Daniel, Floréal; Mounier, Aurélie; Pérez-Arantegui, Josefina; Pardos, Carlos; Prieto-Taboada, Nagore; Fdez-Ortiz de Vallejuelo, Silvia; Castro, Kepa

    2017-06-01

    The development of non-invasive techniques for the characterization of pigments is crucial in order to preserve the integrity of the artwork. In this sense, the usefulness of hyperspectral imaging was demonstrated. It allows pigment characterization of the whole painting. However, it also sometimes requires the complementation of other point-by-point techniques. In the present article, the advantages of hyperspectral imaging over point-by-point spectroscopic analysis were evaluated. For that purpose, three paintings were analysed by hyperspectral imaging, handheld X-ray fluorescence and handheld Raman spectroscopy in order to determine the best non-invasive technique for pigment identifications. Thanks to this work, the main pigments used in Aragonese artworks, and especially in Goya's paintings, were identified and mapped by imaging reflection spectroscopy. All the analysed pigments corresponded to those used at the time of Goya. Regarding the techniques used, the information obtained by the hyperspectral imaging and point-by-point analysis has been, in general, different and complementary. Given this fact, selecting only one technique is not recommended, and the present work demonstrates the usefulness of the combination of all the techniques used as the best non-invasive methodology for the pigments' characterization. Moreover, the proposed methodology is a relatively quick procedure that allows a larger number of Goya's paintings in the museum to be surveyed, increasing the possibility of obtaining significant results and providing a chance for extensive comparisons, which are relevant from the point of view of art history issues.

  18. Peak negative myocardial velocity gradient in early diastole as a noninvasive indicator of left ventricular diastolic function: comparison with transmitral flow velocity indices.

    Science.gov (United States)

    Shimizu, Y; Uematsu, M; Shimizu, H; Nakamura, K; Yamagishi, M; Miyatake, K

    1998-11-01

    We sought to assess the clinical significance of peak negative myocardial velocity gradient (MVG) in early diastole as a noninvasive indicator of left ventricular (LV) diastolic function. Peak systolic MVG has been shown useful for the quantitative assessment of regional wall motion abnormalities, but limited data exist regarding the diastolic MVG as an indicator of LV diastolic function. Peak negative MVG was obtained from M-mode tissue Doppler imaging (TDI) in 43 subjects with or without impairment of systolic and diastolic performance: 12 normal subjects, 12 patients with hypertensive heart disease (HHD) with normal systolic performance and 19 patients with dilated cardiomyopathy (DCM), and was compared with standard Doppler transmitral flow velocity indices. In a subgroup of 30 patients, effects of preload increase on these indices were assessed by performing passive leg lifting. In an additional 11 patients with congestive heart failure at the initial examination, the measurements were repeated after 26+/-16 days of volume-reducing therapy. Peak negative MVG was significantly depressed both in HHD (-3.9+/-1.3/s, p indices failed to distinguish DCM from normal due to the pseudonormalization. Transmitral flow velocity indices were significantly altered (peak early/late diastolic filling velocity [E/A]=1.1+/-0.5 to 1.5+/-0.7, p indicator of LV diastolic function that is less affected by preload alterations than the transmitral flow velocity indices, and thereby could be used for the follow-up of patients with nonischemic LV dysfunction presenting congestive heart failure.

  19. Noninvasive quantification of cerebral metabolic rate for glucose in rats using (18)F-FDG PET and standard input function.

    Science.gov (United States)

    Hori, Yuki; Ihara, Naoki; Teramoto, Noboru; Kunimi, Masako; Honda, Manabu; Kato, Koichi; Hanakawa, Takashi

    2015-10-01

    Measurement of arterial input function (AIF) for quantitative positron emission tomography (PET) studies is technically challenging. The present study aimed to develop a method based on a standard arterial input function (SIF) to estimate input function without blood sampling. We performed (18)F-fluolodeoxyglucose studies accompanied by continuous blood sampling for measurement of AIF in 11 rats. Standard arterial input function was calculated by averaging AIFs from eight anesthetized rats, after normalization with body mass (BM) and injected dose (ID). Then, the individual input function was estimated using two types of SIF: (1) SIF calibrated by the individual's BM and ID (estimated individual input function, EIF(NS)) and (2) SIF calibrated by a single blood sampling as proposed previously (EIF(1S)). No significant differences in area under the curve (AUC) or cerebral metabolic rate for glucose (CMRGlc) were found across the AIF-, EIF(NS)-, and EIF(1S)-based methods using repeated measures analysis of variance. In the correlation analysis, AUC or CMRGlc derived from EIF(NS) was highly correlated with those derived from AIF and EIF(1S). Preliminary comparison between AIF and EIF(NS) in three awake rats supported an idea that the method might be applicable to behaving animals. The present study suggests that EIF(NS) method might serve as a noninvasive substitute for individual AIF measurement.

  20. Olfactometer for functional resonance imaging

    International Nuclear Information System (INIS)

    Andrieu, Patrice

    2013-01-01

    The Magnetic Resonance Imaging (fMRI) has been developing for twenty years. Indeed, the marketing of high-resolution MRI (5 Tesla and 7 Tesla recently) allowed the study of brain mechanisms. The research work of this PHD was to develop instrumentation for objective studies of brain behavior during a sensory stimulation. We are interested in the study of olfaction. We have designed and built a six-channel olfactometer, synchronized with breathing and controlled by computer. The originality of our work lies in the modularity of our device, which makes it adaptable to a wide range of studies. We also propose a new method to change the intensity of stimulation delivered: the Pulse Width Modulation (PWM). This device has been used in several studies in fMRI. The effectiveness of the PWM is highlighted in a psychophysical study described in this manuscript. (author)

  1. Fluorescent Nanoparticle Imaging Allows Noninvasive Evaluation of Immune Cell Modulation in Esophageal Dysplasia

    Directory of Open Access Journals (Sweden)

    Peiman Habibollahi

    2014-05-01

    Full Text Available Esophageal tumors provide unique challenges and opportunities for developing and testing surveillance imaging technology for different tumor microenvironment components, including assessment of immune cell modulation, with the ultimate goal of promoting early detection and response evaluation. In this context, accessibility through the lumen using a minimally invasive approach provides a means for repetitive evaluation longitudinally by combining fluorescent endoscopic imaging technology with novel fluorescent nanoparticles that are phagocytized by immune cells in the microenvironment. The agent we developed for imaging is synthesized from Feraheme (ferumoxytol, a Food and Drug Administration-approved monocrystaline dextran-coated iron oxide nanoparticle, which we conjugated to a near-infrared fluorochrome, CyAL5.5. We demonstrate a high level of uptake of the fluorescent nanoparticles by myeloid-derived suppressor cells (MDSCs in the esophagus and spleen of L2Cre;p120ctnflox/flox mice. These mice develop esophageal dysplasia leading to squamous cell carcinoma; we have previously demonstrated that dysplastic and neoplastic esophageal lesions in these mice have an immune cell infiltration that is dominated by MDSCs. In the L2Cre;p120ctnflox/flox mice, evaluation of the spleen reveals that nearly 80% of CD45+ leukocytes that phagocytized the nanoparticle were CD11b+Gr1+ MDSCs. After dexamethasone treatment, we observed concordant decreased fluorescent signal from esophageal lesions during fluorescent endoscopy and decreased CyAL5.5-fluorescent-positive immune cell infiltration in esophageal dysplastic lesions by fluorescence-activated cell sorting analysis. Our observations suggest that this translatable technology may be used for the early detection of dysplastic changes and the serial assessment of immunomodulatory therapy and to visualize changes in MDSCs in the esophageal tumor microenvironment.

  2. Noninvasive quantification of myocardial perfusion heterogeneity by Markovian analysis in SPECT nuclear imaging

    International Nuclear Information System (INIS)

    Pons, G.

    2011-01-01

    Cardiovascular diseases are the leading cause of mortality worldwide, and third of these deaths are caused by coronary artery disease and rupture of vulnerable atherosclerotic plaques. The heterogeneous alteration of the coronary microcirculation is an early phenomenon associated with many cardiovascular risk factors that can strongly predict the subsequent development of coronary artery disease, and lead to the appearance of myocardial perfusion heterogeneity. Nuclear medicine allows the study of myocardial perfusion in clinical routine through scintigraphic scans performed after injection of a radioactive tracer of coronary blood flow. Analysis of scintigraphic perfusion images currently allows the detection of myocardial ischemia, but the ability of the technique to measure the perfusion heterogeneity in apparently normally perfused areas is unknown. The first part of this thesis focuses on a retrospective clinical study to determine the feasibility of myocardial perfusion heterogeneity quantification measured by Thallium-201 single photon emission computed tomography (SPECT) in diabetic patients compared with healthy subjects. The clinical study has demonstrated the ability of routine thallium-201 SPECT imaging to quantify greater myocardial perfusion heterogeneity in diabetic patients compared with normal subjects. The second part of this thesis tests the hypothesis that the myocardial perfusion heterogeneity could be quantified in small animal SPECT imaging by Thallium-201 and/or Technetium-99m-MIBI in an experimental study using two animal models of diabetes, and is correlated with histological changes. The lack of difference in myocardial perfusion heterogeneity between control and diabetic animals suggests that animal models are poorly suited, or that the technology currently available does not seem satisfactory to obtain similar results as the clinical study. (author)

  3. Structural basis for pulmonary functional imaging

    International Nuclear Information System (INIS)

    Itoh, Harumi; Nakatsu, Masashi; Yoxtheimer, Lorene M.; Uematsu, Hidemasa; Ohno, Yoshiharu; Hatabu, Hiroto

    2001-01-01

    An understanding of fine normal lung morphology is important for effective pulmonary functional imaging. The lung specimens must be inflated. These include (a) unfixed, inflated lung specimen, (b) formaldehyde fixed lung specimen, (c) fixed, inflated dry lung specimen, and (d) histology specimen. Photography, magnified view, radiograph, computed tomography, and histology of these specimens are demonstrated. From a standpoint of diagnostic imaging, the main normal lung structures consist of airways (bronchi and bronchioles), alveoli, pulmonary vessels, secondary pulmonary lobules, and subpleural pulmonary lymphatic channels. This review summarizes fine radiologic normal lung morphology as an aid to effective pulmonary functional imaging

  4. Double contrast barium enema combined with non-invasive imaging in peritoneal mesothelioma

    International Nuclear Information System (INIS)

    Cozzi, G.; Bellomi, M.; Frigerio, L.F.; Ostinelli, C.; Marchiano, A.; Petrillo, R.; Severini, A.; Milan Univ.

    1989-01-01

    Mesotheliomas are rare tumors arising from serosal linings of the major serous cavities. Five patients with peritoneal mesothelioma underwent a double contrast barium enema (DCBE) and ultrasonography (US) (2 patients), computed tomography (CT) (3 patients) and/or magnetic resonance imaging (MRI) (3 patients). The diagnosis was confirmed at laparotomy. The radiologic pattern at DCBE is unspecific and consists of compression and dislocation of bowel loops by extrinsic masses. Mesenteric retraction and segmental stenosis may be present. In one patient DCBE was normal. US, CT and MRI findings are also unspecific but when combined with information obtained from DCBE the site and abdominal extension of the disease are well defined. (orig.)

  5. Evaluation of renal transplant perfusion by functional imaging

    International Nuclear Information System (INIS)

    Nicoletti, R.

    1990-01-01

    Radionuclide angiography (RNA) is used as a noninvasive method for the evaluation of renal transplant perfusion. The computer processing method generally used, based on regions of interest, is unsatisfactory because it does not permit the regional differentiation of perfusion defects. Furthermore, the subjective delineation of the regions of interest introduces considerable inter-observer variation of results. We developed a processing method which is less operator-dependent and permits the evaluation of local defects; it is based on the concept of functional imaging. The method was evaluated in 62 patient examinations, which were subdivided into four groups: Normal transplant perfusion (23 examinations), acute tubular necrose (ATN) (16), cellular rejection (13), and vascular rejection (10). Quantitative results derived from profile curves were combined with visual estimation of the functional images and yielded a synoptic graph which allowed differentiation into three groups: Normal transplant perfusion (sensitivity 0.78, specificity 0.97), ATN or cellular rejection (sens. 0.83, spec. 0.82), and vascular rejection (sens. 0.90, spec. 0.92). (orig.)

  6. Noninvasive deep brain stimulation using focused energy sources

    NARCIS (Netherlands)

    Sierra, C. V. Rizzo

    2010-01-01

    A non-invasive methodological possibility for brain stimulation through the simultaneous use of an external energy beam and an existing brain imaging system such as functional magnetic resonance imaging (fMRI) is herein proposed; the main advantage is to confine the stimulation into a single brain

  7. 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.

  8. Noninvasive measurements of cardiac high-energy phosphate metabolites in dilated cardiomyopathy by using 31P spectroscopic chemical shift imaging

    International Nuclear Information System (INIS)

    Hansch, A.; Rzanny, R.; Heyne, J.-P.; Reichenbach, J.R.; Kaiser, W.A.; Leder, U.

    2005-01-01

    Dilated cardiomyopathy (DCM) is accompanied by an impaired cardiac energy metabolism. The aim of this study was to investigate metabolic ratios in patients with DCM compared to controls by using spectroscopic two-dimensional chemical shift imaging (2D-CSI). Twenty volunteers and 15 patients with severe symptoms (left ventricular ejection fraction, LVEF 30%) of DCM were investigated. Cardiac 31 P MR 2D-CSI measurements (voxel size: 40 x 40 x 100 mm 3 ) were performed with a 1.5 T whole-body scanner. Measurement time ranged from 15 min to 30 min. Peak areas and ratios of different metabolites were evaluated, including high-energy phosphates (PCr, ATP), 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters (PDE). In addition, we evaluated how PCr/ATP ratios correlate with LVEF as an established prognostic factor of heart failure. The PCr/γ-ATP ratio was significantly decreased in patients with moderate and severe DCM and showed a linear correlation with reduced LVEFs. PDE/ATP ratios were significantly increased only in patients with severe DCM as compared to volunteers. Applying 31 P MRS with commonly-available 2D-CSI sequences is a valuable technique to evaluate DCM by determining PCr/ATP ratios noninvasively. In addition to reduced PCr/ATP ratios observed in patients suffering from DCM, significantly-increased PDE/ATP ratios were found in patients with severe DCM. (orig.)

  9. High-resolution non-invasive 3D imaging of paint microstructure by synchrotron-based X-ray laminography

    International Nuclear Information System (INIS)

    Reischig, Peter; Helfen, Lukas; Wallert, Arie; Baumbach, Tilo; Dik, Joris

    2013-01-01

    The characterisation of the microstructure and micromechanical behaviour of paint is key to a range of problems related to the conservation or technical art history of paintings. Synchrotron-based X-ray laminography is demonstrated in this paper to image the local sub-surface microstructure in paintings in a non-invasive and non-destructive way. Based on absorption and phase contrast, the method can provide high-resolution 3D maps of the paint stratigraphy, including the substrate, and visualise small features, such as pigment particles, voids, cracks, wood cells, canvas fibres etc. Reconstructions may be indicative of local density or chemical composition due to increased attenuation of X-rays by elements of higher atomic number. The paint layers and their interfaces can be distinguished via variations in morphology or composition. Results of feasibility tests on a painting mockup (oak panel, chalk ground, vermilion and lead white paint) are shown, where lateral and depth resolution of up to a few micrometres is demonstrated. The method is well adapted to study the temporal evolution of the stratigraphy in test specimens and offers an alternative to destructive sampling of original works of art. (orig.)

  10. Increased Understanding of Stem Cell Behavior in Neurodegenerative and Neuromuscular Disorders by Use of Noninvasive Cell Imaging.

    Science.gov (United States)

    Holvoet, Bryan; De Waele, Liesbeth; Quattrocelli, Mattia; Gheysens, Olivier; Sampaolesi, Maurillio; Verfaillie, Catherine M; Deroose, Christophe M

    2016-01-01

    Numerous neurodegenerative and neuromuscular disorders are associated with cell-specific depletion in the human body. This imbalance in tissue homeostasis is in healthy individuals repaired by the presence of endogenous stem cells that can replace the lost cell type. However, in most disorders, a genetic origin or limited presence or exhaustion of stem cells impairs correct cell replacement. During the last 30 years, methods to readily isolate and expand stem cells have been developed and this resulted in a major change in the regenerative medicine field as it generates sufficient amount of cells for human transplantation applications. Furthermore, stem cells have been shown to release cytokines with beneficial effects for several diseases. At present however, clinical stem cell transplantations studies are struggling to demonstrate clinical efficacy despite promising preclinical results. Therefore, to allow stem cell therapy to achieve its full potential, more insight in their in vivo behavior has to be achieved. Different methods to noninvasively monitor these cells have been developed and are discussed. In some cases, stem cell monitoring even reached the clinical setting. We anticipate that by further exploring these imaging possibilities and unraveling their in vivo behavior further improvement in stem cell transplantations will be achieved.

  11. Increased Understanding of Stem Cell Behavior in Neurodegenerative and Neuromuscular Disorders by Use of Noninvasive Cell Imaging

    Directory of Open Access Journals (Sweden)

    Bryan Holvoet

    2016-01-01

    Full Text Available Numerous neurodegenerative and neuromuscular disorders are associated with cell-specific depletion in the human body. This imbalance in tissue homeostasis is in healthy individuals repaired by the presence of endogenous stem cells that can replace the lost cell type. However, in most disorders, a genetic origin or limited presence or exhaustion of stem cells impairs correct cell replacement. During the last 30 years, methods to readily isolate and expand stem cells have been developed and this resulted in a major change in the regenerative medicine field as it generates sufficient amount of cells for human transplantation applications. Furthermore, stem cells have been shown to release cytokines with beneficial effects for several diseases. At present however, clinical stem cell transplantations studies are struggling to demonstrate clinical efficacy despite promising preclinical results. Therefore, to allow stem cell therapy to achieve its full potential, more insight in their in vivo behavior has to be achieved. Different methods to noninvasively monitor these cells have been developed and are discussed. In some cases, stem cell monitoring even reached the clinical setting. We anticipate that by further exploring these imaging possibilities and unraveling their in vivo behavior further improvement in stem cell transplantations will be achieved.

  12. 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.

  13. Restoring cognitive functions using non-invasive brain stimulation techniques in patients with cerebellar disorders

    Directory of Open Access Journals (Sweden)

    Paul A Pope

    2014-04-01

    Full Text Available Numerous studies have highlighted the possibility of modulating the excitability of cerebro-cerebellar circuits bi-directionally using transcranial electrical brain stimulation, in a manner akin to that observed using magnetic stimulation protocols. It has been proposed that cerebellar stimulation activates Purkinje cells in the cerebellar cortex, leading to inhibition of the dentate nucleus, which exerts a tonic facilitatory drive onto motor and cognitive regions of cortex through a synaptic relay in the ventral-lateral thalamus. Some cerebellar deficits present with cognitive impairments if damage to non-motor regions of the cerebellum disrupts the coupling with cerebral cortical areas for thinking and reasoning. Indeed, white matter changes in the dentato-rubral tract correlate with cognitive assessments in patients with Friedreich ataxia, suggesting that this pathway is one component of the anatomical substrate supporting a cerebellar contribution to cognition. An understanding of the physiology of the cerebro-cerebellar pathway previously helped us to constrain our interpretation of results from two recent studies in which we showed cognitive enhancements in healthy participants during tests of arithmetic after electrical stimulation of the cerebellum, but only when task demands were high. Others studies have also shown how excitation of the prefrontal cortex can enhance performance in a variety of working memory tasks. Thus, future efforts might be guided towards neuro-enhancement in certain patient populations, using what is commonly termed 'non-invasive brain stimulation' as a cognitive rehabilitation tool to modulate cerebro-cerebellar circuits, or for stimulation over the cerebral cortex to compensate for decreased cerebellar drive to this region. This article will address these possibilities with a review of the relevant literature covering ataxias and cerebellar cognitive affective disorders, which are characterized by thalamo

  14. Noninvasive positive pressure ventilation enhances the effects of aerobic training on cardiopulmonary function.

    Directory of Open Access Journals (Sweden)

    Takashi Moriki

    Full Text Available The purpose of this study was to determine the effect of aerobic training under noninvasive positive pressure ventilation (NPPV on maximal oxygen uptake ([Formula: see text].Ten healthy young male volunteers participated in the study. Before the training, stroke volume (SV and cardiac output (CO were measured in all subjects under 0, 4, 8, and 12 cmH2O NPPV at rest. Then, the subjects exercised on a cycle ergometer at 60% of pre-training [Formula: see text] for 30 min daily for 5 consecutive days with/without NPPV. The 5-day exercise protocol was repeated after a three-week washout period without/with NPPV. The primary endpoint was changes in [Formula: see text]. The secondary endpoints were changes in SV, CO, maximum heart rate (HRmax, maximum respiratory rate (RRmax, maximum expiratory minute volume (VEmax and the percent change in plasma volume (PV.NPPV at 12 cmH2O significantly reduced SV and CO at rest. [Formula: see text] significantly increased after 5 days training with and without NPPV, but the magnitude of increase in [Formula: see text] after training under 12 cmH2O NPPV was significantly higher than after training without NPPV. VEmax significantly increased after training under NPPV, but not after training without NPPV. HRmax and RRmax did not change during training irrespective of NPPV. The percent change in PV was similar between training with and without NPPV. The 5-day training program with NPPV resulted in greater improvement in [Formula: see text] than without NPPV.Aerobic training under NPPV has add-on effects on [Formula: see text] and exercise-related health benefits in healthy young men.

  15. Non-invasive high-resolution tracking of human neuronal pathways: diffusion tensor imaging at 7T with 1.2 mm isotropic voxel size

    Science.gov (United States)

    Lützkendorf, Ralf; Hertel, Frank; Heidemann, Robin; Thiel, Andreas; Luchtmann, Michael; Plaumann, Markus; Stadler, Jörg; Baecke, Sebastian; Bernarding, Johannes

    2013-03-01

    Diffusion tensor imaging (DTI) allows characterizing and exploiting diffusion anisotropy effects, thereby providing important details about tissue microstructure. A major application in neuroimaging is the so-called fiber tracking where neuronal connections between brain regions are determined non-invasively by DTI. Combining these neural pathways within the human brain with the localization of activated brain areas provided by functional MRI offers important information about functional connectivity of brain regions. However, DTI suffers from severe signal reduction due to the diffusion-weighting. Ultra-high field (UHF) magnetic resonance imaging (MRI) should therefore be advantageous to increase the intrinsic signal-to-noise ratio (SNR). This in turn enables to acquire high quality data with increased resolution, which is beneficial for tracking more complex fiber structures. However, UHF MRI imposes some difficulties mainly due to the larger B1 inhomogeneity compared to 3T MRI. We therefore optimized the parameters to perform DTI at a 7 Tesla whole body MR scanner equipped with a high performance gradient system and a 32-channel head receive coil. A Stesjkal Tanner spin-echo EPI sequence was used, to acquire 110 slices with an isotropic voxel-size of 1.2 mm covering the whole brain. 60 diffusion directions were scanned which allows calculating the principal direction components of the diffusion vector in each voxel. The results prove that DTI can be performed with high quality at UHF and that it is possible to explore the SNT benefit of the higher field strength. Combining UHF fMRI data with UHF DTI results will therefore be a major step towards better neuroimaging methods.

  16. 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.

  17. Noninvasive image texture analysis differentiates K-ras mutation from pan-wildtype NSCLC and is prognostic.

    Directory of Open Access Journals (Sweden)

    Glen J Weiss

    Full Text Available Non-invasive characterization of a tumor's molecular features could enhance treatment management. Quantitative computed tomography (CT based texture analysis (QTA has been used to derive tumor heterogeneity information, and the appearance of the tumors has been shown to relate to patient outcome in non-small cell lung cancer (NSCLC and other cancers. In this study, we examined the potential of tumoral QTA to differentiate K-ras mutant from pan-wildtype tumors and its prognostic potential using baseline pre-treatment non-contrast CT imaging in NSCLC.Tumor DNA from patients with early-stage NSCLC was analyzed on the LungCarta Panel. Cases with a K-ras mutation or pan-wildtype for 26 oncogenes and tumor suppressor genes were selected for QTA. QTA was applied to regions of interest in the primary tumor. Non-parametric Mann Whitney test assessed the ability of the QTA, clinical and patient characteristics to differentiate between K-ras mutation from pan-wildtype. A recursive decision tree was developed to determine whether the differentiation of K-ras mutant from pan-wildtype tumors could be improved by sequential application of QTA parameters. Kaplan-Meier survival analysis assessed the ability of these markers to predict survival.QTA was applied to 48 cases identified, 27 had a K-ras mutation and 21 cases were pan-wildtype. Positive skewness and lower kurtosis were significantly associated with the presence of a K-ras mutation. A five node decision tree had sensitivity, specificity, and accuracy values (95% CI of 96.3% (78.1-100, 81.0% (50.5-97.4, and 89.6% (72.9-97.0; respectively. Kurtosis was a significant predictor of OS and DFS, with a lower kurtosis value linked with poorer survival.Lower kurtosis and positive skewness are significantly associated with K-ras mutations. A QTA feature such as kurtosis is prognostic for OS and DFS. Non-invasive QTA can differentiate the presence of K-ras mutation from pan-wildtype NSCLC and is associated with

  18. 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

  19. 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.

  20. Noninvasive and painless magnetic stimulation of nerves improved brain motor function and mobility in a cerebral palsy case.

    Science.gov (United States)

    Flamand, Véronique H; Schneider, Cyril

    2014-10-01

    Motor deficits in cerebral palsy disturb functional independence. This study tested whether noninvasive and painless repetitive peripheral magnetic stimulation could improve motor function in a 7-year-old boy with spastic hemiparetic cerebral palsy. Stimulation was applied over different nerves of the lower limbs for 5 sessions. We measured the concurrent aftereffects of this intervention on ankle motor control, gait (walking velocity, stride length, cadence, cycle duration), and function of brain motor pathways. We observed a decrease of ankle plantar flexors resistance to stretch, an increase of active dorsiflexion range of movement, and improvements of corticospinal control of ankle dorsiflexors. Joint mobility changes were still present 15 days after the end of stimulation, when all gait parameters were also improved. Resistance to stretch was still lower than prestimulation values 45 days after the end of stimulation. This case illustrates the sustained effects of repetitive peripheral magnetic stimulation on brain plasticity, motor function, and gait. It suggests a potential impact for physical rehabilitation in cerebral palsy. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  1. Non-invasive 3D facial analysis and surface electromyography during functional pre-orthodontic therapy: a preliminary report

    Directory of Open Access Journals (Sweden)

    Gianluca M. Tartaglia

    2009-10-01

    Full Text Available OBJECTIVES: Functional orthodontic devices can modify oral function thus permitting more adequate growth processes. The assessment of their effects should include both facial morphology and muscle function. This preliminary study investigated whether a preformed functional orthodontic device could induce variations in facial morphology and function along with correction of oral dysfunction in a group of orthodontic patients in the mixed and early permanent dentitions. MATERIAL AND METHODS: The three-dimensional coordinates of 50 facial landmarks (forehead, eyes, nose, cheeks, mouth, jaw and ears were collected in 10 orthodontic male patients aged 8-13 years, and in 89 healthy reference boys of the same age. Soft tissue facial angles, distances, and ratios were computed. Surface electromyography of the masseter and temporalis muscles was performed, and standardized symmetry, muscular torque and activity were calculated. Soft-tissue facial modifications were analyzed non-invasively before and after a 6-month treatment with a functional device. Comparisons were made with z-scores and paired Student's t-tests. RESULTS: The 6-month treatment stimulated mandibular growth in the anterior and inferior directions, with significant variations in three-dimensional facial divergence and facial convexity. The modifications were larger in the patients than in reference children. In several occasions, the discrepancies relative to the norm became not significant after treatment. No significant variations in standardized muscular activity were found. CONCLUSIONS: Preliminary results showed that the continuous and correct use of the functional device induced measurable intraoral (dental arches and extraoral (face morphological modifications. The device did not modify the functional equilibrium of the masticatory muscles.

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

    Science.gov (United States)

    Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M.

    2014-01-01

    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. PMID:24506637

  3. Functional imaging of epileptic activity in humans

    OpenAIRE

    Vulliemoz, Serge

    2012-01-01

    Around 20% of patients suffering from epilepsy have medically refractory seizures and epilepsy surgery can offer a cure or at least a significant improvement of their seizures. in well selected patients. A comprehensive work-up combining different imaging techniques is necessary to localise brain regions involved in the epileptic network. Simultaneous ElectroEncephaloGraphy and functional Magnetic Resonance Imaging (EEG-fMRI) is a new technique that allows mapping epileptic networks at a whol...

  4. Imaging cellular and molecular biological functions

    Energy Technology Data Exchange (ETDEWEB)

    Shorte, S.L. [Institut Pasteur, 75 - Paris (France). Plateforme d' Imagerie Dynamique PFID-Imagopole; Frischknecht, F. (eds.) [Heidelberg Univ. Medical School (Germany). Dept. of Parasitology

    2007-07-01

    'Imaging cellular and molecular biological function' provides a unique selection of essays by leading experts, aiming at scientist and student alike who are interested in all aspects of modern imaging, from its application and up-scaling to its development. Indeed the philosophy of this volume is to provide student, researcher, PI, professional or provost the means to enter this applications field with confidence, and to construct the means to answer their own specific questions. (orig.)

  5. Imaging tools to study pharmacology: functional MRI on small rodents

    Directory of Open Access Journals (Sweden)

    Elisabeth eJonckers

    2015-10-01

    Full Text Available Functional Magnetic Resonance Imaging (fMRI is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD fMRI techniques, including resting state (rsfMRI, stimulus-evoked (st-fMRI, and pharmacological MRI (phMRI. Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anaesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically-induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest (ROIs. In addition, fMRI techniques allow one to dissect how specific modifications (e.g. treatment, lesion etc. modulate the functioning of specific brain areas (st-fMRI, phMRI and how functional connectivity (rsfMRI between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with

  6. Noninvasive Evaluation of Bladder Wall Mechanical Properties as a Function of Filling Volume: Potential Application in Bladder Compliance Assessment.

    Directory of Open Access Journals (Sweden)

    Ivan Nenadic

    Full Text Available We propose a novel method to monitor bladder wall mechanical properties as a function of filling volume, with the potential application to bladder compliance assessment. The proposed ultrasound bladder vibrometry (UBV method uses ultrasound to excite and track Lamb waves on the bladder wall from which its mechanical properties are derived by fitting measurements to an analytical model. Of particular interest is the shear modulus of bladder wall at different volumes, which we hypothesize, is similar to measuring the compliance characteristics of the bladder.Three experimental models were used: 1 an ex vivo porcine model where normal and aberrant (stiffened by formalin bladders underwent evaluation by UBV; 2 an in vivo study to evaluate the performance of UBV on patients with clinically documented compliant and noncompliant bladders undergoing UDS; and 3 a noninvasive UBV protocol to assess bladder compliance using oral hydration and fractionated voiding on three healthy volunteers.The ex vivo studies showed a high correlation between the UBV parameters and direct pressure measurement (R2 = 0.84-0.99. A similar correlation was observed for 2 patients with compliant and noncompliant bladders (R2 = 0.89-0.99 undergoing UDS detrusor pressure-volume measurements. The results of UBV on healthy volunteers, performed without catheterization, were comparable to a compliant bladder patient.The utility of UBV as a method to monitor changes in bladder wall mechanical properties is validated by the high correlation with pressure measurements in ex vivo and in vivo patient studies. High correlation UBV and UDS in vivo studies demonstrated the potential of UBV as a bladder compliance assessment tool. Results of studies on healthy volunteers with normal bladders demonstrated that UBV could be performed noninvasively. Further studies on a larger cohort are needed to fully validate the use of UBV as a clinical tool for bladder compliance assessment.

  7. Radionuclide imaging of bone marrow disorders

    NARCIS (Netherlands)

    Agool, Ali; Glaudemans, Andor W. J. M.; Boersma, Hendrikus H.; Dierckx, Rudi A. J. O.; Vellenga, Edo; Slart, Riemer H. J. A.

    Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use

  8. 7-Tesla Magnetic Resonance Imaging Precisely and Noninvasively Reflects Inflammation and Remodeling of the Skeletal Muscle in a Mouse Model of Antisynthetase Syndrome

    Science.gov (United States)

    Sciorati, Clara; Esposito, Antonio; Campana, Lara; Canu, Tamara; Monno, Antonella; Palmisano, Anna; De Cobelli, Francesco; Del Maschio, Alessandro; Ascheman, Dana P.; Manfredi, Angelo A.; Rovere-Querini, Patrizia

    2014-01-01

    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. PMID:24895622

  9. 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.

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

    International Nuclear Information System (INIS)

    Wen Bixiu; Burgman, Paul; Zanzonico, Pat; O'Donoghue, Joseph; Li, Gloria C.; Ling, C. Clifton; Cai Shangde; Finn, Ron; Serganova, Inna; Blasberg, Ronald; Gelovani, Juri

    2004-01-01

    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 124 I-labeled reporter substrate 2'-fluoro-2'-deoxy-1-β-d-arabinofuranosyl-5-iodouracil ( 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 124 I-FIAU, providing a distribution of the hypoxia-induced molecular events. The distribution of 124 I-FIAU was also compared with that of an exogenous hypoxic cell marker, 18 F-fluoromisonidazole (FMISO). Our results showed that 124 I-FIAU microPET imaging of the hypoxia-induced reporter gene expression is feasible, and that the intratumoral distributions of 124 I-FIAU and 18 F-FMISO are similar. In tumor sections, detailed radioactivity distributions were obtained with PPI which also showed similarity between 124 I-FIAU and 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 exogenous markers for tumor hypoxia. (orig.)

  11. Functional brain imaging - baric and clinical questions

    International Nuclear Information System (INIS)

    Mager, T.; Moeller, H.J.

    1997-01-01

    The advancing biological knowledge of disease processes plays a central part in the progress of modern psychiatry. An essential contribution comes from the functional and structural brain imaging techniques (CT, MRI, SPECT, PET). Their application is important for biological oriented research in psychiatry and there is also a growing relevance in clinical aspects. This development is taken into account by recent diagnostic classification systems in psychiatry. The capabilities and limitations of functional brain imaging in the context of research and clinic will be presented and discussed by examples and own investigations. (orig.) [de

  12. Functionalized silica nanoparticles: a platform for fluorescence imaging at the cell and small animal levels.

    Science.gov (United States)

    Wang, Kemin; He, Xiaoxiao; Yang, XiaoHai; Shi, Hui

    2013-07-16

    Going in vivo, including living cells and the whole body, is very important for gaining a better understanding of the mystery of life and requires specialized imaging techniques. The diversity, composition, and temporal-spatial variation of life activities from cells to the whole body require the analysis techniques to be fast-response, noninvasive, highly sensitive, and stable, in situ and in real-time. Functionalized nanoparticle-based fluorescence imaging techniques have the potential to meet such needs through real-time and noninvasive visualization of biological events in vivo. Functionalized silica nanoparticles (SiNPs) doped with fluorescent dyes appear to be an ideal and flexible platform for developing fluorescence imaging techniques used in living cells and the whole body. We can select and incorporate different dyes inside the silica matrix either noncovalently or covalently. These form the functionalized hybrid SiNPs, which support multiplex labeling and ratiometric sensing in living systems. Since the silica matrix protects dyes from outside quenching and degrading factors, this enhances the photostability and biocompatibility of the SiNP-based probes. This makes them ideal for real-time and long-time tracking. One nanoparticle can encapsulate large numbers of dye molecules, which amplifies their optical signal and temporal-spatial resolution response. Integrating fluorescent dye-doped SiNPs with targeting ligands using various surface modification techniques can greatly improve selective recognition. Along with the endocytosis, functionalized SiNPs can be efficiently internalized into cells for noninvasive localization, assessment, and monitoring. These unique characteristics of functionalized SiNPs substantially support their applications in fluorescence imaging in vivo. In this Account, we summarize our efforts to develop functionalized dye-doped SiNPs for fluorescence imaging at the cell and small animal levels. We first discuss how to design and

  13. Localization of focal epileptic discharges using functional connectivity magnetic resonance imaging.

    Science.gov (United States)

    Stufflebeam, Steven M; Liu, Hesheng; Sepulcre, Jorge; Tanaka, Naoaki; Buckner, Randy L; Madsen, Joseph R

    2011-06-01

    In patients with medically refractory epilepsy the accurate localization of the seizure onset zone is critical for successful surgical treatment. The object of this study was to investigate whether the degree of coupling of spontaneous brain activity as measured with functional connectivity MR imaging (fcMR imaging) can accurately identify and localize epileptic discharges. The authors studied 6 patients who underwent fcMR imaging presurgical mapping and subsequently underwent invasive electroencephalography. Focal regions of statistically significant increases in connectivity were identified in 5 patients when compared with an ad hoc normative sample of 300 controls. The foci identified by fcMR imaging overlapped the epileptogenic areas identified by invasive encephalography in all 5 patients. These results suggest that fcMR imaging may provide an effective high-spatial resolution and noninvasive method of localizing epileptic discharges in patients with refractory epilepsy.

  14. An advanced design of non-radioactive image capturing and management system for applications in non-invasive skin disorder diagnosis

    Science.gov (United States)

    Liu, Carol Y. B.; Luk, David C. K.; Zhou, Kany S. Y.; So, Bryan M. K.; Louie, Derek C. H.

    2015-03-01

    Due to the increasing incidences of malignant melanoma, there is a rising demand for assistive technologies for its early diagnosis and improving the survival rate. The commonly used visual screening method is with limited accuracy as the early phase of melanoma shares many clinical features with an atypical nevus, while conventional dermoscopes are not user-friendly in terms of setup time and operations. Therefore, the development of an intelligent and handy system to assist the accurate screening and long-term monitoring of melanocytic skin lesions is crucial for early diagnosis and prevention of melanoma. In this paper, an advanced design of non-invasive and non-radioactive dermoscopy system was reported. Computer-aided simulations were conducted for optimizing the optical design and uniform illumination distribution. Functional prototype and the software system were further developed, which could enable image capturing at 10x amplified and general modes, convenient data transmission, analysis of dermoscopic features (e.g., asymmetry, border irregularity, color, diameter and dermoscopic structure) for assisting the early detection of melanoma, extract patient information (e.g. code, lesion location) and integrate with dermoscopic images, thus further support long term monitoring of diagnostic analysis results. A clinical trial study was further conducted on 185 Chinese children (0-18 years old). The results showed that for all subjects, skin conditions diagnosed based on the developed system accurately confirmed the diagnoses by conventional clinical procedures. Besides, clinical analysis on dermoscopic features and a potential standard approach by the developed system to support identifying specific melanocytic patterns for dermoscopic examination in Chinese children were also reported.

  15. The sharp reductions in medicare payments for noninvasive diagnostic imaging in recent years: will they satisfy the federal policymakers?

    Science.gov (United States)

    Levin, David C; Rao, Vijay M; Parker, Laurence; Frangos, Andrea J

    2012-09-01

    The aim of this study was to examine recent trends in Medicare reimbursements for noninvasive diagnostic imaging (NDI). The Medicare Part B databases for 2000 to 2010 were used. For each procedure code, these files provide payment and other data. All NDI codes were selected. Medicare physician specialty codes were used to identify radiologists, cardiologists, all other nonradiologist physicians as a group, and independent diagnostic testing facilities. Part B NDI payment trends were tracked. Overall Part B spending for NDI rose from $5.921 billion in 2000 to $11.910 billion in 2006 (+101%). There was then a sharp drop in 2007, resulting from the implementation of the Deficit Reduction Act. This was followed by a slight rise in 2008, then successive smaller drops the next 2 years, reaching $9.457 billion in 2010 (-21% vs 2006). Radiologists' payments were $2.936 billion in 2000, rose to a peak of $5.3 billion in 2006 (+81%), then dropped to $4.712 billion in 2010 (-11% vs 2006). Cardiologists' NDI payments were $1.327 billion in 2000, peaking at $2.998 billion in 2006 (+126%), then dropping to $1.996 billion in 2010 (-33% vs 2006). Other physicians' payments were $1.106 billion in 2000, peaking at $2.378 billion in 2006 (+115%), then dropping to $1.968 billion in 2010 (-17% vs 2006). Similar trends occurred in independent diagnostic testing facilities. After years of rapid growth in Medicare NDI payments, an abrupt reversal occurred starting in 2007. By 2010, overall NDI costs to Medicare Part B were down 21% compared with their 2006 peak. It is unclear whether this large payment reduction will satisfy federal policymakers. Copyright © 2012 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  16. Magnetic resonance imaging as a technique for assessing noninvasive tissue ablation using high-intensity ultrasound: an experimental study.

    Science.gov (United States)

    Honeck, Patrick; Peters, Kristina; Wendt-Nordahl, Gunnar; Bolenz, Christian; Alken, Peter; Michel, Maurice-Stephan; Jenne, Jürgen W; Häcker, Axel

    2009-01-01

    As a form of noninvasive extracorporeal application, acoustic energy offers an alternative to nephron-sparing surgery for renal masses smaller than 4 cm. The availability of a reliable tool for monitoring the therapy is a prerequisite for safe and successful high-intensity focused ultrasound (HIFU) application. The aim of this study was to evaluate the morphologic visualization of HIFU lesions using MRI. We used the ex vivo model of the isolated perfused porcine kidney. Treatment was performed using an experimental HIFU system. Complex lesions were induced in 10 kidneys. MRI was performed under constant perfusion of the kidneys. To determine the exact lesion size, we performed a fat-saturated, T1-weighted, volumetric interpolated breath-hold MRI sequence. For perfusion imaging, we used a three-dimensional fast low-angle shot sequence. Subsequently, the lesions were evaluated macroscopically. The width of the complex lesions was defined as x, the length as y, and the depth as z. The MRI scans showed good soft tissue contrast in all sequences. The mean difference for the width of the lesions was 0.2 +/- 1.1 mm; for lesion length and depth, it was 1.7 +/- 1.8 mm and 1.1 +/- 1.3 mm for lesion width, respectively. Statistical evaluation of the x values showed no significant difference between the macroscopic and the MRI data (P = 0.85). The y and z values, however, showed a statistically significant difference (P = 0.071). MRI could be a diagnostic tool for monitoring HIFU. Before this modality can be used under clinical conditions, further technical development is indispensable, especially with respect to reducing the measuring times.

  17. Functional connectivity in the mouse brain imaged by B-mode photoacoustic microscopy

    Science.gov (United States)

    Nasiriavanaki, Mohammadreza; Xing, Wenxin; Xia, Jun; Wang, Lihong V.

    2014-03-01

    The increasing use of mouse models for human brain disease studies, coupled with the fact that existing functional imaging modalities cannot be easily applied to mice, presents an emerging need for a new functional imaging modality. Utilizing acoustic-resolution photoacoustic microscopy (AR-PAM), we imaged spontaneous cerebral hemodynamic fluctuations and their associated functional connections in the mouse brain. The images were acquired noninvasively in B-scan mode with a fast frame rate, a large field of view, and a high spatial resolution. At a location relative to the bregma 0, correlations were investigated inter-hemispherically between bilaterally homologous regions, as well as intra-hemispherically within the same functional regions. The functional connectivity in different functional regions was studied. The locations of these regions agreed well with the Paxinos mouse brain atlas. The functional connectivity map obtained in this study can then be used in the investigation of brain disorders such as stroke, Alzheimer's, schizophrenia, multiple sclerosis, autism, and epilepsy. Our experiments show that photoacoustic microscopy is capable to detect connectivities between different functional regions in B-scan mode, promising a powerful functional imaging modality for future brain research.

  18. Non-invasive assessment of equine muscular function: A case study ...

    African Journals Online (AJOL)

    Assessment of muscle function after an injury or during recovery is of great importance in the veterinary field. Accelerometry, bioimpedance analysis and mechanomyography/acoustic myography have been used to assess human muscular problems, but have not been applied to the veterinary clinic. We report the clinical ...

  19. Application of 5-hydroxytryptamine receptor imaging for study of neuropsychiatric disorders and brain functions

    International Nuclear Information System (INIS)

    Qiu Chun; Guan Yihui

    2011-01-01

    In the central nervous system, the widely distributed 5-hydroxytryptamine (5-HT)receptors are involved in regulating a large number of psychological and physiological functions, including mood, sleep, endocrine and autonomic nervous system. Abnormal 5-HT transmission has been implicated in a variety of neuropsychiatric disorders, such as pain, depression and epilepsy. With the development of radioligands, non-invasive nuclear imaging technique with exquisite sensitivity and specificity has been applied for delineation of neurotransmitter function in vivo. It does great benefit for researches of these diseases and development of drugs. This review provided an overview of 5-HT receptors radioligands and recent findings. (authors)

  20. Biphasic thallium 201 SPECT-imaging for the noninvasive diagnosis of myocardial perfusion abnormalities in a child with Kawasaki disease--a case report

    International Nuclear Information System (INIS)

    Hausdorf, G.; Nienaber, C.A.; Spielman, R.P.

    1988-01-01

    The mucocutaneous lymph node syndrome (Kawasaki disease) is of increasing importance for the pediatric cardiologist, for coronary aneurysms with the potential of thrombosis and subsequent stenosis can develop in the course of the disease. The authors report a 2 1/2-year-old female child in whom, fourteen months after the acute phase of Kawasaki disease, myocardial infarction occurred. Biphasic thallium 201 SPECT-imaging using dipyridamole depicted anterior wall ischemia and inferolateral infarction. This case demonstrates that noninvasive vasodilation-redistribution thallium 201 SPECT-imaging has the potential to predict reversible myocardial perfusion defects and myocardial necrosis, even in small infants with Kawasaki disease

  1. Seeing double: combined modalities in functional imaging

    Energy Technology Data Exchange (ETDEWEB)

    Del Guerra, A. E-mail: delguerra@pi.infn.it; Damiani, C.; Di Domenico, G.; Gambaccini, M.; Motta, A.; Sabba, N.; Zavattini, G

    2001-09-21

    Various dedicated instruments for combined modalities in functional imaging are being developed by our group: a small animal PET/SPECT scanner, two scintimammography apparatus for breast cancer diagnosis, one with RX/PEM and the other with RX/SPECT capability. The performance and the status of development of these devices will be reported.

  2. 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.

  3. Noninvasive Evaluation of Cardiac Function in Non Hypertensive and Asymptomatic Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Behzad Babapour

    2012-11-01

    Full Text Available Background & Objectives: Type 2 diabetes is a major cardiovascular risk factor such as HTN, HLP and smoking. A primary diabetic cardiomyopathy represents a high risk factor for heart failure in the absence of ischemic, valvular and hypertensive heart disease in the diabetic population. CAD is more common in diabetic patients and it is almost asymptomatic.   Unquestionably, an early detection of LV damage and CAD is a major goal for the prevention of cardiac disease in the diabetic population.   Methods: This study was done as Cross-Sectional method. The study sample consisted of 40 patients with type 2 diabetes mellitus without hypertension and cardiac symptoms (mean age 47 years who recourse to diabetes clinic of Ardabil Imam Khomeini Hospital during 2009-2010. Left ventricular (LV function was studied by echocardiography and exercise test using Bruce protocol. Data from the patients were collected and analyzed using SPSS 17 software.   Results: All studied cases had a normal systolic function. 22 cases (55% had diastolic dysfunction and 8 people (20% had a positive stress test, which all had diastolic dysfunction too.   Conclusion: This study showed that an impairment of left ventricular diastolic function occurs early in the natural history of diabetes mellitus and CAD is more common in diabetic patients with diastolic dysfunction.

  4. Noninvasive Monitoring of mRFP1- and mCherry-Labeled Oncolytic Adenoviruses in an Orthotopic Breast Cancer Model by Spectral Imaging

    Directory of Open Access Journals (Sweden)

    Anton V. Borovjagin

    2010-03-01

    Full Text Available Genetic capsid labeling of conditionally replicative adenoviruses (CRAds with fluorescent tags offers a potentially more accurate monitoring of those virotherapy agents in vivo. The capsid of an infectivity-enhanced CRAd, Ad5/3, delta 24, was genetically labeled with monomeric red fluorescent protein 1 (mRFP1 or its advanced derivative, “mCherry,” to evaluate the utility of each red fluorescent reporter and the benefit of CRAd capsid labeling for noninvasive virus tracking in animal tumor models by a new spectral imaging approach. Either reporter was incorporated into the CRAd particles by genetic fusion to the viral capsid protein IX. Following intratumoral injection, localization and replication of each virus in orthotopic breast cancer xenografts were analyzed by spectral imaging and verified by quantitative polymerase chain reaction. Fluorescence in tumors increased up to 2,000-fold by day 4 and persisted for 5 to 7 weeks, showing oscillatory dynamics reflective of CRAd replication cycles. Capsid labeling in conjunction with spectral imaging thus enables direct visualization and quantification of CRAd particles in tumors prior to the reporter transgene expression. This allows for noninvasive control of CRAd delivery and distribution in tumors and facilitates quantitative assessment of viral replication. Although mCherry appeared to be superior to mRFP1 as an imaging tag, both reporters showed utility for CRAd imaging applications.

  5. Visceral Afferent Pathways and Functional Brain Imaging

    Directory of Open Access Journals (Sweden)

    Stuart W.G. Derbyshire

    2003-01-01

    Full Text Available The application of functional imaging to study painful sensations has generated considerable interest regarding insight into brain dysfunction that may be responsible for functional pain such as that suffered in patients with irritable bowel syndrome (IBS. This review provides a brief introduction to the development of brain science as it relates to pain processing and a snapshot of recent functional imaging results with somatic and visceral pain. Particular emphasis is placed on current hypotheses regarding dysfunction of the brain-gut axis in IBS patients. There are clear and interpretable differences in brain activation following somatic as compared with visceral noxious sensation. Noxious visceral distension, particularly of the lower gastrointestinal tract, activates regions associated with unpleasant affect and autonomic responses. Noxious somatic sensation, in contrast, activates regions associated with cognition and skeletomotor responses. Differences between IBS patients and control subjects, however, were far less clear and interpretable. While this is in part due to the newness of this field, it also reflects weaknesses inherent within the current understanding of IBS. Future use of functional imaging to examine IBS and other functional disorders will be more likely to succeed by describing clear theoretical and clinical endpoints.

  6. Magnetic resonance hydrometry: non-invasive quantification of the exocrine pancreatic function

    International Nuclear Information System (INIS)

    Heverhagen, J.T.; Battmann, A.; Kirsch, M.; Klose, K.J.; Boehm, D.; Eissele, R.; Wagner, H.J.

    2002-01-01

    Aims: To show the ability of magnetic resonance hydrometry (MRH) to quantify the pancreatic secretion after secretin stimulation in order to distinguish between physiological excretion and reduced output in chronic pancreatitis. Methods: MRH images were acquired in a 1.0-T-clinical scanner using a body-array coil and a heavily T 2 -weighted standard single-shot TSE sequence. Thirty-one patients (14 male/17 female) who routinely underwent ERCP for suspected choledocholithiasis (n = 22), recurring abdominal pain (n = 1), icterus (n = 6) and suspected pancreatitis (n = 2) were included. During the investigation 1 CU/kg BW secretin were administered intravenously. Secreted volume of fluid, start of secretion, achievement of a plateau of secretion and a combined score of these parameters (MRH score) were assessed and evaluated. Sensitivity and specificity were calculated for these parameters. Results: 27 patients had no pancreatic pathology, and four suffered from chronic pancreatitis. Patients without pancreatic disorders produced a mean pancreatic fluid volume of 183±86 mL, whereas patients with chronic pancreatitis secreted 61±39 mL. Secretion started after a mean time of 95±94 seconds (no pancreatic impairment) and 62±13 seconds (chronic pancreatitis). The MRH score achieved a high accuracy in the detection of chronic pancreatitis. Conclusions: Our study demonstrated the feasibility of measuring pancreatic output by MRH after stimulation with secretin. Moreover, a distinction between normal secretion and patients with chronic pancreatitis is possible. (orig.) [de

  7. Functional brain imaging: an evidence-based analysis.

    Science.gov (United States)

    2006-01-01

    significantly improved specificity over another. There may be a role for fMRI in the identification of surgical candidates for tumour resection; however, this requires further research. Based on the studies available, it is unclear if MEG has similar accuracy in localizing seizure foci to intracranial electroencephalogram (ICEEG). More high-quality research is needed to establish whether there is a difference in accuracy between MEG and ICEEG. The results of the studies comparing PET to noninvasive electroencephalogram (EEG) did not demonstrate that PET was more accurate at localizing seizure foci; however, there may be some specific conditions, such as tuberous sclerosis, where PET may be more accurate than noninvasive EEG. There may be some clinical utility for MEG or fMRI in presurgical functional mapping; however, this needs further investigation involving comparisons with other modalities. The clinical utility of MRS has yet to be established for patients with epilepsy. Positron emission tomography has high sensitivity and specificity in the diagnosis of PD and the differential diagnosis of parkinsonian syndromes; however, it is unclear at this time if the addition of PET in the diagnosis of these conditions contributes to the treatment and clinical outcomes of patients. There is limited clinical utility of functional brain imaging in the management of patients with MS at this time. Diagnosis of MS is established through clinical history, evoked potentials, and MRI. Magnetic resonance imaging can identify the multifocal white lesions and other structural characteristics of MS.

  8. A noninvasive approach to quantitative functional brain mapping with H215O and positron emission tomography

    International Nuclear Information System (INIS)

    Fox, P.T.; Mintun, M.A.; Raichle, M.E.; Herscovitch, P.

    1984-01-01

    Positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) with intravenously administered 15 O-labeled water and an adaptation of the Kety autoradiographic model are well suited to the study of functional-anatomical correlations within the human brain. This model requires arterial blood sampling to determine rCBF from the regional tissue radiotracer concentration (Cr) recorded by the tomograph. Based upon the well-defined, nearly linear relation between Cr and rCBF inherent in the model, we have developed a method for estimating changes in rCBF from changes in Cr without calculating true rCBF and thus without arterial sampling. This study demonstrates that quantitative functional brain mapping does not require the determination of rCBF from Cr when regional neuronal activation is expressed as the change in rCBF from an initial, resting-state measurement. Patterned-flash visual stimulation was used to produce a wide range of increases in rCBF within the striate cortex. Changes in occipital rCBF were found to be accurately estimated directly from Cr over a series of 56 measurements on eight subjects. This adaptation of the PET/autoradiographic method serves to simplify its application and to make it more acceptable to the subject

  9. Functional imaging of the pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Lienemann, Andreas E-mail: andreaslienemann@web.de; Fischer, Tanja

    2003-08-01

    Introduction/Objective: Pelvic floor dysfunction and associated pelvic organ prolapse represent a major problem in our present-day society, mostly afflicting parous women. Magnetic resonance imaging (MRI) is assuming an increasingly important role in the more accurate delineation of the extent of the problem. This article briefly reviews one of the main radiological methods for the dynamic evaluation of the pelvic floor: functional cine MRI. Methods and Material: Out of the literature the smallest common denominator for functional cine MRI can be defined as follows: high field system; patient either in supine or sitting position; fast gradient echo sequence; midsagittal slice orientation; either a stack of slices or repeated measurements at the same slice position with the patient at rest or straining; image analysis using the pubococcygeal reference line. Results: All except two publications stress the usefulness of functional cine MRI in the evaluation of patients with organ descent and prolapse. This well accepted method allows for the visualization of all relevant structures in the anterior, middle and posterior compartment. It is especially useful in the detection of enteroceles, and provides a reliable postoperative follow-up tool. Isolated urinary or stool incontinence are not an indication for functional cine MRI, as is the case in patients with equivocal clinical findings. To date it does not allow for real 3D imaging of the pelvic floor or sufficient determination of fascial defects. Discussion: Functional cine MRI of the pelvic floor is a promising new imaging method for the detection of organ descent and prolapse in patients with equivocal clinical findings. The combination of function and morphology allows for an innovative view of the pelvic floor, and thus adds to our understanding of the various interactions of the structures.

  10. Non-invasive assessment of equine muscular function: A case study

    Directory of Open Access Journals (Sweden)

    K.H. Riis

    2013-07-01

    Full Text Available Assessment of muscle function after an injury or during recovery is of great importance in the veterinary field. Accelerometry, bioimpedance analysis and mechanomyography/acoustic myography have been used to assess human muscular problems, but have not been applied to the veterinary clinic. We report the clinical use of these techniques in a 12-year-old Danish Warmblood horse presenting with recurring and shifting lameness. Acoustic myography, assessing both the amplitude and frequency of active muscles, was employed to locate the specific area of muscle injury, the right hip, which exhibited minimal fibre recruitment giving rise to considerable weakness. This specific region was assessed by accelerometry which revealed a normal step interval for the injured leg when compared with the contralateral, but a weaker acceleration and strike force. Finally, an assessment of muscle resistance (R and reactance (Xc using bioimpedance confirmed a regional loss of muscle mass and a loss of cellular integrity compared with the contralateral limb.

  11. Functional MR imaging study of the shoulder

    International Nuclear Information System (INIS)

    Minami, M.; Yoshikawa, K.; Shibuta, H.; Kokubo, T.; Itai, Y.; Iio, M.

    1989-01-01

    This paper presents a functional MR study of the shoulder performed with the positioning in which patients were about to complain of shoulder pain. A 0.064-T permanent MR system was used. The effectiveness of this study was evaluated in the diagnosis of rotator cuff impingement syndrome. Thirteen patients (11 males and two female) were examined prospectively. Three-dimensional Fourier transformation coronal images were obtained with patients' arms at the maximal abduction. They were compared with images obtained while patients' arms were at their sides, chiefly from the viewpoint of severity of impingement and intensity change of the supraspinatus muscle

  12. A 3D machine vision method for non-invasive assessment of respiratory function.

    Science.gov (United States)

    Smith, L N; Smith, M L; Fletcher, M E; Henderson, A J

    2016-06-01

    Respiratory function testing is important for detecting and monitoring illness, however, it is difficult for some patients, such as the young and severely ill, to perform conventional tests that require cooperation and/or patient contact. A new method was developed for non-contact breathing measurement, employing photometric stereo to capture the surface topography of the torso of an unconstrained subject. The surface is integrated to calculate time-dependent volume changes during respiration. The method provides a useful means of continuously measuring volume changes during respiration with high spatial and temporal resolution. The system was tested by comparison with pneumotachometry equipment and a clear periodic signal, of a frequency corresponding to the reference data, was observed. The approach is unique in performing breathing monitoring (with potential diagnostic capability) for unconstrained patients in virtually any lighting conditions (including darkness during sleep) and in a non-contact, unobtrusive (i.e. using imperceptible light) fashion. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Noninvasive Assessment of Tumor Microenvironment Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and 18F-Fluoromisonidazole Positron Emission Tomography Imaging in Neck Nodal Metastases

    International Nuclear Information System (INIS)

    Jansen, Jacobus; Schoeder, Heiko; Lee, Nancy Y.; Wang Ya

    2010-01-01

    Purpose: To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by 18 F-fluoromisonidazole ( 18 F-FMISO) positron emission tomography (PET). Methods and Materials: Thirteen newly diagnosed head-and-neck cancer patients with metastatic neck nodes underwent DCE-MRI and 18 F-FMISO PET imaging before chemotherapy and radiotherapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from 18 F-FMISO PET, the nonparametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with 18 F-FMISO uptake and nodes with no 18 F-FMISO uptake using Mann-Whitney U tests. Results: For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the 18 F-FMISO SUV (ρ = 0.74, p ep (redistribution rate constant) value (ρ = -0.58, p = 0.042) and the 18 F-FMISO SUV. Hypoxic nodes (moderate to severe 18 F-FMISO uptake) had significantly lower median K trans (volume transfer constant) (p = 0.049) and median k ep (p = 0.027) values than did nonhypoxic nodes (no 18 F-FMISO uptake). Conclusion: This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower K trans and k ep values) compared with nonhypoxic nodes.

  14. Potential Applications of Flat-Panel Volumetric CT in Morphologic, Functional Small Animal Imaging

    Directory of Open Access Journals (Sweden)

    Susanne Greschus

    2005-08-01

    Full Text Available Noninvasive radiologic imaging has recently gained considerable interest in basic, preclinical research for monitoring disease progression, therapeutic efficacy. In this report, we introduce flat-panel volumetric computed tomography (fpVCT as a powerful new tool for noninvasive imaging of different organ systems in preclinical research. The three-dimensional visualization that is achieved by isotropic high-resolution datasets is illustrated for the skeleton, chest, abdominal organs, brain of mice. The high image quality of chest scans enables the visualization of small lung nodules in an orthotopic lung cancer model, the reliable imaging of therapy side effects such as lung fibrosis. Using contrast-enhanced scans, fpVCT displayed the vascular trees of the brain, liver, kidney down to the subsegmental level. Functional application of fpVCT in dynamic contrast-enhanced scans of the rat brain delivered physiologically reliable data of perfusion, tissue blood volume. Beyond scanning of small animal models as demonstrated here, fpVCT provides the ability to image animals up to the size of primates.

  15. Magnetic resonance hydrometry: non-invasive quantification of the exocrine pancreatic function

    Energy Technology Data Exchange (ETDEWEB)

    Heverhagen, J.T.; Battmann, A.; Kirsch, M.; Klose, K.J. [Klinik fuer Strahlendiagnostik, Marburg Univ. (Germany); Boehm, D. [Centrum fuer Medizinische Diagnosesysteme und Visualisierung GmbH, Bremen (Germany); Eissele, R. [Klinik fuer Innere Medizin, Klinikum der Philipps Univ. Marburg (Germany); Wagner, H.J. [Klinik fuer Strahlendiagnostik, Marburg Univ. (Germany); Dept. of Radiology, Univ. of Wisconsin, Hospital and Clinics, Madison, WI (United States)

    2002-03-01

    Aims: To show the ability of magnetic resonance hydrometry (MRH) to quantify the pancreatic secretion after secretin stimulation in order to distinguish between physiological excretion and reduced output in chronic pancreatitis. Methods: MRH images were acquired in a 1.0-T-clinical scanner using a body-array coil and a heavily T{sub 2}-weighted standard single-shot TSE sequence. Thirty-one patients (14 male/17 female) who routinely underwent ERCP for suspected choledocholithiasis (n = 22), recurring abdominal pain (n = 1), icterus (n = 6) and suspected pancreatitis (n = 2) were included. During the investigation 1 CU/kg BW secretin were administered intravenously. Secreted volume of fluid, start of secretion, achievement of a plateau of secretion and a combined score of these parameters (MRH score) were assessed and evaluated. Sensitivity and specificity were calculated for these parameters. Results: 27 patients had no pancreatic pathology, and four suffered from chronic pancreatitis. Patients without pancreatic disorders produced a mean pancreatic fluid volume of 183{+-}86 mL, whereas patients with chronic pancreatitis secreted 61{+-}39 mL. Secretion started after a mean time of 95{+-}94 seconds (no pancreatic impairment) and 62{+-}13 seconds (chronic pancreatitis). The MRH score achieved a high accuracy in the detection of chronic pancreatitis. Conclusions: Our study demonstrated the feasibility of measuring pancreatic output by MRH after stimulation with secretin. Moreover, a distinction between normal secretion and patients with chronic pancreatitis is possible. (orig.) [German] Ziel: Ziel war es zu zeigen, dass mittels Magnetresonanz Hydrometrie (MRH) die Sekretion des Pankreas nach Stimulation mit Sekretin exakt zu quantifizieren ist. Die MRH soll erlauben, zwischen der physiologischen Sekretion gesunder Probanden und der eingeschraenkten Sekretion von Patienten mit chronischer Pankreatitis zu unterscheiden. Methoden: MRH-Bilder wurden in einem klinischen 1

  16. Non-invasive optical imaging of eosinophilia during the course of an experimental allergic airways disease model and in response to therapy.

    Directory of Open Access Journals (Sweden)

    M Andrea Markus

    Full Text Available BACKGROUND: Molecular imaging of lung diseases, including asthma, is limited and either invasive or non-specific. Central to the inflammatory process in asthma is the recruitment of eosinophils to the airways, which release proteases and proinflammatory factors and contribute to airway remodeling. The aim of this study was to establish a new approach to non-invasively assess lung eosinophilia during the course of experimental asthma by combining non-invasive near-infrared fluorescence (NIRF imaging with the specific detection of Siglec-F, a lectin found predominantly on eosinophils. METHODOLOGY/PRINCIPAL FINDINGS: An ovalbumin (OVA-based model was used to induce asthma-like experimental allergic airway disease (EAAD in BALB/c mice. By means of a NIRF imager, we demonstrate that 48 h-72 h after intravenous (i.v. application of a NIRF-labeled anti-Siglec-F antibody, mice with EAAD exhibited up to 2 times higher fluorescence intensities compared to lungs of control mice. Furthermore, average lung intensities of dexamethasone-treated as well as beta-escin-treated mice were 1.8 and 2 times lower than those of untreated, EAAD mice, respectively and correlated with the reduction of cell infiltration in the lung. Average fluorescence intensities measured in explanted lungs confirmed the in vivo findings of significantly higher values in inflamed lungs as compared to controls. Fluorescence microscopy of lung cryosections localized the i.v. applied NIRF-labeled anti-Siglec-F antibody predominantly to eosinophils in the peribronchial areas of EAAD lungs as opposed to control lungs. CONCLUSION/SIGNIFICANCE: We show that monitoring the occurrence of eosinophils, a prominent feature of allergic asthma, by means of a NIRF-labeled antibody directed against Siglec-F is a novel and powerful non-invasive optical imaging approach to assess EAAD and therapeutic response in mice over time.

  17. Non-invasive optical imaging of eosinophilia during the course of an experimental allergic airways disease model and in response to therapy.

    Science.gov (United States)

    Markus, M Andrea; Dullin, Christian; Mitkovski, Miso; Prieschl-Grassauer, Eva; Epstein, Michelle M; Alves, Frauke

    2014-01-01

    Molecular imaging of lung diseases, including asthma, is limited and either invasive or non-specific. Central to the inflammatory process in asthma is the recruitment of eosinophils to the airways, which release proteases and proinflammatory factors and contribute to airway remodeling. The aim of this study was to establish a new approach to non-invasively assess lung eosinophilia during the course of experimental asthma by combining non-invasive near-infrared fluorescence (NIRF) imaging with the specific detection of Siglec-F, a lectin found predominantly on eosinophils. An ovalbumin (OVA)-based model was used to induce asthma-like experimental allergic airway disease (EAAD) in BALB/c mice. By means of a NIRF imager, we demonstrate that 48 h-72 h after intravenous (i.v.) application of a NIRF-labeled anti-Siglec-F antibody, mice with EAAD exhibited up to 2 times higher fluorescence intensities compared to lungs of control mice. Furthermore, average lung intensities of dexamethasone-treated as well as beta-escin-treated mice were 1.8 and 2 times lower than those of untreated, EAAD mice, respectively and correlated with the reduction of cell infiltration in the lung. Average fluorescence intensities measured in explanted lungs confirmed the in vivo findings of significantly higher values in inflamed lungs as compared to controls. Fluorescence microscopy of lung cryosections localized the i.v. applied NIRF-labeled anti-Siglec-F antibody predominantly to eosinophils in the peribronchial areas of EAAD lungs as opposed to control lungs. We show that monitoring the occurrence of eosinophils, a prominent feature of allergic asthma, by means of a NIRF-labeled antibody directed against Siglec-F is a novel and powerful non-invasive optical imaging approach to assess EAAD and therapeutic response in mice over time.

  18. Evaluation and Immunohistochemical Qualification of Carbogen-Induced ΔR2* as a Noninvasive Imaging Biomarker of Improved Tumor Oxygenation

    International Nuclear Information System (INIS)

    Baker, Lauren C.J.; Boult, Jessica K.R.; Jamin, Yann; Gilmour, Lesley D.; Walker-Samuel, Simon; Burrell, Jake S.; Ashcroft, Margaret; Howe, Franklyn A.; Griffiths, John R.; Raleigh, James A.; Kogel, Albert J. van der; Robinson, Simon P.

    2013-01-01

    Purpose: To evaluate and histologically qualify carbogen-induced ΔR 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 2 * during air breathing. With the mouse remaining positioned within the magnet bore, the gas supply was switched to carbogen (95% O 2 , 5% CO 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 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 2 were further validated using the Oxylite fiberoptic probe. Results: Carbogen challenge significantly reduced mean tumor R 2 * from 116 ± 13 s −1 to 97 ± 9 s −1 (P 2 * and Δhypoxic fraction (r=0.55, P 2 during carbogen breathing significantly increased from 6.3 ± 2.2 mm Hg to 36.0 ± 7.5 mm Hg (P 2 * as a noninvasive imaging biomarker of increased tumor oxygenation

  19. Venous refocusing for volume estimation: VERVE functional magnetic resonance imaging.

    Science.gov (United States)

    Stefanovic, Bojana; Pike, G Bruce

    2005-02-01

    A novel, noninvasive magnetic resonance imaging-based method for measuring changes in venous cerebral blood volume (CBV(v)) is presented. Venous refocusing for volume estimation (VERVE) exploits the dependency of the spin-spin relaxation rate of deoxygenated blood on the refocusing interval. Interleaved CPMG EPI acquisitions following a train of either tightly or sparsely spaced hard refocusing pulses (every 3.7 or 30 msec, respectively) at matched echo time were used to isolate the blood signal while minimizing the intravascular blood oxygenation level dependent (BOLD) signal contribution. The technique was employed to determine the steady-state increase in the CBV(v) in the visual cortex (VC) in seven healthy adult volunteers during flickering checkerboard photic stimulation. A functional activation model and a set of previously collected in vitro human whole blood relaxometry data were used to evaluate the intravascular BOLD effect on the VERVE signal. The average VC venous blood volume change was estimated to be 16 +/- 2%. This method has the potential to provide efficient and continuous monitoring of venous cerebral blood volume, thereby enabling further exploration of the mechanism underlying BOLD signal changes upon physiologic, pathophysiologic, and pharmacologic perturbations.

  20. Imaging visual function of the human brain

    International Nuclear Information System (INIS)

    Marg, E.

    1988-01-01

    Imaging of human brain structure and activity with particular reference to visual function is reviewed along with methods of obtaining the data including computed tomographic (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET). The literature is reviewed and the potential for a new understanding of brain visual function is discussed. PET is reviewed from basic physical principles to the most recent visual brain findings with oxygen-15. It is shown that there is a potential for submillimeter localization of visual functions with sequentially different visual stimuli designed for the temporal separation of the responses. Single photon emission computed tomography (SPECT), a less expensive substitute for PET, is also discussed. MRS is covered from basic physical principles to the current state of the art of in vivo biochemical analysis. Future possible clinical applications are discussed. Improved understanding of the functional neural organization of vision and brain will open a window to maps and circuits of human brain function.119 references

  1. Electroencephalographic imaging of higher brain function

    Science.gov (United States)

    Gevins, A.; Smith, M. E.; McEvoy, L. K.; Leong, H.; Le, J.

    1999-01-01

    High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

  2. Evaluation of cerebral blood flow, cerebral metabolism and cerebral function by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tanaka, Chuzo; Higuchi, Toshihiro; Umeda, Masahiro; Naruse, Shoji; Horikawa, Yoshiharu; Ueda, Satoshi; Furuya, Seiichi.

    1995-01-01

    The magnetic resonance (MR) method has the unique potentiality of detecting cerebral metabolites, cerebral blood flow and brain functions in a noninvasive fashion. We have developed several MR techniques to detect these cerebral parameters with the use of clinical MRI scanners. By modifying the MR spectroscopy (MRS) technique, both 31 P- and 1 H-MRS data can be obtained from multiple, localized regions (multi-voxel method) of the brain, and the distribution of each metabolite in the brain can be readily visualized by metabolite mapping. The use of diffusion weighted images (DWI) permits visualization of the anisotropy of water diffusion in white matter, and based on the difference of diffusion coefficiency, the differential diagnosis between epidermoid tumor and arachnoid cyst can be made. By employing dynamic-MRI (Dyn-MRI) with Gd-DTPA administration, it is possible to examine the difference in blood circulation between brain tumor tissue and normal tissue, as well as among different types of brain tumors. By using magnetization transfer contrast (MTC) imaging, it has become possible to detect brain tumors, and with a small dose of Gd-DTPA, to visualize the vascular system. Functional MRI (fMRI) visualizes the activated brain by using conventional gradient echo technique on conventional MRI scanners. This method has the unique characteristic of detecting a brain function with high spatial and temporal resolution by using the intrinsic substance. Moreover, the localization of motor and sensory areas was detected by noninvasive means within few minutes. The fMRI procedure will be used in the future to analyze the higher and complex brain functions. In conclusion, multi-modality MR is a powerful technique that is useful for investigating the pathogenesis of many diseases, and provides a noninvasive analytic modality for studying brain function. (author)

  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. Functional Magnetic Resonance Imaging for Language Mapping in Temporal Lobe Epilepsy

    Directory of Open Access Journals (Sweden)

    An Wang

    2012-01-01

    Full Text Available Functional magnetic resonance imaging (fMRI is a noninvasive technique that is increasingly used to understand the cerebral cortical networks and organizations. In this paper, we describe the role of fMRI for mapping language networks in the presurgical workup of patients with medically intractable temporal lobe epilepsy (TLE. Studies comparing fMRI with the intracarotid sodium amobarbital (Wada test and fMRI with intraoperative cortical stimulation mapping for language lateralization and/or localization in medically intractable TLE are discussed.

  5. 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.

  6. 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.

  7. 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.

  8. Functional MRI using regularized parallel imaging acquisition.

    Science.gov (United States)

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M; Belliveau, John W; Wald, Lawrence L; Kwong, Kenneth K

    2005-08-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions. 2005 Wiley-Liss, Inc

  9. Multiple image x-radiography for functional lung imaging

    Science.gov (United States)

    Aulakh, G. K.; Mann, A.; Belev, G.; Wiebe, S.; Kuebler, W. M.; Singh, B.; Chapman, D.

    2018-01-01

    Detection and visualization of lung tissue structures is impaired by predominance of air. However, by using synchrotron x-rays, refraction of x-rays at the interface of tissue and air can be utilized to generate contrast which may in turn enable quantification of lung optical properties. We utilized multiple image radiography, a variant of diffraction enhanced imaging, at the Canadian light source to quantify changes in unique x-ray optical properties of lungs, namely attenuation, refraction and ultra small-angle scatter (USAXS or width) contrast ratios as a function of lung orientation in free-breathing or respiratory-gated mice before and after intra-nasal bacterial endotoxin (lipopolysaccharide) instillation. The lung ultra small-angle scatter and attenuation contrast ratios were significantly higher 9 h post lipopolysaccharide instillation compared to saline treatment whereas the refraction contrast decreased in magnitude. In ventilated mice, end-expiratory pressures result in an increase in ultra small-angle scatter contrast ratio when compared to end-inspiratory pressures. There were no detectable changes in lung attenuation or refraction contrast ratio with change in lung pressure alone. In effect, multiple image radiography can be applied towards following optical properties of lung air-tissue barrier over time during pathologies such as acute lung injury.

  10. Using non-invasive molecular spectroscopic techniques to detect unique aspects of protein Amide functional groups and chemical properties of modeled forage from different sourced-origins

    Science.gov (United States)

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-01

    The non-invasive molecular spectroscopic technique-FT/IR is capable to detect the molecular structure spectral features that are associated with biological, nutritional and biodegradation functions. However, to date, few researches have been conducted to use these non-invasive molecular spectroscopic techniques to study forage internal protein structures associated with biodegradation and biological functions. The objectives of this study were to detect unique aspects and association of protein Amide functional groups in terms of protein Amide I and II spectral profiles and chemical properties in the alfalfa forage (Medicago sativa L.) from different sourced-origins. In this study, alfalfa hay with two different origins was used as modeled forage for molecular structure and chemical property study. In each forage origin, five to seven sources were analyzed. The molecular spectral profiles were determined using FT/IR non-invasive molecular spectroscopy. The parameters of protein spectral profiles included functional groups of Amide I, Amide II and Amide I to II ratio. The results show that the modeled forage Amide I and Amide II were centered at 1653 cm- 1 and 1545 cm- 1, respectively. The Amide I spectral height and area intensities were from 0.02 to 0.03 and 2.67 to 3.36 AI, respectively. The Amide II spectral height and area intensities were from 0.01 to 0.02 and 0.71 to 0.93 AI, respectively. The Amide I to II spectral peak height and area ratios were from 1.86 to 1.88 and 3.68 to 3.79, respectively. Our results show that the non-invasive molecular spectroscopic techniques are capable to detect forage internal protein structure features which are associated with forage chemical properties.

  11. Infrared Imaging System for Studying Brain Function

    Science.gov (United States)

    Mintz, Frederick; Mintz, Frederick; Gunapala, Sarath

    2007-01-01

    A proposed special-purpose infrared imaging system would be a compact, portable, less-expensive alternative to functional magnetic resonance imaging (fMRI) systems heretofore used to study brain function. Whereas a typical fMRI system fills a large room, and must be magnetically isolated, this system would fit into a bicycle helmet. The system would include an assembly that would be mounted inside the padding in a modified bicycle helmet or other suitable headgear. The assembly would include newly designed infrared photodetectors and data-acquisition circuits on integrated-circuit chips on low-thermal-conductivity supports in evacuated housings (see figure) arranged in multiple rows and columns that would define image coordinates. Each housing would be spring-loaded against the wearer s head. The chips would be cooled by a small Stirling Engine mounted contiguous to, but thermally isolated from, the portions of the assembly in thermal contact with the wearer s head. Flexible wires or cables for transmitting data from the aforementioned chips would be routed to an integrated, multichannel transmitter and thence through the top of the assembly to a patch antenna on the outside of the helmet. The multiple streams of data from the infrared-detector chips would be sent to a remote site, where they would be processed, by software, into a three-dimensional display of evoked potentials that would represent firing neuronal bundles and thereby indicate locations of neuronal activity associated with mental or physical activity. The 3D images will be analogous to current fMRI images. The data would also be made available, in real-time, for comparison with data in local or internationally accessible relational databases that already exist in universities and research centers. Hence, this system could be used in research on, and for the diagnosis of response from the wearer s brain to physiological, psychological, and environmental changes in real time. The images would also be

  12. Noninvasive Assessment ofIDHMutational Status in World Health Organization Grade II and III Astrocytomas Using DWI and DSC-PWI Combined with Conventional MR Imaging.

    Science.gov (United States)

    Xing, Z; Yang, X; She, D; Lin, Y; Zhang, Y; Cao, D

    2017-06-01

    Isocitrate dehydrogenase ( IDH ) has been shown to have both diagnostic and prognostic implications in gliomas. The purpose of this study was to examine whether DWI and DSC-PWI combined with conventional MR imaging could noninvasively predict IDH mutational status in World Health Organization grade II and III astrocytomas. We retrospectively reviewed DWI, DSC-PWI, and conventional MR imaging in 42 patients with World Health Organization grade II and III astrocytomas. Minimum ADC, relative ADC, and relative maximum CBV values were compared between IDH -mutant and wild-type tumors by using the Mann-Whitney U test. Receiver operating characteristic curve and logistic regression were used to assess their diagnostic performances. Minimum ADC and relative ADC were significantly higher in IDH -mutated grade II and III astrocytomas than in IDH wild-type tumors ( P IDH mutation provided a sensitivity, specificity, positive predictive value, and negative predictive value of 100.0%, 60.9%, 85.6%, and 100.0%, respectively. A combination of DWI, DSC-PWI, and conventional MR imaging for the identification of IDH mutations resulted in a sensitivity, specificity, positive predictive value, and negative predictive value of 92.3%, 91.3%, 96.1%, and 83.6%. A combination of conventional MR imaging, DWI, and DSC-PWI techniques produces a high sensitivity, specificity, positive predictive value, and negative predictive value for predicting IDH mutations in grade II and III astrocytomas. The strategy of using advanced, semiquantitative MR imaging techniques may provide an important, noninvasive, surrogate marker that should be studied further in larger, prospective trials. © 2017 by American Journal of Neuroradiology.

  13. 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.

  14. Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives.

    Science.gov (United States)

    Schönfeldt-Lecuona, Carlos; Lefaucheur, Jean-Pascal; Lepping, Peter; Liepert, Joachim; Connemann, Bernhard J; Sartorius, Alexander; Nowak, Dennis A; Gahr, Maximilian

    2016-01-01

    Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale-Improvement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of

  15. Non-invasive Brain Stimulation in Conversion (functional Weakness and Paralysis: A Systematic Review and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Carlos eSchönfeldt-Lecuona

    2016-03-01

    Full Text Available Conversion (functional limb weakness or paralysis (FW can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioural approach combined with a motor learning program. Non-invasive brain stimulation (NIBS methods, such as electroconvulsive therapy (ECT and transcranial magnetic stimulation (TMS have been used in the past few decades to treat FW.In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale – Improvement scores to describe approximate changes of FW symptoms.We identified two articles (case reports with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (rTMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. 54 out of 75 identified patients (72% had a CGI-I score of 1 (very much improvement, 13 (17% a score of 2 (much improvement, 5 (7% a score of 3 (minimally improved, and 3 (5% remained unchanged (CGI-I = 4. In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2, but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW

  16. NON-INVASIVE METHODS OF THE WORK-UP FOR ASSESSMENT OF MORPHOLOGIC AND FUNCTIONAL STATE OF THE SIGMOID WALL

    Directory of Open Access Journals (Sweden)

    A. E. Mashkov

    2015-01-01

    Full Text Available Background: Prolonged colonic congestion in children with chronic constipation and dolichosigma are characterized  by a permanent imbalance of gut microflora, secondary inflammation and degeneration of the sigmoid wall. There is plenty of research papers on the optic non-invasive diagnostics in medicine, based on spectrophotometry and laser spectral analysis. Aim: To study morphologic and functional state  of the sigmoid wall for detection of inflammation  and  degeneration in the  sigmoid  wall and  optimization  of treatment of children with dolichosigma  and long-standing constipation. Materials and methods: From 2009 to 2014, 30 children with dolichosigma  were seen in the Department of Pediatric surgery of MONIKI. All patients  were  hospitalized  after unsuccessful conservative  treatment in in-patient  clinics of the Moscow Region. The children underwent a set of investigations  for objective assessment of degree of the secondary  inflammatory and degenerative abnormalities  in the sigmoid wall, such as microbiological assessment, cytological assessment and fluorescent  diagnostics.  Results:  There  was  no   caused  by dolichosigma. It maintains  chronic inflammation  and  may play an indirect  role in abnormalities  of gut  motor  function. Inflammatory and  degenerative abnormalities  were  confirmed by a cytological investigation  of wall-adjacent biopsy of the  sigma. The results of the  complex assessment showed  moderate inflammation  and degeneration in the  sigmoid wall in 20 children; subsequent conservative treatment of chronic colostasis was effective. Ten children had advanced secondary inflammatory and degenerative abnormalities of the  sigmoid  wall, with high  levels of elastin and collagen in the colon wall. Surgery was performed in 6 children with the highest degree of fibrous transformation of the sigma. Conclusion: Complex assessment of the sigmoid wall, including

  17. Imaging of lung function using synchrotron radiation computed tomography: What's new?

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, Sam [Universite de Picardie Jules Verne, Departement de Physiologie, DMAG EA 3901, 3 Rue des Louvels, 80036 Amiens Cedex 1 (France)], E-mail: Bayat.Sam@chu-amiens.fr; Porra, Liisa [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: porra@esrf.fr; Suhonen, Heikki [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: heikki.suhonen@helsinki.fi; Janosi, Tibor [Geneva Children' s Hospital, University Hospitals of Geneva and University of Geneva, Geneva (Switzerland)], E-mail: janosit@dmi.u-szeged.hu; Strengell, Satu [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: skstreng@mappi.helsinki.fi; Habre, Walid [Geneva Children' s Hospital, University Hospitals of Geneva and University of Geneva, Geneva (Switzerland)], E-mail: Walid.Habre@hcuge.ch; Petak, Ferenc [Department of Department of Medical Informatics and Engineering, University of Szeged, 6720 Szeged, Koranyi fasor 9 (Hungary)], E-mail: petak@dmi.szote.u-szeged.hu; Hantos, Zoltan [Department of Department of Medical Informatics and Engineering, University of Szeged, 6720 Szeged, Koranyi fasor 9 (Hungary)], E-mail: hantos@dmi.u-szeged.hu; Suortti, Pekka [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: Pekka.Suortti@helsinki.fi; Sovijaervi, Anssi [Departments of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, POB 340, FIN-00029 HUS, Helsinki (Finland)], E-mail: anssi.sovijarvi@hus.fi

    2008-12-15

    There is a growing interest in imaging techniques as non-invasive means of quantitatively measuring regional lung structure and function. Abnormalities in lung ventilation due to alterations in airway function such as those observed in asthma and COPD are highly heterogeneous, and experimental methods to study this heterogeneity are crucial for better understanding of disease mechanisms and drug targeting strategies. In severe obstructive diseases requiring mechanical ventilation, the optimal ventilatory strategy to achieve recruitment of poorly ventilated lung zones remains a matter of considerable debate. We have used synchrotron radiation computed tomography (SRCT) for the in vivo study of regional lung ventilation and airway function. This imaging technique allows direct quantification of stable Xenon (Xe) gas used as an inhaled contrast agent using K-edge subtraction imaging. Dynamics of Xe wash-in can be used to calculate quantitative maps of regional specific lung ventilation. More recently, the development of Spiral-CT has allowed the acquisition of 3D images of the pulmonary bronchial tree and airspaces. This technique gives access to quantitative measurements of regional lung volume, ventilation, and mechanical properties. Examples of application in an experimental model of allergic asthma and in imaging lung recruitment as a function of mechanical ventilation parameters will be presented. The future orientations of this tecnique will be discussed.

  18. 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.)

  19. Magnetic Targeting and Delivery of Drug-Loaded SWCNTs Theranostic Nanoprobes to Lung Metastasis in Breast Cancer Animal Model: Noninvasive Monitoring Using Magnetic Resonance Imaging.

    Science.gov (United States)

    Al Faraj, Achraf; Shaik, Asma Sultana; Halwani, Rabih; Alfuraih, Abdulrahman

    2016-06-01

    In this study, we aimed to develop novel therapeutic and diagnostic approaches by improving the targeting of doxorubicin-loaded single-walled carbon nanotubes (SWCNTs) to metastatic regions, and monitor their preferential homing and enhanced therapeutic effect using noninvasive free-breathing magnetic resonance imaging (MRI) and bioluminescence imaging. High-energy flexible magnets were specifically positioned over the metastatic tumor sites in the lungs. SWCNTs biodistribution, tumor progression, and subsequent treatment efficiency were assessed following administration of the magnetically attracted doxorubicin-loaded anti-CD105 conjugated nanocarriers. The use of high-energy magnets offered improved theranostic effect of doxorubicin-loaded nanocarriers, by magnetically targeting them towards metastatic tumor sites in the lungs. MRI allowed sensitive monitoring of nanocarriers biodistribution in the abdominal organs, their preferential homing towards the metastatic sites, and their enhanced therapeutic effect. Combination of noninvasive MRI to localize sensitively the tumor sites, with specific positioning of magnets that can enhance the magnetic targeting of nanocarriers, allowed increasing the treatment efficiency.

  20. Clinical application of functional magnetic resonance imaging

    CERN Document Server

    Alwatban, A Z W

    2002-01-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a ...

  1. 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

  2. Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

    Science.gov (United States)

    Yao, Junjie; Xia, Jun; Maslov, Konstantin I.; Nasiriavanaki, Mohammadreza; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

    2012-01-01

    We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood-brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively decoupled by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area had a clear vascular pattern and spread wider than the somatosensory region. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism. PMID:22940116

  3. Comparison of exercise capacity with resting left ventricular function evaluated by various non-invasive methods in patients with old myocardial infarction

    International Nuclear Information System (INIS)

    Yamabe, Hiroshi; Kobayashi, Katsuya; Tajiri, Eiichi; Hayakawa, Masanori; Minamiji, Katsumi

    1982-01-01

    The relationship between exercise capacity and resting left ventricular function assessed by several non-invasive methods in patients with old myocardial infarction was investigated. Subjects were 25 male patients whose endpoint was either dyspnea or general fatigue at the symptom-limited maximal graded treadmill exercise test according to Bruce protocol. The indices obtained by non-invasive cardiac examinations included left ventricular fractional shortening (% FS), scintigraphic infact size (% SIS) by 201 Tl myocardial scintigraphy and PEP/ET. A significant correlation of exercise duration with % FS (r = 0.67, p < 0.001) or with % SIS (r = -0.55, p < 0.02) indicated that the more impaired resting left ventricular function, the more was decreased exercise capacity. Also, a significant correlation of systolic blood pressure at the endpoint in exercise test with % FS (r = 0.58, p < 0.005) or with % SIS (r = 0.69, p < 0.001) indicated that inadequate blood pressure response might be partially attributed to impaired left ventricular function during exercise. The response of heart rate at the Bruce protocol stage I correlated with % FS (r = -0.67, p < 0.001) and with % SIS (r = 0.53, p < 0.02), respectively. These findings may be interpreted as chronotropic compensatory mechanism for limited stroke volume during exercise in patients with impaired left ventricular function. Thus, it was concluded that resting left ventricular function assessed by non-invasive cardiac examinations may predict exercise capacity prior to the test to some extent. These informations can be utilized for the decision of the planning at cardiac rehabilitation and also for the guidance in daily activities. (J.P.N.)

  4. 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.

  5. Teleseismic receiver functions imaging of Siberia

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Thybo, Hans; Artemieva, Irina

    2014-01-01

    We map the lithosphere in Siberia by using the available broadband seismic data for calculation of Ps- and Sp-wave receiver functions (RF). RFs show converted waves from discontinuities in the vicinity of the seismic stations. The main objective is to image the Moho and upper mantle discontinuities......, including the lithosphere-asthenosphere boundary (LAB) beneath the study area. We construct the RF using the LQT method (Vinnik, 1977; Kind et al. 1995) in the version by Yuan et al. (1997). Rotation of ray coordinates uses the incidence angles predicted by the AK135 velocity model. This decomposes the wave...... by high-frequency S-RFs. Teleseismic converted Ps waves have higher frequency content (0.5–2 Hz) than Sp, which have an upper frequency of 0.1–0.2 Hz, and therefore Ps have about an order of magnitude better resolving power than Sp. The converted Sp-wave rarely resolve intracrustal structure, but can...

  6. Functional Magnetic Resonance Imaging in Consumer Research

    DEFF Research Database (Denmark)

    Reimann, Martin; Schilke, Oliver; Weber, Bernd

    2011-01-01

    of prior fMRI research related to consumer behavior and highlights the features that make fMRI an attractive method for consumer and marketing research. The authors discuss advantages and limitations and illustrate the proposed procedures with an applied study, which investigates loss aversion when buying......Although the field of psychology is undergoing an immense shift toward the use of functional magnetic resonance imaging (fMRI), the application of this methodology to consumer research is relatively new. To assist consumer researchers in understanding fMRI, this paper elaborates on the findings...... and selling a common product. Results reveal a significantly stronger activation in the amygdala while consumers estimate selling prices versus buying prices, suggesting that loss aversion is associated with the processing of negative emotion. © 2011 Wiley Periodicals, Inc....

  7. Accuracy of real time noninvasive temperature measurements using magnetic resonance thermal imaging in patients treated for high grade extremity soft tissue sarcomas

    Science.gov (United States)

    Craciunescu, Oana I.; Stauffer, Paul R.; Soher, Brian J.; Wyatt, Cory R.; Arabe, Omar; Maccarini, Paolo; Das, Shiva K.; Cheng, Kung-Shan; Wong, Terence Z.; Jones, Ellen L.; Dewhirst, Mark W.; Vujaskovic, Zeljko; MacFall, James R.

    2009-01-01

    Purpose: To establish accuracy of real time noninvasive temperature measurements using magnetic resonance thermal imaging in patients treated for high grade extremity soft tissue sarcomas. Methods: Protocol patients with advanced extremity sarcomas were treated with external beam radiation therapy and hyperthermia. Invasive temperature measures were compared to noninvasive magnetic resonance thermal imaging (MRTI) at 1.5 T performed during hyperthermia. Volumetric temperature rise images were obtained using the proton resonance frequency shift (PRFS) technique during heating in a 140 MHz miniannular phased array applicator. MRTI temperature changes were compared to invasive measurements of temperature with a multisensor fiber optic probe inside a #15 g catheter in the tumor. Since the PRFS technique is sensitive to drifts in the primary imaging magnetic field, temperature change distributions were corrected automatically during treatment using temperature-stable reference materials to characterize field changes in 3D. The authors analyzed MRT images and compared, in evaluable treatments, MR-derived temperatures to invasive temperatures measured in extremity sarcomas. Small regions of interest (ROIs) were specified near each invasive sensor identified on MR images. Temperature changes in the interstitial sensors were compared to the corresponding ROI PRFS-based temperature changes over the entire treatment and over the steady-state period. Nonevaluable treatments (motion∕imaging artifacts, noncorrectable drifts) were not included in the analysis. Results: The mean difference between MRTI and interstitial probe measurements was 0.91 °C for the entire heating time and 0.85 °C for the time at steady state. These values were obtained from both tumor and normal tissue ROIs. When the analysis is done on just the tumor ROIs, the mean difference for the whole power on time was 0.74 °C and during the period of steady state was 0.62 °C. Conclusions: The data show that

  8. Measurement of abdominal muscle thickness using M-mode ultrasound imaging during functional activities.

    Science.gov (United States)

    Bunce, Steve M; Hough, Alan D; Moore, Ann P

    2004-02-01

    Ultrasound imaging has been previously utilized in the measurement of muscle thickness and cross-sectional area in research studies, and advocated as a clinical biofeedback tool in the rehabilitation of transversus abdominis function following episodes of low back pain. This paper describes how the thickness of the abdominal muscles can be quantified with a new measurement technique using M-mode ultrasound. The technique uses a custom-made transducer holder that facilitates measurement of muscle thickness changes during functional activity. Limitations of the technique and potential future applications are discussed. The M-mode ultrasound technique may provide an effective method for the non-invasive measurement of abdominal muscle thickness during functional activities.

  9. Gingival blood flow under total combs by functional pressure evaluated with laser-Doppler flowmetry, a non-invasive method of blood flow measurement

    International Nuclear Information System (INIS)

    Hengl, St.

    1996-09-01

    Gingival blood flow under total-combs by functional pressure evaluated with Laser-Doppler Flowmetry, a non-invasive method of blood flow measurement. Microcirculation of gum's capillary system can be measured non-invasive by Laser-Doppler-Flowmetry (LDF). Circulation, defined by the number of floating erythrocytes per unit of time, is measured by a fibro-optical Laser-Doppler-Flowmetry. The task was to examine, if there is any change of gum's circulation during strain and relief. Circulation on defined measurepoints, divided on the four quadrants, was determined among maximal strain and subsequent relief, on one probationer (complete denture bearer). Before every measure session systemic pressure was taken. LDF-value was taken on top of jaw-comb, in doing so, to get reproducible result and a satisfying fixation of the probe, there was made an artificial limb of the upper and lower comb. In the upper comb a dynamometer-box, which determined minimal and maximal comb pressure, was integrated. The received results of the LDF-measurement, expressed as perfusion units (PU) were lower under applied pressure than by pressure points more distant. Hyperemia, resulting during relief, seemed the more intense, the less perfusion was before. This new, non-invasive kind of circulation measurement seems to be quite predestined to be used for gingival diagnostic under artificial limb in the future. (author)

  10. Non-Invasive Imaging of the Aortic Root : towards optimal evaluation and sizing of stented (tissue engineered) heart valves

    NARCIS (Netherlands)

    de Heer, L.M.

    2012-01-01

    In Part I of this thesis the application of multidetector-row computed tomography (MDCT) (Chapter 2) and magnetic resonance imaging (MRI) (Chapter 3) in the imaging of the aortic root has been investigated. Imaging of the stenotic aortic root by echocardiography, MDCT or MRI is relevant for TAVI.

  11. Validation of noninvasive indices of global systolic function in patients with normal and abnormal loading conditions: a simultaneous echocardiography pressure-volume catheterization study.

    Science.gov (United States)

    Yotti, Raquel; Bermejo, Javier; Benito, Yolanda; Sanz-Ruiz, Ricardo; Ripoll, Cristina; Martínez-Legazpi, Pablo; del Villar, Candelas Pérez; Elízaga, Jaime; González-Mansilla, Ana; Barrio, Alicia; Bañares, Rafael; Fernández-Avilés, Francisco

    2014-01-01

    Noninvasive indices based on Doppler echocardiography are increasingly used in clinical cardiovascular research to evaluate left ventricular global systolic chamber function. Our objectives were to clinically validate ultrasound-based methods of global systolic chamber function to account for differences between patients in conditions of abnormal load, and to assess their sensitivity to load confounders. Twenty-seven patients (8 dilated cardiomyopathy, 10 normal ejection fraction, and 9 end-stage liver disease) underwent simultaneous echocardiography and left heart catheterization with pressure-conductance instrumentation. The reference index, maximal elastance (Emax), was calculated from pressure-volume loop data obtained during acute inferior vena cava occlusion. A wide range of values were observed for left ventricular systolic chamber function (Emax: 2.8±1.0 mm Hg/mL), preload, and afterload. Among the noninvasive indices tested, the peak ejection intraventricular pressure difference showed the best correlation with Emax (R=0.75). A significant but weaker correlation with Emax was observed for ejection fraction (R=0.41), midwall fractional shortening (R=0.51), global circumferential strain (R=-0.53), and strain rate (R=-0.46). Longitudinal strain and strain rate failed to correlate with Emax, as did noninvasive single-beat estimations of this index. Principal component and multiple regression analyses demonstrated that peak ejection intraventricular pressure difference was less sensitive to load, whereas ejection fraction and longitudinal strain and strain rate were heavily influenced by afterload. Current ultrasound methods have limited accuracy to characterize global left ventricular systolic chamber function in a given patient. The Doppler-derived peak ejection intraventricular pressure difference should be preferred for this purpose because it best correlates with the reference index and is more robust in conditions of abnormal load.

  12. Preliminary pilot fMRI study of neuropostural optimization with a noninvasive asymmetric radioelectric brain stimulation protocol in functional dysmetria

    Directory of Open Access Journals (Sweden)

    Mura M

    2012-04-01

    Full Text Available Marco Mura1, Alessandro Castagna2, Vania Fontani2, Salvatore Rinaldi21Institute of Radiology, University of Cagliari, 2Rinaldi Fontani Institute – Department of Neuro Psycho Physical Optimization, Florence, ItalyPurpose: This study assessed changes in functional dysmetria (FD and in brain activation observable by functional magnetic resonance imaging (fMRI during a leg flexion-extension motor task following brain stimulation with a single radioelectric asymmetric conveyer (REAC pulse, according to the precisely defined neuropostural optimization (NPO protocol.Population and methods: Ten healthy volunteers were assessed using fMRI conducted during a simple motor task before and immediately after delivery of a single REAC-NPO pulse. The motor task consisted of a flexion-extension movement of the legs with the knees bent. FD signs and brain activation patterns were compared before and after REAC-NPO.Results: A single 250-millisecond REAC-NPO treatment alleviated FD, as evidenced by patellar asymmetry during a sit-up motion, and modulated activity patterns in the brain, particularly in the cerebellum, during the performance of the motor task.Conclusion: Activity in brain areas involved in motor control and coordination, including the cerebellum, is altered by administration of a REAC-NPO treatment and this effect is accompanied by an alleviation of FD.Keywords: motor behavior, motor control, cerebellum, dysmetria, functional dysmetria, fluctuating asymmetry

  13. Clinical application of functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Alwatban, Adnan Z.W

    2002-07-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the author except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a transtympanic electrode implanted onto the surface of the cochlea. This approach would however, result in electromotive forces (EMFs) being induced by the time varying magnetic field, which would lead to current flow and heating, as well as deflection of the metallic electrode within the static magnetic field, and image distortion due to the magnetic susceptibility difference. A gold-plated tungsten electrode with a zero magnetic susceptibility was developed to avoid image distortion. Used with carbon leads and a carbon reference pad, it enabled safe, distortion-free fMRI studies of deaf subjects. The study revealed activation of the primary auditory cortex. This fMRI procedure can be used to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for pre-operative assessment of candidates for cochlear implantation. Glucose is the energy source on which the function of the human brain is entirely dependent. Failure to

  14. Clinical application of functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Alwatban, Adnan Z.W.

    2002-01-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the author except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a transtympanic electrode implanted onto the surface of the cochlea. This approach would however, result in electromotive forces (EMFs) being induced by the time varying magnetic field, which would lead to current flow and heating, as well as deflection of the metallic electrode within the static magnetic field, and image distortion due to the magnetic susceptibility difference. A gold-plated tungsten electrode with a zero magnetic susceptibility was developed to avoid image distortion. Used with carbon leads and a carbon reference pad, it enabled safe, distortion-free fMRI studies of deaf subjects. The study revealed activation of the primary auditory cortex. This fMRI procedure can be used to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for pre-operative assessment of candidates for cochlear implantation. Glucose is the energy source on which the function of the human brain is entirely dependent. Failure to

  15. A brush stimulator for functional brain imaging.

    Science.gov (United States)

    Jousmäki, V; Nishitani, N; Hari, R

    2007-12-01

    To describe a novel non-magnetic hand-held device to stimulate various parts of the skin and to evaluate its performance in magnetoencephalographic (MEG) recordings. The hand-held part of the device consists of an optic fiber bundle that forms a small brush. Half of the fibers emit modulated red light and the other half detect the reflected light from the skin so that the brush-to-skin contact is detected by means of reflectance. Light tapping of the back of the hand at the innervation area of the radial nerve elicited clear responses in all 10 subjects studied, with the main deflections peaking 40-70 ms after the stimulus. The earliest responses, obtained with a higher number of averaged trials, peaked 27-28 ms after the tap to the left hand dorsum. Source analysis of the MEG signals indicated neuronal sources at the primary somatosensory (SI) cortex, with a clear somatotopical order for face vs. hand. The device seems feasible for both MEG and functional magnetic resonance imaging experiments to address functional anatomy of the human somatosensory system with a real-life like stimulation. Non-magnetic and artefact-free tactile stimulator with a selective stimulus offers new possibilities for experimental designs to study the human mechanoreceptor system.

  16. Functional hepatobiliary MR imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Tamrazi, Anobel; Vasanawala, Shreyas S. [Stanford University, Department of Radiology, Stanford, CA (United States)

    2011-10-15

    Clinical application efforts for the hepatocyte-specific MRI contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) have mainly been directed toward detection and characterization of various hepatic masses in the adult population. Here we report our initial experience with Gd-EOB-DTPA for evaluating congenital and acquired hepatobiliary pathologies in the pediatric population. Twenty-one consecutive children receiving Gd-EOB-DTPA for functional hepatobiliary evaluation at our institution were retrospectively identified with IRB approval. The use of Gd-EOB-DTPA was classified in each case as definite, potential, or no clinical utility, focusing on the clinical value gained beyond traditional noncontrast fluid-sensitive MR cholangiopancreatography (FS-MRCP) and other imaging modalities. Definite added value of Gd-EOB-DTPA was found in 12 patients, with potential value in 4 patients, and no value in 5 patients. Benefit was seen in cases of iatrogenic and non-iatrogenic biliary strictures, perihepatic fluid collections for biliary leak, hepatobiliary dysfunction in the absence of hyperbilirubinemia, and in the functional exclusion of cystic duct occlusion that can be seen in acute cholecystitis. This is the first reported series of children with Gd-EOB-DTPA and this early work suggests potential pediatric applications. (orig.)

  17. A fast analysis method for non-invasive imaging of blood flow in individual cerebral arteries using vessel-encoded arterial spin labelling angiography

    Science.gov (United States)

    Chappell, Michael A.; Okell, Thomas W.; Payne, Stephen J.; Jezzard, Peter; Woolrich, Mark W.

    2012-01-01

    Arterial spin labelling (ASL) MRI offers a non-invasive means to create blood-borne contrast in vivo for dynamic angiographic imaging. By spatial modulation of the ASL process it is possible to uniquely label individual arteries over a series of measurements, allowing each to be separately identified in the resulting angiographic images. This separation requires appropriate analysis for which a general Bayesian framework has previously been proposed. Here this framework is adapted for clinical dynamic angiographic imaging. This specifically addresses the issues of computational speed of the algorithm and the robustness required to deal with real patient data. An algorithm is proposed that can incorporate planning information about the arteries being imaged whilst adapting for subsequent patient movement. A fast maximum a posteriori solution is adopted and shown to be only marginally less accurate than Monte Carlo sampling under simulation. The final algorithm is demonstrated on in vivo data with analysis on a time scale of the order of 10 min, from both a healthy control and a patient with a vertebro-basilar occlusion. PMID:22322066

  18. Three-dimensional reconstruction of functional brain images

    International Nuclear Information System (INIS)

    Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao

    1999-01-01

    We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

  19. Familial Essential Tremor Studied With Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Hernandez, A.; Salgado, P.; Gil, A.; Barrios, F. A.

    2003-09-01

    Functional Magnetic Resonance Imaging has become an important analytical tool to study neurodegenerative diseases. We applied the EPI-BOLD functional Magnetic Resonance Imaging technique to acquire functional images of patients with familial essential tremor (FET) disorder and healthy control volunteers, during a motor task activity. Functional and anatomic images were used to produce the brain activation maps of the patients and volunteers. These functional maps of the primary somatosensorial and motor cortexes of patients and control subjects were compared for functional differences per subject. The averaged functional brain images of eight of each case were acquired were, it can be clearly observed the differences in active zones. The results presented in this work show that there are differences in the functional maps during motor task activation between control subjects and FET patients suggesting a cerebral functional reorganization that can be mapped with BOLD-fMRI.

  20. HeNe laser (633 nm)-coupled confocal microscope allows simulating magnetic resonance imaging/computed tomography scan of the brain and eye: a noninvasive optical approach applicable to small laboratory animals.

    Science.gov (United States)

    Zheng, Ping-Pin; Romme, Edwin; van der Spek, Peter J; Dirven, Clemens M F; Willemsen, Rob; Kros, Johan M

    2011-06-01

    Magnetic resonance imaging (MRI) and computed tomography (CT) are noninvasive medical imaging techniques used for the detailed visualization of internal organs of the human body. Because CT uses X-rays for imaging, there is a risk of radiation exposure. In contrast, MRI uses radiowaves and magnetic fields for imaging; thus, there are no reported biological hazards. However, neither MRI nor CT is suitable as a noninvasive imaging tool applicable in small laboratory animals such as zebrafish embryos or larvae. The recently established micro-CT scanner is only suitable for scanning adult fish and a staining procedure is required for imaging. In addition, CT-based scanning is generally more suitable for skeletal imaging but not for visualization of soft tissues because of its lower contrast. In this study, we evaluated whether 633 nm HeNe laser-coupled confocal microscope allows simulating MRI/CT scan and imaging soft tissues such as brain and eye in zebrafish embryos/larvae. We show that the 633 nm HeNe laser can penetrate well into intact brain and eye of zebrafish. It represents a noninvasive imaging method with high resolution while not requiring contrast agents, enabling the detection of differential signals from normal and pathological organs such as brain and eye.

  1. Imaging of the Eustachian tube and its function: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.E.; Tysome, J.R. [Cambridge University Hospitals NHS Foundation Trust, Department of ENT Surgery, Addenbrooke' s Hospital, Cambridge (United Kingdom); Scoffings, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2016-06-15

    The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function. A systematic review of the literature was performed with narrative data analysis. With high-resolution images, the soft and bony anatomy of the Eustachian tube can be assessed in detail. CT and MRI are best suited to identifying features associated with obstructive or patulous Eustachian tube dysfunction, though true assessments of function have only been achieved with contrast enhanced radiographs and scintigraphy. A single modality has yet to provide a complete assessment. No test has entered routine clinical use, but further development and research is underway. Significant information can be gained from imaging the Eustachian tube, and as faster acquisition techniques are developed, it is possible that dynamic imaging of tubal opening could play an important role in the assessment of patients with ET dysfunction. (orig.)

  2. Assessment of cerebral perfusional and functional connectivity in schizophrenia using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ícaro A. F.; Guimarães, Tiago M.; Souza, Roberto M.; Santos, Antônio C. dos; Leoni, Renata F.; Machado-Sousa, João Paulo; Hallak, Jaime E.C. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil)

    2017-07-01

    Schizophrenia is a significant mental disorder that compromises structural and functional aspects of the brain, with an extreme effect on the patient’s thoughts, feelings, and behavior. Physiologically, changes in neuronal activity are reported besides functional and structural abnormalities. Since the cerebral blood flow (CBF) is directly related to neuronal activity, the magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL), which allows the quantification of CBF, is a useful tool in brain perfusional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 schizophrenia patients in treatment and 28 age-matched healthy controls. Static CBF and connectivity patterns were assessed in both groups. Decreased CBF and functional connectivity were observed in regions that form two resting brain networks, default mode (DMN) and salience (SN), for schizophrenia patients. Previous studies related the features of this pathology with altered resting CBF and functional disconnections. Therefore, using a noninvasive technique, it was possible to find CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder. (author)

  3. Assessment of cerebral perfusional and functional connectivity in schizophrenia using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Oliveira, Ícaro A. F.; Guimarães, Tiago M.; Souza, Roberto M.; Santos, Antônio C. dos; Leoni, Renata F.; Machado-Sousa, João Paulo; Hallak, Jaime E.C.

    2017-01-01

    Schizophrenia is a significant mental disorder that compromises structural and functional aspects of the brain, with an extreme effect on the patient’s thoughts, feelings, and behavior. Physiologically, changes in neuronal activity are reported besides functional and structural abnormalities. Since the cerebral blood flow (CBF) is directly related to neuronal activity, the magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL), which allows the quantification of CBF, is a useful tool in brain perfusional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 schizophrenia patients in treatment and 28 age-matched healthy controls. Static CBF and connectivity patterns were assessed in both groups. Decreased CBF and functional connectivity were observed in regions that form two resting brain networks, default mode (DMN) and salience (SN), for schizophrenia patients. Previous studies related the features of this pathology with altered resting CBF and functional disconnections. Therefore, using a noninvasive technique, it was possible to find CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder. (author)

  4. Non-invasive assessment of liver fibrosis with impulse elastography: comparison of Supersonic Shear Imaging with ARFI and FibroScan®.

    Science.gov (United States)

    Cassinotto, Christophe; Lapuyade, Bruno; Mouries, Amaury; Hiriart, Jean-Baptiste; Vergniol, Julien; Gaye, Delphine; Castain, Claire; Le Bail, Brigitte; Chermak, Faiza; Foucher, Juliette; Laurent, François; Montaudon, Michel; De Ledinghen, Victor

    2014-09-01

    Non-invasive assessment of liver fibrosis by elastography is a rapidly developing field with frequent technological innovations. The aim of this study was to assess the diagnostic performances of Supersonic Shear Imaging (SSI) for the diagnosis of liver fibrosis in chronic liver disease. A total of 349 consecutive patients with chronic liver diseases who underwent liver biopsy from November 2011 to October 2013 were prospectively enrolled. For each patient, liver stiffness was assessed by SSI, ARFI, FibroScan® (M probe for patients with BMI liver biopsy. Areas under the receiver operating curves (AUROCs) were performed and compared for each degree of liver fibrosis. SSI, FibroScan®, and ARFI correlated significantly with histological fibrosis score (r=0.79, pliver fibrosis in chronic liver diseases, comparing favourably to FibroScan® and ARFI. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  5. Pre-clinical functional magnetic resonance imaging. Pt. I. The kidney

    International Nuclear Information System (INIS)

    Zoellner, Frank G.; Kalayciyan, Raffi; Chacon-Caldera, Jorge; Zimmer, Fabian; Schad, Lothar R.

    2014-01-01

    The prevalence of chronic kidney disease (CKD) is increasing worldwide. In Europe alone, at least 8% of the population currently has some degree of CKD. CKD is associated with serious comorbidity, reduced life expectancy, and high economic costs; hence, the early detection and adequate treatment of kidney disease is important. Pre-clinical research can not only give insights into the mechanisms of the various kidney diseases but it also allows for investigating the outcome of new drugs developed to treat kidney disease. Functional magnetic resonance imaging provides non-invasive access to tissue and organ function in animal models. Advantages over classical animal research approaches are numerous: the same animal might be repeatedly imaged to investigate a progress or a treatment of disease over time. This has also a direct impact on animal welfare and the refinement of classical animal experiments as the number of animals in the studies might be reduced. In this paper, we review current state of the art in functional magnetic resonance imaging with a focus on pre-clinical kidney imaging.

  6. Pre-clinical functional magnetic resonance imaging. Pt. I. The kidney

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, Frank G.; Kalayciyan, Raffi; Chacon-Caldera, Jorge; Zimmer, Fabian; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine

    2014-07-01

    The prevalence of chronic kidney disease (CKD) is increasing worldwide. In Europe alone, at least 8% of the population currently has some degree of CKD. CKD is associated with serious comorbidity, reduced life expectancy, and high economic costs; hence, the early detection and adequate treatment of kidney disease is important. Pre-clinical research can not only give insights into the mechanisms of the various kidney diseases but it also allows for investigating the outcome of new drugs developed to treat kidney disease. Functional magnetic resonance imaging provides non-invasive access to tissue and organ function in animal models. Advantages over classical animal research approaches are numerous: the same animal might be repeatedly imaged to investigate a progress or a treatment of disease over time. This has also a direct impact on animal welfare and the refinement of classical animal experiments as the number of animals in the studies might be reduced. In this paper, we review current state of the art in functional magnetic resonance imaging with a focus on pre-clinical kidney imaging.

  7. Dose modeling of noninvasive image-guided breast brachytherapy in comparison to electron beam boost and three-dimensional conformal accelerated partial breast irradiation.

    Science.gov (United States)

    Sioshansi, Shirin; Rivard, Mark J; Hiatt, Jessica R; Hurley, Amanda A; Lee, Yoojin; Wazer, David E

    2011-06-01

    To perform dose modeling of a noninvasive image-guided breast brachytherapy (NIIGBB) for comparison to electrons and 3DCRT. The novel technology used in this study is a mammography-based, noninvasive breast brachytherapy system whereby the treatment applicators are centered on the planning target volume (PTV) to direct (192)Ir emissions along orthogonal axes. To date, three-dimensional dose modeling of NIIGBB has not been possible because of the limitations of conventional treatment planning systems (TPS) to model variable tissue deformation associated with breast compression. In this study, the TPS was adapted such that the NIIGBB dose distributions were modeled as a virtual point source. This dose calculation technique was applied to CT data from 8 patients imaged with the breast compressed between parallel plates in the cranial-caudal and medial-lateral axes. A dose-volume comparison was performed to simulated electron boost and 3DCRT APBI. The NIIGBB PTV was significantly reduced as compared with both electrons and 3DCRT. Electron boost plans had a lower D(min) than the NIIGBB technique but higher V(100), D(90), and D(50). With regard to PTV coverage for APBI, the only significant differences were minimally higher D(90), D(100), V(80), and V(90), with 3DCRT and D(max) with NIIGBB. The NIIGBB technique, as compared with electrons and 3D-CRT, achieved a lower maximum dose to skin (60% and 10%, respectively) and chest wall/lung (70-90%). NIIGBB achieves a PTV that is smaller than electron beam and 3DCRT techniques. This results in significant normal tissue sparing while maintaining dosimetric benchmarks to the target tissue. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. 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

  9. Augmenting Melodic Intonation Therapy with non-invasive brain stimulation to treat impaired left-hemisphere function: two case studies

    Directory of Open Access Journals (Sweden)

    Shahd eAl-Janabi

    2014-02-01

    Full Text Available The purpose of this study was to investigate whether or not the right hemisphere can be engaged using Melodic Intonation Therapy (MIT and excitatory repetitive transcranial magnetic stimulation (rTMS to improve language function in people with aphasia. The two participants in this study (GOE and AMC have chronic non-fluent aphasia. A functional Magnetic Resonance Imaging (fMRI task was used to localize the right Broca’s homologue area in the inferior frontal gyrus for rTMS coil placement. The treatment protocol included an rTMS phase, which consisted of 3 treatment sessions that used an excitatory stimulation method known as intermittent theta burst stimulation, and a sham-rTMS phase, which consisted of 3 treatment sessions that used a sham coil. Each treatment session was followed by 40 minutes of MIT. A linguistic battery was administered after each session. Our findings show that one participant, GOE, improved in verbal fluency and the repetition of phrases treated with MIT in combination with TMS. However, AMC showed no evidence of behavioural benefit from this brief treatment trial. Post-treatment neural activity changes were observed for both participants in the left Broca’s area and right Broca’s homologue. These case studies indicate that a combination of rTMS applied to the right Broca’s homologue and MIT has the potential to improve speech and language outcomes for at least some people with post-stroke aphasia.

  10. Augmenting melodic intonation therapy with non-invasive brain stimulation to treat impaired left-hemisphere function: two case studies.

    Science.gov (United States)

    Al-Janabi, Shahd; Nickels, Lyndsey A; Sowman, Paul F; Burianová, Hana; Merrett, Dawn L; Thompson, William F

    2014-01-01

    The purpose of this study was to investigate whether or not the right hemisphere can be engaged using Melodic Intonation Therapy (MIT) and excitatory repetitive transcranial magnetic stimulation (rTMS) to improve language function in people with aphasia. The two participants in this study (GOE and AMC) have chronic non-fluent aphasia. A functional Magnetic Resonance Imaging (fMRI) task was used to localize the right Broca's homolog area in the inferior frontal gyrus for rTMS coil placement. The treatment protocol included an rTMS phase, which consisted of 3 treatment sessions that used an excitatory stimulation method known as intermittent theta burst stimulation, and a sham-rTMS phase, which consisted of 3 treatment sessions that used a sham coil. Each treatment session was followed by 40 min of MIT. A linguistic battery was administered after each session. Our findings show that one participant, GOE, improved in verbal fluency and the repetition of phrases when treated with MIT in combination with TMS. However, AMC showed no evidence of behavioral benefit from this brief treatment trial. Post-treatment neural activity changes were observed for both participants in the left Broca's area and right Broca's homolog. These case studies indicate that a combination of MIT and rTMS applied to the right Broca's homolog has the potential to improve speech and language outcomes for at least some people with post-stroke aphasia.

  11. Altered lymphatic function and architecture in salt-induced hypertension assessed by near-infrared fluorescence imaging

    Science.gov (United States)

    Kwon, Sunkuk; Agollah, Germaine D.; Chan, Wenyaw; Sevick-Muraca, Eva M.

    2012-08-01

    The lymphatic system plays an important role in maintaining the fluid homeostasis between the blood vascular and interstitial tissue compartment and there is recent evidence that its transport capabilities may regulate blood pressure in salt-induced hypertension. Yet, there is little known how the lymphatic contractile function and architecture responds to dietary salt-intake. Thus, we longitudinally characterized lymphatic contractile function and vessel remodeling noninvasively using dynamic near-infrared fluorescence imaging in animal models of salt-induced hypertension. The lymphatics of mice and rats were imaged following intradermal injection of indocyanine green to the ear tip or the base of the tail before and during two weeks of either a high salt diet (HSD) or normal chow. Our noninvasive imaging data demonstrated dilated lymphatic vessels in the skin of mice and rats on a HSD as compared to their baseline levels. In addition, our dynamic imaging results showed increased lymphatic contraction frequency in HSD-fed mice and rats. Lymphatic contractile function and vessel remodeling occurs in response to salt-induced hypertension suggesting a possible role for the lymphatics in the regulation of vascular blood pressure.

  12. Application platform 'ICX' designed for computer assisted functional image analyzer

    International Nuclear Information System (INIS)

    Kinosada, Yasutomi; Hattori, Takao; Yonezawa, Kazuo; Tojo, Shigenori.

    1994-01-01

    Recent clinical imaging modalities such as X-CT, MRI, SPECT and so on make it easy to obtain various functional images of the human body because of the rapid technical progress of modalities. But the technical progress such as fast imaging technique and 3D volume scanning technique have brought new problems for both medical doctors and technical staffs. They are the increase of both number of images and opportunities of the image processing for 3D presentations. Furthermore, it has been left difficult and troublesome to analyze these functional images. In this study, we have developed the application platform ICX (Independent Console based on X-window system) designed for a computer assisted functional image analyzer under the different concept from the conventional medical image processing workstations. ICX can manage clinical images from various modalities of imaging systems via Ethernet LAN and assist users to analyze or process these images easily with ICX's application programs or some commercial applications. ICX works as a diagnostic console, a personal PACS and a functional image analyzer, but independently works with imaging modalities. Many object-oriented image analysis and processing tools are available and they can be driven in any situations by users. ICX is a new type of the workstation and seems useful in the recent medical fields. (author)

  13. Functional cardiac imaging by random access microscopy

    Directory of Open Access Journals (Sweden)

    Claudia eCrocini

    2014-10-01

    Full Text Available Advances in the development of voltage sensitive dyes and Ca2+ sensors in combination with innovative microscopy techniques allowed researchers to perform functional measurements with an unprecedented spatial and temporal resolution. At the moment, one of the shortcomings of available technologies is their incapability of imaging multiple fast phenomena while controlling the biological determinants involved. In the near future, ultrafast deflectors can be used to rapidly scan laser beams across the sample, performing optical measurements of action potential and Ca2+ release from multiple sites within cardiac cells and tissues. The same scanning modality could also be used to control local Ca2+ release and membrane electrical activity by activation of caged compounds and light-gated ion channels. With this approach, local Ca2+ or voltage perturbations could be induced, simulating arrhythmogenic events, and their impact on physiological cell activity could be explored. The development of this optical methodology will provide fundamental insights in cardiac disease, boosting new therapeutic strategies, and, more generally, it will represent a new approach for the investigation of the physiology of excitable cells.

  14. Vision research with functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Nakadomari, Satoshi

    1999-01-01

    Present state of functional magnetic resonance imaging (fMRI), which is based on changes of MR signals produced by blood circulation changes due to the nerve activity, in vision research was reviewed. In this field, there are international associations of Human Brain Mapping and for Research in Vision and Ophthalmology (ARVO) and reports presented in ARVO in 1998 and 1999 were firstly described. Next, the comparison between two conditions was defined as the experimental paradigm of fMRI and analyses with the event related fMRI and with classification into visual central regions were explained. Major findings obtained by stimulation of visual central regions were discussed on the lateral corpus geniculatum, areas of V1, V2, V3 (VP), V3A, V4A (V8), V5 and LO (lateral occipital complex), and others. In practice of actual fMRI, the noise is often attributable to the examinee factor and notification for speculating the result is important. The value of fMRI in the clinical ophthalmological diagnosis was discussed and thought to be further investigated. (K.H.)

  15. Non-invasive detection of infection in acute pancreatic and acute necrotic collections with diffusion-weighted magnetic resonance imaging: preliminary findings.

    Science.gov (United States)

    Islim, Filiz; Salik, Aysun Erbahceci; Bayramoglu, Sibel; Guven, Koray; Alis, Halil; Turhan, Ahmet Nuray

    2014-06-01

    The purpose of this study was to evaluate the contribution of diffusion-weighted magnetic resonance imaging (DW-MRI) to the detection of infection in acute pancreatitis-related collections. A total of 21 DW-MRI, and computed tomography (CT) were performed on 20 patients diagnosed as acute pancreatitis with acute peri-pancreatic fluid or necrotic collections. Collections were classified as infected or sterile according to the culture and follow-up results. Collections with gas bubbles on CT images were considered to be infected. Collections with peripheral bright signals on DW-MRI images were considered to be positive, whereas those without signals were considered to be negative. Apparent diffusion coefficient (ADC) values of the peripheral and central parts of the collections were measured. Student's t test was used to compare the means of ADC values of independent groups. Apart from one false positive result, the presence of infection was detected by DW-MRI with 95.2% accuracy. The sensitivity and accuracy of DW-MRI were higher than CT for the detection of infection. The ADC values in the central parts of the collections were significantly different between the infected and sterile groups. DW-MRI can be used as a non-invasive technique for the detection of infection in acute pancreatitis-associated collections.

  16. Medical imaging

    CERN Document Server

    Townsend, David W

    1996-01-01

    Since the introduction of the X-ray scanner into radiology almost 25 years ago, non-invasive imaging has become firmly established as an essential tool in the diagnosis of disease. Fully three-dimensional imaging of internal organs is now possible, b and for studies which explore the functional status of the body. Powerful techniques to correlate anatomy and function are available, and scanners which combine anatomical and functional imaging in a single device are under development. Such techniques have been made possible through r ecent technological and mathematical advances. This series of lectures will review both the physical basis of medical imaging techniques using X-rays, gamma and positron emitting radiosiotopes, and nuclear magnetic resonance, and the mathematical methods used to reconstruct three-dimentional distributions from projection data. The lectures will trace the development of medical imaging from simple radiographs to the present-day non-invasive measurement of in vivo biochemistry. They ...

  17. Design and Experimental Evaluation of a Non-Invasive Microwave Head Imaging System for Intracranial Haemorrhage Detection.

    Directory of Open Access Journals (Sweden)

    A T Mobashsher

    Full Text Available An intracranial haemorrhage is a life threatening medical emergency, yet only a fraction of the patients receive treatment in time, primarily due to the transport delay in accessing diagnostic equipment in hospitals such as Magnetic Resonance Imaging or Computed Tomography. A mono-static microwave head imaging system that can be carried in an ambulance for the detection and localization of intracranial haemorrhage is presented. The system employs a single ultra-wideband antenna as sensing element to transmit signals in low microwave frequencies towards the head and capture backscattered signals. The compact and low-profile antenna provides stable directional radiation patterns over the operating bandwidth in both near and far-fields. Numerical analysis of the head imaging system with a realistic head model in various situations is performed to realize the scattering mechanism of haemorrhage. A modified delay-and-summation back-projection algorithm, which includes effects of surface waves and a distance-dependent effective permittivity model, is proposed for signal and image post-processing. The efficacy of the automated head imaging system is evaluated using a 3D-printed human head phantom with frequency dispersive dielectric properties including emulated haemorrhages with different sizes located at different depths. Scattered signals are acquired with a compact transceiver in a mono-static circular scanning profile. The reconstructed images demonstrate that the system is capable of detecting haemorrhages as small as 1 cm3. While quantitative analyses reveal that the quality of images gradually degrades with the increase of the haemorrhage's depth due to the reduction of signal penetration inside the head; rigorous statistical analysis suggests that substantial improvement in image quality can be obtained by increasing the data samples collected around the head. The proposed head imaging prototype along with the processing algorithm demonstrates

  18. 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.

    Science.gov (United States)

    Al Faraj, Achraf; Shaik, Abjal Pasha; Shaik, Asma Sultana

    2015-01-01

    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. 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. 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 inhibition following DOX-loaded SWCNTs injection. Magnetic tagging of SWCNTs was found to produce significant discrepancies in apparent diffusion coefficient values providing a higher contrast to detect treatment-induced variations as noninvasive imaging biomarker. In addition, it allowed their sensitive

  19. Non-invasive imaging of cardiac transgene expression with PET: comparison of the human sodium/iodide symporter gene and HSV1-tk as the reporter gene

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Masao; Haubner, Roland; Souvatzoglou, Michael; Schwaiger, Markus; Bengel, Frank M. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Nuklearmedizinische Klinik und Poliklinik, Muenchen (Germany); Anton, Martina; Gansbacher, Bernd [Technische Universitaet Muenchen, Institut fuer Experimentelle Onkologie und Therapieforschung, Munich (Germany); Wagner, Bettina [Technische Universitaet Muenchen, Klinikum rechts der Isar, Nuklearmedizinische Klinik und Poliklinik, Muenchen (Germany); Technische Universitaet Muenchen, Institut fuer Experimentelle Onkologie und Therapieforschung, Munich (Germany)

    2005-09-01

    Genes encoding for intracellular enzymes or transmembrane proteins are suitable as reporters, but may differ in terms of applicability for cardiac imaging. The aim of this study was to compare the human sodium iodide symporter gene (hNIS) with the herpes simplex virus type 1 thymidine kinase gene (HSV1-tk) as the reporter gene in non-invasive imaging of cardiac transgene expression with positron emission tomography (PET). Equal doses of adenoviral vectors encoding for hNIS, wild-type HSV1-tk, mutant HSV1-sr39tk or LacZ as the control gene were directly injected into the myocardium of 34 animals. Two days later, dynamic PET was performed with a clinical scanner, using reporter probes specific for the respective reporter gene. Imaging with {sup 13}N-ammonia was also performed to identify cardiac regions of interest. Kinetics differed significantly: {sup 124}I as the probe for hNIS showed rapid early uptake, remaining stable over time. Maximal myocardial concentration was 3.61{+-}1.15%. The nucleoside {sup 18}F-FHBG, as the specific probe for HSV1-sr39tk, showed increasing uptake over time, but maximal accumulation was significantly lower (1.45{+-}0.54%, P=0.0009). {sup 124}I-FIAU, as the specific probe for wild-type HSV1-tk, showed early uptake with subsequent washout. Maximal accumulation was lowest (0.63{+-}0.23%, P<0.0001). Post-mortem analysis by autoradiography and gamma counting confirmed the in vivo data. Reporter genes encoding for transporter proteins such as hNIS are an attractive alternative to overexpression of intracellular enzymes for cardiac gene product imaging. hNIS yielded higher signal intensity and imaging contrast for PET than did HSV1-tk and HSV1-sr39tk. Therefore, this approach may be preferable for the future monitoring of cardiac gene- or cell-based therapy. (orig.)

  20. 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 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.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.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.

  1. Non-invasive ventilation used as an adjunct to airway clearance treatments improves lung function during an acute exacerbation of cystic fibrosis: a randomised trial

    Directory of Open Access Journals (Sweden)

    Tiffany J Dwyer

    2015-07-01

    Full Text Available Question: During an acute exacerbation of cystic fibrosis, is non-invasive ventilation beneficial as an adjunct to the airway clearance regimen? Design: Randomised controlled trial with concealed allocation and intention-to-treat analysis. Participants: Forty adults with moderate to severe cystic fibrosis lung disease and who were admitted to hospital for an acute exacerbation. Intervention: Comprehensive inpatient care (control group compared to the same care with the addition of non-invasive ventilation during airway clearance treatments from Day 2 of admission until discharge (experimental group. Outcome measures: Lung function and subjective symptom severity were measured daily. Fatigue was measured at admission and discharge on the Schwartz Fatigue Scale from 7 (no fatigue to 63 (worst fatigue points. Quality of life and exercise capacity were also measured at admission and discharge. Length of admission and time to next hospital admission were recorded. Results: Analysed as the primary outcome, the experimental group had a greater rate of improvement in forced expiratory volume in 1 second (FEV1 than the control group, but this was not statistically significant (MD 0.13% predicted per day, 95% CI –0.03 to 0.28. However, the experimental group had a significantly higher FEV1 at discharge than the control group (MD 4.2% predicted, 95% CI 0.1 to 8.3. The experimental group reported significantly lower levels of fatigue on the Schwartz fatigue scale at discharge than the control group (MD 6 points, 95% CI 1 to 11. There was no significant difference between the experimental and control groups in subjective symptom severity, quality of life, exercise capacity, length of hospital admission or time to next hospital admission. Conclusion: Among people hospitalised for an acute exacerbation of cystic fibrosis, the use of non-invasive ventilation as an adjunct to the airway clearance regimen significantly improves FEV1 and fatigue. Trial

  2. 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.

  3. 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.

  4. Non-invasive, MRI-compatible fibreoptic device for functional near-IR reflectometry of human brain

    International Nuclear Information System (INIS)

    Sorvoja, H.S.S.; Myllylae, T S; Myllylae, Risto A; Kirillin, M Yu; Sergeeva, Ekaterina A; Elseoud, A A; Nikkinen, J; Tervonen, O; Kiviniemi, V

    2011-01-01

    A non-invasive device for measuring blood oxygen variations in human brain is designed, implemented, and tested for MRI compatibility. The device is based on principles of near-IR reflectometry; power LEDs serve as sources of probing radiation delivered to patient skin surface through optical fibres. Numerical Monte Carlo simulations of probing radiation propagation in a multilayer brain model are performed to evaluate signal levels at different source - detector separations at three operation wavelengths and an additional wavelength of 915 nm. It is shown that the device can be applied for brain activity studies using power LEDs operating at 830 and 915 nm, while employment of wavelength of 660 nm requires an increased probing power. Employment of the wavelength of 592 nm in the current configuration is unreasonable. (application of lasers and laser-optical methods in life sciences)

  5. Polymeric nanotheranostics for real-time non-invasive optical imaging of breast cancer progression and drug release.

    Science.gov (United States)

    Ferber, Shiran; Baabur-Cohen, Hemda; Blau, Rachel; Epshtein, Yana; Kisin-Finfer, Einat; Redy, Orit; Shabat, Doron; Satchi-Fainaro, Ronit

    2014-09-28

    Polymeric nanocarriers conjugated with low molecular weight drugs are designed in order to improve their efficacy and toxicity profile. This approach is particularly beneficial for anticancer drugs, where the polymer-drug conjugates selectively accumulate at the tumor site, due to the enhanced permeability and retention (EPR) effect. The conjugated drug is typically inactive, and upon its pH- or enzymatically-triggered release from the carrier, it regains its therapeutic activity. These settings lack information regarding drug-release time, kinetics and location. Thereby, real-time non-invasive intravital monitoring of drug release is required for theranostics (therapy and diagnostics). We present here the design, synthesis and characterization of a theranostic nanomedicine, based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, owing its fluorescence-based monitoring of site-specific drug release to a self-quenched near-infrared fluorescence (NIRF) probe. We designed two HPMA copolymer-based systems that complement to a theranostic nanomedicine. The diagnostic system consists of self-quenched Cy5 (SQ-Cy5) as a reporter probe and the therapeutic system is based on the anticancer agent paclitaxel (PTX). HPMA copolymer-PTX/SQ-Cy5 systems enable site-specific release upon enzymatic degradation in cathepsin B-overexpressing breast cancer cells. The release of the drug occurs concomitantly with the activation of the fluorophore to its Turn-ON state. HPMA copolymer-SQ-Cy5 exhibits preferable body distribution and drug release compared with the free drug and probe when administered to cathepsin B-overexpressing 4T1 murine mammary adenocarcinoma-bearing mice. This approach of co-delivery of two complementary systems serves as a proof-of-concept for real-time deep tissue intravital orthotopic monitoring and may have the potential use in clinical utility as a theranostic nanomedicine. Copyright © 2014. Published by Elsevier Ireland Ltd.

  6. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Unknown

    Abbreviations used: BOLD, Blood oxygenation level dependent; CBF, cerebral blood flow; fMRI, functional magnetic resonance imaging; EPI, eco-planar imaging; FOV, field of view; MRI, Magnetic resonance imaging; MRS, magnetic resonance spectroscopy;. PET, position emission tomography; rCBF, regional cerebral ...

  7. Color image coding based on recurrent iterated function systems

    Science.gov (United States)

    Kim, Kwon; Park, Rae-Hong

    1998-02-01

    This paper proposes a color image coding method based on recurrent iterated function systems (RIFSs). To encode a set of multispectral images, we apply a RIFS to multiset data consisting of three images. In the proposed method, the mappings not only between blocks within an individual spectral image but also between blocks of different spectral images are performed with contraction constraint. Simulation results show that the fractal coding based on the RIFS is useful for encoding concurrently a set of images by describing the similarity existing between a pair of images. In addition, the proposed color coding method can be applied to subband images and moving image sequences consisting of a set of images having similar gray patterns.

  8. 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

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

  9. 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

  10. Multiplanar spiral CT enterography in patients with Crohn's disease using a negative oral contrast material: initial results of a noninvasive imaging approach

    International Nuclear Information System (INIS)

    Reittner, Pia; Goritschnig, Toria; Doerfler, Otto; Petritsch, Wolfgang; Hinterleitner, Thomas; Preidler, Klaus W.; Szolar, Dieter H.

    2002-01-01

    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.)

  11. Synthesis of magnetic resonance–, X-ray– and ultrasound-visible alginate microcapsules for immunoisolation and noninvasive imaging of cellular therapeutics

    Science.gov (United States)

    Barnett, Brad P; Arepally, Aravind; Stuber, Matthias; Arifin, Dian R; Kraitchman, Dara L; Bulte, Jeff W M

    2011-01-01

    Cell therapy has the potential to treat or cure a wide variety of diseases. Non-invasive cell tracking techniques are, however, necessary to translate this approach to the clinical setting. This protocol details methods to create microcapsules that are visible by X-ray, ultrasound (US ) or magnetic resonance (MR) for the encapsulation and immunoisolation of cellular therapeutics. Three steps are generally used to encapsulate cellular therapeutics in an alginate matrix: (i) droplets of cell-containing liquid alginate are extruded, using an electrostatic generator, through a needle tip into a solution containing a dissolved divalent cation salt to form a solid gel; (ii) the resulting gelled spheres are coated with polycations as a cross-linker; and (iii) these complexes are then incubated in a second solution of alginate to form a semipermeable membrane composed of an inner and an outer layer of alginate. The microcapsules can be rendered visible during the first step by adding contrast agents to the primary alginate layer. Such contrast agents include superparamagnetic iron oxide for detection by 1H MR imaging (MRI); the radiopaque agents barium or bismuth sulfate for detection by X-ray modalities; or perfluorocarbon emulsions for multimodal detection by 19F MRI, X-ray and US imaging. The entire synthesis can be completed within 2 h. PMID:21799484

  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.

    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.

  13. 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

  14. Effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with COPD and type II respiratory failure

    Directory of Open Access Journals (Sweden)

    You-Ming Zhu1

    2017-03-01

    Full Text Available Objective: T o analyze the effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with chronic obstructive pulmonary disease (COPD and type II respiratory failure. Methods: 90 patients with COPD and type II respiratory failure were randomly divided into observation group and control group (n=45. Control group received conventional therapy, observation group received conventional therapy + adjuvant noninvasive positive pressure ventilation, and differences in blood gas parameters, cardiac function, inflammatory state, etc., were compared between two groups of patients 2 weeks after treatment. Results: Arterial blood gas parameters pH and alveolar-arterial partial pressure of oxygen [P(A-aO2] levels of observation group were higher than those of control group while, potassium ion (K+, chloride ion (Cl﹣ and carbon dioxide combining power (CO2CP levels were lower than those of control group 2 weeks after treatment; echocardiography parameters Doppler-derived tricuspid lateral annular systolic velocity (DTIS and pulmonary arterial velocity (PAV levels were lower than those of control group (P<0.05 while pulmonary artery accelerating time (PAACT, left ventricular enddiastolic dimension (LVDd and right atrioventricular tricuspid annular plane systolic excursion (TAPSE levels were higher than those of control group (P<0.05; serum cardiac function indexes adiponectin (APN, Copeptin, N-terminal pro-B-type natriuretic peptide (NT-proBNP, cystatin C (CysC, growth differentiation factor-15 (GDF-15 and heart type fatty acid binding protein (H-FABP content were lower than those of control group (P<0.05; serum inflammatory factors hypersensitive C-reactive protein (hs-CRP, tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β, IL-8, IL-10, and transforming growth factor-β1 (TGF-β1 content were lower than those of control group (P<0.05. Conclusions: Adjuvant

  15. Subband/Transform MATLAB Functions For Processing Images

    Science.gov (United States)

    Glover, D.

    1995-01-01

    SUBTRANS software is package of routines implementing image-data-processing functions for use with MATLAB*(TM) software. Provides capability to transform image data with block transforms and to produce spatial-frequency subbands of transformed data. Functions cascaded to provide further decomposition into more subbands. Also used in image-data-compression systems. For example, transforms used to prepare data for lossy compression. Written for use in MATLAB mathematical-analysis environment.

  16. Functional MR Imaging in Gynecologic Cancer.

    Science.gov (United States)

    deSouza, Nandita M; Rockall, Andrea; Freeman, Susan

    2016-02-01

    Dynamic-contrast enhanced (DCE) and diffusion-weighted (DW) MR imaging are invaluable in the detection, staging, and characterization of uterine and ovarian malignancies, for monitoring treatment response, and for identifying disease recurrence. When used as adjuncts to morphologic T2-weighted (T2-W) MR imaging, these techniques improve accuracy of disease detection and staging. DW-MR imaging is preferred because of its ease of implementation and lack of need for an extrinsic contrast agent. MR spectroscopy is difficult to implement in the clinical workflow and lacks both sensitivity and specificity. If used quantitatively in multicenter clinical trials, standardization of DCE- and DW-MR imaging techniques and rigorous quality assurance is mandatory. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Functional imaging of hepatic masses using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fujikawa, K.; Yamane, K.; Nakanishi, T.; Katsuta, S.

    1987-03-01

    In order to assess the usefulness of CT functional images, twenty one cases with liver masses were studied. We tried to minimize the motion artifacts by immobilizing the patients with a girdle in performing dynamic CT scans, and by discarding some of the segmented images with serious artifacts before constructing functional images. The qualities of images obtained were considered satisfactory. Of the several transit parameters obtained from the dynamic CT scans, we found the first moment (M1) to be most useful and the effectiveness of M1-functional images were studied. In all cases with hepatocellular carcinomas (12 cases) and intrahepatic cholangiocarcinomas (2 cases), the M1-functional images showed the viable portions of tumors as accumulations of dark pixels reflecting rapid transit times due to arterial blood supply. In three cases with hepatic cavernous hemangiomas, the lesions were represented as bright areas with a well-defined border. In two cases with hepatic abscesses, the M1-functional images suggested the presence of hyperemia in the surrounding tissue as demonstrated by bright pixels around the lesions. CT functional imaging was proved to be useful for evaluating the circulatory dynamics of contrast material and the differential diagnosis of liver tumors when conventional or dynamic CT studies failed to provide enough information. This technique enabled overall analysis of time-density curves for the entire plane of an image semiautomatically and without the subjective maneuver of setting ROI's (regions of interest).

  18. Generating text from functional brain images.

    Science.gov (United States)

    Pereira, Francisco; Detre, Greg; Botvinick, Matthew

    2011-01-01

    Recent work has shown that it is possible to take brain images acquired during viewing of a scene and reconstruct an approximation of the scene from those images. Here we show that it is also possible to generate text about the mental content reflected in brain images. We began with images collected as participants read names of concrete items (e.g., "Apartment'') while also seeing line drawings of the item named. We built a model of the mental semantic representation of concrete concepts from text data and learned to map aspects of such representation to patterns of activation in the corresponding brain image. In order to validate this mapping, without accessing information about the items viewed for left-out individual brain images, we were able to generate from each one a collection of semantically pertinent words (e.g., "door," "window" for "Apartment''). Furthermore, we show that the ability to generate such words allows us to perform a classification task and thus validate our method quantitatively.

  19. Noninvasive molecular imaging reveals role of PAF in leukocyte-endothelial interaction in LPS-induced ocular vascular injury.

    Science.gov (United States)

    Garland, Rebecca C; Sun, Dawei; Zandi, Souska; Xie, Fang; Faez, Sepideh; Tayyari, Faryan; Frimmel, Sonja A F; Schering, Alexander; Nakao, Shintaro; Hafezi-Moghadam, Ali

    2011-04-01

    Uveitis is a systemic immune disease and a common cause of blindness. The eye is an ideal organ for light-based imaging of molecular events underlying vascular and immune diseases. The phospholipid platelet-activating factor (PAF) is an important mediator of inflammation, the action of which in endothelial and immune cells in vivo is not well understood. The purpose of this study was to investigate the role of PAF in endothelial injury in uveitis. Here, we use our recently introduced in vivo molecular imaging approach in combination with the PAF inhibitors WEB 2086 (WEB) and ginkgolide B (GB). The differential inhibitory effects of WEB and GB in reducing LPS-induced endothelial injury in the choroid indicate an important role for PAF-like lipids, which might not require the PAF receptor for their signaling. P-selectin glycoprotein ligand-1-mediated rolling of mouse leukocytes on immobilized P-selectin in our autoperfused microflow chamber assay revealed a significant reduction in rolling velocity on the cells' contact with PAF. Rolling cells that came in contact with PAF rapidly assumed morphological signs of cell activation, indicating that activation during rolling does not require integrins. Our results show a key role for PAF in mediating endothelial and leukocyte activation in acute ocular inflammation. Our in vivo molecular imaging provides a detailed view of cellular and molecular events in the complex physiological setting.

  20. Noninvasive near infrared autofluorescence imaging of retinal pigment epithelial cells in the human retina using adaptive optics.

    Science.gov (United States)

    Liu, Tao; Jung, HaeWon; Liu, Jianfei; Droettboom, Michael; Tam, Johnny

    2017-10-01

    The retinal pigment epithelial (RPE) cells contain intrinsic fluorophores that can be visualized using infrared autofluorescence (IRAF). Although IRAF is routinely utilized in the clinic for visualizing retinal health and disease, currently, it is not possible to discern cellular details using IRAF due to limits in resolution. We demonstrate that the combination of adaptive optics (AO) with IRAF (AO-IRAF) enables higher-resolution imaging of the IRAF signal, revealing the RPE mosaic in the living human eye. Quantitative analysis of visualized RPE cells in 10 healthy subjects across various eccentricities demonstrates the possibility for in vivo density measurements of RPE cells, which range from 6505 to 5388 cells/mm 2 for the areas measured (peaking at the fovea). We also identified cone photoreceptors in relation to underlying RPE cells, and found that RPE cells support on average up to 18.74 cone photoreceptors in the fovea down to an average of 1.03 cone photoreceptors per RPE cell at an eccentricity of 6 mm. Clinical application of AO-IRAF to a patient with retinitis pigmentosa illustrates the potential for AO-IRAF imaging to become a valuable complementary approach to the current landscape of high resolution imaging modalities.

  1. What is feasible with imaging human brain function and connectivity using functional magnetic resonance imaging.

    Science.gov (United States)

    Ugurbil, Kamil

    2016-10-05

    When we consider all of the methods we employ to detect brain function, from electrophysiology to optical techniques to functional magnetic resonance imaging (fMRI), we do not really have a 'golden technique' that meets all of the needs for studying the brain. We have methods, each of which has significant limitations but provide often complimentary information. Clearly, there are many questions that need to be answered about fMRI, which unlike other methods, allows us to study the human brain. However, there are also extraordinary accomplishments or demonstration of the feasibility of reaching new and previously unexpected scales of function in the human brain. This article reviews some of the work we have pursued, often with extensive collaborations with other co-workers, towards understanding the underlying mechanisms of the methodology, defining its limitations, and developing solutions to advance it. No doubt, our knowledge of human brain function has vastly expanded since the introduction of fMRI. However, methods and instrumentation in this dynamic field have evolved to a state that discoveries about the human brain based on fMRI principles, together with information garnered at a much finer spatial and temporal scale through other methods, are poised to significantly accelerate in the next decade.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. © 2016 The Author(s).

  2. Noninvasive coronary artery imaging by multislice spiral computed tomography. A novel approach for a retrospectively ECG-gated reconstruction technique

    International Nuclear Information System (INIS)

    Sato, Yuichi; Kanmatsuse, Katsuo; Inoue Fumio

    2003-01-01

    Although the excellent spatial resolution of multislice spiral computed tomography (MSCT) enables the coronary arteries to be visualized, its limited temporal resolution results in poor image reproducibility because of cardiac motion artifact (CMA) and hence limits its widespread clinical use. A novel retrospectively electrocardiogram (ECG)-gated reconstruction method has been developed to minimize CMA. In 88 consecutive patients, the scan data were reconstructed using 2 retrospectively ECG-gated reconstruction methods. Method 1: the end of the reconstruction window (250 ms) was positioned at the peak of the P wave on ECG, which corresponded to the end of the slow filling phase during diastole immediately before atrial contraction. Method 2 (conventional method): relative retrospective gating with 50% referred to the R-R interval was performed so that the beginning of the reconstruction window (250 ms) was positioned at the halfway point between the R-R intervals of the heart cycle. The quality of the coronary artery images was evaluated according to the presence or absence of CMA. The assessment was applied to the left main coronary artery (LMCA), the left anterior descending artery (LAD, segments no.6, no.7, and no.8), the left circumflex artery (LCx, segments no.11 and no.13) and the right coronary artery (RCA, segments no.1, no.2 and no.3). The first diagonal artery (no.9-1), the obtuse marginal artery (no.12-1), the posterior descending artery (no.4-PD), the atrioventricular node branch (no.4-AV) and the first right ventricular branch (RV) were also evaluated. Of the 88 patients, 85 were eligible for image evaluation. Method 1 allowed visualization of the major coronary arteries without CMA in the majority of patients. The left coronary artery (LCA) system (segments no.5-7, no.11 and no.13) and the proximal portion of the RCA were visualized in more than 94% of patients. Artifact-free visualization of the distal portion of the LAD (segment no.8) and RCA (no.4

  3. [The influence of non-invasive electrical stimulation of the spinal cord on the locomotor function of patients presenting with movement disorders of central genesis].

    Science.gov (United States)

    Balykin, M V; Yakupov, R N; Mashin, V V; Kotova, E Yu; Balykin, Yu M; Gerasimenko, Yu P

    The objective of the present study was to evaluate the influence of non-invasive (transcutaneous) electrical spinal cord stimulation on the locomotor function of the patients suffering from movement disorders. The study involved 10 patients of both sexes at the age from 32 to 70 years (including 40% of men and 60% of women) presenting with the compromised locomotor function of varying severity associated with the disturbances of cerebral blood circulation caused either by an injury to the brain and spinal cord or by stroke. The transcutaneous electrical spinal cord stimulation was applied using different frequency regimes with the placement of the electrodes in the projection onto the region of TXI-TXII vertebrae. The active factors were bipolar electrical stimuli 0.5 ms in duration; the current strength was chosen for each patient on an individual basis taking into consideration its threshold level. Electromyograms and evoked motor responses of selected muscles, viz. m. rectus femoris, m.biceps femoris, m. tibialis anterior, and m.gastrocnemius were recorded with the use of the 'Neuro-MVP-8 eight-channel electromyography' ('Neurosoft', Russia). The data obtained give evidence that the stimulation of the spinal cord with a frequency of 1 Hz induces reflectory responses with monosynaptic and polysynaptic components in the muscles of the lower extremities, with the thresholds of these responses being significantly higher in the patients presenting with serious neurological problems. Stimulation with the frequencies of 5 and 30 Hz caused in the patients with paresis the involuntary movement of the legs the characteristics of which were similar to those of the locomotor movements. It has been demonstrated that the application of transcutaneous electrical spinal cord stimulation leads to increased excitability of the lumbar spinal neural structures of the patients. The study has shown the possibility of regulation of the locomotor functions in the patients presenting

  4. 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.

  5. Watching the Healing Brain: Multimodal and Non-invasive Imaging of Regenerative Processes after Experimental Cerebral Ischemia

    OpenAIRE

    Adamczak, Joanna Magdalena

    2013-01-01

    Stroke is a severe disease of the brain, which leads to cell death and loss of function. Neuroprotective therapy to prevent neuronal loss has not been effective in human stroke patients. Therefore, new therapeutic strategies are needed. Spontaneous recovery can be observed in some patients. However, the basis of this phenomenon is not completely understood yet. Several endogenous regenerative processes have been observed following cerebral ischemia, which may be the reason for functional reco...

  6. Estimating variability in functional images using a synthetic resampling approach

    International Nuclear Information System (INIS)

    Maitra, R.; O'Sullivan, F.

    1996-01-01

    Functional imaging of biologic parameters like in vivo tissue metabolism is made possible by Positron Emission Tomography (PET). Many techniques, such as mixture analysis, have been suggested for extracting such images from dynamic sequences of reconstructed PET scans. Methods for assessing the variability in these functional images are of scientific interest. The nonlinearity of the methods used in the mixture analysis approach makes analytic formulae for estimating variability intractable. The usual resampling approach is infeasible because of the prohibitive computational effort in simulating a number of sinogram. datasets, applying image reconstruction, and generating parametric images for each replication. Here we introduce an approach that approximates the distribution of the reconstructed PET images by a Gaussian random field and generates synthetic realizations in the imaging domain. This eliminates the reconstruction steps in generating each simulated functional image and is therefore practical. Results of experiments done to evaluate the approach on a model one-dimensional problem are very encouraging. Post-processing of the estimated variances is seen to improve the accuracy of the estimation method. Mixture analysis is used to estimate functional images; however, the suggested approach is general enough to extend to other parametric imaging methods

  7. Cardiac PET Imaging of Blood Flow, Metabolism, and Function in Normal and Infarcted Rats

    Science.gov (United States)

    Lecomte, R.; Croteau, E.; Gauthier, M.-E.; Archambault, M.; Aliaga, A.; Rousseau, J.; Cadorette, J.; Leroux, J.-D.; Lepage, M. D.; Benard, F.; Bentourkia, M.

    2004-06-01

    The rat heart is an excellent model for the investigation of cardiac physiology and metabolism. It has been used extensively for ex vivo studies of the normal heart as well as for the study of various heart diseases. With the advent of dedicated high-resolution small animal PET scanners, it is now possible to transpose many of the cardiac studies routinely used in humans to the rat. These include the in vivo measurement of myocardial blood flow, metabolism, and function. Because these techniques are noninvasive, the same animal can be imaged repetitively, thus allowing for follow-up studies of disease progression and for the assessment of new therapeutic methods. In this work, we report on cardiac studies performed in normal and diseased rats using the Sherbrooke avalanche photodiode PET scanner, a small animal PET imaging device achieving 14 /spl mu/l volumetric spatial resolution with excellent image signal-to-noise ratio. The system also features flexible list-mode data acquisition, which allows dynamic studies to be resampled as desired for kinetic modeling. These cardiac PET imaging methods were used for the follow-up of infarcted rats submitted to experimental intramyocardial revascularization therapy.

  8. Open framework for management and processing of multi-modality and multidimensional imaging data for analysis and modelling muscular function

    Science.gov (United States)

    García Juan, David; Delattre, Bénédicte M. A.; Trombella, Sara; Lynch, Sean; Becker, Matthias; Choi, Hon Fai; Ratib, Osman

    2014-03-01

    Musculoskeletal disorders (MSD) are becoming a big healthcare economical burden in developed countries with aging population. Classical methods like biopsy or EMG used in clinical practice for muscle assessment are invasive and not accurately sufficient for measurement of impairments of muscular performance. Non-invasive imaging techniques can nowadays provide effective alternatives for static and dynamic assessment of muscle function. In this paper we present work aimed toward the development of a generic data structure for handling n-dimensional metabolic and anatomical data acquired from hybrid PET/MR scanners. Special static and dynamic protocols were developed for assessment of physical and functional images of individual muscles of the lower limb. In an initial stage of the project a manual segmentation of selected muscles was performed on high-resolution 3D static images and subsequently interpolated to full dynamic set of contours from selected 2D dynamic images across different levels of the leg. This results in a full set of 4D data of lower limb muscles at rest and during exercise. These data can further be extended to a 5D data by adding metabolic data obtained from PET images. Our data structure and corresponding image processing extension allows for better evaluation of large volumes of multidimensional imaging data that are acquired and processed to generate dynamic models of the moving lower limb and its muscular function.

  9. WONOEP APPRAISAL: NEW SYSTEMIC FUNCTIONAL IMAGING TECHNOLOGIES TO STUDY THE BRAIN IN EXPERIMENTAL MODELS OF EPILEPSY

    Science.gov (United States)

    Dedeurwaerdere, Stefanie; Shultz, Sandy R.; Federico, Paolo; Engel, Jerome

    2014-01-01

    Summary Objectives Modern functional neuroimaging provides opportunities to visualize activity of the entire brain, making it an indispensable diagnostic tool for epilepsy. Various forms of non-invasive functional neuroimaging are now also being performed as research tools in animal models of epilepsy and provide opportunities for parallel animal/human investigations into fundamental mechanisms of epilepsy and identification of epilepsy biomarkers. Methods Recent animal studies of epilepsy using positron emission tomography, tractography, and functional magnetic resonance imaging were reviewed. Results Epilepsy is an abnormal emergent property of disturbances in neuronal networks which, even for epilepsies characterized by focal seizures, involve widely distributed systems, often in both hemispheres. Functional neuroimaging in animal models now provides opportunities to examine neuronal disturbances in the whole brain that underlie generalized and focal seizure generation as well as various types of epileptogenesis. Significance Tremendous advances in understanding the contribution of specific properties of widely distributed neuronal networks to both normal and abnormal human behavior have been provided by current functional neuroimaging methodologies. Successful application of functional neuroimaging of the whole brain in the animal laboratory now permits investigations during epileptogenesis and correlation with deep brain EEG activity. With the continuing development of these techniques and analytical methods, the potential for future translational research on epilepsy is enormous. PMID:24836499

  10. Mediastinal goiter diagnosed by functional imaging | Michels ...

    African Journals Online (AJOL)

    In the next step, we initiated radionuclide imaging with technetium-99m pertechnetate (Tc-99m) and radioiodine (I-123). Low uptake of Tc-99m and intense accumulation of I-123 after 2 and 24 h to the mediastinal mass suggested that the mass was a mediastinal goiter. Based on iodine uptake and the fact that our patient ...

  11. Noninvasive imaging of myocyte apoptosis following application of a stem cell-engineered delivery platform to acutely infarcted myocardium.

    Science.gov (United States)

    Godier-Furnémont, Amandine F G; Tekabe, Yared; Kollaros, Maria; Eng, George; Morales, Alfredo; Vunjak-Novakovic, Gordana; Johnson, Lynne L

    2013-06-01

    The cardioprotective effects of mesenchymal stem cells (MSCs) include reducing myocyte apoptosis, and this effect can be enhanced by preconditioning and encapsulation in a fibrin scaffold. This study aimed to test the hypothesis that apoptosis imaging can detect the cardioprotective effects of a conditioned MSC patch grafted in a rat model of acute myocardial infarction. Cell culture experiments simulating engraftment of fibrin patches onto beating rat ventricular myocytes exposed to hypoxia showed an effect of conditioned cells to reduce apoptosis. Twenty-three nude rats underwent successful left anterior descending coronary